JP2015147827A - Black colored porous resin beads, method for producing same, and product with texture of suppressed glossiness using the resin beads - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide black colored porous resin beads in which the resin beads themselves are colored black and, moreover, a particle surface is roughened and porous, which therefore, when used by adding the resin beads into a coating film and the like, can realize a uniform reflection reducing effect and, moreover, can enable a design expression of high jet-black feeling.SOLUTION: There is provided porous resin particles formed by suspension polymerization of a monomer mixture containing a plurality of monomers having copolymerizable functional groups in a state where at least a black pigment, a polymeric dispersant, and an organic solvent, which can dissolve the polymeric dispersant, are present. In the porous resin particles, there is contained the black pigment, and at least a surface thereof is roughened.

Description

  The present invention relates to black porous resin beads which are porous resin particles containing a black pigment, a method for producing the same, and uses thereof. More specifically, it is a black porous resin bead with high designability that reduces reflected light having at least a roughened surface and a method for producing the same, and products in the field requiring such functionality, for example, molding It relates to products such as body, film, coating agent or resin composition.

  Conventionally, resin beads are generally used as an optical adjustment functional material such as a matting additive such as a paint, a light diffusing agent such as a liquid crystal light diffusion plate, or a light diffusing agent for an antiglare film of a display material. . For example, when the glossiness is adjusted by adding matte resin beads to the paint, the formed coating film has a texture that suppresses the glossiness and is preferred as an excellent design expression. In addition, automobile interior parts are painted on the surface, but in consideration of anti-glare to the driver, the paint film has a matte finish using resin beads to improve safety. For this purpose, a function to reduce reflected light has been achieved.

  As described above, resin beads have been conventionally used as a light reflection and diffusion regulator. For example, as an example of a method of adjusting the optical reflection characteristics macroscopically by forming micro unevenness on the coating surface with resin beads added to the coating material, specific resin particles are blended in the coating material and the coating film. The coating composition etc. which were made are proposed (for example, refer patent document 1). Furthermore, the resin beads to be added are made porous, and various kinds of methods such as a method of using specific porous resin beads capable of adjusting light diffusibility for cosmetic materials and optical films (for example, see Patent Document 2). Proposals have been made.

JP 2003-55597 A JP 2013-227535 A

  However, the paint containing the resin particles described above has an effect of reducing the reflected light from the uneven coating film to some extent, but the reflected light itself generated from the surface of the resin particles cannot be prevented. The reduction effect was not sufficient. Further, according to the study of the present inventor, when using porous resin beads that improve light diffusibility, although there is an effect of diffusing light compared to a coating film to which resin particles that are not porous are added, Since the resin beads themselves are not colored, there are the following problems. For example, when the coating film is colored black, if a black pigment and uncolored porous resin beads are used in combination, the difference in particle diameter may cause a mottled and uneven color distribution during leveling. In addition, there is a problem that the black pigment to be used is buried in the porous part of the resin particles, which is difficult to use for optical material applications that require a uniform reflected light reduction effect, and is not uniform in the field that requires design properties As a result, there was a problem that the desired excellent design expression could not be obtained.

  From the above situation, it is useful for the inventor to develop black porous resin beads that can be used to realize a product with excellent reflected light reduction effect and jet blackness in design. It came to recognize that there was.

Therefore, the present invention has been made in view of such a situation, and the porous resin beads themselves are colored black, and by adding this, when used for a coating film, etc. Porous resin beads that can realize a uniform reflected light reduction effect, and that can express a design with a high jetness, a method for producing the porous resin beads, and various products having excellent characteristics using the same. The purpose is to provide.
In the present invention, the term “porous” means that at least the surface of the resin particle is roughened, the surface has light scattering properties, and has an effect of reducing reflected light. . More specifically, it means that the 60 ° reflectance is 3.0 or less.

  The above object is achieved by the present invention described below. That is, the present invention provides a monomer mixture comprising a plurality of monomers having a copolymerizable functional group, at least a black pigment, a polymer dispersant, and an organic solvent capable of dissolving the polymer dispersant. Porous resin particles formed by suspension polymerization in the presence of a black pigment, and at least the surface thereof is roughened. A black porous resin bead is provided.

  The following are mentioned as a preferable form of said porous resin bead. That is, the monomer having a copolymerizable functional group is a (meth) acrylate type; the monomer mixture having a plurality of copolymerizable functional groups on a mass basis The black pigment is selected from the group consisting of carbon black, perylene black, azomethine azo black, aniline black, iron black, titanium black, and composite oxide black; the composite oxide black Containing at least one element selected from the group consisting of Cu, Fe, or Mn; the monomer mixture is a monomer having a plurality of copolymerizable functional groups, And hexanediol diacrylate; the volume average particle diameter of the porous resin particles is 20 μm or less.

