JPH0252921B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a spherical polymer, and more specifically to glycidyl acrylate or glycidyl methacrylate (hereinafter referred to as "G(M)A").
This invention relates to a method for producing a spherical polymer containing bonded epoxy groups by subjecting it to aqueous suspension polymerization under specific conditions in the presence of a specific water-soluble polymer. Conventionally, raw materials for molding have been easy to handle, such as pellets, flakes, small spheres, and fine particles, and it is sometimes convenient to prepare granular polymers from the beginning. There are many application fields where the particle shape itself is required, such as gels and lubricants. Furthermore, polymers containing bonded epoxy groups have the possibility of being applied to various fields of use by introducing various functional groups depending on their reactivity. discloses a technique for producing immunoactive fine particles by reacting G(M)A polymer fine particles with an immunoactive substance having an amino group. According to this publication, polymerization is carried out in a medium that dissolves the monomers but precipitates the produced polymer, and that depending on the monomer composition and selection of the polymerization medium, 0.03
Although it is stated that fine particulate G(M)A polymer of ~10μ can be obtained, this method uses an organic solvent for the polymerization medium, washing, etc., so it is difficult to operate on an industrial scale due to odor etc. There are many points to keep in mind from an environmental and safety perspective. Furthermore, in application fields such as gels for liquid chromatography and ion exchange resins, particle sizes of 20 to 1000 μ are usually used, and there is a need for an industrial means for producing spherical polymers with such particle sizes. . Also, Journal of the Chemical Society of Japan, 1979, (12), p.1756~
1759 discloses a method for producing a GMA spherical polymer as a substrate for producing a chelating ion exchange resin, but in order to obtain a spherical polymer, large amounts of sodium sulfate and calcium carbonate are used as dispersants along with gelatin. In order to decompose and remove calcium carbonate from the produced polymer, complicated operations such as adding hydrochloric acid and washing with hot water are required. Here, the present inventors have discovered that epoxy group-containing polymers have various reactivities derived from epoxy groups, and the resulting polymer particles are generally highly sticky and easily aggregate and coalesce into sticky lumps. As a result of extensive research into industrially advantageous production of aggregated granular particles, the desired particle size can be achieved by using a specific water-soluble polymer as a dispersant and carrying out aqueous suspension polymerization under specific pH and stirring conditions. The inventors have discovered that it is possible to produce spherical polymers by industrial means, and have arrived at the present invention. That is, an object of the present invention is to provide an industrial method for producing spherical polymers containing bonded epoxy groups and having various reactivities. The object of the present invention is to use GA or GMA alone or a monomer mixture consisting of 50% by weight or more of the above monomer and the balance of at least one other monomer,
A water-soluble polymer and an oil-soluble radical polymerization initiator containing a monomer unit consisting essentially of an ethylenically unsaturated carboxylic acid or a salt thereof bonded to a monomer unit consisting of an ethylenically unsaturated sulfonic acid or a salt thereof in the presence of PH2-9 and stirring speed 50-500r.pm
This can be achieved by aqueous suspension polymerization under the following conditions. The present invention will be explained in detail below. First, as a monomer, G(M)A alone or 50% by weight or more, preferably 60% by weight or more of G(M)A
It is necessary to use a monomer mixture consisting of the following monomers and the balance being at least one other monomer. Other monomers may be used without any limitation as long as they are copolymerizable with G(M)A, such as vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride, etc. Vinyl halides and vinylidene halides; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, and their salts; methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, acrylic acid Acrylic esters such as methoxyethyl, phenyl acrylate, and cyclohexyl acrylate; Methacrylic esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, methoxyethyl methacrylate, phenyl methacrylate, and cyclohexyl methacrylate unsaturated ketones such as methyl vinyl ketone and methyl isopropenyl ketone;
vinyl formate, vinyl acetate, vinyl propionate,
Vinyl esters such as vinyl butyrate and vinyl benzoate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; acrylamide and its alkyl substituted products; Saturated hydrocarbon sulfonic acids and their salts; styrene, α-methylstyrene,
