JPH0143768B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermosetting unsaturated polyester resin composition having excellent impact resistance, surface properties, weather resistance, and heat aging resistance. The unsaturated polyester resin is produced by combining an unsaturated polyester obtained by a dehydration condensation reaction between an α,β-unsaturated dibasic acid or a mixture of this and a saturated dibasic acid with a polyhydric alcohol, and the unsaturated polyester such as styrene. It is dissolved in a copolymerizable vinyl monomer, and further blended with a curing agent, glass fiber, inorganic filler, pigment, etc., and polymerized and cured. Such unsaturated polyester resins generally exhibit a volume shrinkage of 4 to 12% during curing, which causes phenomena such as warpage and corrugation in molded products. To improve this, polystyrene or polymethyl methacrylate, etc. of thermoplastic resin is added. The unsaturated polyester resin thus obtained is used as a thermosetting resin with excellent mechanical strength, chemical resistance, heat resistance, electrical properties, etc. for automobile parts, electrical equipment parts, industrial parts, other furniture, bathtubs, etc. It is used in a wide range of fields such as toilet tanks. In recent years, as the movement to reduce the weight of automobiles has become more active, attempts have been made to use unsaturated polyester resins for automobile exterior panel parts and structural parts. In these applications, it is usually used in the form of bulk molding compound (BCM) or sheet molding compound (SMC), which can be easily molded.
In particular, there is a tendency for the impact resistance or surface performance of cured products to be more important than ever, and improvement thereof has become an important issue. Many attempts have been made to improve the impact resistance or surface properties of unsaturated polyester resins, and a typical example is the addition of diene rubber. For example, JP-A-48-34289 and JP-A-49-30480 disclose a method of adding a styrene-butadiene block copolymer. However, with these methods, the rubber component and unsaturated polyester component separate when each component is blended or when the compound is left for a long time, resulting in a cured product with poor impact resistance and surface properties. This is the actual situation. In an attempt to improve this drawback, Japanese Patent Application Laid-open Nos. 148588-1988 and 1983-
No. 130653 proposes a method of adding a styrene-butadiene block copolymer containing a carboxyl group or a salt thereof at the molecular end. However, even with this method, the problem of layer separation between the rubber component and the unsaturated polyester component cannot be essentially solved, and impact resistance and surface properties have not been successfully improved. In view of the current situation, the present inventors have conducted extensive studies on improving the impact resistance and surface properties of unsaturated polyester resin compositions containing styrene-butadiene block copolymers as additives, and have developed a styrene-butadiene block copolymer. Dicarboxylic acid group/
It was discovered that the object could be achieved by using a modified block copolymer to which a derivative group thereof is bonded.
Proposed in No. 16568. Subsequently, the present inventors conducted further studies on improving the properties of unsaturated polyester resin compositions using such modified block copolymers. We have discovered that by using a modified block copolymer in which molecular units containing The present invention has now been completed. That is, the present invention comprises (a) an unsaturated polyester resin (b) at least one vinyl aromatic compound polymer block A and at least one olefin compound polymer block B having a degree of unsaturation not exceeding 20%.
unique, and has a low content of vinyl aromatic compounds.
A modified block copolymer (c) in which one or more molecular units containing a carboxylic acid group or its derivative group are bonded to a block copolymer of 10 to 90% by weight per polymer molecule of the block copolymer. A composition comprising a vinyl monomer (d) and a curing agent, characterized in that the modified block copolymer (b) component contains 0.05 to 5% by weight of unreacted unsaturated carboxylic acid or a derivative thereof. The present invention relates to a thermosetting unsaturated polyester resin composition. In the thermosetting unsaturated polyester resin composition of the present invention, the modified block copolymer used as the modifier has extremely excellent affinity for inorganic fillers such as calcium carbonate and glass fibers. Separation of the unsaturated polyester component and the modified block copolymer component is extremely difficult to occur in the presence of an inorganic filler or glass fiber. Therefore, the resin composition of the present invention can be molded with a uniform material composition even when the components are mixed and left for a long time, and a molded product having uniform mechanical strength and impact resistance can be obtained. Further, problems such as roughness on the surface of the molded product that occurs when the unsaturated polyester resin component and rubber component are separated, and mold contamination during the curing process do not occur. In addition, the modified block copolymer used in the present invention has the effect of suppressing the shrinkage that occurs when unsaturated polyester resin is cured, and is free from defects such as warping, corrugation, and embossment of inorganic fillers and glass fibers. Molded products with excellent surface smoothness and gloss can be obtained. Furthermore, in the modified block copolymer used in the present invention, the degree of unsaturation of the olefin compound polymer block is 20.
