TWI557162B - Composite agglutinated resin particles and composition containing the particles - Google Patents

Description

Composite agglomerated resin particles and compositions containing the same

The present invention relates to a composite agglomerated resin particle. In particular, the present invention relates to an aggregated particle which can be easily redispersed into submicron-sized particles in an organic solvent while having excellent handleability.

To date, submicron-sized particles have been utilized in various fillers, toners, plastics, paints, inks, and the like. In such applications, good dispersibility of the microparticles is required, but submicron sized microparticles tend to agglomerate, and an extremely complicated and costly dispersion step is often required for redispersion. Therefore, in order to easily redisperse such submicron-sized particles, a method of surface treatment in accordance with various surfactants has been proposed.

For example, in Patent Document 1, it is proposed to use a surfactant in an aqueous medium to forcibly emulsify a polyurethane prepolymer and perform emulsion polymerization to produce a redispersibility of a particle diameter in the range of 100 nm to 100 μm. A method of excellent polyurethane-based emulsions. Examples of the surfactant include polyoxyethylene nonyl phenyl ether, polyoxyethylene nonyl phenyl ether, and polyoxyethylene lauryl ether. As a nonionic surfactant, it is described that a nonionic surfactant having an HLB value of 6 to 20 can be suitably used.

Further, in Patent Document 2, it is proposed to disperse a water-dispersible copolymer containing an ethylenically unsaturated carboxylic acid unit in an aqueous dispersion medium, which is a colloid and a carbon number of (meth)acrylic acid. Emulsified polymerization of unsaturated monomers such as alkyl esters of 1 to 18, styrene, glycidyl methacrylate, acrylamide, vinyl acetate, acrylonitrile, etc., to produce an average particle size in the range of 30 to 80 nm. A method of fine particle aqueous resin emulsion.

In Patent Document 3, it is described that the emulsion obtained by emulsifying and polymerizing an acrylic monomer in the presence of a polymer of an anionic, cationic or nonionic polymerizable emulsifier is spray-dried and excellent in redispersibility. Resin powder.

However, an emulsifier such as a surfactant is disadvantageous in that physical properties of various molded articles and coating materials are deteriorated, water resistance is deteriorated, coloring problems, and the like, and a low addition amount is generally expected.

Prior technical literature

Patent literature

Patent Document 1 Japanese Special Open 2000-136227

Patent Document 2 Japanese Special Open 11-29608

Patent Document 3 Japanese Special Open 7-53730

SUMMARY OF THE INVENTION An object of the present invention is to provide agglomerated microparticles which can be widely used in various applications represented by inks, paints or resin molded articles according to the state of the art of the prior art, with less impurities and operability. It is excellent, and when it is added to an organic solvent or kneaded in various resins, it is easily redispersed into primary particles.

The inventors of the present invention have found that the above object can be attained by the fact that the raw material agglomerated particles are aggregated with an oil-soluble ethylene-based polymer obtained by aggregating fine resin particles, and the present invention has been completed. That is, the object of the present invention is achieved by the following means.

[1] A composite agglomerated resin particle which is a raw material aggregated particle obtained by aggregating fine resin particles, and a composite resin particle of a polymer-soluble ethylene-based polymer, characterized in that all have an irregular shape and contain The fine resin particles maintain the shape before aggregation.

[2] The composite agglomerated resin particles according to [1], wherein the bulk density is 0.20 to 0.50 g/cm ³ .

[3] The composite agglomerated resin particles according to [1] or [2], wherein the fine resin particles contained therein have an average particle diameter of 100 to 600 nm as measured by an SEM image.

[4] The composite agglomerated resin particles according to any one of [1] to [3], wherein the 10% particle diameter when the particle diameter side cumulative particle size distribution is measured based on the volume is 1 μm or more.

[5] The composite agglomerated resin particles according to any one of [1] to [4], which does not contain a coagulant.

[6] The composite agglomerated resin particles according to any one of [1] to [5], which does not contain an emulsifier.

[7] The composite agglomerated resin particles according to any one of [1] to [6] wherein the content of the oil-soluble ethylene-based polymer is less than 15% by weight of the raw material aggregated particles.

[8] The composite agglomerated resin particles according to any one of [1] to [7] wherein the raw material agglomerated particles are used in an amount of from 90 to 100% by weight based on the total monomer weight, and the solubility in water is less than 3% by weight. The vinyl monomer and 0.25 to 3% by weight of a water-soluble polymerization initiator are formed by polymerization in water.

[9] The composite agglomerated resin particles according to any one of [1] to [8] wherein, in an aqueous dispersion containing agglomerated particles of a raw material in which fine resin particles are aggregated, an oil-soluble polymerization initiator is used for polymerization. The vinyl monomer is a composite of an oil-soluble vinyl polymer in the raw material agglomerated particles.

