JP6410266B2 - Method for producing polymer particles - Google Patents

Description

  The present invention relates to polymer particles suitably used as a raw material for optical members such as a light diffusion film and an antiglare film, uses of the polymer particles (optical film and resin molded product), and a method for producing the polymer particles About.

  Polymer particles having a volume average particle diameter of 1 to 100 μm are, for example, additives for coating agents such as paints (matting agents etc.), additives for inks (matting agents etc.), main components of adhesives or Additives, artificial marble additives (low shrinkage agents, etc.), paper treatment agents, packing materials for external preparations such as cosmetics (fillers for improving slipperiness), column packing materials used for chromatography, electrostatic charge Used in applications such as toner additives used for image development, anti-blocking agents for films, and light diffusing agents for optical members (optical films such as light diffusing films and antiglare films, light diffusers, etc.) ing.

  Such polymer particles can be produced by polymerizing a polymerizable monomer. Known polymerization methods for polymerizing polymerizable monomers include suspension polymerization, seed polymerization, and emulsion polymerization. In these polymerization methods, a surfactant is usually used so that the polymerization reaction is stably performed and the generation of coarse particles is suppressed.

  For example, Patent Document 1 discloses that resin fine particles (polymer particles) used as a light diffusing agent are obtained by polymerizing a vinyl monomer in a medium containing a surfactant and remain in the resin fine particles. The amount of the surfactant is 0.05 parts by weight or less (specifically, 0.005 to 0.36 parts by weight) with respect to 100 parts by weight of the resin fine particles.

  Patent Document 2 discloses washing organic particles (polymer particles) having a surface-active agent obtained by emulsion polymerization or suspension polymerization as organic particles blended in an epoxy resin composition. What has been processed is disclosed.

JP 2006-233055 A JP 2007-016183 A

  By the way, as optical films, such as a light-diffusion film and an anti-glare film, there exist some which apply a resin composition containing a polymer particle and a binder on a film base material.

  In the case of producing such an optical film, before coating the resin composition on the film substrate so that stable optical characteristics can be obtained by the coating film comprising the resin composition on the film substrate. In addition, it is necessary to uniformly disperse the polymer particles in the resin composition (specifically, in the binder).

  However, even if the polymer particles produced using the surfactants disclosed in Patent Documents 1 and 2 are uniformly dispersed in a binder to obtain a resin composition, the resin composition is still on the film substrate. In the process of forming a coating film by coating the polymer particles, the dispersion state of the polymer particles in the resin composition becomes unstable. For example, when producing the optical film using the polymer particles disclosed in Patent Documents 1 and 2, in the process of forming a coating film by the coating, the polymer particles in the resin composition are formed. The dispersion state was not stable, and the polymer particles sometimes aggregated excessively. As a result, polymer particles may not spread over the entire coating film formed on the base film, and desired optical characteristics may not be stably obtained.

  Therefore, in the process of forming a coating film by coating a resin composition obtained by dispersing polymer particles in a binder onto the above film substrate, a stable dispersion state is obtained, and the optical film is stably optical. There has been a demand for development of polymer particles excellent in dispersion stability capable of imparting characteristics.

  The present invention has been made in view of the above situation, and an object thereof is to provide polymer particles excellent in dispersion stability, a method for producing the same, and an optical film and a resin molded body using the polymer particles. To do.

  As a result of intensive studies in view of the above problems, the inventors of the present application have found that the surface state of the polymer particles has an influence on the dispersion stability, and the improvement of the dispersion stability involves a production process in the polymer particles. It was found that the content (residual amount) of the surfactant used in 1) needs to be suppressed very slightly (specifically, less than 50 ppm).

  The polymer particles of the present invention are characterized in that the surfactant content is more than 0 ppm and less than 50 ppm.

  Since the polymer particles of the present invention have a surfactant content of less than 50 ppm, they are excellent in dispersion stability in the binder when used in combination with a binder. Further, when a resin composition obtained by dispersing the polymer particles of the present invention in a binder is applied on a film substrate, the dispersion state of the polymer particles in the resin composition is determined by the coating method. Thus, it is maintained almost stably in the process of forming the coating film, and excessive aggregation of the polymer particles during the coating is suppressed. As a result, the polymer particles spread evenly on the film substrate, and can impart optical characteristics such as stable light diffusibility and antiglare property to the entire coating film formed by the coating.

  The optical film of the present invention is characterized by coating a coating resin composition containing the polymer particles of the present invention and a binder on a film substrate.

  Since the optical film of the present invention is formed by coating a substrate with the coating resin composition containing the polymer particles of the present invention having excellent dispersion stability, the entire coating film formed by the coating , Stable optical properties such as light diffusibility and antiglare properties can be obtained. Therefore, according to the optical film of the present invention, high quality stability can be obtained.

  The resin molded body of the present invention is characterized by molding a molding resin composition containing the polymer particles of the present invention and a transparent resin.

  Since the resin molded body of the present invention is formed by molding a molding resin composition containing the polymer particles of the present invention having excellent dispersion stability, in the resin molded body, there is no uneven light diffusibility or Optical properties such as antiglare properties can be obtained stably. Therefore, according to the resin molding of the present invention, high quality stability can be obtained.

In the method for producing polymer particles of the present invention, a vinyl monomer is polymerized in a liquid medium in the presence of a surfactant, and the polymer particle containing the surfactant and the medium are mixed. A polymerization step for obtaining a product, and the crude product is charged into a filter, and the medium contained in the charged crude product is passed through the filter medium of the filter while the polymer particles contained in the crude product. A solid-liquid separation step for holding the polymer particles on the filter medium, and a cleaning liquid is charged into the filter that holds the polymer particles on the filter medium, the cleaning liquid is brought into contact with the polymer particles, and the polymer particles and A unit of passing the filter medium in the solid-liquid separation step by passing the cleaning liquid in contact with the filter medium to obtain polymer particles washed with the cleaning liquid on the filter medium. The amount per hour is Equation (1);
X ≦ 5.50 × A (1)
(In Formula (1), X means the amount (kg / min) per unit time of the medium that has passed through the filter medium, and A represents the area (m ² ) of the interface between the filter medium and the object to be filtered). The amount of the cleaning liquid per unit time that has passed through the filter medium in the cleaning step is the following conditional expression (2):
Y ≦ 8.50 × A (2)
(In Formula (2), Y means the amount (kg / min) per unit time of the cleaning liquid that has passed through the filter medium, and A represents the area (m ² ) of the interface between the filter medium and the object to be filtered). In the washing step, a washing liquid having a weight 10 times or more of the weight of the polymer particles held on the filter medium is used.

  In the above production method, the amount per unit time of the medium that has passed through the filter medium satisfies the conditional expression (1) in the solid-liquid separation step, and the amount per unit time of the cleaning liquid that has passed through the filter medium in the washing process is the conditional expression ( 2), and in the washing step, a washing liquid having a weight of 10 times or more the weight of the polymer particles held on the filter medium is used. Therefore, the surfactant adhering to the polymer particles in the polymerization step is used. Most can be removed along with the media and cleaning solution. As a result, it is possible to obtain polymer particles excellent in dispersion stability with a very small surfactant content (residual amount).

  ADVANTAGE OF THE INVENTION According to this invention, the polymer film excellent in dispersion stability, its manufacturing method, the optical film using the polymer particle, and a resin molding can be provided.

FIG. 1 is a schematic diagram showing a schematic configuration of a pressure filter usable in an embodiment of the present invention, (a) is a schematic cross-sectional view of the pressure filter, and (b) is the pressure filter. It is a schematic top view which shows the inside of the pressure vessel of a pressure filter.

  The present invention is described in detail below.

(Polymer particles)
The polymer particles of the present invention are characterized in that the surfactant content is more than 0 ppm and less than 50 ppm. In the polymer particles of the present invention, the content of the surfactant is preferably as small as possible, preferably from 0 ppm to 30 ppm, more preferably from 0 ppm to 20 ppm, more preferably from 0 ppm to 15 ppm. Is more preferable. The content of the surfactant in the polymer particles can be measured using, for example, liquid chromatography mass spectrometry (LC-MS-MS).

  The surfactant contained in the polymer particles of the present invention is the surfactant remaining in the production of the polymer particles. For this reason, as the surfactant, any surfactant usually used in the production of polymer particles, for example, an anionic surfactant as described in the section of [Method for producing polymer particles] described later, Nonionic surfactants, cationic surfactants, and amphoteric surfactants can be exemplified. Moreover, it is preferable that the surfactant contained in the polymer particles of the present invention contains at least one of an anionic surfactant and a nonionic surfactant.

  In the polymer particles, the fact that the surfactant is included, that is, the content of the surfactant exceeds 0 ppm, for example, is measured in a time-of-flight secondary ion mass spectrometer (TOF-SIMS). In the measurement of the content of the surfactant in the polymer particles using the liquid chromatograph mass spectrometer (LC / MS / MS apparatus) described later, by detecting the peak of the fragment derived from the agent, It can be confirmed by detecting a peak on the chromatogram.

  The polymer particles of the present invention are those in which the content (residual amount) of the surfactant used in the production is suppressed to less than 50 ppm, so it can be said that the amount of the surfactant on the particle surface is small. For this reason, when the polymer particles of the present invention are used by mixing with a binder, there is little difference in the surface state between the polymer particles mixed with the binder, and as a result, the polymer particles of the present invention are dispersed. When used by being dispersed in a medium, the dispersion state of the polymer particles in the dispersion medium is maintained almost stably. That is, the polymer particles of the present invention are excellent in dispersion stability. The polymer particles of the present invention are those in which the content (residual amount) of the surfactant used in the production is suppressed to less than 50 ppm, and the amount of the surfactant on the particle surface is small. Therefore, when the polymer particles of the present invention are used in a mixture with a dispersion medium, the time required for uniform dispersion in the dispersion medium is stable. Further, as described above, the polymer particles of the present invention are obtained by dispersing polymer particles in a binder, for example, because the amount of the surfactant on the particle surface is small and the dispersion stability is excellent. When the resin composition is used on a film substrate, the dispersion state of the polymer particles in the resin composition is maintained almost stably in the process of forming a coating film by the coating. In addition, excessive aggregation of the polymer particles during the coating can be suppressed. As a result, the polymer particles spread evenly on the film substrate, and can impart optical characteristics such as stable light diffusibility and antiglare property to the entire coating film formed by the coating. For this reason, the optical film produced using the polymer particles of the present invention has excellent quality stability.

In the polymer particles of the present invention, the content of the surfactant on the particle surface is preferably as small as possible. For example, the total ionic strength and negative ions of positive ions measured by a time-of-flight secondary ion mass spectrometer are used. The ratio of the ionic strength of negative ions derived from the surfactant to the total of the total ionic strength (hereinafter referred to as ionic strength ratio) is 0.01 × 10 ^{−4 to} 2.0 × 10 ^−4. Is preferred. In the measurement with a time-of-flight secondary ion mass spectrometer, when a plurality of negative ion fragment peaks derived from the surfactant are detected, the ionic strength is the highest among the detected fragments. The ionic strength ratio is obtained by taking the ionic strength of a high fragment as the ionic strength of negative ions derived from the surfactant.

  From the ionic strength ratio, it is recognized that the polymer particles having the ionic strength ratio within the above range have a very small amount of the surfactant on the particle surface. For this reason, when polymer particles having an ionic strength ratio within the above range are used by being mixed with a binder, the surface states of the polymer particles mixed with the binder are almost the same. When the coalesced particles are used by being dispersed in a dispersion medium, the dispersion state of the polymer particles in the dispersion medium is maintained extremely stably. That is, polymer particles having an ionic strength ratio within the above range are extremely excellent in dispersion stability. Further, the polymer particles having an ionic strength ratio within the above range are those in which the amount of the surfactant on the particle surface is extremely small, so that the polymer particles of the present invention are used by mixing with a dispersion medium. In some cases, the time required to uniformly disperse in the dispersion medium is more stable. In addition, when a resin composition obtained by dispersing polymer particles having an ionic strength ratio within the above range in a binder is used on a film substrate, the polymer in the resin composition is used. The dispersed state of the particles is maintained extremely stably in the process of forming the coating film by the coating, and excessive aggregation of the polymer particles during the coating is surely suppressed. As a result, the polymer particles spread more uniformly on the film substrate and can reliably impart optical properties such as stable light diffusibility and antiglare properties to the entire coating film formed by the coating. . For this reason, the optical film produced using the polymer particles having an ionic strength ratio within the above range is excellent in quality stability.

  The polymer constituting the polymer particles of the present invention is, for example, a vinyl monomer polymer. Examples of the vinyl monomer include a monofunctional vinyl monomer having one ethylenically unsaturated group and a polyfunctional vinyl monomer having two or more ethylenically unsaturated groups. .

  Examples of the monofunctional vinyl monomer include, for example, (meth) acrylate monomers; styrene monomers (aromatic vinyl monomers); vinyl acetate, vinyl propionate, vinyl versatate, etc. Saturated fatty acid vinyl monomers; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; ethylenic unsaturation such as acrylic acid, methacrylic acid, crotonic acid, citraconic acid, itaconic acid, maleic acid and fumaric acid Carboxylic acid; Ethylenically unsaturated carboxylic acid anhydride such as maleic anhydride; Ethylenically unsaturated dicarboxylic acid monoalkyl ester such as monobutylmaleic acid; Ethylenically unsaturated carboxylic acid and ethylenically unsaturated dicarboxylic acid monoalkyl ester Ethylenically unsaturated carboxylates such as ammonium salts or alkali metal salts thereof; acrylic Ethylenically unsaturated carboxylic acid amides such as amide, methacrylamide and diacetone acrylamide; N-methylol acrylamide, N-methylol methacrylamide, methylolated diacetone acrylamide, and these monomers and alcohols having 1 to 8 carbon atoms And methylolates of ethylenically unsaturated carboxylic acid amides such as etherified products (eg, N-isobutoxymethylacrylamide) and derivatives thereof.

  Examples of the (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isononyl acrylate, and acrylic acid. Alkyl acrylate monomers such as lauryl and stearyl acrylate; alkyl methacrylate monomers such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate and stearyl methacrylate; glycidyl acrylate (Meth) acrylic acid ester having an epoxy group (glycidyl group) such as glycidyl methacrylate; hydroxyalkyl (meth) acrylate such as 2-hydroxyethyl methacrylate and 2-hydroxypropyl acrylate; Bruno methacrylate, having an amino group such as diethylaminoethyl methacrylate (meth) acrylic acid ester. The (meth) acrylic acid ester monomer preferably contains at least one of an alkyl acrylate monomer and an alkyl methacrylate monomer. In this application document, “(meth) acrylate” means acrylate or methacrylate, and “(meth) acryl” means acryl or methacryl.

  Examples of the styrenic monomer include styrene, α-methylstyrene, vinyl toluene, and ethyl vinyl benzene.

  Examples of the polyfunctional vinyl monomer include allyl (meth) acrylate, divinylbenzene, diallyl phthalate, triallyl cyanurate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di ( Examples include meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate.

  The above-mentioned vinyl monomers may be used alone or in combination of two or more.

  The polymer constituting the polymer particles is preferably any of a (meth) acrylic polymer, a styrene polymer, and a (meth) acryl-styrene polymer. Thereby, a polymer particle with high light transmittance is realizable. The (meth) acrylic polymer is a polymer of a (meth) acrylic acid ester monomer, or a (meth) acrylic acid ester monomer, a (meth) acrylic acid ester monomer, and styrene. It is a copolymer with a vinyl monomer other than the monomer. The styrene polymer is a polymer of a styrene monomer or a copolymer of a styrene monomer and a vinyl monomer other than a (meth) acrylate monomer and a styrene monomer. It is a polymer. The (meth) acrylic-styrene copolymer is a copolymer of a (meth) acrylic acid ester monomer and a styrene monomer, or a (meth) acrylic acid ester monomer. A copolymer of a styrene monomer and a vinyl monomer other than the (meth) acrylic acid ester monomer and the styrene monomer.

