JPH04146904A - Polymerization of glycidyl (meth)acrylate - Google Patents

Abstract

PURPOSE:To obtain gel-free organic solvent-soluble polymer particles by suspension-polymerizing glycidyl (meth)acrylate or a monomer mixture based thereon at a relatively low temperature-in the presence of a specified polymeriza tion initiator and a chain transfer agent. CONSTITUTION:Glycidyl (meth)acrylate or a monomer mixture containing at least 50wt.% or above glycidyl acrylate is suspension-polymerized in an aqueous system at 60 deg.C or below in the presence of a polymerization initiator having a 10-hr half-life temperature of 70 deg.C or below (e.g. diisopropyl peroxydicarbonate) and a chain transfer agent (e.g. t-dodecyl mercaptan). The obtained polymer particles have a high content of residual epoxy groups as compared with that of the glycidyl (meth)acrylate used. They can be desirably used in the fields of compatibilizers for polymer alloys, modifiers for synthetic resins, adhesives, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to glycidyl acrylate or glycidyl methacrylate [hereinafter, acrylic acid and methacrylic acid are collectively referred to as (
meth)acrylic acid] alone or as the main component of a monomer mixture. Relating to a method of manufacturing.

[Prior Art] Polymer particles containing epoxy groups are widely used in fields such as polymer alloy compatibilizers, plastic modifiers, and fiber modifiers. As a method for producing this polymer particle,
Japanese Patent Publication No. 52-3989 and Japanese Patent Publication No. 59-230
No. 008 discloses a production method using aqueous suspension polymerization. However, these methods produce gelled products and cannot produce polymer particles that are soluble in organic solvents.
9 (1964) describes that when homopolymerization of glycidyl methacrylate is carried out by a conventionally known method, the resulting polymer is insoluble in solvents.

[Problems to be Solved by the Invention] The present invention provides glycidyl (meth)acrylate homopolymer particles that do not form a gelled product, are soluble in organic solvents, and have a high residual rate of epoxy groups, or copolymer particles containing this as a main component. The purpose is to obtain polymer particles.

[11! Means for Solving the Problem] The present invention provides glycidyl (meth)acrylate or a monomer mixture containing 50% by weight or more of glycidyl (meth)acrylate, which has a 10-hour half-life temperature of 70°C or less. This is a polymerization method characterized by carrying out suspension polymerization in an aqueous system at 60° C. or lower in the presence of a polymerization initiator and a chain transfer agent.

In the present invention, other monomers that form a monomer mixture with glycidyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylate. ) Isobutyl acrylate, (meth)
t-butyl acrylate, dodecyl (meth)acrylate,
(meth)acrylic acid esters having an alkyl group having 1 to 22 carbon atoms, such as octadecyl (meth)acrylate and tocosyl (meth)acrylate; polypropylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate, etc. (meth)acrylic acid ester having a polyalkylene gelylcol group; (meth)acrylic acid,
Unsaturated monocarboxylic acids such as crotonic acid and their salts; unsaturated dicarboxylic acids such as fumaric acid and itaconic acid, their acid anhydrides and their salts; dimethyl fumarate, diethyl fumarate, di-n-butyl fumarate , diisobutyl fumarate, di-t-butyl fumarate, dimethyl itaconate, di-n-butyl itaconate, methylethyl fumarate, methyl-n-butyl fumarate, methylethyl itaconate,
Dicarboxylic acid esters such as ethyl-t-butyl itaconate; styrene derivatives such as styrene, α-methylstyrene, and chlorostyrene; vinyl halides and vinylidene halides such as vinyl chloride, vinyl bromide, vinyl fluoride, and vinylidene chloride; Unsaturated ketones such as methyl vinyl ketone and n-butyl vinyl ketone; Vinyl esters such as vinyl acetate and vinyl butyrate; Vinyl ethers such as methyl vinyl ether and n-butyl vinyl ether; Vinyl cyanides such as acrylonitrile, methacrylonitrile, vinylidene cyanide, etc. ;acrylamide and its alkyl-substituted amides;
Unsaturated sulfonic acids such as vinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid, P-styrenesulfonic acid, and salts thereof; vinyl compounds such as N-maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide; can be mentioned.

