JP2003012705A - Resin particle, method for producing the same and application of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain resin particles having strong hydrophilicity and excellent in dispersibility in aqueous media. SOLUTION: This method for producing the resin particles is to carry out a suspension polymerization of a hydrophobic polymerizable vinyl monomer in which an azo initiator having a repeating unit expressed by formula (I) (wherein R1, R2, R3 and R4 express each independently H, a lower alkyl or cyano; (m) express 1-500 integer; (n) express 1-200 integer) is dissolved in the presence of an amphoteric ionic surfactant in an aqueous medium.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the field of electronics such as LCD spacers, surface modifiers for silver salt films, film modifiers for magnetic tapes, thermal paper running stabilizers, rheology control agents, matting agents, etc. Chemicals such as paints, inks, adhesives, etc., medical fields such as particles for antigen-antibody reaction testing, cosmetics such as lubricants and extender pigments, low shrinkage agents for resins such as unsaturated polyester, paper, dental materials , An anti-blocking agent, a light diffusing agent, a resin modifier, and the like, which are applicable to general industrial fields, and to resin particles having excellent water dispersibility, a method for producing the same, and uses thereof.

[0002]

2. Description of the Related Art Conventionally, resin particles whose surface has been coated with a hydrophilic polymer have been produced by emulsion polymerization. In this emulsion polymerization, the polymerizable vinyl monomer is added to the resin particles which are the cores through the aqueous phase, and the polymerization reaction proceeds to generate resin particles larger than the resin particles as the cores. Therefore, in emulsion polymerization, the sequential addition of a polymerizable vinyl monomer has the advantages of improving the polymerization stability and easily removing the reaction heat. In the emulsion polymerization, when a hydrophilic polymerizable vinyl monomer is added to the polymerization system in the latter stage of the polymerization, resin particles having a hydrophilic surface are easily produced. Utilizing this polymerization method, the affinity between the resin particles as the core and water is improved, or a reactive functional group is introduced into the resin particles as the core.

However, in emulsion polymerization, it is difficult to industrially produce resin particles having a particle size of 1 μm or more, which are useful as a light diffusing agent, an antiblocking agent, and the like. On the other hand,
In suspension polymerization, usually, all the polymerizable vinyl monomers are charged into a polymerization vessel, the polymerizable vinyl monomers are mixed and dispersed in water, and the generated droplets of the polymerizable vinyl monomer are polymerized to obtain resin particles. Therefore, when the polymerizable vinyl monomer including the hydrophilic polymerizable vinyl monomer is suspension-polymerized, the hydrophilic polymerizable vinyl monomer does not participate in the polymerization reaction by transferring to the aqueous phase, so that the resin particles having strong hydrophilicity are produced. Is difficult to do.

For example, in Japanese Patent Laid-Open No. 4-96902, a polymerizable vinyl monomer is suspension-polymerized to a polymerization conversion rate of less than 90% (for example, 40 to 80%), and then a hydrophilic polymerizable vinyl monomer is added. A method of adding and polymerizing is disclosed. However, when a hydrophilic polymerizable vinyl monomer is added in the latter stage of suspension polymerization, resin particles of the hydrophilic polymerizable vinyl monomer alone are produced, or a large amount of powdery resin particles of 1 μm or less are produced. When obtaining the resin particles from the particle dispersion liquid, there is a problem that filtration efficiency and dewatering property are significantly reduced. In addition, since the resin particles aggregate during drying, it is necessary to sufficiently disintegrate, which complicates the production process. Furthermore, since the water-soluble resin obtained by polymerizing the hydrophilic polymerizable vinyl monomer alone dissolves in the water phase,
Even if a large amount of hydrophilic polymerizable vinyl monomer is used, it is difficult to produce highly hydrophilic resin particles.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and resin particles having strong hydrophilicity and excellent dispersibility in an aqueous medium, and such resin particles can be easily produced. It is an object of the present invention to provide a method and uses of resin particles obtained by the method.

[0006]

Means for Solving the Problems To achieve the above object, the present inventor has conducted extensive studies and as a result, uses a hydrophobic polymerizable vinyl monomer in which an azo polymerization initiator having a specific structure is dissolved. The hydrophilic polyoxyethylene structure can be introduced into the resin particles or on the surface thereof, and the obtained resin particles have strong hydrophilicity and are found to have excellent dispersibility in an aqueous medium. The invention was completed.

