JPH04185645A - Polymer bead and its production - Google Patents

Abstract

PURPOSE:To obtain a polymer bead excellent in light resistance, elasticity, abrasion resistance, impact resistance and mechanical strengths by using a polyurethane-poly(meth)acrylate obtained by reacting a composition comprising a plurality of specified substances in an aqueous suspension. CONSTITUTION:The title bead comprises a polyurethane-poly-(meth)acrylate obtained by reacting a composition comprising a polyisocyanate prepolymer (e.g. a compound obtained by reacting Adeka Polyether G-700, a product of AsahiDenka Kogyo K.K.) with hexamethylene diisocyanate, a (meth)acrylate monomer (e.g. methyl methacrylate) and a radical polymerization initiator (e.g. t-butyl peroxypivarate).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to polymer beads with excellent light resistance, elasticity, abrasion resistance, impact resistance, and mechanical strength, and a method for producing the same. . These polymer beads are very useful as organic fillers and additives in paints, plastics, adhesives, and cosmetics. Thermoplastic type beads are also useful as hot melt adhesives.

[Conventional technology]

Conventionally, acrylic beads, polystyrene beads, nylon beads, polyurethane beads, etc. have been known as polymer beads. Acrylic beads and polystyrene beads have the disadvantage that they are hard and brittle, and polystyrene beads also have a problem with light resistance. Nylon beads have poor water resistance. Polyurethane beads have excellent elasticity, but because they use isocyanate, there are still problems with light resistance.

[Problems to be solved by the invention] Therefore, the problems to be solved by the present invention are to improve light resistance, elasticity, abrasion resistance,
It is an object of the present invention to provide polymer beads having excellent impact resistance, water resistance, and mechanical strength, and a method for producing the same.

[Failure to solve the problem]

In order to solve this problem, the present invention consists of a polyisocyanate prepolymer, a (meth)acrylate monomer, a monomer copolymerizable with the monomer, and a radical polymerization initiator in water containing a suspension stabilizer. The composition is added, the stirring speed is adjusted to obtain a suspension with the desired particle size, and the reaction is initiated by heating to form polymer beads made of polyurethane-poly(meth)acrylate copolymer. A method is adopted in which the product is produced, solid-liquid separated, washed, and dried. As a result, polymer beads with a narrow distribution width and arbitrary particle size can be obtained.

In addition, these polymer beads have excellent light resistance, elasticity, abrasion resistance, impact resistance, water resistance, and mechanical strength.
In this production method, the particle size can be arbitrarily set within a wide range depending on the amount, type, and stirring speed of the suspension stabilizer, and the particle size distribution width can also be narrowed.

The present invention will be explained in detail below.

The polyisocyanate prepolymer referred to in the present invention refers to isocyanate, puree 1. This refers to the reaction product of diisocyanate and polyol, which are commonly used as raw materials for polyurethane resin, and has a terminal isocyanate group.
Any type of acrylic polyol may be used, and the type of isocyanate is selected depending on the desired physical properties, regardless of whether it is a yellowing type, a non-yellowing type, or a non-yellowing type. Moreover, their combined use is also possible.

What is the (meth)acrylate monomer referred to in the present invention (meth)?
Refers to acrylic acid esters and nitrile derivatives, specifically methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t -Butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, 2-
Ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, 2-methquinethyl (meth)acrylate, 2-
Ethoxyethyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate Acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol di(meth)
Acrylate, l,6 hexanediol di(meth)acrylate, ethylene oxide modified bisphenol A di(meth)acrylate, propion oxide modified bisphenol hene(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide modified trimethylolpropane (meth)acrylate, pentaerythritoltri(meth)acrylate,
Examples include pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, allyl(meth)acrylate, and (meth)acrylic acid.

Monomers that can be copolymerized with the (meth)acrylate include organic acid vinyl esters, unsaturated acid esters, benzene derivative monomers, and others.

Examples of organic acid vinyl esters include vinyl acetate, vinyl propionate, vinyl versatate (trade name: Beoba, Shell Chemical), and the like. Examples of unsaturated acid esters include maleic esters, fumaric esters, and itaconic esters. Examples of benzene derivative molecules include styrene, p-methylstyrene, divinylbenzene, and vinylpyridine. Other examples include acrylonitrile, vinyl chloride, (meth)acrylamide, phenylmaleimide, cyclohexynormaleimide, tetraallyloquinethane, triethyleneglyfur divinyl ether, and the like. These monomers can be used as a mixture of one or more types in any ratio.

