WO2016051814A1

WO2016051814A1 - Polymer particles, method for producing same, and use of same

Info

Publication number: WO2016051814A1
Application number: PCT/JP2015/054179
Authority: WO
Inventors: 智之 ▲高▼橋
Original assignee: 積水化成品工業株式会社
Priority date: 2014-09-30
Filing date: 2015-02-16
Publication date: 2016-04-07
Also published as: JP2020019968A; KR101729111B1; TW201617131A; CN105683227A; TWI545136B; CN110229267B; KR20160050007A; TWI577440B; JPWO2016051814A1; JP2016069621A; KR20160052791A; JP6560981B2; KR20160038718A; KR101863072B1; JP2019035097A; JP6612417B2; TW201612195A; CN110229267A; CN105683227B; KR101634940B1

Abstract

Provided are: polymer particles having excellent dispersibility and dispersion uniformity; a method for producing the polymer particles; and an optical film produced using the polymer particles. The polymer particles have a coefficient of variation in particle diameter of 15.0% or less, and each of the polymer particles contains a surfactant having a polyoxyethylene chain in an amount of 2.0 to 15.0 × 10^-3 g/m² per unit surface area thereof and also contains another surfactant in an amount of 10.0 × 10^-5 g/m² or less per unit surface area thereof.

Description

POLYMER PARTICLE, PROCESS FOR PRODUCING THE SAME, AND USE THEREOF

The present invention relates to polymer particles suitably used as a raw material for optical members such as light diffusing films and antiglare films, a method for producing the same, and uses (optical films) of the polymer particles. More specifically, the present invention relates to polymer particles containing a surfactant having a predetermined amount of polyoxyethylene chains per unit surface area of the polymer particles, a method for producing the same, and uses of the polymer particles (optical film). )

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 vinyl as a resin fine particle (polymer particle) used as a light diffusing agent in a medium containing a surfactant (in the examples, other surfactants having no polyoxyethylene chain). The amount of the surfactant obtained by polymerizing the monomer and remaining in the resin fine particles is 0.05 parts by weight or less (0.005 to 0.036 weight in the examples) with respect to 100 parts by weight of the resin fine particles. Part) is disclosed.

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. Patent Document 2 does not disclose a surfactant having a polyoxyethylene chain, and does not disclose the remaining amount of the surfactant in the washed organic particles.

Patent Document 3 discloses colored resin particles taken out from a dispersion of colored resin particles by washing as colored resin particles used as a toner for developing an electrostatic latent image. Patent Document 3 does not disclose a surfactant having a polyoxyethylene chain, and does not disclose the remaining amount of the surfactant in the washed organic particles.

Patent Document 4 discloses an electrostatic charge image developing toner containing a binder resin, a colorant, and a charge control resin having a specific repeating unit, and a remaining surfactant (polyoxyethylene chain in the examples). An electrostatic charge image developing toner is disclosed in which the amount of the other surfactant (having no surfactant) is 1 to 1000 ppm.

Patent Document 5 discloses a coating composition containing organic particles and a surfactant, wherein the surfactant content is 500 to 2000 ppm with respect to the organic particles. ing. Further, in Example 5 of Patent Document 5, the coefficient of variation is 6.2%, and polyoxyethylene distyryl phenyl ether sulfate ammonium salt (a kind of surfactant having a polyoxyethylene chain) is added from 520 to Organic particles containing 1550 ppm (0.1200%) and no other surfactants are disclosed. In Examples 2 and 4 of Patent Document 5, the coefficient of variation is 35.5 to 37.1%, and polyoxyethylene distyrylphenyl ether sulfate ammonium salt is 520 to 1550 ppm (0.0520 to 0.1550%). ) Containing organic particles that are free of other surfactants. In Example 3 of Patent Document 5, polyoxyethylene distyryl phenyl ether sulfate ammonium salt and sodium lauryl sulfate (one of other surfactants having no polyoxyethylene chain) total 1950 ppm (0 .1950%) containing organic particles are disclosed.

In Patent Document 6, an oily raw material liquid is prepared by dissolving or dispersing a raw material for a toner containing a binder resin, a colorant, a charge control agent, and a release agent in an organic solvent without performing a cleaning treatment. A method for producing toner particles is disclosed that is prepared, granulated while supplying the oily raw material liquid to a spray dryer and spray drying to form colored resin particles.

JP 2006-233305 A JP 2007-161830 A JP 2011-158889 A JP 2002-189317 A JP 2009-203378 A JP 2009-175632 A

By the way, as an optical film such as a light diffusion film or an antiglare film, there is one obtained by coating a resin composition containing polymer particles and a binder on a film substrate.

When producing such an optical film, before coating the resin composition on the film substrate so that uniform optical properties 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 a resin composition is produced by uniformly dispersing polymer particles produced using the surfactants disclosed in Patent Documents 1 to 5 in a mixture of a binder and an organic solvent, the produced resin composition In the process of coating a product on the film substrate to form a coating film, the dispersion state of the polymer particles in the resin composition may be non-uniform. For example, when the polymer film disclosed in Patent Documents 1 to 5 is used to produce the optical film, the dispersion state of the polymer particles in the resin composition is not stable, and the coating film is formed by the coating. In the process of forming the polymer particles, the dispersion state of the polymer particles in the resin composition becomes non-uniform, and the polymer particles sometimes locally aggregate excessively. As a result, the polymer particles are not spread uniformly over the entire coating film formed on the base film, the optical properties of the optical film become non-uniform, and the desired optical properties cannot be obtained over the entire optical film. there were.

The reason why the dispersion state of the polymer particles in the resin composition is unstable and the dispersion state of the polymer particles in the resin composition is uneven in the process of forming a coating film by the coating is that Since it is considered that there is a variation in the amount of surface residual components on the surface of the coalesced particles and a variation in the surface state due to this, it is desired that the amount of surface residual components on the surface of the polymer particles be constant (uniform). In order to make the amount of residual components on the surface of the polymer particles constant, components that bind strongly to the surface of the polymer particles and contribute to the modification of the surface of the polymer particles (for example, contribute to the modification of the surface of the polymer particles) It is considered that the amount of surface residual components on the surface of the polymer particles should be reduced as much as possible except for the surfactant having an amount of polyoxyethylene chains.

When using polymer particles for optical films such as light diffusion films and antiglare films, it is usually necessary to adjust the refractive index of the polymer particles to the desired refractive index, so the composition of the polymer particles is adjusted. In this way, the refractive index of the polymer particles is adjusted. When an optical film is produced using a resin composition in which polymer particles are dispersed in a mixture of a binder and an organic solvent, the solubility parameter (hereinafter referred to as “SP value”) is high depending on the composition of the polymer particles. Uniform dispersion in an organic solvent may be difficult. For example, polymer particles composed of at least one of a (meth) acrylic polymer, a styrene polymer, and a (meth) acryl-styrene copolymer have an SP value of 14.3 to 19.4 ( MPa) ^1/2 (7.0 to 9.0 (cal / cm ³ ) ^1/2 ) and an organic solvent having a high SP value (hereinafter referred to as “high SP value organic solvent”). An organic solvent that is 20.5 (MPa) ^1/2 (10 (cal / cm ³ ) ^1/2 ) or more, for example, an SP value of 24.3 (MPa) ^1/2 (11.9 (cal / cm ³ ) ^{Even if} it is attempted to disperse in isopropyl alcohol that is ^1/2 ), aggregation may become remarkable and uniform dispersion may be difficult.

As a technique for improving the dispersibility of the polymer particles in the high SP value organic solvent, a monomer having high hydrophilicity is added to the monomer used for the production of the polymer particles. It is conceivable to modify the surface of the coalesced particles. However, if a monomer having high hydrophilicity is added to the monomer used for the production of the polymer particle to give the polymer particle dispersibility in the high SP value organic solvent, the polymer particle Since its composition changes, it becomes difficult to control the refractive index.

