JPH028603B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention involves blending inorganic filler fine particles with a polymerizable organic liquid monomer to polymerize and harden a dispersion liquid-like curable composition that contains a large amount but has good dispersion stability and fluidity. The present invention relates to molded articles with excellent properties and processability. The molded article of the present invention comprises:
By polymerizing and curing the raw material composition in a mold, it has a combination of stiffness, strength, and toughness, as well as other benefits such as good wear resistance and fire resistance. The molded article is made of a composite material that has excellent properties and has no cracks on its surface. More specifically, the present invention provides for stably and highly concentrated particles of at least one inorganic filler material in a polymerizable organic liquid, i.e., liquid organic monomer, in the presence of a polymeric dispersant. By molding a dispersed, fluid, polymerizable and curable organic monomer composition, and polymerizing and curing it in a mold, the organic polymer can be formed into a matrix of a molded article.
The present invention relates to a multicomponent composite molded article containing inorganic filler particles as a matrix (matrix) and dispersed and bonded in the matrix to act as a toughening agent. Traditionally, in order to reduce the price of organic polymers, to increase the hardness of polymer molded products, or for both purposes, non-fibrous filler particles have been added to polymers. It is known to extend. However, simply mixing such fillers with polymers usually results in molded articles that are extremely weak and brittle. It has recently been demonstrated that composite molded articles with improved strength can be obtained if a strong bond is created between the polymer matrix and the filler particles. Furthermore, it has been desired to incorporate a large amount of inorganic filler fine particles in order to strengthen and modify organic polymer molded articles. However,
Conventionally, the (apparent) viscosity of a mixture (slurry) made by dispersing solid particulate matter in a liquid is defined as the proportion of the total volume of solid particulate matter in the mixture, that is, the concentration (solid volume) measured in terms of volume. While the volume concentration is low, it increases only a little, but when it reaches a certain high concentration, it starts to increase rapidly, and by about 20 to 25%.
(volume), the viscosity reaches an unmeasurable height, so it was believed that there was a limit, or critical concentration, to the amount of solid particulate matter that could be added as long as such a mixture needed to have fluidity. .
Prior to the present invention, this conventional belief was stated in "Slurry Transport System Practical Application Technical Data Collection", pages 91-103, compiled by the Slurry Transport Research Group Materials Editorial Committee (Japan Technology and Economic Center, October 1972). month 7
This is clarified in figures and data (pages 91 to 99) in the Japanese publication). According to this literature, unless the solid particles are spherical, the apparent viscosity of a slurry-like mixture in which solid particles are suspended in a liquid has a small viscosity increase rate in a range where the solid volume concentration is low, but as the concentration increases, the viscosity increases rapidly. It has been shown that when the amount increases to 23 to 25%, depending on the type, size, shape, etc. of the particles, it becomes impossible to measure. A mixture whose viscosity cannot be measured, which contains particles with a volume higher than the critical concentration, is a hard paste that does not have enough fluidity for molding. It cannot be made into a molded product using molding methods such as casting. Therefore, in the conventional method of polymerizing and molding a mixture of liquid organic monomer and inorganic filler particles, in order to maintain fluidity, the solid volume concentration of the inorganic filler particles is low. Dispersions that are generally lower in concentration than the above-mentioned limit concentration, or much lower in low-pressure molding methods, can only be polymerized and molded. For example, in JP-A-48-68683, a specific organic monomer called a vinyl monomer is polymerized in the presence of fine inorganic filler particles whose dispersion is maintained by the thickening effect of a soluble polymer. By doing,
It has been proposed to manufacture a molded article of a vinyl polymer composite material in which hardness is enhanced by blending an inorganic filler with the produced vinyl polymer, but the inorganic filler and vinyl monomer to be blended are The type of inorganic filler to be used is limited depending on the strength of its affinity with Due to issues such as this, there is a limit to the amount of inorganic fillers that can be blended, and the upper limit of the amount is less than 30% based on the weight of the entire mixture of monomer and filler (depending on the specific gravity of the filler). However, when converted to solid volume concentration, it is approximately less than 15%). Moreover, in the method of Japanese Patent Application Laid-open No. 48-68683,
When producing a thermoplastic resin by making a dispersion of a vinyl monomer mixed with fine inorganic filler particles and bulk polymerizing it, a thermoplastic resin composition with uniform dispersion and excellent fluidity is required. For the purpose of manufacturing, the type of inorganic filler is selected based on its oil absorption amount, the amount of inorganic filler is limited to less than 30% by weight, and the amount of inorganic filler is limited to less than 30% by weight. In order to prevent the mechanically dispersed inorganic filler from settling again, a soluble vinyl polymer that acts as a thickener is dissolved in the vinyl monomer, and after stirring, bulk polymerization or stirring is performed. However, if the concentration of the filler particles becomes 30% or more by weight (which corresponds to approximately 15% or more by volume based on the specific gravity of the filler particles). It is stated in the above-mentioned publication that the polymerization operation becomes impossible, and this is because the concentration is far lower than the limit concentration of 23-25% (by volume) and sufficient fluidity is required for this technology. It can be seen that this technology involves adding much more monomer (liquid) than the amount of oil absorbed in order to give the same amount of oil. Furthermore, the present inventor has experimentally confirmed that in a mixture of a general liquid organic monomer and inorganic filler fine particles, the solid volume concentration of the filler is approximately 30% (by volume). ), the viscosity becomes unmeasurably high, resulting in a composition with extremely poor fluidity required for molding, and when it reaches approximately 50% (volume), particles cannot be sufficiently wetted, leaving mama powder. Only a hard, agglomerated, paste-like composition was obtained, which was considered unsuitable for conventional molding. The present inventors used inorganic filler fine particles to
It can be uniformly dispersed in a polymer matrix at solid particle volume concentrations near or above the aforementioned critical concentrations to provide improved hardness, strength, toughness and other properties compared to conventional composite materials. We carried out comprehensive research with the aim of obtaining composite materials with a wide range of uses. As a result, surprisingly, the mixture of the liquid organic monomer and the inorganic filler fine particles blended with the liquid organic monomer at a solid volume concentration of 30% or more (by volume) resembles a hard paste with extremely poor fluidity. Or, although it is like a hard paste containing mama flour, it is a liquid organic monomer, inorganic filler fine particles with a solid volume concentration of 30% (by volume) or more, and a certain amount of polymeric dispersant. The mixture as a whole can be formed into a fluid and uniform dispersion and can be molded by a conventional molding method, and the filler particles can be stably dispersed in the dispersion-like mixture. It has been recognized that mixtures of polymeric organic monomer liquids containing polymeric dispersants and filler particles with high solids volume concentrations can be used as well-flowing dispersion liquid molding compositions, and that such compositions It has been discovered that composite molded articles having the excellent properties described above can be formed directly from the composition by molding, polymerizing and curing. In other words, as a result of extensive research, the present inventors have found that a mixture of a filler containing fine inorganic filler particles and an organic monomer liquid exhibits fluidity to the extent that it is possible to measure the viscosity of the mixture. Although there is an upper limit to the solid volume concentration of the inorganic filler particles to be added to the mixture, that is, there is a critical concentration,
It has been discovered that incorporating a polymeric dispersant is effective as a means to increase the critical concentration of the filler. Moreover, the present invention solves the problem through the use of polymeric dispersants that have very high inorganic filler content, yet are easily molded and polymerized to form molded articles with excellent surface finish properties. The present invention provides a fluid polymerizable and curable molding composition that satisfies industrial demands for molded articles manufactured from the composition. Furthermore, since the molded article obtained according to the present invention has a high content of inorganic filler in terms of volume,
It is possible to exhibit the properties of an inorganic filler material rather than an organic polymer forming the matrix of the molded article, so that properties such as, for example, scratch strength, flame resistance, etc., are significantly improved. Furthermore, in general, when a molding composition is prepared by dispersing a volumetrically large amount of inorganic filler particles in a polymerizable organic monomer liquid to be polymerized and molded, it is necessary to have fluidity. In addition to there being
There are several problems as described below. That is, unless the inorganic filler can be maintained in the mixture as a stable dispersion and prevented from flocculation, the mixture containing the inorganic filler particles will not be suitable for molding compositions. The problem is that they are not useful as objects. That is, between the initial preparation of such a dispersed liquid mixture and the subsequent processing of the dispersed liquid mixture into a molded article, the dispersed filler particles irreversibly adhere to each other. This must be prevented. In the unlikely event that
If the filler particles are not prevented from agglomerating, the filler particles will agglomerate here and there and end up unevenly existing in the molded product obtained from it, and the intended effect of the filler formulation will not be achieved. Molded products also have drawbacks such as non-uniform structures. In a molding composition in which a large amount of inorganic filler fine particles are dispersed in a polymerizable organic monomer liquid, the filler fine particles are present in the dispersion with a high solid volume concentration. The total surface area of the particles becomes very large. In order to keep all of the filler particles intimately dispersed in the dispersion, the entire large surface of the filler particles must be sufficiently wetted with the organic liquid, and the dispersion must be shaped, polymerized, and cured. Throughout the curing stage, the filler particles have to be stabilized to maintain a sufficiently good dispersion. Unless the filler particles that come into contact with each other are prevented from agglomerating when they collide with each other in the dispersion due to Brownian motion or the like, agglomeration and segregation of the filler particles will occur. The state in which the filler particles are separated from each other in the dispersion, that is, the non-agglomerated state, must be maintained within the mold until the completion of curing.
In particular, if such a dispersion is to be sold as a molding composition without being immediately formed into a molded article,
The filler particles must remain in a stabilized, non-agglomerated state of dispersion so that even after long-term storage of the dispersion, a homogeneous dispersion can be easily reproduced by gentle stirring. In other words, even if the filler particles may settle due to their higher specific gravity than the organic liquid in the dispersion, gentle stirring will prevent the filler particles from agglomerating so that they can be easily and uniformly redispersed. There are problems that must be kept prevented. In this case, if the fluidity of the molding composition is low, the particles cannot be redispersed by gentle stirring, the molding operation becomes difficult, and the surface finish of the molded product is also poor. Another problem is that if the filler particles agglomerate or segregate to a significant extent during the actual polymerization and curing operations of such a dispersion, monomers will form within the dispersion during polymerization. The resulting molded product becomes non-uniform in each part, causing non-uniform shrinkage in each part, and as a result, cracks appear in the molded product. The temperature at which the dispersion is made and the temperature at which the dispersion is polymerized and processed into molded articles are different from each other, and because the dispersion is subjected to a wide range of temperature differences, non-uniform areas may occur during polymerization or curing. This must be avoided, and for this reason, the filler particles must be kept in a uniformly dispersed state throughout the process of molding the dispersion. The above-mentioned problem cannot be solved as the filler content increases, because when a large volume of filler particles are mixed into the dispersion, the probability that the filler particles will come into contact with each other increases rapidly. It becomes increasingly difficult. Even in the case of a molding composition formed by dispersing inorganic filler fine particles with a considerably high solid volume concentration in a polymerizable organic monomer, the present invention can be applied by using the polymeric dispersant described below. As a result, we succeeded in solving the various problems mentioned above. The physical and mechanical properties of the molded articles of the present invention made from molding compositions using polymeric dispersants according to the present invention are considerably improved, and their hardness, strength and toughness are significantly improved. Not only is the surface of the molded article significantly improved, but the surface of the molded article now takes on the characteristics of the filler material itself, rather than the properties of the organic polymer forming the matrix of the molded article. That is,
Properties such as scratch resistance and flame resistance are significantly enhanced. Such properties are not available in molded articles made from molding compositions comprising filler particles with a low solids volume concentration dispersed in a polymerizable organic monomer liquid. This is because the surface of the latter molded article has practically the same properties as the surface of the polymer forming the matrix of the molded article. Thus, in accordance with the present invention, a polymerizable organic polymer which can be polymerized and cured to produce a hardened solid organic polymer and which has a viscosity of 50 poise or less at the initial temperature during polymerization and shaping. liquid
(A) and the shear modulus dispersed in this organic liquid.
A fluid molding composition comprising fine particles (B) of at least one inorganic filler of 5 GN/m ² or more and an amphiphilic polymeric dispersant (C), the inorganic filler The fine particles (B) account for 35% to 90% (by volume) of the total volume of the molding composition, and account for all or substantially all of the inorganic filler fine particles present in the composition. The maximum particle size of the particles does not exceed 100 microns, and the particle size
% has a particle size of 10 microns or less, and the surface area of the particles is in the range of 30 m ² /cc to 1 m ² /cc; At least one (i) of a chain component with a molecular weight of 500 or more that is solvated by the organic liquid (A) and soluble in the organic liquid, and a chemical substance that is adsorbed on the surface of the inorganic filler fine particles (B). It is a polymeric substance containing in its molecule at least one group or component (ii) that is bonded to The inorganic filler fine particles (B) are blended in an amount of at least 0.01 g/m ² based on the total particle surface area of the particles (B), and the inorganic filler fine particles (B) are stably in a non-adhesive state in the polymerizable organic liquid (A). The molding composition, which is in the form of a dispersion liquid with good dispersion stability and is fluid even though it contains a high content of fine inorganic filler particles, is polymerized and further cured in a mold without mechanical stirring. A molded article made by curing the polymerizable organic liquid (A), wherein the inorganic filler particles
A molded article is provided comprising a cured organic polymer filled with particulate inorganic filler such that (B) is contained in an amount of 35 to 90% (by volume) of the molded article. The polymeric dispersant (C) used in the present invention is one in which each molecule of the dispersant has two different parts, that is, a chain component (i) with a molecular weight of 500 or more,
Another type of component or group attached to this chain component (ii)
It is characterized by being a substance consisting of one amphiphatic molecule composed of. Furthermore, the chain component (i) portion of the polymeric dispersant must be solvated by and soluble in the polymerizable organic liquid (A); second component or group of the agent (ii)
In the presence of fine inorganic filler particles, this portion becomes preferentially adsorbed or chemically bonded to the filler particle surface. Therefore, via the latter component or group (ii) of the polymeric dispersant, the polymeric dispersant molecules collect, attach, and anchor on the surface of the filler particles, and also form solvated soluble chains. It is presumed that component (i) extends outward into the organic liquid. Due to this, it is thought that the polymeric dispersant has the effect of preventing the inorganic filler particles from coming into contact with each other and agglomerating when they approach each other. In this case, the chain component (i) of the polymeric dispersant that is soluble in the organic liquid must have a molecular weight of 500 or more in order to achieve its intended effect. Apart from the chain component (i) of the polymeric dispersant (C) above, the component or group (ii) of the polymeric dispersant that is adsorbed or chemically bonded to the surface of the filler is this component. Alternatively, the degree to which the group (ii) is adsorbed or bound to the filler surface is sufficient to ensure that the inorganic filler remains uniformly dispersed and is prevented from agglomerating throughout the dispersion preparation stage, molding, and curing stage. Must be strong. As is clear from the above, the polymeric dispersant (C) used in the present invention significantly improves the fluidity of a composition consisting of an inorganic filler with a high solid volume concentration and an organic monomer liquid. In addition to this, it also has other remarkable effects. That is, the polymeric dispersant (C) enables a molding composition with a high solid volume concentration to be polymerized in a mold without stirring and without sedimentation of filler particles. Based on this, the molded articles of the invention obtained from this composition have the advantage of not cracking.
If the inorganic filler precipitates during the polymerization process of the composition, the raw material during polymerization in the mold will have partial regions with different filler contents, resulting in different shrinkage rates after polymerization. Therefore, cracks will occur. Furthermore, although the composition for producing the molded article of the present invention causes some sedimentation during long-term storage, when stored in a drum for a long period of time during transportation, a uniform dispersion can be obtained by simply rotating the drum. It is possible to restore the state of This is possible because the polymeric dispersant (C) maintains the filler particles in a stable, non-agglomerated state. Therefore, the polymeric dispersant used in the present invention not only imparts high fluidity to the molding composition, but also functions to maintain a high solid volume concentration of inorganic filler particles in a stable non-agglomerated state. Polymerization of the composition disperses the filler substantially uniformly throughout the molded article to impart desirable physical properties to the molded article. The "polymerizable organic liquid" used as component (A) in the present invention refers to one of the substances selected from the following groups (a), (b), and (c). (a) Polymerization changes the repeating units in the polymer chain to carbon-