According to the invention, the general formula (I)

[Chemical 2] (In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, a lower alkyl group or a cyano group, and m is 1
Is an integer of 500, and n is an integer of 1 to 200).
There is provided a method for producing resin particles, which comprises subjecting a hydrophobic polymerizable vinyl monomer in which an azo-based polymerization initiator having a repeating unit is dissolved to an aqueous suspension polymerization in the presence of a zwitterionic surfactant. To be done.

Further, according to the present invention, resin particles having a polyoxyethylene structure obtained by the above method are provided. Further, according to the present invention, there is provided an external preparation and a coating material containing the above resin particles.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The resin particles of the present invention are obtained by subjecting a hydrophobic polymerizable vinyl monomer in which a specific azo polymerization initiator is dissolved to an aqueous suspension polymerization in the presence of a zwitterionic surfactant. To be

Examples of the hydrophobic polymerizable vinyl monomer (hereinafter referred to as "vinyl monomer") used in this method include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene,
2,4-dimethylstyrene, pn-butylstyrene,
p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, methoxystyrene, p-phenylstyrene, p -Styrene and its derivatives such as chlorostyrene and 3,4-dichlorostyrene, vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride, vinyl esters such as vinyl acetate, vinyl propionate and vinyl butyrate. , Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, Phenyl acrylate, α-chloroacrylic Α of methyl, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, etc. -Methylene aliphatic monocarboxylic acid esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone, N-vinyl pyrrole, N- Vinylcarbazole, N
-Vinyl indole and the like. These vinyl monomers can be used alone or in combination of two or more kinds.

In addition to the vinyl monomer, a hydrophilic monomer may be used in combination as long as the effect of the present invention is not impaired. Examples of the hydrophilic monomer include acrylic acid,
Methacrylic acid, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide,
Methacrylamide, 2-hydroxyethyl acrylate,
2-Hydroxypropyl acrylate, 2-methacrylic acid
Examples thereof include acrylic acid or methacrylic acid derivatives such as hydroxyethyl and 2-hydroxypropyl methacrylate, maleic acid, fumaric acid, N-vinyl compounds such as N-vinylpyrrolidone, and vinylnaphthalene salts.

The vinyl monomer includes the above-mentioned general formula (I).
The azo-based polymerization initiator represented by is dissolved. In the above general formula (I), examples of the lower alkyl group include methyl, ethyl, n-propyl, isopropyl and the like. The number average molecular weight of the azo polymerization initiator is 20
00-100,000 is preferable, and 5000-50000
Is more preferable. When the number average molecular weight of the azo polymerization initiator is less than 2000, it is difficult to obtain desired hydrophilicity and dispersibility in an aqueous medium, which is not preferable. Further, if the number average molecular weight of the azo-based polymerization initiator exceeds 100,000, the viscosity of the monomer phase becomes high, and it is difficult to obtain desired resin particles having a particle diameter of 1 μm or more, which is not preferable.

The azo-based polymerization initiator is usually used in an amount of about 0.1 to 10% by weight, preferably 0.2%, based on the vinyl monomer.
~ 5.0 wt% is used. When the amount of the azo-based polymerization initiator used is less than 0.1% by weight, it is difficult to obtain the desired effect of improving hydrophilicity, which is not preferable. On the other hand, if the amount of the azo polymerization initiator used exceeds 10% by weight, the effect of improving hydrophilicity commensurate with the amount used is not seen, and the solvent resistance and redispersibility in an aqueous medium decrease, which is not preferable.
The azo polymerization initiator may be once dissolved in a hydrophobic organic solvent such as toluene or ethyl acetate and then added to the vinyl monomer.

The above-mentioned azo-based polymerization initiator is, for example, a method of polycondensing azo group-containing dicarboxylic acid chloride and polyoxyethylene in the presence of a dehydrochlorinating agent, or a method of azo group-containing dicarboxylic acid and polyoxyethylene. It can be produced by a method such as polycondensation using a dehydration condensation reagent in the absence of a catalyst or a tertiary amine catalyst.

