WO2016067904A1 - Resin particle dispersion and use thereof - Google Patents

Abstract

Provided are: a resin particle dispersion in which the resin particles, even after long-term storage, have redispersibility; a process for producing the resin particle dispersion; and a cosmetic preparation in which the resin particles, even after long-term storage, have redispersibility. The process for producing the resin particle dispersion comprises: step (I) in which a polymerizable ingredient comprising a polymerizable monomer is dispersed in an aqueous dispersion medium containing an inorganic ingredient and a low-molecular surfactant; step (II) in which the polymerizable ingredient is polymerized to obtain resin particles; powder formation step (IV) in which after the step (II), a powder of the resin particles is obtained from the aqueous dispersion medium containing the resin particles; and mixing step (V) in which after the step (IV), the resin particles are mixed with water, an alcohol, and an organic acid to obtain a resin particle dispersion, the organic acid being a specific organic acid.

Description

Resin particle dispersion and use thereof

The present invention relates to a resin particle dispersion and use thereof.

It is widely practiced to use particles in cosmetics to provide functions such as improved tactile feel and retention of active ingredients. However, for liquid cosmetics, the contained particles settle, so the particles often block after long-term storage, and it is necessary to re-disperse the particles before use, especially in liquid cosmetics containing alcohol. Because of the strong blocking, re-dispersion is difficult and the use of particles is limited due to the problem of quality stability. For this reason, improving the redispersibility by preventing particle blocking is a major technical problem in this field.

At present, the surface treatment of particles is mainly used to prevent particle blocking. For example, in Patent Document 1, the particles are subjected to surface treatment with a nonionic substance, and redispersibility is expressed by coexisting an inorganic salt or an organic salt. In Patent Document 2, redispersibility is expressed by hydrophobizing the particles and using a specific surfactant in combination.
However, the surface treatment of the particles is costly and sticky, and there are limitations when developing products.

Examples of using particles that are not subjected to surface treatment include Patent Document 3 and Patent Document 4. In Patent Document 3, it is said that the redispersibility is good by using particles having a true specific gravity of 1.3 or less. However, since the particles are light, the sedimentation is slowed down. The redispersibility after storage was insufficient. In Patent Document 4, redispersibility is achieved by blending 0.1 to 20% by weight of powder, 0.2 to 5.0% by weight of organic acid and / or salt thereof, and 55.0 to 99.7% by weight of alcohol. However, depending on the formulation of the product, there may be cases where a sufficient effect cannot be obtained, and because there is a need for a higher alcohol concentration, there are restrictions on product development such as being limited to cosmetics for men. is there.

Although there is a demand for blending particles into liquid cosmetics in this way, it cannot be said that the product has been fully developed due to limitations in use. For this reason, there is a demand for a formulation with high particle redispersibility and high degree of freedom in product design.

Japanese Unexamined Patent Publication No. 11-292738 Japanese Unexamined Patent Publication No. 2009-234994 Japanese Unexamined Patent Publication No. 6-271419 Japanese Unexamined Patent Publication No. 2001-354512

An object of the present invention is to provide a resin particle dispersion having redispersibility even after long-term storage, a method for producing the resin particle dispersion, and a cosmetic having redispersibility even after long-term storage.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a resin particle dispersion containing specific resin particles, water, alcohol and organic acid dispersion at a specific weight ratio. I found that the problem could be solved.
That is, the method for producing a resin particle dispersion of the present invention comprises the step (I) of dispersing a polymerizable component containing a polymerizable monomer in an aqueous dispersion medium containing an inorganic component and a low molecular surfactant. Step (II) for obtaining resin particles by polymerizing a functional component, pulverization step (IV) for obtaining resin particle powder from an aqueous dispersion medium containing resin particles after Step (II), and after Step (IV) A mixing step (V) in which the resin particles, water, alcohol and organic acid are mixed to obtain a resin particle dispersion, wherein the organic acid is a hydroxy acid, polyvalent carboxylic acid, aminocarboxylic acid, phenolsulfonic acid or hydroxy acid; Select from partially neutralized salts, partially neutralized polycarboxylic acids, partially neutralized aminocarboxylic acids, and partially neutralized phenolsulfonic acids. At least one kind of resin It is a manufacturing method of a child dispersion.

It is preferable to further include a step (III) of dissolving the inorganic component after the step (II).
The resin particles after step (IV) preferably have an average particle size of 0.1 to 100 μm and a bulk specific gravity of 0.8 or less.
The polymerizable monomer is a (meth) acrylic acid ester monomer, a carboxyl group-containing monomer, a styrene monomer, a nitrile monomer, a vinyl monomer, or an amide group-containing monomer. And at least one selected from maleimide monomers and vinylidene chloride.
The inorganic component is preferably at least one selected from colloidal silica, calcium phosphate, magnesium phosphate, magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium carbonate, calcium pyrophosphate and magnesium pyrophosphate.
The hydroxy acid is at least one selected from lactic acid, tartaric acid, citric acid and malic acid, and the polyvalent carboxylic acid is selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid and fumaric acid And the aminocarboxylic acid is ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, dihydroxyethylethylenediaminediacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid and triethylenetetraamine hexaacetic acid. It is at least one selected from acetic acid, and the phenolsulfonic acid is preferably at least one selected from phenolsulfonic acid and benzotriazolylbutylphenolsulfonic acid.

The resin particle dispersion of the present invention is a resin particle dispersion obtained by blending resin particles, water, alcohol and an organic acid, wherein the resin particles have an average particle diameter of 0.1 to 100 μm, and the resin particles The bulk specific gravity of the resin particles is 0.8% or less, the water-soluble substance content of the resin particles measured by the following measurement method is 0.2% by weight or less, and the organic acid is a hydroxy acid, polyvalent carboxylic acid, amino Carboxylic acid, phenolsulfonic acid, salt partially neutralized with hydroxy acid, salt partially neutralized with polycarboxylic acid, salt partially neutralized with aminocarboxylic acid and phenolsulfonic acid It is a resin particle dispersion which is at least one member selected from partially neutralized salts.
(Method for measuring content of water-soluble substance: 20 g of resin particles are precisely measured (A), added to 70 ml of ion-exchanged water and boiled for 5 minutes at 100 ° C. After cooling to 20 ° C., the volumetric flask and 20 ° C. (B) This dispersion is filtered through a membrane filter (made by Nitrocellulose, 0.02 μm mesh), and 40 ml of this filtrate is accurately collected using a whole pipette. Collect (C), transfer to a beaker that has been accurately weighed in advance (W ₀ ), evaporate to dryness in a water bath, and dry for 1 hour at 110 ° C. The residue from the evaporative dryness and the beaker do not absorb moisture Thus, after cooling to room temperature in the desiccator, when the weight of the beaker is precisely measured again (W ₁ ), the value calculated from the following formula (4) is taken as the water-soluble substance content.)
Water-soluble substance content = (W ₁ −W ₀ ) / {A × (C / B)} × 100 (% by weight) (4)

The resin particle dispersion of the present invention is a resin particle dispersion containing resin particles, water, alcohol and an organic acid, and the resin particles are polymerized in an aqueous dispersion medium containing an inorganic component and a low molecular surfactant. Resin particles obtained by dispersing a polymerizable component containing a polymerizable monomer and polymerizing the polymerizable component, wherein the organic acid is a hydroxy acid, a polyvalent carboxylic acid, an aminocarboxylic acid, or a part of the hydroxy acid. It is at least one selected from a neutralized salt, a salt in which a part of a polycarboxylic acid is neutralized, and a salt in which a part of an aminocarboxylic acid is neutralized.