Further, in the production method of Patent Document 6, since the colored resin particles are produced by spray drying without performing the washing treatment, the additive used in the polymerization (the other interface) Activator, dispersion stabilizer, polymerization inhibitor, etc.) or when the binder resin used in the production is a resin particle containing a by-product (emulsion polymerization product) generated during the polymerization reaction, It becomes difficult to remove other additives such as surfactants and by-products (emulsion polymerization products), which causes non-uniform dispersibility of the colored resin particles in the binder and the organic solvent.

Here, the “emulsion polymerization product” refers to a target polymer produced by emulsion polymerization in an aqueous phase, which is a side reaction, in seed polymerization for producing polymer particles having a uniform particle diameter. It means a polymer particle having a remarkably small particle diameter (for example, a particle diameter of 300 nm or less) compared to the particle diameter of the coalesced particle. In seed polymerization, polymerization is often performed in the presence of a polymerization inhibitor in order to suppress the generation of by-products (emulsion polymerization products). It is difficult to completely prevent the occurrence of polymerization products). Further, by increasing the addition amount of the polymerization inhibitor, it is possible to enhance the effect of suppressing the generation of the by-product (emulsion polymerization product), but on the other hand, the residual monomer in the resulting polymer particles The amount increases and affects the quality of the polymer particles.

As a result, the polymer particles are not spread uniformly over the entire coating film formed on the base film, the optical properties of the optical film are non-uniform, and the desired optical properties cannot be obtained over the entire optical film. was there.

Therefore, the dispersibility with respect to the high SP value organic solvent is good, and in the process of forming the coating film by coating the resin composition obtained by dispersing the polymer particles in the binder on the film substrate, a uniform dispersion state Thus, it has been desired to develop polymer particles excellent in dispersion uniformity (uniformity of dispersion state) that can impart uniform optical properties to the optical film.

The present invention has been made in view of the above situation, and aims to provide polymer particles excellent in dispersibility and dispersion uniformity, a method for producing the same, and an optical film using the polymer particles. To do.

As a result of intensive studies in view of the above problems, the present inventors have found that the surface state of the polymer particles affects the dispersibility and dispersion uniformity, and in order to improve the dispersibility and dispersion uniformity, In order to complete the present invention, it is important to attach an appropriate amount of a surfactant having a polyoxyethylene chain to the surface of the coalesced particles and to keep the content of other surfactants to a predetermined amount or less. It came.

The polymer particle of the present invention is a polymer particle containing a surfactant having a polyoxyethylene chain, the coefficient of variation of the particle diameter is 15.0% or less, and per unit surface area of the polymer particle The content of the surfactant having a polyoxyethylene chain is 2.0 to 15.0 × 10 ⁻³ g / m ² , and the other surfactant (polyoxyethylene per unit surface area of the polymer particles). The content of the surfactant other than the surfactant having a chain, that is, the surfactant having no polyoxyethylene chain) is 10.0 × 10 ⁻⁵ g / m ² or less.

In the polymer particle having the above-described configuration, the content of the surfactant having the polyoxyethylene chain per unit surface area of the polymer particle is 2.0 × 10 ⁻³ g / m ² or more, and the polyoxyethylene chain Since the hydrophilic part derived from the surfactant having an appropriate amount develops on the surface of the polymer particle (the surface of the polymer particle is modified with the hydrophilic part), the hydrophilic composition is hydrophilic in the composition of the polymer particle. Dispersibility in a high SP value organic solvent can be improved without including a hydrophilic portion derived from a highly soluble monomer.

Furthermore, the polymer particles having the above-described configuration have a coefficient of variation in particle diameter of 15.0% or less, and the content of the surfactant having the polyoxyethylene chain per unit surface area of the polymer particles is 15.0. × 10 ⁻³ g / m ² or less, and the content of other surfactants per unit surface area of the polymer particles is suppressed to 10.0 × 10 ⁻⁵ g / m ² or less. As a result, there is little difference in the surface state between the polymer particles, so that when used in a mixture with a binder, the dispersion uniformity in the binder is excellent. In particular, the polymer particles having the above-described structure have a content of the surfactant having the polyoxyethylene chain per unit surface area of the polymer particles of 2.0 × 10 ⁻³ g / m ² or more as described above. As a result, the dispersibility in the high SP value organic solvent is improved, so there is no variation in the dispersion in the high SP value organic solvent, and the dispersion is uniform in the mixture of the high SP value organic solvent and the binder. The state can be formed, and the dispersion uniformity is excellent. Further, when the resin composition obtained by dispersing the polymer particles having the above constitution in a binder (particularly in a mixture of a high SP value organic solvent and a binder) is coated on a film substrate, The uniform dispersion state of the polymer particles in the resin composition is maintained almost stably in the process of forming the coating film by the coating, 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 uniform light diffusibility and antiglare property to the entire coating film formed by the coating.

In addition, since the polymer particle having the above configuration has a coefficient of variation of the particle diameter of 15.0% or less, when the polymer particle is used for an optical member such as an antiglare film or a light diffusion film, the prevention of the optical member is prevented. Optical properties such as glare and light diffusibility can be improved.

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

The optical film of the present invention is formed by applying the coating resin composition containing the polymer particles of the present invention excellent in dispersibility and dispersion uniformity on a base material, and thus formed by the coating. In the entire coating film, uniform optical properties such as uniform light diffusibility and antiglare properties can be obtained.

The method for producing polymer particles includes a polymerization step, and further includes a solid-liquid separation step, a washing step, a drying step, and a classification step as necessary. The processes that can affect the uniformity of the amount of residual components on the surface of the polymer particles and the uniformity of the surface condition caused thereby are the solid-liquid separation process and the washing process, and these processes become unstable. In other words, the unnecessary part of the surfactant used for the production of the polymer particles (a surfactant having an excess polyoxyethylene chain that does not contribute to the modification of the polymer particle surface, and other used as necessary) Surfactant) and a polymer dispersion stabilizer used as necessary, adversely affecting the amount of residual components on the surface of the polymer particles. Therefore, the inventor of the present application adjusts the amount per unit time of the medium that has passed through the filter medium in the solid-liquid separation step and the washing step and the amount of the washing solution in the washing step within a predetermined range, thereby achieving dispersion uniformity. The inventors have found that polymer particles having excellent dispersibility can be produced by modifying the surface with a surfactant having a polyoxyethylene chain, and have completed 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 containing a surfactant having a polyoxyethylene chain, and the polyoxyethylene chain is polymerized. A polymerization step for obtaining a crude product containing the polymer particles containing the surfactant having the above-mentioned medium and the medium, the crude product is charged into a filter, and the medium contained in the charged crude product is filtered into the filter A solid-liquid separation step of allowing the polymer particles contained in the crude product to be retained on the filter medium while passing the filter medium through the filter medium, and supplying the cleaning liquid to the filter holding the polymer particles on the filter medium, A cleaning step of bringing the cleaning liquid in contact with the polymer particles and passing the cleaning liquid in contact with the polymer particles through the filter medium to obtain polymer particles cleaned with the cleaning liquid on the filter medium. The solid-liquid content In step, the amount per unit time of the medium which has passed through the filter media, the following conditional expressions (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):
2.50 × A ≦ 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 of 9 to 18 times 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 9 to 18 times the weight of the polymer particles held on the filter medium is used. Therefore, the polymer adhering to the polymer particles in the polymerization step is used. An appropriate amount of a surfactant (which does not contribute to the modification of the polymer particle surface) containing a surfactant having an oxyethylene chain (with an excess polyoxyethylene chain that does not contribute to the modification of the polymer particle surface) together with the medium and the cleaning liquid The amount of surfactant) can be removed. Furthermore, when polymerization is carried out in the presence of a surfactant containing both a surfactant having a polyoxyethylene chain and another surfactant, most of the other surfactant is sufficiently removed together with the medium and the cleaning liquid. can do. As a result, the content (residual amount) of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is an appropriate amount (2.0 to 15.0 × 10 ⁻³ g / m ² ), Polymer with excellent dispersibility and dispersion uniformity with a very small content (residual amount) of other surfactants per unit surface area of the coalesced particles (10.0 × 10 ⁻⁵ g / m ² or less) Particles can be obtained.