  As another embodiment, the present invention provides a black pigment, a monomer mixture containing a plurality of monomers having a copolymerizable functional group, a polymer dispersant, an organic solvent capable of dissolving the polymer dispersant, and A black porous resin particle having at least a roughened particle surface is produced by suspension polymerization of a polymerizable solution containing a polymerization initiator in an aqueous phase in which a dispersion stabilizer is dissolved. A method for producing black porous resin beads is provided.

  The following are mentioned as a preferable form of the manufacturing method of said porous resin bead. That is, when the polymerizable solution is prepared, the polymer dispersant is dissolved in the organic solvent, and the polymerizable solution is prepared using the obtained dissolved material; the polymerizable solution is prepared. In advance, a dispersion is prepared in advance using the black pigment, the polymer dispersant, and, if necessary, the monomer having the copolymerizable functional group, and polymerization is performed using the obtained dispersion. The organic solvent has a solubility in water of 3 to 100 parts by mass with respect to 100 parts by mass of water; the organic solvent has a solubility in water; It is at least one selected from the group consisting of a ketone solvent, an ether solvent, a glycol ether solvent, and a glycol ester solvent; the organic solvent is propylene glycol monomethyl ether acetate It is below.

  As another embodiment, the present invention is a product of any of a molded product, a film, a coating agent, a paint, a pigment dispersion, or a resin composition, and includes any one of the porous resin beads described above. Providing products with a low-gloss texture.

  According to the present invention, since the resin beads themselves are colored black and the particle surface is a porous surface roughened, the resin beads are added to form a coating film. A porous porous resin bead that can achieve a uniform reflected light reduction effect and that enables a design expression with a high jet black feeling, a manufacturing method that can stably manufacture this porous resin bead, and Thus, it is possible to provide various products having excellent characteristics using such porous resin beads.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments of the present invention.
The present inventor has made various studies on porous resin beads that have a uniform reflected light reduction effect. As a result, the porous resin beads containing a black pigment containing colored resin beads reduce reflected light more uniformly. The effect can be imparted, and of course, when the black pigment and uncolored porous resin beads are used in combination, the difference in particle size between the two causes a mottled and uneven coloring. The inventors have found that the distribution does not occur and found that the problems of the prior art mentioned above can be solved brilliantly, and have reached the present invention.

  The porous resin beads of the present invention are prepared by dissolving a monomer mixture containing a plurality of monomers having a copolymerizable functional group, at least a black pigment, a polymer dispersant, and the polymer dispersant. Formed from a copolymer obtained by suspension polymerization in the presence of an organic solvent to be obtained, the properties of which include a black pigment in the porous resin particles and a rough surface. It is characterized by being surfaced. The resin component constituting the resin beads of the present invention is not particularly limited, and any known resin that can be used can be used. For example, considering the purpose of use, a material suitable for a paint, a film, or a coating agent may be used as appropriate. Specifically, for example, (meth) acrylate resin, styrene resin, olefin resin, polyester resin, polyurethane resin, poly (thio) ether resin, polysulfone resin, polyimide resin, polycarbonate resin, Examples thereof include polyamide resins, epoxy resins, phenol resins, melamine resins, ultraviolet curable resins, natural product-derived polymers, heat-modified silicone polymers, and thermoplastic elastomers.

  Therefore, the resin component of the porous resin bead of the present invention is a plurality of monomers having a copolymerizable functional group selected from those having a copolymerizable functional group for forming the resin listed above. Any copolymer component may be used as long as they are combined and polymerized. As a more preferable monomer (monomer) having a copolymerizable functional group used in the present invention, a polyfunctional monomer having a plurality of copolymerizable functional groups in its structure as described later is used. And crosslinkable monomers. Further, according to the study by the present inventors, although it depends on the use, among monomers having a copolymerizable functional group, light resistance, transparency, and excellent paint suitability such as workability, It is more preferable to use a monomer that forms an acrylic resin such as a (meth) acrylate monomer. Specifically, known acrylic or methacrylic monomers can be used more preferably acrylic monomers. In the present specification, (meth) acrylate means methacrylate or acrylate.