In the method of the present invention, it is necessary to use a polymerization initiator that performs the reaction at a temperature of 60° C. or lower and has a 10-hour half-life temperature of 70° C. or lower. When a polymerization initiator with a 10-hour half-life temperature higher than 70° C. is used, it is difficult to complete the polymerization reaction or to obtain polymer particles. Polymerization initiators with a 10-hour half-life temperature of 70°C or lower include:
Azo compounds, peroxy esters, peroxydicarbonates, dialkyl peroxides, diacyl peroxides, etc. can be used, such as 2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile) (10 hour half-life temperature 30.0°C) , 2.2-azobis(2-cyclopropylpropionitrile) (42.0°C), 2.
2-azobis(2,4-dimethylvaleronitrile) (51.0°C), 2.2-azobis(2-methylpropionitrile) (65.0°C), 2.2-azobis(2
-Methylbutyronitrile) (67).

), azo compounds such as dimethyl-2,2-azobis(2-methylpropionate) (66.0°C), t-butylperoxyvivalate (55.0°C), t-butylperoxyneodeca Noate (46°C), cumyl peroxyneodecanoate (36.6°C), t-hexylperoxyneodecanoate (44.7°C)
1-Butylperoxyneohexanoate (53.0
°C], t-hexylperoxyneohexanoate (51.3 °C), 1-hexyl peroxypivalate (53.2 °C), cumyl peroxyacetate (65 °C).
peroxyesters such as diisopropyl peroxydicarbonate (40.5°C), di-2-ethylhexyl peroxydicarbonate (43.4°C),
Di-n-propyl peroxydicarbonate (40.
5°C), cimilistyl peroxydicarbonate (same 4
0.9°C), acetylcyclohexylsulfonyl peroxide (26.5°C), di-2-ethoxyhexyl peroxydicarbonate (43°5°C), di(methoxyisopropyl)peroxydicarbonate (43.5°C).
5°C), peroxydicarbonates such as di(3-methyl-3-methoxybutyl) peroxydicarbonate (46.5°C), diimbutyperoxide (32.5°C)
), dialkyl peroxides such as di-3.5.5-)-
Listyl hexanoyl peroxide (59.5°C),
Dioctanoyl peroxide (62°C), dialkyl peroxide (62.0°C), dilauroyl peroxide (62.0°C), diacetyl peroxide (62.0°C),
68.0°C) and the like can be used. Of course, it is also possible to use two or more of the above polymerization initiators in combination. The amount of polymerization initiator used is based on the content of glycidyl (meth)acrylate in the monomer,
It is difficult to define it unambiguously because it varies depending on the type of monomer to be copolymerized, the target molecular weight, the reaction temperature, etc., but it is used in the range of 0.2 to 10% by weight based on the monomer. is preferred.

As the chain transfer agent used in the present invention, alkyl mercaptans, thioglycolic acid esters, mercaptopropionic acid esters, carbon tetrahalides, dimers of styrenes, etc. can be used, such as n-propyl mercaptan, isopropyl mercaptan, Alkyl mercaptans such as n-butyl mercaptan, isobutyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, thioglycolic acid esters such as butyl thioglycolate, octyl thioglycolate, methoxybutyl thioglycolate, β -Mercaptopropionate esters such as octyl mercaptopropionate and methoxybutyl β-mercaptopropionate, carbon tetrahalides such as carbon tetrachloride and carbon tetrabromide, 2゜4-diphenyl-4-methyl-1-pentene, etc. Examples include styrene dimers. Of course, 2 of the above chain transfer agents
It is also possible to use more than one type in combination. Although it is difficult to define the amount of the chain transfer agent used, it is preferably used in the range of 0.2 to 10% by weight based on the monomer. The use of the above chain transfer agent suppresses the formation of gelled products.

In the aqueous suspension polymerization in the present invention, the temperature is 60°C or less.
It is necessary to carry out the reaction preferably at a temperature of 50° C. or lower. It is not preferable to carry out the reaction at a temperature higher than 60° C. because side reactions will accelerate the gel formation reaction, and a portion of the resulting polymer will gel and become insoluble in organic solvents.

60°C in the presence of the above polymerization initiator and chain transfer agent.
The weight average molecular weight of the polymer particles that can be produced by carrying out the polymerization reaction at the following temperature is approximately 250°OOO or less.

In the present invention, the aqueous suspension polymerization reaction is carried out by a known method. First, water and a dispersant are placed in a reactor and stirred to dissolve or disperse the dispersant in the water. Next, a mixed solution of a monomer 1 polymerization initiator and a chain transfer agent is added and uniformly dispersed. Further, the air in the reaction system is replaced by introducing nitrogen. Then, the temperature is raised to the reaction temperature to start the polymerization reaction. Generally, the pH of the system during the reaction is preferably adjusted to a range of 4 to 9. After the reaction is completed, the reactant is taken out and filtered to isolate the produced polymer particles, which are then dried to obtain the product polymer particles.