A polymerizable compound having two or more double bonds may be dissolved in the vinyl monomer as a crosslinking agent. Examples of such compounds include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and their derivatives, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol triacrylate, trimethylolpropane triacrylate, and other diethylenic carboxylic acids. Examples thereof include divinyl compounds such as esters, N, N-divinylaniline, divinyl ether, and divinylsulfite, and compounds having 3 or more vinyl groups. These compounds may be used alone or in combination of two or more.

Additives such as pigments may be added or dissolved in the vinyl monomer. Examples of such additives include titanium oxide, zinc oxide, zirconium oxide, magnesium oxide, iron oxide, iron hydroxide, chromium oxide, chromium hydroxide, ultramarine blue, dark blue, manganese violet, ultramarine violet, titanium black, carbon. Black, aluminum powder, titanium mica, bismuth oxychloride, iron oxide treated mica titanium, dark blue treated mica titanium, carmine treated mica titanium, silica, calcium carbonate, magnesium carbonate, barium sulfate, barium silicate, calcium silicate, magnesium silicate , Inorganic phosphates such as calcium phosphate, hydroxyapatite, zeolite, alumina, talc, mica, bentonite, kaolin, sericite, aluminum lakes such as tartrazine, sunsetero FCF, brilliant blue FCF, zirconium lake, Riumureki, Lyndon pink CN, Lithol Rubine BCA, Lake Red CBA, phthalocyanine blue, organic pigments such as permanent orange, and the like to.

In the vinyl monomer, in addition to the azo-based polymerization initiator represented by the general formula (I), an oil-soluble peroxide which is usually used in suspension polymerization as a polymerization initiator is used as long as the effect of the present invention is not impaired. A system polymerization initiator or an azo polymerization initiator other than the general formula (I) may be used in combination and dissolved.

Examples of the peroxide type polymerization initiator include benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, benzoyl orthochloroperoxide, benzoyl orthomethoxyperoxide, methyl ethyl ketone peroxide,
Diisopropyl peroxydicarbonate, cumene hydroperoxide, cyclohexanone peroxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide and the like can be mentioned.

Examples of azo-based polymerization initiators other than the general formula (I) include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), 2 , 2'-azobis (2,3-dimethylbutyronitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,3,3-trimethylbutyronitrile), 2,2'-azobis (2-isopropylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2- (carbamoylazo) isobutyronitrile,
4,4'-azobis (4-cyanovaleric acid), dimethyl-2,2'-azobisisobutyrate and the like can be mentioned. Among them, benzoyl peroxide, lauroyl peroxide,
2,2'-azobisisobutyronitrile and 2,2'-azobis (2,4-dimethylvaleronitrile) are preferred.

Examples of the zwitterionic surfactant used in the method of the present invention include lauryl dimethyl carboxy betaine, lauryl amido propyl betaine, lauryl amino acetic acid betaine, fatty acid amido propyl dimethyl amino acetic acid betaine, and lauryl carboxymethyl hydroxyethyl imidazolinium. Examples thereof include betaine and lauryl carboxymethyl hydroxypropyl sulfoammonium betaine.

The zwitterionic surfactant is used by appropriately adjusting the type and amount of the zwitterionic surfactant in consideration of the particle size of the obtained resin particles and the dispersion stability during polymerization. The amount of zwitterionic surfactant used is preferably 0.001 to 0.2% by weight, and 0.005 to 0.2% by weight, based on the water used in the aqueous suspension polymerization.
0.15% by weight is more preferable. When the amount of the zwitterionic surfactant used is less than 0.001% by weight, it becomes difficult to stably carry out suspension polymerization, which is not preferable. If the amount used exceeds 0.15% by weight, the effect corresponding to the amount used cannot be obtained, which is not preferable.

In the method of the present invention, if a surfactant such as an anionic surfactant, a cationic surfactant or a nonionic surfactant is used in addition to the zwitterionic surfactant, the resin is further stabilized. It is preferable because particles can be produced.

Examples of the anionic surfactant include fatty acid oils such as sodium oleate and potassium castor oil,
Alkyl sulfate ester salts such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, alkylnaphthalenesulfonates, alkanesulfonates,
Dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl phenyl ether sulfate ester salt,
Examples thereof include polyoxyethylene alkyl sulfate ester salts.

Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester. , Oxyethylene-
Examples thereof include oxypropylene block polymer.