When producing polymer particles composed of at least one of a (meth) acrylic polymer, a styrene polymer, and a (meth) acryl-styrene copolymer by the above production method, The activator is almost removed by washing (the content of other surfactant per unit surface area of the polymer particles is 10.0 × 10 ⁻⁵ g / m ² or less), whereas polyoxyethylene The surfactant having a chain is not easily removed by washing, and remains on the surface of the polymer particle at a level of 2.0 to 15.0 × 10 ⁻³ g / m ² per unit surface area of the polymer particle. It has been confirmed that it covers the surface of polymer particles. This is because the surfactant having a polyoxyethylene chain has an SP value of the polyoxyethylene chain of 14.3 to 19.4 (MPa) ^1/2 (7.0 to 9.0 (cal / cm ³ ) ^{1 / 2} ), and the SP value of (meth) acrylic polymer, styrene polymer, and (meth) acrylic-styrene copolymer (14.3 to 19.4 (MPa) ^1/2 (7. 0 to 9.0 (cal / cm ³ ) ^1/2 )), it is presumed that this is due to the strong connection with the polymer particles and difficulty in removal with water or hot water.

According to the present invention, polymer particles excellent in dispersibility and dispersion uniformity, a method for producing the same, and an optical film using the polymer particles 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. 2 is a view showing an SEM (scanning electron microscope) image of the polymer particles obtained in Example 1. FIG. FIG. 3 is a view showing an SEM image of polymer particles obtained after the solid-liquid separation step and the washing step in Example 1.

Hereinafter, the present invention will be described in detail.

(Polymer particles)
The polymer particle of the present invention is a polymer particle containing a surfactant having a polyoxyethylene chain, the coefficient of variation of the particle diameter is 15.0% or less, and per unit surface area of the polymer particle The content of the surfactant having a polyoxyethylene chain is 2.0 to 15.0 × 10 ⁻³ g / m ² , and the content of the other surfactant per unit surface area of the polymer particle is 10.0 × 10 ⁻⁵ g / m ² or less.

As described above, the polymer particles having the above structure are dispersed in a high SP value organic solvent without including a hydrophilic part derived from a highly hydrophilic monomer in the composition of the polymer constituting the polymer particles. Can be improved. Furthermore, as described above, the polymer particles having the above-described structure are used by being mixed with a binder (particularly, a mixture of a high SP value organic solvent and a binder) because there is little difference in the surface state between the polymer particles. In some cases, the dispersion uniformity is excellent in the binder (particularly in a mixture of a high SP value organic solvent and a binder). Further, the polymer particles having the above-described structure are excellent in quality stability because the temporal change in the surface state of the polymer particles and the difference in the surface state between production lots of the polymer particles are small. As a result, when the polymer particles having the above constitution are dispersed in a binder and used as a resin composition, the dispersion state difference between production lots of the resin composition is small, and the dispersion stability is excellent.

The polymer particles having the above structure are prepared by adding 15.0 g of water to 5.0 g of the polymer particles and dispersing the polymer particles in water by performing a dispersion treatment for 60 minutes using an ultrasonic cleaner. After centrifuging in a centrifuge tube under conditions of K-factor 6943 and rotation time of 30 minutes using a centrifuge, when the supernatant liquid is recovered, the non-volatile components in the supernatant liquid (polymer particles are produced by seed polymerization). In the case of a manufactured product, the concentration of the by-product (equivalent to an emulsion polymerization product) is preferably less than 1.0% by weight, more preferably less than 0.5% by weight, More preferably, it is less than 0.3% by weight. Thereby, since the difference in the amount of by-products (emulsion polymerization product) and the like existing on the surfaces of the polymer particles can be reduced, the polymer particles are bonded to the binder (particularly, the high SP value organic solvent and the binder). When the mixture is used as a mixture, the dispersion uniformity of the polymer particles in the binder (particularly in the mixture of the high SP value organic solvent and the binder) can be further improved.

The content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is more preferably 3.0 to 15.0 × 10 ⁻³ g / m ² . Thereby, the dispersibility with respect to the high SP value effective solvent of the said polymer particle can further be improved. Further, the content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is more preferably 4.0 to 15.0 × 10 ⁻³ g / m ² . Thereby, the dispersion uniformity of the polymer particles can be further improved.

The content of the other surfactant per unit surface area of the polymer particles is more preferably 7.0 × 10 ⁻⁵ g / m ² or less, and 5.0 × 10 ⁻⁵ g / m ² or less. More preferably, it is 3.0 × 10 ⁻⁵ g / m ² or less. Thereby, the dispersion uniformity of the polymer particles can be further improved.

The coefficient of variation of the particle diameter of the polymer particles is more preferably 12.0% or less, and further preferably 10.0% or less. Thereby, the dispersion uniformity of the polymer particles can be further improved.

The content of the surfactant having a polyoxyethylene chain and other surfactants in the polymer particles is measured by, for example, liquid chromatography / mass spectrometry (LC-MS-MS). It can be calculated by dividing the content of the surfactant having a polyoxyethylene chain and the other surfactant by the specific surface area of the polymer particles measured using the BET method (nitrogen adsorption method), respectively. .

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, having a polyoxyethylene chain as described in the section of [Method for producing polymer particles] described later. An anionic surfactant, a nonionic surfactant having a polyoxyethylene chain, a cationic surfactant having a polyoxyethylene chain, and an amphoteric surfactant having a polyoxyethylene chain can be mentioned. The surfactant contained in the polymer particles of the present invention preferably contains at least one of an anionic surfactant and a nonionic surfactant, and more preferably contains an anionic surfactant. When the polymer particles of the present invention contain an anionic surfactant, the dispersion stability during the polymerization reaction can be ensured. On the other hand, when the surfactant contained in the polymer particles of the present invention is only a nonionic surfactant, only the nonionic surfactant is present during the polymerization reaction, and significant aggregation occurs during the polymerization reaction. There is a case.

The surfactant having a polyoxyethylene chain contained in the polymer particle of the present invention contains at least one of an anionic surfactant having a polyoxyethylene chain and a nonionic surfactant having a polyoxyethylene chain. It is preferable to include an anionic surfactant having a polyoxyethylene chain. When the polymer particles of the present invention contain an anionic surfactant having a polyoxyethylene chain, the dispersion stability during the polymerization reaction can be ensured. On the other hand, when the surfactant having a polyoxyethylene chain contained in the polymer particles of the present invention is only a nonionic surfactant having a polyoxyethylene chain, it has a polyoxyethylene chain present during the polymerization reaction. Only the nonionic surfactant in which the surfactant has a polyoxyethylene chain is present, and significant aggregation may occur during the polymerization reaction.

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 of 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) acrylate monomer include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isononyl acrylate, 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; dimethyl Amino ethyl 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 particles are preferably composed of at least one of a (meth) acrylic polymer, a styrene polymer, and a (meth) acryl-styrene copolymer. 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. Among these, the polymer particles are preferably composed of a (meth) acryl-styrene copolymer from the viewpoint of light diffusibility and antiglare property.