[10] A coating composition comprising the composite agglomerated resin particles according to any one of [1] to [9].

[11] An ink composition comprising the composite agglomerated resin particles according to any one of [1] to [9].

[12] A resin molded article comprising the composite agglomerated resin particles according to any one of [1] to [9].

Since the composite agglomerated resin particles of the present invention are excellent in redispersibility with respect to an organic solvent, the content of the aggregating agent or the emulsifier is small, and an appropriate aggregation state is maintained during the treatment, so that it is possible to easily obtain less impurities without using special equipment. A dispersion of nano resin particles. In addition, since the composite agglomerated resin particles of the present invention are not dispersed in the aqueous solvent and remain in a coagulated state, when added to an aqueous coating material or the like, it is possible to obtain an excellent matt effect irrespective of the viewing angle. Coating film.

[Formation of the Invention]

Hereinafter, the present invention will be described in detail. The composite agglomerated resin particles of the present invention are aggregated agglomerated particles in which a small amount of resin particles are aggregated, and an amorphous agglomerated resin particles in which an oil-soluble ethylene-based polymer is compounded. Such fine resin particles maintain the shape before aggregation in a state in which composite agglomerated resin particles are formed. Here, "the shape before the agglutination is maintained" is a state in which the fine resin particles are not welded to each other when the composite agglutination resin particles are observed by SEM, and the outline of the fine resin particles before aggregation is unclear, and the difference is maintained. A profile of the extent of a tiny resin particle. Therefore, for example, even if a part is in a welded state, the state in which the shape before the agglutination is maintained is limited to the fact that one of the fine resin particles can be distinguished on the SEM image.

Further, the composite agglomerated resin particles of the present invention are a raw material agglomerated particles in combination with an oil-soluble ethylene-based polymer. Here, the state of the composite is a state in which the oil-soluble ethylene-based polymer is adhered to the raw material aggregated particles by immersing the raw material aggregated particles in the oil-soluble ethylene-based polymer; and the raw material is aggregated. In the aqueous dispersion of the particles, the state obtained by polymerizing the raw material of the oil-soluble ethylene-based polymer into a vinyl monomer. In the state obtained as described above, the oil-soluble ethylene-based polymer adheres to the surface of the raw material aggregated particles and adheres to the gap between the aggregated fine resin particles, but it is considered that it does not reach the center portion of the raw material aggregated particles. Further, when viewed microscopically, it is considered that a part of the ethylene-based polymer is contained in the surface layer portion of the fine resin particles.

Further, the shape of the composite agglomerated resin particles of the present invention is amorphous. Here, the shape of the composite aggregated resin particles is not a detailed shape of the composite aggregated resin particles, but is intended for the entire shape. In addition, the "unshaped" is a state in which the shape of the individual aggregated resin particles is disordered. In such a state, most of the particles have a shape that is difficult to be regarded as a spherical shape, and the image of the particles as viewed from a single direction, that is, the periphery of the particle projection image has irregularities.

As a measure indicating the degree of the inmorphia, a circularity defined by the following formula can be used.

The circularity of the particle projection image = (the circumference of the circle of the same area as the projected area of the particle) / (the circumference of the particle projection image)

The circularity of the particle projection image = the circularity of the particle

That is, the circularity is 1 in the true circle, and becomes smaller as the degree of the inhomogeneity increases. In the composite agglomerated resin particles of the present invention, the circularity of the particles is preferably in the range of 0.50 to 0.94, preferably in the range of 0.70 to 0.90. In addition, the circularity can be measured using, for example, a flow particle image analyzer "FPIA-3000S" manufactured by Sysmex Co., Ltd.

In the composite aggregating resin particles of the present invention, the fine resin particles are maintained in a shape before aggregation, and the oil-soluble ethylene-based polymer is combined to exhibit easy handling and can be easily redispersed into fine resin particles in an organic solvent. The characteristics of the unit. In other words, the composite agglomerated resin particles of the present invention are in a dry state, and since the oil-soluble ethylene-based polymer can maintain the aggregated state, it is less likely to generate fine powder and is easy to handle. In addition, in an organic solvent, dissolution and removal of oil-soluble ethylene-based polymerization In the compound, the fine resin particles in the aggregated state are not welded to each other, or the portion to be welded is small, and can be easily separated into units of the fine resin particles by applying a force from the outside by stirring or the like.