In the method of the present invention, it is preferable to carry out the aqueous suspension polymerization in the presence of a suspension stabilizer in addition to the zwitterionic surfactant. Examples of the suspension stabilizer include calcium phosphate such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, phosphate such as zinc phosphate, calcium pyrophosphate, magnesium pyrophosphate, pyrophosphate such as aluminum pyrophosphate and zinc pyrophosphate. Acid salt,
Examples include sparingly water-soluble inorganic compounds such as calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate and colloidal silica. Of these, preferred are those which dissolve in water by reacting with acids or alkalis, such as tricalcium phosphate, magnesium pyrophosphate, calcium pyrophosphate and colloidal silica produced by the metathesis generation method.

The suspension stabilizer is used by appropriately adjusting the type and amount of the suspension stabilizer in consideration of the particle size of the obtained resin particles and the dispersion stability during polymerization. The amount of the suspension stabilizer used is preferably about 0.5 to 50% by weight, more preferably about 0.6 to 30% by weight, based on the vinyl monomer. If the suspension stabilizer content is less than 0.5% by weight, the dispersion stability will decrease,
It becomes difficult to obtain the target particle size, and if it exceeds 50% by weight, the effect corresponding to the amount used cannot be obtained, which is not preferable.

In the method of the present invention, a water-soluble polymerization inhibitor is used for the purpose of suppressing the secondary formation of fine particles of 1 μm or less due to emulsion polymerization in the aqueous phase within the range that does not impair the effects of the present invention. And it is preferable to carry out the aqueous suspension polymerization in the presence of a water-soluble electrolyte. Examples of the water-soluble polymerization inhibitor include electrolytes such as sodium chloride, magnesium chloride and calcium chloride, sodium nitrite and hydroquinone.

In the method of the present invention, a zwitterionic interface is used as a dispersion medium for 100 parts by weight of a vinyl monomer (hereinafter referred to as "monomer composition") in which the above-mentioned azo polymerization initiator and, if desired, other components are dissolved. Water containing an activator and other components (hereinafter referred to as "water phase") is 10
About 0 to 1000 parts by weight is used. The monomer composition and the aqueous phase may be mixed by adding the monomer composition to the aqueous phase or adding the aqueous phase to the monomer composition. In addition, the both may be added all at once or in small portions.

The aqueous suspension polymerization of the monomer composition is carried out by first
The monomer composition is finely dispersed in the aqueous phase to form monomer droplets. As a method for finely dispersing the monomer composition in the aqueous phase, for example, a method using a stirring force of a propeller blade or the like, a general homomixer which is a disperser using a high shear force composed of a rotor and a stator, or ultrasonic dispersion is used. Machine, a method using a high-pressure disperser that utilizes the collision force against the machine wall, such as a microfluidizer that uses the collision force between droplets, a nanomizer, or a monomer that passes through an MPG (microporous glass) porous film. And a method of press-fitting into the aqueous phase. By these dispersion methods, it is preferable that the monomer droplets in the monomer composition have a center diameter of about 1 to 100 μm.

Next, the polymerization is started by heating the dispersion liquid of the monomer composition and the aqueous phase. The stirring conditions during the polymerization may be such that the floating of the monomer droplets and the precipitation of the resin particles after the polymerization can be prevented. The polymerization temperature is preferably 50 to 90 ° C, and more preferably 60 to 80 ° C until the polymerization conversion rate reaches about 90% or more. Polymerization temperature is 5
When the temperature is lower than 0 ° C, the polymerization is difficult to proceed and the polymerization time becomes long, which is not preferable. Further, if the polymerization temperature exceeds 90 ° C., it becomes difficult to carry out the polymerization stably, which is not preferable. The time of the polymerization reaction is not particularly limited, but usually 0.5 to 15 hours is preferable. Further, when the polymerization conversion rate reaches about 90% or more, the polymerization temperature is adjusted to 95-12.
The polymerization reaction is completed at about 0 ° C. for about 0.1 to 5 hours.

After completion of the polymerization reaction, the reaction mixture is cooled and
The suspension stabilizer is dissolved in hydrochloric acid or the like, and the polymerized product is separated from the aqueous phase by operations such as suction filtration, centrifugation, centrifugal filtration, etc., washed with water, and dried to obtain resin particles. The particle size of the resin particles can be adjusted by adjusting the mixing ratio of the monomer composition and the aqueous phase, the addition amount of the suspension stabilizer and the like, stirring conditions, dispersion conditions and the like. The particle size of the resin particles is appropriately selected according to the application, but according to the production method of the present invention, it is usually possible to easily obtain resin particles having a particle size of about 1 to 100 μm.