As the dispersant, conventionally known ones can be used. That is, a combination of a solid inorganic powder and an anionic surfactant, a nonionic surfactant containing an oxyethylene group, gelatin, etc. can be used.

The dispersant is used in an amount of 0.01 to 2% by weight based on the total amount of monomers.

In addition, when carrying out suspension polymerization, the amount of monomer charged should be 5 to 50% by weight based on the total amount charged, and the stirring speed should be set to 50 to 45%.
By setting the speed to 0 rpm, polymerization can be completed in a stable dispersion state.

Furthermore, the shape of the blades of the stirrer is a turbine type or fardler type that produces a discharge flow, and the material of the reaction vessel is a stainless steel ring with electrolytic polishing or glass lining. As for the structure, one with a baffle plate or a draft tube can be used. Moreover, industrial tap water or deionized water can be used as the water that is the continuous phase in suspension polymerization. Furthermore, an inorganic salt such as sodium chloride may be added to the water to adjust the density difference between the water and the polymer particles, or a viscous substance such as glycerin may be added to the water to adjust the viscosity.

[Effects of the Invention] The polymer particles obtained by the method of the present invention are free of gelled substances;
It is soluble in organic solvents and has a high residual rate of epoxy groups relative to the glycidyl (meth)acrylate used. Therefore, the copolymer obtained by the method of the present invention is
It can be used in fields such as polymer alloy compatibilizers, synthetic resin modifiers, and adhesives.

[Example] The present invention will be explained below with reference to Examples. Parts and percentages in the examples are based on weight unless otherwise specified.

The weight average molecular weight was measured by gel permeation chromatography.

The epoxy group residual rate was determined as follows. First, produced polymer particles of known weight were dissolved in N,N-dimethylformamide, and then an excess amount of hydrochloric acid relative to the epoxy groups was added to this solution, and the mixture was allowed to react in a dark place for 1 hour with occasional stirring. After the reaction was completed, unreacted hydrochloric acid was titrated with an alkali, and the weight % A of epoxy oxygen in the polymer was determined from the amount of hydrochloric acid consumed. It was calculated from this value and the calculated weight %B of epoxy oxygen in the polymer using the following formula.

Epoxy group residual rate (%) = X100 Solubility in organic solvents was determined by dissolving polymer particles in various organic solvents of 9 times the weight and observing the solubility.

If the polymer particle solution has dissolved and become transparent, it is soluble, if some of the polymer particles have become insolubilized and precipitated in the solution, it is partially insoluble, and if most of the polymer particles have become insolubilized. Those that were swollen or precipitated in the solution were considered insoluble.

The average particle size of the polymer particles was determined as follows.

First, arbitrarily sampled polymer particles were uniformly placed on a glass plate and micrographs were taken.

Photographing was continued until the number of particles photographed reached 200 or more. The particle diameter of each particle on the photograph was measured and divided by the magnification ratio to obtain the actual particle diameter, and the obtained particle diameter was substituted into the following equation to obtain the average particle diameter.

D: Particle size of polymer particles (μm) n: Number of polymer particles with particle size Example 1 2.0 parts of tricalcium phosphate and 0.02 parts of sodium dodecylbenzenesulfonate were mixed with 792 parts of deionized water. The solution was placed in a polymerization reaction tank equipped with a stirrer equipped with one stage of six-blade turbine blades and four stainless steel baffles, and the stirring speed was adjusted to 20 rpm. Next, 4.0 parts of diisopropyl peroxydicarbonate and 4.0 parts of t-dodecyl mercaptan were dissolved in 198 parts of glycidyl methacrylate, and the solution was added to the polymerization reactor and dispersed for 30 minutes under a nitrogen atmosphere. Next, the temperature of the reaction system was raised to 45°C, and a polymerization reaction was carried out at a polymerization temperature of 45±1°C for 5 hours. After the reaction is complete, stop stirring, remove the reaction solution, and add the stock.
Polymer particles were isolated through a 50-mesh filter bag;
The sample was vacuum dried at 1°C for 24 hours.

Comparative Example 1 Polymer particles were obtained in the same manner as in Example 1 except that the polymerization temperature was 65±1° C. and 5.0 parts of dilauroyl peroxide was used instead of 4.0 parts of diisobutyl peroxydicarbonate.