Furthermore, the composite agglomerated resin particles of the present invention are in a state of being aggregated in water, are not easily separated, and are added to an aqueous coating material or the like to form a coating film, and are densely and non-deviationly present on the surface of the composite agglomerated resin particles. The faces of various angles are capable of scattering the incident light from any direction without mottle. Further, since the composite agglomerated resin particles of the present invention have an amorphous shape, incident light can be scattered to various directions. In other words, the matting effect of the coating film by the ordinary spherical particles is greatly changed with respect to the angle of the coating film, and when the composite agglomerated resin particles of the present invention having the above effects are used, It is expected that a high matte effect can be expected over a wide range of angles without a viewing angle. Specifically, all of the 20°, 60°, and 85° gloss values can be set to a low range of 0 to 30%.

In the composite agglomerated resin particles of the present invention, the bulk density is preferably 0.20 to 0.50 g/cm ³ , more preferably 0.25 to 0.40 g/cm ³ . Such a bulk density can be regarded as a measure for confirming the aggregation state of the fine resin particles. When the bulk density is too high, the fine resin particles are welded or strongly aggregated, and in this case, the fine resin particles are no longer dispersed.

In the composite agglomerated resin particles of the present invention, the 10% particle diameter in the case of accumulating the particle size distribution measurement results from the fine particles side is preferably 1 μm or more, more preferably 3 μm or more, and still more preferably 5 μm or more. When the 10% particle diameter is less than 1 μm, the number of fine particles is large, and the scattering of the particles is large, or the filter cloth is easily clogged during dehydration, and the operability is lowered.

Further, the volume average particle diameter of the composite agglomerated resin particles of the present invention is preferably 5 to 50 μm, more preferably 5 to 30 μm. When the average particle diameter is less than 5 μm, the surface unevenness of the coating film is less likely to occur, and when it is low, the sufficient matte effect cannot be exhibited. Further, when the average particle diameter is more than 50 μm, even if the added weight in the coating film is the same, the number of particles is reduced, and the number of irregularities on the surface of the coating film is reduced, and the matting effect when viewed from a low angle is insufficient. Further, it is easy to cause mottle at the time of coating, which not only causes the surface of the coating film to become rough, but also increases the possibility that the physical properties of the coating film are lowered.

Further, the composite agglomerated resin particles of the present invention are not desirably containing a coagulant. Here, the aggregating agent refers to an additive to be added to aggregate primary particles, and examples thereof include a polymer flocculating agent and an inorganic salt. Although there are many cases where the aggregating agent contains a coagulating agent, if agglomerated particles containing a large amount of aggregating agent are added to the coating material, the characteristics of the coating material or the coating film may be lowered. Further, there is a case where the redispersibility to an organic solvent is lowered.

Further, it is not desirable to contain an emulsifier. Here, the emulsifier means a surfactant. The emulsifier is usually added at the polymerization step or the like. If agglomerated particles containing a large amount of emulsifier are added to the coating, there is a case where the characteristics of the coating and the coating film are lowered. Further, there is a case where the property of maintaining the agglutination state in the aqueous solvent is lowered.

The average particle diameter of the fine resin particles contained in the composite agglomerated resin particles of the present invention is preferably 100 to 600 nm, preferably 150 to 500 nm. If the average particle diameter is too small, the cohesive force becomes strong, and the intended redispersibility cannot be obtained. On the other hand, if it is too large, there is a case where the aggregation state of the fine resin particles cannot be maintained. Further, from the viewpoint of the effect of light scattering, such an average particle diameter is preferred.

Further, the resin type of the fine resin particles is not particularly limited. For example, by selecting a resin having a refractive index difference as small as possible from the coating resin to which the composite agglomerated resin particles are added as a resin of the fine resin particles, the internal haze value of the obtained coating film can be lowered, and the transparency can be improved. On the contrary, by selecting a resin having a large refractive index difference as a resin of fine resin particles, the internal haze value of the obtained coating film can be improved, and various optical characteristics such as anti-glare and ultraviolet ray scattering can be obtained. Therefore, the kind of the resin of the fine resin particles can be arbitrarily selected depending on the purpose. In addition, when it is redispersed in an organic solvent, the solubility or swelling property of such an organic solvent is a consideration of the kind of the resin which selects a micro resin particle.

From the viewpoint of the properties required for the application, the resin which is a fine resin particle is preferably a vinyl resin which is rich in a monomer which can be used. Examples of the vinyl monomer which can be used in the case of using such a vinyl resin include methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, dimethylaminoethyl acrylate, and acrylic acid. Acrylate monomer such as diethylaminoethyl ester; methacrylate monomer such as methyl methacrylate, ethyl methacrylate, lauryl methacrylate or dimethylaminoethyl methacrylate a styrene monomer such as styrene or p-methylstyrene; an alkyl vinyl ether such as methyl vinyl ether or ethyl vinyl ether; or a vinyl ester series such as vinyl acetate or vinyl butyrate; N-alkyl substituted (meth) acrylamide such as N-methyl acrylamide or N-ethyl acrylamide; nitrile monomer such as acrylonitrile or methacrylonitrile; divinyl benzene , ethylene glycol di(meth)acrylate, polyethylene glycol mono(meth)acrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethyl A polyfunctional monomer such as a acrylate or the like. These monomers may be used alone or in combination of two or more.