A liquid monomer or a liquid mixture of two or more monomers capable of forming solid polymers linked by carbon bonds or carbon-carbon bonds with intervening foreign atoms such as oxygen, nitrogen or silicon. Preferably, polymerization of this monomer occurs without the formation of liberated by-products. In other words, preferred monomers are those that polymerize through bond rearrangement reactions. Such polymerization reactions may be of the following types: (i) Vinyl, vinylidene or other similarly unsaturated monomers are reacted with conventional free radical initiators such as peroxides or azo compounds or with conventional cations or addition polymerization in the presence of an anionic initiator; (ii) addition polymerization of ring-opening cyclic monomers using a cationic or anionic initiator; (iii) if desired in the presence of a conventional catalyst. A reaction that causes bond rearrangement type condensation. Examples of preferred liquid monomers for the reaction of type (i) are acrylic acid and methacrylic acid, and
Esters with 18 aliphatic, cycloaliphatic or aromatic alcohols; e.g. methyl methacrylate,
Ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethyl hexyl acrylate, ethylene glycol dimethacrylate, trimethylol propane trimethacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate , ethylenically unsaturated monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; vinyl aromatic compounds such as styrene, vinyltoluene and divinylbenzene, and combinations of these compounds with chlorophenylmaleimide and monobutyl.
mixtures with maleic acid or fumaric acid derivatives such as maleate; allyl ethers and esters such as allyl diglycol dicarbonate; and vinyl esters, vinyl ethers, vinyl chloride, such as acrylonitrile, methacrylonitrile, vinyl acetate; Other monomers such as vinylidene chloride and vinylpyrrolidone. Examples of liquid monomers preferred for reactions of type (ii) above are epoxides such as cyclic ethers, especially glycidyl ethers, such as alkyl- and aryl glycidyl ethers, and "Cardura" E (which is similar to epichlorohydrin and "Versatic "It is the reaction product of a mixture of branched chain monocarboxylic acids having 9 to 11 carbon atoms known as Acid(R)". Other examples are formals such as trioxane; lactones and cyclic esters such as β-propiolactone and ε-caprolactone; latakums and cyclic amides such as ε-caprolactam, lauryllactam and pyrrolidone; cyclic siloxanes such as octamethyl cyclotetrasiloxane. etc. Further examples of a preferred group of liquid monomers are co-reactants of the following combinations polymerized by reactions of type (iii) above; polyamines and polyisocyanates, polyols and polyisocyanates and polycarboxylic acids (or its anhydride) and polyepoxide. A suitable polyamine is ethylenediamine,
These include hexamethylene diamine, decamethylene diamine, diethylene triamine, piperazine, m- and p-xylylene diamine, m- and p-phenylene diamine, and the like. Suitable polyols include ethylene glycol, diethylene,
Glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, tetramethyl ethylene glycol, neopentyl glycol trimethylol
These include propane, glycerin, 1,2,6-hexanetriol, 1,3- and 1,4-cyclohexane diol, p-xylylene glycol, and the like. Suitable polyisocyanates are hexamethylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate, 4,4'-
These include diisocyanato, diphenyl, methane, etc. Suitable polycarboxylic acids or anhydrides thereof include succinic acid, adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, 1,3- and 1,4-cyclohexane dicarboxylic acid, and the like. Suitable polyepoxides are 1,4-butane diol, glycerin, resorcinol and the glycidyl ether of bisphenol A; bis-2,3-epoxy cyclopentyl ether, and the like. (b) A mixture of at least one preformed polymer and at least one monomer that can be polymerized to give a solid polymer product. The monomers can be the same as those described under (a) above, but again those that undergo bond rearrangement type polymerization are preferred. The preformed polymer used in this case (hereinafter also simply referred to as preformed polymer) can be dissolved or dispersed in the monomer component, and the polymer can be It may be the same as or different from the polymer produced by polymerizing the monomer components. If the preformed polymer is soluble in the monomer component, it may be miscible or immiscible with the polymer produced by polymerization of the monomers. The polymer may also undergo grafting with monomers. The preformed polymers used can be produced by any polymerization method, and for this purpose it is immaterial whether by-products are formed during the polymerization. For example, the polymer can be produced by polymerization in the melt or solution, by suspension polymerization, or by aqueous or non-aqueous dispersion polymerization and isolated by conventional methods. If the preformed polymer is to be present in the polymerizable liquid in the form of dispersed colloidal particles insoluble therein, these particles can be formed by grinding the bulk polymer to the required particle size; Conveniently, it is formed directly by using aqueous or non-aqueous dispersion polymerization techniques. Aqueous dispersion polymerization methods are explained in detail in known literature, and non-aqueous polymerization methods are also available, for example in British Patent Nos. 941305, 1052241, 1122397.
No., No. 1123611, No. 1143404 and No. 1231614
It is stated in the specification of the No. By using a preformed polymer that is immiscible with the polymer formed by the curing of the monomer component of the polymerizable organic liquid in the molding composition used as the raw material for making the shaped articles of the invention. Thus, the polymer matrix of the final molded article itself consists of a continuous phase component consisting of the polymer formed during the polymerization and curing of the molding composition, and particles of the preformed polymer dispersed in this continuous phase. The final result is a composite which is a modified composite phase, usually having a dispersoid component consisting of: Modifications can thus be made, for example, by dispersing and incorporating preformed rubbery polymer particles into a brittle polymer matrix. Alternatively, the rubbery polymer can be present initially dissolved in the monomer and allowed to phase separate as the polymerization proceeds. As a further alternative, strong ionic bonding forces can be created at the interfaces between the phases of the polymer. Such techniques are well known in the polymer dispersion and composites art. Examples of mixed systems of polymers and monomers that are suitably used as polymerizable organic liquids in the molding compositions used as raw materials in the present invention include: (1) (i) unsaturated; At least reactive polymers such as hydroxy alkyl acrylic acid or methacrylic acid ester adducts of aminoplasts such as polyesters, vinyl- or vinylidene-terminated urethanes, melamine-formaldehyde resins, and acrylic acid or methacrylic acid adducts of epoxy resins. syrup dissolved in an ethylenically unsaturated monomer; and (ii) α,
Mixtures of polyhydroxy polymers such as ω-hydroxy polyethers, polyesters or polybutadiene with polyisocyanates; and (iii) polyepoxide-containing polymers such as epoxidized polybutadiene and novolaks or oligomeric diglycidyl ethers of epichlorohydrin and bisphenol A. and a polyamine or anhydride; (2) a syrup of unreacted polymer dissolved in the monomer; in which the polymer formed during polymerization curing is miscible with the preformed polymer; (methyl methacrylate)/methyl methacrylate and poly(2,6-dimethylphenylene oxide)/styrene. Immiscible polymers include polyisoprene/acrylonitrile, poly(butyl acrylate)/methyl methacrylate; and cellulose acetate butyrate/methyl methacrylate; (3) monomers that do not dissolve the polymer; Encapsulated polybutadiene microgels with cross-linked poly(methyl methacrylate) dispersed in methyl methacrylate monomer; polyacrylonitrile dispersed in methyl methacrylate or butyl acrylate. ; cross-linked poly(butyl acrylate) dispersed in acrylonitrile;
and polyvinyl chloride dispersed in methyl methacrylate. (c) Substances, ie prepolymers, which are fully polymerizable by any known polymerization mechanism, preferably by the bond rearrangement mechanism described in (a) above, but which are only partially polymerized. Such prepolymers are obtained by partial polymerization reactions of low molecular weight unsaturated oligomers such as 1,2-unsaturated polybutadiene and vinyl-terminated polyesters; polyepoxides such as epoxidized novolaks and polybutadiene; and materials capable of undergoing stepwise polymerization. ie, prepolymers that undergo a high degree of monomer to polymer conversion to yield high molecular weight products. Examples of these substances include combinations of coreactants as described in (a) above, which polymerize by reactions of type (iii) above. The polymerizable liquid (A) in the molding composition used in the present invention is such that a crystalline polymer or an amorphous polymer is produced during polymerization, regardless of the above (a), (b), or (c). In the latter case the polymer is an amorphous or rubbery polymer, ie a material which may have a glass transition temperature above or below ambient temperature, respectively. Non-reactive plasticizers that are conventionally used in combination with these polymers may be incorporated into these polymers. In defining that the polymerizable organic liquid (A) has a viscosity of 50 poise or less at the temperature at which the composition is molded, this temperature is the temperature at which the viscosity of the liquid is such that the composite molded article can be formed from the composition. This takes into account the fact that temperature is a practically important factor for formation. If the viscosity at this molding temperature is too high, the ease with which the composition can be molded will be reduced. However, if the molding is carried out at a temperature higher than room temperature, the monomer of the organic liquid (A) may have a viscosity higher than 50 poise at room temperature, since viscosity usually decreases with increasing temperature. The temperatures at which the composition is molded and cured do not necessarily have to be the same. The viscosity of the polymerizable organic liquid (A) is preferably 10 poise or less, preferably 1 poise or less at the molding temperature. The particulate inorganic filler (B) stably dispersed in the polymerizable organic liquid (A) is a solid material with a high shear modulus, that is, 5 GN/m ² or more, preferably 10 GN/m ² or more. It is characterized by Alternatively, a suitable filler solid material can be defined as a material with a Knoop hardness greater than 100. Examples of suitable inorganic filler solid materials are alumina, quartz, silica-based materials such as cristobalite and tridymite, kaolin and its calcined products,
Fluorite, kyanite, olivine, nepheline, syenite, sillimanite, zircon, wollastonite, apatite,
Nepheline, calcite, rhodostone, barite, gypsum and other metal silicates, aluminates, aluminosilicates,
various minerals such as phosphates, sulfates, carbonates, sulfides, carbides and oxides; metals which may be brittle or ductile such as cast iron, zinc alloys, aluminium, bronze and copper; and glass, ceramics, slag and coke. It is an artificial material such as carbon-based material. The inorganic filler particles used in this invention are fine if the maximum size of all or substantially all of the particles present does not exceed 100 microns, and at least 95% of the particles (by number) )
means that the particle size is less than 10 microns.
Preferably, 99% or more of the particles, calculated by the number of particles, have a particle size of 10 microns or less, and in general, the closer the ratio of the number of particles of 10 microns or less to 100%, the better.
For example, the proportion of particles smaller than 10 microns is 99.999
%, very satisfactory results are obtained. At the same time, it is preferred that the maximum particle size of all or substantially all of the particles present does not exceed 75 microns, preferably 50 microns. Fine particles of inorganic filler that meet the above particle size definition are separately
30-1 m ² /cc as measured by BET nitrogen adsorption method,
It is preferably defined as having a surface area of 20 to 2 m ² /cc. The inorganic filler particles may have a broad or narrow particle size distribution and may be monomodal or polymodal within the aforementioned particle size ranges. Particle size of a filler refers to the largest three-dimensional dimension of the particles, and the shape of the particles can vary from granules to tabular, cylindrical, rod-like, or ellipsoidal. In general, it is preferable for particles to be in the form of granules rather than in the form of a plate or a rod. This is because it becomes optimal. However, special applications may include particles with a length-to-diameter or length-to-thickness ratio of less than 25:1, such as asbestos, wollastonite, silicon carbide or silicon nitride "whiskers", kaolin or aluminum or mica plates. Certain particles consisting of shaped crystals can be used. The particulate filler may be one type of the above substances, or may be a mixture of two or more types. Filler particles can be formed by precipitation or comminution or from bulk materials by conventional grinding or grinding methods. This will be explained in detail later. Preferably, the surface of the filler particles is free of at least loosely bound water, and removal of such water is accomplished, for example, by heating the particles to 150°C. In some cases, such as when using a silane interfacial binder as described below, it is advantageous to sinter the particles at temperatures above 400°C. It is important that the inorganic filler particles used are not contaminated with artificially introduced low molecular weight surfactants such as fatty acids or their salts (commercial fillers are often treated with this). It is. As mentioned above, the molding composition used in the present invention contains 35% by volume to 35% by volume of a stably dispersed particulate inorganic filler.
Contains in an amount of 90% by volume. To impart the most advantageous properties to the composite obtained by curing the composition, the preferred solids volume concentration of filler will depend in part on the nature of the solid polymer formed in the polymerization curing step. When the solid polymer is amorphous or vitreous or crystalline, the preferred volume concentration of filler is from 35 to 85% based on the total composition.
% by volume, more preferably 50-80% by volume. If the filler particles become more strongly bound to the solid polymer matrix by the additional incorporation of a low molecular weight binder, as detailed below, even at such filler concentrations, the unmodified solid polymer Compared to the case
The hardness and strength of the resulting composite after curing can be significantly increased without significant loss of toughness. If the solid polymer forming the matrix of the molded article is rubbery and the filler particles are strongly bonded to it, the preferred volume concentration of filler is between 35 and 50%, based on the total composition; The elongation at break and tear strength of the composite after curing are significantly better than that of the unmodified polymer, and its hardness increases moderately. However, filler volume concentrations of 50% by volume or higher can also be used in applications as compression blocks for bridges, mounting blocks for machines or sealing gaskets when incorporated in suspension in rubbery polymers. The polymeric dispersant (C) used in the molding composition used in the present invention is as defined above and is a polymeric dispersant that is solvated by and soluble in the polymerizable organic liquid (A). amphiphilic, containing at least one chain component of molecular weight of both 500 and 500 (in the sense that the polymerizable organic liquid will solvate significantly better than its theta solvent if a portion of this component exists as an independent molecule); It is a substance. The properties of the θ solvent can be found in the “Polymer Handbook” (Interscience,
1966) and “Principles of Polymer
Chemistry, Chapters 12-14 (1953).More simply, the polymerizable organic liquid (A) is a "good" solvent for the chain components of the polymeric dispersant (C). Furthermore, this polymeric dispersant
(C) includes, in addition to the above-mentioned chain component (i) with a molecular weight of 500 or more,
At least one atomic group (group) or component adsorbed or chemically bonded to the particle surface of the inorganic filler (B)
(ii) (hereinafter sometimes simply referred to as an anchor group) in the molecule. It is estimated that the polymeric dispersant (C) is attached to and anchored to the surface of the inorganic filler particles by this anchoring group, so that many molecules of the polymeric dispersant surround the filler particles. By keeping the chain components of the polymeric dispersant with a molecular weight of 500 or more in a compatible state with the organic liquid (A), it is possible to maintain extremely uniform dispersion of the inorganic filler particles in the organic liquid. It is. Polymeric dispersants (C) suitable for use in the present invention can be classified into the following types, examples of each type are given in the table below: (1) A single tethering group as described above (ii) A simple polymer or copolymer chain that can be solvated by a polymerizable organic liquid terminated in These polymers can generally be represented by the formula It is a mooring group. This tethering group is explained in more detail below and is, for example, a carboxyl group, an amino group, a sulfate group or a hydroxyl group, which is present from the appropriate (co)monomeric units or during the formation of the polymer chain. can be derived from chain transfer agents.
When the polymer chain (Xn) is independent,
It has a molecular weight of at least 500, preferably greater than 1500. (2) A random copolymer in which some of the monomer units constituting the random copolymer carry a large number of anchoring groups attached to the filler particle surface, and the copolymer can be solvated by a polymerizable organic liquid. Combined. These random copolymers have the formula ---
XXXYYXXXXY--, where X is a monomer unit that imparts solubility in the polymerizable organic liquid to the polymer chain constructed from it, and Y is a specific ( specific) is a monomer unit with a tethering group. Such random copolymer preferably has 3000
It is better to have a larger molecular weight. The monomer unit having the tethering group is 1 to 20% by weight, preferably 1.5 to 15% of the total random copolymer,
More preferably, it constitutes 2 to 10%. (3) Simple or multiple block copolymers: (i) simple AB type block copolymers, where A is a polymer or copolymer chain that can be solvated by a polymerizable organic liquid; and B thus represents a polymer chain that is not solvated and acts as a tethering group. The molecular weight of block portion A is 500 or more, preferably 1500 or more, and the weight ratio of A block A to block B is preferably 3:
The ratio is 1 to 1:3. (ii) multiple block copolymers, e.g.
A block copolymer represented by AmBnAoBp---. Here, A and B have the same meanings as in (i) above, and m, n, o, p-- indicate the various lengths of the polymer chains in each block row. The molecular weight of each block A is preferably 1500 or more, and the molecular weight of each block B is preferably 500 or more. The weight ratio of block A and block B is preferably the same as in case (i). (4) Graft copolymers, which include the following three types: where A represents a polymer chain that can be solvated by a polymerizable organic liquid and B represents a polymer chain that is thus unsolvated, m, n, o, p--
indicate the various lengths of chains A and B, and C is (i)
In types (ii) and (iii), D represents a monomer that provides a polymer backbone that may or may not be solvated by a polymerizable liquid; It is a monomer unit having a specific tethering group similar to monomer unit Y in (2) above. In these graft copolymers the solvable A chains have a minimum molecular weight of 500.
The weight ratio between the A chain and the C unit chain in type (i) or the A chain and the chain of C units and D units in type (ii) is preferably 3:1 to 1:3, preferably 1:1. Preferably close. The D monomer units in type (ii) should be present in the proportions described above for Y units in case (2). In type (iii), the molecular weight of the B chain is greater than 500, and if the chain of C units can be solvated, then (A+C) and B
The weight ratio of and the weight ratio of B:C should also be within this range, preferably about 1:1. When selecting the polymeric dispersant (C) to be used, it should be noted that even if it is an amphiphilic substance, it should be considered that the substance as a whole does not act as a dispersant but in effect as a flocculant for the particulate filler. It is important to avoid amphiphilic substances, especially those falling into types (2) and (4) above, which carry several tethering groups on the solvable polymer chain in a non-uniform manner. The polymeric dispersant used in the present invention is placed in the organic liquid (A) and forms a normal three-dimensional structure at the interface between the particle surface of the inorganic filler (B) and the organic liquid phase. When taking the coordination state, it adheres to the filler particle surface,
It can be said that it is a polymeric material in which the concentration (number) of the above-mentioned tethering groups existing outside or near the sheath consisting of a group of tethered polymeric dispersant molecules is reduced. On the other hand, in the above case, the flocculant can be said to be a substance that has a high concentration of anchoring groups present outside or in the vicinity of the envelope layer of flocculant molecules that adhere to and surround the surface of the inorganic particles. It is within the skill of those skilled in the art to determine the molecular type and precise conditions for the dispersant material that will provide a dispersing rather than aggregating action. The following table summarizes examples of dispersant types.