Example 2 Polymer particles were obtained in the same manner as in Example 1, except that 10.0 parts of octyl thioglycolate was used instead of 4.0 parts of t-dodecylmercaptan.

Comparative Example 2 Polymer particles were obtained in the same manner as in Example 2, except that the polymerization temperature was 65±1° C. and 5.0 parts of dilauroyl peroxide was used instead of 4.0 parts of diisopropyl peroxydicarbonate.

Example 3 A solution of 4.0 parts of diisopropyl peroxydicarbonate and 10.0 parts of octyl β-mercaptopropionate dissolved in 198 parts of glycidyl methacrylate was prepared using a stirrer with one stage of six turbine blades and a stainless steel baffle plate 4.
The mixture was placed in a polymerization reaction tank equipped with a plate and stirred at 300 rpm. Next, a mixed dispersion of 2.0 parts of tricalcium phosphate, 0.02 parts of sodium dodecylbenzenesulfonate, and 792 parts of deionized water was added, and the mixture was stirred for 30 minutes under a nitrogen gas atmosphere. The polymerization reaction was carried out using 45 parts at 1° C. for 5 hours. Thereafter, polymer particles were obtained in the same manner as in Example 1.

Comparative Example 3 Polymer particles were obtained in the same manner as in Example 3 except that the polymerization temperature was 65±1° C. and 5.0 parts of dilauroyl peroxide was used instead of 4.0 parts of diisopropyl peroxydicarbonate.

Example 4 2.0 parts of tricalcium phosphate and 0.02 parts of sodium dodecylbenzenesulfonate were dissolved in 792 parts of industrial tap water and placed in a polymerization reaction tank equipped with a Fardler type stirrer and a stainless steel draft tube. , 25O
Stirred at rpm. To this, 198 parts of glycidyl methacrylate and 4 parts of diisopropyl peroxydicarbonate were added.
．． Add a solution containing 0 part of carbon tetrabromide and 4.0 parts of carbon tetrabromide, stir for 30 minutes under a nitrogen gas atmosphere, and then add 45 parts of carbon tetrabromide.
The polymerization reaction was carried out at ℃ for 5 hours. After the reaction was completed, polymer particles were obtained in the same manner as in Example 1.

Comparative Example 4 Polymer particles were obtained in the same manner as in Example 4, except that the polymerization temperature was 65±1° C. and 5.0 parts of dilauroyl peroxide was used instead of 4.0 parts of diisopropyl peroxydicarbonate.

Comparative Example 5 Polymer particles were obtained in the same manner as in Example 4 except that 4.0 parts of carbon tetrabromide was not used.

Example 5 A solution prepared by dissolving 1.0 part of tricalcium phosphate and 0.01 part of sodium dodecylbenzenesulfonate in 900 parts of ion-exchanged water was added to a polymerization reaction tank equipped with a Fardler-type stirrer and a stainless steel draft tube. and stirred at 300 ppm. Add to this 100 parts of glycidyl methacrylate and 5.0 parts of diisobutyl peroxide.
A solution containing 4.0 parts of t-dodecyl mercaptan and 4.0 parts of t-dodecyl mercaptan was added thereto and mixed for 30 minutes under a nitrogen gas atmosphere at a polymerization temperature of 35±1'C.

The polymerization reaction was carried out for 5 hours. After the reaction was completed, polymer particles were obtained in the same manner as in Example 1.

Example 6 At a polymerization temperature of 60±1° C., 5.0 parts of t-hexyl peroxyneohexanoate was used instead of diisopropyl peroxydicarbonate, and the amount of t-dodecyl mercaptan was changed from 4.0 parts to 3.0 parts. Polymer particles were obtained in the same manner as in Example 1 except for the following changes.

Example 7 A solution prepared by dissolving 2.0 parts of tricalcium phosphate and 0.02 parts of sodium dodecylbenzenesulfonate in 792 parts of industrial tap water was prepared using a stirrer with one stage of 6-blade turbine blades and a stainless steel baffle plate. 45 parts of glycidyl methacrylate was added to 198 parts of glycidyl methacrylate at 1°C under a stirring speed of 300 rpm and a nitrogen gas atmosphere.
2.4 parts of 2-azobis(4-methoxy-2,4-dimethylvaleronitrile) and 4.0 parts of t-dodecylmercaptan
A solution in which 1 part was dissolved was added dropwise over 1 hour, and the reaction was continued for an additional 2 hours. After the reaction was completed, polymer particles were obtained in the same manner as in Example 1.