%, so molding has superior weather resistance and heat aging resistance compared to conventional block copolymers with a high degree of unsaturation, such as styrene-butadiene block copolymers. Goods can be obtained. In the thermosetting unsaturated polyester resin composition of the present invention, some or all of the carboxylic acid groups or derivative groups thereof of the modified block copolymer are ionically crosslinked by a thickener such as magnesium oxide, so that they The thickening effect of BMC is remarkable.
Suitable for applications such as and SMC. In addition, the resin composition of the present invention has excellent affinity for inorganic fillers because the modified block copolymer has an excellent ability to prevent sedimentation of inorganic fillers. It can also be used in the field of molding using relatively low viscosity molding materials, such as molding, preform matte tie molding, matte matte die molding, cold press molding, injection molding, and cast molding. The present invention will be explained in detail below. The unsaturated polyester resin, which is component (a) of the composition of the present invention, is obtained by a condensation reaction of an α,β-unsaturated dibasic acid or a mixture thereof with a saturated dibasic acid and a polyhydric alcohol. It is something. Examples of the dibasic acid component include maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, chlorinated maleic acid, glutaconic acid, and acid anhydrides thereof. Saturated dibasic acids include phthalic acid, halogenated phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hettic acid, endomethylenetetrahydrophthalic acid, succinic acid,
Mention may be made of adipic acid, glutaric acid, sebacic acid, pimelic acid or acid anhydrides thereof. Furthermore, if necessary, monobasic acids such as acrylic acid and methacrylic acid, and polybasic acids such as trimellitic acid, hemimelittic acid, and trimesic acid may be used in combination with the above-mentioned dibasic acids as modifiers. Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butanediol, tetramethylene glycol, 1,6-
hexanediol, neopentyl glycol,
Examples include 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and adducts of bisphenol A with ethylene oxide and/or propylene oxide. Further, if necessary, higher aliphatic alcohols such as amyl alcohol, hexyl alcohol, pentyl alcohol, octyl alcohol, etc., monohydric alcohols such as tetrahydrofurfuryl alcohol, glycerin, pentaerythritol, trimethylolethane, sorbitol, etc. A polyhydric alcohol can also be used in combination with the above polyhydric alcohol as a denaturing agent. The modified block copolymer which is component (b) of the composition of the present invention has at least one vinyl aromatic compound polymer block A and at least one unsaturation.
A block copolymer consisting of not more than 20% olefin compound polymer block B (hereinafter referred to as
It is a modified block copolymer in which a molecular unit containing a carboxylic acid group or its derivative group is bonded to a "basic block copolymer"). Here, the olefin compound polymer block refers to monoolefins such as ethylene, propylene, 1-butene, isobutylene, conjugated diolefins such as butadiene, itaprene, 1,3-pentadiene, 1,4-hexadiene, norbornene, norbornene derivatives, etc. one or more olefin compounds selected from non-conjugated diolefins are polymerized,
Alternatively, it is a polymer block having a copolymerized form, and the degree of unsaturation of the block is 20% or less. Therefore, when the above diolefins are used as monomers constituting an olefin compound polymer block, the degree of unsaturation in the block portion is 20%.
Measures must be taken to reduce the degree of unsaturation by methods such as hydrogenation to an extent that does not exceed .
Further, a vinyl aromatic compound may be randomly copolymerized in the olefin compound polymer block. In the present invention, the "basic block copolymer" includes a hydrogenated block copolymer consisting of a vinyl aromatic compound and a conjugated diene compound, a block copolymer of a vinyl aromatic compound and a monoolefin, etc. Can be mentioned. The modified block copolymer used in the present invention can be produced by subjecting the above-mentioned "substrate block copolymer" to an addition reaction with an unsaturated carboxylic acid or a derivative thereof. In the present invention, the most preferred modified block copolymer as component (b) is a block copolymer (hereinafter referred to as The degree of unsaturation of the conjugated diene moiety of the "block copolymer as a precursor" is 20%.