The raw material agglomerated particles used in the present invention are obtained by aggregating the above-mentioned fine resin particles, and can be obtained, for example, by agglomerating a dispersion of fine resin particles obtained by emulsion polymerization and adding a coagulant. However, a vinyl monomer having a solubility in water of less than 3% by weight, such as methyl methacrylate or ethylene glycol dimethacrylate, is preferably used as the raw material agglomerated particles obtained by the production method described later. It is possible to use any one which does not contain an emulsifier and an aggregating agent.

Moreover, the particle size of the fine resin particles in the present invention can be adjusted depending on the polymerization conditions and the amount of the emulsifier. Similarly, the particle diameter of the agglomerated particles of the raw material of the present invention can also be adjusted depending on the polymerization conditions when the particles are aggregated in the production of the raw material and when the aggregating agent is used. Moreover, in the method for producing the raw material aggregated particles to be described later, the particle diameter of the raw material aggregated particles can be adjusted by the addition of polyvinyl alcohol. Specifically, in the polymerization system of the vinyl monomer, the polymerization is carried out by adding 0.001 to 1 part by weight, preferably 0.01 to 0.1 part by weight, based on 100 parts by weight of the monomer. When polyvinyl alcohol is added in such a range, the particle diameter of the raw material aggregated particles tends to be smaller as compared with when it is not added. This is not considered to be caused by a slight suppression of aggregation of fine resin particles generated by polymerization.

The oil-soluble ethylene-based polymer used in the present invention is a substance which maintains the aggregated state of the composite aggregated resin particles of the present invention in a dry state or in water as described above. Further, by dissolving and removing the oil-soluble vinyl polymer in an organic solvent, the complex of the present invention can be easily redispersed. The aggregated resin particles are a unit of fine resin particles. When the oil-soluble ethylene-based polymer is water-insoluble and further redispersed in an organic solvent, it is desirable to be a substance which does not have a crosslinked structure and is easily dissolved in the organic solvent to be used. Therefore, when an oil-soluble vinyl polymer is selected, it is possible to refer to, for example, a solubility parameter of an organic solvent used for redispersion.

Further, the oil-soluble ethylene-based polymer to be used in the present invention is a raw material in which an ethylene-based monomer is polymerized by using an oil-soluble polymerization initiator in an aqueous dispersion containing raw material aggregated particles. The aggregated particles are composited. In this case, as the vinyl-based monomer to be used, it is of course possible to obtain an oil-soluble ethylene-based polymer to be compounded, but the affinity between the vinyl-based monomer and the fine resin particles should also be considered. In other words, when the vinyl monomer is added, when the fine resin particles are dissolved or rapidly swollen, the shape before the aggregation of the fine resin particles cannot be maintained, or the fine resin particles are bonded or combined with each other, and the red resin particles cannot be redispersed. The unit of the fine resin particles or the optical characteristics such as the matting performance are lowered.

Therefore, from the viewpoint of maintaining the shape of the fine resin particles, it is necessary to consider the type and amount of the vinyl monomer of the oil-soluble ethylene-based polymer used in the present invention, and to introduce the crosslinked structure into the fine resin in advance. The particles, while inhibiting dissolution and swelling, can amplify the range of choice of vinyl monomers.

As the oil-soluble ethylene-based polymer to be used in the above-mentioned invention, a single polymer and a copolymer such as a vinyl monomer which can be used for the resin of the above-mentioned fine resin particles can be exemplified. A monomer having a plurality of double bonds, which is reduced in oil solubility by polymerization and formation of a crosslinked structure Since the solubility of the vinyl polymer is required, it is desirable to use it completely in the organic solvent, and it is not necessary to use it at all, even if it is used. Specifically, poly(meth)acrylate, polystyrene, polyvinyl acetate, a copolymer of a plurality of (meth)acrylates, and the like can be exemplified. In addition, the term "(meth)acrylic acid" means both "methacrylic acid" and "acrylic acid".

Further, the upper limit of the amount of the oil-soluble ethylene-based polymer used in the present invention in the raw material aggregated particles is preferably 15% by weight or less, more preferably 5% by weight, still more preferably 3% by weight, based on the aggregated particles of the raw material. the following. When the oil-soluble ethylene-based polymer is 15% by weight or more, in addition to being dissolved in an organic solvent, it is difficult to redisperse, and if a large amount of dissolved oil-soluble ethylene-based polymer is contained in the redispersion, There is a tendency to cause re-dispersion characteristics and the like depending on the situation. In addition, when the ethylene-based monomer is added and polymerized to make the oil-soluble ethylene-based polymer 15% by weight or more, the fine resin particles are swollen by the vinyl monomer, and the fine resin particles are bonded or bonded to each other. Redispersion in an organic solvent becomes difficult.