【table】

[Table] The polymeric dispersant used in the present invention (or the reaction product generated from the polymeric dispersant obtained during curing of the molding composition containing the same) is used in the curing operation of the present composition. Throughout the process,
It should remain solvated or compatible with the oligomeric or polymeric product being formed, thus preventing agglomeration or agglomeration of the inorganic filler particles among themselves and preventing the polymeric dispersion. The agent should become intimately incorporated or bonded or fixed in the polymer of the matrix forming the composition (molded article) after curing, and this is one of the basic principles of the present invention. It is a unique feature. However, this requirement does not apply if any portion of the molecules of the polymeric dispersant are chemically linked to the preformed polymer in the polymerizable organic liquid (A) or to the oligomeric component derived from the organic liquid (A). It does not necessarily mean that it must be the same or similar or that it must be chemically identical or similar to the solid polymer formed upon curing. A polymer containing as a component to be solvated a polymeric (chain) component that is compositionally identical or closely related to the solid polymer ultimately formed upon curing of the composition. If a cohesive dispersant is selected, it is practically possible to maintain the above-mentioned state of compatibility throughout the curing operation. However, the solvated polymer chains of the polymeric dispersants according to the invention have functionalities that allow grafting or copolymerization with the monomers present in the polymerizable organic liquid (A) to occur during the curing process. It can also contain groups. Grafting, in the case of addition polymerization of vinyl or vinylidene monomers, involves adding copolymerizable methacrylate groups into the polymeric dispersant molecule in the manner described, for example, in GB 1052241.
Alternatively, it can be carried out by introducing a group that is susceptible to hydrogen elimination in the presence of active radicals obtained by decomposition of peroxide. When a thermosetting polymer is formed upon curing of a polymerizable organic liquid, it can be grafted or Copolymerization can be achieved. The solvating component (i) of the polymeric dispersant (C) has a molecular weight such that when it is introduced into the polymer matrix after curing of the composition it does not have any adverse effect on the mechanical properties of the polymer. and/or co-reactive. Lower limit value determined for effective stabilization of inorganic particle dispersion (molecular weight 500)
When a solvating component (ii) is used in the polymeric dispersant with a molecular weight close to or other reactive groups. It will therefore be appreciated that the suitability of the solvable component (i) of a particular polymeric dispersant (C) will depend on the choice of polymer matrix. As mentioned above, the tethering group (ii) present in the polymeric dispersant (C) can be roughly classified into two types. The first type is one that has a fairly specific affinity for the surface of the inorganic particle.
Such groups include polar or chemically reactive groups that are complementary to polar or reactive groups present on the surface of the inorganic particles. These groups may be defined in detail as follows: - (i) groups that are likely to give rise to a form of ionic bonding with inorganic particles, such as salt-like bonds with metal ions in inorganic particles or with inorganic particles; carboxylic or sulfonic acid groups capable of forming base-like centers in the particles, or amino or quaternary ammonium groups capable of forming such bonds with acidic centers in the inorganic particles; (ii) ) Groups possibly forming covalent bonds with the inorganic particles, such as isocyanate groups or alkoxysilane groups capable of reacting with hydroxyl centers in the particles or chelatable centers in the particles. chromic chloride or other chelating agent; (iii) groups that are likely to form hydrogen bonds between the polymeric dispersant and the inorganic particles, such as carboxylic acid groups that can interact with hydroxyl groups in the particles; (iv) ) A group that causes physical adsorption onto the surface of an inorganic particle, for example, by dipole-dipole interaction or Van der Waals force, such as a nitro group, a cyano group, an ester group, an amide group, and a betaine group; Their weak interactions can be strengthened by sequentially attaching these groups to relatively insoluble polymer chains. The second type of tethering group (ii) in the polymeric dispersant is a polymer that is relatively unsolvated by the polymerizable organic liquid (A) compared to the aforementioned solvated polymer chain (i). A polymer chain in which each segment has at least a small but non-specific affinity for the inorganic particle. Such polymer chains (groups)
An example is a poly(acrylic ester) or poly(methacrylic ester) chain (in which case the carboxylic ester group performs the mooring action by the collective force of the whole), or an aromatic ring performs such an action. It is a polystyrene chain. If desired, anchoring groups of both the specific and non-specific types described above can be used. Additionally, some polymeric dispersants suitable for use in particular cases are described in more detail. Examples of particularly suitable polymeric dispersants for use in the case of addition polymers derived from at least one unsaturated monomer or syrups of high molecular weight polymers dissolved in such monomers are: It has the same molecular type as the polymer that makes up the molded product matrix,
It is a polymer having a molecular weight of 20,000 to 200,000 and having a large number of tethering groups distributed along the polymer chain that exhibits an affinity for inorganic particles. For example, 90/90/methyl methacrylate and butyl acrylate
For use with syrups of 10 W/W copolymer in methyl methacrylate, a suitable dispersant is a 95/5 W/W copolymer of methyl methacrylate and methacrylic acid or its metal salt. Other comonomers which are polar and exhibit an affinity for inorganic particles, such as dimethylaminoethyl methacrylate and quaternary ions or their acid salts, methacrylamide, γ-methacryloxypropyltrimethoxysilane, glycidyl methacrylate and p- Adducts with aromatic acids substituted with polar groups, such as aminobenzoic acid, and glycidyl methacrylate with γ-
Adducts with aminopropyltrimethoxysilane are also useful as polymeric dispersants. Another type of polymeric dispersant that is useful is a copolymer consisting of a relatively insoluble polymer chain and solvating polymer chains attached at irregular intervals along the insoluble polymer chain. It is a copolymer in which groups capable of anchoring to inorganic particles are bonded at irregular intervals to the polymer chains of Such copolymeric dispersants can be prepared, for example, by the methods described in British Patent Nos. 1,052,241 and 1,122,397. Particularly suitable for use in molding compositions for producing moldings consisting of unsaturated oligomers or case matrices obtained by polymerization, chain extension or crosslinking of solutions of unsaturated oligomers and unsaturated monomers. Examples of polymeric dispersants are oligomers of similar molecular weight having at least one like unsaturated group and at least one pendant polar side group. For example, in the case of a solution of an epoxy resin (e.g., sold under the trade name "Derakane") in styrene, which reacts with methacrylic acid at its two ends to form a divinyl-based unsaturated polymer. Suitable polymeric dispersants for use are those which react with methacrylic acid at one end to form a terminal unsaturated group and which react with p-aminobenzoic acid or γ at the other end.
- Oligomers that react with aminopropyltrimethoxysilane to produce terminal tethering groups that can be adsorbed onto the surface of inorganic particles (eg silica). A polymeric dispersant described as being particularly suitable for one type of polymerizable organic liquid is not necessarily limited to use with only that type. This is merely a possible case. Therefore, the above-mentioned dispersants containing terminal unsaturated groups as tethering groups may equally be used in molding compositions based on simple methyl methacrylate monomers. Suitable polymeric dispersants for use when the matrix polymer formed by the polymerization is a polyurethane derived from a polyol and a polyisocyanate are those in which the polyol portion of the polymerizable organic liquid is replaced by an acrylic polymer containing polar substituents. It is a gractopolymer obtained by grafting onto a polymer skeleton. A suitable dispersant for use in the case of epoxy resin based organic monomer liquids is a polymer obtained by reacting p-nitrobenzoic acid with some of the epoxy groups of the epoxy resin. Vinylidene-terminated urethane-based organic monomer liquids In the case of polymeric dispersants, the urethane has free NCO
It is a polymer that can be formed by reacting with γ-aminopropyltrimethoxysilane via a group. In most cases, the polymeric dispersant (C) will be a material that is manufactured separately and then incorporated into the molding composition separately, but this need not be the case.
Certain components of the polymerizable organic liquid (A) itself may act as polymeric dispersants (C). For example, a chain terminal carboxylic acid group of an unsaturated polyester used as a polymerizable organic liquid can be adsorbed onto the surface of an inorganic particle to become a tethering group.
Polymer chains terminated with monocarboxylic acid groups act as polymeric dispersants, whereas polymer chains terminated with dicarboxylic acid groups may act as flocculants, so such chains should be avoided. It is preferable. Polymeric dispersants made of polyesters which are substantially free of such dicarboxylic acid group-terminated chains but which contain a significant amount of monocarboxylic acid group-terminated chains are described, for example, in British Patent No. 1045199 and As described in US Pat. No. 1,317,605, polyesters can be prepared by using excess diol to create a low acid number polyester and then further reducing its acidic portion by reaction with a monoepoxide. Similarly, polymeric dispersants are
It can also be formed in situ during the process of dispersing the inorganic filler into the polymerizable organic liquid. That is, a low molecular weight substance capable of binding to the polymer to be solvated and containing a group potentially acting as a tethering group is pre-blended in the liquid.
For example, a solvable polymer containing epoxide groups is placed in a polymerizable organic liquid during the dispersion process of the inorganic filler, and is bonded to the carboxyl groups of nitrobenzoic acid in this liquid to form a polymer. A dispersant may be formed. The proportion of the polymeric dispersant (C) used in the present invention varies widely depending on the type of anchoring group in the dispersant, the selected inorganic filler material, the particle surface area and particle concentration, and the type of polymerizable organic liquid. Although variable, a generally acceptable lower limit for proportions is 0.01 g/m ² of the total surface area of the particles as determined by the BET nitrogen adsorption method. The proportion of the polymeric dispersant may have some suitable lower limit in order to ensure that the inorganic particles do not aggregate in the molding composition and maintain their non-agglomerated state during curing of the composition. is necessary. Generally, higher concentrations of polymeric dispersants are required when the concentration and total surface area of the inorganic particles are high or when the polymerizable organic liquid includes preformed soluble oligomers or polymers. Above a certain optimum concentration, increasing the proportion of the polymeric dispersant does not provide any particular advantage in stabilizing the dispersion of the inorganic particles. When the molding composition used in the present invention contains two or more types of fine particulate materials as an inorganic filler, or when a pigment as described below is present in addition to the inorganic filler, two or more types of fine particulate materials may be used as an inorganic filler. It is advantageous to use different types of polymeric dispersants. The "anchoring" component in these dispersants can be selected separately depending on the surface characteristics of the inorganic particles. The solvable components in these polymeric dispersants may be the same or different, but if they are different, they are miscible with each other and with other components in the composition, as described above. There must be. Although not essential to obtaining the advantages of the present invention, the molding composition used in the present invention contains, in addition to a polymerizable organic liquid (A), a particulate inorganic filler (B), and a polymeric dispersant (C). It is preferable to contain substances which provide active groups which allow very strong bonding between the polymer matrix and the inorganic particles in the final composite obtained after curing. Some degree of bonding between the polymer matrix and the inorganic particles always occurs even in the presence of a polymeric dispersant. This is because the properties of the polymeric dispersant cause it to exist at the interface between the polymer matrix phase and the inorganic particles and exhibit affinity for both of these phases. however,
In order to obtain composite molded articles with optimal mechanical properties from a molding composition, the strength of the bond between the polymer matrix and the inorganic particles must be at least as low as the internal cohesive strength of these two components. It needs to be as large as the other person. If appropriate, the required strong bond between the polymer matrix and the inorganic particles can be obtained by the use of suitably selected polymeric dispersants. That is, the use of a suitable polymeric dispersant ensures that the forces that engage the dispersant with the inorganic particles are sufficiently strong that the solvated components of the dispersant are chemically interacted with in the cured polymer matrix. A strong bond is obtained because it is sufficiently bound by action or because the solvate component is a miscible polymer with a molecular weight comparable to that of the matrix polymer. However, the very strong bond between the polymer matrix and the inorganic particles is such that at least one group (i) capable of bonding with a group in the substance of the inorganic particles is copolymerized or grafted with the matrix polymer of the final molded composite. This is preferably achieved or facilitated by the incorporation into the molding composition of a low molecular weight binder (D) of the type containing at least one group (ii) which can be When using this type of low molecular weight binder (D) that acts at the interface between the inorganic particles and the monomer liquid,
Care must be taken that the low molecular weight binder, like the polymeric dispersant (C), is present at the interface of the two components to be bound together, namely the monomeric liquid phase and the inorganic particles. To this end, the proportions of the polymeric dispersant (C) and the low molecular weight binder (D) used must be adjusted separately so that neither completely covers the inorganic particle surface, and mutually. It is necessary to adjust so that there is room for the other to be attached to the surface. The particular type of low molecular weight binder (D) used will depend on the type of inorganic filler (B) and polymerizable organic liquid (A). In general, suitable low molecular weight binders are materials that contain groups that can form multiple ionic, covalent or hydrogen bonds with the inorganic particles and groups that can react to form bonds with the polymeric matrix. Suitable groups for bonding to hydroxyl groups of inorganic particles, metal oxide substances or inorganic particles with a siliceous surface are, for example, oligomeric hydrolysis products of alkoxysilanes, chlorosilanes and alkyl titanates, or trivalent chromium complexes of organic acids. It is. When the surface of the inorganic particles is basic, for example in the case of alkaline earth metal carbonates or inorganic particles of metals such as aluminum, chromium and steel, suitable binding groups of the low molecular weight binder are carboxylic acid groups. . In the case of particles with acidic surfaces, such as kaolin particles, amine salt groups are suitable for low molecular weight binders as groups for binding inorganic particles. In the low molecular weight binder (D), groups suitable for bonding with the polymer matrix are those of the polymerizable organic liquid (A).
A typical example is a group that reacts with the polymer during its polymerization step. For example, low molecular weight binders containing ethylenically unsaturated groups are suitable for use as interfacial binders in addition polymerization systems containing vinyl groups, vinylidene groups, or similar unsaturated monomers. Low molecular weight binders containing amino, oxirane or carboxyl groups are suitable for use when the polymerizable organic liquid is an epoxy group-containing compound. Examples of low molecular weight binders that act at the interface of suitable inorganic particles include: - γ-methacryloxypropyl trimethoxy silane, γ-aminopropyl trimethoxy silane, γ-glycidyloxy propyl silane. Trimethoxysilane, vinyl triethoxysilane, vinyl triacetoxysilane, vinyl trichlorosilane, acrylic acid and methacrylic acid, and their metal salts, methacrylate chromic chloride, maleimide propionic acid, succinimide propionic acid , 4-aminomethyl piperidine, tetraisopropyl titanate, and tetrabutyl titanate The amounts of low molecular weight binders used in this invention are generally those commonly used in the art of reinforcing polymeric materials with inorganic fillers. It is quantity. In most cases, the lower limit of the suitable amount of low molecular weight binder used is about 0.001 g of binder per ^square meter of filler particle surface area. If desired, two or more low molecular weight binders of the type described above can be mixed. A dye or pigment can be added to the molding composition used in the present invention. These color components can be dissolved or dispersed in an intimate mixture of polymerizable organic liquid, inorganic filler, and polymeric dispersant. In the case of pigments, they can also be prepared by dispersing the pigments with the aid of suitable pigment dispersants, such as those of the type described in GB 1108261 or GB 9494/71. They can be incorporated into molding compositions as ready-made pigment dispersions dispersed in polymerizable organic liquids. Furthermore, the molding composition used in the present invention contains coarse filler particles or coarse fibrous substances that can be dispersed in the various components constituting the composition, but are not stably dispersed. You can also do that. By "coarse" we mean that the average diameter of the coarse granules or fiber strands is at least 10 mm larger than the average diameter of the inorganic filler fine particles (B) as defined above.
It means twice as big. In the presence of such coarse particles, a stable dispersion of fine inorganic filler particles behaves as if it were a liquid with respect to the coarse particles. That is, the resistance of the liquid to the movement of coarse particles throughout the interior of a dispersion of inorganic fine particles is 1, which has a viscosity and density equal to that of the liquid.
The same is true for the resistance to coarse particles inside a pure liquid. Even though the molding composition used in the present invention contains coarse particles, in the composite material obtained by polymerization and curing thereof, the formed polymer cooperates with the fine particles of the inorganic filler to mechanically remove the coarse particles. It essentially forms a binder that exhibits a high binding effect. Since there is no interaction between the coarse particles and the inorganic filler fine particles, the ratio of the inorganic filler fine particles to the polymerizable organic liquid does not need to be changed as it would be if no coarse particles were present. Polymerizable organic liquid (A) and inorganic filler suitable for use in the method for producing the molding composition used in the present invention
(B) and the polymeric dispersant (C) are as described above. The polymerizable organic liquid (A) may contain preformed polymers, dissolved or dispersed, if desired, and the latter polymers may be the same or different from the polymers resulting from the polymerization of the liquid (A) itself. Good things will be understood. It will also be understood that in addition to the polymeric dispersant (C), a low molecular weight interfacial binder (D) as described above may be included. The inorganic filler particles (B) can be dispersed in the polymerizable organic liquid (A) using any technique commonly used in the paint industry to create dispersions of pigments in liquid vehicles. If so, it can be carried out at a temperature above room temperature. For example, if the filler (B) is already available with the required primary particle size, the dispersion method involves dispersing the filler particles in the organic liquid (A) and applying a shear force to the dispersion to make the particles beads that break up the aggregates and wet them with an organic liquid.
Conveniently, the filler particles are dispersed in the organic liquid using milling, kneading or other means. Alternatively, the coarse inorganic filler particles can be directly pulverized (pulverized) in the presence of the polymerizable organic liquid (A) or its liquid component and in the presence of the polymeric dispersant (C). ) can also form fine particles. Such milling methods allow readily available materials such as coarse sand, such as those used in glass manufacture, to be utilized as inorganic fillers and reduce the problems and hazards of handling fine powders, such as explosion or silicosis. This reduces the need or degree of drying required with normal manufacturing processes of milling in aqueous media. Even more surprisingly, the composite material obtained by curing the molding composition produced by a special method of micronizing the inorganic filler directly in the polymerizable organic liquid (A). pre-milling of the inorganic filler in an aqueous medium, when a low molecular weight binder (D) of the type described above is incorporated and present during the milling step;
It has been found that the composites have superior properties compared to composites made from molding compositions containing the same inorganic filler particles, which are then typically obtained by drying at 100°C. The advantages of this are that (1) the initial amount of chemisorbed water concomitantly introduced by using coarse inorganic particles is relatively small; (2) the newly created inorganic particle surface is free from water or other small Polymeric dispersants reduce the possibility of contamination by molecules
This is due to the improved opportunity for (C) and the low molecular weight binder (D) (if present) to be strongly adsorbed by the inorganic particle surface. However, if desired, comminution of the inorganic filler material may be carried out in a suitable non-aqueous liquid other than the polymerizable organic liquid (A), followed by drying and removing the non-aqueous liquid and then converting the inorganic particles into organic particles. It can also be redispersed in liquid (A). Finely pulverizing an inorganic filler material with a coarse particle size of 100 to several thousand microns to form smaller particles requires a grinding object (preferably spherical or cylindrical) that is harder and denser than the filler material used. Using a conventional ball mill, stirred ball mill ( This is easily done using a grinder) or a vibrating mill. In order to obtain a very fine particle size or a special particle size distribution in the inorganic filler particles, it is necessary to carry out multistage grinding using grinding objects of different sizes, or to use a combination of grinding objects of different sizes. obtain. When a low-molecular-weight interfacial binder (D) is added to the molding composition used in the present invention, this is done in the step of redispersing the inorganic particles in the polymerizable organic liquid (A), or if necessary, inorganic It can be introduced during or after the step of forming the particles by milling. This binder
Although (D) can simply be introduced into the dispersion of inorganic particles, it is preferred that the binder (D) is bound to the inorganic particles by some means. For example, if the binder (D) is a silane derivative as described above, sufficient water should be present in the system or added to the system to completely hydrolyze the silane derivative. Advantageously, this hydrolysis can be accelerated by heating and addition of suitable catalysts such as N-alkylamines or dialkyltin dicarboxylates. The molding composition used in the present invention exhibits excellent storage stability and is easily redispersed even if it settles. If it is desired to prevent settling, bentonite clay, humidified
Silica, hydrogenated castor oil or other substances may be added. The molding composition used in the present invention has the advantageous property that it can be completely polymerized and cured. Multi-component composite molded articles made of polymer matrices can be produced.
A composite molded article can also be produced by curing a mixture of two or more of the compositions. As mentioned above, the molding composition used in the present invention has a special feature of maintaining an extremely low viscosity and good fluidity despite containing a fine particulate inorganic filler at a high solid volume concentration. For example, compositions containing 50 and 55% by volume of inorganic filler microparticles may also have a viscosity of the polymerizable organic liquid itself.