The resin particle dispersion of the present invention preferably has a volume ratio defined by the following mathematical formula (1) of 5 or more.
Volume ratio = sedimentation layer volume / resin particle volume (1)
(In the formula (1), the sedimented bed volume means that 100 ml of the resin particle dispersion test solution is put into a 100 ml cylindrical graduated cylinder and left to stand at 25 ° C. for 3 months in a state covered with a parafilm. (The sediment volume formed from the settled particles is a value read from the scale of the graduated cylinder. The resin particle volume is a value calculated from the following mathematical formula (2).)
Resin particle volume = resin particle weight / true specific gravity of resin particle (2)
The cosmetic of the present invention contains the resin particle dispersion.

Since the resin particle dispersion obtained by the method for producing a resin particle dispersion of the present invention has redispersibility even after long-term storage, it can be applied to cosmetic applications. Since the resin particle dispersion of the present invention has redispersibility even after long-term storage, it can be applied to cosmetic applications. The cosmetic of the present invention is excellent in quality stability because the resin particles do not block even after long-term storage and have redispersibility.

The resin particle dispersion of the present invention contains water, alcohol and organic acid, and specific resin particles are dispersed. Hereinafter, each component will be described.

(Resin particles)
The resin particles are resin particles obtained by dispersing a polymerizable component containing a polymerizable monomer in an aqueous dispersion medium containing an inorganic component and a low molecular surfactant, and polymerizing the polymerizable component.
Usually, the polymerization performed by dispersing a polymerizable component in an aqueous dispersion medium (hereinafter sometimes referred to as suspension polymerization) is performed using a water-soluble polymer such as polyvinyl alcohol or methyl cellulose as a dispersant. However, resin particles produced using a water-soluble polymer as a dispersant have a part of the water-soluble polymer incorporated in the resin particle, so that the dispersant is completely removed even after washing. I can't. Alcohol permeates into the resin particles based on the remaining dispersant, and the resin particles swell so that the resin particles tend to aggregate to form a strong blocking.
When the dispersing agent contains an inorganic component and a low molecular surfactant, the dispersing agent is hardly taken into the resin particles, so that the resin particles hardly aggregate even in the presence of alcohol. When the dispersant is composed of an inorganic component and a low molecular surfactant, since the dispersant is not taken into the resin particles, the accuracy with which the resin particles hardly aggregate even in the presence of alcohol is increased.

Examples of the polymerizable monomer include (meth) acrylic acid ester monomer, carboxyl group-containing monomer, styrene monomer, nitrile monomer, vinyl monomer, amide group-containing monomer , Maleimide monomers, and vinylidene chloride are preferable from the viewpoint of easily obtaining the effect of the present application. Among these, when used in cosmetics, methyl methacrylate and styrene whose safety has been confirmed are more preferable. These monomers may be used alone or in combination of two or more. In addition, (meth) acryl shall mean methacryl or acrylic.

In the suspension polymerization, a polymerizable component that essentially contains a polymerizable monomer is suspended in an aqueous medium that essentially contains a dispersant and then polymerized. In addition to the polymerizable monomer, the polymerizable component may contain a polymerization initiator, a crosslinking agent, a pore-forming agent, and an encapsulating agent.
The polymerization initiator is not particularly limited, and a known polymerization initiator can be used. For example, organic peroxides such as dilauroyl peroxide and benzoyl peroxide; azo series such as 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile) A polymerization initiator can be mentioned.

A cross-linking agent is a radical polymerizable monomer having two or more polymerizable double bonds. By polymerizing using a cross-linking agent, the solvent resistance of the resin particles is improved and the shape can be easily maintained even in high alcohol. Become. Although it does not specifically limit as a crosslinking agent, For example, aromatic divinyl compounds, such as divinylbenzene; Allyl methacrylate, triacryl formal, triallyl isocyanate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1 , 4-butanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, PEG # 200 di (meth) acrylate, PEG # 600 di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Di (meth) acrylate compounds such as pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, etc. Give Door can be.

The weight ratio of the crosslinking agent is preferably 0 to 40% by weight, more preferably 0.05 to 30% by weight, still more preferably 0.1 to 25% by weight, particularly preferably 0.5%, based on the polymerizable component. ~ 20% by weight. If the weight ratio of the cross-linking agent exceeds 40% by weight, a large amount of unreacted polymerizable monomer remains, which may impair the safety of the cosmetic.

The pore-forming agent is an organic solvent for making the resin particles into a hollow body, and there is no particular limitation as long as the polymerizable monomer before the reaction dissolves but the polymer after the polymerization does not dissolve. For example, butane, pentane, hexane, heptane and the like can be mentioned.
The weight ratio of the pore former is preferably 30% by weight or less, more preferably 25% by weight or less, based on the polymerizable component. If the weight ratio of the pore former exceeds 30% by weight, the physical strength of the resin particles may be lowered. A preferred lower limit is 0% by weight.

The resin particles may be an encapsulated capsule type. Examples of the encapsulating agent include cosmetic oils such as squalane, liquid paraffin, silicone oil and ester oil. Encapsulating cosmetic oil not only adds moisture retention and other effects to the resin particles, but also makes it possible to make the resin particles atypical, and the atypical particles have a lower bulk specific gravity and improve redispersibility. Therefore, it is preferable.

The average particle diameter of the resin particles is not particularly limited because it can be designed freely according to the use, but is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm, and particularly preferably 1.0 to 30 μm. If the thickness is less than 0.1 μm, the yield of the product may be significantly reduced, which may be disadvantageous in terms of cost. If the thickness is more than 100 μm, the product may have a rough feeling and the usability may be deteriorated.

The bulk specific gravity of the resin particles is a specific gravity calculated by filling the resin particles in a container whose volume is known, and dividing the weight of the resin particles by the volume of the container. The bulk specific gravity is the volume of the particles between the resin particles. It includes the volume of the gap and the volume of the gap between the resin particles and the container. A high bulk specific gravity indicates that the particles are densely packed, and a low bulk specific gravity indicates that the space other than the particles is wide.
In the resin particle dispersion, the lighter the bulk specific gravity, the fewer the contact points of the resin particles, the fewer the aggregation points, and the larger the space other than the resin particles in the sedimentation layer, the easier the liquid components flow when subjected to vibration. Therefore, the redispersibility is improved.