  Further, according to the study of the present inventor, the resin component constituting the porous resin bead of the present invention as described above includes a plurality of copolymerizable functional groups in all monomers used for polymerization. It is preferable to design the monomer having 20% by mass or more, further 30% by mass or more based on mass. That is, by designing the monomer composition in this way, resin beads formed by suspension polymerization have improved suitability for color movement such as bleed resistance and migration resistance when used for paints and resins, and uniform reflection. The light reduction effect can be maintained more stably. Examples of the monomer having a plurality of copolymerizable functional groups suitably used in the present invention include copolymerizable monomers such as those listed below and cross-linkable monomers. As the copolymerizable polyfunctional monomer or cross-linking monomer, a general copolymerizable monomer containing a double bond capable of copolymerization is used. Suitable monomers for such crosslinking suitable for the present invention include, for example, ethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, butanediol diacrylate, hexanediol diacrylate. Examples thereof include bifunctional acrylates such as acrylate, nonanediol diacrylate, tricyclodecane dimethanol diacrylate, modified bisphenol A diacrylate, and bisphenol A diglycidyl ether diacrylate.

  In addition, trifunctional acrylates such as pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane ethoxytriacrylate, glycerin propoxytriacrylate,

Tetrafunctional acrylates such as pentaerythritol tetraacrylate, pentaerythritol ethoxytetraacrylate, ditrimethylolpropane tetraacrylate,
Hexafunctional acrylates such as dipentaerythritol hexaacrylate,
And (meth) acrylates such as derivatives thereof,
Oxetanes such as xylylene bisoxetane and 3-ethyl-3 [[(3-ethyloxetane-3yl) methoxy] methyl] oxetane, as well as urethane diacrylate, urethane triacrylate, polyester diacrylate, polyester triacrylate, etc. Examples of the acrylate modified compounds are

  The porous resin beads of the present invention are those obtained by suspension polymerization of a combination of two or more monomers having a copolymerizable functional group as described above. Among the above, the combination of modified bisphenol A diacrylate and hexanediol diacrylate is particularly preferable. Here, examples of the modified bisphenol A diacrylate include EO-modified products and PO-modified products. Specific modified products that can be used in the present invention are shown below.

  Examples of the black pigment constituting the porous resin beads of the present invention include carbon black, perylene black, azomethine azo black, aniline black, iron black, titanium black, and complex oxide black. Such a black pigment, a polymer dispersant, an organic solvent capable of dissolving the polymer dispersant, a polymerization initiator, and a monomer having a copolymerizable functional group as described above. When a polymerizable solution containing a plurality of monomer mixtures is subjected to suspension polymerization in an aqueous phase in which a dispersion stabilizer is dissolved, these black pigments exhibit good dispersibility in the formed resin beads. For this reason, the black porous resin beads of the present invention are excellent in uniform reflected light reduction effect and jetness. Further, according to the study of the present inventor, it is preferable to use a composite oxide black among the above-mentioned pigments, and in that case, it contains at least any element of Cu, Fe or Mn. Excellent jet blackness can be realized, and by using such resin beads, it is possible to provide a more excellent product in terms of uniform reflected light reduction effect and improvement in design.

  One feature of the porous resin beads of the present invention is that they contain a polymer dispersant. The presence of the polymer dispersant makes it possible to satisfactorily disperse the black pigment as mentioned above in the porous resin beads. Therefore, the porous resin beads of the present invention can be used for various applications. If so, uniform reflected light reduction effect and jetness can be improved. As the polymer dispersant used in the present invention, any known dispersant may be used as long as it is suitable for the black pigment to be used. Specific polymer dispersants that can be used in the present invention include, for example, DISPERBYK-163, DISPERBYK-170, DISPERBYK-2000 (above, manufactured by Big Chemie Japan Co., Ltd.), EFKA-1101, and EFKA as examples of commercially available products. -4310 (manufactured by Ciba Specialty Chemicals Co., Ltd.), and the like. These polymer dispersants may be used alone or in combination of two or more. Since the commercially available polymer dispersant as described above may contain an organic solvent having low solubility (to water) in the polymer dispersant itself, as described later, the porous resin beads of the present invention are used. In the selection of the organic solvent to be used in the production, it is more preferable to adjust in consideration of this and optimize the solubility in water.

  In addition, the porous resin beads of the present invention comprising the above-described constituent components are preferably fine particles having a size within a range of 20 μm or less, and more preferably fine particles within a range of 15 μm or less. When it is within the above range, the porous resin beads of the present invention can effectively exhibit characteristics as a porous resin bead, for example, light reflection reduction effect and jet blackness.