Example 8 Example 1 except that the polymerization temperature was 5o±1°C and 3.0 parts of 2,2-azobis(2°4-dimethylvaleronitrile) was used instead of diisopropyl peroxydicarbonate.
Polymer particles were obtained in the same manner as above.

Comparative Example 6 Example 1 except that the polymerization temperature was 80±1°C, 3.6 parts of dibenzoyl peroxyte was used instead of 4.0 parts of diisopropyl peroxydicarbonate, and 4.0 parts of t-dodecylmercaptan was not used. Polymer particles were obtained in the same manner as above.

Comparative Example 7 Polymer particles were obtained in the same manner as in Example 1, except that the polymerization temperature was 80±1° C. and 3.6 parts of dibenzoyl peroxide was used instead of 4.0 parts of diisopropyl peroxydicarbonate.

Example 9 A solution of 4.0 parts of diisopropyl peroxydicarbonate and 2.0 parts of di-dodecyl mercaptan in a monomer mixture of 139 parts of glycidyl methacrylate and 59 parts of styrene was heated using a stirrer with 6 turbine blades and 1 stage. Place it in a polymerization reaction tank equipped with a machine and four stainless steel baffle plates.
It was stirred at 200 rpm. To this was added a mixed dispersion of 2.0 parts of tricalcium phosphate, 0.02 parts of sodium dodecylbenzenesulfonate, and 792 parts of deionized water, and after stirring for 30 minutes under a nitrogen gas atmosphere, S
The polymerization reaction was carried out at 0±1° C. for 5 hours. After the reaction is complete, 3
Isolate the polymer particles through a 50 mesh filter bag;
The polymer particles were vacuum dried at 1° C. for 12 hours to obtain polymer particles.

Comparative Example 8 Polymer particles were obtained in the same manner as in Example 9, except that the polymerization temperature was 65±1° C. and 5.0 parts of dilauroyl peroxide was used instead of 4.0 parts of diisopropyl peroxydicarbonate.

Example 10 Polymer particles were obtained in the same manner as in Example 9, except that the chain transfer agent was changed from 2.0 parts of t-dodecylmercaptan to 4.0 parts of carbon tetrabromide.

Comparative Example 9 At a polymerization temperature of 65±1°C, the initiator was changed from 4.0 parts of diisopropyl peroxydicarbonate to 5.0 parts of dilauroyl peroxide, and the chain transfer agent was changed from 2.0 parts of t-dodecylmercaptan to 4 parts of carbon tetrabromide. Polymer particles were obtained in the same manner as in Example 9 except that the amount was changed to .0 parts.

Comparative Example 10 Polymer particles were obtained in the same manner as in Example 9, except that the polymerization temperature was 50±1° C. and 2.0 parts of t-dodecylmercaptan, a chain transfer agent, was not used.

Example 11 Polymer particles were obtained in the same manner as in Example 9, except that the polymerization temperature was 35±1° C. and the initiator was changed from 4.0 parts of diisopropyl peroxydicarbonate to 5.0 parts of diisobutyl peroxide.

Example 12 Example 9 except that the polymerization temperature was 60±1°C and the initiator was changed from 4.0 parts of diisopropyl peroxydihydrobonate to 5.0 parts of t-hexyl peroxyneohexanoate.
Polymer particles were obtained in the same manner as above.

Example 13 At a polymerization temperature of 50±1° C., the initiator was changed from 4.0 parts of diisopropyl peroxydicarbonate to 2,2-azobis(4
-methoxy-2,4-dimethylvaleronitrile) 2.4
Polymer particles were obtained in the same manner as in Example 9 except that the amount was changed to

Example 14 At a polymerization temperature of 50±1°C, the initiator was changed from 4.0 parts of diisopropyl peroxydicarbonate to 2,2-azobis(2
Polymer particles were obtained in the same manner as in Example 9 except that the amount was changed to 3.0 parts (4-dimethylvaleronitrile).

Comparative Example 11 Polymer particles were obtained in the same manner as in Example 9, except that the polymerization temperature was 80±1° C. and 4.0 parts of dibenzoyl peroxide was used instead of 4.0 parts of diisopropyl peroxydicarbonate.