In addition, the lower limit of the amount of the raw material agglomerated particles in combination with the oil-soluble ethylene-based polymer is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and still more preferably 0.5% by weight or more. When the oil-soluble ethylene-based polymer is less than 0.01% by weight, the effect of maintaining the aggregation of the oil-soluble ethylene-based polymer is hardly obtained, and fine powder is likely to be generated, which may cause difficulty in handling.

The composite agglomerated resin particles of the present invention described above can be obtained by compounding oil-soluble ethylene-based polymers with raw material agglomerated particles. In the raw material agglomerated particles, from the viewpoint of the properties required for the composite resin particles of the present invention, it is desirable that the fine resin particles maintain a shape before aggregation and simultaneously aggregate. The method for producing the raw material aggregated particles is not particularly limited as long as the desired raw material aggregated particles can be obtained. As one of the examples, the raw material aggregated particles can be formed by dispersing the droplets of the vinyl monomer in water in which the water-soluble polymerization initiator is dissolved, and performing polymerization by heating and stirring. In this method, raw material agglomerated particles in which fine resin particles are aggregated can be obtained without adding a special operation or an additive. The raw material aggregated particles thus obtained can also be adjusted to an arbitrary particle diameter by pulverization and classification.

As the vinyl monomer used in such a method, it is desirable to use a vinyl monomer which is preferably less than 3% by weight in water at 20 ° C and preferably less than 2% by weight, based on the total monomer weight. In other words, 90% by weight or more and 95% by weight or more of such a vinyl monomer are used. Typical examples of such a vinyl monomer include acrylate monomers such as methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate; methyl methacrylate and methyl methacrylate; a methacrylate monomer such as ethyl acrylate or lauryl methacrylate; a styrene monomer such as styrene or p-methylstyrene; or an alkyl ether such as methyl vinyl ether or ethyl vinyl ether. Vinyl ether; vinyl ester monomer such as vinyl acetate or vinyl butyrate; divinylbenzene, ethylene glycol di(meth)acrylate, polyethylene glycol mono(meth)acrylate, three Hydroxymethylpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and the like. When such a monomer is less than 90% by weight, fine resin particles may not aggregate. It is thought to be due to the solubility in water. More than 3% by weight of the vinyl monomer is used in a large amount, and such a monomer is preferentially polymerized to function as a dispersing agent. Further, the ratio of the total monomer weight to the total weight placed is desirably 5 to 35% by weight.

As a polymerization initiator, if it is a water-soluble polymerization initiator, any type of initiator such as an azo system, a persulfate system, a peroxide system, or a redox system can be used, even in the case of light. Both initiators and thermal initiators can be used. As a representative example, 2,2'-azobis(2-methylpropionamidine) dihydrochloride (2,2'-azobis(2-methyl propionamidine) dihydrochloride), 2,2'-even Nitrogen bis(1-imino-1-pyrrolidino-2-methylpropane)dih ydrochloride Oxidation of t-butyl hydroperoxide, ammonium persulfate, potassium persulfate, hydrogen peroxide / iron (II) ion system, and the like.

Such a water-soluble polymerization initiator is preferably used in an amount of 0.25 to 3% by weight and preferably 0.25 to 2% by weight based on the total monomer weight. Within this range, it is possible to obtain a state in which the fine resin particles are in a state of aggregation, and it is not bulky.

As described above, the raw material aggregated particles used in the present invention can be obtained, but if necessary, the pulverization treatment can be carried out to adjust the desired particle diameter. A special apparatus is not required in such a pulverization process, and a general pulverization such as a blade mill, a banbury mixer, a kneader mixer, or a roll can be used. Device. Further, in the pulverization treatment, it is not necessary to dry the particles, and the pulverization can be carried out in a wet state such as after completion of the polymerization.

Further, in the above-described production method, it is possible to obtain a raw material aggregated particle in an appropriate agglomerated state without using an emulsifier or a coagulant, and it is an appropriate method to obtain the composite aggregated resin particle of the present invention. However, in the present production method, an emulsifier or an aggregating agent can also be used as needed.

In addition, as a method of compounding the oil-soluble ethylene-based polymer, a method of polymerizing a vinyl-based monomer using an oil-soluble polymerization initiator in an aqueous dispersion containing raw material aggregated particles can be exemplified.