The bulk specific gravity of the resin particles is not particularly limited because it can be freely designed according to the use, but is preferably 0.8 or less, more preferably 0.77 or less, and even more preferably 0.75 or less, particularly preferably. Is 0.7 or less, most preferably 0.65 or less. When the bulk specific gravity exceeds 0.8, there are many contact points between the resin particles, and the particles tend to aggregate during long-term storage, which may reduce redispersibility.
A preferred lower limit is 0.1. When the bulk specific gravity is 0.1 or less, since the resin particles are too light, miscibility may be impaired in the resin particle dispersion.

The water-soluble substance content of the resin particles is not particularly limited because it can be designed freely according to the use, but is preferably 0.2% by weight or less, more preferably 0.15% by weight or less, and still more preferably 0. .12% by weight or less, most preferably 0.10% by weight or less. When the water-soluble substance content exceeds 0.2% by weight, the resin particles are likely to swell, agglomerate, block, and the like due to alcohol, and the redispersibility may be lowered.
A preferred lower limit of the water-soluble substance content of the resin particles is 0% by weight. The said resin particle here means the resin particle in the powder state after drying. A method for measuring the water-soluble substance content will be described later.

Examples of the shape of the resin particles include a spherical shape, a bowl shape, a bowl-elliptical shape, a surface irregularity shape, and a fine particle adhesion shape, and a plurality of resin particles can be combined. The shape can be freely designed by adjusting the conditions during suspension polymerization by a known method. Moreover, if it is less than 50 weight% among resin particles, the particle | grains comprised from nylon, urethane, silicone, a cellulose, etc. may be included.
The shape of the resin particles can be freely selected from performances other than the redispersibility required for the resin particle dispersion. However, when the shape is spherical, it is preferable because a smooth feeling can be easily obtained when blended into a cosmetic.

The inorganic component is at least one selected from colloidal silica, calcium phosphate, magnesium phosphate, magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium carbonate, calcium pyrophosphate, and magnesium pyrophosphate, after completion of the suspension polymerization. This is preferable because it can be easily removed by adjusting the pH.
The weight ratio of the inorganic component is not particularly limited because it can be freely designed according to the use, but is preferably 1.0 to 80% by weight, more preferably 2.0 to 60% with respect to the polymerizable component. % By weight, more preferably 2.5 to 50% by weight, particularly preferably 3.0 to 40% by weight. When the weight ratio of the inorganic component is less than 1% by weight, the stability of the suspension is lowered, and the yield of the resin particles may be significantly lowered. When the weight ratio of the inorganic component exceeds 80% by weight, the viscosity of the suspension increases, which may make it difficult to control during polymerization.
The inorganic component can be dissolved after polymerization of the resin particles depending on the performance other than the redispersibility required for the resin particle dispersion. When the inorganic component is colloidal silica, the pH of the aqueous medium containing the resin particles obtained in the step (II) described later is adjusted to 10.5 or higher, and further heated to 50 ° C. or higher to colloidal silica. Dissolves well.
When the inorganic component is calcium phosphate, magnesium phosphate, magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium carbonate, calcium pyrophosphate and magnesium pyrophosphate, an aqueous solution containing the resin particles obtained in step (II) described later The inorganic component is ionically decomposed by adjusting the pH of the medium to less than 7.0.

The low molecular surfactant is a surfactant having a molecular weight of less than 1000. Examples of the low molecular surfactant include a low molecular cationic surfactant, a low molecular anionic surfactant, a low molecular nonionic surfactant, and a low molecular amphoteric surfactant.
The low molecular surfactant is not particularly limited, and examples thereof include low molecular cationic surfactants such as N-hydroxyethylpropylalkylamide nitrate, lauryltrimethylammonium choloride, lauryldimethylbenzylammonium chloride; fatty acid salts, Low molecular weight anionic surfactants such as sulfate ester lauryl sulfate, polyoxyethylene secondary alkyl ether sulfate ester, sulfonate alkylbenzene sulfonate, dioctyl sulfosuccinate, phosphate ester salts; polyoxyethylene Alkyl ethers, polyoxyethylene styrenated phenol ethers, polyoxyethylene alkylamino ethers, polyethylene glycol fatty acid esters, polyoxyethylene polyoxy Propylene glycols, glycerin fatty acid esters, polyoxyethylene castor oils, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkanolamides, polyoxyethylene fatty acid alkanolamides, adipic acid-diethanolamine condensates, etc. Low molecular nonionic surfactants; low molecular amphoteric surfactants such as alkyl betaines, amidopropyl betaines, and alkylene oxide adduct betaines.

The weight ratio of the low-molecular-weight surfactant is not particularly limited because it can be freely designed according to the use, but is preferably 10% by weight or less, more preferably 8.0% by weight or less, based on the polymerizable component. Particularly preferred is 5.0% by weight or less, and most preferred is 3.0% by weight or less. When the weight ratio of the low molecular surfactant exceeds 10% by weight, a large amount of fine particles are generated, and the yield of the resin particles may be significantly reduced. A preferred lower limit is 0% by weight.

(Organic acid)
The organic acid is an essential component for the resin particle dispersion of the present invention, and plays a role in preventing the alcohol from being immersed in the resin particle by adsorbing the organic acid to the resin particle.
The organic acid is not particularly limited for the above reasons, but is a hydroxy acid, a polyvalent carboxylic acid, an aminocarboxylic acid, a phenolsulfonic acid, a salt obtained by neutralizing a part of the hydroxy acid, or a polyvalent carboxylic acid. When at least one selected from a partially neutralized salt, a partially neutralized aminocarboxylic acid salt, and a partially neutralized phenolsulfonic acid salt is adsorbed to the resin particles. It is preferable because it is easy.
On the other hand, when all the carboxyl groups of the organic acid are neutralized, the adsorptivity to the resin particles is reduced, so that the immersion of alcohol into the resin particles cannot be prevented, and the resin particles are strongly agglomerated. This is not preferable because

The hydroxy acid is preferably lactic acid, tartaric acid, citric acid, or malic acid.
The polyvalent carboxylic acid is preferably oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, or fumaric acid.
The aminocarboxylic acid is preferably ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, dihydroxyethylethylenediaminediacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid and triethylenetetraaminehexaacetic acid.
The salt in which a part of the hydroxy acid is neutralized is preferably a salt in which a part of lactic acid, tartaric acid, citric acid or malic acid is neutralized. The salt is not particularly limited as long as it is a salt in which a part of the hydroxy acid is neutralized, so that the effect of the present invention is exhibited for the above reasons, but as a neutralizing agent for a salt in which a part of the hydroxy acid is neutralized, L-arginine It is preferable to use one or more basic compounds selected from potassium hydroxide, sodium hydroxide, ammonia, 2-aminomethyl-1-propanol, 2-aminomethyl-propanediol and tris (hydroxymethyl) aminomethane. Specific examples include 1 sodium citrate, 2 sodium citrate, 1 sodium lactic acid, 1 sodium malate, 1 potassium citrate, 2 potassium citrate, 1 potassium lactic acid, and 1 potassium malate.
The degree of neutralization of the salt in which a part of the hydroxy acid is neutralized is preferably 0.1 to 0.9 equivalent, more preferably 0.2 to 0.8 equivalent in terms of the number of neutralizing agent equivalents per equivalent of hydroxy acid. Preferably, 0.3 to 0.7 equivalent is more preferable, and 0.4 to 0.6 equivalent is particularly preferable.
When used in cosmetics, at least one selected from monosodium citrate, disodium citrate, monopotassium citrate and dipotassium citrate is preferable from the viewpoint of safety and cost.