This is a modified block copolymer obtained by selectively hydrogenating to an extent not exceeding 100%, and then bonding an unsaturated carboxylic acid or a derivative thereof by an addition reaction. "Block copolymer as a precursor" is one containing at least one, preferably two or more vinyl aromatic compound polymer blocks and at least one conjugated diene-based polymer block. . Here, the polymer block mainly composed of a conjugated diene is a polymer having a composition range of a vinyl aromatic compound and a conjugated diene compound in a weight ratio of 0/100 to 50/50, preferably 0/100 to 30/70. The distribution of vinyl aromatic compounds in this block is random, tapered (increasing or decreasing monomer content along the molecular chain),
It may be partially block-shaped or any combination thereof. Incidentally, in the "block copolymer as a precursor" in the present invention, the content of the vinyl aromatic compound is contained in the transition region between the vinyl aromatic compound polymer block and the polymer block mainly composed of a conjugated diene compound. Although there may be a copolymer block of a vinyl aromatic compound and a conjugated diene compound in which the amount exceeds 50% by weight, such a polymer block shall be included in the above-mentioned polymer block mainly composed of a conjugated diene compound. . In the "block copolymer as a precursor", the weight ratio of the vinyl aromatic compound content to the conjugated diene compound content is in the range of 10/90 to 90/10, and 15/85 to 85/15. A range of is preferred. Such a block copolymer exhibits properties as a thermoplastic elastomer when the content of the vinyl aromatic compound is about 60% by weight or less, preferably 55% by weight or less,
It is suitably used as a "block copolymer as a precursor." The vinyl aromatic compounds constituting the "block copolymer as a precursor" include styrene, α-
1 from methylstyrene, vinyltoluene, etc.
One or more types are selected, with styrene being particularly preferred. The conjugated diene compound is selected from one or more of butadiene, isoprene, 1,3-pentadiene, etc., and butadiene and/or isoprene are particularly preferred. The above block copolymer has a number average molecular weight of
The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) is preferably in the range of 1.05 to 10. The molecular structure of the block copolymer may be linear, branched, radial, or a combination thereof. Further, when butadiene is used as the conjugated diene compound in the block copolymer, the amount of 1,2 bonds in the microstructure of the butadiene portion is preferably in the range of 10 to 80%.
When it is necessary to impart rubber elasticity to the modified block copolymer, the amount of 1,2 bonds is preferably in the range of 25 to 65%, particularly preferably in the range of 35 to 55%. When the above-mentioned block copolymer contains two or more vinyl aromatic compound polymer blocks or polymer blocks mainly composed of a conjugated diene compound, each block may have the same structure, or the monomer components Each structure such as content, distribution in their molecular chains, molecular weight of the block, microstructure, etc. may be different. Examples of methods for producing "block copolymers as precursors" include Japanese Patent Publication No. 36-19286, Japanese Patent Publication No. 43-14979, Japanese Patent Publication No. 49-36957,
Examples include methods described in Japanese Patent Publication No. 48-2423 and Japanese Patent Publication No. 48-4106. All of these methods use an organic lithium compound or the like as an anionic polymerization initiator in a hydrocarbon solvent, and if necessary, an ether compound such as diethyl ether or tetrahydrofuran, triethylamine, or
Tertiary amines such as N,N,N',N'-tetramethylethylenediamine, Lewis bases such as phosphine compounds such as hexamethylphosphoamide, and polyfunctional compounds such as silicon tetrachloride and epoxidized soybean oil as coupling agents. This is a method of block copolymerizing a vinyl aromatic compound and a conjugated diene compound using the following method, and a block copolymer having a linear, branched or radial structure is obtained.
In the present invention, any polymer obtained by any polymerization method can be used as long as it falls within the above range. Furthermore, it is also possible to use not only one type of block copolymer but also a mixture of two or more types. “Block copolymer as a precursor” above
is hydrogenated by a known method, for example, the method described in Japanese Patent Publication No. 42-8704, to obtain a "base block copolymer". The ``substrate block copolymer'' means that at least 80% of the aliphatic double bonds based on the conjugated diene compound in the ``precursor block copolymer'' polymer block mainly consists of a conjugated diene compound. In other words, the degree of unsaturation in the block morphologically converted to olefin compound polymer block B by hydrogenation of the polymer block mainly composed of a conjugated diene compound is 20%. It is necessary not to exceed it. If the degree of unsaturation of the olefin compound polymer block exceeds 20%, it is not preferable because the weather resistance and heat aging resistance of molded articles of the unsaturated polyester resin composition will be poor. On the other hand, hydrogen of the aromatic double bond based on the vinyl aromatic compound copolymerized in the vinyl aromatic compound in the vinyl aromatic compound polymer block and, if necessary, in the polymer block mainly composed of a conjugated diene compound. Although there is no particular restriction on the addition rate, it is preferable that the hydrogenation rate is 20% or less. The degree of unsaturation of the olefin compound polymer block can be measured by instrumental analysis using an infrared spectrophotometer (IR), nuclear magnetic resonance (NMR), etc., titration analysis using iodometry, etc. The "base block copolymer" is then