  The method for producing porous resin beads of the present invention includes a black pigment, a monomer mixture containing a plurality of monomers having a copolymerizable functional group, a polymer dispersant, and an organic solvent capable of dissolving the polymer dispersant And an oil phase polymerizable solution comprising a polymerization initiator is subjected to suspension polymerization in an aqueous phase in which a dispersion stabilizer is dissolved. The “monomer mixture” in the present invention means that two or more monomers coexist at the time of the reaction, and as described later, a plurality of monomers are not necessarily mixed in advance. It is not meant to be in a state. In the present invention, it is preferable to prepare an oil phase polymerizable solution for suspension polymerization in an aqueous phase, for example, by any of the following methods. In the first method, a dispersion in which a black pigment is dispersed in advance with a polymer dispersant is obtained, and a plurality of monomers (monomer mixture) and the polymer dispersant can be dissolved in the dispersion. A known oil-soluble polymerization initiator dissolved in an organic solvent is mixed to prepare a polymerizable solution that becomes an oil phase. In this method, when preparing the dispersion in advance, the dispersion may be prepared using at least one of monomers having a copolymerizable functional group.

  Further, in another method for producing the porous resin beads of the present invention, the above-described polymer dispersant is dissolved in an organic solvent, and the resulting dissolved material is used to convert a black pigment into the dissolved material. After preparing a dispersion containing these components, a monomer mixture and a polymerization initiator are added to the dispersion and mixed to prepare a polymerizable solution that becomes an oil phase. Then, the polymerizable solution obtained by any of the above methods is subjected to suspension polymerization in an aqueous phase in which a dispersion stabilizer is dissolved, so that the remarkable effect of the present invention is obtained. Roughened porous resin beads can be easily obtained. According to the study of the present inventors, depending on the combination of the black pigment and the monomer mixture to be used, the monomer mixture may be polymerized and cured in a relatively short time due to the catalytic action. In some cases, the black pigment to be used is first dispersed with a polymer dispersant (if necessary, an organic solvent capable of dissolving the polymer dispersant is used), and then the monomer mixture and the polymer dispersant are dissolved. It is preferable to prepare a polymerizable solution by mixing with a polymerization initiator dissolved in an organic solvent, and to perform suspension polymerization using the obtained polymerizable solution.

  The polymerization initiator used in the present invention may be any known initiator that can achieve the object of the present invention. For example, the following can be used. More specifically, in the peroxide system, lauryl peroxide, benzoyl peroxide, t-butylperoxy (2-ethylhexaate) and the like can be mentioned. In the azo compound, 2,2′-azobisisobutyrate is used. Examples include rhonitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), and 2,2′-azobisisolacric acid alkyl ester. These may be used alone or in combination of two or more.

  The organic solvent used in the polymerizable solution constituting the present invention has good compatibility between the monomer mixture constituting the polymerizable solution and the polymer dispersant, and is compatible with the polymer after suspension polymerization. Preferably it is low. The reason for this is that, according to the study of the present inventors, the porous resin beads of the present invention are formed in a porous shape due to the phase change in the polymerizable solution comprising the above components that occurs during suspension polymerization. First, if the compatibility between the organic solvent used and the polymer dispersant is poor, the combined black pigment will aggregate, and the resin beads formed by suspension polymerization in the aqueous phase will be colored and jet black. This is thought to be due to the possibility that resin beads may agglomerate and suspension polymerization in a good state may not be possible. For this reason, in the present invention, the balance of dissolution of the organic solvent and the polymer dispersant contained in the polymerizable solution is important. At least the organic solvent used in the polymerizable solution dissolves the polymer dispersant used in combination. It must be possible. Here, the solubility of the polymer dispersant in the organic solvent to be used is to visually check the dissolution state by mixing the organic solvent and the polymer dispersant in a separate container at a component ratio in the polymerizable solution. Thus, it can be easily discriminated.

  Furthermore, as the organic solvent used in the present invention, it is preferable to use an organic solvent exhibiting moderate solubility (hydrophilicity) in water for the following reasons. Specifically, it is preferable to use an organic solvent having a solubility in water of 3 to 100 parts by mass with respect to 100 parts by mass of water, and more preferably 5 to 80 parts by mass. In addition, in this specification, solubility means the solubility in 25 degreeC. As the organic solvent described in the known method for producing porous resin beads, an organic solvent having low solubility in water is used. In this case, it is necessary to remove the organic solvent in a distillation step or the like, which is economically disadvantageous. It is. In the method for producing a porous resin bead according to the present invention, preferably, an organic material having moderate solubility in water, for example, having an organic solubility of 3 to 100 parts by mass with respect to 100 parts by mass of water. It is preferable to use a solvent. By adopting such a configuration, the organic solvent can be easily removed by washing with water in the washing step after polymerization, which is economically advantageous. On the other hand, when an organic solvent having a solubility in water of less than 3 parts by mass with respect to 100 parts by mass of water is used, it is difficult to remove the organic solvent even if the washing process is repeated. If more than, the elution into the aqueous medium constituting the aqueous phase used in suspension polymerization increases, which is not only economically disadvantageous, but also when the dispersion stabilizer dissolved in the aqueous medium is precipitated, This is not preferable because suspension polymerization may not be possible.