  The polymer constituting the polymer particles is preferably a copolymer (crosslinked polymer) of the monofunctional vinyl monomer and the polyfunctional vinyl monomer. For example, the amount of the structural unit derived from the polyfunctional vinyl monomer in the polymer is preferably in the range of 5 to 50% by weight with respect to 100% by weight of the polymer. When the quantity of the structural unit derived from the said polyfunctional vinyl-type monomer is less than the said range, the crosslinking degree of the said polymer will become low. As a result, when polymer particles are mixed with a binder and applied as a resin composition, the polymer particles may swell and increase the viscosity of the resin composition, which may reduce the coating workability. Furthermore, as a result of the low degree of crosslinking of the polymer, the polymer particles are mixed with the binder and molded when the polymer particles are heated during mixing or molding (so-called kneading application). Particles are easily dissolved or deformed. When the amount of the structural unit derived from the polyfunctional vinyl monomer is larger than the above range, the improvement in the effect commensurate with the use amount of the polyfunctional vinyl monomer is not recognized, and the production cost increases. There is.

  The gel fraction of the polymer particles of the present invention is preferably 90% or more, and more preferably 97% or more. If the gel fraction is less than 90%, sufficient solvent resistance cannot be ensured. For example, polymer particles are mixed with an organic solvent together with a binder and coated on a film substrate to produce an antiglare film or light. In the case of an optical film such as a diffusion film, polymer particles are dissolved in an organic solvent, and there is a possibility that optical properties such as light diffusibility and antiglare property cannot be obtained sufficiently. In addition, in this application document, a gel fraction shall point out the gel fraction measured, for example by the method as described in the term of an Example.

  The volume average particle diameter of the polymer particles is preferably 0.5 to 100 μm, and more preferably 1 to 30 μm. Thereby, when polymer particles are used for an optical member such as an antiglare film or a light diffusing film, optical properties such as antiglare property and light diffusibility of the optical member can be improved. In the present application document, the volume average particle diameter of the polymer particles refers to the arithmetic average of the volume-based particle size distribution measured by the Coulter method, for example, the method described in the Examples section.

  The coefficient of variation (CV) of the particle diameter of the polymer particles is preferably 15% or less. Thereby, when polymer particles are used for an optical member such as an antiglare film or a light diffusing film, optical properties such as antiglare property and light diffusibility of the optical member can be improved.

  The polymer particles are preferably obtained by polymerizing (ie, seed polymerizing) a vinyl monomer by absorbing the vinyl monomer in the presence of a surfactant. Since polymer particles obtained by seed polymerization have little variation in particle diameter, when used in an optical member such as an antiglare film or a light diffusing film, the antiglare property and light diffusibility of the optical member, etc. It is possible to improve the optical characteristics.

[Production method of polymer particles]
The polymer particles of the present invention can be produced by the production method of the present invention.

  In the method for producing polymer particles of the present invention, a vinyl monomer is polymerized in a liquid medium in the presence of a surfactant, and the polymer particle containing the surfactant and the medium are mixed. A polymerization step for obtaining a product, and the crude product is charged into a filter, and the medium contained in the charged crude product is passed through the filter medium of the filter while the polymer particles contained in the crude product. A solid-liquid separation step for holding the polymer particles on the filter medium, and a cleaning liquid is charged into the filter that holds the polymer particles on the filter medium, the cleaning liquid is brought into contact with the polymer particles, and the polymer particles and A cleaning step of passing the contacted cleaning liquid through the filter medium to obtain polymer particles cleaned with the cleaning liquid on the filter medium.

  Hereinafter, each process of the manufacturing method of this invention is explained in full detail.

[Polymerization process]
In the polymerization step, a vinyl monomer is polymerized in a liquid medium in the presence of a surfactant to obtain a crude product containing the polymer particles containing the surfactant and the medium.

  The liquid medium (medium contained in the crude product) is preferably an aqueous medium, for example, water; lower alcohols such as methyl alcohol and ethyl alcohol (alcohols having 5 or less carbon atoms); mixtures of water and lower alcohols, etc. Is mentioned.

  In the polymerization step, the surfactant stabilizes the dispersion of the vinyl monomer in the liquid medium. As the surfactant, any of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant can be used. In the polymerization step, a liquid medium is used. The dispersion of the vinyl-based monomer can be more stably ensured, and polymer particles having a uniform particle diameter can be obtained, so that at least one of an anionic surfactant and a nonionic surfactant Is preferably used.

  As the anionic surfactant, any known anionic surfactant such as fatty acid salt type, sulfate ester type, sulfonate type and the like can be used. For example, sodium oleate, castor oil potash soap, etc. Fatty acid soaps; alkyl sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate; alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate; alkyl naphthalene sulfonates, alkane sulfonates, di (2-ethylhexyl) sulfosuccinate (sodium) Salt), dialkylsulfosuccinates such as dioctylsulfosuccinate (sodium salt); alkenyl succinate (dipotassium salt); alkyl phosphate ester salt; naphthalene sulfonate formalin condensate; polyoxyethylene alkylphenyl ester Ether sulfates, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether sulfate such as sodium sulfate; polyoxyethylene alkyl sulfates, polyoxyethylene styrenated phenyl ether sulfuric acid ester salts. These anionic surfactants may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the nonionic surfactant, any known nonionic surfactant such as an ester type, an ether type, and an ester / ether type can be used. For example, a polyoxyethylene alkyl such as polyoxyethylene tridecyl ether can be used. Ether, polyoxyethylene alkylphenyl ether such as polyoxyethylene octylphenyl ether, polyoxyethylene styrenated phenyl ether, polyoxyalkylene alkyl ether such as polyoxyalkylene tridecyl ether having 3 or more carbon atoms in the alkylene group, poly Oxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester such as polyoxyethylene sorbitan monolaurate, polyoxyethylene alkylamine, glycerin Fatty acid esters, oxyethylene - oxypropylene block polymers and the like. These nonionic surfactants may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the cationic surfactant, known cationic surfactants such as amine salt type and quaternary ammonium salt type can be used, but water-soluble cationic surfactants are used from the viewpoint of handling. It is advantageous. Specific examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate; alkyltrimethylammonium such as lauryltrimethylammonium chloride, hexadecyltrimethylammonium chloride, cocoyltrimethylammonium chloride, and dodecyltrimethylammonium chloride. Chloride; alkyl dimethyl benzyl chlorides such as hexadecyl dimethyl benzyl ammonium chloride and lauryl dimethyl benzyl ammonium chloride; These cationic surfactants may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the amphoteric surfactants include lauryl dimethylamine oxide, phosphate ester surfactants, phosphite ester surfactants, and the like. These amphoteric surfactants may be used alone or in combination of two or more.

  The said surfactant may be used individually by 1 type, and may be used in combination of 2 or more type. The surfactant preferably has a solubility in water at a liquid temperature of 25 ° C. of 0.3 g / 100 ml to 5.0 g / 100 ml, more preferably 0.5 g / 100 ml to 3.0 g / 100 ml. If a surfactant having a solubility of less than 0.3 g / 100 ml is used, the vinyl monomer may not be stably dispersed in the aqueous medium when the liquid medium is an aqueous medium in the polymerization step. In addition, since it is difficult to elute the surfactant into water, a large amount of cleaning solution is required in the cleaning step described later for cleaning the polymer particles, which is not preferable in terms of productivity. On the other hand, a surfactant having a solubility exceeding 5.0 g / 100 ml has a poor hydrophobic group effect and a poor effect of stabilizing the dispersion of the vinyl monomer in an aqueous medium. When used, in the polymerization step, when the liquid medium is an aqueous medium, a large amount of a surfactant is required to stabilize the dispersion of the vinyl monomer in the aqueous medium. It is not preferable in terms of sex.

  The amount of the surfactant used in the polymerization of the vinyl monomer is preferably in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the vinyl monomer. When the amount of the surfactant used is less than the above range, the polymerization stability may be lowered. Moreover, when there is more usage-amount of surfactant than the said range, it is uneconomical in terms of cost.

  The polymerization method of the vinyl monomer is not particularly limited as long as it is a known polymerization method using a liquid medium and a surfactant. For example, methods such as seed polymerization, emulsion polymerization, suspension polymerization, etc. Is mentioned. Of these polymerization methods, seed polymerization is most preferred because the resulting polymer particles have the least variation in particle diameter.

  The above emulsion polymerization is a mixture of a liquid medium, a vinyl monomer that is difficult to dissolve in this medium, and a surfactant (emulsifier), and a polymerization initiator that is soluble in the medium is added thereto to perform polymerization. The polymerization method to be performed. The emulsion polymerization is characterized in that there is little variation in the particle diameter of the polymer particles obtained. The suspension polymerization is a polymerization method in which a vinyl monomer and an aqueous medium such as water are mechanically stirred to suspend the vinyl monomer in the aqueous medium for polymerization. The suspension polymerization is characterized in that polymer particles having a small particle size and a relatively uniform particle size can be obtained.

  The seed polymerization is a method in which, when starting the polymerization of the vinyl monomer, the seed (seed) particles made of a polymer of a vinyl monomer separately prepared are put into the polymerization. More specifically, in the seed polymerization, polymer particles made of a vinyl monomer polymer are used as seed particles, the vinyl particles are absorbed in the seed particles in an aqueous medium, This is a method of polymerizing a vinyl monomer. In this method, polymer particles having a larger particle diameter than the original seed particles can be obtained by growing the seed particles. As described above, since the polymerization method of the vinyl monomer is most preferably seed polymerization, in the production method of the present invention, the polymerization step is performed in a liquid medium in the presence of seed particles and a surfactant. Preferably, the method includes seed polymerizing a vinyl monomer to obtain a crude product including the polymer particles including the surfactant and the medium.

  A general method of seed polymerization will be described below, but the polymerization method in the production method of the present invention is not limited to this method.

  In seed polymerization, first, seed particles are added to an emulsion (suspension) containing a vinyl monomer, an aqueous medium, and a surfactant. The emulsion can be prepared by a known method. For example, an emulsion can be obtained by adding a vinyl monomer and a surfactant to an aqueous medium and dispersing them with a fine emulsifier such as a homogenizer, an ultrasonic processor, or a nanomizer. As the aqueous medium, water or a mixture of water and an organic solvent (for example, a lower alcohol (alcohol having 5 or less carbon atoms)) can be used.

  The amount of the surfactant used in the seed polymerization is preferably in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the vinyl monomer. When the amount of the surfactant used is less than the above range, the polymerization stability may be lowered. Moreover, when there is more usage-amount of surfactant than the said range, it is uneconomical in terms of cost.

  The seed particles may be added to the emulsion as it is, or may be added to the emulsion in a form dispersed in an aqueous medium. After the seed particles are added to the emulsion, the vinyl monomer is absorbed by the seed particles. This absorption can usually be performed by stirring the emulsion at room temperature (about 20 ° C.) for 1 to 12 hours. Moreover, in order to accelerate | stimulate absorption of the vinyl-type monomer to a seed particle, you may heat an emulsion to about 30-50 degreeC.

  The seed particles swell by absorbing the vinyl monomer. The mixing ratio of the vinyl monomer to the seed particles is preferably within the range of 5 to 300 parts by weight of the vinyl monomer and 1 to 250 parts by weight with respect to 1 part by weight of the seed particles. More preferably, it is within. When the mixing ratio of the vinyl monomer is smaller than the above range, the increase in particle diameter due to polymerization is small, and thus the production efficiency is lowered. On the other hand, when the mixing ratio of the vinyl monomer is larger than the above range, the vinyl monomer is not completely absorbed by the seed particles, and is suspension-polymerized independently in an aqueous medium, resulting in an abnormally small particle size. Polymer particles may be produced. In addition, the completion | finish of absorption of the vinyl-type monomer to a seed particle can be determined by confirming expansion of a particle diameter by observation with an optical microscope.

  Next, polymer particles are obtained by polymerizing the vinyl monomer absorbed by the seed particles. In addition, you may obtain polymer particle | grains by repeating the process of making a seed particle absorb and polymerize a vinyl-type monomer in multiple times.

  A polymerization initiator may be added to the vinyl monomer as necessary. The polymerization initiator may be obtained by mixing the polymerization initiator with the vinyl monomer, and then dispersing the obtained mixture in an aqueous medium, or combining both the polymerization initiator and the vinyl monomer. Those separately dispersed in an aqueous medium may be mixed. The particle size of the vinyl monomer droplets present in the resulting emulsion is preferably smaller than the particle size of the seed particles because the vinyl monomer is efficiently absorbed by the seed particles.

  Although it does not specifically limit as said polymerization initiator, For example, benzoyl peroxide, lauroyl peroxide, o-chloro peroxide benzoyl, o-methoxy benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide Organic peroxides such as oxide, t-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide; 2,2′-azobisisobutyronitrile, 2,2′-azobis (2, 4-dimethylvaleronitrile), 2,2′-azobis (2,3-dimethylbutyronitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,3,3) 3-trimethylbutyronitrile), 2,2′-azobis (2-isopropylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitri) ), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), (2-carbamoylazo) isobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), dimethyl-2, Examples include azo compounds such as 2′-azobisisobutyrate. The polymerization initiator is preferably used within a range of 0.1 to 1.0 part by weight with respect to 100 parts by weight of the vinyl monomer.

  The polymerization temperature of the seed polymerization can be appropriately selected according to the type of vinyl monomer and the type of polymerization initiator used as necessary. Specifically, the polymerization temperature of the seed polymerization is preferably 25 to 110 ° C, and more preferably 50 to 100 ° C. The polymerization time for the seed polymerization is preferably 1 to 12 hours. The polymerization reaction of the seed polymerization may be performed in an atmosphere of an inert gas (for example, nitrogen) that is inert to the polymerization. The seed polymerization is preferably carried out by raising the temperature after the vinyl monomer and the polymerization initiator used as necessary are completely absorbed by the seed particles.

  In the seed polymerization, a polymer dispersion stabilizer may be added to the polymerization reaction system in order to improve the dispersion stability of the polymer particles. Examples of the polymer dispersion stabilizer include polyvinyl alcohol, polycarboxylic acid, celluloses (such as hydroxyethyl cellulose and carboxymethyl cellulose), and polyvinylpyrrolidone. Moreover, the polymer dispersion stabilizer and an inorganic water-soluble polymer compound such as sodium tripolyphosphate may be used in combination. Of these polymer dispersion stabilizers, polyvinyl alcohol and polyvinyl pyrrolidone are preferred. The addition amount of the polymer dispersion stabilizer is preferably in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the vinyl monomer.

  Also, in order to suppress the generation of emulsified particles (polymer particles with too small particle size) in the aqueous medium in the above polymerization reaction, nitrites such as sodium nitrite, sulfites, hydroquinones, ascorbic acids, water-soluble Water-soluble polymerization inhibitors such as vitamin Bs, citric acid and polyphenols may be added to the aqueous medium. The addition amount of the polymerization inhibitor is preferably in the range of 0.02 to 0.2 parts by weight with respect to 100 parts by weight of the vinyl monomer.

  The polymerization method for obtaining seed particles by polymerizing a vinyl monomer is not particularly limited, but dispersion polymerization, emulsion polymerization, soap-free emulsion polymerization (emulsion polymerization without using a surfactant as an emulsifier). , Seed polymerization, suspension polymerization and the like can be used. In order to obtain polymer particles having a substantially uniform particle size by seed polymerization, it is necessary to first use seed particles having a substantially uniform particle size and grow these seed particles substantially uniformly. Seed particles having a substantially uniform particle size as a raw material can be produced by polymerizing a vinyl monomer by a polymerization method such as soap-free emulsion polymerization (emulsion polymerization without using a surfactant) and dispersion polymerization. Accordingly, emulsion polymerization, soap-free emulsion polymerization, seed polymerization, and dispersion polymerization are preferred as polymerization methods for polymerizing vinyl monomers to obtain seed particles.

  Also in the polymerization for obtaining seed particles, a polymerization initiator is used as necessary. Examples of the polymerization initiator include persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate; benzoyl peroxide, lauroyl peroxide, o-chlorobenzoyl peroxide, o-methoxybenzoyl peroxide, 3, 5 , 5-trimethylhexanoyl peroxide, tert-butylperoxy-2-ethylhexanoate, organic peroxides such as di-tert-butyl peroxide; 2,2′-azobisisobutyronitrile, Examples thereof include azo compounds such as 1′-azobiscyclohexanecarbonitrile and 2,2′-azobis (2,4-dimethylvaleronitrile). The amount of the polymerization initiator used is preferably in the range of 0.1 to 3 parts by weight with respect to 100 parts by weight of the vinyl monomer used to obtain seed particles. The weight average molecular weight of the seed particles obtained can be adjusted by adjusting the amount of the polymerization initiator used.