Example 15 The same procedure was carried out except that the composition of the monomer mixture was changed to 178 parts of glycidyl methacrylate and 20 parts of styrene, and the amount of the chain transfer agent t-dodecyl mercaptan was changed from 2.0 parts to 4.0 parts. Polymer particles were obtained in the same manner as in Example 9.

Comparative Example 12 The monomer composition was changed to 178 parts of glycidyl methacrylate and 20 parts of styrene, and 5.0 parts of dilauroyl perioside was used instead of 4.0 parts of diisopropyl peroxydicarbonate at a polymerization temperature of 65 ± 1°C. Polymer particles were obtained in the same manner as in Example 9, except that the amount of the aS-based motive agent dodecyl mercaptan used was changed from 2.0 parts to 4.0 parts.

Example 16 Same as Example 9 except that the monomer composition was changed to 139 parts of glycidyl methacrylate and 59 parts of methyl methacrylate, and the amount of initiator diisopropyl peroxydicarbonate was changed from 4.0 parts to 5.0 parts. Polymer particles were obtained.

Comparative Example 13 At a polymerization temperature of 65 ± 1°C, the composition of the monomer mixture was changed to 139 parts of glycidyl methacrylate and 59 parts of methyl methacrylate.
4. The initiator is diisopropyl peroxydicarbonate.
Polymer particles were obtained in the same manner as in Example 9, except that 0 part was changed to 0 part of dilauroyl peroxitro.

Example 17 Same as Example 9 except that the monomer composition was changed to 139 parts of glycidyl methacrylate and 59 parts of acrylonitrile, and the amount of the initiator diisopropyl peroxydicarbonate was changed from 4.0 parts to 5.0 parts. Polymer particles were obtained.

Comparative Example 14 The composition of the monomer body temperature liquid was 139 parts of glycidyl methacrylate,
Changed to 59 parts of acrylonitrile, polymerization temperature 65±1℃
Polymer particles were obtained in the same manner as in Example 9, except that the initiator was changed from 4.0 parts of diisopropyl peroxydicarbonate to 6.0 parts of dilauroyl peroxide.

Example 18 The monomer composition was changed to 139 parts of glycidyl methacrylate, 20 parts of styrene, 20 parts of methyl methacrylate, and 20 parts of acrylonitrile, and the amount of initiator diisopropyl peroxydicarbonate used was changed from 4.0 parts to 5.0 parts. Polymer particles were obtained in the same manner as in Example 9 except for the following.

Comparative example 15 Monomer composition: 139 parts of glycidyl methacrylate.

Example 9 except that 20 parts of styrene, 20 parts of methyl methacrylate, and 20 parts of acrylonitrile were used at a polymerization temperature of 65±1°C, and 6.0 parts of dilauroyl peroxide was used instead of 4.0 parts of diisopropyl peroxydicarbonate.
Polymer particles were obtained in the same manner as above.

Comparative Example 16 After dissolving 2.0 parts of tricalcium phosphate and 0.2 parts of sodium dodecylbenzenesulfonate in 792 parts of deionized water, they were placed in the same reaction vessel as in Example 1, and dibenzoyl was added to 198 parts of glycidyl methacrylate. peroxide 6.0
300p under nitrogen gas atmosphere.
Stir for 3 portions to disperse at pm. Next, a polymerization reaction was carried out for 72 hours at a polymerization temperature of 45 ± 1°C, but when stirring was stopped to take out the polymer particles, the sticky polymer aggregated into a lump. .

Comparative Example 17 Polymerization was carried out in the same manner as Comparative Example 16 except that 5.0 parts of 2,2-azobis(2-methylpropionitrile) was used instead of 6.0 parts of benzoyl peroxide, but the polymer particles When I stopped the stirring to take it out, the sticky polymer coagulated into a lump.

By comparing the Examples and Comparative Examples in Tables 1 and 2, suspension polymerization is carried out in an aqueous system at 60°C or lower in the presence of a polymerization initiator and chain transfer agent whose 10-hour half-life temperature is 70'C or lower. This shows that it is possible to produce polymer particles that are soluble in organic solvents and contain epoxy groups with a high residual rate relative to the glycidyl methacrylate used.

Claims (1)

[Claims] (1) Glycidyl acrylate or glycidyl methacrylate, or a monomer mixture containing 50% by weight or more of glycidyl acrylate or glycidyl methacrylate, is used as a polymerization initiator and chain transfer agent whose 10-hour half-life temperature is 70°C or lower. A polymerization method characterized by carrying out suspension polymerization in an aqueous system at 60°C or lower in the presence of.