The salt in which a part of the polyvalent carboxylic acid is neutralized is preferably a salt in which a part of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid or fumaric acid is neutralized.
If it is a salt in which a part of the polyvalent carboxylic acid is neutralized, the effect of the present application is exhibited for the above reasons, but there is no particular limitation. One or more basic compounds selected from L-arginine, potassium hydroxide, sodium hydroxide, ammonia, 2-aminomethyl-1-propanol, 2-aminomethyl-propanediol and tris (hydroxymethyl) aminomethane It is preferable. Specific examples include monosodium succinate, monopotassium succinate, monosodium glutarate, and monopotassium glutarate.
The degree of neutralization of the salt in which a part of the polyvalent carboxylic acid is neutralized is preferably 0.1 to 0.9 equivalent in terms of the number of neutralizing agent equivalents relative to 1 equivalent of the polyvalent carboxylic acid, and preferably 0.2 to 0. 8 equivalents are more preferred, 0.3 to 0.7 equivalents are more preferred, and 0.4 to 0.6 equivalents are particularly preferred.
When used for cosmetics, monosodium glutarate and monopotassium glutarate are preferable from the viewpoint of safety and cost.

Salts partially neutralized with aminocarboxylic acid are ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, dihydroxyethylethylenediaminediacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid or triethylenetetraacetic acid. A salt in which a part of amine hexaacetic acid is neutralized is preferred.
If the salt is a partially neutralized salt of aminocarboxylic acid, the effect of the present invention is exhibited for the above reasons, and is not particularly limited. However, as a neutralizing agent for a salt partially neutralized with aminocarboxylic acid, L Use of one or more basic compounds selected from arginine, potassium hydroxide, sodium hydroxide, ammonia, 2-aminomethyl-1-propanol, 2-aminomethyl-propanediol and tris (hydroxymethyl) aminomethane preferable. Specific examples include 2 sodium dihydrogenethylenediaminetetraacetate or 2 potassium dihydrogenethylenediaminetetraacetate.
The degree of neutralization of the salt in which a part of the aminocarboxylic acid is neutralized is preferably 0.1 to 0.9 equivalent, preferably 0.2 to 0.8 equivalent in terms of the number of neutralizing agent equivalents per equivalent of aminocarboxylic acid. Is more preferable, 0.3 to 0.7 equivalent is more preferable, and 0.4 to 0.6 equivalent is particularly preferable.
When used in cosmetics, disodium ethylenediaminetetraacetic acid disodium is preferable from the viewpoint of safety and cost.
The salt in which a part of phenolsulfonic acid is neutralized is preferably a salt in which part of phenolsulfonic acid or benzotriazolylbutylphenolsulfonic acid is neutralized.
If the salt is obtained by neutralizing a part of phenolsulfonic acid, the effect of the present invention is exhibited for the above reasons, but the salt is not particularly limited, but sodium salt or zinc salt is preferable. Specific examples include sodium phenol sulfonate, zinc phenol sulfonate, and sodium benzotriazolyl butyl phenol sulfonate.
As the degree of neutralization of the salt in which a part of the phenolsulfonic acid is neutralized, it is preferable that only the sulfonic acid part is neutralized and the phenol part is not neutralized.
When used in cosmetics, sodium phenolsulfonate or zinc phenolsulfonate is preferred from the standpoints of safety and cost.

(water)
Examples of water include tap water, ion-exchanged water, purified water, hard water, soft water, natural water, deep ocean water, electrolytic alkali ion water, electrolytic acid ion water, ion water, and cluster water. When used, these waters may be further sterilized by electron beam irradiation, UV irradiation, heat treatment, chlorination or the like. From the viewpoint of cost, tap water, ion exchange water or soft water is preferable.

(alcohol)
Alcohol is an essential component for the resin particle dispersion of the present invention, and has a role of accelerating the volatilization of the liquid component and giving a refreshing feeling.
Examples of the alcohol include ethanol and isopropyl alcohol. From the viewpoint of safety when used as a cosmetic, ethanol is preferable.

[Resin particle dispersion]
The weight ratio of the resin particles in the resin particle dispersion is preferably 1.0 to 10.0% by weight, more preferably 1.0 to 9.0% by weight, and further 1.0 to 8.0% by weight. 1.0 to 7.0% by weight is particularly preferable, and 1.0 to 6.0% by weight is most preferable. If it is less than 1.0% by weight, the resin particles may be insufficient and a smooth feeling may not be obtained. If it exceeds 10% by weight, there may be a powdery feeling with many resin particles.

The weight proportion of the alcohol in the resin particle dispersion is preferably 5.0 to 80% by weight, more preferably 6.0 to 70% by weight, even more preferably 7.0 to 60% by weight, and 8.0 to 50% by weight is particularly preferred, and 10 to 40% by weight is most preferred. If it is less than 5.0% by weight, the refreshing feeling may be insufficient. If it exceeds 80% by weight, the irritation by alcohol may be too strong.

The weight ratio of the organic acid in the resin particle dispersion is preferably 0.001 to 5.0% by weight, more preferably 0.002 to 4.8% by weight, and still more preferably 0.003 to 4.5%. % By weight, most preferably 0.005 to 4.0% by weight. When the weight ratio of the organic acid in the resin particle dispersion is less than 0.001% by weight, the organic acid adsorbed on the resin particles is small and the resin particles may be aggregated. When the weight ratio of the organic acid in the resin particle dispersion exceeds 5.0% by weight, it is difficult to adjust the pH of the resin particle dispersion.

[Method for producing resin particle dispersion]
The method for producing a resin particle dispersion of the present invention comprises a step (I) of dispersing a polymerizable component in an aqueous dispersion medium containing an inorganic component and a low molecular surfactant, and polymerizing the polymerizable component to obtain resin particles. It includes a obtaining step (II), a powdering step (IV) and a mixing step (V).