The polymer constituting the polymer particles is preferably a copolymer (crosslinked polymer) of the monofunctional vinyl monomer and the polyfunctional vinyl monomer. Therefore, the polymer constituting the polymer particles is particularly preferably a (meth) acryl-styrene cross-linked copolymer from the viewpoint of light diffusibility and antiglare property. 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 refractive index of the polymer particles of the present invention is preferably 1.490 to 1.600. As a result, the polymer particles having the above-described structure exhibit good optical characteristics (for example, light transmittance, antiglare property, light diffusibility, etc.) when used for an optical member such as an antiglare film or a light diffusion film. The optical member which has can be implement | achieved. In addition, polymer particles produced by adding a highly hydrophilic monomer to a monomer having a high refractive index of a homopolymer (for example, a styrene monomer) have a highly hydrophilic monomer. Since the refractive index of a homopolymer is generally low (for example, 1.488 or less), the refractive index is lower than that of polymer particles produced without adding a highly hydrophilic monomer. Therefore, it is difficult to realize polymer particles having a refractive index of 1.570 to 1.600 with such a polymer particle. In contrast, the polymer particles of the present invention do not require the addition of a highly hydrophilic monomer, so that polymer particles having a refractive index of 1.570 to 1.600 can be easily realized.

The volume average particle diameter of the polymer particles is preferably 0.5 to 100 μm, 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 polymer particles are preferably obtained by polymerization in the presence of a surfactant, particularly in the presence of a surfactant containing a surfactant having a polyoxyethylene chain. Obtained by absorbing the monomer into seed particles and polymerizing (ie, seed polymerizing) in the presence of a surfactant, particularly in the presence of a surfactant comprising a surfactant having a polyoxyethylene chain. More preferably. 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 containing a surfactant having a polyoxyethylene chain, and the polyoxyethylene chain is polymerized. A polymerization step for obtaining a crude product containing the polymer particles containing the surfactant having the above-mentioned medium and the medium, the crude product is charged into a filter, and the medium contained in the charged crude product is filtered into the filter A solid-liquid separation step of allowing the polymer particles contained in the crude product to be retained on the filter medium while passing the filter medium through the filter medium, and supplying the cleaning liquid to the filter holding the polymer particles on the filter medium, A cleaning step of 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 to obtain polymer particles cleaned with the cleaning liquid on the filter medium. . The production method of the present invention is suitable as a method for producing the above-described polymer particles of the present invention.

Hereinafter, each step of the production method of the present invention will be described in detail.

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

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. Examples of the surfactant having a polyoxyethylene chain include an anionic surfactant having a polyoxyethylene chain, a cationic surfactant having a polyoxyethylene chain, a nonionic surfactant having a polyoxyethylene chain, and Any of the zwitterionic surfactants having a polyoxyethylene chain can be used, but in the polymerization step, the dispersion of the vinyl monomer in the liquid medium can be more stably ensured, Since polymer particles having a uniform particle diameter can be obtained, it is preferable to use at least one of an anionic surfactant having a polyoxyethylene chain and a nonionic surfactant having a polyoxyethylene chain. It is more preferable to use at least an anionic surfactant having a polyoxyethylene chain as the surfactant having a polyoxyethylene chain. Thereby, the dispersion stability at the time of a polymerization reaction is securable. On the other hand, when only the nonionic surfactant having a polyoxyethylene chain is used as the surfactant having a polyoxyethylene chain, significant aggregation may occur during the polymerization reaction.

Examples of the anionic surfactant having a polyoxyethylene chain include known anionic surfactants such as fatty acid salt type, sulfate ester type, sulfonate salt type, phosphate ester salt type, and phosphate ester type. For example, polyoxyethylene alkyl phenyl ether sulfate ester salt; polyoxyethylene alkyl ether sulfate salt such as sodium polyoxyethylene lauryl ether sulfate; polyoxyethylene alkyl sulfate ester; polyoxyethylene styrenated phenyl ether sulfate ester Polyoxyethylene styrenated phenyl ether sulfate such as ammonium; polyoxyethylene such as polyoxyethylene nonylphenyl ether phosphate (for example, sodium polyoxyethylene nonylphenyl ether phosphate) Emissions alkyl phenyl ether phosphates; polyoxyethylene styrenated phenyl ether phosphate, polyoxyethylene alkyl ether phosphate and the like. One kind of these anionic surfactants having a polyoxyethylene chain may be used alone, or two or more kinds may be used in combination.

As the nonionic surfactant having a polyoxyethylene chain, any known nonionic surfactant such as an ester type, an ether type, and an ester / ether type can be used. For example, polyoxyethylene tridecyl ether Polyoxyethylene alkyl ethers such as polyoxyethylene alkyl phenyl ethers such as polyoxyethylene octyl phenyl ether, polyoxyethylene styrenated phenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acids such as polyoxyethylene sorbitan monolaurate Examples thereof include esters, polyoxyethylene alkylamines, and oxyethylene-oxypropylene block polymers. One of these nonionic surfactants having a polyoxyethylene chain may be used alone, or two or more thereof may be used in combination.

The surfactant having a polyoxyethylene chain may be used alone or in combination of two or more. The surfactant having a polyoxyethylene chain 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, preferably 0.5 g / 100 ml to 3.0 g / 100 ml. Are more preferred. When a surfactant having a polyoxyethylene chain having a solubility of less than 0.3 g / 100 ml is used, in the polymerization step, when the liquid medium is an aqueous medium, a vinyl monomer in the aqueous medium is used. May not be stably dispersed, and it is difficult to elute the surfactant into water. Therefore, a large amount of washing liquid is required in the washing step described later for washing the polymer particles. It is not preferable. On the other hand, the surfactant having a polyoxyethylene chain 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 the surfactant having the polyoxyethylene chain is used, in the polymerization step, when the liquid medium is an aqueous medium, the dispersion of the vinyl monomer in the aqueous medium is stabilized. In addition, a surfactant having a large amount of polyoxyethylene chain is required, which is not preferable in terms of productivity.

The surfactant may contain another surfactant (a surfactant other than a surfactant having a polyoxyethylene chain, that is, a surfactant having no polyoxyethylene chain). Examples of the other surfactants include an anionic surfactant having no polyoxyethylene chain, a cationic surfactant having no polyoxyethylene chain, a nonionic surfactant having no polyoxyethylene chain, and a polyoxyethylene chain. Any of the zwitterionic surfactants having no oxyethylene chain can be used, but in the polymerization step, the dispersion of the vinyl monomer in the liquid medium can be more stably ensured, Since polymer particles having a uniform particle size can be obtained, it is preferable to use at least one of an anionic surfactant having no polyoxyethylene chain and a nonionic surfactant having no polyoxyethylene chain. It is more preferable to use at least an anionic surfactant as the surfactant. Thereby, the dispersion stability at the time of a polymerization reaction is securable. On the other hand, when only a nonionic surfactant is used as the surfactant, significant aggregation may occur during the polymerization reaction.

As the anionic surfactant having no polyoxyethylene chain, any known anionic surfactant such as fatty acid salt type, sulfate ester type, sulfonate salt type, and phosphate ester salt type can be used. Fatty acid soaps such as sodium oleate and castor oil potash soap; alkyl sulfate esters such as lauryl sulfate (eg sodium lauryl sulfate, ammonium lauryl sulfate); alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; alkyl Dialkylsulfosuccinates such as naphthalenesulfonate, alkanesulfonate, di (2-ethylhexyl) sulfosuccinate (sodium salt), dioctylsulfosuccinate (sodium salt); alkenyl succinate (dipotassium salt); Acid Este Salts; naphthalenesulfonic acid-formalin condensates and the like. These anionic surfactants having no polyoxyethylene chain may be used alone or in combination of two or more.

As the nonionic surfactant having no polyoxyethylene chain, any known nonionic surfactant such as an ester type, an ether type, an ester / ether type, and the like can be used. For example, the carbon number of an alkylene group And polyoxyalkylene alkyl ethers such as polyoxyalkylene tridecyl ether having 3 or more, sorbitan fatty acid ester, glycerin fatty acid ester and the like. These nonionic surfactants having no polyoxyethylene chain may be used alone or in combination of two or more.