Polymerization is initiated from the azo group by carrying out suspension polymerization using an azo polymerization initiator having a repeating unit of CH ₂ CH ₂ O as the polyoxyethylene structural unit represented by the general formula (I). The polyoxyethylene structural unit is introduced into the polymer chain as a polymerization initiator segment. The resin particles thus obtained have a hydrophilic polyoxyethylene structure in the particles or on the surface of the particles, have high hydrophilicity, and are excellent in dispersibility in an aqueous medium.

By incorporating the resin particles obtained by the method of the present invention into the external preparation, an external preparation having strong hydrophilicity and excellent dispersibility in an aqueous medium can be obtained. Such an external preparation is smooth and does not have a sticky feeling, and is particularly excellent in redispersibility in an aqueous liquid external preparation. The content of the resin particles in the external preparation is preferably 0.1 to 50% by weight,
0.2 to 30% by weight is more preferable. If the content of the resin particles with respect to the external preparation is less than 0.1% by weight, a clear effect due to the inclusion of the resin particles cannot be recognized, which is not preferable. When the content of resin particles exceeds 50% by weight,
Since no remarkable effect commensurate with the increase in the content is not recognized, it is not preferable in terms of production cost.

Examples of the external preparation containing the resin particles of the present invention include cosmetics and external medicines. The cosmetics are not particularly limited as long as the effects of the present invention are exhibited, and for example, pre-shave lotion, body lotion, lotion, cream, milky lotion, body shampoo, antiperspirant or other liquid-based one, soap, Cleaning cosmetics such as scrub cleansers, packs, shaving cream, towels, foundations, lipsticks, lip balms, blushers,
Eyebrow cosmetics, manicure cosmetics, hair wash cosmetics, hair dyes, hair styling products, aromatic cosmetics, toothpaste, bath agents, sunscreen products, suntan products, body powders, baby powders and other body products.

The external medicine is not particularly limited as long as it can be applied to the skin, and examples thereof include pharmaceutical creams, ointments, pharmaceutical emulsions, pharmaceutical lotions and the like. In addition, generally used additives can be added to these external preparations according to the purpose within a range that does not impair the effects of the present invention. Examples of such additives include water, lower alcohols, fats and waxes, hydrocarbons, higher fatty acids, higher alcohols, sterols, fatty acid esters, metal soaps, humectants, surfactants, polymer compounds, coloring material raw materials. , Fragrances, antiseptic / bactericidal agents, antioxidants, ultraviolet absorbers, other resin particles such as silicon particles and polystyrene particles, and special compounding additives.

By incorporating the resin particles obtained by the method of the present invention into a coating composition, a coating composition having excellent dispersibility can be obtained. This paint is suitable as an aqueous paint because it has excellent dispersibility of the resin particles in the water-based medium and can be dispersed in the water-based medium without using a special dispersing step and device. Further, according to this paint, a coating film excellent in touch and feel can be obtained.

The content of resin particles in the coating material is preferably 0.1 to 100 parts by weight, more preferably 0.2 to 80 parts by weight, based on 100 parts by weight of the resin binder for coating material. Other components that are generally used can be added to the coating material depending on the purpose, within a range that does not impair the effects of the present invention. Examples of such components include surfactants, polymer compounds, dyes, pigments, antioxidants, ultraviolet absorbers, special compounding components and the like.

[0039]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples. The hydrophilicity of the resin particles obtained in the following examples and comparative examples was evaluated by the following method.

That is, as shown in FIG.
Is sandwiched between a horizontal and smooth metal plate 1 and a resin film 3 and pressed at a pressure of 200 kg / cm ² to form a smooth resin particle layer. 1 cm high on the surface of this resin particle layer
The degree of hydrophilicity of the resin particles was measured by dropping one water droplet from a 25 ml buret and measuring the time until the water droplet was absorbed by the resin particle layer and disappeared (water droplet disappearing time). Those with a water drop disappearance time of less than 180 seconds were evaluated as having strong hydrophilicity, and those with a water drop disappearance time of 180 seconds or more were evaluated as having weak hydrophilicity.