(Step of dispersing polymerizable component (I))
The step of dispersing the polymerizable component is a step of obtaining a suspension by dispersing an oily solution essentially containing the polymerizable component in an aqueous dispersion medium containing an inorganic component and a low molecular surfactant. From the viewpoint of easily obtaining the effect of the present application, the step of dispersing in an aqueous dispersion medium comprising an inorganic component and a low molecular surfactant to obtain a suspension is preferable.
Examples of the method for suspending and dispersing the polymerizable component include, for example, a method of stirring with a homomixer (for example, manufactured by Primics), a homodisper (for example, manufactured by Primics), cleamics (manufactured by Mtechnics), or a static mixer. For example, a general dispersion method such as a method using a static dispersion device such as Noritake Engineering Co., Ltd., a membrane emulsification method, an ultrasonic dispersion method, a microchannel method, or the like can be given.

(Step of obtaining resin particles by polymerizing polymerizable components (II))
The step (II) for obtaining resin particles by polymerizing a polymerizable component is a step for obtaining resin particles by heating the suspension obtained in the step (I).
The polymerization temperature is freely set depending on the kind of the polymerization initiator, but is preferably controlled in the range of 40 to 100 ° C., more preferably 45 to 90 ° C., and particularly preferably 50 to 85 ° C. The initial polymerization pressure is 0 to 5.0 MPa, more preferably 0.1 to 3.0 MPa, and particularly preferably 0.2 to 2.0 MPa in terms of gauge pressure.
During the polymerization reaction, it is preferable to stir the dispersion, and the stirring may be performed so gently as to prevent, for example, floating of the polymerizable component and sedimentation of the resin particles after polymerization.

(Inorganic component dissolution step (III))
According to the method for producing the resin particle dispersion of the present invention, according to the performance other than the redispersibility required for the resin particle dispersion, the inorganic material is added after the completion of the step (II) and before the powdering step (IV) which is the next step. An inorganic component dissolving step (III) in which the component is dissolved to reduce the residual amount of the inorganic component can be included.
When performing the dissolution step, the operation method varies depending on the type of dispersant used.
When the inorganic component is colloidal silica, the pH of the aqueous medium containing the resin particles obtained in the step (II) is adjusted to 10.5 or higher, heated to 50 ° C. or higher, and then the powder in the next step By carrying out the soaking step (IV), the remaining amount of the inorganic component can be reduced.
When the inorganic component is calcium phosphate, magnesium phosphate, magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium carbonate, calcium pyrophosphate and magnesium pyrophosphate, the aqueous medium containing the resin particles obtained in step (II) The residual amount of the inorganic component can be reduced by adjusting the pH to 7.0 or less and carrying out the powdering step (IV) as the next step after the inorganic component dissolving step (III).

(Powdering process (IV))
The method for producing a resin particle dispersion of the present invention includes a pulverization step (IV) for obtaining a powder of resin particles from an aqueous dispersion medium containing resin particles after the step (II).
The pulverization step (IV) includes a dehydration step (IV-1) and / or a drying step (IV-2).
The dehydration step (IV-1) can be performed by a general dehydration method such as suction filtration, pressure filtration, centrifugal dehydration, and centrifugal separation. In the dehydration step (IV-1), a wet powder of resin particles can be obtained by filtration or the like. The wet powder is a powder composed of water and resin particles having a moisture content of preferably 5.0 to 60% by weight, more preferably 15 to 50% by weight, and most preferably 20 to 40% by weight. Moreover, it is also possible to refine | purify a resin particle by adding water again to the obtained wet powder, and repeating dispersion | distribution and dehydration.
In particular, when a centrifugal dehydrator or a filter press dehydrator is used, the resin particles can be easily washed and purified by adding water to the filtration chamber.
The drying step (IV-2) can be performed by a general powder drying method. For example, a shelf dryer (box-type dryer), a vacuum dryer, a freeze dryer, a flash dryer, a spray dryer, and the like. The method of drying with is mentioned. A dehydration step (IV-1) may be included before the drying step (IV-2).
The term “drying” as used herein means that the amount of water in the resin particles is less than 5.0% by weight, preferably 2.0% by weight or less, more preferably 1.5% by weight or less.
Although it is possible to perform the step (V) using the resin particles obtained in the step (IV-1), there is a risk that bacteria will grow if moisture remains when used in cosmetics. Therefore, it is preferable to perform the step (IV-2).

(Mixing step (V))
The method for producing a resin particle dispersion of the present invention includes a mixing step (V) in which resin particles, water, alcohol, and organic acid are mixed to obtain a resin particle dispersion. The mixing can be performed by a general mixing method. However, if the components become uneven or the resin particles agglomerate, the feeling of use of the resin particle dispersion may be affected. It is preferable to dissolve or disperse in water, and dissolve or disperse the components that are easily compatible with alcohol, and then combine them together. In addition, the resin particle here is the wet powder obtained by the powdering process (IV) and / or the dried resin particle. When used in cosmetics, dry resin particles are preferred because bacteria may grow if moisture remains.

[Cosmetics]
The cosmetic of the present invention contains the resin particle dispersion.
The cosmetic of the present invention can contain other components to the extent that the dispersibility of the resin particle dispersion is not impaired. About the manufacturing method of the cosmetics of this invention, the mixing | blending of other components other than the manufacturing method of the said resin particle dispersion can be manufactured by a well-known method.

Other ingredients include, for example, perfume such as l-menthol; humectants such as glycerin, polymeric glycols (eg, polyethylene glycol and polypropylene glycol), mannitol, sorbitol and 1,3-butylene glycol; pH adjustment such as trisodium citrate Adsorbent such as cyclodextrin, disinfectant such as sodium aspartate, isopropylmethylphenol and benzalkonium chloride; deodorant such as ethylhexyl glycerin; astringent such as zinc sulfate and polyaluminum chloride; spray-type cosmetics In the case of use in the above, those commonly used in cosmetics such as propellants such as LPG, butane, pentane and dimethyl ether, preservatives, pigments, dyes, ultraviolet absorbers, and medicinal ingredients can be used.
Moreover, in order to assist the dispersibility of the resin particles, a surfactant may be added during the production of the resin particle dispersion. The surfactant is not particularly limited, and for example, cationic surfactants such as N-hydroxyethylpropylalkylamide nitrate, lauryltrimethylammonium choloride, lauryldimethylbenzylammonium chloride, benzalkonium chloride, benzethonium chloride; Anionic surfactants such as fatty acid salts, lauryl sulfate that is a sulfate ester salt, polyoxyethylene secondary alkyl ether sulfate ester salt, alkylbenzene sulfonate that is a sulfonate salt, dioctyl sulfosuccinate, and phosphate ester salts; Ethylene alkyl ethers, polyoxyethylene styrenated phenol ethers, polyoxyethylene alkyl amino ethers, polyethylene glycol fatty acid esters, polyols Siethylene polyoxypropylene glycols, glycerin fatty acid esters, polyoxyethylene castor oils, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkanolamides, polyoxyethylene fatty acid alkanolamides, adipic acid-diethanolamine Nonionic surfactants such as condensates; amphoteric surfactants such as alkylbetaines, amidopropylbetaines, alkylene oxide adduct betaines; methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, polyvinyl alcohol And water-soluble polymers such as

The cosmetic of the present invention is not particularly limited as long as it is a liquid cosmetic containing a resin particle dispersion, but includes cosmetics in general, such as quasi-drugs and pharmaceuticals, and can be selected according to the purpose. it can. For example, milky lotion, lotion, antiperspirant, packs, shave cream, nail polish cosmetics, hair washing cosmetics, hair dyes, essences, hair styling products, sunscreen products, suntan products, cleansing products, makeup cosmetics, body Examples include shampoo, aerosol, pre-shave lotion, body lotion and the like.