Styrene and its alkyl or halogen substituted products such as chlorostyrene; allyl alcohol and its esters or ethers; basic vinyl compounds such as vinylpyridine, vinylimidazole, dimethylaminoethyl methacrylate; acrolein, methacrolein, vinylidene cyanide, methacrylate Examples include vinyl compounds such as lonitrile. In addition, divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, N,
By using crosslinking monomers such as N′-methylenebisacrylamide, divinyl succinate, diallyl succinate, vinyl methacrylate, allyl methacrylate, triallyl cyanurate, and triallyl isocyanurate, polymers can be actively It can also be crosslinked. Next, a method for polymerizing the monomer will be described. First, the water-soluble polymer to be present in the polymerization system, which is a particularly important component for achieving the purpose of the present invention, includes a monomer unit (component A) consisting essentially of an ethylenically unsaturated carboxylic acid or a salt thereof. It is necessary to use a water-soluble polymer containing a monomer unit consisting of an ethylenically unsaturated sulfonic acid or a salt thereof (component B), and finally a water-soluble polymer containing both components A and B. Although polymers obtained by any method can be effectively used in the present invention, generally components A and B are copolymerized by a well-known method (in particular, by using water as a polymerization medium). (solution polymerization). In addition, component A may be introduced into the polymer by hydrolyzing a copolymer of unsaturated carboxylic acid esters such as esters of acrylic acid or methacrylic acid, or by sulfonation of the polymer. Needless to say, methods such as introducing the B component using the same method can also be adopted. In addition, the composition ratio of component A and component B in such a water-soluble polymer varies slightly depending on the copolymerization ratio of G(M)A and the types of other monomers, and it is difficult to define it uniquely. However, generally A component/B component =
It is desirable that the polymerization degree be in the range of 30 to 80%/70 to 20%, and there is no particular restriction on the degree of polymerization of such a polymer, but within a practical molecular weight range, it is better to use one with a small molecular weight to form dispersed particles. This seems to be preferable in terms of the effect of preventing coalescence. Depending on the type of other monomers, water-soluble polymers may be prepared by copolymerizing or graft-polymerizing a small amount of a hydrophobic monomer such as vinylidene chloride in addition to components A and B. In some cases, better spherical polymers can be obtained by using such polymers, and therefore such polymers are also included in the scope of the water-soluble polymers used in the present invention. In addition, A introduced into such water-soluble polymers
Ingredients include unsaturated monocarboxylic acids and their salts such as acrylic acid, methacrylic acid, vinyl acetic acid, and crotonic acid; unsaturated polycarboxylic acids such as maleic acid, fumaric acid, itaconic acid, aconitic acid, citraconic acid, and mesaconic acid. Among these, monomer units consisting of methacrylic acid and its salts are recommended from the viewpoint of forming spherical polymers. In addition, as component B, sulfonated styrene,
Sulfonated unsaturated hydrocarbons such as allylsulfonic acid and methallylsulfonic acid and their salts; sulfoalkyl esters of acrylic acid or methacrylic acid such as methacrylic acid sulfoethylene ester and methacrylic acid sulfopropyl ester and their salts, etc. can be mentioned. The amount of water-soluble polymer used is as follows:
It is desirable to use 5% by weight or more based on the monomer. In addition, along with the water-soluble polymer, the degree of polymerization is 500~
Particularly good results are obtained when polyvinyl alcohol (PVA) having a saponification degree of 85 to 95% is used in an amount of 0.1 to 5% by weight based on the monomer. Furthermore, examples of the oil-soluble radical polymerization initiator include the following azo compounds or organic peroxides. For example, azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methyl-valeronitrile), 2,2'-azobis(2,4-dimethylbutyronitrile), ( 2,
2'-azobis(2-methylcapronitrile), 2,
2'-azobis(2,3,3-trimethylbutyronitrile), 2,2'-azobis(2,4,4-trimethylvaleronitrile), 2,2'-azobis(2,
4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-ethoxyvaleronitrile), 2,2'-azobis(2,4-dimethyl-
4-n-butoxyvaleronitrile) etc. can be used, and as the organic peroxide, for example,
Acetyl peroxide, propionyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexamethyl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, - Diacyl peroxides such as 2-ethylhexyl peroxydicarbonate; t-butylperoxyisobutyrate, t-
Peroxy esters such as butyl peroxypivalate, t-butyl perocineodocanoate, t-butyl peroxylaurate, etc. can be used. Of course, two or more of the above oil-soluble radical polymerization initiators can also be used in appropriate combination.