In such a method, as the aqueous dispersion containing the raw material aggregated particles, in the method for producing the raw material aggregated particles described above, a dispersion liquid of the aggregated particles of the raw material produced by the polymerization can be used as it is. Further, as a method of adding a vinyl monomer and an oil-soluble polymerization initiator to an aqueous dispersion, a method in which each of them is added and a solution in which an oil-soluble polymerization initiator is dissolved in a vinyl monomer may be added. The method of adding a solution diluted with a solvent according to the above two methods, or the like, may be carried out in a single amount at a time or a small amount may be gradually dropped while performing polymerization. In addition, the amount of the vinyl monomer to be added is preferably less than 15% by weight, preferably less than 5, based on the amount of the raw material aggregated particles in combination with the oil-soluble ethylene-based polymer. The weight %, more preferably 3% by weight or less, is the upper limit. The raw material agglomerated particles are preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and still more preferably 0.5% by weight or more.

In addition, when the oil-soluble ethylene-based polymer is compounded, it is desirable that the fine resin particles constituting the raw material aggregated particles have a crosslinked structure. When there is no cross-linking structure, there is a vinyl series added by The case where the fine resin particles are dissolved in the body, and the composite agglomerated resin particles of the present invention cannot be obtained. In the case of the method of producing the crosslinked structure, the method of producing a raw material aggregated particle or the like as described above may be a method of copolymerizing a vinyl monomer having two or more vinyl groups.

Although the use of the composite agglomerated resin particles of the present invention is described below, such a use is one of the examples, and the composite agglomerated resin particles of the present invention can also be used in other wide-ranging applications.

The composite agglomerated resin particles of the present invention can be used in addition to a coating material or an ink composition, and can also be used in a resin molded article or the like. As a method of producing a coating material or an ink composition, a method of adding the composite agglomerated resin particles of the present invention and a binder resin to an organic solvent can be mentioned. The above-mentioned binder resin is not particularly limited, and examples thereof include a thermoplastic resin, a thermosetting resin, and a photocurable resin. Specific examples thereof include an acrylic resin, a polyester resin, polyvinyl chloride, and a polyurethane. Polyoxygenated resin, melamine resin, and the like. Further, when the transparency of the coating film is imparted, an acrylic resin, an acrylic acid-polyoxymethylene resin or the like is preferably used.

The organic solvent is not particularly limited as long as it is a resin for dissolving the binder, and examples thereof include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexane, and ethylene glycol monomethyl ether (methyl group). "methyl cellosolve", ethylene glycol monoethyl ether (ethyl cellosolve), ethyl acetate, butyl acetate, isopropanol, acetone, anisole, etc. They may be used alone or in combination of two or more. Further, various additives such as a coloring agent such as a leveling agent, a surface modifier, an antifoaming agent, and a pigment can be added to the coating material and the ink composition.

In the above composition, for example, the agglomerated resin particles of the present invention are added after dissolving the binder resin in an organic solvent, and a sand mill, a ball mill, an attritor, a high-speed rotary stirring device, a three-roll mixer, or the like can also be used. It is produced by dispersion and mixing.

The composite agglomerated resin particles of the present invention are not limited to the solvent-based paints and ink compositions described above, and can be used in various coating materials and ink compositions such as solvent-free, water-based, and powder-based materials. In particular, when it is added to an aqueous coating material, as described above, since the agglutination state is maintained without being separated, it is possible to effectively exhibit excellent matting properties in the coating film.

In addition, the composite agglomerated resin particles of the present invention are molded by kneading with a thermoplastic or thermosetting matrix resin, and a resin molded article containing fine resin particles redispersed into primary particles can be produced. As the matrix resin, a resin having excellent transparency, weather resistance, and rigidity, such as a polymethyl methacrylate resin, an MS resin, a polycarbonate resin, or a polyester resin, is preferably used.

In the resin molded article of the present invention, a resin is mixed with a composite agglomerated resin particle by a mixer, and after kneading in a melt kneader, a sheet-shaped resin molded article can be obtained by extrusion. Further, after melt-kneading, pellets are formed and taken out, and the pellets can be melted and then injection-molded to obtain the above-mentioned molded article.

[Examples]

Hereinafter, the effects of the present invention will be described based on examples and comparative examples, but the scope of the present invention is not limited only by the examples.

(1) Roundness, volume average particle size and 10% particle size of the sample particles

The circularity, volume average particle diameter, and 10% particle diameter of the particles defined by the above were measured by a flow type particle image analyzer (FPIA-3000S: manufactured by Sysmex Co., Ltd.). Further, the 10% particle diameter is a value obtained by measuring the particle size distribution measurement result from the particle side on a volume basis.

(2) Average particle size of fine resin particles

In the SEM image of the sample particles, 20 fine resin particles were arbitrarily selected, and the diameters were measured, and the average value was calculated.