Hereinafter, the resin particles used for the measurement indicate dried resin particles unless otherwise specified.
(Measurement of average particle size)
It was measured by a wet measurement method using a laser diffraction particle size distribution measuring apparatus (Microtrack 9320HRA × 100, manufactured by Nikkiso Co., Ltd.), and the value of D50 was defined as an average particle diameter.

(Redispersibility evaluation)
The redispersibility evaluation of the settled particles was performed by the volume ratio of the sedimented layer volume formed from the particles calculated from the following mathematical formula (1) and the resin particle volume.
Volume ratio = sedimentation layer volume / resin particle volume (1)
(Settling layer volume)
100 ml of the resin particle dispersion test solution is put into a 100 ml cylindrical graduated cylinder and left to stand at 25 ° C. for 3 months with the lid covered with parafilm. It was calculated by reading from the cylinder scale.
(Particle volume)
The resin particle volume was calculated from the following mathematical formula (2). Resin particle volume = resin particle weight / true specific gravity of resin particle (2)

[Measurement of true specific gravity of resin particles]
The 100 ml volumetric flask is weighed (a), then the sample is added to a 1 part volumetric flask and weighed (b). To this, isopropyl alcohol is accurately added up to the 100 ml mark and the total weight is measured (c). Separately, an empty weight of the volumetric flask is weighed (x), and isopropyl alcohol is accurately added to the marked line to measure the total weight (y). These values are applied to the following mathematical formula (3) to calculate the specific gravity.
True specific gravity = (b−a) × (y−x) / {100 (y−x) − (c−b)} (3)

[Measurement of bulk specific gravity of resin particles]
The measurement was performed by a solid bulk specific gravity measurement method of a multi-functional type powder physical property measuring device (multi tester MT-1001k type, manufactured by Seishin Enterprise Co., Ltd.).
[Measurement of water content of resin particles]
It was measured using a Karl Fischer moisture meter (MKA-510N type, manufactured by Kyoto Electronics Industry Co., Ltd.).

[Measurement of water-soluble substance content]
20 g of resin particles are accurately measured (A) and added to 70 ml of ion exchange water and boiled at 100 ° C. for 5 minutes. After cooling to 20 ° C., the volume is adjusted to 100 ml using a volumetric flask and 20 ° C. ion-exchanged water (B). The dispersion is filtered through a membrane filter (Nitrocellulose, mesh opening 0.02 μm). Using a whole pipette, accurately collect 40 ml of this filtrate (C), transfer to a beaker whose weight has been accurately measured in advance (W ₀ ), evaporate to dryness on a water bath, and dry at 110 ° C. for 1 hour. . After cooling to room temperature in a desiccator so that the evaporation residue and the beaker do not absorb moisture, the weight of the beaker was again accurately measured (W ₁ ).
These values are applied to the following mathematical formula (4) to calculate the water-soluble substance content.
Water-soluble substance content = (W ₁ −W ₀ ) / {A × (C / B)} × 100 (% by weight) (4)

(Production example 1 of resin particles)
1 part adipic acid-diethanolamine condensate (concentration 50% by weight) as a low molecular nonionic surfactant, 600 parts ion-exchanged water, colloidal silica (Snowtex ST-20, concentration 20% by weight, manufactured by Nissan Chemical Co., Ltd.) 30 After adding a part and mixing, pH was adjusted to 3 and the aqueous dispersion medium was obtained.
190 parts of methyl methacrylate, 10 parts of ethylene glycol dimethacrylate and 1 part of dilauryl peroxide were mixed and dissolved to obtain an oily mixture.
The aqueous dispersion medium and oily mixture obtained above were stirred (5000 rpm × 5 min) with a TK homomixer 2.5 type (Primics) to prepare a suspension. The suspension was transferred to a 1.5 liter pressurized reactor and purged with nitrogen, then the initial reaction pressure was set to 0.3 MPa, and polymerization was performed at a polymerization temperature of 60 ° C. for 15 hours while stirring at 80 rpm. An aqueous dispersion medium containing was obtained.
The aqueous dispersion medium containing the polymer particles obtained above was adjusted to pH 12 with potassium hydroxide and heated at 65 ° C. for 3 hours to dissolve silica. Subsequently, the pH was readjusted to 7, isolated by filtration and dried to obtain resin particles A (water content 1.1% by weight). Table 1 shows the physical properties of the resin particles A.

(Production Example 2 of resin particles)
In 560 parts of ion-exchanged water, 70 parts of magnesium chloride hexahydrate and a low molecular amphoteric surfactant N-lauryl-N, N-bis (POE (2)) aminoacetic acid betaine aqueous solution (concentration 40% by weight) After 1.5 parts are added, 100 parts of an aqueous sodium hydroxide solution (concentration: 30% by weight) is gradually added dropwise so that the pH is about 9 to 10.5, and an aqueous dispersion medium containing finely divided magnesium hydroxide is added. Was prepared.
190 parts of methyl methacrylate, 10 parts of ethylene glycol dimethacrylate and 1 part of dilauryl peroxide were mixed and dissolved to obtain an oily mixture.
The aqueous dispersion medium and oily mixture obtained above were stirred (4000 rpm × 5 min) with a TK homomixer 2.5 type (Primics) to prepare a suspension. The suspension was transferred to a 1.5 liter pressurized reactor and purged with nitrogen, then the initial reaction pressure was set to 0.3 MPa, and polymerization was performed at a polymerization temperature of 60 ° C. for 15 hours while stirring at 80 rpm. An aqueous dispersion medium containing was obtained.
After the polymerization step, sulfuric acid was added to the aqueous dispersion medium containing the polymer particles, and the pH of the aqueous dispersion medium was lowered to 4 to dissolve magnesium hydroxide. Subsequently, the pH was readjusted to 7, isolated by filtration and dried to obtain resin particles B (moisture value 0.4% by weight). Table 1 shows the physical properties of the resin particles B.