  As the organic solvent that can be used in the present invention, any known organic solvent can be preferably used as long as it is suitable for the above-described conditions. In the present invention, examples of organic solvents that can be suitably used include the following. For example, ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, alcohols such as n-butanol, ether solvents such as ethyl cellosolve, butyl cellosolve, ethylene glycol diethyl ether, Examples include glycol ether solvents such as dipropylene glycol monomethyl ether and glycol ester solvents such as propylene glycol monomethyl ether acetate. These can be used alone or in combination of a plurality of types so that the solubility in water is 3 to 100 parts by mass with respect to 100 parts by mass of water. In some cases, the polymer dispersant itself used in the present invention may contain an organic solvent having a low solubility in water. Therefore, taking this into account, 100 parts by mass of the organic solvent to be used is used. It is preferable to adjust so that the solubility of the organic solvent with respect to 3 to 100 parts by mass. Furthermore, as described above, the organic solvent used in the present invention is required to be capable of dissolving the polymer dispersant used. In this respect, the polymer dispersant used is not polymerizable. What is necessary is just to determine the organic solvent to be used by mixing with an organic solvent by the component ratio in a solution, and confirming the solution state to the organic solvent visually.

  According to the study of the present inventor, preferable ones for use in the present invention are, for example, ketone solvents, ether solvents, glycol ether solvents and glycol ester solvents, more preferably glycol esters. Among these solvents, propylene glycol monomethyl ether acetate is particularly preferable.

  In addition, the amount of the organic solvent used in the method for producing the porous resin beads of the present invention is not particularly limited, but in order to improve the surface state of the resin beads, the monomer mixture and the polymer dispersion The amount is preferably about 50 to 300 parts by mass, and more preferably 80 to 250 parts by mass with respect to 100 parts by mass in total of the agent and the black pigment. If the amount of the organic solvent to be used is too small, the surface of the resin beads to be synthesized is likely to be smooth, and the desired sufficiently roughened surface state may not be obtained. In addition, too much is not only economically disadvantageous, but also increases the organic solvent dissolved in the aqueous medium used in suspension polymerization, there is a possibility that the dispersion stabilizer added to the aqueous phase may precipitate, in some cases This is not preferable because there is a possibility that suspension polymerization cannot be stably performed. By producing the resin beads by the above production method, the obtained resin beads are porous in which the black pigment is uniformly dispersed, and at least the particle surface is roughened. The presence or absence of a porous structure formed on at least the particle surface of the resin beads obtained by the method for producing porous resin beads of the present invention can be confirmed by a scanning electron micrograph.

  In the suspension polymerization performed by the method for producing the porous resin beads of the present invention, an aqueous medium (aqueous phase) in which a dispersion stabilizer (protective colloid) is dissolved in deionized water is prepared, and the aqueous medium thus prepared is used. In addition, the polymerizable solution having the above-described configuration is mixed with stirring, and if necessary, the suspension droplet diameter of the polymerizable solution is adjusted using an emulsifier such as a homogenizer. A homogenizer or the like can easily adjust the polymerizable solution to the suspension droplet size by changing the number of rotations and adjusting the shearing force.

  Suspension droplets created by an emulsifying device such as a homogenizer are used for dispersion stabilizers to prevent problems such as droplet breakage and coalescence during droplet adjustment, transfer to the polymerization device, and polymerization process. It is preferable to set the type and concentration. Examples of the dispersion stabilizer suitably used in the present invention include water-soluble polymers such as methylcellulose, polyvinyl alcohol, and sodium acrylate, and inorganic salts such as hydroxyapatite, tricalcium phosphate, and calcium carbonate. These may be used alone or in combination of two or more.

  The suspension obtained as described above is a porous resin bead containing a black pigment dispersed in a good state by performing suspension polymerization by heating at a temperature of 60 to 80 ° C. for 3 to 10 hours. Is obtained. Further, after removing the dispersion stabilizer and the organic solvent in the washing step, disperse in deionized water, remove the dissolved matter again in the washing step, repeat the washing if necessary, and then dry. . The particles obtained in the aggregated state are crushed to obtain powdery porous resin beads.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated still in detail, this invention is not limited by these Examples. In the text, “part” or “%” is based on mass.