It only shows 10 and 100 times higher relative viscosities. Such a degree of relative viscosity is approximately close to the minimum value obtained for non-agglomerated, monodisperse spherical particles (J.Applied Polym.Sci., 15, 2007-2021
(1971)). For example, when a monomer such as methyl methacrylate with a viscosity of 0.5 centipoise is used as the organic liquid (A), 50% by volume of the inorganic filler fine particles
has a viscosity of 5 centipoise and 55 centipoise.
% by volume has a viscosity of only 50 centipoise. When using a resin/monomer mixed system with a viscosity of 5 poise as the organic liquid (A),
For dispersions with filler concentrations of 50 and 55% by volume,
They exhibit viscosities of only 50 and 500 poise, respectively. The molding composition used in the present invention has a low viscosity even at very low shear rates, that is, the composition has Newtonian flow or near-Newtonian flow properties at low shear rates, and is characterized by the presence of coagulated or agglomerated fillers. Another feature of this composition is that it does not have the thixotropy that occurs when the composition is thixotropic. may be slightly thixotropic).
Furthermore, because the inorganic filler has a fine particle size, its particles have little tendency to settle even in low-viscosity media during the molding and curing process, and when shearing force is applied to the composition, There is no tendency for dilational cavitation to cause cavitation. When molding the molding composition used in the present invention, in most cases of commonly used molding methods, the composition is molded under the temperature and shear conditions at which it is molded.
It is preferable to have a viscosity of poise or less. However, viscosities higher than this limit are acceptable for certain applications. On the other hand, when using a low pressure molding method, it is desirable that the viscosity of the composition does not exceed 100 poise. In general, various parameters such as the viscosity of the polymerizable organic liquid, the amount of filler, the size distribution of the filler particles, the performance and usage of the polymeric dispersant, etc., are adjusted to achieve a molding with an acceptable viscosity for a given molding technique. Adjustments to obtain compositions for use are readily available to those skilled in the art. Due to the above-mentioned characteristics, the molding composition used in the present invention can be molded by a molding method that could not be adopted in the case of conventionally known fine particle-filled compositions due to their high viscosity, often non-ideal viscosity. becomes possible. Furthermore, the presence of a high proportion of inorganic particles directly facilitates the casting of large moldings from the molding compositions used in the invention at atmospheric pressure or slightly above atmospheric pressure, and the polymerizable liquid facilitates the casting of large moldings during curing. The heat of polymerization generated is absorbed and dissipated by the filler material. This factor substantially reduces the chance of void formation due to boiling of the monomer and, if sufficient inorganic filler is present, the temperature increase during polymerization can be reduced even if there is no heat loss to the mold (this condition (which actually occurs in thick-walled molded products) does not exceed the boiling point of the monomer, completely eliminating the chance of void formation. However, if the "heat dissipation" ability of the composition is not sufficient to prevent boiling of the monomer, e.g., if premature polymerization is initiated at a temperature near the boiling point of the monomer, void formation may result in an increase in the curing process. This can be prevented by causing premature gelation of the composition by introducing a crosslinking reaction. In the case of compositions based on addition polymers this means ethylene glycol when the main component of the polymerizable liquid is methyl methacrylate.
This can be achieved by the presence of a polyfunctional compound containing a portion of a polymerizable liquid such as dimethacrylate. Alternatively, a separate gelling reaction can be introduced, such as reacting the polyisocyanate with an oligomer containing multiple hydroxyl groups present in the polymerizable liquid and curing is completed by free radical initiated addition polymerization. If desired, curing of the molding compositions used in the present invention can be carried out in closed molds at pressures above atmospheric pressure, in which case early curing involves boiling the monomers in the absence of crosslinking reactions. However, this requires expensive equipment and is disadvantageous in the case of very large molded parts. Various methods can be used to mold products from the molding composition used in the present invention. The composition can be easily molded by pouring the molding mixture into a mold and allowing polymerization to begin. Thus the sheet,
Rods, beams and other convenient moldings can be easily obtained. Initiation of polymerization can be effected by a thermally activated catalyst or, if curing at room temperature or lower temperatures is required, by addition of the catalyst just before shaping. A preferred variation of the simple casting method is to pour the raw molding composition into a closed matted mold under low pressure. This method requires pressures of less than 10 p.si, allowing the use of inexpensive lightweight molds and forming parts with extremely large surface areas, compared to the much larger surface areas of conventional filled compositions. High pressures are usually required. Another variation of this method is to fill the mold with fiber strands before injecting the dispersion into the mold so that the dispersion penetrates into the mesh of the fiber strands (“less-injection”). law). Again, only low pressures are required and high surface area moldings can be formed. Injecting the reactive resin into a closed mold filled with fiber strands provides additional benefits, such as avoiding the difficulties of molding fiber/resin dispersions, better reproducibility than in hand molding, and improved boss and It is also known to obtain the formation of two moldable good surfaces in ribs, etc., but this has not heretofore been carried out as a method for compositions with high filler content. Previously known filling compositions are either of too high a viscosity or contain coarse or agglomerated particles separated by a fiber mesh, both of which have high viscosity that prevents the mold from being filled. produces pressure. However, most of the molding compositions used in the present invention have very low viscosity and contain fine non-agglomerated particles, so they can pass through the fiber mesh and infiltrate the mesh. The fibers used in this method can be organic or inorganic (eg glass or metal) or mixtures thereof. The fibers are most conveniently introduced into the mold in the form of a mat, but loose chopped strands bound with a small amount of resin and spray-up preforms can also be used. In general, most of the fiber mesh has a diameter of 5 mm compared to the average particle size of the filler.
It should have pores that are twice as large, preferably 10 times larger. This condition is most easily met by using a fiber mesh formed from fiber strands with a thickness that is at least 5 times, preferably at least 10 times, the particle size of the filler for up to 40% volume fiber. will be achieved. Suitable fiber meshes of this type are commercially available; in the case of glass fibers, the meshes are obtained as multifibrillar strands containing 20 to 1000 10 micron fibrils per strand. Meshes formed from fibers having a diameter equal to or less than that of the filler particles can also be used, but only for smaller fiber volumes. Fiber-containing composites can also be produced by conventional methods such as hand molding and pressure molding of a mixture of the molding composition used in the present invention and chopped mixed fibers. Low viscosity is an advantage in this case as well, low molding pressures are used and wetting and defoaming are facilitated. Composite molded articles of the Sanderschich type can advantageously be produced by injection molding. For example, a core material, which can be a low-density foam, can be entirely encapsulated, and the combination of this core material with a high modulus, high strength composite sheath according to the invention creates a lightweight, extremely stiff and strong structure. is manufactured. This core material is placed in a mold, which is then sealed, and the molding composition used in the present invention is injected around it. Furthermore, the fiber mat can also be introduced into the mold together with the core material. The fiber mat helps position the core material in the mold and toughens the coating of the final molded part. Such a technique is described in the applicant's UK Patent Application No. 10551/72. Encapsulation of the core material is also carried out by casting the molding composition onto both sides of the core material before charging it into the mold, then sealing the mold and squeezing out excess liquid. You can also do that. Similarly, fiber mats can be placed on both sides of the core material before its introduction into the mold. Another type of Sandersch molding is one in which the molding composition is bonded to one side of a preformed sheet or shell during its curing process. For example, a shell molded body is vacuum thermoformed from a plastic sheet, a matted mold is placed behind it to form a sealed cavity, and a molding composition is injected into the cavity and cured. Thus,
A composite article is obtained in which the cured composite according to the invention is bonded to one side of the plastic. This method allows thin walled plastic moldings to be stiffened and strengthened while combining the simplicity of vacuum forming thermoplastics with the convenience and ease of low pressure injection of composites according to the invention. The molding compositions can also be rotomolded to give complex hollow molded parts and pipes. For this purpose, the molding composition is placed in a mold and the mold is rotated on one or more axes, depending on the complexity of the product, during which curing takes place. Also in this case,
Due to the absence of monomer boiling, easy defoaming and good flow properties of the molding composition, molded articles with large shapes and no defects can be easily produced. Furthermore, fibers can optionally be introduced into the mold. The cured molded articles as described above can be further processed by machining and bonding, if desired. Surprisingly, the cured composite according to the invention can be cured at temperatures above the glass transition point of the matrix polymer if it is amorphous and above its melting point when the polymer is crystalline. It can be thermoformed without damage and can be stretched to a large extent. For example, a heated sheet can be processed into a molded article by applying positive or negative pressure to it and drawing it. Conventional composites containing weakly bonded or condensed coarse particulate fillers usually cannot be thermoformed in this manner because they usually whiten and fail at low deformation rates. In all the above-mentioned molding processes, it is advantageous to use internal or external mold release agents to prevent the cured composite from sticking to the mold and to obtain a good surface finish. This technique is well known to those skilled in the art. Examples of internal mold release agents are alkali metal or alkaline earth metal salts of fatty acids and alkyl phosphates and their neutralized derivatives. Suitable external mold release agents are poly(tetrafluoroethylene), silicone and polyvinyl alcohol coatings on the mold. In the multi-component composite molded article obtained by curing the molding composition used in the present invention, the polymer matrix and inorganic filler particles therein are strongly bonded to each other, and the molding The product has unexpectedly excellent mechanical and physical properties. The reason for this is that the hardness and strength continue to increase as the content of the inorganic filler particles blended is increased to the maximum mentioned above. In addition, the molded article retains the original impact strength of the matrix polymer therein to a large extent, and its impact strength may be enhanced in some cases. When using particles with high Mohs hardness, such as quartz and alumina, the cured composites have very good wear resistance. Additionally, composites are substantially more fire resistant than unfilled polymers, and even when they burn, they contribute less to fires and have lower fire sizes and propagation speeds. Composites with particularly high fire resistance can be obtained by using fine fillers, such as aluminum oxide trihydrate and calcium sulfate hemihydrate, which wholly or partially contain the water of hydration that is released on heating. can. Products in which such coarse fibers are incorporated into composite materials are significantly toughened. The use of coarse granular ingredients
Composites with inorganic content in excess of 95% W/W can be formed, and although the strength is less than that of unmodified matrix polymers, the composites are significantly stronger and more wear resistant than conventional water hardening cements. . As is clear from the range of mechanical properties and possible processing methods mentioned above, the composites according to the invention are suitable for a very wide range of applications. Articles that take advantage of the good surface finish, abrasion resistance, ease of pigmentation and fire resistance that can be achieved include workpiece surfaces, decorative wall tiles, cabinet furniture, temporary tables and sanitary ware. Examples of articles that take advantage of the high stiffness and strength of composite materials and the ease of fabrication of large, thin-walled shell-shaped molded products using the "less-in-jet extension" method include automobile bodies, baths, boats, and shells. Articles that can be manufactured by rotational molding include pipes, silos, car bodies,
These include toys and storage tanks. Next, the present invention will be further explained with reference to Examples, in which the figures and percentages are by weight unless otherwise specified. The molding composition is molded into a sheet approximately 5 mm thick by casting, unless otherwise specified. The flexural modulus and strength of the molded products are determined by a three-point bending test (beam length is 10.16 cm and bending speed is 5 mm/min) at 25°C. All impact strengths are measured at 25°C using a Charpy impact tester as described in BS2782: Part 3, Method 306D (1970). Abrasion resistance is measured in each test with a taper abrasion tester (Taber Instrument) using a CS10 disk and a load of 1000 g for 1000 cycles. In this case the sample is weighed before and after the test and the weight loss per 1000 cycles is recorded. Particle size distribution is determined by the well known Coulter counter method. Example 1 This example uses an acrylic copolymer containing a quaternary ammonium group that anchors to the surface of silica particles as a polymeric dispersant to mold a fluid dispersion liquid from methyl methacrylate and quartz silica. It relates to manufacturing and shaping compositions. The quartz silica used has a surface area of 5.0 m ² /g as measured by the nitrogen adsorption method and the following particle size distribution: Countable particles of 10 microns or less
99.999% (97.5% by weight) Particles of 50 microns or smaller, calculated by number
Dry milled and air classified fine quartz silica (Minusil5 from Pennsylvania Glass Sand) with 99.999% (total 100.00% by weight)
It is. Gel permeation chromatography (GPC)
A copolymeric dispersant with a molecular weight of 20,000 W as measured by methyl methacrylate (81.4
9.6 parts of ethyl acrylate and 4.8 parts of dimethylamino-ethyl methacrylate quaternized with 4.2 parts of benzyl chloride). , and r-methacryloxypropyl trimethoxysilane as a low molecular weight binder.
with the presence of 1.8% by weight (based on silica)
The above silica was mixed with the monomer methyl methacrylate (containing 100 ppm of the polymerization inhibitor “Topanol” A ^* ).
The proportion of silica in the whole mixture is 67% by weight.
%, it becomes an extremely fluid and non-agglomerated dispersion (Ford
The viscosity measured using a No. 4 cup was less than 15 seconds). This dispersion contains 67% by weight silica (50%
(equivalent to volume %). 100 parts by weight of this dispersion was used as a molding composition, which was heated to 100°C and then cooled to room temperature, and 0.6 parts by weight of the polymerization initiator of trade name "Perkadox" Y16 was added.
(2% based on monomer) was added. The dispersion that has started polymerization is poured into a flat mold lined with a film under the trade name Melinex, and heated at 50℃ for 2 hours and 80℃ for 2 hours to polymerize and harden (cure).
I let it happen. The thus obtained sheet of cast-molded product is extremely glossy, has no surface scratches, contains silica in an amount corresponding to 50% by volume, and has a density of 12.6 GN/m ²
flexural modulus of elasticity, flexural strength of 110MN/ ^m2 and
Shape impact strength of 6.0KJ/ ^m2 (without notch)
It had However, in the above, "Topanol" A is 2,4-
Dimethyl-6-tert-butylphenol is a registered trademark of ICI. "Perkadox" Y16 is a registered trademark of AKZO-Novadel for bis(4-tert-butylcyclohexyl) peroxydicarbonate. "Melinex" is a registered trademark of ICI Corporation for biaxially oriented poly(ethylene terephthalate) sheets. Example 2 Example 1 was similarly repeated with increasing proportion of silica. That is, repeating the same ingredients as in Example 1, but with less methyl methacrylate, produced a dispersion containing 69% silica by weight with a measured viscosity of 19 seconds at 20°C (using a Ford No. 4 cup). I got it. When this was polymerized and cured in the same manner as in Example 1, a scratch-free, glossy sheet-like molded product containing 52.5% by volume of silica, having a flexural modulus of 12.4 GN/m ² and a flexural strength of 110 MN/m ² I got it. Example 3 Example 2 was repeated omitting the silane derivative.
A flowable dispersion with a Ford No. 4 cup viscosity of 16 seconds at 20° C. was obtained, which was cured as in Example 1 to give an unblemished 52.5% silica volume slightly weaker and more brittle than in Example 2. A glossy sheet was obtained. Example 4 In this example, the polymeric dispersants of Examples 1-3 were replaced with different acrylic copolymers in which carboxylic acid groups were present for anchoring to the silica particles. Instead of the dispersant used in Example 1, w(GP
Example 1 was repeated using 3.4 parts of a copolymer dispersant (according to C) 110,000 (98 parts methyl methacrylate, 2 parts methacrylic acid) based on silica to obtain a flowable dispersion. The final cast product was glossy, free of scratches, and had a flexural modulus of 10.4 GN/ ^m2 .
It had a bending strength of 127 MN/m ² and a Charpy impact strength of 6.5 KJ/m ² . Comparative Examples A-F To illustrate the importance of the presence of a polymeric dispersant, the same quartz silica concentrations as above were used, but the polymeric dispersant was omitted or a conventional dispersant was used instead. The production of various compositions using Comparative Example A When the same quartz silica (67 parts) as in Example 1 was sheared in 33% methyl methacrylate, a powder cake with no flowability was obtained. Comparative Example B The quartz silica (67%) described in Example 1 was sheared in a mixture of 31.2% methyl methacrylate and 1.14% gamma-methacryloxypropyltrimethoxysilane. A very thick agglomerated mixture is obtained,
This could not be cast. When this was pressurized and charged into a mold and cured in the same manner as in Example 1, a sheet with cracks and scratches was obtained. Comparative Example C The quartz silica (67%) described in Example 1 was sheared in a mixture of 30 parts of methyl methacrylate, 1.14% of gamma-methacryloxypropyltrimethoxysilane and 1.2% of sodium stearate. A thick agglomerated mixture was obtained which could not be cast, and when it was pressurized into a mold and cured as in Example 1, a cast product with cracks and scratches was obtained. Comparative Example D Comparative Example C using nonylphenol/ethylene oxide condensate instead of sodium stearate
was repeated. A cohesive mixture was obtained, which gave a cast with cracks and scratches. Comparative Example E Comparative Example C was repeated using cetylpyridinium bromide in place of sodium stearate. A cohesive mixture was obtained, which gave a cast with cracks and scratches. Comparative Example F To illustrate the superior mechanical properties of the filling compositions described in Examples 1-4 compared to the matrix polymers, the methyl methacrylate used in Example 1 was polymerized under the same conditions. The obtained polymer is
It had a flexural modulus of 3.0 GN/m ² , a flexural strength of 100 MN/m ² and an impact strength of 6-8 KJ/m ² . Examples 5-11 In these examples, dispersions of fine alpha-quartz silica were prepared by milling coarse glass-forming silica sand in monomer. Example 5 Coarse glass-forming silica sand (Harrison Meyer 44431) 312 with 80-86% particle size of 150-420 microns
g, methyl methacrylate 133 g, γ-methylacryloxypropyltrimethoxysilane 0.45 g
(0.15% based on silica) and copolymer dispersant (methyl methacrylate/methacrylic acid 98:2 copolymer with w of 110000 by GPC) 2.8 g
was charged into a 2 gallon ball mill along with 1050 g of 3/8 inch steatite balls. This charge-to-ball void ratio is 1/1. The mill was rotated at 60 rpm for 24 hours. After separating the balls, a dispersion containing 73% fine quartz silica in monomer is obtained, which has a Ford No. 4 cup viscosity of 58 seconds at 20°C and a shear rate of 0.4 poise at 25°C and a shear rate of 201/s. It had viscosity. The particle size distribution of the quartz thus obtained was as follows: Particles smaller than 10 microns, 99.7% by number (55.0
%) Particles smaller than 50 microns, depending on number 99.7%
(100.0%) The surface area of silica sand after pulverization is approximately 2 m ² /g,
The surface area before milling is less than 0.10 m ² /g. Methyl methacrylate was added to 173.7 g of this dispersion.
15.3 g and 1.18 g of Perkadox Y16 initiator (2% based on total monomer) were added. The dispersion was then cast and cured in the same manner as in Example 1. 67% silica
A glossy, intact sheet was obtained containing (50% by volume), the mechanical properties of which are shown in the table below. Example 6 The milling process described in Example 5 was repeated without using the silane derivative. A flowable dispersion of 73% colloidal fine silica in methyl methacrylate with a viscosity and particle size range similar to the dispersion of Example 5 was thus obtained. To 173.3 g of this dispersion was added 15.3 g of methyl methacrylate and Perkadox Y16 initiator.
1.18g was added. The dispersion was then cast and cured in the same manner as in Example 1. 67% silica (50% by volume)
A glossy, intact sheet was obtained containing the following properties, the mechanical properties of which are shown in Table 1. Comparative Example G The milling process described in Example 6 was repeated without the use of a copolymer stabilizer, resulting in an agglomerated mixture that could not be separated from the steatite milling media. Example 7 173.3 g of the dispersion described in Example 6, 15.3 g of methyl methacrylate, 1.18 g of Perkadox Y16 initiator
and 019 g of gamma-methacryloxypropyltrimethoxysilane (0.15% based on silica). This dispersion was left to stand for 24 hours, and then Example 1
and cured to give a glossy, intact sheet containing 50% by volume of silica with the mechanical properties shown in Table 1. Example 8 Example 7 was repeated except that the dispersion was heated to 100° C. for 5 minutes in the presence of the silane derivative before addition of the initiator and then cooled to room temperature and cured. Thus, silica 50 with the mechanical properties shown in Table
A glossy, intact sheet containing % by volume was obtained. Example 9 Example 7 was repeated with the addition of an additional 0.050 g of n-propylamine. The mechanical properties of the cured product are shown in Table 1. Example 10 1560 g of coarse silica sand described in Example 5, 600 g of distilled water
g and 1.2 g of sodium hydroxide were charged to a 1 gallon ball mill along with 5300 g of 3/8 inch steatite balls. The ball mill was rotated for 24 hours in the same manner as in Example 5, and after separating the balls from the charge, a fluid dispersion of fine silica sand in water was obtained. The silica had a similar particle size as in Example 5 after milling. The dispersion was then treated with 0.15% gamma-methacryloxypropyltrimethoxysilane (based on silica sand) as a 5% aqueous solution whose pH was adjusted to 3.5 with acetic acid. This dispersion was air-dried overnight and then
It was dried in an oven at 185°C for 2 hours. To 312 g of the dry silanized silica thus obtained were added 149 g of methyl methacrylate monomer and 2.8 g of the copolymer dispersant described in Example 5. The dispersion was sheared for 1 hour to redisperse the particles and yield a stable flowable dispersion. This dispersion was then polymerized as in Example 1, cast and cured to give a flawless sheet containing 50% by volume of silica with the mechanical properties shown in Table 1. Example 11 Example 5 was repeated using γ-aminopropyltrimethoxysilane in place of γ-methacryloxypropyltrimethoxysilane. The mechanical properties of the cast product obtained are shown in Table 1.