(Production Example 3 of Resin Particles)
While heating 495 parts of ion-exchanged water to 70 ° C., 5 parts of methylcellulose (Methocel K-35LV, manufactured by Dow), which is a water-soluble polymer, was dissolved, completely dissolved and then cooled to prepare an aqueous dispersion medium. .
190 parts of methyl methacrylate, 10 parts of ethylene glycol dimethacrylate and 1 part of dilauryl peroxide were mixed and dissolved to obtain an oily mixture.
The aqueous dispersion medium and oily mixture obtained above were stirred (5000 rpm × 5 min) with a TK homomixer 2.5 type (Primics) to prepare a suspension. The suspension was transferred to a 1.5 liter pressurized reactor and purged with nitrogen, then the initial reaction pressure was set to 0.3 MPa, and polymerization was performed at a polymerization temperature of 60 ° C. for 15 hours while stirring at 80 rpm. An aqueous dispersion medium containing was obtained.
Next, the pH was adjusted to 7, isolated by filtration, and dried to obtain resin particles C (water content 1.2% by weight). Table 1 shows the physical properties of the resin particles C.

(Production Example 4 of Resin Particles)
Resin particles D were obtained in the same manner as in the particle production method example 2 except that the stirring condition for adjusting the suspension was changed to 4000 rpm × 5 min (moisture value 0.7 wt%). The physical properties of the resin particles D are shown in Table 1.

(Production Example 5 of resin particles)
Resin particles E were obtained in the same manner as in Example 1 of particle production except that the stirring conditions for adjusting the suspension were changed to 3000 rpm × 5 min (moisture value 1.0 wt%). The physical properties of the resin particles E are shown in Table 1.

(Production Example 6 of Resin Particles)
Resin particles F were obtained in the same manner as in the particle production method 1 except that the stirring condition for adjusting the suspension was changed to 2500 rpm × 5 min (moisture value 0.4 wt%). The physical properties of the resin particles F are shown in Table 1.
Resin particles G were prepared by mixing 1 part of resin particles A and 99 parts of resin particles F (moisture value 0.5 wt%).
(Production Example 7 of Resin Particles)
1 part of adipic acid-diethanolamine condensate (concentration 50% by weight) which is a low molecular nonionic surfactant, 600 parts of ion-exchanged water, colloidal silica (Snowtex ST-20, concentration 20% by weight, manufactured by Nissan Chemical Co., Ltd.) 25 After adding a part and mixing, pH was adjusted to 3 and the aqueous dispersion medium was obtained.
165 parts of methyl methacrylate, 20 parts of ethylene glycol dimethacrylate, 1 part of dilauryl peroxide and 15 parts of liquid paraffin were mixed and dissolved to obtain an oily mixture.
The aqueous dispersion medium and oily mixture obtained above were stirred (5000 rpm × 5 min) with a TK homomixer 2.5 type (Primics) to prepare a suspension. The suspension was transferred to a 1.5 liter pressurized reactor and purged with nitrogen, then the initial reaction pressure was set to 0.3 MPa, and polymerization was performed at a polymerization temperature of 60 ° C. for 15 hours while stirring at 80 rpm. An aqueous dispersion medium containing was obtained.
The aqueous dispersion medium containing the resin particles obtained above was adjusted to pH 7 without dissolving the colloidal silica, and was isolated by filtration and dried to obtain resin particles H (water content 1.2% by weight). Table 1 shows the physical properties of the resin particles H.
(Production Example 8 of Resin Particles)
An aqueous dispersion medium containing calcium phosphate was prepared by adding 10 parts of particulate calcium phosphate and 0.5 part of sodium lauryl sulfate as a low molecular anionic surfactant to 650 parts of ion-exchanged water.
190 parts of methyl methacrylate, 10 parts of ethylene glycol dimethacrylate, and 1 part of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and dissolved to obtain an oily mixture.
The aqueous dispersion medium and oily mixture obtained above were stirred (5500 rpm × 5 min) with a TK homomixer 2.5 type (Primics) to prepare a suspension. The suspension was transferred to a 1.5 liter pressurized reactor and purged with nitrogen, then the initial reaction pressure was 0.3 MPa, and polymerization was performed at a polymerization temperature of 65 ° C. for 15 hours while stirring at 80 rpm. An aqueous dispersion medium containing was obtained.
After the polymerization step, hydrochloric acid was added to the aqueous dispersion medium containing the polymer particles, and the pH of the aqueous dispersion medium was lowered to 2 to dissolve calcium phosphate. This was filtered and washed to remove calcium phosphate, then the pH was readjusted to 7, isolated by filtration and dried to obtain resin particles I (water content 0.6% by weight). Table 1 shows the physical properties of the resin particles I.
(Production Example 9 of Resin Particles)
Resin particles J were obtained in the same manner as in the particle production method 8 except that the calcium phosphate was changed to magnesium pyrophosphate (moisture value 0.7% by weight). Table 1 shows the physical properties of the resin particles J.

[Examples and Comparative Examples]
Examples 1 to 7 were mixed in the amounts shown in Table 2, Examples 8 to 14 were listed in Table 3, and Comparative Examples 1 to 5 were mixed in the amounts shown in Table 4. By applying ultrasonic waves for 5 minutes, resin particle dispersions were mixed. Was made. These resin particle dispersions were evaluated for redispersibility, and the results are shown in Tables 2 to 4.
Examples 5 and 7 are examples of cosmetics related to body lotions.
In Tables 2 to 4, EDTA4H aqueous solution represents ethylenediaminetetraacetic acid, EDTA2H2Na aqueous solution represents ethylenediaminetetraacetic acid disodium 2 hydrogen, and EDTA4Na represents ethylenediaminetetraacetic acid tetrasodium. A 5% by weight aqueous methylcellulose solution is Methocel K-35LV manufactured by Dow.

The redispersibility was evaluated based on the volume ratio of the sedimented bed volume and the particle volume. The larger the volume ratio, the better the redispersibility. Three or more were regarded as “Δ”, less than three as “x”, and “◯” or more as acceptable.
Usually, the redispersibility evaluation is performed by shaking the resin particle dispersion by hand, but this evaluation has a problem that there are individual differences and the results are not constant. Is possible.
When the volume ratio is 6 or more, the volume of the sedimentation layer is sufficiently large with respect to the particle volume. Therefore, the contact between the particles is small and blocking is difficult, and the redispersibility is kept good. The particles are evenly dispersed.

When the volume ratio is less than 6 to 5 or more, although there is some blocking between particles, it is a category in which redispersion is relatively easy, and redispersion is possible with 4 to 10 vibrations.
When the volume ratio is less than 5 to 3 or more, blocking of particles progresses with time, and redispersion requires labor to give vibrations of about 30 times.
When the volume ratio is less than 3, the particles are densely packed, and it is difficult to re-disperse to the extent that the particles are firmly blocked over time and vibrate by hand.