  In the polymerization for obtaining seed particles, a molecular weight modifier may be used in order to adjust the weight average molecular weight of the obtained seed particles. Examples of the molecular weight modifier include mercaptans such as n-octyl mercaptan and tert-dodecyl mercaptan; α-methylstyrene dimer; terpenes such as γ-terpinene and dipentene; halogenated hydrocarbons such as chloroform and carbon tetrachloride, etc. Can be used. The weight average molecular weight of the seed particles obtained can be adjusted by adjusting the amount of the molecular weight modifier used.

[Solid-liquid separation process]
In the solid-liquid separation step, the crude product is charged into a filter, and the medium contained in the charged crude product is passed through the filter medium of the filter, while the polymer particles contained in the crude product are passed through the filter. Hold on filter media.

In the solid-liquid separation step, the amount per unit time of the medium that has passed through the filter medium is the following conditional expression (1);
X ≦ 5.50 × A (1)
(In Formula (1), X means the amount (kg / min) per unit time of the medium that has passed through the filter medium, and A represents the area (m ² ) of the interface between the filter medium and the object to be filtered). Means).

  In the solid-liquid separation step, by controlling the amount of the medium that has passed through the filter medium per unit time so as to satisfy the conditional expression (1), the surfactant contained in the crude product together with the medium The amount of the surfactant remaining in the polymer particles remaining on the filter medium (specifically, the amount of the surfactant adhered on the surface of the polymer particles) can be reduced.

  In the solid-liquid separation step, the filter is not particularly limited. For example, as shown in FIG. 1, the pressure vessel 2 having a cylindrical inner space and an inner bottom portion of the pressure vessel 2 are disposed. An example of the pressure filter 1 includes a filter medium 3 and a compressed gas supply device (not shown) that supplies compressed gas (inert gas such as nitrogen, air, etc.) into the pressure vessel. In the pressure filter 1 shown in FIG. 1, the area of the bottom surface of the cylindrical inner space of the pressure vessel 2 (see FIG. 1B) is the interface between the filter medium 3 and the material to be filtered (crude product P). It is almost the same as the area.

  In the solid-liquid separation process using the pressure filter 1, for example, the crude product P is charged in the form of a slurry solution into the pressure vessel 2 of the pressure filter 1, and is placed on the filter medium 3 in the pressure vessel 2. The crude product P is filled, and the compressed gas is supplied to the upper space S of the filter medium 3 in the pressure vessel 2 by the compressed gas supply machine, whereby the upper space S of the filter medium 3 in the pressure vessel 2 is pressurized. Thereby, the crude product P is pressed against the filter medium 3, the liquid medium contained in the crude product P passes through the filter medium 3, and the liquid medium is discharged out of the pressure vessel 2 as a filtrate. Then, a cake of polymer particles remains on the filter medium 3.

  The pressure vessel 2 is preferably made of, for example, stainless steel and has a pressure resistance of 0.50 MPa or more.

  The filter medium 3 is not particularly limited as long as the polymer particles can be reliably collected. For example, a filter cloth such as a woven fabric or a nonwoven fabric made of natural fibers or synthetic fibers; a wire mesh made of sintered metal; Nonwoven fabric made of sintered metal; filter plate (perforated plate) made of natural fiber, glass fiber, etc .; net made of synthetic resin: filter paper; glass fiber filter, etc., and filter cloth is preferred.

  In the solid-liquid separation step, the pressurizing condition when pressurizing the upper space S of the filter medium 3 in the pressure resistant vessel 2 using the pressure filter 1 is a pressure satisfying the conditional expression (1). Although not particularly limited, for example, it is preferable to pressurize so that the internal pressure of the pressure resistant container 2 is within a range of 0.01 MPa to 0.50 MPa. In the solid separation step, the internal pressure of the pressure resistant vessel 2 is preferably kept almost constant so as to satisfy the conditional expression (1) from the start of pressurization to the end of the solid-liquid separation step. The internal pressure of the container 2 gradually decreases as the medium contained in the crude product P passes through the filter medium 3 after being pressurized. Specifically, when the medium passing through the filter medium 3 is reduced or almost disappeared, the compressed air pressure in the pressure vessel 2 is released from the bottom, and it becomes difficult to maintain the internal pressure of the pressure vessel 2 at the pressure during pressurization. The pressure at the time of pressurization will be below.

  In the solid-liquid separation step, the amount of medium contained in the crude product P charged into the filter (pressure filter 1) (when all the crude products obtained in the polymerization step are charged into the filter) The amount of the medium used in the polymerization step) is preferably 100% by weight, and the medium contained in the crude product P is preferably removed by passing a medium of 70% by weight or more through the filter medium 3. In the solid-liquid separation step, a medium of 70% by weight or more is passed through the filter medium 3 with respect to 100% by weight of the medium contained in the crude product P charged into the filter (pressure filter 1). Thus, the remaining amount of the surfactant in the polymer particles remaining on the filter medium 3 can be reduced. As a result, it is possible to reduce the amount of cleaning liquid in the cleaning process described later.

  For example, when the pressure filter 1 is used as a filter in the solid-liquid separation step, the solid-liquid separation step includes the amount of the medium contained in the crude product P introduced into the pressure filter 1 ( When all the crude products P obtained in the polymerization step are put into the pressure filter 1, the amount of the medium is 70% by weight or more with respect to 100% by weight of the medium used in the polymerization step). 3 and it is preferable that the process is terminated when the internal pressure of the pressure vessel 2 becomes 80% or less with respect to the pressure of 100% during pressurization. As a result, the remaining amount of the surfactant in the polymer particles remaining on the filter medium 3 can be reliably reduced, and the amount of the cleaning liquid in the cleaning step described later can be reduced.

[Washing process]
In the washing step, the washing liquid is put into the filter holding the polymer particles on the filter medium, the washing liquid is brought into contact with the polymer particles, and the washing liquid in contact with the polymer particles passes through the filter medium. As a result, polymer particles washed with the washing liquid are obtained on the filter medium.

In the washing step, the amount per unit time of the washing liquid that has passed through the filter medium is the following conditional expression (2);
Y ≦ 8.50 × A (2)
(In Formula (2), Y means the amount (kg / min) per unit time of the cleaning liquid that has passed through the filter medium, and A represents the area (m ² ) of the interface between the filter medium and the object to be filtered). Means). When the amount per unit time of the cleaning liquid that has passed through the filter medium does not satisfy the conditional expression (2), the time for which the polymer particles are in contact with the cleaning liquid is short. The attached surfactant is not sufficiently removed, and a large amount of the surfactant may remain in the finally obtained polymer particles.

In addition, the amount per unit time of the cleaning liquid that has passed through the filter medium in the cleaning step averages from the start to the end of the cleaning of the polymer particles by allowing the cleaning liquid to pass through the filter medium. 3);
2.50 × A ≦ Y ≦ 8.50 × A (3)
(In Formula (3), Y means the amount (kg / min) of the cleaning liquid that has passed through the filter medium per unit time, and A means the area (m ² ) of the interface between the filter medium and the object to be filtered. It is preferable to satisfy. When the amount per unit time of the cleaning liquid that has passed through the filter medium in the cleaning step satisfies the above conditional expression (3), the surfactant adhering to the surface of the polymer particles can be sufficiently removed. The remaining amount of the surfactant in the finally obtained polymer particles can be reduced.

  For example, when the pressure filter 1 as shown in FIG. 1 is used in the solid-liquid separation step, the washing liquid is left while the polymer particle cake remaining on the filter medium 3 is held on the filter medium 3 as it is. The cake and the cleaning liquid are brought into contact with each other by being supplied into the pressure vessel 2, and the upper space S of the filter medium 3 is pressurized by supplying the compressed gas to the upper space S of the filter medium 3 in the pressure vessel 2 by a compressed gas supply machine. . As a result, the cake comes into contact with the cleaning liquid and is cleaned, and the cleaned cleaning liquid is discharged out of the pressure vessel 2 as a filtrate. In addition, after supplying a washing | cleaning liquid, before performing pressurization, you may slurry by mixing the washing | cleaning liquid supplied in the pressure-resistant container 2 using the stirrer with the said cake. Moreover, you may repair the crack of a cake using a stirrer before supplying the washing | cleaning liquid for washing | cleaning. Thereby, there is no short path for the cleaning liquid, and efficient cleaning can be performed.

  In the above washing step, the pressurizing condition when the pressurizing filter 1 is used to pressurize the upper space S of the filter medium 3 in the pressure resistant vessel 2 is particularly limited as long as it satisfies the conditional expression (2). However, for example, it is preferable to pressurize the pressure vessel 2 so that the internal pressure is within a range of 0.01 MPa to 0.50 MPa. Moreover, it is preferable that the upper space S of the filter medium 3 is pressurized at a speed of 0.01 to 0.30 MPa / min. In the cleaning process, it is preferable that the internal pressure of the pressure vessel 2 is kept substantially constant from the start of pressurization to the end of the cleaning step so as to satisfy the conditional expression (2). As for the internal pressure, the pressure in the pressure-resistant vessel 2 gradually decreases as the cleaning liquid introduced into the pressure-resistant vessel 2 passes through the filter medium 3 after being pressurized. Specifically, when the cleaning liquid passing through the filter medium 3 is reduced or almost disappeared, the compressed air pressure in the pressure resistant container 2 is released from the bottom, and it becomes difficult to maintain the internal pressure of the pressure resistant container 2 at the pressure at the time of pressurization. The pressure at the time of pressurization will be below.

  The cleaning liquid used in the cleaning step is preferably an aqueous medium, and examples thereof include water; lower alcohols such as methyl alcohol and ethyl alcohol (alcohols having 5 or less carbon atoms); and mixtures of water and lower alcohols. It is preferable to use the same medium as used in the polymerization step.

  The weight of the washing liquid used in the washing step is the weight of the polymer particles held on the filter medium 3 (in the case where all the crude products obtained in the polymerization step in the solid-liquid separation step are put into the filter, the polymerization step) The total amount of vinyl monomers used in (1) is 10 times or more. When the weight of the washing liquid used in the washing step is less than 10 times the weight of the polymer particles held on the filter medium 3, the removal of the surfactant contained in the polymer particles becomes insufficient, and the desired polymer There is a possibility that particles (polymer particles having a surfactant content of less than 50 ppm) cannot be obtained.

  In addition, the weight of the cleaning liquid used in the cleaning process is preferably equal to or more than the total amount of the lower limit D of the weight of the cleaning liquid calculated by the following calculation formula (4) for each type of surfactant used in the polymerization process. . When the weight of the cleaning liquid used in the cleaning process is equal to or more than the total amount of the lower limit D of the weight of the cleaning liquid calculated by the following calculation formula (4) for each type of surfactant used in the polymerization process, the polymer particles The content of the surfactant in the inside can be further reduced.

D = (E ÷ F) × 2000 (4)
D: Lower limit of weight of cleaning solution required for one type of surfactant (g)
E: Amount of the one kind of surfactant used (g)
F: Solubility (g / 100 ml) of the above-mentioned one type of surfactant in the washing liquid having a liquid temperature of 25 ° C.

  Moreover, it is preferable that the temperature of the washing | cleaning liquid used for washing | cleaning is a temperature from which surfactant is fully eluted, for example, it is preferable that it is 40-80 degreeC, and it is more preferable that it is 50-80 degreeC. In addition, as a method for heating the cleaning liquid to the above temperature and performing cleaning, a method of supplying the heated cleaning liquid to a filter (for example, the pressure vessel 2 of the pressure filter 1) may be used. A method of heating the cleaning liquid with a heater jacket disposed around the filter after being supplied to the filter may be used.

  In the cleaning step, the conductivity of the cleaning liquid that has passed through the filter medium 3 is 2.0 times or less the conductivity of the cleaning liquid before being charged into the filter (pressure filter 1), and the internal pressure of the pressure vessel 2 is It is preferable that the process is terminated when the pressure is 80% or less with respect to the pressure of 100% during pressurization. By introducing the cleaning liquid into the pressure resistant container 2 until the conductivity of the cleaning liquid that has passed through the filter medium 3 is 2.0 times or less of the conductivity of the cleaning liquid before being charged into the filter (pressure filter 1), The residual amount of the surfactant contained in the finally obtained polymer particles can be surely reduced. Further, the water that can be absorbed by the polymer particles by passing the cleaning liquid charged into the pressure vessel 2 through the filter medium 3 until the internal pressure of the pressure vessel 2 becomes 80% or less with respect to the pressure of 100% during pressurization. The amount can be reduced, and the time required for drying the polymer particles after washing can be shortened.

  The polymer particles obtained in the washing step are dried in a vacuum dryer to almost completely remove the washing liquid, and classified as necessary (preferably, air flow classification) to obtain a weight that can be used as a product. It can be combined particles.

  According to the method for producing polymer particles described above, in the solid-liquid separation step, the amount per unit time of the medium that has passed through the filter medium satisfies the conditional expression (1), and the unit time of the cleaning liquid that has passed through the filter medium in the washing step. Since the amount per hit satisfies the conditional expression (2) and the washing step uses a washing liquid having a weight of 10 times or more the weight of the polymer particles held on the filter medium, the polymer particles are used in the polymerization step. Most of the surfactant adhering to can be removed together with the medium and the cleaning liquid. As a result, it is possible to obtain polymer particles excellent in dispersion stability with a very small surfactant content (residual amount). Moreover, according to the said manufacturing method, the polymer dispersion stabilizer which can be used at a superposition | polymerization process is also removed in large quantities by a solid-liquid separation process and a washing | cleaning process. For this reason, the polymer particle obtained by the said manufacturing method can also become a thing with little quantity of a polymer dispersion stabilizer.

[Use of polymer particles]
The polymer particles of the present invention are suitable for optical films such as antiglare films and light diffusion films, and optical members such as light diffusers, and particularly suitable for antiglare members.

[Optical film]
The optical film of the present invention is obtained by coating a coating resin composition containing the polymer particles of the present invention and a binder on a film substrate. The optical film of the present invention is obtained, for example, by dispersing the polymer particles in a binder to obtain a coating resin composition, coating the obtained coating resin composition on a film substrate, It is obtained by forming a coating film made of the resin composition for use on the film substrate.

  The binder is not particularly limited as long as it is used in the field according to required properties such as transparency, polymer particle dispersibility, light resistance, moisture resistance and heat resistance. Examples of the binder include (meth) acrylic resins; (meth) acrylic-urethane resins; urethane resins; polyvinyl chloride resins; polyvinylidene chloride resins; melamine resins; styrene resins; alkyd resins. Phenol resin; epoxy resin; polyester resin; silicone resin such as alkylpolysiloxane resin; (meth) acrylic-silicone resin, silicone-alkyd resin, silicone-urethane resin, silicone-polyester resin, etc. Modified silicone resins; binder resins such as fluororesins such as polyvinylidene fluoride and fluoroolefin vinyl ether polymers.

  From the viewpoint of improving the durability of the coating resin composition, the binder resin is preferably a curable resin capable of forming a crosslinked structure by a crosslinking reaction. The curable resin can be cured under various curing conditions. The curable resin is classified into an ionizing radiation curable resin such as an ultraviolet curable resin and an electron beam curable resin, a thermosetting resin, a hot air curable resin, and the like depending on the type of curing.

  Examples of the thermosetting resin include thermosetting urethane resin composed of acrylic polyol and isocyanate prepolymer, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, and silicone resin.

  As the ionizing radiation curable resin, synthesized from polyfunctional (meth) acrylate resin such as polyhydric alcohol polyfunctional (meth) acrylate; diisocyanate, polyhydric alcohol, and (meth) acrylic acid ester having a hydroxy group And polyfunctional urethane acrylate resins. The ionizing radiation curable resin is preferably a polyfunctional (meth) acrylate resin, and more preferably a polyhydric alcohol polyfunctional (meth) acrylate having three or more (meth) acryloyl groups in one molecule. As polyhydric alcohol polyfunctional (meth) acrylate having 3 or more (meth) acryloyl groups in one molecule, specifically, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexanetetra (meth) acrylate, pentaglycerol triacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol triacrylate, tripentaerythritol hexaacrylate, etc. That. Two or more kinds of the ionizing radiation curable resins may be used in combination.