  In Examples and Comparative Examples, unless otherwise specified, the following partially saponified polyvinyl alcohol is used as a dispersion stabilizer constituting the aqueous phase of suspension polymerization, and the following azo compound is used as a polymerization initiator. It was. Specifically, a partially saponified polyvinyl alcohol (hereinafter abbreviated as PVA) is used as the dispersion stabilizer, and Poval 205 manufactured by Kuraray Co., Ltd. is used as the polymerization initiator, and 2,2′-azo is used as the polymerization initiator. Bisisobutyronitrile (hereinafter abbreviated as AIBN) was used, specifically, AIBN manufactured by Otsuka Chemical Co., Ltd. was used.

<Example 1>
First, 80 parts of carbon black (manufactured by Degussa, trade name: FW200), 125 parts of polymer dispersant (trade name: DISPERBYK-163), and modified bisphenol diacrylate (structured below) 150 parts of Daicel Ornex Co., Ltd., trade name: EB150) were premixed and then dispersed with a roll mill to obtain a dispersion. Then, 178 parts of the obtained dispersion, 56 parts of hexanediol diacrylate (HDDA) (manufactured by Daicel Cytec Co., Ltd.), and 1.3 parts of AIBN in advance are added to 300 parts of propylene glycol monomethyl ether acetate. The dissolved solution was added, and these were uniformly stirred and mixed to prepare a polymerizable monomer solution. The propylene glycol monomethyl ether acetate used is soluble in the polymer dispersant. The component ratio in the polymerizable solution prepared in this example is the ratio between the organic solvent and the polymer dispersant. After mixing, the dissolved state was visually confirmed.

  Next, the polymerizable solution obtained above is mixed in another container in an aqueous phase in which 80 parts of PVA as a dispersion stabilizer is dissolved in 1600 parts of ion-exchanged water, and stirred at 2500 rpm for 5 minutes in a dissolver. Further, the mixture was stirred at 8000 rpm for 5 minutes using a homogenizer to obtain a uniform suspension.

  Next, the suspension was charged into a reactor of a polymerization apparatus equipped with a stirrer and a nitrogen gas introduction tube, and a polymerization reaction was carried out at 70 ° C. for 6 hours. After cooling, the resin fine particles produced from this suspension were filtered and washed. After the resin beads thus obtained are reconstituted in ion-exchanged water, the fine particles are filtered and washed from the suspension, dried, and crushed to obtain black particles containing carbon black as a black pigment. Resin beads were obtained. As a result of observing the obtained resin beads with a scanning electron micrograph, it was confirmed that the black pigment was uniformly dispersed and a porous structure was formed on the surface of the resin particles.

<Example 2>
First, 150 parts of a complex oxide black containing elements of Cu, Fe, and Mn (manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Dipiroxide 3550), and a polymer dispersant (Bic Chemie Japan Co., Ltd.) (Product name: DISPERBYK-170) was premixed and then dispersed by a roll mill to obtain a dispersion. And 80 parts of the obtained dispersion, 74 parts of modified bisphenol diacrylate (manufactured by Daicel Ornex Co., Ltd., trade name: EB150) and hexanediol diacrylate (HDDA) (manufactured by Daicel Ornex Co., Ltd.) ) And a solution prepared by previously dissolving 1.5 parts of AIBN in 270 parts of methyl ethyl ketone, and stirring and mixing them uniformly to prepare a polymerizable monomer solution. Regarding the fact that the used methyl ethyl ketone is soluble in the above polymer dispersant, this organic solvent and polymer dispersant are mixed and dissolved at the component ratio in the polymerizable solution prepared in this example. The state was confirmed visually.

  Next, in the same manner as in Example 1 except that 1400 parts of ion-exchanged water and 70 parts of PVA as a dispersion stabilizer were dissolved in another container, the above complex oxide black was used as a black pigment. A black resin bead was obtained. As a result of observing the obtained resin beads with a scanning electron micrograph, it was confirmed that the black pigment was uniformly dispersed and a porous structure was formed on the surface of the resin particles.