[Production and Evaluation of Resin Particles] Example 1 Produced in 400 g of water by the metathesis method as a suspension stabilizer.
Zirconium ion interface with 10g of magnesium pyrophosphate
Lauryl dimethyl carboxy betaine as an activator.
08 g and lauryl sulphate as an anionic surfactant
0.08 g and sodium nitrite as a water-soluble polymerization inhibitor
Thorium (0.04 g) was dissolved to prepare an aqueous phase. Another
On the way, methylmethacryl as a hydrophobic polymerizable vinyl monomer
180g of relate, ethylene glycol dimethacrylate
Of the azo polymerization initiator of the general formula (I) (Wako
Junyaku Kogyo Co., Ltd., trade name: VPE-0201, general formula
R in (I) ¹And R³Is a methyl group, R²And R^Four
Is a cyano group and has a number average molecular weight of about 20,000.
To prepare a monomer composition.
It was

The monomer composition was added to the aqueous phase, and a homomixer (manufactured by IKA, trade name: ULTRA TURRAX) was added.
At T-25), the monomer droplets were finely dispersed by stirring for 5 minutes until the center diameter of the monomer droplets became about 10 μm. 1L of this suspension
The mixture was placed in an autoclave and sufficiently replaced with nitrogen, then, the stirring speed was kept at 200 rpm, and suspension polymerization was carried out at 60 ° C. for 10 hours. A part of the polymerized slurry after 10 hours was taken, and the polymerization conversion rate was calculated from the amount of unreacted monomer to be 98.2%. Then, the reaction temperature is increased from 60 ° C to 100 ° C by 2
The temperature was raised over 0 minutes and heated at 100 ° C. for 1 hour.

After completion of heating, the reaction mixture was cooled, and hydrochloric acid was added to the slurry after polymerization until the pH became about 2, to decompose the suspension stabilizer. Suction filtration was performed using a Buchner funnel equipped with filter paper, the suspension stabilizer was removed by washing the cake with 2.0 L of ion-exchanged water, and the dehydrated cake after suction filtration was dried to obtain resin particles. When the average particle size of the resin particles was measured with a Coulter Multisizer II type (manufactured by Coulter, Inc.), the average particle size was 9.5 μm. In addition, the resin particles have a strong hydrophilic property (water drop disappearance time 45
Sec), it was not aggregated.

Example 2 200 g of water, 200 g of a 10% calcium triphosphate dispersion slurry as a suspension stabilizer, 4 g of sodium chloride as an electrolyte, 0.08 g of lauryldimethylcarboxybetaine as a zwitterionic surfactant, and an anionic interface. An aqueous phase was prepared by dissolving 0.08 g of lauryl sulfate as an active agent. Separately, 190 g of methyl methacrylate as a hydrophobic polymerizable vinyl monomer, 10 g of ethylene glycol dimethacrylate, and general formula (I)
An azo-based polymerization initiator represented by (the same as in Example 1)
2.0 g was dissolved to prepare a monomer composition.

The monomer composition was added to the aqueous phase and finely dispersed in a homomixer (the same as in Example 1) for 5 minutes until the center diameter of the monomer droplets became about 25 μm. 1 of this suspension
After being placed in an L autoclave and sufficiently replaced with nitrogen, the stirring speed was maintained at 200 rpm, and suspension polymerization was carried out at 70 ° C. for 10 hours. A part of the polymerized slurry after 10 hours was taken, and the polymerization rate was calculated from the amount of unreacted monomer to be 97%. Then, the reaction temperature was raised from 70 ° C. to 100 ° C. over 20 minutes and heated at 100 ° C. for 1 hour.

After completion of heating, the reaction mixture was cooled, and hydrochloric acid was added to the slurry after polymerization until the pH reached about 2, to decompose the suspension stabilizer. Suction filtration was performed using a Buchner funnel equipped with filter paper, the suspension stabilizer was removed by washing the cake with 2.0 L of ion-exchanged water, and the dehydrated cake after suction filtration was dried to obtain resin particles. When the average particle size of the resin particles was measured with a Coulter Multisizer II type, the average particle size was 23.1 μm. In addition, the resin particles had strong hydrophilicity (water droplet disappearance time: 38 seconds) and were not aggregated.