The modified block copolymer used in the present invention is synthesized by modification by an addition reaction with an unsaturated carboxylic acid or a derivative thereof. Examples of unsaturated carboxylic acids or derivatives thereof are maleic acid, fumaric acid, itaconic acid, halogenated maleic acid, cis-
4-cyclohexene-1,2-dicarboxylic acid, endo-cis-bicyclo[2,2,1]-5-heptene-2,3-dicarboxylic acid, etc., and acid anhydrides, esters, amides, imides of these dicarboxylic acids Examples include acrylic acid, methacrylic acid, and esters and amides of these monocarboxylic acids. These can be used not only alone but also as a mixture of two or more. Among these, unsaturated dicarboxylic acids or derivatives thereof are preferred, and maleic anhydride is particularly preferred. A modified block copolymer is produced by adding an unsaturated carboxylic acid or a derivative thereof to a "substrate block copolymer" in a solution or melt state, with or without the use of a radical initiator. can get. The method of producing these modified block copolymers is not particularly limited in the present invention, but the modified block copolymers obtained may contain undesirable components such as gels, or have a significantly increased melt viscosity and may be difficult to process. A manufacturing method that deteriorates properties is not preferred. A preferred method includes, for example, a method in which a "substrate block copolymer" is reacted with an unsaturated carboxylic acid or a derivative thereof in the presence of a radical initiator in an extruder. The amount of molecular units containing a carboxylic acid group or its derivative group contained in the modified block copolymer, that is, the amount of unsaturated carboxylic acid or its derivative added, is the average value of the entire modified block copolymer used in the present invention. The number is 1 or more, preferably 3 to 200, more preferably 5 to 50 per molecule of the "substrate block copolymer".
If the amount added is other than this, the properties of the resin composition of the present invention or its cured resin composition will be lost. In particular, the above conditions are necessary to obtain thickening properties and uniformity of the resin composition, and uniform mechanical strength, impact resistance, and surface properties of the cured resin composition. The content of molecular units containing carboxylic acid groups or derivative groups thereof in the modified block copolymer can be easily determined by methods such as infrared spectrophotometry and titration. Furthermore, in the present invention,
Even if an unmodified block copolymer is included, as long as the amount of unsaturated carboxylic acid or its derivative added in the modified block copolymer used as component (b) satisfies the above range as an overall average value. good. In the method for producing a modified block copolymer as described above, unreacted unsaturated carboxylic acids or derivatives thereof generally remain in the modified block copolymer, but in the present invention, this unreacted material is identified. It is necessary to leave the same amount. That is, in the present invention, these unreacted substances are left in the modified block copolymer at a ratio of 0.05 to 5% by weight, preferably 0.1 to 3% by weight. The remaining unreacted material has an advantageous effect in improving the workability of dissolving the modified block copolymer in the vinyl monomer. The vinyl monomer used as component (c) in the present invention acts as a crosslinking component. Examples of vinyl monomers include styrene, various substituted products of styrene, such as α-methylstyrene, vinyltoluene, dimethylstyrene, trimethylstyrene, halogenated styrene, tert-butylstyrene, styrene sulfonate, aminostyrene, Vinyl aromatic compounds such as P-benzystyrene and P-phenoxystyrene, acrylic acid or methacrylic acid and methyl alcohol, ethyl alcohol, propyl alcohol, octyl alcohol, hexanol, tetrahydrofurfuryl alcohol, ethylene glycol, propylene glycol, etc. esters with aliphatic alcohols such as acrylic acid or methacrylic acid derivatives such as 2-aminoethyl-methacrylate, N,N-diethylamino-acrylate, N,N-diethylamino-methacrylate, maleic acid, fumaric acid, crotonic acid, itaconic acid α,β-unsaturated dicarboxylic acids such as or their anhydrides, esters, amides, imides, etc., fumaric acid esters such as diethyl- and dioctyl fumarate, as well as various vinyl and vinylidene monomers, such as acrylonitrile, Methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, vinylene carbonate, vinyl-2
-chloroethyl ether, _C8 - _C18 alkyl vinyl ether, vinyl ester of _C8 - _C18 fatty acid, 2-vinylfuran, vinylphenol, vinylphenyldisiloxane, 2-vinylpyridine,
4-vinylpyridine, vinylpyrrole, vinylpyrrolidone, vinylsulfonic acid, vinylurethane,
Examples include methylvinylketone-2-vinylquinoline and vinylcarbazole. Also, 1,3
- Conjugated diene compounds such as butadiene, isoprene, piperylene, methylpentadiene, chloroprene, and 2-methoxybutadiene and 1
Alkoxy- and cyano derivatives of conjugated dienes such as -cyanobutadiene can also be used. moreover,
Polyfunctional crosslinkable vinyl monomers such as diallyl maleate, diallyl phthalate, divinylbenzene, divinyl ether, neopentyl glycol diacrylate, diallyl cyanurate, triallyl cyanurate, diallylphenyl phosphate, 2,3-divinylpyridine , divinylsulfone, 2,5-divinyl-6-methylpyridine, etc. can also be used. Preferred examples of these vinyl monomers include:
Examples include styrene, vinyltoluene, α-methylstyrene, chlorostyrene, divinylbenzene, methyl methacrylate, methyl acrylate, diallyl phthalate, and triallyl cyanurate. The curing agent as component (d) used in the present invention is:
Organic peroxides, organic hydroperoxides and azo compounds can be used. Some peroxides useful in this invention include dialkyl peroxides and diacyl peroxides. Alkyl peroxide has the general structure R-OO-
R', where R and R' are the same or different primary, secondary or tertiary alkyl, cycloalkyl, aralkyl or heterocyclic groups. Groups of peroxides suitable for use in the present invention include dicumyl peroxide, di-tert-
Included are butyl peroxide, tert-butylcumyl peroxide and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane. Diacyl peroxide has the general structure RC(O)
OOC(O)R', in which R and R' are the same or different alkyl groups, cycloalkyl groups,
It is an aralkyl group, an aryl group or a heterocyclic group. Examples of some diacyl peroxides suitable for use in the present invention include dilauroyl peroxide, dibenzoyl peroxide, dicetyl peroxide, didecanoyl peroxide, di-(2,4-dichlorobenzoyl) peroxide, There are diisononanoyl peroxide and 2-methylpentanoyl peroxide. Additionally, other peroxides useful in the present invention include methyl ethyl ketone peroxide, cyclohexanone peroxide, and the like, along with particularly preferred peresters such as tert-butyl peroctoate and tert-butyl perbenzoate. Examples of hydroperoxides suitable for use in the present invention include tert-butyl hydroperoxide, cumyl hydroperoxide, 2,5
-dimethyl-2,5-dihydroperoxyhexane, P-methane hydroperoxide and diisopropylbenzene hydroperoxide. Examples of azo compounds that can be used in the present invention include diazoaminobenzene, N,N'-dichloroazodicarboxylic acid amide, azodicarboxylic acid diethyl ester, 1-cyano-1-(tert-butylazo)cyclohexanone, and azobis(iso butyronitrile). The composition ratio of each component constituting the composition of the present invention is within the following range based on 100 parts by weight of each component (a), (b), and (c). That is, component (a) is 10~
The amount is in the range of 90 parts by weight, preferably 20 to 80 parts by weight, and more preferably 20 to 60 parts by weight. (b) Ingredients are 2~
The amount is 70 parts by weight, preferably 5 to 50 parts by weight, and more preferably 5 to 40 parts by weight. (c) Ingredients are 10~
80 parts by weight, preferably in the range 20-70 parts by weight. Further, the amount of the curing agent used in the present invention is 0.1 to 10 parts by weight, preferably 0.3 parts by weight, based on the total of 100 parts by weight of components (a), (b), and (c) of the composition of the present invention. ~5
Parts by weight, more preferably 0.5 to 3 parts by weight. Other additives such as thickeners, fiber reinforcing agents, inorganic fillers, low shrinkage agents, pigments, colorants, lubricants, mold release agents, etc. may be added to the composition of the present invention as necessary. Can be done. Thickeners used in the present invention include oxides and/or hydroxides of metals from Group Group of the Periodic Table, such as magnesium, calcium,
Selected from strontium, barium and zinc oxides and hydroxides. Preferred are magnesium and/or calcium oxides or hydroxides. The above-mentioned thickener is used in an amount of 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, based on a total of 100 parts by weight of components (a), (b), and (c) of the composition of the present invention. used. The fiber reinforcing agent used in the present invention includes glass, metal,
Silicate, asbestos, cellulose, carbon, graphite, polyester, polyacrylic, polyamide,
Selected from fibers such as polyolefin. Preferred is glass fiber. The above fiber reinforcing agent comprises component (a) of the composition of the present invention,
5 to 300 parts per 100 parts by weight of component (b) and component (c)
The amount used is preferably 20 to 200 parts by weight, more preferably 20 to 100 parts by weight. The filler used in the present invention is preferably an inorganic particulate filler, such as calcium carbonate, calcium silicate, silica, calcined clay, chalk, talc, limestone, anhydrous calcium sulfate, barium sulfate, asbestos,
Selected from powdered glass, quartz, aluminum hydrate, aluminum oxide, antimony oxide, etc. The above filler is component (a) of the composition of the present invention, and (b)
It is used in an amount of 50 to 800 parts by weight, preferably 100 to 400 parts by weight, and more preferably 100 to 300 parts by weight, based on a total of 100 parts by weight of component (c). Low shrinkage agents that can be used in the present invention include homogeneous polymers such as polystyrene, poly(meth)acrylate, polyvinyl acetate, polyvinyl chloride, polyethylene, polypropylene, polyamide, polycarbonate, and cellulose polymers. selected from polymers or copolymers. Main copolymers include homopolymers of methyl methacrylate, ethyl methacrylate, butyl methacrylate and ethyl acrylate, and copolymers of methyl methacrylate with acrylic acid and methacrylic acid and/or their lower alkyl esters. Examples include copolymers of methyl methacrylate containing a small amount of one or more of lauroyl methacrylate, isobornyl methacrylate, acrylamide, hydroxyethyl methacrylate, styrene, 2-ethylhexyl acrylate, acrylonitrile, methacrylic acid, methacrylamide, methyloylacrylamide, and cetylstearyl methacrylate. be able to. Other useful copolymers include styrene-acrylonitrile, vinyl chloride-vinyl acetate, and the like. These low shrinkage agents are used in an amount of 0 to 40 parts by weight, preferably 0 to 20 parts by weight, based on a total of 100 parts by weight of components (a), (b), and (c) of the composition of the present invention. used in amounts of In addition to the above, the composition of the present invention may also contain, for example, pigments, colorants, lubricants or mold release agents, stabilizers, silane coupling agents, flame retardants, and the like.