The radical polymerization initiator used in the present invention may be one that generates radicals when using heavy metals, such as benzoyl peroxide, t-butyl benzoate, lauroyl peroxide, m-tolyl peroxide, diisopropyl peroxydicarbonate, t- -Butyl peroxyne piperate, cumyl peroxy neodecanoate, t-butyl peroxy 2-ethylhexanoate, octanoyl peroxide, decanoyl peroxide, -butyl peroxy 2-ethyl hexanoate, t-butyl peroxy organic peroxides such as ruperoxyisopropylcarbofluorite, cumylperoxyoctaate, 2.2azobisisobutyronitrile, 2.2azobis(2,4dimethylvaleronitrile), 1.1azobis(cyclo Examples include azo compounds such as 1-carbonitrile, but are not limited thereto, and a combination of these can also be used.

The suspension stabilizer used in the present invention refers to those commonly used in suspension polymerization, and may be organic or inorganic. Specifically, methylcellulose, hydroxyethylcellulose,
Cellulose water-soluble resins such as hydroquinopropyl methylcellulose and carboxin methylcellulose, polyvinyl alcohol, polyacrylates, polyethylene glycol, polyvinylpyrrolidone, polyacrylamide,
There are tertiary phosphates, which may be used in combination depending on the purpose.

In the present invention, the suspension stabilizer is a polyisone urethane prepolymer, a (meth)acrylate monomer, or a monomer copolymerized with this monomer, hereinafter referred to as a copolymerized monomer. ) 0.01 to 200 per 100 parts by weight of the total amount of
parts by weight, polyisocyanate urethane prepolymer dissolved or dispersed in 100-1000 parts by weight of water,
A composition consisting of a (meth)acrylate monomer or a comonomer thereof, and a radical polymerization initiator is added, and the stirring speed is adjusted so as to obtain a predetermined particle size. After particle size adjustment is completed, the temperature is raised to 30-90°C and reacted for 1-4 hours.
Thereafter, the suspension stabilizer adhering to the beads is removed by cooling, solid-liquid separation, washing, and drying to obtain polymer beads.

Further, the blending amount of the (meth)acrylate monomer is preferably in the range of 25 to 400 parts by weight based on 100 parts by weight of the polyisocyanate urethane prepolymer, and the blending amount of the copolymer monomer when using it is preferable. It is desirable that the amount is about 20 to 80% by weight of the total amount with the (meth)acrylate monomer. A pigment or a diluting solvent may be added in advance to the composition consisting of a polyisocyanate prepolymer, a (meth)acrylate monomer or a comonomer thereof, and a radical polymerization initiator.

The pigment used here may be any pigment as long as it does not inhibit this reaction, and may be one that reacts with the inner atom.

The diluting solvent may be any solvent as long as it is compatible with the composition comprising the polyisocyanate urethane prepolymer, the (meth)acrylate polymer or its comonomer, and the radical polymerization initiator and does not inhibit this reaction. In addition, a composition consisting of a polyisocyanate urethane prepolymer, a (meth)acrylate monomer or a comonomer thereof, and a radical polymerization initiator is added to improve the physical properties of polymer beads, as well as an ultraviolet absorber and an antioxidant. Agents may also be added.

The stability of the suspension system is determined by the type and amount of the suspension stabilizer, the composition of the polyisocyanateurethane brevolomer used, the (meth)acrylate monomer or comonomer thereof, and the radical polymerization initiator. It depends on the composition of the product, and in general, as the amount of Qi9 stabilizer increases, the stability increases, but the particle size tends to decrease, and the viscosity of the suspension increases, making solid-liquid separation and cleaning difficult. If the amount of suspension stabilizer is too small, particles tend to coagulate among themselves, and particles with small diameters cannot be obtained. Therefore, the suspension stabilizer is suitably used in an amount of 1 to 30 parts by weight based on 100 parts by weight of the composition comprising the polyisocyanate prepolymer, the (meth)acrylate monomer or a comonomer thereof, and the radical polymerization initiator.