As the cationic surfactant having no polyoxyethylene chain, any known cationic surfactants such as amine salt type and quaternary ammonium salt type can be used. An activator is advantageous for its handling. Specific examples of the cationic surfactant having no polyoxyethylene chain include alkylamine salts such as laurylamine acetate and stearylamine acetate; lauryltrimethylammonium chloride, hexadecyltrimethylammonium chloride, cocoyltrimethylammonium chloride, dodecyltrimethyl. Examples thereof include alkyltrimethylammonium chlorides such as ammonium chloride; alkyldimethylbenzyl chlorides such as hexadecyldimethylbenzylammonium chloride and lauryldimethylbenzylammonium chloride. One of these cationic surfactants having no polyoxyethylene chain may be used alone, or two or more thereof may be used in combination.

Examples of the zwitterionic surfactant having no polyoxyethylene chain include lauryl dimethylamine oxide, phosphate ester surfactants, phosphite ester surfactants, and the like. These amphoteric surfactants not having a polyoxyethylene chain may be used alone or in combination of two or more.

The surfactant having no polyoxyethylene chain may be used alone or in combination of two or more. The surfactant having no polyoxyethylene chain preferably has a solubility in water at a liquid temperature of 25 ° C. of 0.3 g / 100 ml to 15.0 g / 100 ml, preferably 0.5 g / 100 ml to 5.0 g. / 100ml is more preferable. When a surfactant having no polyoxyethylene chain having a solubility of less than 0.3 g / 100 ml is used, when the liquid medium is an aqueous medium in the polymerization step, a vinyl monomer in the aqueous medium is used. The body may not be stably dispersed, and it is difficult to elute the surfactant into water. Therefore, a large amount of washing liquid is required in the washing step described below for washing the polymer particles. It is not preferable in terms of surface. On the other hand, the surfactant having a polyoxyethylene chain having a solubility exceeding 15.0 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. Therefore, when a surfactant having no polyoxyethylene chain is used, in the polymerization step, when the liquid medium is an aqueous medium, the dispersion of the vinyl monomer in the aqueous medium is stabilized. Therefore, a large amount of a surfactant having no polyoxyethylene chain is required, which is not preferable in terms of productivity.

Amount of surfactant used in the polymerization of the above vinyl monomer (when only an anionic surfactant having no polyoxyethylene chain is used as the surfactant, an anionic surfactant having no polyoxyethylene chain is used. The amount of the agent used, and when using an anionic surfactant having no polyoxyethylene chain and another surfactant as the surfactant, the amount of the anionic surfactant having no polyoxyethylene chain The total amount of other surfactants used is preferably in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the vinyl monomer used. 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 polymerization of a vinyl monomer, seed (seed) particles made of a polymer of a vinyl monomer prepared separately 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 seed polymerization is the most preferable polymerization method for the vinyl monomer, in the production method of the present invention, the polymerization step includes an interface having seed particles and polyoxyethylene chains in a liquid medium. A vinyl monomer is seed-polymerized in the presence of a surfactant containing an activator to obtain a crude product containing the polymer particles containing the surfactant having the polyoxyethylene chain and the medium. It is preferable to include.

Hereinafter, a general method of seed polymerization will be described, 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 containing a surfactant having a polyoxyethylene chain. The emulsion can be prepared by a known method. For example, a vinyl monomer and a surfactant containing a surfactant having a polyoxyethylene chain are added to an aqueous medium and dispersed by a fine emulsifier such as a homogenizer, an ultrasonic processor, or a nanomizer (registered trademark). Thus, an emulsion can be obtained. 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. In order to promote the absorption of the vinyl monomer into the seed particles, the emulsion may be heated to about 30 to 50 ° C.

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 50 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 independently suspended and polymerized in an aqueous medium, resulting in abnormal particles that are not intended. Diameter 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.

The polymerization initiator is not particularly limited. For example, benzoyl peroxide, lauroyl peroxide, benzoyl peroxide, o-methoxybenzoyl 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-carbonite) ), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), (2-carbamoylazo) isobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), dimethyl-2 Azo compounds such as 2,2′-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.

In order to suppress the occurrence of emulsion polymerization products (polymer particles having a particle size too small) in the aqueous medium in the polymerization reaction, nitrites such as sodium nitrite, sulfites, hydroquinones, ascorbic acids, Water-soluble polymerization inhibitors such as water-soluble 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, 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 per unit time of the medium that has passed through the filter medium so as to satisfy the conditional expression (1), the polymerization reaction is included in the crude product together with the medium. Of the by-product (emulsion polymerization product) generated in the surface, the surfactant having an excess polyoxyethylene chain that does not contribute to the modification of the polymer particle surface among the surfactant having a polyoxyethylene chain used as necessary Activators, other surfactants used as necessary, polymer dispersion stabilizers used as necessary, and unnecessary components such as polymerization additives (eg, polymerization inhibitors) used as necessary The amount of the unnecessary component remaining in the polymer particles remaining on the filter medium (specifically, the amount of adhesion to 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, 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. 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). Of the by-product (emulsion polymerization product) generated during the polymerization reaction attached to the surface of the polymer particles remaining on the filter medium 3, and the surfactant having a polyoxyethylene chain used as necessary. Among them, surfactants with excess polyoxyethylene chains that do not contribute to the modification of the polymer particle surface, other surfactants used as necessary, polymer dispersion stabilizers used as necessary, necessary Accordingly, unnecessary components such as a polymerization additive (for example, a polymerization inhibitor) used depending on the temperature can be sufficiently removed together with the medium, and the residual amount of the unnecessary components in the polymer particles can be reduced. When the amount (discharge amount) of the medium passed through the filter medium 3 in the solid-liquid separation step is less than 70% by weight with respect to 100% by weight of the medium contained in the crude product P, during the polymerization reaction Of the generated by-products (emulsion polymerization products) and surfactants having polyoxyethylene chains used as necessary, surfactants having surplus polyoxyethylene chains that do not contribute to the modification of the polymer particle surface Unnecessary components such as other agents, other surfactants used as needed, polymer dispersion stabilizers used as needed, and polymerization additives (eg polymerization inhibitors) used as needed May not be able to be removed.

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 the pressure vessel 2 is preferably terminated when the internal pressure of the pressure vessel 2 becomes 2/3 or less of the pressure at the time of pressurization. As a result, among the by-products (emulsion polymerization product) generated during the polymerization reaction in the polymer particles remaining on the filter medium 3 and the surfactant having a polyoxyethylene chain used as necessary, Surfactant having an excess polyoxyethylene chain that does not contribute to the modification of the coalesced particle surface, other surfactant used as needed, polymer dispersion stabilizer used as needed, if necessary The residual amount of unnecessary components such as polymerization additives (for example, polymerization inhibitors) used can be reliably 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):
2.50 × A ≦ 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). If the amount Y of the cleaning liquid that has passed through the filter medium is less than 2.50 × A, the cleaning process takes too much time and the productivity may be lowered. When the amount Y of the cleaning liquid that has passed through the filter medium is larger than 8.50 × A, the time for which the polymer particles are in contact with the cleaning liquid is short, so that it adheres to the surface of the polymer particles. Of the surfactants having polyoxyethylene chains used as necessary, by-products (emulsion polymerization products) generated during the polymerization reaction, surplus polyoxy which does not contribute to the modification of the polymer particle surface Surfactant having ethylene chain, other surfactant used as necessary, polymer dispersion stabilizer used as necessary, polymerization additive used as necessary (for example, polymerization inhibitor) Such unnecessary components may not be sufficiently removed, and a large amount of the unnecessary components 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) on average, it efficiently adheres to the surface of the polymer particles and is generated during the polymerization reaction. By-product (emulsion polymerization product), a surfactant having an excess polyoxyethylene chain that does not contribute to the modification of the polymer particle surface among the surfactant having a polyoxyethylene chain used as necessary , Other surfactants used as needed, polymer dispersion stabilizers used as needed, and unnecessary components such as polymerization additives (eg polymerization inhibitors) used as needed By removing, the residual amount of the unnecessary component 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, it is preferable to pressurize the pressure vessel 2 so that the internal pressure is in the range of 0.01 MPa to 0.50 MPa. The upper space S of the filter medium 3 is preferably pressurized at a rate 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 (solid-liquid separation step) regardless of whether or not at least one other surfactant is used in the polymerization step. When all the crude products obtained in the polymerization step are put into a filter, the total amount of vinyl monomers used in the polymerization step is 9 to 18 times. When the weight of the cleaning liquid used in the cleaning step is less than 9 times the weight of the polymer particles held on the filter medium 3, a by-product generated during the polymerization reaction (emulsion polymerization generation) contained in the polymer particles Product), a surfactant having an excess polyoxyethylene chain that does not contribute to the modification of the surface of the polymer particles among the surfactant having a polyoxyethylene chain, which is used as necessary, is used as necessary Removal of unnecessary components such as other surfactants, polymer dispersion stabilizers used as necessary, polymerization additives used as necessary (for example, polymerization inhibitors) is insufficient, and the desired polymer There is a possibility that particles (particularly polymer particles in which the content of other surfactant per unit surface area of the polymer particles is 10.0 × 10 ⁻⁵ g / m ² or less) cannot be obtained. Since the weight of the washing liquid used in the washing step is 18 times or less of the weight of the polymer particles held on the filter medium 3, a portion that is not excessive in the washing step (a portion that contributes to the modification of the polymer particle surface) The surfactant having the polyoxyethylene chain is prevented from eluting, and the content of the surfactant having the polyoxyethylene chain per unit surface area of the polymer particles is 2.0 g / m ² or more. Certain polymer particles can be obtained reliably. Therefore, it is possible to reliably obtain polymer particles excellent in dispersibility in a high SP value organic solvent.