Specific examples of pigments include titanium oxide, carbon black, and phthalocyanine. Examples of lubricants or mold release agents include aluminum, calcium, magnesium, and zinc salts of stearic acid. Stabilizers include barium, tin octoate, tris (nonylphenyl) phosphite, alkyl phenols such as BHT, quinones,
There are amines, etc. A preferred method for producing the thermosetting unsaturated polyester resin composition of the present invention is as follows. That is, a first mixture containing an unsaturated polyester resin as the component (a) of the present invention and a vinyl monomer as the component (c), a modified block copolymer as the component (b), and a component (c). A solution of a second mixture with a certain vinyl monomer is mixed with a solution of a second mixture, and at this time, either or both of the first mixture and the second mixture is added with a curing agent and, if necessary, a filler, a fiber reinforcing agent, and an additive. sticky agent,
This manufacturing method involves mixing additives such as a low shrinkage agent and a mold release agent. Preferably, the filler is mixed into the second mixture. The above method is a preferred method for suppressing layer separation between the modified block copolymer and the unsaturated polyester resin. The thermosetting unsaturated polyester resin composition of the present invention described above is preferably molded by a method such as compression molding or injection molding after passing through an intermediate form such as BMC or SMC, and is molded into automobile parts, transportation equipment such as boats, bathtubs, etc. , construction equipment such as septic tanks, and other industrial products. Examples 1-2, Comparative Examples 1-6 and Reference Examples 1-
4 (1) Preparation of unsaturated polyester resin A mixture consisting of 0.7 mol of maleic anhydride, 1.4 mol of phthalic anhydride, 2.0 mol of propylene glycol, and 0.2 mol of diethylene glycol was heated to about 100°C under a nitrogen stream, and stirred. The temperature was gradually raised to about 210°C while condensed water was removed from the system, and an esterification reaction was carried out at this temperature to synthesize an unsaturated polyester resin with an oxidation level of 40. This unsaturated polyester resin was dissolved in styrene to obtain a solution with a solid content concentration of 65% by weight (hereinafter referred to as sample A-1). Next, 0.6 mole of isophthalic acid, phthalic anhydride
A mixture consisting of 0.6 mol of maleic anhydride, 1.4 mol of propylene glycol, and 2.6 mol of propylene glycol was subjected to an esterification reaction in the same manner as above, and 30 mol of oxidized
An unsaturated polyester resin was synthesized. This unsaturated polyester resin was dissolved in styrene to obtain a solution with a solid content concentration of 65% by weight (hereinafter referred to as sample A).
-2). (2) Preparation of hydrogenated block copolymer By anionic block copolymerization of butadiene and styrene using n-butyllithium as a polymerization catalyst and tetrahydrofuran as a vinyl content regulator in n-hexane or cyclohexane solvent. The block copolymers shown in Table 1 were synthesized.