[Table] In the table, the results of Example 5 show the effect of adding an interfacial binder together with a polymeric dispersant during the milling process, and the effect of simply adding it after milling (Example 7) or This will be explained in comparison with the case where aqueous finely ground silica is pretreated (Example 10). Examples 8 and 9 illustrate the benefits of heating and catalytic treatment to enhance interfacial binder utilization. The relatively poor properties of the product of Example 11 demonstrate the importance of selecting an interfacial binder that can react with the polymer matrix, and Example 6 shows that similar results can be obtained by omitting the addition of binder. shows. Comparative Example H-1 These examples illustrate the importance of using fine particles of inorganic filler. Comparative Example H Coarse silica sand of Example 5 (average particle size 250 microns)
was mixed with methyl methacrylate, a silane derivative, and a polymeric stabilizer as described in Example 5 to obtain a slurry containing 67% silica that precipitated so rapidly that it was impossible to cast. To obtain a comparative sample, silica sand was slurried with the silane derivative and polymeric dispersant described in Example 5 in a syrup of 7.8 parts poly(methyl methacrylate) and 512 parts methyl methacrylate. The syrup slurry thus obtained
The mixture was heated to 100° C. for 5 minutes, cooled, and then polymerization was started in the same manner as in Example 1, followed by casting. The mold was rotated during curing to prevent settling. The cast product thus obtained had a rough surface due to the presence of coarse silica particles. The mechanical properties of this product are shown in Table 1. Comparative Example 1 A ball mill was filled with coarse silica sand, monomers and other ingredients as described in Example 5. However, if this mixture is
Milled for only 2 hours instead of hours. A slurry was thus obtained containing particles with the following particle size distribution: Particles smaller than 10 microns, 98% by number (7% by weight) Particles smaller than 50 microns, 98% by number (29%) Particles smaller than 100 microns, 98% by number (29%) Particles, 98% (55%) depending on number Particles smaller than 250 microns, 98% (96%) depending on number Particle surface area measured by nitrogen adsorption method is 0.16
m ² /g. This slurry settles too quickly for direct casting, so poly(methyl methacrylate) is added and the methyl methacrylate is evaporated to produce a handleable syrup with a polymer to monomer weight ratio of 1 to 6.6. I made it. Next, heat this syrup slurry to 100℃ for 5 minutes,
It was cooled to initiate polymerization, cast as in Example 1, and cured in a rotating mold to prevent settling. The resulting sheet had a rough surface due to the presence of coarse silica sand particles. The mechanical properties of this product are shown in Table 1.