(3) Bulk density

The particles were filled in a known volume of container A (cm ³ ), and the weight B (g) was measured to calculate the bulk density.

Bulk density (g/cm ³ ) = B(g) / A(cm ³ )

(4) Redispersibility

10 parts by weight of the sample particles and 50 parts by weight of methyl ethyl ketone were added to 100 parts by weight of an oil-based topcoat coating (ACRYDIC (acrylic resin, resin concentration: 30% by weight): DIC Corporation) Stir for 10 minutes with a homogenizer. The obtained coating composition was applied to a PET film (Cosmo Shine #A4300 (thickness: 100 μm: manufactured by Toyobo Co., Ltd.) as a coater #26, and then dried in a hot air dryer at 60 ° C for 30 minutes. The coating film was observed using an optical microscope, and the redispersibility was judged based on the criteria shown below.

○: no aggregated particles

△: slightly agglomerated particles

×: There are agglomerated particles

(5) 20°, 60°, 85° gloss values

3 parts by weight of the sample particles and 50 parts by weight of water were added to 100 parts by weight of the water-based top coat paint (water-soluble polish paint (acrylic resin, resin concentration: 30% by weight): manufactured by Shinshin Co., Ltd.) to Stir the machine for 10 minutes. Using the obtained coating composition, a coating film sample was prepared on a concealing rate test paper, and measured by a gloss meter (VG 2000: manufactured by Nippon Denshoku Co., Ltd.).

[Example 1]

300 parts by weight of water was placed in the reaction tank to dissolve 0.6 parts by weight of 2,2'-azobis(1-imino-1-pyrrolidinyl-2-methylpropane) dihydrochloride (2). 2'-azobis(1-imino-1-pyrrolidino-2-methylpropane)dihydrochloride) as a polymerization initiator. Subsequently, 99 parts by weight of methyl methacrylate and 1 part by weight of ethylene glycol methacrylate were added as a monomer, and the mixture was reacted at 45 ° C for 2 hours while stirring to obtain an aqueous dispersion of the raw material aggregated particles. Next, in the aqueous dispersion, 3 parts by weight of methyl methacrylate and 0.3 parts by weight of 2,2'-azobis(2-methylpentane) were added in an amount of 100 parts by weight of the solid content of the aqueous dispersion. Nitrile) was again reacted at 45 ° C for 2 hours. Subsequently, after classification for removing coarse particles, the composite agglomerated resin particles of Example 1 were obtained by centrifugal dehydration. Table 1 shows the results of measuring the characteristics of the particles. Further, Fig. 1 and Fig. 2 show SEM images of the particles.

[Embodiment 2]

300 parts by weight of water was placed in the reaction vessel, and 0.6 parts by weight of potassium persulfate was dissolved as a polymerization initiator. Then add 99 parts by weight of methyl Methyl acrylate and 1 part by weight of ethylene glycol methacrylate were reacted as a monomer while stirring at 45 ° C for 2 hours to obtain an aqueous dispersion of the raw material aggregated particles. Next, in the aqueous dispersion, 3 parts by weight of styrene and 0.3 parts by weight of 2,2'-azobis(2-methylvaleronitrile) were added in an amount of 100 parts by weight of the solid content of the aqueous dispersion, and again The reaction was carried out at 45 ° C for 2 hours. Subsequently, after fractionation for removing coarse particles, the composite agglomerated resin particles of Example 2 were obtained by centrifugal desorption. Table 1 shows the results of measuring the characteristics of the particles.

[Example 3]

In the same manner as in Example 1, except that 3 parts by weight of methyl methacrylate added to the aqueous dispersion of the raw material aggregated particles was changed to 3 parts by weight of vinyl acetate, Example 3 was obtained. Composite agglomerated resin particles. Table 1 shows the results of measuring the characteristics of the particles.

[Example 4]

In the same manner as in Example 1, except that 3 parts by weight of methyl methacrylate added to the aqueous dispersion of the raw material aggregated particles was changed to 3 parts by weight of 2-ethylhexyl acrylate. The composite agglomerated resin particles of Example 4 were obtained. Table 1 shows the results of measuring the characteristics of the particles.

[Example 5]

Example 1 was carried out in the same manner as in Example 1 except that 3 parts by weight of methyl methacrylate added to the aqueous dispersion of the raw material aggregated particles was changed to 0.1 part by weight of methyl methacrylate. 5 composite agglomerated resin particles. Table 1 shows the results of measuring the characteristics of the particles.

[Embodiment 6]

Example 1 was carried out in the same manner as in Example 1 except that 3 parts by weight of methyl methacrylate added to the aqueous dispersion of the raw material aggregated particles was changed to 15 parts by weight of methyl methacrylate. 6 composite agglomerated resin particles. Table 1 shows the results of measuring the characteristics of the particles.