After the reaction is complete, enzymes such as cellulolytic enzymes and reagents such as hypochlorite that decompose suspension stabilizers are used to reduce the viscosity of the suspension to facilitate solid-liquid separation and to facilitate cleaning. The suspension may be treated with, etc.

The present invention will be explained in detail below using examples, but the invention is of course not limited to these examples.

Synthesis Example 1 Adeca polyether G-700 (hydroxyl value 225 m
g/KOHg)*' 748 g and 1008 g of hexamethylene diison atomite (hereinafter referred to as HMDI) were charged, and after sufficient upward displacement with nitrogen gas, the mixture was sealed and stirred at 120°C for 20 hours.・Mixed and reacted. Thereafter, unreacted HMD I was removed under reduced pressure, and toluene was added to obtain a compound (1) with a nonvolatile content of 90% by weight.

This product has an isocyanate content of 8.73% and a viscosity of 15.
00 cps (25°C).

*I: Asahi Denka Kogyo Co., Ltd. product (Glyrelin PO adduct) Synthesis Example 2 In the same manner as Synthesis Example 1, 854 g of Plaxel-308 (hydroxyl value 197 mg/KOHg) and HMDI 1
008g was reacted to obtain a compound (n) which was a toluene solution with a nonvolatile content of 90% by weight. This product had an isocyanate content of 8.10% and a viscosity of 850 cps (25°C).

*! : Daicel Chemical Industries, Ltd. product (trimethylolpropane caprolactone adduct) Synthesis Example 3 Plaxel-208 (hydroxyl value 138 mg /
3,813 g of KOHg) and 444 g of inphorone diisocyanate (hereinafter referred to as IPDI) were prepared.
Furthermore, after upward displacement with nitrogen gas, it was sealed and heated to 120℃.
The mixture was stirred and mixed for 20 hours to react. 80° after completion of reaction
After cooling, 539 g of toluene was added, stirred and mixed until homogeneous, and then cooled to obtain a compound (III).

This product has an isocyanate content of 462% and a viscosity of 230.
g (25°C).

*3 Daicel Chemical Industries, Ltd. product (trimethylolpropane caprolactone adduct) Synthesis Example 4 In the same manner as Synthesis Example 1, 1002 g of Niraporan 981 (hydroxyl value 112 mg/KOHg) *' and 5350 g of Dismodur W* were reacted. , non-volatile content 70% by weight
A toluene solution of compound (IV) was obtained. This one has an isocyanate content of 1.43% and a viscosity of 2150 cp.
s (25°C).

*4: Nippon Polyurethane Industries Co., Ltd. product (1°6 hexane polycarbonate diol) *5: Sumitomo Bayer Urethane Co., Ltd. product (dicyclohexyl/rumethane diiso 7
A) Synthesis Example 5 In the same manner as in Synthesis Example 1, Kurabol P-2010 (hydroxyl value 56 mg/KOHg) *' was converted to 7208 and IPDI
54 g was reacted to obtain a compound (V) which is a toluene solution with a non-volatile content of 70% by weight.

This product has a hydroxyl group content of 0.37% and a viscosity of 570 cp.
s (25°C).

*6: Kuraray Co., Ltd. product (ester of 3-methyl-1,5-bentanediol and adipic acid) Example 1 1000 g of water was placed in a 2L separable flask with a stirrer, and 5 g of Hemetrose 90SH-100*' was dissolved in it. to create a dispersion medium. While stirring the dispersion medium at 550 rpm, 150 g of compound (1), 150 g of methyl methacrylate, 16.7 g of toluene, barbutyl PV
*Add a solution consisting of @1.5g to create a suspension.

The temperature of the suspension was raised to 55°C with continuous stirring, and after reacting for 4 hours, the temperature was raised to 100"C to azeotropically separate toluene. After that, it was cooled to room temperature, solid-liquid separation was carried out, and the suspension was heated with water. Wash thoroughly,
Polymer beads were obtained by drying at 70°C for 20 hours. The beads had an average particle size of 60 μm and did not dissolve even when immersed in toluene overnight at room temperature.