Comparative Example 1 In 400 g of water, 10 g of magnesium pyrophosphate produced by the metathesis method as a suspension stabilizer, 0.16 g of lauryl sulfate as an anionic surfactant, and sodium nitrite as a water-soluble polymerization inhibitor 0 0.04 g was dissolved to prepare an aqueous phase.

Separately, 160 g of methyl methacrylate as a hydrophobic polymerizable vinyl monomer, 40 g of ethylene glycol dimethacrylate, and 2,2'-azobis (2,4) not included in the general formula (I) as an azo polymerization initiator.
-Dimethylvaleronitrile) (1.0 g) was dissolved to prepare a monomer composition. The monomer composition was added to the aqueous phase and stirred for 5 minutes with a homomixer (the same as in Example 1) until the center diameter of the monomer droplets became about 25 μm, and finely dispersed. This suspension was placed in a 1 L autoclave, and after sufficiently purging with nitrogen, the stirring speed was maintained at 200 rpm, and suspension polymerization was carried out at 55 ° C. for 10 hours. A part of the polymerization slurry after 10 hours was taken, and the polymerization rate was calculated from the amount of unreacted monomer, and it was 98.2%. Then, the reaction temperature is raised from 55 ° C to 100 ° C over 20 minutes,
Heated at 0 ° C. for 1 hour.

After completion of heating, the reaction mixture was cooled, and hydrochloric acid was added to the slurry after polymerization until the pH became about 2, to decompose the suspension stabilizer. Suction filtration was performed using a Buchner funnel equipped with filter paper, the suspension stabilizer was removed by washing the cake with 2.0 L of ion-exchanged water, and the dehydrated cake after suction filtration was dried to obtain resin particles. When the average particle diameter of the resin particles was measured with a Coulter Multisizer II type, the average particle diameter was 8.5 μm. Also, the resin particles,
The hydrophilicity was weak (water droplet disappearance time 920 seconds).

Further, Example 1, Example 2 and Comparative Example 1
The dispersibility of the resin particles obtained in 1 above in an aqueous medium was evaluated by the following method. That is, 0.1 g of resin particles was added to 50 ml of distilled water and stirred with a magnetic stirrer (MGP-301 type manufactured by Shibata Scientific Instruments Co., Ltd.) for 5 minutes. No resin particles were observed on the liquid surface, and those that were completely settled and dispersed in the liquid were marked with ◯, and resin particles were observed on the liquid surface were marked with ×.
The dispersibility of the resin particles in the aqueous medium was evaluated as. The results are shown in Table 1.

[0051]

[Table 1]

As is clear from Table 1, the resin particles of the present invention (Examples 1 and 2) are excellent in dispersibility in an aqueous medium.

Comparative Example 2 Resin particles were prepared in the same manner as in Example 1 except that the zwitterionic surfactant was not used. However, the entire system was gelated during the aqueous suspension polymerization reaction, and the resin particles were Couldn't get

Example 3 [Production and evaluation of body lotion] Resin particles obtained in Example 1 3 parts by weight Ethanol 50 parts by weight Glycyrrhizic acid 0.1 parts by weight Perfume 0.5 parts by weight Purified water 46.4 parts by weight The above components were thoroughly mixed with a mixer to obtain a body lotion.

Comparative Example 3 A body lotion was obtained in the same manner as in Example 3, except that the resin particles obtained in Comparative Example 1 were used instead of the resin particles obtained in Example 1. Example 3 and Comparative Example 3
The body lotion obtained in 1. was subjected to a sensory test by 5 panelists and a redispersibility test. As the evaluation items in this sensory test, elongation at the time of coating, uniform coating property, drop-off property of particles, and smoothness were selected, and the following criteria were used for evaluation. ○: 4 panelists evaluated that all evaluation items were good
More than people △ ・ ・ ・ 2 panelists who rated all evaluation items as good
~ 3 people × ... 1 panelist who evaluated all evaluation items as good
Less than people

The redispersibility test was evaluated by allowing the body lotion to stand at 40 ° C. for 30 days, then shaking by hand, and the number of times of shaking until all the precipitated resin particles were uniformly dispersed. ○ when dispersed less than 10 times,
When it exceeded 10 times, it was marked with x. The results of the above sensory test and redispersibility test are shown in Table 2.