[Table] The above results demonstrate that, in addition to the problems of processing coarse particle slurries, the use of coarse particles results in significantly inferior mechanical properties compared to the properties of the product of the invention as exemplified by Example 8. This indicates that a product with a certain amount of moisture can be obtained. Examples 12, 13 and 14 The method of Example 5 was repeated with the concentration of silane derivative increased to 1.5% based on silica. Methyl methacrylate concentration before curing The final silica concentration in the cast article is 50%, 55% and 60% by volume, respectively.
(67%, 72% and 78% by weight). The mechanical properties of the obtained cured product are shown in Table 1.

TABLE The above results demonstrate how the mechanical properties of the cured composite continue to increase with increasing particle volume. Additionally, the abrasion results show a 7x improvement compared to the base polymer. Comparative Example J A composite material containing 60% by volume of silica was produced by the method described in Examples 12 to 14 using a silane derivative but omitting the polymeric dispersant, resulting in castings with cracks and scratches. Goods were obtained. Example 15 Following the same pulverization method as in Example 5, the average particle size
200 micron coarse β-cristobal silica sand
2726.50g, methyl methacrylate (Topanol
A 2-gallon ball mill containing 9700 g of steatite balls was charged with 85 g of 903 (containing 100 ppm of A), 7.81 g of γ-methacryloxypropyltrimethoxysilane, and 57.89 g of methyl methacrylate/methacrylic acid 98:2 copolymer dispersant. . The mill was rotated at 60 rpm for 20 hours and then 254.32 g of rutile titanium dioxide pigment was added. The mill was run for an additional 4 hours and the resulting dispersion was separated from the balls. This flowable dispersion contained 77.8% by weight of cristobalite silica and pigment particles, and the particle size distribution after milling was as follows: Particles below 10 microns, 99% by number (70% by weight) 50 microns Particles smaller than or equal to 99% (99%) by number Particles smaller than or equal to 75 microns, 99% (100% by number) Perkadox Y16 initiator to 309 parts of this dispersion 1.18
9.64 parts of methyl methacrylate were then evaporated. The dispersion was poured into a stainless steel sheet mold coated with a mold release agent and then cured as in Example 1. A shiny, intact sheet containing 64% by volume (81% by weight) of silica and rutile particles was thus obtained. The mechanical properties of this product are flexural modulus 16.60GN/m ² and flexural strength
The impact strength was 139.7MN/m ² and the impact strength was 4.9KJ/m ² . Examples 16-17 In these examples, dispersions of inorganic fillers in polymerizable liquids are stabilized by in situ formation of calcium salts of acidic copolymer dispersants. Example 16 Coarse β-Cristobalite silica sand as described in Example 15
1333.5g, γ-methacryloxypropyltrimethoxysilane 3.82g, rutile titanium dioxide 120
g, 14.15 g of 25:1 molar ratio copolymer of methyl methacrylate and methacrylic acid, calcium oxide
A mixture of 0.36 g (1 molar equivalent based on the acid present in the copolymer dispersant) and 556.7 g of methyl methacrylate (containing 100 ppm of Topanol A) was charged to a 1 gallon ball mill along with 5200 g of steatite balls. The mill was rotated for 24 hours to obtain a dispersion containing 73% particles with a particle size distribution similar to that of Example 5. This dispersion had a Bruckfield viscosity of 0.8 poise at 2 r.pm 20°C. A similar dispersion obtained without using calcium oxide has a viscosity of 33 poise at 2 r.pm. 280 parts of the former dispersion, 24 parts of methyl methacrylate and
2.0 parts of Perkadox Y16 initiator was added. At this stage, the Bruckfield viscosity of the dispersion was 0.2 poise. This dispersion was cast in the same manner as in Example 1 and cured to give a glossy sheet containing 50% by volume of silica and rutile. Its mechanical properties were a flexural modulus of 10.55 GN/m ² , a flexural strength of 113 MN/m ² and an impact strength of 5 KJ/m ² . Example 17 280 parts of the ball-milled dispersion described in Example 15 were mixed with methyl methacrylate/butyl acrylate in methyl methacrylate monomer (weight ratio 90:
10) 22.32 parts of a 45% solution of the copolymer and a further 1.78 parts of methyl methacrylate monomer were added together with 1.8 parts of Perkadox Y16 initiator. At this stage, the Bruckfield viscosity of the dispersion was 53 poise at 20 rpm and 20°C. This dispersion was cast in the same manner as in Example 1 and cured to give a glossy sheet containing 50% by volume of silica and rutile. Its mechanical properties are flexural modulus
10.80GN/m ² , bending strength 112MN/m ² , impact strength
It was 5KJ/m ² . Example 18 Add the following ingredients to a 3/8 inch steatite ball.
A 25 gallon ball mill was charged containing 60% by volume: - Coarse Cristobal silica sand (as described in Example 15) 2609 parts methyl methacrylate (contains 100 ppm Topanol A) 1045 parts w50000 (by GPC) methyl methacrylate/dimethyl Aminoethyl methacrylate copolymer (weight ratio 95:5) 26.3 parts γ-methacryloxypropyltrimethoxysilane 7.1 parts Distilled water 1.5 parts The volume ratio of the charge to the void between the balls is 1/
It is 1. The mill was rotated at 60 rpm for 6 1/2 hours and a dispersion with a cristobalite particle size distribution similar to that of Example 5 was obtained in greater than 98% yield. This dispersion contained 70% (50% by volume) of fine cristobalite and had a Bruckfield viscosity of 0.05 poise at 2 r.pm and 20°C. When methyl methacrylate is slightly evaporated, it becomes 78% with a viscosity of 0.40 poise.
(55.6% by volume) dispersion was obtained. As an internal mold release agent in dispersions with a solids content of 70%
An alkanolamine neutralized fatty acid phosphate known as Zelec NE (du Pont) was added at 0.15% based on the dispersion and Perkadox Y16 at 2% based on methyl methacrylate. This dispersion was poured into a flat glass mold as in Example 1 and cured to yield a glossy, intact sheet containing 54% by volume of silica. Its mechanical properties are flexural modulus
12.1GN/m ² , bending strength 140MN/m ² , impact strength
It was 8.0KJ/ ^m2 . Example 19 A 1-quart mill was charged with the following ingredients: - 324 g coarse kaolin (“Molochite” 60-80 ^* ) with an average particle size of 200 microns calcined in a tunnel dryer 113 g Methyl methacrylate (containing 100 ppm Topanol A) γ-methacryloxypropyltrimethoxysilane 0.46g w100000 (according to GPC) methyl methacrylate/methacrylic acid (98:2) copolymer 2.8g 3/8 inch steatite balls 1050g Rotate this mill at 90rpm for 24 hours Let it be fine〓
A fluid dispersion containing 76.3% of calcined kaolin was obtained. The final particle size distribution of this dispersion was as follows: Particles smaller than 10 microns, 99.5% by number (70
%) Particles smaller than 50 microns, depending on the number 99.5% (93
%) Particles smaller than 75 microns, depending on the number 99.5% (97.5
%) Particles smaller than 100 microns, 99.5% depending on number
(100.0%) This dispersion was further diluted with methyl methacrylate, polymerization was initiated as in Example 1, and cured to yield a flawless sheet containing 50% by volume of inorganic particles.
Its mechanical properties were a flexural modulus of 13.6 GN/m ² , a flexural strength of 130 MN/m ² and an impact strength of 6.6 KJ/m ² . * “Molochite” is a mixture of 56% mullite and 44% amorphous silica.
It is a registered trademark of Clay Company. Example 20 A 1 gallon ball mill was charged with the following ingredients: - Coarse alumina trihydrate (80% BS sieve 300 or higher: bound water)
34%, free water 0%) 1452g γ-methacryloxypropyltrimethoxysilane 3.8g Copolymer dispersant described in Example 19 14.16g Methyl methacrylate (100ppm Topanol A)
556.84 g 3/8 inch steatite balls 5200 g The mill was run at 60 rpm for 10 hours to obtain a fine low viscosity dispersion in methyl methacrylate containing 72% alumina trihydrate. This dispersion was polymerized in the same manner as in Example 1, cast, and cured to give a glossy, intact sheet with mechanical properties of flexural modulus of 13.8 GN/m ² and flexural strength of 80.7 MN/m ² . Obtained. This sheet did not ignite when exposed to a Bunsen burner flame for 1 minute. Example 21 The method of Example 5 was repeated by charging the mill with the following ingredients: - Coarse β-Cristobal silica sand as described in Example 15
2478.6g Rutile titanium oxide pigment 223.00g Methyl methacrylate (100ppm Topanol A)
1045g γ-methacryloxypropyltrimethoxysilane 7.1g Copolymer dispersant described in Example 19 26.3g 3/8 inch steatite balls 9700g The mill was rotated for 24 hours and then heated at 20°C, 20r.p.
A dispersion in methyl methacrylate containing cristobalite and 73.5% rutile was obtained with a Bruckfield viscosity of 3.5 poise at m. The particle size distribution of this dispersion was as follows: Particles smaller than 10 microns, 99.7% by number (80.0
%) Particles smaller than 50 microns, depending on the number 99.7% (95.5
%) Particles smaller than 75 microns, 99.7% depending on number
(100.0%) This dispersion was further mixed with monomer at 20°C and 20rpm for 0.4%
The mixture was diluted to Poise's Bruckfield viscosity, and polymerization was initiated and cured in the same manner as in Example 1 to obtain a sheet containing 50% by volume of cristobalite and rutile. Its mechanical properties are flexural modulus of 10.6GN/m ² ,
The bending strength was 118.9 MN/m ² and the impact strength was 5.9 KJ/m ² . Example 22 Two of the dispersions described in Examples 20 and 21, respectively:
They were mixed at a weight ratio of 1:1, and then polymerization was initiated and cured in the same manner as in Example 1. The obtained cured cast product had mechanical properties of a flexural modulus of 12.4 GN/m ² and a flexural strength of 102 MN/m ² . 4 inches long and 1/2 wide formed from this composition
When one end of the inch rod was held in horizontal contact with a Bunsen burner flame for one minute, the composition ignited and burned with a small blue flame that self-extinguished within seconds. Example 23 To 1600 parts of the ball milled dispersion of Example 21 were added 43 parts of polyvinyl chloride particles (Corvic P65/50 ^* ) and then 43 parts of methyl methacrylate monomer were evaporated. As a result, polyvinyl chloride particles formed an organosol dispersion in methyl methacrylate monomer. This dispersion was cast as in Example 1 and cured to give a shiny, intact sheet containing 53.6% by volume of cristobalite and rutile in a matrix of polymethyl methacrylate and polyvinyl chloride. This product had similar mechanical properties and surface finish to the product described in Example 21. When subjected to the combustion test described in Example 22, the sample burned much more slowly than the Example 21 product. *Corvic P65/50 is a registered trademark of ICI Corporation for spray-dried emulsion-polyvinyl chloride. Example 24 This example illustrates the crosslinking action of accelerating the hardening of flowable compositions and inhibiting monomer boiling. 24.2 g of methyl methacrylate and ethylene glycol dimethacrylate were added to 321 g of the dispersion of Example 21.
6.0 g and 2.36 parts of Per Kadox Y16 were added.
The obtained dispersion was poured into a flat plate mold preheated in an 80°C furnace. After 6 1/2 minutes, the solid, intact cast was removed from the mold. The internal temperature of this molded product reached a maximum of 154°C, and its mechanical properties were a bending modulus of elasticity of 13 GN/m ² , a bending strength of 128 MN/m ² and an impact strength of 4.3 KJ/m ² . When the above method was repeated omitting the ethylene glycol dimethacrylate, a foamed cast article was obtained. Example 25 The method of Example 24 was repeated using a mold and furnace temperature of 90°C. A solid, flawless cast was removed from the mold after only 4 minutes. In this case the peak temperature is
The temperature reached 155℃. Example 26 This example illustrates the "heat dissipation" effect of inorganic particles to prevent monomer boiling during the curing process. The dispersion of Example 21 was cured so that the volume ratio of cristobalite and rutile contained in the composite material was 60%.
It was adjusted by removing some monomers so that Polymerization of this dispersion with 2% Perkadox Y16 based on the free methyl methacrylate present.
and then at 80°C as in Example 24.
Curing was performed with After 10 minutes, the solid cast sheet was removed from the mold. In contrast, cured under the same conditions
Sheets containing 50% filler by volume were defectively flawed and bubbly. Examples 27-30 These examples demonstrate that the type of initiator that can be used to cure the flowable composition and that variations in the initiator do not significantly affect the mechanical properties of the cured product. Example 24 was repeated using the initiators shown below. The results are shown below.