  As the ionizing radiation curable resin, besides these, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can also be used.

  When using an ultraviolet curable resin among the ionizing radiation curable resins, a photopolymerization initiator is added to the ultraviolet curable resin to form a binder. Although what kind of thing may be used for the said photoinitiator, it is preferable to use what was suitable for the ultraviolet curable resin to be used.

  Examples of the photopolymerization initiator include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, α-hydroxyalkylphenones, α-aminoalkylphenones, anthraquinones, thioxanthones, azo compounds, peroxides (Described in JP 2001-139663 A), 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, onium salts, borate salts, active halogen compounds, α-acyloximes Examples include esters.

  Examples of the acetophenones include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropio. Phenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone and the like can be mentioned. Examples of the benzoins include benzoin, benzoin benzoate, benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether. Examples of the benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone, p-chlorobenzophenone, and the like. Examples of the phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Examples of the ketals include benzylmethyl ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one. Examples of the α-hydroxyalkylphenones include 1-hydroxycyclohexyl phenyl ketone. Examples of the α-aminoalkylphenones include 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone.

  Commercially available radical photopolymerization initiators include trade names “Irgacure (registered trademark) 651” (2,2-dimethoxy-1,2-diphenylethane-1-one) manufactured by BASF Japan Ltd., manufactured by BASF Japan Ltd. Trade name “Irgacure (registered trademark) 184”, trade name “Irgacure (registered trademark) 907” manufactured by BASF Japan Ltd. (2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) ) -1-propanone) and the like.

  The usage-amount of the said photoinitiator is in the range of 0.5-20 weight% normally with respect to 100 weight% of binders, Preferably it exists in the range of 1-5 weight%.

  As the binder resin, a thermoplastic resin can be used in addition to the curable resin. Examples of the thermoplastic resin include cellulose derivatives such as acetylcellulose, nitrocellulose, acetylbutylcellulose, ethylcellulose, and methylcellulose; homopolymers and copolymers of vinyl acetate, homopolymers and copolymers of vinyl chloride, and vinylidene chloride. Vinyl resins such as homopolymers and copolymers; acetal resins such as polyvinyl formal and polyvinyl butyral; homopolymers and copolymers of acrylate esters, homopolymers and copolymers of methacrylate esters, etc. ) Acrylic resin; polystyrene resin; polyamide resin; linear polyester resin; polycarbonate resin.

  In addition to the binder resin, rubber binders such as synthetic rubber and natural rubber, inorganic binders, and the like can be used as the binder. Examples of the rubber binder resin include ethylene-propylene copolymer rubber, polybutadiene rubber, styrene-butadiene rubber, and acrylonitrile-butadiene rubber. These rubber-based binder resins may be used alone or in combination of two or more.

  Examples of the inorganic binder include silica sol, alkali silicate, silicon alkoxide, and phosphate. As the inorganic binder, an inorganic or organic-inorganic composite matrix obtained by hydrolysis and dehydration condensation of metal alkoxide or silicon alkoxide can also be used. As the inorganic or organic-inorganic composite matrix, a silicon oxide matrix obtained by hydrolysis and dehydration condensation of a silicon alkoxide such as tetraethoxysilane can be used. These inorganic binders may be used alone or in combination of two or more.

  The amount of the polymer particles in the coating resin composition is preferably 2 parts by weight or more, more preferably 4 parts by weight or more, based on 100 parts by weight of the solid content of the binder, and 6 parts by weight. More preferably, it is the above. By making the amount of the polymer particles 2 parts by weight or more with respect to 100 parts by weight of the solid content of the binder, it becomes easy to make the matte property of the coating film formed by the coating resin composition sufficient. Therefore, it becomes easy to make sufficient optical characteristics, such as anti-glare property and light diffusibility, of the film formed by coating the coating resin composition on the film substrate. The amount of the polymer particles in the coating resin composition is preferably 300 parts by weight or less, more preferably 200 parts by weight or less, and more preferably 100 parts by weight with respect to 100 parts by weight of the solid content of the binder. More preferably, it is as follows. By making the amount of the polymer particles 300 parts by weight or less with respect to 100 parts by weight of the solid content of the binder, the linear permeability of the coating film formed by the coating resin composition is easily made sufficient.

  The coating resin composition may further contain an organic solvent. When the coating resin composition is applied to a substrate such as a film substrate to be described later, the organic solvent is added to the coating resin composition so that the coating resin composition for the substrate is coated. The coating is not particularly limited as long as the coating is easy. Examples of the organic solvent include aromatic solvents such as toluene and xylene; alcohol solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and propylene glycol monomethyl ether; Ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone; 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, ethylene glycol dimethyl ether, ethylene Glycol ethers such as glycol diethyl ether, diethylene glycol dimethyl ether, and propylene glycol methyl ether; 2-methoxyethyl acetate Salts, glycol ether esters such as 2-ethoxyethyl acetate (cellosolve acetate), 2-butoxyethyl acetate, propylene glycol methyl ether acetate; chlorinated solvents such as chloroform, dichloromethane, trichloromethane, and methylene chloride Ether solvents such as tetrahydrofuran, diethyl ether, 1,4-dioxane, 1,3-dioxolane; amide solvents such as N-methylpyrrolidone, dimethylformamide, dimethyl sulfoxide, and dimethylacetamide can be used. These organic solvents may be used alone or in combination of two or more.

  The film substrate is preferably transparent. Examples of transparent film base materials include polyester polymers such as polyethylene terephthalate (PET) and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose (TAC), polycarbonate polymers, and polymethyl methacrylate. And a film made of a polymer such as a (meth) acrylic polymer. In addition, as a transparent film base material, polystyrene, styrene polymer such as acrylonitrile / styrene copolymer, polyethylene, polypropylene, polyolefin having cyclic or norbornene structure, olefin polymer such as ethylene / propylene copolymer, chloride A film made of a polymer such as a vinyl polymer or an amide polymer such as nylon or aromatic polyamide may also be mentioned. Further, as transparent film base materials, imide polymers, sulfone polymers, polyether sulfone polymers, polyether ether ketone polymers, polyphenyl sulfide polymers, vinyl alcohol polymers, vinylidene chloride. Examples thereof include films made of polymers such as polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers and blends of the above polymers. As the film substrate, those having a particularly low birefringence are preferably used. In addition, a film in which an easy-adhesion layer such as (meth) acrylic resin, copolymerized polyester resin, polyurethane resin, styrene-maleic acid graft polyester resin, acrylic graft polyester resin or the like is further provided on these films is also used as the film base. Can be used.

  The thickness of the film substrate can be determined as appropriate, but is generally in the range of 10 to 500 μm and in the range of 20 to 300 μm from the viewpoints of workability such as strength and handling, and thin layer properties. It is preferable that it is within a range of 30 to 200 μm.

  Moreover, you may add an additive to a film base material. Examples of the additive include an ultraviolet absorber, an infrared absorber, an antistatic agent, a refractive index adjuster, and an enhancer.

  The coating resin composition can be applied to a film substrate by bar coating, blade coating, spin coating, reverse coating, diting, spray coating, roll coating, gravure coating, micro gravure coating, lip coating, air Known coating methods such as knife coating and dipping method may be mentioned.

  When the binder contained in the coating resin composition is an ionizing radiation curable resin, after applying the coating resin composition, if necessary, the solvent is dried and further irradiated with active energy rays to cure the ionizing radiation. The curing resin may be cured.

  Examples of the active energy ray include ultraviolet rays emitted from a light source such as a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, and a tungsten lamp; Electron beams, α rays, β rays, γ rays and the like extracted from electron beam accelerators such as a type, a resonant transformation type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type can be used.

  The thickness of the layer in which the polymer particles are dispersed in the binder formed by application (and curing) of the coating resin composition is not particularly limited and is appropriately determined depending on the particle diameter of the polymer particles. It is preferably in the range of 10 to 10 μm, and more preferably in the range of 3 to 7 μm.

  Since the optical film of the present invention is formed by coating a substrate with the coating resin composition containing the polymer particles of the present invention having excellent dispersion stability, the entire coating film formed by the coating , Stable optical properties such as light diffusibility and antiglare properties can be obtained. Therefore, according to the optical film of the present invention, high quality stability can be obtained.

  The above-described optical film of the present invention can be suitably used for light diffusion or antiglare, that is, as a light diffusion film or antiglare film.

[Resin molding]
The resin molded body of the present invention is formed by molding a molding resin composition containing the polymer particles and a transparent resin. In the resin molded product of the present invention, the polymer particles function as light diffusing particles. Therefore, the resin molded body of the present invention functions as a light diffuser such as a light diffusing plate and can be used as an LED lighting cover or the like.

  The transparent resin is a base material of the resin molded body. For example, a (meth) acrylic resin, a polycarbonate resin, a polystyrene resin, a (meth) acrylic-styrene resin ((meth) acrylic) acid ester and styrene are used together. Polymer) and the like. Among these, polystyrene resin or (meth) acryl-styrene resin is preferable as the transparent resin.

  The amount of the polymer particles contained in the resin composition is preferably in the range of 0.01 to 5 parts by weight, and in the range of 0.1 to 5 parts by weight with respect to 100 parts by weight of the transparent resin. More preferably. You may add additives, such as a ultraviolet absorber, antioxidant, a heat stabilizer, a light stabilizer, and a fluorescent whitening agent, to the said resin composition.

  The thickness, shape, and the like of the resin molded body can be appropriately selected depending on the application of the resin molded body.

  The resin molded body of the present invention can be obtained by melt-kneading the transparent resin and the polymer particles with a single screw extruder or a twin screw extruder. Moreover, the resin composition obtained by melt kneading may be molded into a plate shape via a T die and a roll unit to obtain a resin molded body. Moreover, the resin composition obtained by melt kneading may be pelletized, and the pellet may be formed into a plate shape by injection molding or press molding to obtain a resin molded body.

  Since the resin molded body of the present invention is formed by molding a molding resin composition containing the polymer particles of the present invention having excellent dispersion stability, in the resin molded body, there is no uneven light diffusibility or Optical properties such as antiglare properties can be obtained stably. Therefore, according to the resin molding of the present invention, high quality stability can be obtained.

  Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this. First, in the following Examples and Comparative Examples, the volume average particle diameter of the polymer particles and the measurement method of the coefficient of variation of the particle diameter, the measurement method of the volume average particle diameter of the seed particles used for the production of the polymer particles, the polymer Method for measuring X value (amount of medium per unit time that passed through filter medium (kg / min)) in solid-liquid separation process of particle production, Y value (cleaning liquid that passed through filter medium) in washing process of polymer particle production For measuring the amount per unit time (kg / min), measuring method for surfactant content in polymer particles (measuring method by liquid chromatography mass spectrometry (LC-MS-MS)) polymer particles The measurement method by TOF-SIMS, the measurement method of the gel fraction of polymer particles, and the measurement method of the dispersion stabilization time of polymer particles will be described.

[Measurement method of volume average particle diameter of polymer particles and coefficient of variation of particle diameter]
The volume average particle size is measured by Coulter Multisizer III (measurement device manufactured by Beckman Coulter, Inc.). The measurement shall be performed using an aperture calibrated according to the Multisizer ^™ 3 User's Manual issued by Beckman Coulter, Inc.

  In addition, the selection of the aperture used for the measurement is such that when the assumed volume average particle diameter of the polymer particles to be measured is 1 μm or more and 10 μm or less, an aperture having a size of 50 μm is selected, and the assumed volume average of the polymer particles to be measured When the particle diameter is larger than 10 μm and 30 μm or less, an aperture having a size of 100 μm is selected. When the assumed volume average particle diameter of the polymer particles is larger than 30 μm and not larger than 90 μm, an aperture having a size of 280 μm is selected, When the assumed volume average particle diameter of the polymer particles is greater than 90 μm and 150 μm or less, an aperture having a size of 400 μm is selected. When the volume average particle diameter after measurement is different from the assumed volume average particle diameter, the aperture is changed to an aperture having an appropriate size, and measurement is performed again.

  When an aperture having a size of 50 μm is selected, Current (aperture current) is set to −800, Gain (gain) is set to 4, and when an aperture having a size of 100 μm is selected, Current (aperture current) is − 1600, Gain (gain) is set to 2, and when apertures having sizes of 280 μm and 400 μm are selected, Current (aperture current) is set to −3200 and Gain (gain) is set to 1.

  As a sample for measurement, 0.1 g of polymer particles in a 0.1% by weight nonionic surfactant aqueous solution 10 ml, a touch mixer (manufactured by Yamato Kagaku Co., Ltd., “TOUCHMIXER MT-31”) and an ultrasonic cleaner (stock) Dispersed using “ULTRASONIC CLEANER VS-150” (manufactured by Vervo Crea) and used as a dispersion. Set a beaker filled with ISOTON (registered trademark) II (manufactured by Beckman Coulter Co., Ltd .: electrolyte for measurement) in the measuring section of Coulter Multisizer III, and drop the dispersion while gently stirring the inside of the beaker. Then, after the concentration meter reading on the Coulter Multisizer III main body screen is adjusted to 5 to 10%, the measurement is started. During the measurement, the beaker is gently stirred to the extent that bubbles do not enter, and the measurement is terminated when 100,000 polymer particles are measured. The volume average particle diameter of the polymer particles is an arithmetic average in a volume-based particle size distribution of 100,000 particles.

  The coefficient of variation (CV value) of the particle diameter of the polymer particles is calculated by the following formula.

  Coefficient of variation of particle diameter of polymer particles = (standard deviation of volume distribution of polymer particles / volume average particle diameter of polymer particles) × 100

[Method for measuring volume average particle diameter of seed particles]
The volume average particle diameter of the seed particles is measured by a laser diffraction / scattering particle size distribution measuring device (“LS 13 320” manufactured by Beckman Coulter, Inc.) and a universal liquid sample module.

  For measurement, 0.1 g of seed particles was added to 10 ml of 0.1% by weight nonionic surfactant aqueous solution with a touch mixer (manufactured by Yamato Kagaku Co., Ltd., “TOUCMIXER MT-31”) and an ultrasonic cleaner (Velvok Co., Ltd.). Dispersed using “ULTRASONIC CLEANER VS-150” manufactured by Leer, and used as a dispersion.

  In addition, in the laser diffraction / scattering type particle size distribution measuring device software described above, the following optical parameters required for evaluation based on the Mie theory are set.

<Parameter>
Real part of refractive index BI of liquid (nonionic surfactant aqueous solution) = 1.333 (refractive index of water)
Real part of refractive index of solid (seed particle to be measured) = refractive index of seed particle Imaginary part of refractive index of solid = 0
Solid form factor = 1
Measurement conditions and measurement procedures are as follows.

<Measurement conditions>
Measurement time: 60 seconds Number of measurements: 1
Pump speed: 50-60%
PIDS relative concentration: about 40-55% Ultrasonic output: 8
<Measurement procedure>
After performing offset measurement, optical axis adjustment, and background measurement, the above-described dispersion liquid is injected into the universal liquid sample module of the laser diffraction / scattering particle size distribution measuring apparatus using a dropper. When the concentration in the universal liquid sample module reaches the PIDS relative concentration and the software of the laser diffraction / scattering particle size distribution measuring apparatus displays “OK”, the measurement is started. Note that the measurement is performed in a state where the seed particles are dispersed by performing pump circulation in the universal liquid sample module and an ultrasonic unit (ULM ULTRASONIC MODULE) is activated.

  In addition, the measurement is performed at room temperature, and the volume average particle diameter of the seed particles is determined from the obtained data using the software parameters of the laser diffraction / scattering type particle size distribution measuring apparatus, using the preset optical parameters. (Arithmetic mean diameter in the volume-based particle size distribution) is calculated.

  The refractive index of the seed particles was measured by inputting the refractive index of the polymer constituting the seed particles. For example, since the polymer constituting the seed particles used in the production of Examples and Comparative Examples described later is polymethyl methacrylate or polyethyl methacrylate, the known refraction of polymethyl methacrylate and polyethyl methacrylate is known. A rate of 1.495 was entered.