[0057]

[Table 2] As is clear from Table 2, the external preparation of the present invention (body lotion of Example 3) is excellent in all of elongation at application, uniform application property, drop-off property of particles, and smoothness, and in liquid. It can be seen that the redispersion property of is excellent.

Example 4 [Manufacture and Evaluation of Paint] Resin Particles Obtained in Example 1 3 parts by weight Commercially available water-based resin binder liquid (solid content 30%) 20 parts by weight Each of the above components was used for 5 minutes with a paint shaker. Mix
Got the paint. This coating material was applied to coated paper with an applicator so that the coating thickness was 30 μm, and the coating was applied in an oven for 1 hour.
After drying for 2 hours, a coating film was obtained.

Comparative Example 4 A coating material and a coating film were obtained in the same manner as in Example 4 except that the resin particles obtained in Comparative Example 1 were used instead of the resin particles obtained in Example 1. The coating films of Example 4 and Comparative Example 4 were subjected to a sensory test by 5 panelists. As the evaluation items in this sensory test, texture and smoothness were selected, and evaluation was performed according to the following criteria. ○: 4 panelists evaluated that all evaluation items were good
More than people △ ・ ・ ・ 2 panelists who rated all evaluation items as good
~ 3 people × ... 1 panelist who evaluated all evaluation items as good
Table 3 shows the results of the sensory test for people and above.

[0060]

[Table 3]

As is clear from Table 3, the coating film (Example 4) using the coating material of the present invention is excellent in all of the texture and smoothness.

[0062]

According to the method of the present invention, the hydrophilicity is strong,
Resin particles having excellent dispersibility in an aqueous medium, having a particle diameter of 1 μm or more, and having no aggregation can be easily obtained. The external preparation containing the resin particles is smooth and has no sticky feeling,
Excellent redispersibility in liquid. Further, the coating material containing the above resin particles is excellent in texture and smoothness.

[Brief description of drawings]

FIG. 1 is a diagram showing a method for measuring a water drop disappearance time.

[Explanation of symbols]

1,4 metal plate 2 resin particles 3 resin film

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08F 283/06 C08F 283/06 4J043 C09D 5/02 C09D 5/02 153/00 153/00 201/00 201 / 00 // C08G 73/00 C08G 73/00 F-term (reference) 4C083 AC102 AD011 AD041 AD092 AD532 CC02 DD23 DD27 EE01 EE06 4J011 AA05 JA02 JA03 JA04 JA05 JA13 NA01 4J015 AA02 4J026 AB23 BA06 BA09 BA10 BA12 BA15 BA19 BA19 BA19 BA19 BA27 BA40 4J038 CC011 CC021 CC071 CD021 CD081 CD101 CE051 CF011 CF021 CG141 CH031 CH041 CH081 CH241 CK021 CQ001 DF042 KA03 KA08 LA02 NA06 4J043 PA04 PA05 PA09 QB64 RA15 UB261 XA12 XB19 XB26 ZB01 ZB26 ZB33

Claims (8)

[Claims] 1. A compound represented by the general formula (I): (In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, a lower alkyl group or a cyano group, and m is 1
Is an integer of 500, and n is an integer of 1 to 200).
A method for producing resin particles, which comprises subjecting a hydrophobic polymerizable vinyl monomer, in which an azo-based polymerization initiator having a repeating unit shown in 1) is dissolved, to aqueous suspension polymerization in the presence of a zwitterionic surfactant. 2. The number average molecular weight of the azo polymerization initiator is 20.
The manufacturing method according to claim 1, which is from 00 to 100,000. 3. The production method according to claim 1, wherein the aqueous suspension polymerization is carried out in the presence of a zwitterionic surfactant and a suspension stabilizer. 4. The method according to claim 3, wherein the suspension stabilizer is used in a proportion of 0.5 to 50% by weight based on the hydrophobic polymerizable vinyl monomer. 5. The method according to claim 3, wherein a poorly water-soluble inorganic compound is used as the suspension stabilizer. 6. Resin particles having a polyoxyethylene structure, which are obtained by the method according to claim 1. 7. An external preparation containing the resin particles according to claim 6. 8. A paint comprising the resin particles according to claim 6.