*7: Shin-Etsu Chemical Co., Ltd. product: Methyl cellulose *8: Nippon Oil & Fats Co., Ltd. product; t-butyl baroxypipalate Example 2 1000 g of water was placed in a 2L separable flask with a stirrer, and 710 g of Hemetrose 90SH-100* was added to the flask.
Dissolve to create a dispersion medium. The dispersion medium was heated to 55 Orpm.
While stirring, 150 g of compound (1), 150 g of methyl methacrylate, 16.7 g of toluene, and barbutyl PV*"
A solution consisting of 1.5 g is added to create a suspension. The temperature of the suspension was raised to 55 °C with continuous stirring, and after reacting for 4 hours, 1 g of No Idesco AS-80* was added, stirred for 0.5 hours, and the temperature was raised to 100 °C over 1 hour. , at this temperature toluene was separated azeotropically. Then cool to room temperature,
Solid-liquid separation was performed, thoroughly washed with water, and then dried at 70°C for 20 hours to obtain polymer beads.

The average particle diameter of these beads was 30 to 35 μm, and they did not dissolve even when immersed in toluene overnight.

*9: Rakuto Kasei Kogyo Co., Ltd. product: Cellulose degrading enzyme Example 3 In Example 2, the amounts of Metrose 90SH-100*7 and Hidesco AS-80* were 20g and 20g, respectively.
g, and other conditions are the same, the average particle size is 1.
Polymer beads of 5 μm were obtained. The beads did not dissolve even after soaking in toluene overnight.

Example 4 In Example 2, the usage amounts of Metrose 90SH-100*7 and Hidesco AS-80*' were 30g and 30g, respectively.
g, and other conditions are the same, the average particle size is 1.
Polymer beads of 0 μm were obtained. The beads did not dissolve even after soaking in toluene overnight.

Example 5 1000 g of water is charged in a separable flask equipped with a 2Lfi stirrer, and 5 g of Hemizunol 201*" is dissolved in the water to create a dispersion medium. The dispersion medium is stirred at 55 Qrpm and replaced with nitrogen while compound (II) is added. 90g, allyl methacrylate 10.5g, methyl methacrylate 12
6g, n-butyl methacrylate 63g, styrene 1
o, 5g,) 10g of toluene, barbutyl PO*”4.2
Add a solution consisting of g to create a suspension. The temperature of the suspension was raised to 60'C with continuous stirring, and after reacting for 5 hours, 5%
After adding 2.5 g of sodium hypochlorite aqueous solution and raising the temperature to 80"C and holding it for 1 hour, the temperature was raised to 100 °C over 1 hour.
At this temperature toluene was separated azeotropically. After that, it was cooled to room temperature, separated into solid and liquid, and washed thoroughly with water.
C. for 20 hours to obtain polymer beads. The beads had an average particle size of 55 μm and did not dissolve even when immersed in dimethylformamide overnight at room temperature.

*10: Unitika Co., Ltd. product: modified polyvinyl alcohol.

Example 6 A 2L separable flask equipped with a stirrer is charged with 1000 g of water, and Hemizunol 20111010 g is dissolved therein to create a dispersion medium. While stirring the dispersion medium at 55 Qrpm, 90 g of compound (I) and 10.5 g of allyl methacrylate were added.
g, methyl methacrylate) 136.5g, n-butyl methacrylate 63g, )ru m71Qg, barbutyl o*542g, Regime Color White CBA
A composition consisting of 55 g of -522M*■ is added to form a suspension. While stirring, the atmosphere was replaced with nitrogen and the suspension was heated to 60°C.
After reacting for 5 hours, 2.5 g of a 5% sodium hypochlorite aqueous solution was added and the temperature was raised to 80°C. After holding for 1 hour, the temperature was raised to 100'C over 1 hour, and toluene was separated azeotropically at this temperature. Then cool to room temperature,
Solid-liquid separation was carried out, thoroughly washed with water, and then dried for 70 hours in Cl2O to obtain white polymer beads. The average particle diameter of these beads was 32 μm, and they did not dissolve even when immersed in dimethylformamide overnight.