Among these, azo compounds are preferred in terms of handling safety and performance, with 2,2'-azobisisobutyronitrile or 2,2'-azobis(2,4-dimethylvaleronitrile) being particularly preferred. Although it is difficult to define the amount of the initiator used, it is generally 0.2 to 2.0 based on the monomer weight.
Used within the range of %. In addition, regarding the pH of the polymerization system, if the acidity is too strong, ring opening of the epoxy group will occur during polymerization, and if the alkalinity is too strong, it will cause hydrolysis of the produced polymer, so the pH is 2 to 9, preferably 2 to 7. It is necessary to set it within the range of . Furthermore, the stirring conditions, which play an important role in adjusting the particle size, need to be changed depending on the shape of the blades, the presence or absence of baffles, the desired particle size, etc., and are difficult to define unambiguously. Approximate stirring speed
It is necessary to set it within the range of 50 to 500 rpm. In addition, as for the shape of the blade, a paddle shape or a turbine blade is suitable because it is easy to obtain a uniform particle size distribution. The polymerization temperature depends on the type of initiator, but the higher the temperature, the more likely the ring-opening reaction of the epoxy group will occur, or a portion of the monomer will be emulsified and emulsion polymerization will occur, producing a latex-like fine polymer. To avoid this problem, a temperature range of approximately 80°C or lower, preferably 40 to 70°C, is recommended. Although it is desirable to use industrial water as the polymerization medium, there is no problem in coexisting a water-miscible organic solvent or an electrolyte salt. By employing the method of the present invention described above, it is possible to selectively form a spherical polymer with a particle size of approximately 10μ or more, and the polymer has a gel moisture content of 20% or less, but is insoluble in solvents. From this fact, it is presumed that some of the epoxy groups are ring-opened and a crosslinked structure is introduced together with the hydrophilic group. As mentioned above, while it has a variety of reactivities derived from epoxy groups and can be applied to a variety of industrial fields, the produced polymer particles generally have strong stickiness and cause agglomeration and coalescence, resulting in sticky clumps. A noteworthy effect of the present invention is that spherical particles of an epoxy group-containing polymer that are easily converted can be produced by industrial means. EXAMPLES The present invention will be described in more detail by way of Examples below, but the scope of the present invention is not limited in any way by the description of these Examples. In the examples, parts and percentages are expressed on a polymerization basis unless otherwise specified. The gel moisture content is determined by centrifuging polymer particles that have been sufficiently equilibrated with deionized water.
After removing the water attached to the particle surface by centrifuging at 2000G, the weight (W ₁ ) of the polymer particles was measured, and then the polymer particles were dried and the dry weight (W ₂ ) was measured. It was calculated using the formula. Gel moisture content = W ₁ − W ₂ / W ₂ × 100 (%)

[Table] From the above table, even if the remaining constituent requirements satisfy the means of the present invention, if the stirring conditions are outside the recommended range of the present invention (No. and), a good spherical polymer cannot be formed. The fact that there is no such thing is clearly understood.

Claims (1)

[Scope of Claims] 1. Glycidyl acrylate or glycidyl methacrylate alone or a monomer mixture consisting of 50% by weight or more of the above monomer and the remainder of at least one other monomer, which is substantially ethylenically unsaturated. In the presence of a water-soluble polymer containing a monomer unit consisting of a carboxylic acid or a salt thereof and a monomer unit consisting of an ethylenically unsaturated sulfonic acid or a salt thereof, and an oil-soluble radical polymerization initiator, the pH is 2 to 9. 1. A method for producing a spherical polymer, characterized by carrying out aqueous suspension polymerization at a stirring speed of 50 to 500 rpm. 2. The manufacturing method according to claim 1, wherein the water-soluble polymer is used in an amount of 5% by weight or more based on the monomer. 3. The manufacturing method according to claim 1, wherein polyvinyl alcohol having a degree of polymerization of 500 to 2000 and a degree of saponification of 85 to 95% is present. 4. The manufacturing method according to claim 1, wherein the polymerization is carried out at a temperature of 80°C or lower.