[Measurement method of X value]
In the solid-liquid separation step, a time T ₁ (min) from the start of passing the medium contained in the crude product through the filter medium to the end of the passage of the medium through the filter medium is measured. Further, the total weight G ₁ (kg) of the filtrate (medium) obtained in the solid-liquid separation step is weighed. And the quantity X (kg / min) per unit time of the medium which passed the filter medium is calculated | required with the following calculation formulas.
X (kg / min) = G ₁ (kg) / T ₁ (min)

[Measurement method of Y value]
The weight G ₂ (kg) of the cleaning liquid used in the cleaning process is measured. Further, in the cleaning process, after the cleaning liquid was started to pass through the filter medium, the cleaning liquid having a weight 0.8 times the weight G ₂ (g) of the cleaning liquid used in the cleaning process was spent passing through the filter medium. Time T ₂ (min) is measured. And the quantity Y (kg / min) per unit time of the washing | cleaning liquid which passed the filter medium is calculated | required with the following calculation formulas.
Y (kg / min) = 0.8 × G ₂ (kg) / T ₂ (min)

[Method for measuring content of surfactant in polymer particles]
The content of the surfactant in the polymer particles is measured by extracting the polymer particles with a solvent and using a liquid chromatograph mass spectrometer (LC / MS / MS apparatus).

In addition, for the measurement of the content of the surfactant in the polymer particles of Examples and Comparative Examples described later, as a LC / MS / MS apparatus, “UHPLC ACCELA” manufactured by Thermo Fisher Scientific and “manufactured by Thermo Fisher Scientific” "Linear Ion Trap LC / MS ⁿ LXQ" was used.

  In addition, polymer particles in Examples and Comparative Examples to be described later are di (2-ethylhexyl) sulfosuccinate, polyoxyethylene styrenated phenyl ether sulfate (see Formula (A) described later), as a surfactant. Using at least one of alkenyl succinate (see formula (C) below) and polyoxyethylene styrenated phenyl ether (see formula (E) below) The content of the surfactant in the polymer particles was measured by the following method.

  About 0.10 g of polymer particles as a sample are precisely weighed in a centrifuge tube, and 5 mL of methanol as an extract is poured with a whole pipette to mix the polymer particles and the extract well. After ultrasonic extraction for 15 minutes, centrifugation is performed at 3500 rpm for 15 minutes, and the resulting supernatant is used as a test solution.

  The surfactant concentration in the test solution is measured using an LC / MS / MS apparatus. The measured surfactant concentration (μg / ml) in the test solution, the weight of the polymer particles used as the sample (sample weight (g)), and the amount of the extract (extract solution amount (ml)) From the above, the content (μg / g) of the surfactant in the polymer particles is determined by the following calculation formula. The amount of the extract is 5 ml.

Surfactant content (μg / g)
= {Surfactant concentration in test solution (µg / ml) x Extraction liquid amount (ml)} ÷ Sample weight (g)

  The surfactant concentration is calculated from a calibration curve prepared in advance from the peak area value on the obtained chromatogram using an LC / MS / MS apparatus. Further, when the polymer particles contain a plurality of types of surfactants, for each of these surfactants, create a calibration curve, calculate the surfactant concentration using the created calibration curve, and calculate each The total surfactant concentration of the surfactant is defined as the “surfactant concentration (μg / ml) in the test solution” in the above calculation formula, and the content of the surfactant in the polymer particles is determined.

  The calibration curve creation method is as follows according to the type of surfactant used in the examples and comparative examples.

-Method for preparing calibration curve of di (2-ethylhexyl) sulfosuccinate-
After preparing about 1000 ppm intermediate standard solution (methanol solution) of di (2-ethylhexyl) sulfosuccinate, it is further diluted stepwise with methanol to 0.1 ppm, 0.2 ppm, 0.5 ppm, 1.0 ppm, and 2. A standard solution for preparing a 0 ppm calibration curve is prepared. A standard solution for preparing a calibration curve at each concentration was measured under the LC measurement conditions and MS measurement conditions described later, and on the chromatogram of monitor ion m / z = 421.3 (precursor ion) → 227.2 (product ion). Obtain the peak area value. Each concentration and area value are plotted to obtain an approximate curve (secondary curve) by the least square method, and this is used as a calibration curve for quantification.

-Preparation of calibration curve for polyoxyethylene styrenated phenyl ether sulfate ester salt-
After preparing about 1000 ppm intermediate standard solution (methanol solution) of polyoxyethylene styrenated phenyl ether sulfate ester, it is further diluted stepwise with methanol to 0.1 ppm, 0.5 ppm, 1.0 ppm, 2.0 ppm, 10 ppm A standard solution for preparing a calibration curve of 0.0 ppm is prepared. A standard solution for preparing a calibration curve at each concentration was measured under the LC measurement conditions and MS measurement conditions described later, and on the chromatogram of monitor ion m / z = 601.4 (precursor ion) → 301.2 (product ion). Obtain the peak area value. Each concentration and area value are plotted to obtain an approximate curve (secondary curve) by the least square method, and this is used as a calibration curve for quantification.

-Method for preparing calibration curve of alkenyl succinate-
After preparing about 1000ppm intermediate standard solution (methanol solution) of alkenyl succinate, further dilute stepwise with methanol to create 0.03ppm, 0.15ppm, 0.60ppm, 1.5ppm, 3.0ppm calibration curves Prepare a standard solution. A standard solution for preparing a calibration curve at each concentration was measured under the LC measurement conditions and MS measurement conditions described later, and on the chromatogram of monitor ion m / z = 339.3 (precursor ion) → 295.2 (product ion). Obtain the peak area value. Each concentration and area value are plotted to obtain an approximate curve (secondary curve) by the least square method, and this is used as a calibration curve for quantification.

-Method for preparing calibration curve of polyoxyethylene styrenated phenyl ether-
After preparing about 1000 ppm intermediate standard solution (methanol solution) of polyoxyethylene styrenated phenyl ether, it is further diluted stepwise with methanol to 0.1 ppm, 0.5 ppm, 2.5 ppm, 5.0 ppm, 10.0 ppm. Prepare a standard solution for preparing a calibration curve. A standard solution for preparing a calibration curve at each concentration was measured under the LC measurement conditions and MS measurement conditions described later, and on the chromatogram of monitor ion m / z = 980.5 (precursor ion) → 963.2 (product ion). Obtain the peak area value. Each concentration and area value are plotted to obtain an approximate curve (secondary curve) by the least square method, and this is used as a calibration curve for quantification.

  The LC measurement conditions according to the type of surfactant used in the examples and comparative examples are as follows.

-LC measurement conditions for di (2-ethylhexyl) sulfosuccinate, polyoxyethylene styrenated phenyl ether sulfate, and polyoxyethylene styrenated phenyl ether-
Measuring apparatus: UHPLC ACCELA (manufactured by Thermo Fisher Scientific)
Column: Hypersil GOLD C18 1.9 μm (inner diameter 2.1 mm, length 100 mm) manufactured by Thermo Fisher Scientific
Column temperature: 40 ° C
Mobile phase: (A: 10 mM ammonium acetate / B: acetonitrile)
Mobile phase conditions: (0 min = B concentration 90%, 0 → 0.5 min = B concentration 90% → 100%, 0.5 → 1 min = B concentration 100%, 1 → 1.1 min = B concentration 100% → 90% 1.1 → 3min = B concentration 90%)
Flow rate: 0.3 mL / min
Pump temperature: room temperature (25 ° C)
Injection volume: 2 μL
Measurement time: 3 min

-LC measurement conditions for alkenyl succinate-
Measuring apparatus: UHPLC ACCELA (manufactured by Thermo Fisher Scientific)
Column: Hypersil GOLD C18 1.9 μm (inner diameter 2.1 mm, length 100 mm) manufactured by Thermo Fisher Scientific
Column temperature: 40 ° C
Mobile phase: (A: 10 mM ammonium acetate / B: acetonitrile = 25/75)
Flow rate: 0.3 mL / min
Pump temperature: room temperature (25 ° C)
Injection volume: 2 μL
Measurement time: 5 min

  MS measurement conditions according to the type of surfactant used in Examples and Comparative Examples are as follows.

-MS measurement conditions for di (2-ethylhexyl) sulfosuccinate-
Measuring device: Linear Ion Trap LC / MS ⁿ LXQ (manufactured by Thermo Fisher Scientific)
Ionization: (ESI / negative)
Sheath gas: 30 arb
Auxiliary gas (AUX Gas): 10arb
Sweep Gas: 0arb
Spray voltage (I Spray Voltage): 5.0 kV
Capillary temperature: 350 ° C.
Capillary voltage: -20V
Tube lens voltage: -100V
Monitoring ion (m / Z): di (2-ethylhexyl) sulfosuccinate (n = 421.3 / n2 = 227.2)

-MS measurement conditions for polyoxyethylene styrenated phenyl ether sulfate-
Measuring device: Linear Ion Trap LC / MS ⁿ LXQ (manufactured by Thermo Fisher Scientific)
Ionization: (ESI / negative)
Sheath gas: 30 arb
Auxiliary gas (AUX Gas): 10arb
Sweep Gas: 0arb
Spray voltage (I Spray Voltage): 5.0 kV
Capillary temperature: 350 ° C.
Capillary voltage: -20V
Tube lens voltage: -100V
Monitoring ion (m / Z): polyoxyethylene styrenated phenyl ether sulfate ester salt (n = 601.4 / n2 = 301.2)

-MS measurement conditions for alkenyl succinate-
Measuring device: Linear Ion Trap LC / MS ⁿ LXQ (manufactured by Thermo Fisher Scientific)
Ionization: (ESI / negative)
Sheath gas: 30 arb
Auxiliary gas (AUX Gas): 10arb
Sweep Gas: 0arb
Spray voltage (I Spray Voltage): 5.0 kV
Capillary temperature: 350 ° C.
Capillary voltage: -20V
Tube lens voltage: -100V
Monitoring ion (m / Z): alkenyl succinate (n = 339.3 / n2 = 295.3)

-MS measurement conditions for polyoxyethylene styrenated phenyl ether-
Measuring device: Linear Ion Trap LC / MS ⁿ LXQ (manufactured by Thermo Fisher Scientific)
Ionization: (ESI / negative)
Sheath gas: 30 arb
Auxiliary gas (AUX Gas): 10arb
Sweep Gas: 0arb
Spray voltage (I Spray Voltage): 5.0 kV
Capillary temperature: 350 ° C.
Capillary voltage: -20V
Tube lens voltage: -100V
Monitoring ion (m / Z): polyoxyethylene styrenated phenyl ether (n = 980.5 / n2 = 963.2)

[Measurement method of polymer particles by TOF-SIMS]
The polymer particles (sample) are measured by a time-of-flight secondary ion mass spectrometer (TOF-SIMS), and it is confirmed that a peak derived from the surfactant is detected.

  For example, the polymer particles are fixed to a sample stage of a time-of-flight secondary ion mass spectrometer (“TOF-SIMS 5” manufactured by ION-TOF), and measurement is performed under the following measurement conditions. For the measurement, a positive electron gun is used to detect both positive and negative secondary ions, and then it is confirmed that a peak derived from the surfactant is detected.

<Measurement conditions>
Primary ion: Bi ₃ ²⁺
Primary ion acceleration voltage: 25 kV
Measurement area: 200μm square

  In Examples and Comparative Examples, a peak derived from a surfactant (anionic surfactant and / or nonionic surfactant) is detected. Therefore, the ratio of the ionic strength of the negative ions derived from the surfactant to the sum of the total ionic strength of the positive ions and the total ionic strength of the negative ions, measured by the time-of-flight secondary ion mass spectrometer, is expressed as Obtained as intensity ratio.

Specifically, in Examples 1 to 7 and Comparative Examples 1 and 2, anionic surfactant sodium di (2-ethylhexyl) sulfosuccinate is used as the surfactant. In measurement by a secondary ion mass spectrometer, a plurality of negative ion fragment peaks derived from sodium di (2-ethylhexyl) sulfosuccinate are detected. Among the detected negative ion fragments derived from sodium di (2-ethylhexyl) sulfosuccinate, di (2-ethylhexyl) sulfosuccinate ion (molecular formula: C ₂₀ H ₃₇ SO ₇ ⁻ , molecular weight 421) is the highest ion. Since it shows strength, in Examples 1 to 7 and Comparative Examples 1 and 2, di (2-ethylhexyl) sulfosuccinate ion (molecular formula: C ₂₀ H ₃₇ SO ₇ ⁻ , molecular weight 421) is used as an evaluation ion species, and positive ions The ratio of the ionic strength of di (2-ethylhexyl) sulfosuccinate ion to the total of the total ionic strength and negative ionic strength is determined as the ionic strength ratio.

In Example 8, polyoxyethylene styrenated phenyl ether sulfate ammonium represented by the following formula (A), which is an anionic surfactant, is used as the surfactant. In the measurement using an ion mass spectrometer, a plurality of negative ion fragment peaks derived from polyoxyethylene styrenated phenyl ether ammonium sulfate represented by the following formula (A) are detected. Among the negative ion fragments derived from ammonium polyoxyethylene styrenated phenyl ether sulfate ester represented by the following formula (A) to be detected, styrenated phenyloxy ion represented by the following formula (B) (molecular formula: C ₂₂ H ₂₁ O ⁻ , molecular weight 301) shows the highest ionic strength, and in Example 8, styrenated phenyloxy ion (molecular formula: C ₂₂ H ₂₁ O ⁻ , molecular weight 301) was used as an evaluation ion species, and positive The ratio of the ionic strength of a styrenated phenyloxy ion (molecular formula: C ₂₂ H ₂₁ O ⁻ , molecular weight 301) represented by the following formula (B) to the sum of the total ionic strength of ions and the total ionic strength of negative ions, Obtained as ionic strength ratio.

(In formula (A), n means the number of repeating units of an ethyleneoxy group (—CH ₂ CH ₂ O—).)

Moreover, in Example 9, dipotassium alkenyl succinate represented by the following formula (C), which is an anionic surfactant, is used as the surfactant, and measurement using the time-of-flight secondary ion mass spectrometer is performed. , A plurality of negative ion fragment peaks derived from dipotassium alkenyl succinate represented by the following formula (C) are detected, and the negative ion species having the highest ionic strength is represented by the following formula (D1) or (D2). Was detected (molecular formula: C ₂₀ H ₃₅ O ₄ ⁻ , molecular weight 339). That is, among the negative ion fragments derived from dipotassium alkenyl succinate represented by the following formula (C) to be detected, monovalent ions of alkenyl succinic acid represented by the following formula (D1) or formula (D2) ( Since the molecular formula: C ₂₀ H ₃₅ O ₄ ⁻ , molecular weight 339) shows the highest ionic strength, in Example 9, a monovalent ion of alkenyl succinic acid represented by the following formula (D1) or formula (D2) (Molecular formula: C ₂₀ H ₃₅ O ₄ ⁻ , molecular weight 339) is an evaluation ion species, and is expressed by the following formula (D1) or formula (D2) with respect to the sum of the total ionic strength of positive ions and the total ionic strength of negative ions. The ratio of the ionic strength of monovalent ions of alkenyl succinic acid (molecular formula: C ₂₀ H ₃₅ O ₄ ⁻ , molecular weight 339) is determined as the ionic strength ratio.

  (In the formula (C), R means an alkenyl group.)

  (In Formula (D1) and Formula (D2), R ′ means an alkenyl group having 16 carbon atoms.)

In Example 10, as the surfactant, polyoxyethylene styrenated phenyl ether sulfate ammonium represented by the above formula (A) which is an anionic surfactant and the following formula (nonionic surfactant): E) and polyoxyethylene styrenated phenyl ether represented by the above formula (A) in the time-of-flight secondary ion mass spectrometer. Multiple peaks of negative ion fragments derived from ammonium ether sulfate and polyoxyethylene styrenated phenyl ether represented by the following formula (E) are detected. Among the negative ion fragments derived from the polyoxyethylene styrenated phenyl ether sulfate ammonium represented by the above formula (A) and the polyoxyethylene styrenated phenyl ether represented by the following formula (E): Since the styrenated phenyloxy ion represented by the formula (B) (molecular formula: C ₂₂ H ₂₁ O ⁻ , molecular weight 301) exhibits the highest ionic strength, in Example 10, it is represented by the formula (B). The styrenated phenyloxy ion (molecular formula: C ₂₂ H ₂₁ O ⁻ , molecular weight 301) is an evaluation ion species, and is represented by the above formula (B) with respect to the sum of the total ionic strength of positive ions and the total ionic strength of negative ions. that styrenated phenyloxy ion (molecular _{formula: C} 22 _{H 21} O ^-, molecular weight 301) the ratio of the ionic strength of Io Determined as the intensity ratio.