Moreover, when using at least 1 type of other surfactant in the said superposition | polymerization process, the weight B (kg) of the washing | cleaning liquid used at the washing | cleaning process is the following for every kind of other surfactant used in the said superposition | polymerization process. the total amount .SIGMA.B L calculation expression (4) lower limit of the weight of the cleaning liquid is calculated by B _{L (kg)} _(equivalent to B _L in the case of using one kind of other surfactants in the polymerization step) (kg ) And the total amount ΣB _H of the upper limit value B _H (kg) of the weight of the cleaning liquid calculated by the following calculation formula (5) for each type of other surfactant used in the polymerization step (above the polymerization step) In the case of using one type of other surfactants, it is preferably equal to or less than _BH ). That is, the weight B (kg) of the cleaning liquid used in the cleaning process preferably satisfies the following inequality (6). When one type of other surfactant is used in the polymerization step, the following inequality (6) becomes the following inequality (7).

B _L = (C ÷ D) × 1.8 (4)
B _H = (C ÷ D) × 2.3 (5)
ΣB _L ≦ B ≦ ΣB _H (6)
B _L ≦ B ≦ B _H (7)
(In the formulas (4) and (5), C represents the amount (g) of one type of other surfactant used, and D represents the one type of other surfactant with respect to the cleaning liquid having a liquid temperature of 25 ° C.) Represents solubility (g / 100 ml)

The weight of the cleaning liquid used in the cleaning process is the total amount ΣB _L (the lower limit value B _L (kg) of the cleaning liquid weight calculated by the above calculation formula (4) for each type of other surfactant used in the polymerization process. kg) or more, a by-product (emulsion polymerization product) generated during the polymerization reaction adhered to the surface of the polymer particles in the polymer particles, and the polyoxyethylene chains used as necessary. Among the surfactants possessed, surfactants having excess polyoxyethylene chains that do not contribute to the modification of the polymer particle surface, other surfactants used as necessary, polymers used as needed The content of unnecessary components such as dispersion stabilizers and polymerization additives (eg, polymerization inhibitors) used as necessary can be further reduced. When polymerization is performed in the presence of a surfactant having both a surfactant having a polyoxyethylene chain and another surfactant, the weight of the cleaning liquid used in the cleaning step is the same as that of the other surfactant used in the polymerization step. When the total amount ΣB _H (kg) of the upper limit value B _H (kg) of the weight of the cleaning liquid calculated by the above calculation formula (5) for each type of agent is exceeded, it contributes to the modification of the polymer particle surface. The surfactant having a polyoxyethylene chain is also gradually eluted, and the amount of modification by the surfactant having a polyoxyethylene chain on the surface of the polymer particles becomes uneven.

Further, the temperature of the cleaning liquid used for cleaning is preferably a temperature at which the surfactant having a polyoxyethylene chain and other surfactants are sufficiently eluted, for example, preferably 40 to 80 ° C., 50 More preferably, it is ˜80 ° C. 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 becomes 2/3 or less of the pressurizing pressure. 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), Polymer particles among the by-products (emulsion polymerization products) generated during the polymerization reaction, and surfactants having polyoxyethylene chains used as necessary, contained in the finally obtained polymer particles Surfactant with excess polyoxyethylene chain that does not contribute to surface modification, other surfactant used as needed, polymer dispersion stabilizer used as needed, used as needed The residual amount of unnecessary components such as polymerization additives (for example, polymerization inhibitors) can be reliably reduced. In addition, the amount of water that can be absorbed by the polymer particles is reduced 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 2/3 or less of the pressure at the time of pressurization. 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. In the polymerization step, the amount per hit satisfies the conditional expression (2), and in the washing step, a washing liquid having a weight of 9 to 18 times the weight of the polymer particles held on the filter medium is used. A suitable amount of surfactant (which does not contribute to the modification of the polymer particle surface) containing a surfactant having a polyoxyethylene chain attached to the polymer particle (with no medium or cleaning solution) that does not contribute to the modification of the polymer particle surface The amount of the surfactant having a polyoxyethylene chain) can be removed. Furthermore, when polymerization is carried out in the presence of a surfactant containing both a surfactant having a polyoxyethylene chain and another surfactant, most of the other surfactant is sufficiently removed together with the medium and the cleaning liquid. can do. As a result, the content (residual amount) of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is an appropriate amount (particularly 2.0 to 15.0 × 10 ⁻³ g / m ² ), The content (remaining amount) of other surfactants per unit surface area of the polymer particles is extremely small (especially 10.0 × 10 ⁻⁵ g / m ² or less), and the dispersibility and dispersion uniformity are excellent. Polymer particles can be obtained.

Further, according to the above production method, a by-product (emulsion polymerization product) generated during the polymerization reaction, a polymer dispersion stabilizer used as necessary, and a polymerization additive used as necessary (for example, Unnecessary components such as polymerization inhibitors are also removed in large amounts in the solid-liquid separation step and the washing step. For this reason, the polymer particle obtained by the said manufacturing method can also become a thing with few quantity of these unnecessary components.

[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.

The binder resin is preferably a curable resin capable of forming a crosslinked structure by a crosslinking reaction from the viewpoint of improving the durability of the coating resin composition. 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-cyclohexane tri (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. . 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 above 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-A No. 2001-139663), 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. Examples include phenone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone. 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”, and trade name “Irgacure (registered trademark) 907” (2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) manufactured by BASF Japan Ltd. ) -1-propanone) and the like.

The amount of the photopolymerization initiator used is usually in the range of 0.5 to 20% by weight, preferably in the range of 1 to 5% by weight with respect to 100% by weight of the binder.

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, a rubber binder such as synthetic rubber or natural rubber, an inorganic binder, or 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 and 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.

Since the polymer particles of the present invention are excellent in dispersibility in an organic solvent having a high SP value, a coating resin composition containing the polymer particles of the present invention, a binder and an organic solvent is applied onto a film substrate. Thus, when the optical film of the present invention is produced, the effect is remarkable. Specific examples of the high SP value organic solvent include, for example, isopropyl having an SP value calculated by the Fedors method of 24.3 (MPa) ^1/2 (11.9 (cal / cm ³ ) ^1/2 ). Alcohol, methyl alcohol having an SP value of 28.2 (MPa) ^1/2 (13.8 (cal / cm ³ ) ^1/2 ), SP value of 26.2 (MPa) ^1/2 (12.6 ( cal ^/ cm ³⁾ such as ethyl alcohol which is ^1/2), SP value and organic solvent is ^{20.5 (MPa) 1/2 (10 (} cal / cm 3) 1/2) or higher . In this specification, “SP value” refers to a solubility parameter calculated by the Fedors method.