[Table] Next, the block copolymers shown in Table 1 were
- Hydrogenation is performed in a mixed solvent of hexane and cyclohexane or in a cyclohexane solvent using cobalt naphthenate and triethylaluminum as catalysts at a hydrogen pressure of 7 kg/cm ² and a temperature of 50°C for 5 hours to remove the double bond in the butadiene block. Approximately 90
A selectively hydrogenated block copolymer was synthesized in which % of the styrene block was hydrogenated and the benzene ring in the styrene block remained almost unhydrogenated. The metal remaining on the catalyst was removed by washing with an aqueous hydrochloric acid solution and methanol. (3) Preparation of modified block copolymer Hydrogenated block copolymer 100 synthesized in (2) above
3 parts by weight of maleic anhydride,
After uniformly mixing 0.1 part by weight of Perhexa 25B (manufactured by NOF Corporation), a screw type extruder (single screw, screw diameter 20 mm, L/D
=24, full flight type screw),
The maleation reaction was carried out at a cylinder temperature of 250°C. From the obtained modified block copolymer, unreacted maleic anhydride was removed under reduced pressure and 2,6-di-tert-butyl-4 was added as a stabilizer.
- Methylphenol (BHT) was added in an amount of 0.5 parts by weight per 100 parts by weight of the polymer. When this hydrogenated block copolymer was analyzed, the results shown in Table 2 were obtained. In addition, in sample C-4, in order to investigate the effect of maleic anhydride remaining in the modified block copolymer, a sample was used that was not subjected to a treatment to remove unreacted maleic anhydride after the maleation reaction. .

[Table] (4) Preparation of maleic anhydride-modified styrene-butadiene block copolymer 3 parts by weight of maleic anhydride was uniformly added to 100 parts by weight of the styrene-butadiene block copolymer of sample B-1 in Table 1. After mixing, the mixture was fed to the same extruder as above under a nitrogen atmosphere, and a maleation reaction was carried out at a cylinder temperature of about 220°C. After that, unreacted maleic anhydride was removed under reduced pressure, and BHT was added as a stabilizer at 0.5 parts per 100 parts by weight of the polymer.
Part by weight was added. The maleic anhydride-modified styrene-butadiene block copolymer thus obtained (hereinafter referred to as sample D-1) has an average content of about 10 maleic anhydrides per molecule of the polymer. . (5) Preparation of block copolymer containing terminal carboxyl groups Using n-butyl lithium as a polymerization catalyst, a living polymer obtained by sequentially polymerizing styrene and butadiene in a cyclohexane solvent was reacted with carbon dioxide gas, and then treated with hydrochloric acid. A styrene-butadiene block copolymer with a styrene content of 40% by weight and a number average molecular weight of 65,000, containing one terminal carboxyl group in the polymer (hereinafter referred to as sample E).
−1) was obtained. The block copolymers of samples B to E obtained as described above were used in the following examples, but each of these was dissolved in styrene in advance and used as a styrene solution with a solid content concentration of 30% by weight. did. First, samples B-1, B-3, C-1, C-3, C
The thickening effect of the styrene solutions of -4 and E-1 was investigated, and the results are shown in Table 3. From Table 3, the modified block copolymer (sample C-4) within the scope of the present invention is different from the unmodified block copolymer (sample B-1, B-3) outside the scope of the present invention and the terminal carboxyl group-containing It can be seen that the thickening phenomenon after addition of magnesium oxide was extremely remarkable compared to the block copolymer (Sample E-1). In addition, if unreacted maleic anhydride remains in the modified block copolymer, the viscosity of the styrene solution before adding magnesium oxide will be low, making it difficult to dissolve the modified block copolymer or blend the styrene solution with other components. It is also clear that it is advantageous.

[Table] Next, a resin composition before curing was obtained according to the formulation () shown in Table 4. The resin composition was prepared as follows. After mixing the styrene solution of the block copolymer, zinc stearate, and half the amount of calcium carbonate to be blended, a styrene solution of an unsaturated polyester resin mixed with tert-butyl perbenzoate was added and mixed. Next, the remaining calcium carbonate, pigment, magnesium hydroxide, and glass fiber were sequentially added and mixed to this mixture to obtain a resin composition before curing. The above resin composition was heated at a temperature of 150℃ and a pressure of 100Kg/
A plate of 200 x 200 x 3 mm was compression molded at cm ² for 3 minutes, and the physical properties of the molded plate were measured. In addition, a resin composition for evaluating thickening properties was prepared in the same manner as the above-mentioned preparation method except that glass fiber was not added, and the resin composition was aged at room temperature to examine the thickening effect. The results are shown in Table 5. Table 5 shows that the unsaturated polyester resin composition containing the modified block copolymer within the range of the present invention has a rapid thickening effect and is excellent in tensile strength, dart impact strength, surface properties, etc.

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[Table] Reference Example 5 and Comparative Examples 7 to 9 Using the same molded plates as those used in the reference examples above, weather resistance tests and heat aging resistance tests were conducted as follows. In the weather resistance test, the dart impact strength of the molded plate was measured after being exposed to a weatherometer for 1000 hours. In the heat aging resistance test, the molded plate was left in an atmosphere at 200°C for 100 hours, and then the dart impact strength was measured. The results are shown in Table 6, and the cured product of the resin composition of the reference example shows almost no decrease in dart impact strength even after the weather resistance test and the heat aging test, indicating that it has extremely excellent durability. I understand.