(In formula (E), n means the number of repeating units of an ethyleneoxy group (—CH ₂ CH ₂ O—).)

[Method for measuring gel fraction of polymer particles]
In a 200 mL eggplant flask, 1.0 g of polymer particles as a sample and 0.03 g of boiling stone are precisely weighed and added, and further 100 mL of toluene is added, and then a cooling tube is attached to the eggplant flask. The eggplant flask is immersed in an oil bath maintained at ° C. and refluxed for 24 hours.

  After refluxing, the contents (dissolved solution) in the eggplant flask were weighed with glass fiber filters “GB-140 (φ37 mm)” and “GA-200 (φ37 mm)” manufactured by ADVANTEC, and manufactured by TOP. Filtration is performed using a Buchner funnel filter 3G (glass particle pore diameter 20-30 μm, volume 30 mL), and the solid content is recovered in the Buchner funnel filter 3G. Then, the solid content collected in the Buchner funnel filter 3G is dried together with the Buchner funnel filter 3G in a vacuum oven at 130 ° C. for 1 hour, and then dried at a gauge pressure of 0.06 MPa for 2 hours. And cool to room temperature.

  After cooling, the Buchner funnel filter 3G, the glass fiber filter, and the total weight of the solid matter were measured in a state where the Buchner funnel filter 3G contained the solid matter. Then, the weight (g) of the dry powder was obtained by subtracting the weight of the Buchner funnel filter 3G and the glass fiber filter and the weight of the boiling stone from the measured total weight.

And the gel fraction was computed with the following formulas using the weight (g) of dry powder, and the weight (g) of the sample put into the eggplant flask.
Gel fraction (% by weight) = {Dry powder (g) / Sample weight (g)} × 100

[Method for measuring dispersion stabilization time of polymer particles]
The viscosity value of the dispersion liquid in which the polymer particles are dispersed in the dispersion medium changes as the dispersion state of the polymer particles in the dispersion liquid changes. Therefore, after preparing the dispersion, the viscosity value of the dispersion is measured every hour to determine the change rate of the viscosity value, and the time required for the obtained change rate to be within a predetermined range, The time (dispersion stabilization time) required for stabilizing the dispersion state of the polymer particles in the dispersion was measured.

  Specifically, the time required for the change rate to fall within a predetermined range was measured by the following method.

(1) Dispersion Preparation Method To a 10 ml sample tube, 0.15 g of polymer particles and 0.90 g of methyl ethyl ketone as a dispersion medium are added, and an ultrasonic cleaner (“ULTRASONIC CLEANER VS manufactured by Velvo Crea Co., Ltd.) is added. -150 ") for 1 minute to disperse the polymer particles in methyl ethyl ketone to obtain a dispersion. To this dispersion, 2.10 g of acrylic resin (“Acridic (registered trademark) A-811” manufactured by DIC Corporation) was further added, and the mixture was stirred for about 2 minutes with the ultrasonic cleaner, and methyl ethyl ketone and Polymer particles are dispersed in an acrylic resin to prepare a dispersion.

(2) Measuring method of viscosity value The viscosity value of a dispersion liquid is measured by the following method using a viscometer (a trace sample viscometer m-VROC manufactured by Nippon Luft Co., Ltd.). Note that the viscometer is left in the measurement environment for 30 minutes or more in advance before measuring the viscosity value.

The dispersion liquid to be measured is stirred for 30 minutes with an ultrasonic cleaner and then allowed to stand for 10 minutes, and then the viscosity (mPa · s) of the dispersion liquid is measured using the viscometer. And the viscosity value V (mPa * s / K) per unit temperature (K) is calculated | required by the following formula using the measured value (mPa * s) of viscosity, and measured temperature (K).
Viscosity value V (mPa · s / K) = Measured value (mPa · s) ÷ Measured temperature (K)

(3) Dispersion stabilization time measurement method The viscosity value V (mPa · s / K) of the dispersion is measured every 1 hour from the preparation of the dispersion according to the above viscosity value measurement method. The viscosity value V of the measured dispersion is V _T (mPa · s / K), and the viscosity value of 1 hour before this dispersion is V _T-1 (mPa · s / K). The rate W (%) is obtained.
W = ((V _T−1 −V _T ) / V _T−1 ) × 100

  The viscosity value is measured every other hour until the rate of change W is in the range of more than -1% to less than 1%. Then, after the dispersion was prepared, the elapsed time T until the change rate W of the viscosity value was in the range of more than -1% to less than 1% was measured, and the elapsed time T was defined as the dispersion stabilization time.

[Seed Particle Production Example 1]
In a separable flask equipped with a stirrer, a thermometer and a reflux condenser, 1000 g of water as an aqueous medium, 180 g of ethyl methacrylate as a (meth) acrylic acid ester monomer, and n-octyl mercaptan as a molecular weight regulator 3.6 g was charged, the inside of the separable flask was purged with nitrogen while stirring the contents of the separable flask, and the internal temperature of the separable flask was raised to 55 ° C. Furthermore, while maintaining the internal temperature of the separable flask at 55 ° C., an aqueous solution in which 0.9 g of potassium persulfate as a polymerization initiator was dissolved in 80 g of water was added to the contents in the separable flask and then polymerized for 12 hours. Reacted. The reaction solution after polymerization was filtered through a 400 mesh (mesh size: 32 μm) wire mesh to prepare a slurry containing 14% by weight of seed particles (referred to as seed particles (1)) composed of polyethyl methacrylate as a solid content. The seed particles (1) contained in this slurry were true spherical particles having a volume average particle diameter of 0.76 μm.

[Seed Particle Production Example 2]
In a 5 L reactor equipped with a stirrer and a thermometer, 450 g of methyl methacrylate as a (meth) acrylic acid ester monomer, 4.5 g of n-octyl mercaptan as a molecular weight regulator, and as a polymerization initiator 2,2′-Azobisisobutyronitrile (4.5 g) was mixed. The obtained mixture was added to 1800 g of ion-exchanged water against sodium di (2-ethylhexyl) sulfosuccinate (“RAPISOL (registered trademark) A-80” manufactured by NOF Corporation) and water at a liquid temperature of 25 ° C. as a surfactant. (Solubility: 1.5 g / 100 ml) is added to a pure component of 4.5 g and mixed with a homomixer (“TK homomixer MARK 2.5 type” manufactured by PRIMIX Corporation) at 8000 rpm for 10 minutes. And an emulsion was obtained.

  To the emulsion in the reactor, the slurry of the seed particles (1) produced in Seed Particle Production Example 1 is added to 12.6 g as a solid content (seed particles), and is allowed to stand at room temperature for 5 hours. Stir. Thereafter, 900 g of an aqueous solution in which 15 g of polyvinyl pyrrolidone (“PVP-90” manufactured by Kuraray Co., Ltd.) as a polymer dispersion stabilizer was dissolved was put into the reactor and polymerized at 55 ° C. for 12 hours with stirring. It was.

  The reaction solution after polymerization is filtered with a 400 mesh (mesh size 32 μm) wire mesh and contains 14% by weight of seed particles (hereinafter referred to as seed particles (2)) composed of polyethyl methacrylate and polymethyl methacrylate as solids. A slurry was prepared. The seed particles (2) contained in this slurry were true spherical particles having a volume average particle diameter of 2.30 μm.

[Example 1: Production example of polymer particles]
(1) Polymerization step 280 g of methyl methacrylate (MMA) as a (meth) acrylic acid ester monomer, 280 g of styrene (St) as a styrene monomer, and ethylene as a polyfunctional vinyl monomer A monomer mixture obtained by dissolving 240 g of glycol dimethacrylate (EGDMA), 4 g of 2,2′-azoisobutyronitrile as a polymerization initiator, and 4 g of benzoyl peroxide as a polymerization initiator, To 800 g of ion-exchanged water as an aqueous medium, sodium di (2-ethylhexyl) sulfosuccinate as an anionic surfactant (“Lapisol (registered trademark) A-80” manufactured by NOF Corporation), with respect to water at a liquid temperature of 25 ° C. Solubility: 1.5 g / 100 ml) is added to the pure 8 g added and mixed with a homomixer (Primics Co., Ltd. “T Put the K Homomixer MARK 2.5 inch ") to obtain an emulsion solution for 10 minutes at 10000 rpm. To this emulsion, the slurry of seed particles (1) obtained in Seed Particle Production Example 1 was added to a solid content (seed particles) of 4.2 g, and stirred at 30 ° C. for 5 hours. Got.

  In this dispersion, 40 g of polyvinyl alcohol (“GOHSENOL (registered trademark) GM-14L” manufactured by Nippon Synthetic Chemical Co., Ltd.) as a polymer dispersion stabilizer and 0.64 g of sodium nitrite as a polymerization inhibitor are dissolved. 2400 g of the aqueous solution was added, and then the polymerization reaction was carried out by stirring at 60 ° C. for 5 hours and then at 105 ° C. for 3 hours to obtain a slurry of polymer particles (hereinafter referred to as slurry (1)) as a crude product. .

(2) Solid-liquid separation step The slurry (1) of polymer particles as the crude product P is charged into the pressure resistant container 2 of the pressure filter 1 having the configuration shown in FIG. After the polymer cloth slurry (1) is filled on the filter cloth (“T713” manufactured by Shikishima Canvas Co., Ltd.), the compressed gas is supplied to the upper space S of the filter medium 3 in the pressure vessel 2 by the compressed gas supply machine. By supplying, the inside of the pressure vessel 2 (specifically, the upper space S of the filter medium 3) was pressurized to 0.08 MPa. Thereby, the slurry (1) of polymer particles as the crude product P was subjected to pressure filtration and dehydration, and water as an aqueous medium was removed from the slurry (1) of polymer particles as a filtrate. When the amount of the filtrate is 2.24 kg (70% of the weight of the water used in the polymerization step) or more and the internal pressure of the pressure vessel 2 is 0.064 MPa (80% of the pressure during pressurization) or less, Pressurization was terminated. As a result, a cake of polymer particles was obtained on the filter medium 3. In addition, the interface between the filter medium 3 (filter cloth) of the pressure filter 1 used in this embodiment and the material to be filtered (that is, the crude product P) is circular, and the diameter thereof is that of the pressure vessel 2. It is 0.115 m, which is the same as the diameter of the bottom surface of the internal space (the diameter indicated by the symbol R in FIG. 1). Therefore, the area A of the interface between the filter medium 3 (filter cloth) of the pressure filter 1 used in this example and the material to be filtered (that is, the crude product P) is 0.0104 m ² . The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.46 kg, and the medium (water) contained in the crude product P is started to pass through the filter medium 3. Then, the time T ₁ until the passage of the medium through the filter medium 3 was 55.7 minutes.

(3) Washing step After the cake of the polymer particles is held on the filter medium 3, water as a cleaning liquid is supplied onto the filter medium 3 in the pressure vessel 2, and then the filter medium in the pressure vessel 2 by a compressed gas supply machine. The compressed gas was supplied to the upper space S of 3 to pressurize the inside of the pressure vessel 2 (specifically, the upper space S of the filter medium 3) to 0.08 MPa. Thereby, pressure filtration and dehydration were performed to wash the cake of the polymer particles, and the washed water was removed as a filtrate to obtain washed polymer particles on the filter medium 3. The washing is performed using a washing liquid having a weight 10 times or more the weight of the polymer particles obtained in the polymerization process (total amount of vinyl monomers used in the polymerization process 800 g). The test was performed until the electric conductivity of water was 2.0 times or less (specifically, 15 μS or less), and the internal pressure of the pressure vessel 2 was 0.064 MPa (80% of the pressure during pressurization) or less. The weight G ₂ of water as the cleaning liquid used in the cleaning step of this example is 12 kg (15 times the weight of the polymer particles obtained in the polymerization step), and the surfactant used in the polymerization step. More than the total amount 10.7 kg (8 (g) ÷ 1.5 (g / 100 ml) × 2000 = 10667 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type It was a heavy weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent for the cleaning liquid to pass through the filter medium 3 was 230.8 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Example 2: Production example of polymer particles]
In the solid-liquid separation step, the inside of the pressure vessel 2 is pressurized to 0.15 MPa, the amount of the filtrate becomes 2.24 kg (70% of the weight of water used in the polymerization step) or more, and the internal pressure of the pressure vessel 2 is 0. The target polymer particles were obtained in the same manner as in Example 1 except that the solid-liquid separation step was terminated when the pressure became .12 MPa (80% of the pressure during pressurization) or less. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.48 kg, and the medium (water) contained in the crude product P starts to pass through the filter medium 3. Then, the time T ₁ until the passage of the medium through the filter medium 3 was 46.6 minutes. The weight G ₂ of water as the cleaning liquid used in the cleaning step of this example is 12 kg (15 times the weight of the polymer particles obtained in the polymerization step), and the surfactant used in the polymerization step. More than the total amount 10.7 kg (8 (g) ÷ 1.5 (g / 100 ml) × 2000 = 10667 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type It was a heavy weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent until the cleaning liquid passed through the filter medium 3 was 355.6 minutes.

[Example 3: Production Example of Polymer Particles]
(1) Polymerization step Similar to the polymerization step of Example 1, except that the amount of the slurry of seed particles (1) obtained in Seed Particle Production Example 1 was changed to 16.7 g as the solid content (seed particles). Thus, a slurry of polymer particles (hereinafter referred to as slurry (2)) was obtained as a crude product.

(2) Solid-liquid separation step Instead of the polymer particle slurry (1), the polymer particle slurry (2) is used as the crude product, the inside of the pressure vessel 2 is pressurized to 0.20 MPa, and the filtrate is added. The solid-liquid separation step when the amount of water becomes 2.24 kg (70% of the weight of water used in the polymerization step) or more and the internal pressure of the pressure vessel 2 becomes 0.16 MPa (80% of the pressure during pressurization) or less. The water as an aqueous medium was removed from the slurry (2) of polymer particles in the same manner as in the solid-liquid separation step of Example 1 except that the process was terminated. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.38 kg, and the medium (water) contained in the crude product P starts to pass through the filter medium 3. Then, the time T ₁ from the end of the passage of the medium through the filter medium 3 was 73.9 minutes.

(3) Washing process The inside of the pressure vessel 2 is pressurized to 0.20 MPa, and the electrical conductivity of the filtrate is 2.0 times or less (specifically, 15 μS or less) of the water before washing, and the pressure vessel A cake of polymer particles on the filter medium 3 was prepared in the same manner as in the washing step of Example 1 except that washing was performed until the internal pressure of No. 2 was 0.16 MPa (80% of the pressure during pressurization) or less. The polymer particles after washing were obtained on the filter medium 3. The weight G ₂ of water as the cleaning liquid used in the cleaning step of this example is 12 kg (15 times the weight of the polymer particles obtained in the polymerization step), and the surfactant used in the polymerization step. More than the total amount 10.7 kg (8 (g) ÷ 1.5 (g / 100 ml) × 2000 = 10667 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type It was a heavy weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent for the cleaning liquid to pass through the filter medium 3 was 346.6 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Example 4: Production Example of Polymer Particles]
(1) Polymerization step As seed particles, the seed particle (1) slurry obtained in seed particle production example 1 is obtained in seed particle production example 2 in place of 4.2 g as the solid content (seed particles). Polymer particle slurry (hereinafter referred to as slurry (3)) in the same manner as in the polymerization step of Example 1 except that 18.7 g of the seed particle (2) slurry was used as the solid content (seed particle). Was obtained as a crude product.