As can be seen from Tables 2 and 3, in Examples 1-14, water, alcohol and organic acid were included, and specific resin particles were dispersed. A resin particle dispersion in which particles were uniformly dispersed and excellent in redispersibility was obtained. Among them, in Example 10 using particles H having a low bulk specific gravity, the volume of the sedimentation layer was very large and the redispersibility was also good. On the other hand, in Example 9 in which the particles F having a high bulk specific gravity were used, the volume of the sedimentation layer was small in the examples.

Example 5 is a body lotion prescription (cosmetic). It was confirmed that there was no problem even if 1,3-butylene glycol as a humectant, 1-menthol as a fragrance, and trisodium citrate as a pH adjuster were added to the resin particle dispersion.

In Example 7, methylcellulose was further added to the resin particle dispersion from Example 5, but the redispersibility of the resin particles was hardly affected. This is presumably because methylcellulose is not taken into the resin particles because methylcellulose is added after the resin particles are prepared.

On the other hand, in Comparative Examples 1 to 5, when there is no organic acid (Comparative Example 1), when a completely neutralized organic acid is blended alone (Comparative Examples 2 and 4), the dispersant at the time of preparing the resin particles is When none of the inorganic component and the low molecular surfactant (Comparative Example 3), the volume ratio was less than 5.0, and it was difficult to redisperse the particles.
For these reasons, particles prepared using a dispersant containing inorganic particles and / or a low molecular surfactant exhibit high redispersibility in the presence of an organic acid, and the redispersibility decreases as the bulk specific gravity decreases. Was found to improve.

Since the resin particle dispersion of the present invention has redispersibility even after long-term storage, it is suitably applied to cosmetics containing resin particles.

Claims (10)

1. A step (I) of dispersing a polymerizable component containing a polymerizable monomer in an aqueous dispersion medium containing an inorganic component and a low molecular surfactant;
   Step (II) of polymerizing the polymerizable component to obtain resin particles;
   A pulverization step (IV) for obtaining a powder of resin particles from an aqueous dispersion medium containing the resin particles after the step (II);
   Including the mixing step (V) of mixing the resin particles, water, alcohol and organic acid after the step (IV) to obtain a resin particle dispersion;
   The organic acid is a hydroxy acid, a polyvalent carboxylic acid, an amino carboxylic acid, a phenol sulfonic acid, a salt partially neutralized with a hydroxy acid, a salt partially neutralized with a polycarboxylic acid, an amino carboxylic acid A method for producing a resin particle dispersion, which is at least one selected from a partially neutralized salt and a salt partially neutralized with phenolsulfonic acid.
2. The method for producing a resin particle dispersion according to claim 1, further comprising a step (III) of dissolving the inorganic component after the step (II).
3. The method for producing a resin particle dispersion according to claim 1 or 2, wherein the resin particles after step (IV) have an average particle diameter of 0.1 to 100 µm and a bulk specific gravity of 0.8 or less.
4. The polymerizable monomer is a (meth) acrylic acid ester monomer, a carboxyl group-containing monomer, a styrene monomer, a nitrile monomer, a vinyl monomer, or an amide group-containing monomer. The method for producing a resin particle dispersion according to any one of claims 1 to 3, which is at least one selected from maleimide monomers and vinylidene chloride.
5. 5. The inorganic component according to claim 1, wherein the inorganic component is at least one selected from colloidal silica, calcium phosphate, magnesium phosphate, magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium carbonate, calcium pyrophosphate and magnesium pyrophosphate. A method for producing the resin particle dispersion according to 1.
6. The hydroxy acid is at least one selected from lactic acid, tartaric acid, citric acid and malic acid, and the polyvalent carboxylic acid is selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid and fumaric acid And the aminocarboxylic acid is ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, dihydroxyethylethylenediaminediacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid and triethylenetetraamine hexaacetic acid. The resin particle fraction according to claim 1, wherein the resin particle fraction is at least one selected from acetic acid, and the phenolsulfonic acid is at least one selected from phenolsulfonic acid and benzotriazolylbutylphenolsulfonic acid. Method of manufacturing a liquid.
7. A resin particle dispersion obtained by blending resin particles, water, alcohol and organic acid,
   The average particle diameter of the resin particles is 0.1 to 100 μm, the bulk specific gravity of the resin particles is 0.8 or less,
   The water-soluble substance content of the resin particles measured by the following measurement method is 0.2% by weight or less,
   The organic acid is a hydroxy acid, a polyvalent carboxylic acid, an amino carboxylic acid, a phenol sulfonic acid, a salt partially neutralized with a hydroxy acid, a salt partially neutralized with a polycarboxylic acid, an amino carboxylic acid A resin particle dispersion which is at least one selected from a partially neutralized salt and a partially neutralized salt of phenolsulfonic acid.
   (Method for measuring content of water-soluble substance: 20 g of resin particles are precisely measured (A), added to 70 ml of ion-exchanged water and boiled for 5 minutes at 100 ° C. After cooling to 20 ° C., the volumetric flask and 20 ° C. (B) This dispersion is filtered through a membrane filter (made by Nitrocellulose, 0.02 μm mesh), and 40 ml of this filtrate is accurately collected using a whole pipette. Collect (C), transfer to a beaker that has been accurately weighed in advance (W ₀ ), evaporate to dryness in a water bath, and dry for 1 hour at 110 ° C. The residue from the evaporative dryness and the beaker do not absorb moisture Thus, after cooling to room temperature in the desiccator, when the weight of the beaker is precisely measured again (W ₁ ), the value calculated from the following formula (4) is taken as the water-soluble substance content.)
   Water-soluble substance content = (W ₁ −W ₀ ) / {A × (C / B)} × 100 (% by weight) (4)
8. A resin particle dispersion containing resin particles, water, alcohol and organic acid,
   The resin particles are resin particles obtained by dispersing a polymerizable component containing a polymerizable monomer in an aqueous dispersion medium containing an inorganic component and a low molecular surfactant, and polymerizing the polymerizable component.
   The organic acid is a hydroxy acid, a polyvalent carboxylic acid, an amino carboxylic acid, a salt in which a part of the hydroxy acid is neutralized, a salt in which a part of the polyvalent carboxylic acid is neutralized, and a part of the amino carboxylic acid. At least one selected from a salt that has been summed,
   Resin particle dispersion.
9. The resin particle dispersion according to claim 7 or 8, wherein the volume ratio defined by the following formula (1) is 5 or more.
   Volume ratio = sedimentation layer volume / resin particle volume (1)
   (In the formula (1), the sedimented bed volume means that 100 ml of the resin particle dispersion test solution is put into a 100 ml cylindrical graduated cylinder and left to stand at 25 ° C. for 3 months in a state covered with a parafilm. (The sediment volume formed from the settled particles is a value read from the scale of the graduated cylinder. The resin particle volume is a value calculated from the following mathematical formula (2).)
   Resin particle volume = resin particle weight / true specific gravity of resin particle (2)
10. A cosmetic comprising the resin particle dispersion according to any one of claims 7 to 9.