[Table] A molded plate molded using the same method as in 2 was used.
Example 3, Comparative Examples 10 to 12 and Reference Example 6 After preparing a resin composition before curing according to the formulation () shown in Table 4 in the same manner as in the above example, this resin composition was processed using an SMC manufacturing machine. The chopped strands were continuously spread on a polyethylene sheet and cut into 1-inch pieces, and the chopped strands were evenly dropped and dispersed so that the glass fiber content was 25%, and then the top surface was further covered with a polyethylene sheet. A SMC with a width of 1 m and a thickness of 2 mm was manufactured by passing it through a pressure roll. After aging this SMC for 1 to 3 days, it was press-molded for 5 minutes at 140° C. and about 100 kg/cm ² to obtain a molded product. Workability during molding, dart impact strength, and appearance characteristics of the molded product were evaluated, and the results are shown in Table 7. It has been found that unsaturated polyester resin compositions containing modified block copolymers within the scope of the present invention are excellent in workability during molding, impact resistance, and appearance characteristics. Next, the weather resistance and heat aging resistance of these molded articles were evaluated using the same method as in the above-mentioned Reference Examples. As a result, the molded article of the resin composition of the present invention showed almost no decrease in impact strength, whereas the molded article of the comparative example showed a decrease of 20% or more in impact strength.

【table】

[Table] Reference Example 7 Styrene solution of unsaturated polyester (Sample A-
2) 75 parts by weight, 25 parts by weight of the styrene solution of sample C-1, and 50 parts by weight of calcium carbonate were added and thoroughly mixed to obtain a uniform resin composition. This resin composition 100
0.1 part by weight of cobalt octenoate and 0.5 part by weight of tertiary butyl peroxyoctoate were added and mixed uniformly as an impregnating agent, and glass roving was used as a reinforcing agent, and molded by filament winding method. The product was molded. The molded product obtained had excellent impact resistance and was free from cracks and color unevenness. In addition, no precipitation of calcium carbonate was observed in the resin composition before curing. Example 4 In Reference Example 7, instead of the styrene solution of Sample C-1, a modified block copolymer (Sample A molded article was molded in the same manner as in Reference Example 7 except that a styrene solution (referred to as C-5) was used. The obtained molded product had excellent impact resistance and good appearance. Incidentally, Sample C-5 was produced in the same manner as the modified block copolymer of Sample C-4, except that acrylic acid was used instead of maleic anhydride. The content of unreacted acrylic acid was 0.3% by weight. Comparative Example 13 Hydrogenating block copolymer B-1 using cobalt naphthenate and triethylaluminum as catalysts,
A block copolymer in which about 50% of the double bonds in the butadiene block portion were hydrogenated was synthesized as Comparative Example (i). Next, 3 parts by weight of maleic anhydride and 0.01 parts by weight of Perhexa 25B were uniformly mixed with 100 parts by weight of the block copolymer, and then maleated in the same manner as Sample C-4. The amount of maleic anhydride added to the obtained modified product was approximately 10/molecular polymer (referred to as sample F-1). Next, a cured product of the unsaturated polyester resin composition was obtained in the same manner as in Reference Example 3, and its heat aging resistance was examined and shown in Table 8. It is found that when a block copolymer with a hydrogenation rate of less than 80% is used, the dart impact strength after the heat aging resistance test is inferior. In addition, as Comparative Example 13(ii), block copolymer B-1
A cured product of an unsaturated polyester resin composition was prepared in the same manner as in Reference Example 3 using a block copolymer in which about 90% of the double bonds in the butadiene moiety were hydrogenated, but the composition was inferior in dart impact strength. It was hot.

【table】

Claims (1)

[Scope of Claims] 1 (a) unsaturated polyester resin (b) at least one vinyl aromatic compound polymer block A and at least one olefin compound polymer block B having a degree of unsaturation not exceeding 20%;
unique, and has a low content of vinyl aromatic compounds.
A modified block copolymer (c) in which one or more molecular units containing a carboxylic acid group or its derivative group are bonded to a block copolymer of 10 to 90% by weight per polymer molecule of the block copolymer. A composition comprising a vinyl monomer (d) and a curing agent, characterized in that the modified block copolymer (b) component contains 0.05 to 5% by weight of unreacted unsaturated carboxylic acid or a derivative thereof. A thermosetting unsaturated polyester resin composition.