(2) Solid-liquid separation step Instead of the polymer particle slurry (1), the polymer particle slurry (3) is used as the crude product, the inside of the pressure vessel 2 is pressurized to 0.15 MPa, and the filtrate is added. The solid-liquid separation step when the amount of water becomes 2.24 kg (70% of the weight of water used in the polymerization step) or more and the internal pressure of the pressure vessel 2 becomes 0.12 MPa (80% of the pressure during pressurization) or less. The water as an aqueous medium was removed from the polymer particle slurry (3) in the same manner as in the solid-liquid separation step of Example 1 except that the process was terminated. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.50 kg, and the medium (water) contained in the crude product P is started to pass through the filter medium 3. Then, the time T ₁ until the passage of the medium through the filter medium 3 was 49.7 minutes.

(3) Washing process The inside of the pressure vessel 2 is pressurized to 0.20 MPa, and the electrical conductivity of the filtrate is 2.0 times or less (specifically, 15 μS or less) of the water before washing, and the pressure vessel A cake of polymer particles on the filter medium 3 was prepared in the same manner as in the washing step of Example 1 except that washing was performed until the internal pressure of No. 2 was 0.16 MPa (80% of the pressure during pressurization) or less. The polymer particles after washing were obtained on the filter medium 3. The weight G ₂ of water as the cleaning liquid used in the cleaning step of this example is 12 kg (15 times the weight of the polymer particles obtained in the polymerization step), and the surfactant used in the polymerization step. More than the total amount 10.7 kg (8 (g) ÷ 1.5 (g / 100 ml) × 2000 = 10667 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type It was a heavy weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent until the cleaning liquid passed through the filter medium 3 was 119.7 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Example 5: Production example of polymer particles]
(1) Polymerization step In the monomer mixture, styrene (St) as a styrene monomer is not blended, and the amount of methyl methacrylate (MMA) as a (meth) acrylic ester monomer is blended. A slurry of polymer particles (hereinafter referred to as a slurry) was prepared in the same manner as in the polymerization step of Example 1 except that the amount was 560 g and the blending amount of ethylene glycol dimethacrylate (EGDMA) as a polyfunctional vinyl monomer was 240 g. (4)) was obtained as a crude product.

(2) Solid-liquid separation step Instead of the polymer particle slurry (1), the polymer particle slurry (4) is used as the crude product, the inside of the pressure vessel 2 is pressurized to 0.15 MPa, and the filtrate is added. The solid-liquid separation step when the amount of water becomes 2.24 kg (70% of the weight of water used in the polymerization step) or more and the internal pressure of the pressure vessel 2 becomes 0.12 MPa (80% of the pressure during pressurization) or less. The water as an aqueous medium was removed from the slurry (4) of polymer particles in the same manner as in the solid-liquid separation process of Example 1 except that the process was terminated. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.48 kg, and the medium (water) contained in the crude product P starts to pass through the filter medium 3. Then, the time T ₁ from the end of the passage of the medium through the filter medium 3 was 46.1 minutes.

(3) Washing process The inside of the pressure vessel is pressurized to 0.15 MPa, and the conductivity of the filtrate becomes 2.0 times or less (specifically, 15 μS or less) of the water before washing, and the pressure vessel 2 The cake of polymer particles on the filter medium 3 is washed in the same manner as in the washing step of Example 1 except that washing is performed until the internal pressure of 0.12 MPa or less (80% of the pressure at the time of pressurization) is reduced. Then, polymer particles after washing were obtained on the filter medium 3. The weight G ₂ of water as the cleaning liquid used in the cleaning step of this example is 12 kg (15 times the weight of the polymer particles obtained in the polymerization step), and the surfactant used in the polymerization step. More than the total amount 10.7 kg (8 (g) ÷ 1.5 (g / 100 ml) × 2000 = 10667 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type It was a heavy weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent until the cleaning liquid passed through the filter medium 3 was 263.7 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Example 6: Production example of polymer particles]
(1) Polymerization step In the monomer mixture, methyl methacrylate (MMA) as a (meth) acrylic acid ester monomer is not blended, and the blending amount of styrene (St) as a styrene monomer is changed. A slurry of polymer particles (hereinafter referred to as a slurry) was prepared in the same manner as in the polymerization step of Example 1 except that the amount was 560 g and the blending amount of ethylene glycol dimethacrylate (EGDMA) as a polyfunctional vinyl monomer was 240 g. (5)) was obtained as a crude product.

(2) Solid-liquid separation step Instead of the polymer particle slurry (1), the polymer particle slurry (5) is used as a crude product, the inside of the pressure vessel 2 is pressurized to 0.15 MPa, and the filtrate is added. The solid-liquid separation step when the amount of water becomes 2.24 kg (70% of the weight of water used in the polymerization step) or more and the internal pressure of the pressure vessel 2 becomes 0.12 MPa (80% of the pressure during pressurization) or less The water as an aqueous medium was removed from the slurry (5) of polymer particles in the same manner as in the solid-liquid separation step of Example 1 except that the process was terminated. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.48 kg, and the medium (water) contained in the crude product P starts to pass through the filter medium 3. Then, the time T ₁ until the passage of the medium through the filter medium 3 was 45.3 minutes.

(3) Cleaning step The inside of the pressure vessel 2 is pressurized to 0.10 MPa, and the conductivity of the filtrate is 2.0 times or less (specifically, 15 μS or less) of the water before washing, and the pressure vessel A cake of polymer particles on the filter medium 3 was prepared in the same manner as in the cleaning step of Example 1 except that the cleaning was performed until the internal pressure of 2 became 0.08 MPa (80% of the pressure at the time of pressurization) or less. The polymer particles after washing were obtained on the filter medium 3. The weight G ₂ of water as the cleaning liquid used in the cleaning step of this example is 12 kg (15 times the weight of the polymer particles obtained in the polymerization step), and the surfactant used in the polymerization step. More than the total amount 10.7 kg (8 (g) ÷ 1.5 (g / 100 ml) × 2000 = 10667 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type It was a heavy weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent for the cleaning liquid to pass through the filter medium 3 was 183.6 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Example 7: Production example of polymer particles]
(1) Polymerization step In the monomer mixture, methyl methacrylate (MMA) as a (meth) acrylic acid ester monomer is not blended, and the blending amount of styrene (St) as a styrene monomer is changed. 560 g, a polymer similar to the polymerization step of Example 1 except that 240 g of divinylbenzene (DVB) was blended in place of 240 g of ethylene glycol dimethacrylate (EGDMA) as the polyfunctional vinyl monomer. A slurry of particles (hereinafter referred to as slurry (6)) was obtained as a crude product.

(2) Solid-liquid separation process
As a crude product, instead of the polymer particle slurry (1), the polymer particle slurry (6) was used, the inside of the pressure vessel 2 was pressurized to 0.10 MPa, and the amount of filtrate was 2.24 kg ( Except that the solid-liquid separation process was completed when the pressure of the pressure vessel 2 became equal to or greater than 70% of the weight of water used in the polymerization process and the internal pressure of the pressure vessel 2 became equal to or less than 0.08 MPa (80% of the pressure during pressurization). In the same manner as in the solid-liquid separation step of Example 1, water as an aqueous medium was removed from the slurry (6) of polymer particles. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.50 kg, and the medium (water) contained in the crude product P is started to pass through the filter medium 3. Then, the time T ₁ until the passage of the medium through the filter medium 3 was completed was 77.2 minutes.

(3) Washing process The inside of the pressure vessel 2 is pressurized to 0.15 MPa, and the conductivity of the filtrate becomes 2.0 times or less (specifically, 15 μS or less) of the water before washing, and the pressure vessel A cake of polymer particles on the filter medium 3 was prepared in the same manner as in the washing step of Example 1 except that washing was performed until the internal pressure of 2 was 0.12 MPa (80% of the pressure at the time of pressurization) or less. The polymer particles after washing were obtained on the filter medium 3. The weight G ₂ of water as the cleaning liquid used in the cleaning step of this example is 12 kg (15 times the weight of the polymer particles obtained in the polymerization step), and the surfactant used in the polymerization step. More than the total amount 10.7 kg (8 (g) ÷ 1.5 (g / 100 ml) × 2000 = 10667 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type It was a heavy weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent until the cleaning liquid passed through the filter medium 3 was 151.9 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Example 8: Production example of polymer particles]
(1) Polymerization Step As an anionic surfactant, sodium di (2-ethylhexyl) sulfosuccinate (“Lapisol (registered trademark) A-80” manufactured by NOF Corporation, solubility in water at a liquid temperature of 25 ° C .; 5 g / 100 ml) is replaced with 8 g as a pure component, and ammonium polyoxyethylene styrenated phenyl ether sulfate represented by the above formula (A) (“Hitenol (registered trademark) NF08” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) A slurry of polymer particles (hereinafter referred to as slurry (7)) was used in the same manner as in the polymerization step of Example 1 except that 8 g was used as a pure component (solubility in water at a liquid temperature of 25 ° C .; 1.2 g / 100 ml). Was obtained as a crude product.

(2) Solid-liquid separation step As the crude product, the same procedure as in the solid-liquid separation step of Example 1 was performed except that the polymer particle slurry (7) was used instead of the polymer particle slurry (1). Then, water as an aqueous medium was removed from the slurry (7) of polymer particles. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.44 kg, and the medium (water) contained in the crude product P is started to pass through the filter medium 3. Then, the time T ₁ until the passage of the medium through the filter medium 3 was 60.1 minutes.

(3) Washing Step In the same manner as in the washing step of Example 1, the polymer particle cake on the filter medium 3 was washed to obtain washed polymer particles on the filter medium 3. The weight G ₂ of water as a cleaning solution used in the washing step of the present embodiment is 15.0 kg (18.75 times the weight of the resulting polymer particles in the polymerization process), used in the polymerization step 13.3 kg (8 (g) ÷ 1.2 (g / 100 ml) × 2000 = 13333 (g) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type of surfactant )). It was. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 12.0 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent for the cleaning liquid to pass through the filter medium 3 was 311.7 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Example 9: Production example of polymer particles]
(1) Polymerization Step As an anionic surfactant, sodium di (2-ethylhexyl) sulfosuccinate (“Lapisol (registered trademark) A-80” manufactured by NOF Corporation, solubility in water at a liquid temperature of 25 ° C .; 5 g / 100 ml) is replaced by 8 g as a pure component, and dipotassium alkenyl succinate represented by the above formula (C) (“Ramtel ASK” manufactured by Kao Corporation, solubility in water at a liquid temperature of 25 ° C .; 1.7 g / A slurry of polymer particles (hereinafter referred to as slurry (8)) was obtained as a crude product in the same manner as in the polymerization step of Example 1 except that 8 g of 100 ml) was used as a pure component.

(2) Solid-Liquid Separation Step As the crude product, the same procedure as in the solid-liquid separation step of Example 1 was performed except that the polymer particle slurry (8) was used instead of the polymer particle slurry (1). Then, water as an aqueous medium was removed from the slurry (8) of polymer particles. The total weight G ₁ of the solid-liquid filtrate obtained in the separation step of the present example (medium) is 2.49Kg, start to pass the medium (water) to the filter medium 3 contained in the crude product P Then, the time T ₁ until the passage of the medium through the filter medium 3 was 62.0 minutes.

(3) Washing Step In the same manner as in the washing step of Example 1, the polymer particle cake on the filter medium 3 was washed to obtain washed polymer particles on the filter medium 3. Surfactants The weight G ₂ of water as a cleaning solution used in the washing step of the present embodiment is 12.0 kg (15 times the weight of the resulting polymer particles in the polymerization step), which was used in the polymerization step 9.4 kg (8 (g) ÷ 1.7 (g / 100 ml) × 2000 = 9412 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type of activator It was more than the weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent for the cleaning liquid to pass through the filter medium 3 was 250.7 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Example 10: Production example of polymer particles]
(1) Polymerization Step As an anionic surfactant, sodium di (2-ethylhexyl) sulfosuccinate (“Lapisol (registered trademark) A-80” manufactured by NOF Corporation, solubility in water at a liquid temperature of 25 ° C .; 5 g / 100 ml) is replaced with 8 g as a pure component, and ammonium polyoxyethylene styrenated phenyl ether sulfate represented by the above formula (A) (“Hitenol (registered trademark) NF08” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 8g as a pure component is used as a polymer dispersion stabilizer ("GOHSENOL (registered trademark) GM-14L" manufactured by Nippon Synthetic Chemical Co., Ltd.). ]) In place of 40 g, polyoxyethylene styrenated phenyl represented by the above formula (E) as a nonionic surfactant Example 1 except that 8 g of ether (“Neugen® EA-167” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solubility in water at a liquid temperature of 25 ° C .; 1.1 g / 100 ml) was used as a pure component. In the same manner as in the polymerization step, a slurry of polymer particles (hereinafter referred to as slurry (9)) was obtained as a crude product.

(2) Solid-liquid separation step As the crude product, the same procedure as in the solid-liquid separation step of Example 1 was conducted except that the polymer particle slurry (9) was used instead of the polymer particle slurry (1). Then, water as an aqueous medium was removed from the slurry (9) of polymer particles. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.44 kg, and the medium (water) contained in the crude product P is started to pass through the filter medium 3. Then, the time T ₁ from the end of the passage of the medium through the filter medium 3 was 65.8 minutes.

(3) Washing Step In the same manner as in the washing step of Example 1, the polymer particle cake on the filter medium 3 was washed to obtain washed polymer particles on the filter medium 3. The weight G ₂ of water as a cleaning solution used in the washing step of the present embodiment is 30.0 kg (37.5 times the weight of the resulting polymer particles in the polymerization process), used in the polymerization step 27.9 kg ({8 (g) ÷ 1.2 (g / 100 ml) × 2000) of the amount of the lower limit value D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type of surfactant + {8 (g) ÷ 1.1 (g / 100 ml) × 2000} = 13333 + 14545 = 27878 (g)). In the cleaning process of this example, 24.0 kg (0.8 times the weight G ₂ of the water used as the cleaning liquid in the cleaning process) was started after the cleaning liquid started to pass through the filter medium 3. The time T ₂ (min) spent for the cleaning liquid to pass through the filter medium 3 was 633.2 minutes.

(4) Post-treatment step The polymer particles after washing obtained in the washing step are dried with a vacuum dryer, and an air classifier ("Turbo Classifier (TC-15)" manufactured by Nissin Engineering Co., Ltd.) is used. To obtain the desired polymer particles.

[Comparative Example 1: Comparative production example of polymer particles]
(1) Polymerization step In the same manner as in the polymerization step of Example 1, a slurry of polymer particles (hereinafter referred to as slurry (1)) was obtained as a crude product.

(2) Solid-liquid separation process The inside of the pressure vessel 2 is pressurized to 0.10 MPa, the amount of the filtrate becomes 2.24 kg (70% of the weight of water used in the polymerization step) or more, and the internal pressure of the pressure vessel 2 is A slurry of polymer particles (1) was obtained in the same manner as in the solid-liquid separation step of Example 1, except that the solid-liquid separation step was terminated when the pressure became 0.08 MPa (80% of the pressure during pressurization) or less. ) To remove water as an aqueous medium. The total weight G ₁ of the solid-liquid filtrate obtained in the separation step of the present example (medium) is 2.49Kg, start to pass the medium (water) to the filter medium 3 contained in the crude product P Then, the time T ₁ from the end of the passage of the medium through the filter medium 3 was 82.5 minutes.

(3) the weight _{G 2} of water as a cleaning liquid used in the cleaning process the washing step was 4.0 kg (5 times the weight of the resulting polymer particles in the polymerization process), pressurizing the interior of the pressure vessel 2 to 0.10MPa Without confirming that the conductivity of the filtrate is 2.0 times or less (specifically, 15 μS or less) of the water before washing, and the internal pressure of the pressure vessel 2 is 0.08 MPa (pressurization). The cake of polymer particles on the filter medium 3 is washed in the same manner as in the washing step of Example 1 except that washing is performed until the pressure becomes 80% or less of the pressure at the time of pressure. Polymer particles were obtained. In the cleaning process of this example, 3.2 kg (0.8 times the weight G ₂ of the weight of water as the cleaning liquid used in the cleaning process) was started after the cleaning liquid started to pass through the filter medium 3. The time T ₂ (min) spent for the cleaning liquid to pass through the filter medium 3 was 74.1 minutes.

[Comparative Example 2: Comparative production example of polymer particles]
(1) Polymerization step In the same manner as in the polymerization step of Example 1, a slurry of polymer particles (hereinafter referred to as slurry (1)) was obtained as a crude product.