White pigment Examples 7 to 9, manufactured by Mokume Regime Color Kogyo Co., Ltd. Colored polymer beads were obtained in Example 6, except that the pigment used was changed to the one shown below, and the other conditions were the same. The average particle size of these beads is 30 to 35 μm, and they are immersed in dimethylformamide overnight to produce Mosol*13, a product of Renno Color Industries Co., Ltd.; Brown Pigment*I4. Resino Color Industries Co., Ltd. Product/Yellow Pigment Example 10 Cef XH Rubble Flask with 2L Stirrer (1000ml
Prepare g, and in this hair long A-20P (X) * I
55 g, Alcox E-60*1@0.5 g, 0.5 g of dodecylbenzenesulfonic acid So9, and 20 g of sodium chloride are dissolved to prepare a dispersion medium.The dispersion medium is stirred at 600 rpm to prepare a dispersion medium. (I) 30g, butyl acrylate 54g, methyl methacrylate 20g
2.5g, ) 13.5'g, ) 13.5'g, ) 2.7g, lauroyl peroxide
Add a solution consisting of g to create a suspension. While stirring and purging with nitrogen, the temperature was increased to 60°C for 2 hours to 70°C.
- Reacted for 2 hours. Next, the temperature was raised to 85°C, 1 g of potassium persulfate was added, and the mixture was maintained for 1 hour, cooled to room temperature, solid-liquid separated, and dried under reduced pressure at 70°C for 20 hours to obtain polymer beads. The average particle size of these beads is 100
μm did not dissolve even after overnight immersion in dimethylformamide.

*15: Toagosei Co., Ltd. product: Polyacrylate Wood grain: Meisei Chemical Co., Ltd. product: Polyethylene oxide Example 11 In Example 10, 707A-20P (X) *I5
A dispersion medium was prepared by changing the usage amount to 8g and keeping the other things the same. 30 g of the compound (1) was added to the dispersion medium.

Butyl acrylate 54g, methyl methacrylate-42
Add a solution consisting of 02.5 g, 13.5 g of NK ester IG*, and 2.7 g of benzoyl peroxide to create a suspension.While stirring and replacing the mixture with nitrogen, the temperature is raised.
The reaction was carried out at 60'C for 2 hours and at 70°C for 2 hours. Then, after raising the temperature to 85 ° C, 1 g of potassium persulfate was added,
After holding for 1 hour, cooling to room temperature and solid-liquid separation, 7
Polymer beads were obtained by drying at 0'C under reduced pressure for 20 hours.

The beads had an average particle size of 40 μm and did not dissolve even when immersed in dimethylformamide overnight.

*17: Product of Shin Nakamura Chemical Co., Ltd.; Ethylene glycol dimethacrylate Example 12 1000 g of water was charged into a 2L separable flask with a stirrer, and Hemetrose 90SH-100*'1Og was placed in it.
Dissolve to create a dispersion medium. The dispersion medium was heated to 55 Orpm.
While stirring, add a solution consisting of 214 g of the compound (■), 150 g of methyl methacrylate, and 3 g of nof-butyl PV*'' to create a suspension. While continuing to stir and replacing the mixture with nitrogen, the temperature was raised to 55°C. The reaction was then carried out for 4 hours.Next, No\IDESCO AS-80*'lg was added and stirred for 0.5 hours, then the temperature was raised to 100'C over 1 hour, and toluene was separated by azeotropy at this temperature. Thereafter, it was cooled to room temperature, separated into solid and liquid, thoroughly washed with water, and then dried at 70° C. for 20 hours to obtain polymer beads.

The beads have an average particle size of 30-35 μm, dissolve in dimethylformamide at room temperature, and have a melting temperature of about 150'C.
There was.

Example 13 Polymer beads were obtained in Example 2, except that 214 g of the compound (IV) was used instead of the compound (nl), and the other conditions were the same. The average particle size of these beads is 30~
It was 35 μm and dissolved in dimethylformamide at room temperature, with a melting temperature of about 130°C.

Example 14 In Example 13, 1.07 g of the compound (In) and 107 g of the compound (V) were used instead of the compound (IV),
Polymer beads were obtained under the same conditions. These beads had an average particle size of 30 to 35 μm, and were dissolved in dimethylformamide at room temperature, with a melting temperature of about 110°C.

〔Effect of the invention〕

As explained above, since the polymer beads of the present invention are made of polyurethane-poly(meth)acrylate, they have excellent light resistance, elasticity, abrasion resistance, impact resistance, and mechanical strength. .

Furthermore, according to the method for producing polymer beads, the particle size of the polymer beads can be easily adjusted, and beads with a narrow and uniform particle size distribution can be obtained.