Table: Example 31 This example concerns the use of rotational molding.
300 g of the ball milled dispersion described in Example 21,
11.3 g of the dispersant described in Example 19, 5.5 g of ethylene glycol dimethacrylate, 8.7 g of methyl methacrylate, 1.6 parts of benzoyl peroxide and 1.6 parts of dimethyl para-toluidine were added. The Bruckfield viscosity of the dispersion thus obtained was 20°C and 20r.p.
m. was 40 poise. The dispersion was placed in a 1 pint polypropylene frustoconical sealed tub mold (12 cm top diameter, 11 cm base diameter, 12 cm length). The tab was rotated at room temperature at 70 rpm around the symmetry axis and 16.5 rpm around the tipping axis. 30
After a few minutes, a thin-walled molded part was obtained that corresponded exactly to the inner contour of the mold. Example 32 This example relates to the production of fiber-modified composites. The curable composition used had an initiator added.
Dispersion as described in Example 21 with a Bruckfield viscosity of 0.4 poise at 20 rpm and 20 DEG C., which upon casting gives a cured sheet containing 50% by volume of cristobalite and rutile. This dispersion was pumped using a peristaltic pump into a very low pressure head (10p.
si) and vertically held 3/16 inch thick flat sheet metal containing two layers of chopped strand fiberglass mat (“Supra E Mat” EPL436 ^* ) and two layers of fiberglass surface veil. It was charged to the bottom of the mold. Pumping continued until the dispersion flowed out of the top of the mold. The mold inlets and outlets were then tightened to seal the mold and the samples were cured in the mold at 50°C for 2 hours and then at 80°C for 2 hours. The resulting cured product was free of air and defects and contained 56% cristobalite and rutile and 15.6% glass fiber strands. Its mechanical properties were a flexural modulus of 12.5 GN/m ² , a flexural strength of 95.0 MN/m ² and an impact strength of 27.0 KJ/m ² . * “Supra E Mat” is approx. per strand
For chopped glass fiber strand mats bonded with polymer latex having 200 fibers (each fiber diameter is approximately 10 microns)
It is a registered trademark of Fiber Glass. Comparative Example K The slurry described in Comparative Example I containing particles larger than 100 microns was charged into a glass fiber filled mold under the conditions described in Example 32. The mold blocked very quickly and could not be further charged with slurry. Furthermore, the silica concentration in the slurry was lowered to 40% by volume, but the mold also became blocked in this case. Example 33 381 g of the dispersion described in Example 24 (50% by volume of cristobalite and rutile in cured product) were mixed with 2.5 g of benzoyl peroxide and 2.5 g of dimethyl para-toluidine.
Polymerization was initiated using This dispersion (20 r.p.m with a Bruckfield viscosity of less than 5 poise at 20°C) was then applied in one layer of a surface veil and a continuous strand glass fiber mat (EPL 455,
Each strand was placed into a tub mold as described in Example 31 lined with one layer of fibers (containing approximately 20 10 micron diameter fibers). Example 31 of this sealed mold
It was rotated for 1 hour at room temperature in the same manner as above. A thin, fiber-reinforced molded article was thus obtained that was completely infiltrated with fibers and exactly matched the contour of the mold. Example 34 A clear 1/32 inch thick sheet of oriented cast polymethyl methacrylate (Perspex, ICI) was placed against one side of a 3/16 inch thick cavity sheet mold. Two layers of chopped strand mat as described in Example 32 were placed into the mold and the mold faces were then closed. The dispersion of Example 32 was similarly pumped into this mold. 10 at room temperature
After curing for minutes and post-curing at 80° C., a high quality molded article 3/16 inch thick was obtained consisting of a glass fiber reinforced composite according to the invention bonded to an acrylic sheet. Its mechanical properties were as follows:

[Table] Example 35 The dispersion obtained by further modifying the dispersion of Example 21 by adding methyl methacrylate was used as Example 1.
A 3.3 mm sheet containing 30% by volume of cristobalite and rutile was obtained after casting and curing as described in . This sheet was heated to 180°C in an air oven and then
It was placed over a 10 cm hole and compressed air was applied to one side of the hole to form a 9 cm high blister without blowing into the composite material. The thickness of this blister at the top is approximately 0.2 mm. Example 36 A 3.3 mm thick sheet containing 50% by volume of cristobalite and rutile was cast from the dispersion described in Example 21. This sheet was heated to 180°C and blow molded in the same manner as in Example 35. A hemispherical thermoformed article with a height of 6 cm was formed without destruction of the composite material. Example 37 An unsaturated polyester resin containing monocarboxylic acid-terminated polymer chains that could act as a polymeric dispersant, but not dicarboxylic acid-terminated chains that would act as a flocculant, was prepared by condensation of the following components (with toluene). 26 parts of isophthalic acid (present as water-entraining agent) 32 parts of maleic anhydride 42 parts of propylene glycol Loss of glycol was prevented by the use of a short Vigreux column. The reaction continued until the acid value of the mixture decreased to 10 mg KOH/g, at which time 11.5 parts of the water produced was collected.
3.8 parts of “Cardura” EK was added to further reduce the chance of the presence of dicarboxylic acid terminal chains.
The reaction mixture was heated to about 230°C with an acid value of about 1.0 mgKOH/g.
It was held until it decreased to . At this time, about 1 out of every 20 chains now has an acid group at the end. The batch was then cooled to below 80°C, a vacuum was applied to remove as much toluene as possible, and the reaction mixture was diluted with styrene to a solids content of about 70% to give a viscosity of 13 poise, a hydroxyl value of about 25 mg KOH/g and a polyester. A non-volatile resin having a number average molecular weight of about 2000-3000 was obtained. Then add “Topanol” 354 ^** to this product.
was added at 0.02% based on solid resin. By charging the following ingredients into a clay mixer and mixing for 2 hours, the non-volatile content of polyentel is reduced to 50%.
A 50% by volume silica dispersion in a 5% styrene solution was prepared: 312 parts finely divided silica ("Minusil" 30 ^*** ) 68% styrene solution of the above polyester 89.3 parts styrene 33.9 parts γ-methacryloxypropyltrimethoxysilane 2.98 parts 1% styrene solution of hydroquinone 1.0 parts A low viscosity peptized dispersion containing 71% silica which is self-defoaming and self-expanding is thus obtained. Polymerization of this dispersion was initiated using 1.5% benzoyl peroxide based on the resin and styrene present. A high quality black was obtained after casting in a glass plate mold and curing for 1 hour at 80°C. Its viscosity and mechanical properties are shown in Table 1. *"Cardura" E is a registered trademark of Shell International for glycidyl esters of branched chain _C9 - _C13 saturated fatty acids with a typical epoxy value of 245. ** “Topanol” 354 is the ICI for 2,6-di-tert-butyl-4-methoxyphenol
It is a registered trademark of the company. *** "Minusil" 30 is a registered trademark of Pennsylvania Glass Sand Company for dry-ground, air-classified alpha-quartz silica with the following particle size distribution: 99.8% (52%) depending on the number of particles of 10 microns or less Particles of 50 microns or less (86%) Particles of 100 microns or less (100%) Example 38 The following ingredients were charged into a soil mixer and mixed for 2 hours. : Minusil30 312 parts Styrene solution of polyester described in Example 37
50 parts Styrene 65 parts γ-methacryloxypropyltrimethoxysilane 2.98 parts 1% hydroquinone solution in styrene 1.0 parts A low viscosity peptized dispersion containing 72% silica is thus obtained, which is cured as in Example 37. A high quality cast product was obtained. Its viscosity and mechanical properties are shown in Table 1. Example 39 The method of Example 38 was repeated without using the silane derivative. In this case too, a low viscosity dispersion and a high quality cast product were obtained. Its viscosity and mechanical properties are shown in Table 1. Comparative Examples L and M The method of Examples 37 and 38 was repeated but with similar composition.
Each was repeated using a polyester based on isophthalic acid with an acid value (non-volatile) of 25 mg KOH/g. The relatively high acid number of this polyester, which is a typical commercially available polyester, indicates that it contains a significant proportion of short dicarboxylic acid end chains that act more as a flocculant than as a dispersant. A dispersion containing 50% by volume of silica (Minusil 30) was obtained in each case. The significantly higher viscosity shown in the table for this dispersion clearly demonstrates that the dispersion is flocculated. Comparative Examples N-Q These examples describe the compositions described in Examples 37-39 and Comparative Example M without the use of silica filler. The curing conditions used were the same as in Example 37. The results are shown in Table 1.

[Table] From the results in Table 1, it is clear that low acid value polyesters, which are less likely to contain difunctional acid groups, give dispersions with much lower viscosity than high acid value polyesters. Upon curing, the flowable compositions of Examples 37, 38, and 39 form stronger composites than the matrix polymer. This effect is most pronounced for polyester compositions with 30% non-volatile content. This is because 30% non-volatile polyester without fillers will not even cure to a homogeneous solid. Example 40 This example and Examples 41-42 illustrate the use of matrix polymers derived from methyl methacrylate and bis(methacrylic acid) adducts of epoxy resins. A surface area of 3 m ² /g and a particle size distribution of: 99.9% (40
%) Particles smaller than 10 microns, depending on the number 99.9% (81
%) Particles smaller than 50 microns, depending on the number 99.9% (100
%) of 1640 parts of fine β-cristobalite silica,
120 parts of methyl methacrylate and 1004 parts of “Epikote”
(registered trademark for the condensation product of epichlorohydrin and diphenylolpropane with a molecular weight of approximately 1800) in methyl methacrylate of a bis(methacrylic acid) adduct of an epoxy resin known as
Add 40 parts of the dispersant solution described later in the mixture with 480 parts of the solution.
dispersed in the presence of The dispersion is carried out using a laboratory high-speed Torrance Cavitation Disperser, with the silica being added gradually while stirring the monomer/adduct mixture, and finally the disperser is turned to 1000 rpm. .pm
The operation was completed after running for 30 minutes. The viscosity of the fluid dispersion thus obtained was measured using a B-type viscometer and a multi-speed model RVF (Brookfield).
Engineering Laboratories). Perkadox Y16 initiator was dissolved in a portion of this dispersion at 2% based on monomer/adduct content, degassed under reduced pressure and then at 50°C for 2 hours and at 80°C for 2 hours.
It was time-molded into a sheet of composite containing 54% silica by volume. Its physical and mechanical properties are shown in Table 1. In the table, the viscosity is expressed in poise at 20°C. Two viscosity values (a) and (b) are shown for shear-thickening or shear-thinning compositions, where (a) was measured at 2 rpm using a type B spindle and (b) ) using the same spindle
Measured at 20rpm. For substantially Newtonian flow compositions, only one viscosity value is given, and this is the value measured at 2 rpm. The bis(methacrylic acid) adduct of the epoxy resin used in the above method was prepared by heating the following ingredients under reflux at 135-140°C for 1 1/2 hours: - “Epikote” 1004 720 parts Butyl acetate 500 parts Hydroquinone 0.1 part Dimethylaminoethanol 2 parts Methacrylic acid 70 parts Thus, 90% of the epoxy groups present in the epoxy resin were converted to ester groups by methacrylic acid (as confirmed by acid value measurement). The solvent was then removed under reduced pressure at 70°C and the residue was dissolved in methyl methacrylate to obtain a 50% solution. The dispersant solution used in the above method was prepared as follows. The preparation of the epoxy resin adduct described above was carried out by reducing the amount of methacrylic acid to 50 parts. 33 parts of P-nitrobenzoic acid and 1 part of dimethylaminoethanol were added to the resulting product without removing the solvent. This mixture was heated at 135-140°C under reflux for 2 hours.
Heated for 1/2 hour, then the solvent was removed under vacuum at 70°C. The dispersant formed was dissolved in methyl methacrylate to obtain a 50% solution. Comparative Example R The method of Example 40 was repeated without using the dispersant solution. Viscosity measurements of the resulting dispersion showed that it exhibited substantial shear thickening properties. The results are shown in Table 1. Example 41 The method of Example 40 was repeated by adding gamma-methacryloxypropyltrimethoxysilane and water to 2240 parts of the silica/monomer/adduct mixture just before the final step of dispersing the silica at 1000 rpm for 30 minutes. Repeat additions were made in the proportions of 4 parts and 1 part, respectively. The results are shown in Table 1.

[Table] The results shown in Table 1 demonstrate that there is a significant improvement in the fluidity of curable compositions obtained using polymeric dispersants and that incorporation of interfacial binders during the filler dispersion process improves fluidity. It is demonstrated that the properties are further improved. Example 42 The method of Example 40 was repeated using 1640 parts of fine silica, 120 parts of methyl methacrylate, and 50 parts of epoxy resin adduct.
% solution, 170 parts of the dispersant solution described below, and 1 part of water as raw materials. The resulting dispersions had viscosities of (a) 66 poise (spindle No. 3) and (b) 378 poise (spindle No. 6). The cured composite contains 54.0% silica by volume and has a flexural modulus of 15.1GN/
m ² , bending strength 154MN/m ² and impact strength 7.9KJ/m ²
It had The dispersant solution used in this method was obtained as follows. The method described in Example 40 for the production of epoxy resin adducts was repeated by changing the amount of methacrylic acid.
The number of copies was reduced to 50. γ in 50% solution of adduct
35 parts of -aminopropyltrimethoxysilane were added and the resulting mixture was allowed to stand overnight to complete the reaction between the residual epoxy groups of the adduct and the amino groups of the silane derivative. Example 43 This example describes a polymerization system based on styrene and chlorophenylmaleimide. 312 parts of chlorophenylmaleimide was dissolved in 208 parts of styrene with slight warming to obtain a comonomer mixture in a molar ratio of 1:3. Add to this 50% of the dispersant described below.
% solution were added followed by 1410 parts of finely divided silica as described in Example 40. Example of this silica
40, and 3.5 parts of γ-methacryloxypropyltrimethoxysilane and 0.7 parts of water were added just before the final dispersion step at 1000 rpm.
A fluid dispersion with a viscosity of 9 poise was thus obtained,
This was cured in the same manner as in Example 40 to obtain a composite sheet containing 53.7% by volume of silica. The dispersant solution used in this example was obtained as follows. To a mixture of 0.85 parts of butanol, 2.0 parts of glycidyl methacrylate, and 17.8 parts of hydroxyisopropyl methacrylate heated to 30°C, 2.55 parts of methacrylamide was added along with some water to aid dissolution. Then 13.2 parts of styrene, 2
- 20.1 parts of ethylhexyl acrylate and 0.5 parts of tertiary butyl perbenzoate were added. 42.2 parts of xylene was heated to reflux temperature (140°C), and the above-mentioned monomer mixture was fed thereto over 3 hours.
After a period of time, an additional 0.1 part of tertiary butyl perbenzoate was added. Heating at reflux temperature was continued until the solids content of the mixture was 49-51%. The mixture was then cooled to 110 DEG C. and 0.6 parts of P-aminobenzoic acid and 0.1 parts of "Armeen" DMCD (registered trademark for dimethylcocoamine) were added. Heating at reflux temperature was started again and continued until the mixture had an acid number of less than 0.5 mg KOH/g. The xylene was then removed by vacuum distillation and the remaining solid polymer was dissolved in styrene to obtain a 50% solution. Comparative Example S The method of Example 43 was repeated without using a dispersant solution. When only 32% by volume of silica was added, the dispersion became extremely thixotropic and could not be molded. Example 44 This example and Example 45 illustrate the use of a polymerization system based on methyl methacrylate copolymerized with the reaction product of hydroxyethyl methacrylate and melamine-formaldehyde resin. 180 parts of paraformaldehyde, 126 parts of melamine,
A mixture of 185 parts of n-butanol and 200 parts of water is 1/
The pH was adjusted to 9.0 using 2N sodium hydroxide solution and then heated under reflux for 30 minutes. To this mixture was added 780 parts of hydroxyethyl methacrylate (which contains enough free methacrylic acid to lower the PH of the mixture to 4.5), 0.5 parts of hydroquinone, and 200 parts of toluene. The resulting mixture was heated and water was removed by distillation using a Dean and Stark separator. During the 3-hour distillation, the temperature of the mixture increased from 88% to 120°C, resulting in an aqueous distillate of 314 c.c.
has been removed. The product was filtered to obtain a low viscosity syrup. Then fine silica 1210 described in Example 40
125 parts of the syrup, 375 parts of methyl methacrylate
Methyl methacrylate as described in Part and Example 18
A dispersion was prepared by the method described in Example 40 from 20 parts of the dimethylaminoethyl methacrylate copolymer dispersant. The properties of the highly fluid dispersion obtained and of the composite containing 48.0% by volume of silica formed by curing this dispersion are shown in Table 1. Example 45 The method of Example 44 was repeated with the addition of 5 parts of γ-methacryloxypropyltrimethoxysilane and 1.25 parts of water just before the final dispersion step for 30 minutes at 1000 rpm. The properties of the resulting dispersions and the composites formed therefrom are shown in Table 1. Comparative Example T The method of Example 44 was repeated without using the copolymer dispersant. The resulting dispersion rapidly became thixotropic during the addition of silica and could only incorporate 46.6% by volume of silica. The properties of this dispersion and the composite formed are shown in Table 1.