<Example 3>
First, 150 parts of a complex oxide black containing elements of Cu, Fe and Mn (manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Dipyroxide 3552) and a polymer dispersant (Bic Chemie Japan Co., Ltd.) (Product name: DISPERBYK-170) 150 parts of propylene glycol monomethyl ether acetate dissolved in 150 parts of the mixture were premixed and then dispersed in a bead mill to obtain a dispersion. And 120 parts of the obtained dispersion, 74 parts of modified bisphenol diacrylate (manufactured by Daicel Ornex Co., Ltd., trade name: EB150) and hexanediol diacrylate (HDDA) (manufactured by Daicel Ornex Co., Ltd.) ) And a solution prepared by previously dissolving 1.5 parts of AIBN in 200 parts of propylene glycol monomethyl ether acetate were added, and these were uniformly stirred and mixed to prepare a polymerizable monomer solution. The propylene glycol monomethyl ether acetate used is soluble in the polymer dispersant. The component ratio in the polymerizable solution prepared in this example is the ratio between the organic solvent and the polymer dispersant. After mixing, the dissolved state was visually confirmed.

  Next, the same operation as in Example 1 was performed except that a water phase in which 70 parts of PVA was dissolved as a dispersion stabilizer was used in 1400 parts of ion-exchanged water in another container, and the composite oxide black was used as a black pigment. Black resin beads contained were obtained. As a result of observing the obtained resin beads with a scanning electron micrograph, it was confirmed that the black pigment was uniformly dispersed and a porous structure was formed on the surface of the resin particles.

<Comparative Example 1> (Example when the polymerizable monomer liquid does not contain an organic solvent)
First, 80 parts of carbon black similar to that used in Example 1 (manufactured by Degussa, trade name: FW200), 125 parts of a polymer dispersant (trade name: DISPERBYK-163, manufactured by Big Chemie Japan Co., Ltd.), and 150 parts of modified bisphenol diacrylate (manufactured by Daicel Ornex Co., Ltd., trade name: EB150) was premixed and then dispersed by a roll mill to obtain a dispersion. Then, to 178 parts of the obtained dispersion, a solution prepared by previously dissolving 1.3 parts of AIBN in 56 parts of hexanediol diacrylate (HDDA) (manufactured by Daicel Ornex Co., Ltd.) was added and stirred and mixed uniformly. A polymerizable monomer solution was prepared.

  Next, in a separate container, the above polymerizable solution is mixed in 700 parts of ion-exchanged water and an aqueous phase in which 35 parts of PVA as a dispersion stabilizer is dissolved, and stirred for 5 minutes at 2500 rpm with a dissolver. Further, a homogenizer Was stirred at 10,000 rpm for 5 minutes to obtain a uniform suspension.

  Next, the same operation as in Example 1 was performed to obtain resin beads containing carbon black as a black pigment, but the surface of the resin beads was smooth and porous resin beads were not obtained.

<Comparative Example 2> (Example in the case where the organic solvent cannot dissolve the polymer dispersant)
First, 150 parts of a composite oxide black containing the same elements of Cu, Fe, and Mn as used in Example 2 (trade name: dipyroxide 3550, manufactured by Dainichi Seika Kogyo Co., Ltd.) and polymer dispersion 150 parts of an agent (BIC Chemie Japan Co., Ltd., trade name: DISPERBYK-170) was premixed and then dispersed with a roll mill to obtain a dispersion. And 80 parts of the obtained dispersion, 74 parts of modified bisphenol diacrylate (manufactured by Daicel Ornex Co., Ltd., trade name: EB150), 270 parts of n-hexane, and AIBN1.5 A solution prepared by dissolving 74 parts of hexanediol diacrylate (HDDA) (manufactured by Daicel Cytec Co., Ltd.) in a part was stirred and mixed uniformly to prepare a polymerizable monomer solution. However, even when the obtained reaction product was filtered and washed, n-hexane could not be removed, and porous resin beads containing a black pigment could not be obtained. In addition, when the solubility with respect to the said polymer dispersing agent about the used n-hexane was confirmed by mixing with the component ratio in the polymeric solution prepared by this comparative example, sufficient solubility was not shown.

<Evaluation>
(Volume average particle diameter)
The volume average particle diameter of each resin bead prepared in each of Examples 1 to 3 and Comparative Example 1 was measured with a Coulter Counter (manufactured by Beckman Coulter, Inc.). The obtained results are summarized in Table 1.

(Reflected light reduction effect)
The reflected light reduction effect of each resin bead prepared in each of Examples 1 to 3 and Comparative Example 1 was measured and evaluated as follows. Each of the resin beads prepared in Examples 1 to 3 and Comparative Example 1 was used for each, and each acrylic paint prepared so that the resin bead concentration in the coating film was 20% was applied to the same substrate with an applicator. Then, a coating film was formed. And about each formed coating film, 60 degree reflected light was measured with the gloss meter (Suga Test Instruments Co., Ltd. make, brand name: HG-268). The results are summarized in Table 1.