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. Further, a film in which an easy-adhesion layer such as (meth) acrylic resin, copolymerized polyester resin, polyurethane resin, styrene-maleic acid grafted polyester resin, acrylic grafted polyester resin, etc. is further provided on these films is also used as the film substrate. Can be used.

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

In addition, an additive may be added to the film substrate. 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 on the film substrate by bar coating, blade coating, spin coating, reverse coating, die coating, 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 rays include ultraviolet rays emitted from light sources such as xenon lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, carbon arc lamps, tungsten lamps, etc .; 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 μm, more preferably in the range of 3 to 7 μm.

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

[Resin molding]
The polymer particles of the present invention can also be used for resin moldings. The resin molded body is formed by molding a molding resin composition containing the polymer particles of the present invention and a transparent resin. In the resin molded body, the polymer particles function as light diffusing particles. Therefore, the resin molded body functions as a light diffusing body such as a light diffusing plate and can be used as an LED illumination 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 co-polymerized. Polymer) and the like. Among them, 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, preferably 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 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 is formed by molding a molding resin composition containing the polymer particles of the present invention having excellent dispersion uniformity, the resin molded body has uniform light diffusibility and Optical properties such as antiglare properties 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 Of the amount per unit time (kg / min)), the method for measuring the content of the surfactant in the polymer particles, the method for calculating the content of the surfactant per unit surface area of the polymer particles, Method for measuring content of by-product (emulsion polymerization product) in coalesced particles, method for measuring gel fraction of polymer particles, method for measuring refractive index of polymer particles, weight in high SP value organic solvent Evaluation method and dispersibility of coalesced particles The method for measuring the solubility of one other surfactant to the liquid temperature 25 ° C. of the cleaning liquid will be described.

[Measurement method of volume average particle diameter of polymer particles and coefficient of variation of particle diameter]
The volume average particle diameter of the polymer particles is measured with a Coulter Multisizer ^™ 3 (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 aperture used for the measurement is appropriately selected depending on the size of the polymer particles to be measured. Current (aperture current) and Gain (gain) are appropriately set according to the size of the selected aperture. For example, when an aperture having a size of 50 μm is selected, the current (aperture current) is set to −800 and the gain (gain) is set to 4.

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 Creer) and used as a dispersion. 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 based on volume / volume average particle diameter of polymer particles) × 100

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

Specifically, 0.1 g of a slurry containing seed particles is placed in 10 ml of a 0.1 wt% nonionic surfactant aqueous solution, touch mixer (manufactured by Yamato Kagaku Co., Ltd., “TOUCHMIXER MT-31”) and ultrasonic cleaner. (Velvo Crea Co., Ltd., “ULTRASONIC CLEANER VS-150”) is used as a dispersion liquid.

The measurement is performed in a state where the seed particles are dispersed by performing pump circulation in the universal liquid sample module, and in a state where the ultrasonic unit (ULM ULTRASONIC MODULE) is activated, and the volume average particle diameter of the seed particles ( Calculate the arithmetic mean diameter in the volume-based particle size distribution. The measurement conditions are shown below.

Medium = Water Refractive index of medium = 1.333
Refractive index of solid = refractive index of seed particles PIDS relative concentration: about 40-55%

[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 include di (2-ethylhexyl) sulfosuccinate, polyoxyethylene nonylphenyl ether phosphate, lauryl sulfate, alkenyl succinate, At least one of oxyethylene styrenated phenyl ether sulfate salt and polyoxyethylene styrenated phenyl ether phosphate is used, and the surfactant content in the polymer particles of Examples and Comparative Examples is as follows: It measured by the method shown in.

Approximately 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 performing ultrasonic extraction at room temperature for 15 minutes, centrifugation is performed at 3500 rpm for 15 minutes, and the resulting supernatant is used as a test solution.

Measure the surfactant concentration in the test solution 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.

-Preparation of calibration curve for 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.

-How to create a calibration curve for polyoxyethylene nonylphenyl ether phosphate-
After preparing about 1000 ppm intermediate standard solution (methanol solution) of polyoxyethylene nonylphenyl ether phosphate, it is further diluted stepwise with methanol to 0.1 ppm, 0.5 ppm, 1.0 ppm, 2.0 ppm, 10. A standard solution for preparing a 0 pm 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 = 502.3 (precursor ion) → 485.2 (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.

-How to create a calibration curve for lauryl sulfate-
Prepare a standard curve of 0.1 ppm, 0.2 ppm, 0.5 ppm, 1.0 ppm, and 2.0 ppm by preparing an intermediate standard solution (methanol solution) of about 1000 ppm of lauryl sulfate and then diluting it stepwise with methanol. 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 = 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.

-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.

-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.

-Preparation of calibration curve for polyoxyethylene styrenated phenyl ether phosphate-
After preparing about 1000 ppm intermediate standard solution (methanol solution) of polyoxyethylene styrenated phenyl ether phosphate, 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.

-LC measurement conditions-
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

-MS measurement conditions-
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
Monitor ion (m / Z):
Di (2-ethylhexyl) sulfosuccinate (n = 421.3 / n2 = 227.2)
Polyoxyethylene nonylphenyl ether phosphate (n = 502.3 / n2 = 485.2)
Lauryl sulfate (n = 421.3 / n2 = 227.2)
Alkenyl succinate (n = 339.3 / n2 = 295.2)
Polyoxyethylene styrenated phenyl ether sulfate ester salt (n = 601.4 / n2 = 301.2)
Polyoxyethylene styrenated phenyl ether phosphate (n = 601.4 / n2 = 301.2)

[Method for measuring specific surface area of polymer particles]
The specific surface area of the polymer particles was measured by the BET method (nitrogen adsorption method) described in ISO 9277 1st edition JIS Z 8830: 2001. For the target polymer particles, the BET nitrogen adsorption isotherm was measured using an automatic specific surface area / pore distribution measuring device Tristar 3000 manufactured by Shimadzu Corporation, and the specific surface area was determined from the nitrogen adsorption amount using the BET multipoint method. Was calculated. After performing the pretreatment by the heated gas purge, the measurement was performed using the constant volume method under the condition of the adsorbate cross section of 0.162 nm ² using nitrogen as the adsorbate. Specifically, the pretreatment is performed by heating the container containing the polymer particles at 65 ° C., performing a nitrogen purge for 20 minutes, allowing to cool to room temperature, and then heating the container at 65 ° C. This was performed by performing vacuum deaeration until the pressure in the container was 0.05 mmHg or less.

[Calculation method of surfactant content per unit surface area of polymer particles]
From the content of the surfactant in the polymer particles measured by the measurement method described above and the specific surface area of the polymer particles measured by the measurement method described above, per unit surface area of the polymer particles by the following calculation formula: The surfactant content in was calculated.

(Content of surfactant per unit surface area of polymer particles) (g / m ² ) = (Content of surfactant in polymer particles) (g / per 1 g of polymer particles)
÷ Specific surface area of polymer particles (m ² / g per polymer particle)

[Method for measuring content of by-product (emulsion polymerization product) in polymer particles (solvent dispersion method)]
When the polymer particles are dispersed in water and centrifuged, the polymer particles having the target particle size settle, while the by-product (emulsion polymerization product) contained in the polymer particles floats in a small amount. Make up the supernatant with the water. Therefore, here, the content of the seed polymerization by-product (emulsion polymerization product) in the polymer particles is measured as the content of the non-volatile component in the supernatant.