(2) Solid-liquid separation process The inside of the pressure vessel 2 is pressurized to 0.25 MPa, the amount of the filtrate becomes 2.24 kg (70% of the weight of water used in the polymerization step) or more, and the internal pressure of the pressure vessel 2 is A slurry of polymer particles (1) was obtained in the same manner as in the solid-liquid separation step of Example 1 except that the solid-liquid separation step was terminated when the pressure became 0.20 MPa (80% of the pressure during pressurization) or less. ) To remove water as an aqueous medium. The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.45 kg, and the medium (water) contained in the crude product P is started to pass through the filter medium 3. Then, the time T ₁ until the passage of the medium through the filter medium 3 was 19.5 minutes.

(3) Washing process The water used as a washing liquid is used in an amount of 8.0 kg (10 times the weight of the polymer particles obtained in the polymerization process) or more, and the inside of the pressure vessel 2 is pressurized to 0.20 MPa to conduct the filtrate. Except that cleaning was performed until the rate became 2.0 times or less the conductivity of water before cleaning, and the internal pressure of the pressure vessel 2 became 0.16 MPa (80% of the pressure at the time of pressurization) or less. The cake of polymer particles on the filter medium 3 was washed in the same manner as in the washing step 1 to obtain polymer particles after washing on the filter medium 3. Surfactants The weight G ₂ of water as a cleaning solution used in the washing step of the present embodiment is 12.0 kg (15 times the weight of the resulting polymer particles in the polymerization step), which was used in the polymerization step Total amount 10.7 kg (8 (g) ÷ 1.5 (g / 100 ml) × 2000 = 10667 (g)) of the lower limit D of the weight of the cleaning liquid calculated by the above calculation formula (4) for each type of activator It was more than the weight. Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 9.6 kg of (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) The time T ₂ (min) spent for the cleaning liquid to pass through the filter medium 3 was 80.2 minutes.

  Regarding Examples 1 to 10 and Comparative Examples 1 and 2, the number of the slurry of polymer particles obtained in the polymerization step (slurry No.), the composition of the monomer mixture constituting the polymer contained in this slurry (polymer) Composition), measurement result of X value in solid-liquid separation process (amount of medium passing through filter medium per unit time (kg / min)), Y value in cleaning process (amount of cleaning liquid passed through filter medium per unit time ( kg / min)), the amount (kg) of the cleaning liquid (water) used in the cleaning step, the volume average particle size (μm) of the obtained polymer particles, and the coefficient of variation (CV value (%)). ) Measurement results, the compound name of the surfactant (used in the polymerization step) contained in the obtained polymer particles, the measurement result of the surfactant content (ppm) in the obtained polymer particles, TOF-SIMS of the obtained polymer particles Measurement results (ratio of ionic strength of negative ions derived from surfactant to total ionic strength of positive ions and total ionic strength of negative ions (ionic strength ratio), gel fraction of the obtained polymer particles (%) Measurement results and measurement results of dispersion stabilization time of polymer particles (elapsed time T from the preparation of the dispersion until the rate of change in viscosity value exceeds -1% to less than 1%) It shows in Table 1. Moreover, the detail of the measurement result by TOF-SIMS of the polymer particle of Examples 1-10 and Comparative Examples 1-2, specifically, the ion of the fragment of the positive ion detected by TOF-SIMS Depending on the total strength (total ionic strength of positive ions), the total ionic strength of fragments of negative ions detected by TOF-SIMS (total ionic strength of negative ions), and the surfactant detected by TOF-SIMS Negative ion (evaluation ion species) showing the highest ion intensity among the coming negative ions, the ion intensity of this negative ion (evaluation ion species), and the sum of the total ion intensity of positive ions and the total ion intensity of negative ions Table 2 shows the ionic strength ratio of negative ions (evaluated ionic species) (ie, ionic strength ratio).

The filter medium 3 (filter cloth) and the filtrate (ie, crude product P) of the pressure filter 1 (see FIG. 1) used in the solid-liquid separation process and the washing process of Examples 1 to 10 and Comparative Examples 1 and 2 The area A of the interface is 0.0104 (m ² ). For this reason, in Examples 1-10 and Comparative Examples 1-2, the upper limit value of the X value (the amount per unit time of the medium that has passed through the filter medium (kg / min)) represented by the conditional expression (1) is 0.0572 kg / min. In addition, the upper limit value of the Y value (the amount of the cleaning liquid that has passed through the filter medium per unit time (kg / min)) represented by the conditional expression (2) is 0.0884 kg / min.

  From the results shown in Table 1, the X value in the solid-liquid separation step and the Y value in the washing step are each not more than the above upper limit, and the amount of washing liquid (water) used for washing is not less than 8.0 kg (of the polymer particles). The polymer particles obtained in Examples 1 to 10 which are 10 times or more of the weight are compared with the amount of the washing liquid (water) used for washing being less than 8.0 kg (less than 10 times the weight of the polymer particles). Compared to the polymer particles obtained in Example 1 and the polymer particles obtained in Comparative Example 2 in which the X value in the solid-liquid separation step and the Y value in the washing step are larger than the upper limit, the ionic strength ratio is small, It was found that the amount of surfactant on the surface of the polymer particles was small. That is, according to the production method of the present invention, it was recognized that the amount of the surfactant used in the polymerization step on the surface of the polymer particles can be reduced by the solid-liquid separation step and the washing step.

  Further, the polymer particles of Examples 1 to 10 in which the surfactant content is in the range of more than 0 ppm to less than 50 ppm, compared with the polymer particles of Comparative Example 1 in which the surfactant content is 156 ppm, When dispersed in a dispersion medium to form a dispersion, the time until the viscosity value of the dispersion is stabilized (that is, the time until the rate of change of the viscosity value exceeds -1% to less than 1%) is short. It was. That is, the polymer particles of Examples 1 to 10 having a surfactant content in the range of more than 0 ppm to less than 50 ppm, compared to the polymer particles of Comparative Example 1 having a surfactant content of 156 ppm, It was recognized that the time until the dispersion medium was uniformly dispersed was short.

[Example 11: Production example of optical film]
To a 10 ml sample tube, 0.15 g of the polymer particles obtained in Example 1 and 0.90 g of methyl ethyl ketone were added, and an ultrasonic cleaner (“ULTRASONIC CLEANER VS-150” manufactured by VervoCrea Inc.) was added. And stirred for 1 minute to disperse the polymer particles in methyl ethyl ketone to obtain a dispersion. To this dispersion, 2.10 g of an acrylic resin (“Acridic (registered trademark) A-811” manufactured by DIC Corporation) was added and stirred for about 2 minutes with the ultrasonic cleaner. A resin composition was obtained. After this coating resin composition was allowed to stand for 12 hours, 5.40 g of methyl ethyl ketone was added to the coating resin composition, and the mixture was stirred for 1 minute with the ultrasonic cleaner to dilute the coating resin composition. Got.

  The resulting dilution of the coating resin composition was coated on a PET film using a 75 μm slit coater. After coating, the film was placed in a drier maintained at 70 ° C. and left for 1 hour to obtain an optical film.

[Example 12: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 2 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Example 13: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 3 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Example 14: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 4 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Example 15: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 5 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Example 16: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 6 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Example 17: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 7 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Example 18: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 8 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Example 19: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 9 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Example 20: Production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Example 10 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Comparative Example 3: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Comparative Example 1 was used instead of 0.15 g of the polymer particles obtained in Example 1.

[Comparative Example 4: Comparative production example of optical film]
Instead of 0.15 g of the polymer particles obtained in Example 1, 0.15 g of the polymer particles obtained in Comparative Example 1 was used, and the standing time of the coating resin composition was changed from 12 hours to 24 hours. The optical film was obtained like Example 11 except having changed.

[Comparative Example 5: Comparative Production Example of Optical Film]
An optical film was obtained in the same manner as in Example 11 except that 0.15 g of the polymer particles obtained in Comparative Example 2 was used instead of 0.15 g of the polymer particles obtained in Example 1.

  About the optical film of Examples 11-20 and Comparative Examples 3-5, the optical characteristic was evaluated by the method shown below.

[Evaluation method of optical characteristics]
A test piece is obtained by cutting an optical film into a 6 cm × 6 cm square shape. According to JIS K 7136, the haze of each of the four ends of the upper, lower, left, and right sides of the surface of the test piece coated with the coating resin composition and the central portion (total of five locations) manufactured by Nippon Denshoku Industries Co., Ltd. Measured using “NDH-4000”. Then, using the measured maximum value, minimum value, and average value of the haze (%) at five locations, the haze difference (%) is calculated by the following calculation formula, and the haze difference (%) is calculated as follows: Evaluation was based on the evaluation criteria.

<Calculation formula of haze difference (%)>
R = {(Hz _MAX −Hz _MIN ) / Hz _AVE )} × 100
R: Haze difference (%)
Hz _MAX : Maximum value of 5 hazes (%) Hz _MIN : Minimum value of 5 hazes (%) Hz _AVE : Average value of 5 hazes (%) <Evaluation Criteria>
◎: Haze difference is less than 0.5% ○: Haze difference is 0.5% or more and less than 1.0% △: Haze difference is 1.0% or more and less than 3.0% ×: Haze difference is 3.0 or more

  About the optical film of Examples 11-20 and Comparative Examples 3-5, the Example number and surfactant content of the polymer particle used for manufacture of an optical film, the stationary time of the resin composition for coating, and optics Table 3 shows the evaluation results of the optical properties of the film.

  An optical film (optical film of Examples 11 to 20) obtained by coating a coating resin composition containing polymer particles having a surfactant content in the range of more than 0 ppm and less than 50 ppm is a surfactant. Compared with an optical film (Comparative Examples 3 to 5) formed by coating a coating resin composition containing polymer particles having a polymer content of 50 ppm or more, the haze difference is small and the light diffusibility is small. It was recognized that That is, it was confirmed that stable optical characteristics (antiglare property and light diffusibility) can be obtained in the optical film containing polymer particles having a surfactant content in the range of more than 0 ppm and less than 50 ppm.

  Further, from the results shown in Table 1, the polymer particles of Comparative Example 1 having a surfactant content of 50 ppm or more have a stable viscosity when the standing time is 16 hours or more, and are uniformly dispersed in the dispersion medium. In the production of the optical film of Comparative Example 4, the standing time of the coating resin composition was set to 24 hours, and the polymer particles were contained in the coating resin composition. Although it was made to disperse | distribute uniformly, in Table 3, as for the optical film of the comparative example 4, the haze difference was large and the stable optical characteristic was not acquired.

  On the other hand, the polymer particles of Examples 1 to 10 having a surfactant content in the range of more than 0 ppm to less than 50 ppm and Comparative Example 2 having a surfactant content of 59 ppm are shown in Table 1. From the results shown in the above, it was confirmed that the viscosity was stable and dispersed uniformly in the dispersion medium (dispersion state was stabilized) in a short time of 11 to 13 hours. Therefore, in the production of the optical films of Examples 11 to 20 using the polymer particles of Examples 1 to 10 and the production of the optical film of Comparative Example 5 using the polymer particles of Comparative Example 2, the resin composition for coating is used. The standing time of the product was set to 12 hours so that the polymer particles were uniformly dispersed in the coating resin composition.

  As a result, as shown in Table 3, in Examples 11 to 20 produced using the polymer particles of Examples 1 to 10 having a surfactant content in the range of more than 0 ppm to less than 50 ppm. In the optical film, the haze difference was small and stable optical characteristics were obtained. On the other hand, in the optical film of the comparative example 5 produced using the comparative example 2 whose content of surfactant is 59 ppm, the haze difference is large compared with the optical film of Examples 11-20, and the stable optical characteristic. Was not obtained.

  From this, the polymer particles having a surfactant content in the range of more than 0 ppm to less than 50 ppm are coated on the film substrate with a coating resin composition obtained by dispersing the polymer particles in a binder. In the process of forming a coating film by processing, the dispersion state in the resin composition can be maintained almost stably, and the dispersion stability can be imparted to the optical film with stable optical properties. I can say that. Further, as described above, the optical film obtained by coating the coating resin composition containing polymer particles having a surfactant content in the range of more than 0 ppm to less than 50 ppm has a small haze difference and is optical. It can be said that the characteristics are stable and the quality is excellent.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  This application claims priority based on Japanese Patent Application No. 2013-204577 filed in Japan on September 30, 2013. By this reference, the entire contents thereof are incorporated into the present application.

DESCRIPTION OF SYMBOLS 1 Pressure filter 2 Pressure-resistant container 3 Filter medium R The diameter P of the interface (liquid removal surface) of a filter medium and a to-be-filtered material R Crude product S Upper space of filter medium

Claims (8)

A method for producing polymer particles, comprising:
A polymerization step in which a vinyl monomer is polymerized in the presence of a surfactant in a liquid medium to obtain a crude product including the polymer particles including the surfactant and the medium;
The crude product is charged into a filter, and the medium contained in the charged crude product is allowed to pass through the filter medium of the filter while the polymer particles contained in the crude product are retained on the filter medium. A liquid separation step;
By introducing a cleaning liquid into the filter holding the polymer particles on the filter medium, bringing the cleaning liquid into contact with the polymer particles, and passing the cleaning liquid in contact with the polymer particles through the filter medium, A washing step of obtaining polymer particles washed with the washing liquid on the filter medium,
In the solid-liquid separation step, the amount per unit time of the medium that has passed through the filter medium is the following conditional expression (1);
X ≦ 5.50 × A (1)
(In Formula (1), X means the amount (kg / min) per unit time of the medium that has passed through the filter medium, and A represents the area (m ² ) of the interface between the filter medium and the material to be filtered). Meaning)
In the washing step, the amount per unit time of the washing liquid that has passed through the filter medium is the following conditional expression (2):
Y ≦ 8.50 × A (2)
(In Formula (2), Y means the amount (kg / min) per unit time of the cleaning liquid that has passed through the filter medium, and A represents the area (m ² ) of the interface between the filter medium and the material to be filtered). Means)
In the washing step, a method for producing polymer particles using a washing liquid having a weight 10 times or more the weight of the polymer particles held on the filter medium ,
The method for producing polymer particles, wherein the cleaning liquid is water . It is a manufacturing method of the polymer particle according to claim 1 ,
The polymerization step comprises seeding a vinyl monomer in the presence of seed particles and a surfactant in a liquid medium, and a crude product containing the polymer particles containing the surfactant and the medium. A process for producing polymer particles, comprising obtaining A method for producing the polymer particles according to claim 1 or 2,
The method for producing polymer particles, wherein the filter is a pressure filter. It is a manufacturing method of the polymer particle according to claim 3,
In the solid-liquid separation step, after the crude product is charged into the pressure filter, the pressure in the pressure filter is increased to be within a range of 0.01 MPa to 0.50 MPa. A method for producing polymer particles. A method for producing polymer particles according to claim 3 or 4,
In the washing step, after the washing liquid is put into the pressure filter holding the polymer particles on the filter medium, the pressure in the pressure filter is in the range of 0.01 MPa to 0.50 MPa. A method for producing polymer particles, characterized by pressurizing as described above. A method for producing polymer particles according to any one of claims 3 to 5,
In the solid-liquid separation step, after the crude product is put into the pressure filter, the inside of the pressure filter is pressurized,
70% by weight or more of the medium passes through the filter medium with respect to 100% by weight of the medium contained in the crude product put into the pressure filter, and the pressure filter contains The method for producing polymer particles is characterized in that the solid-liquid separation step is terminated when the pressure becomes 80% or less with respect to the pressure of 100% during pressurization. It is a manufacturing method of the polymer particle according to any one of claims 3 to 6,
In the washing step, the inside of the pressure filter is pressurized after the washing liquid is put into the pressure filter holding the polymer particles on the filter medium,
The conductivity of the cleaning liquid that has passed through the filter medium is not more than 2.0 times the conductivity of the cleaning liquid before being introduced into the pressure filter, and the pressure in the pressure filter is equal to that at the time of pressurization. The method for producing polymer particles, wherein the washing step is terminated when the pressure becomes 80% or less with respect to a pressure of 100%. It is a manufacturing method of the polymer particle according to any one of claims 1 to 7,
In the cleaning step, a cleaning liquid having a weight of 15 to 38 times the weight of the polymer particles held on the filter medium is used.

Images