(Blackness)
The jetness of each resin bead prepared in each of Examples 1 to 3 and Comparative Example 1 was evaluated as follows. Each of the resin beads prepared in Examples 1 to 3 and Comparative Example 1 was used for each, and each acrylic paint prepared so that the resin bead concentration in the coating film was 20% was applied to the same substrate with an applicator. Then, a coating film was formed. And about each formed coating film, the jet-black uniformity was observed visually. The results are summarized in Table 1.

(Evaluation results)
When the porous resin beads containing the black pigments of Examples 1 to 3 are used for the paint and the case where the resin beads of Comparative Example 1 are used for the paint, the coating films formed using these paints In comparison, as shown in Table 1, particularly when the porous resin beads containing the black pigments of Examples 1 to 3 are used in the paint, the reflected light is sufficiently reduced and the gloss is suppressed. Furthermore, it showed a jet black feeling with a high design. As a result, by using the porous resin beads containing the black pigments of Examples 1 to 3, it is possible to obtain a molded body, a film, a coating agent, and a resin composition that show a jet black feeling with high design properties.

  By using the porous resin beads containing the black pigment of the present invention in, for example, a paint, the reflected light of the coating film can be sufficiently reduced, and a product that achieves a jet black feeling with high design can be obtained. . Therefore, the black porous resin beads of the present invention are most suitable for use in fields requiring such characteristics and functions, such as molded articles, films, coating agents, and resin compositions, and are used in various applications. There is expected.

Claims (14)

  A state in which a monomer mixture containing a plurality of monomers having a copolymerizable functional group is present in at least a black pigment, a polymer dispersant, and an organic solvent capable of dissolving the polymer dispersant A porous resin particle obtained by suspension polymerization in which a black pigment is contained in the porous resin particle and at least the surface thereof is roughened. Resin beads.   The porous resin bead according to claim 1, wherein the monomer having a copolymerizable functional group is a (meth) acrylate-based monomer.   The porous resin bead according to claim 1 or 2, wherein the monomer mixture contains at least 20% by mass of a monomer having a plurality of copolymerizable functional groups on a mass basis.   4. The black pigment according to any one of claims 1 to 3, wherein the black pigment is selected from the group consisting of carbon black, perylene black, azomethine azo black, aniline black, iron black, titanium black, and complex oxide black. Porous resin beads.   The porous resin bead according to claim 4, wherein the complex oxide-based black contains at least one element selected from the group consisting of Cu, Fe, and Mn.   The porosity according to any one of claims 1 to 5, wherein the monomer mixture contains a modified bisphenol diacrylate and hexanediol diacrylate, which are monomers having a plurality of copolymerizable functional groups. Quality resin beads.   The porous resin beads according to any one of claims 1 to 6, wherein a volume average particle diameter of the porous resin particles is 20 µm or less.   A polymerizable solution containing a black pigment, a monomer mixture containing a plurality of monomers having a copolymerizable functional group, a polymer dispersant, an organic solvent capable of dissolving the polymer dispersant, and a polymerization initiator, A method for producing black porous resin beads, characterized in that black porous resin particles having at least a roughened particle surface are produced by suspension polymerization in an aqueous phase in which a dispersion stabilizer is dissolved.   The porous resin beads according to claim 8, wherein, when the polymerizable solution is prepared, the polymer dispersant is dissolved in the organic solvent, and the polymerizable solution is prepared using the obtained solution. Production method.   When preparing the polymerizable solution, a dispersion is prepared in advance using at least one of the black pigment, the polymer dispersant, and, if necessary, the monomer having a copolymerizable functional group. The method for producing porous resin beads according to claim 8 or 9, wherein a polymerizable solution is prepared using the obtained dispersion.   The said organic solvent shows the solubility with respect to water whose solubility in water is 3-100 mass parts with respect to 100 mass parts of water, The any one of Claims 8-10. Manufacturing method of porous resin beads.   The porous material according to any one of claims 8 to 11, wherein the organic solvent is at least one selected from the group consisting of a ketone solvent, an ether solvent, a glycol ether solvent, and a glycol ester solvent. For producing high-quality resin beads.   The method for producing porous resin beads according to any one of claims 8 to 12, wherein the organic solvent is propylene glycol monomethyl ether acetate.   It is a product of any one of a molded article, a film, a coating agent, a paint, a pigment dispersion, or a resin composition, and includes the porous resin beads according to any one of claims 1 to 7. A product with a low-gloss texture.