[Table] In this case as well, the above results show that by incorporating a polymeric dispersant and further an interfacial binder, the fluidity of the curable composition obtained and the properties of the composite material formed are significantly improved. It is recognized that Example 46 This example illustrates the use of a copolymer of methyl methacrylate and vinylidene terminated urethane prepolymer as the base for a polymer matrix. 400 parts of "Desmodur" N (registered trademark for trifunctional isocyanates) are dissolved in 686 parts by volume of methyl methacrylate together with 0.1 part of hydroquinone and 1.0 part of dibutyltin dilaurate, to which 286 parts of hydroxyethyl methacrylate are gradually added over 45 minutes. The prepolymer was prepared by adding the mixture and allowing the mixture to stand for an additional 90 minutes (during which time the temperature rose to about 50°C). The dispersion was then mixed with finely divided silica as described in Example 40.
1340 parts, 220 parts of the above prepolymer, 220 parts of methyl methacrylate, 60 parts of the dispersant solution described below, and water
Prepared by the method described in Example 40 from 1.2 parts.
This dispersion is extremely fluid with a viscosity of only 2.0 poise and is easily molded to contain 53.3% silica by volume and have a flexural modulus of
A composite material with excellent mechanical properties of 12.04 GN/m ² , bending strength 129.6 MN/m ² and impact strength 6.75 KJ/m ² was obtained. The dispersant solution used in this method was “Desmodur”
480 parts of N are dissolved in 806 parts of methyl methacrylate together with 0.1 part of hydroquinone and 1.0 part of dibutyltin dilaurate, then 260 parts of hydroxyethyl methacrylate are added over a period of 45 minutes, the mixture is allowed to stand for a further 1 1/2 hours, and finally γ - by adding 72 parts of aminopropyltrimethoxysilane and leaving the resulting mixture overnight. Comparative Example U The method of Example 46 was repeated without the dispersant solution and increasing the amount of prepolymer and methyl methacrylate to 250 parts each. The resulting dispersion was extremely viscous and could not be molded. Example 47 This example illustrates the use of a polystyrene-based polymer matrix with a filler obtained by milling in the presence of a dispersant and an interfacial binder. 1264 parts of coarse β-cristobalite silica, 497 parts of styrene, 3.5 parts of γ-methacryloxypropyltrimethoxysilane, 1.0 part of water, and 50 parts of a 25% solution of the copolymer dispersant described below in styrene as described in Example 5. It was ground in a ball mill by the method of The resulting dispersion contained 50.0% by volume of silica, with only
It had a viscosity of 0.6 poise. The dispersant used here is a block copolymer of cis-1:4-polyisoprene and poly(dimethylaminoethyl methacrylate) in a weight ratio of 1:1 (both polymer blocks have a molecular weight of 10,000). Comparative Example V The process of Example 47 was repeated without the dispersant solution and silane derivative and increasing the amount of styrene to 540 parts. The resulting dispersion contained 50.0% silica by volume.
It was viscous and extremely thixotropic. Example 48 This example and Examples 49 and 50 describe the use of barium sulfate as the inorganic filler in a polymerization system based on methyl methacrylate. Blanc Fixe (surface area 3.3m ² /g, average particle size 0.5~
1700 parts of 0.6 micron precipitated barium sulfate were dispersed in 500 parts of methyl methacrylate and 20 parts of the copolymer dispersant described in Example 5 using the method described in Example 40. A very fluid dispersion (viscosity 2.5 poise) containing 43.6% by volume of Blanc Fixe was thus obtained. Example 49 The method of Example 48 was repeated using 18 parts of the dispersant described in Example 18 as the copolymer dispersant and
The amount of Fixe was increased to 2330 parts and repeated. The resulting dispersion contained 50% filler by volume and had a viscosity of (a) 33 poise (spindle No. 4) and (b) 140 poise (spindle No. 7). The composite material obtained by curing this dispersion has a flexural modulus of 12.04GN/
m ² , bending strength 44.1MN/m ² , impact strength 1.68KJ/m ²
It had Example 50 The method of Example 49 was repeated by adding 5 parts of methacrylic acid after all of the Blanc Fixe was added. A rapid and substantial increase in the fluidity of the dispersion was observed upon this addition. This dispersion had a viscosity of only 1.0 poise, and the composite formed by its curing had a flexural modulus of 8.98 GN/m ² , a flexural strength of MN/m ² and an impact strength of 1.93 KJ/m ² . The improved flow properties of this dispersion can be attributed to the conversion of the tertiary amine anchoring groups in the dispersant copolymer to the corresponding methacrylate groups. Comparative Example W The method of Example 48 was repeated without using the copolymer dispersant. After adding only 15% by volume of Blanc Fixe to methyl methacrylate, the dispersion became so dilatant that no further filler could be added. Example 51 In this example and Example 52, a polymer matrix was obtained from a styrene-divinylbenzene-monobutyl maleate copolymer. 1300 parts of the finely divided silica described in Example 40, 180 parts of styrene, 20 parts of divinylbenzene (as a 54% solution in ethylvinylbenzene), 340 parts of monobutyl maleate and the copolymer dispersant described in Example 18. 9 parts using the method described in Example 40. The properties of the dispersion thus obtained containing 50% by volume of silica and of the intact molded sheet obtained by its degassing and curing are shown in Table 1. Example 52 The method of Example 51 was repeated by adding 5 parts of γ-methacryloxypropyltrimethoxysilane and 1 part of water to the mixture just before the final dispersion step at 1000 rpm. The properties of the resulting dispersion containing 50% by volume of silica and the cured composite formed are shown in Table 1. Comparative Example X The method of Example 51 was repeated without using the copolymer dispersant. When only about 42% by volume of silica was incorporated, the dispersion became extremely viscous and could not be molded.

[Table] Example 53 Calcium carbonate chalk No. 16 with the following particle size distribution: 17% by weight of particles larger than 20 microns 30% particles larger than 10 microns 53% particles larger than 5 microns 72% particles larger than 2 microns 970 parts An example
It was dispersed in 300 parts of methyl methacrylate containing 17 parts of the copolymer dispersant described in Example 40 using the method described in Example 40. The resulting dispersions were fluid with viscosities of (a) 124 poise (spindle No. 8) and (b) 31.5 poise (spindle No. 3). This was degassed and molded to obtain a composite sheet with a filler content of 55.4% by volume. Example 54 The method of Example 53 was repeated with the addition of 5 parts of methacrylic acid after complete addition of calcium carbonate. This increased the fluidity of the dispersion, whose viscosities were (a) 69 poise (spindle No. 8) and (b) 13 poise (spindle No. 3), and it could be more easily degassed and shaped. . Comparative Example Y The method of Example 53 was repeated without using the copolymer dispersant. Due to the high viscosity of the resulting dispersion, only about 40% by volume of calcium carbonate could be incorporated. Example 55 1600 parts of the fine silica described in Example 40 were mixed with 500 parts of butyl acrylate, 0.5 parts of polypropylene glycol dimethacrylate, 3.5 parts of γ-methacryloxypropyltrimethoxysilane, 0.7 parts of water, and butyl acrylate and dimethyl as dispersants. 90/10 copolymer with aminoethyl methacrylate 13
40 by the method described in Example 40.
A dispersion with a viscosity of 0.7 poise containing 57.7% silica by volume was thus obtained, which was easily degassed and molded into a composite sheet. Example 56 This example describes the production of a composite in which the polymer matrix was formed by ring-opening addition polymerization of an epoxy group-containing prepolymer. 40 parts of “Epikote” 828 (registered trademark of Shell Chemical; diepoxide produced by the reaction of diphenylpropane and epichlorohydrin)
Epoxide No. 8 (manufactured by Proctor and Gamble)
The mixture was mixed with 60 parts of a mixture of glycidyl ethers of C _12-14 monohydric alcohols and 5 parts of the dispersant described below. 245 parts of β-Cristobal silica sand was dispersed into this mixture using a transcavitation disperser. A fluid dispersion (viscosity 24 poise) containing 50% by volume of silica was thus obtained. 100 parts of this dispersion was polymerized by adding 3 parts of diethylenetetramine to obtain a hard and tough composite material. The dispersant used in this example was prepared by reacting 100 parts of "Epikote" 828 with 10 parts of p-nitrobenzoic acid and 1 part of dimethylaminoethanol at 140-150 DEG C. for 30 minutes. Similar dispersions obtained without the use of dispersants in the above method were much more viscous and therefore more difficult to form into satisfactory composites. Comparative example Z JP-A No. 48-68683 (Special Publication No. 54-3503)
To prepare a uniform raw material dispersion, 2 to 30% by weight of inorganic filler particles, such as titanium oxide or silica, are mechanically dispersed in a vinyl monomer in the presence of a polymer soluble in the vinyl monomer. , a method is described for producing thermoplastic resin compositions containing inorganic fillers by carrying out bulk polymerization therefrom. Examples of the vinyl monomer include styrene, or styrene and monomers copolymerizable with styrene, such as α-methylstyrene, acrylonitrile, methacrylic esters, or acrylic esters, and examples of polymers soluble in the vinyl monomer include: polystyrene,
Examples include styrene-α-methylstyrene copolymer, styrene-methyl methacrylate copolymer, and polybutadiene. In this conventional technique, a raw material dispersion is subjected to a mechanical dispersion operation to apply mechanical energy that can sufficiently disperse the inorganic filler, and once the filler particles are uniformly dispersed in the vinyl monomer medium, By using and dissolving a polymer soluble in vinyl monomer,
It has a thickening effect to maintain good dispersion of filler particles. However, it is stated that if too much polymer is used, the viscosity of the raw material dispersion becomes extremely high, which has the drawback that it cannot be charged with a conventional pump. The polymer in the prior art disclosed in the above-mentioned Japanese Patent Application Publication No. 2003-110023 is such that its entire molecule is soluble in the vinyl monomer medium, and acts as a thickener to increase the viscosity of the vinyl monomer medium by dissolving in the vinyl monomer medium. The increased viscosity prevents the dispersed particles from settling and maintains their dispersion. In this respect, the effect is different from that of the polymeric dispersant used in the present invention. The polymeric dispersant of the present invention has the advantage of making a mixture containing a volumetrically large amount of inorganic filler fluid and converting it into a dispersion liquid, and not unduly increasing the viscosity of the dispersion liquid. This method has the advantage of being able to uniformly disperse filler particles blended in a clearly large volumetric proportion, which has not been possible with technology, and of maintaining good dispersion. The following experiment was conducted to illustrate this point. That is, in order to prepare a composition by mixing each component shown in Table 1 below, each component was mixed in a 2.5 capacity ball mill equipped with steatite balls having a diameter of 9 mm. In each experiment, styrene was used as the polymerizable organic liquid (vinyl monomer), and titanium oxide (TiO ₂ , trade name Tioxide R-TC-30, manufactured by British Titanium Products Ltd., UK) was used as the inorganic filler. was used. The "dispersant" used was polystyrene (Styron 686/7 manufactured by Dow Chemical Company, USA) in the comparative experiment according to the method of JP-A-48-68683, and in the case of the experiment according to the present invention, it was polystyrene (Styron 686/7 manufactured by Dow Chemical Company, USA). The polymeric dispersant used in Example 18 (i.e., a (95:5) copolymer of methyl methacrylate and dimethylaminoethyl methacrylate). In each experiment, the "dispersant" was dissolved in styrene and then ball milled. When fillers were added, the material was ball milled for 2 hours and the viscosity of the resulting dispersion was measured. The results are shown in the table below.

[Table] From the table above, the amount of filler blended is 60% by weight.
(equivalent to approximately 25% by volume), JP-A-48-
According to the method of No. 68683, only a hard paste-like mixture is obtained which has no fluidity and cannot be easily handled, whereas according to the present invention, a dispersion liquid composition is obtained, and this viscosity is very high. It had low fluidity and exhibited a viscosity value not much different from that when 15% by weight of filler was blended using the method of JP-A-48-68683. (b) Used in the above experiment (a) as a polymeric dispersant according to the present invention in the production of a mixture of silica powder (average particle size 10 microns or less) in the monomer methyl methacrylate. 1% by weight of methyl methacrylate/dimethylaminoethyl methacrylate (95:5) copolymer was added. A 1% by weight styrene/acrylonitrile (75:25) copolymer was used as a comparative "dispersant." The latter is a simple random copolymer that is soluble in methyl methacrylate monomer (MMA) but does not contain groups (or moieties) that anchor to the silica particle surface. These "dispersants" were first dissolved in methyl methacrylate, then silica powder was added and mixed in a flask with a stirrer. The viscosity of the resulting mixture was measured. The results are shown in the table below.

[Table] As is clear from the above table, in a simple styrene/acrylonitrile random copolymer,
When incorporating fillers (silica) in high volumetric contents, there is a complete lack of ability to disperse the fillers homogeneously and maintain good dispersion.

Claims (1)

[Claims] 1. A polymerizable organic liquid (A) that can produce a hardened solid organic polymer when polymerized and cured and has a viscosity of 50 poise or less at the initial temperature during polymerization and molding; High fluidity consisting of at least one inorganic filler fine particle (B) with a shear modulus of 5 GN/m ² or more dispersed in an organic liquid and an amphiphilic polymeric dispersant (C) In the molding composition, the inorganic filler fine particles (B) account for 35 to 90% (by volume) of the total volume of the molding composition, and are present in the composition. The maximum particle size of all or substantially all of the inorganic filler fine particles does not exceed 100 microns, at least 95% of the particles, calculated by number of particles, have a particle size of 10 microns or less, and the surface area of the particles is 30m ² /cc
In addition, the ^amphiphilic polymeric dispersant (C) has a molecular weight of 500 or more that is solvated by and soluble in the polymerizable organic liquid (A). At least one chain component (i) of The polymeric dispersant (C) contains at least a polymeric dispersant (C) based on the total particle surface area of the dispersed inorganic filler fine particles (B).
It is blended in an amount of 0.01 g/m ² and is a dispersion liquid with good dispersion stability in which the inorganic filler fine particles (B) are stably maintained in a non-agglomerated state in the polymerizable organic liquid (A). A molded article made by polymerizing and curing a fluid molding composition containing a high content of inorganic filler fine particles in a mold without mechanical stirring. , and in the molded article, the inorganic filler particles (B) are uniformly dispersed in the solid polymer phase produced by polymerization and curing of the polymerizable organic liquid (A), and the inorganic filler particles (B) have a volume of 35% of the volume of the molded article. A molded article of cured organic polymer filled with a high content of inorganic filler particulates, characterized in that the content is in an amount of ~90% (by volume).