Claims (1)

[Claims] 1. A polyurethane-poly(
Polymer beads made of meth)acrylate. 2. Polyurethane obtained by reacting a composition consisting of a polyisocyanate prepolymer, a (meth)acrylate monomer, a monomer copolymerizable with the monomer, and a radical polymerization initiator in an aqueous suspension system. Polymer beads made of poly(meth)acrylate copolymer. 3. A composition consisting of a polyisocyanate prepolymer, a (meth)acrylate monomer, and a radical polymerization initiator is dispersed in the form of particles in water containing a suspension stabilizer, and then the mixture is heated to react. A method for producing polymer beads made of polyurethane-poly(meth)acrylate by synthesizing polyurethane-poly(meth)acrylate, followed by solid-liquid separation, washing, and drying. 4. A composition consisting of a polyisocyanate prepolymer, a (meth)acrylate monomer, a monomer copolymerizable with the monomer, and a radical polymer initiator is made into particles in water containing a suspension stabilizer. The polyurethane-poly(meth)acrylate copolymer is synthesized by dispersing and then reacting by humidifying the polyurethane-poly(meth)acrylate copolymer, followed by solid-liquid separation, washing, and drying. A method of producing polymer beads consisting of coalescence. 5. A method for producing polymer beads made of polyurethane-poly(meth)acrylate according to the method according to claim 3, using a p-lysocyanate prepolymer having two isocyanate groups in one molecule. 6. A method for producing polymer beads comprising a polyurethane-poly(meth)acrylate copolymer according to the method according to claim 4, using a polyisocyanate prepolymer having two isocyanate groups in one molecule. 7. A method for producing polymer beads made of polyurethane-poly(meth)acrylate according to the method of claim 3, using a polyisocyanate prepolymer having three or more isocyanate groups in one molecule. 8. A method for producing polymer beads comprising a polyurethane-poly(meth)acrylate copolymer by the method according to claim 4, using a polyisocyanate prepolymer having three or more isocyanate groups in one molecule. 9. A method for producing polymer beads made of polyurethane-poly(meth)acrylate according to the method of claim 3, using a polyisocyanate prepolymer dissolved in an organic solvent. 10. A method for producing polymer beads comprising a polyurethane-poly(meth)acrylate copolymer according to the method of claim 4, using a polyisocyanate prepolymer dissolved in an organic solvent. 11. A method for producing colored polyurethane-poly(meth)acrylate polymer beads according to the method of claim 2, using a polyisocyanate prepolymer in which a pigment is dispersed and kneaded in advance. 12. A method for producing polymer beads comprising a colored polyurethane-poly(meth)acrylate copolymer according to the method of claim 3, using a polyisocyanate prepolymer in which a pigment is dispersed and kneaded in advance. 13. In the method of claim 3, after carrying out the reaction using a cellulose-based water-soluble polymer as a suspension stabilizer, the cellulose-based water-soluble polymer is decomposed using a cellulose-degrading enzyme to form a suspension. After reducing the viscosity, solid-liquid separation, washing,
A method for producing polymer beads made of polyurethane-poly(meth)acrylate by drying. 14. In the method of claim 4, after carrying out the reaction using a cellulose-based water-soluble polymer as a suspension stabilizer, the cellulose-based water-soluble polymer is decomposed using a cellulose-degrading enzyme to form a suspension. After reducing the viscosity, solid-liquid separation, washing,
A method for producing polymer beads made of polyurethane-poly(meth)acrylate copolymer by drying. 15. In the method of claim 3, after carrying out the reaction using a polyvinyl alcohol-based water-soluble polymer as a suspension stabilizer, the polyvinyl alcohol-based water-soluble polymer is reacted using hypochlorite. A method for producing polymer beads made of polyurethane-poly(meth)acrylate by decomposing and reducing the viscosity of a suspension, followed by solid-liquid separation, washing, and drying. 16. In the method of claim 4, after carrying out the reaction using a polyvinyl alcohol-based water-soluble polymer as a suspension stabilizer, hypochlorite is used to react the polyvinyl alcohol-based water-soluble polymer. After decomposition and reducing the viscosity of the suspension, solid-liquid separation, washing, and drying are performed to form polyurethane-poly(meth)
A method of producing polymer beads comprising acrylate copolymers.