[Embodiment 7]

In the same manner as in Example 1, except that 1 part by weight of ethylene glycol methacrylate used for the synthesis of the raw material aggregated particles was changed to 1 part by weight of trimethylolpropane trimethacrylate. The composite agglomerated resin particles of Example 7 were obtained. Table 1 shows the results of measuring the characteristics of the particles.

[Embodiment 8]

In the first embodiment, the composite agglomerated resin particles of Example 8 were obtained in the same manner as in Example 1 except that 0.04 parts by weight of polyvinyl alcohol was added before the reaction of the raw material aggregated particles. Table 1 shows the results of measuring the characteristics of the particles.

[Comparative Example 1]

After fractionation of the coarse particles of the aqueous dispersion for removing the raw material aggregate particles of Example 1, the particles of Comparative Example 1 were obtained by centrifugal dehydration. Table 1 shows the results of measuring the characteristics of the particles.

[Comparative Example 2]

In the same manner as in Example 1, except that 3 parts by weight of methyl methacrylate added to the aqueous dispersion of the raw material aggregated particles was changed to 20 parts by weight of methyl methacrylate, a comparison was obtained. The particles of Example 2. Table 1 shows the results of measuring the characteristics of the particles.

[Reference Example 1]

In the method for producing the raw material resin particles of Example 1, except that 85 parts by weight of methyl methacrylate and 15 parts by weight of 2-hydroxyethyl methacrylate were used, 99 parts by weight of methyl methacrylate was used instead. After the polymerization was carried out in the same manner as in the case of 1 part by weight of ethylene glycol methacrylate, an aqueous dispersion of fine resin particles could be obtained, but the raw material aggregated particles could not be obtained.

In Examples 1 to 8, it is possible to obtain composite agglomerated resin particles having excellent redispersibility in an organic solvent and having a small amount of fine powder. Further, when the particles are added to the water-based paint to form a coating film, the gloss values at any angles of 20°, 60°, and 85° are all in a low range, and it is possible to obtain a high gloss value without increasing the viewing angle. Extinction effect. In addition, although the particles of Comparative Example 1 were 10% The particle size is small, but it does not combine with a vinyl polymer, and it is considered that the agglomerated particles are separated and the fine powder is increased. Therefore, the operability of the particles such as scattering at the time of classification and blending is deteriorated. In the particle system of Comparative Example 2, since the amount of the ethylene-based polymer compounded was large, the fine resin particles were welded to each other, and the redispersibility was poor.

Fig. 1 is a SEM image showing the composite agglomerated resin particles obtained in Example 1.

Fig. 2 is a SEM image showing fine resin particles in the composite agglomerated resin particles obtained in Example 1.

Claims (11)

A composite agglomerated resin particle which is a raw material aggregated particle obtained by aggregating fine resin particles, and a composite resin particle of an oil-soluble ethylene polymer, characterized in that the entire shape has an amorphous shape and the fine resin particle is contained therein. The shape before the aggregation was maintained, and the content of the oil-soluble ethylene-based polymer was less than 15% by weight of the raw material aggregated particles. The composite agglomerated resin particles according to claim 1, wherein the bulk density is 0.20 to 0.50 g/cm ³ . The composite agglomerated resin particles according to claim 1 or 2, wherein the fine resin particles contained therein have an average particle diameter of 100 to 600 nm as measured by an SEM image. The composite agglomerated resin particles according to claim 1 or 2, wherein the 10% particle diameter when the particle size distribution measurement result is obtained from the particle side on a volume basis is 1 μm or more. The composite agglomerated resin particles of claim 1 or 2, which do not contain a coagulant. The composite agglomerated resin particles of claim 1 or 2, which do not contain an emulsifier. The composite agglomerated resin particles according to claim 1 or 2, wherein the raw material agglomerated particles are used in an amount of from 90 to 100% by weight, based on the total monomer weight, of a vinyl monomer having a solubility in water of less than 3% by weight. And 0.25 to 3% by weight of a water-soluble polymerization initiator, which is formed by polymerization in water. Such as the composite agglomerated resin particles of claim 1 or 2, In the aqueous dispersion containing the agglomerated particles of the raw material in which the fine resin particles are aggregated, the ethylenic monomer is polymerized using an oil-soluble polymerization initiator, whereby the oil-soluble ethylene-based polymer is compounded on the raw material agglomerated particles. A coating composition comprising the composite agglomerated resin particles according to any one of claims 1 to 8. An ink composition comprising the composite agglomerated resin particles according to any one of claims 1 to 8. A resin molded article comprising the composite agglomerated resin particles according to any one of claims 1 to 8.