[Preparation of supernatant]
First, 5.0 g of polymer particles obtained in each example and each comparative example are placed in a sample bottle having an internal volume of 50 ml, and 15.0 g of water is added. Thereafter, the polymer particles are dispersed in water by performing a dispersion treatment for 60 minutes using an ultrasonic cleaner ("ULTRASONIC CLEANER VS-150" manufactured by VervoCrea Inc., oscillation frequency: 50 Hz, high frequency output: 150 W). To obtain a dispersion. When the polymer particles are difficult to disperse in water, the polymer particles may be dispersed in water after being wetted with a trace amount (upper limit 0.8 g) of alcohol (for example, ethanol).

Next, 20.0 g of the above dispersion is put into a centrifuge tube having an inner diameter of 24 mm, for example, a centrifuge tube having an internal volume of 50 mL and an inner diameter of 24 mm (manufactured by Thermo Fisher Scientific, trade name “Nalgen (registered trademark) 3119-0050”). The centrifuge tube is set in a rotor, for example, an angle rotor (model number “RR24A”, manufactured by Hitachi Koki Co., Ltd., in which eight centrifuge tubes with an internal volume of 50 mL are set), and a centrifuge, for example, a high-speed cooling centrifuge (high -Speed refrigerated centrifuge (model number "CR22GII", manufactured by Hitachi Koki Co., Ltd.) is set with the rotor described above, and using the high-speed cooling centrifuge, K-factor 6943 (when the angle rotor is used, the rotation speed is 4800 rpm) (K factor sometimes becomes 6943) After centrifugation at a rotational time 30 minutes, collecting the supernatant.

[Quantitative evaluation of by-products (emulsion polymerization products)]
Next, the content of by-products (emulsion polymerization product) contained in 5.0 g of the collected supernatant liquid is evaluated. That is, first, 5.0 g of the supernatant liquid is weighed into a sample bottle having a weight of 10 ml in advance and weighed in a vacuum oven at a temperature of 60 ° C. for 5 hours to evaporate water. The weight (g) of the sample bottle containing the evaporated dry residue, ie non-volatile components, is weighed.

And from the weight (g) of the sample bottle containing the non-volatile component, the weight (g) of the sample bottle, and the weight (g) (= 5.0 g) of the supernatant liquid in the sample bottle, the following calculation formula To calculate the concentration (% by weight) of a non-volatile component (corresponding to a by-product (emulsion polymerization product)) in the supernatant.

(Concentration of non-volatile components in the supernatant) (wt%)
= {(Weight of sample bottle containing non-volatile components) (g)
-(Weight of sample bottle) (g)}
÷ (Weight of supernatant in sample bottle) (g) x 100

[Method for measuring gel fraction of polymer particles]
The gel fraction of the polymer particles indicates the degree of crosslinking of the polymer particles, and is measured by the following method. That is, first, 1.0 g of polymer particles as a sample and 0.03 g of boiling stone are precisely weighed and put into a 200 mL eggplant flask, and further 100 mL of toluene is added, and then a cooling tube is connected to the eggplant flask. The eggplant flask is immersed in an oil bath that is attached and maintained at 130 ° 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. Filtration is performed using a Buchner funnel type filter 3G (glass particle pore diameter 20-30 μm, volume 30 mL), and the solid content is recovered in the Buchner funnel type 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 type filter 3G, the glass fiber filter, and the total weight of the solid matter are measured in a state where the Buchner funnel type filter 3G contains the solid matter. Then, the weight (g) of the dry powder is obtained by subtracting the weight of the Buchner funnel type filter 3G and the glass fiber filter and the weight of the boiling stone from the measured total weight.

Then, using the weight (g) of the dry powder and the weight (g) of the sample put in the eggplant flask, the gel fraction is calculated by the following calculation formula.
Gel fraction (% by weight) = {Dry powder (g) / Sample weight (g)} × 100

[Measurement method of refractive index of polymer particles]
The refractive index of the polymer particles was measured by the Becke method. First, polymer particles are placed on a slide glass, and a plurality of refraction liquids (cargill standard: Cargill standard refraction liquid with a refractive index nD25 of 1.538 to 1.562 are prepared in increments of 0.002 in refractive index difference. ) Is dripped. After mixing the polymer particles and the refractive liquid well, the outline of the polymer particles is observed from above with an optical microscope while irradiating light from a high pressure sodium lamp “NX35” (center wavelength 589 nm) manufactured by Iwasaki Electric Co., Ltd. Observed. And when the outline was not visible, it was judged that the refractive index of a refractive liquid and a polymer particle was equal.

Note that observation with an optical microscope is not particularly problematic as long as it is an observation at a magnification at which the outline of the polymer particles can be confirmed, but an observation magnification of about 500 times is appropriate for polymer particles having a particle diameter of 5 μm. By the above operation, the closer the refractive index of the polymer particle to the refractive liquid, the more difficult it is to see the outline of the polymer particle. Therefore, the refractive index of the refractive liquid that makes the outline of the polymer particle difficult to understand is referred to as the refractive index of the polymer particle. Judged to be equal.

In addition, when there is no difference in the appearance of the polymer particles between the two types of refractive liquid having a refractive index difference of 0.002, the intermediate value between the two types of refractive liquid is set as the refractive index of the polymer particles. It was judged. For example, when a test is performed with refractive liquids having a refractive index of 1.554 and a refractive index of 1.556, if there is no difference in the appearance of polymer particles between the two refractive liquids, an intermediate value of 1.555 between these refractive liquids is overlapped. The refractive index of the coalesced particles was determined.

In the above measurement, the measurement was performed in an environment with a test room temperature of 23 ° C. to 27 ° C.

[Method of evaluating dispersibility of polymer particles in high SP value organic solvent (solvent dispersion method)]
In a special plastic container, 0.05 g of polymer particles and 5.0 g of isopropyl alcohol as a high SP value organic solvent are weighed, and stirred and defoamed (product name “Awatori Netaro AR-100”, stock For 5 minutes to obtain a polymer particle dispersion.

Thereafter, one drop of the polymer particle dispersion was placed on the slide glass, covered with a cover glass, and observed with a digital microscope (model number “VHX-500”, manufactured by Keyence Corporation) at a magnification of 1000 × and a visual field of 300 μm × 300 μm. . And the dispersibility in the high SP value organic solvent was evaluated by the following evaluation criteria.

<Evaluation criteria>
A: Polymer particles are not agglomerated but are very uniformly dispersed (more than 5 polymer particles are agglomerated and less than 3 agglomerates; very dispersible in high SP value organic solvent) good)
○: Polymer particles are uniformly dispersed without agglomeration (more than 5 polymer particles are aggregated and aggregated at 3 to 5 sites; dispersibility in a high SP value organic solvent) good)
Δ: Part of polymer particles is aggregated (5 or more polymer particles are aggregated and aggregated in an amount of 6 to 15; dispersibility in a high SP value organic solvent is slightly poor. )
X: Polymer particles are aggregated (5 or more polymer particles are aggregated and aggregated in 16 or more locations; dispersibility in a high SP value organic solvent is poor)

[Measurement Method of Solubility of One Other Surfactant in Cleaning Liquid with Liquid Temperature of 25 ° C.]
Since the solubility of the liquid solute in the solvent is generally determined by the “cloudiness” or “white turbidity” of the solution obtained by dissolving the liquid solute in the solvent, here, the solubility of the liquid solute with respect to the cleaning liquid having a liquid temperature of 25 ° C. The solubility (D) of one other surfactant was measured by measuring the “permeability” of a solution having a liquid temperature of 25 ° C. obtained by dissolving one other surfactant in a cleaning solution. . In addition, when a part of liquid solute precipitates without melt | dissolving in a solvent, the cloudiness to a transparent liquid (solution) generate | occur | produces and the transmittance | permeability of a solution falls.

The procedure for measuring the solubility (D) of one other surfactant in pure water as a cleaning liquid at a liquid temperature of 25 ° C. is described below.
1) First, 4 ml of pure water is put into a dedicated cell, and the transmittance T _water of pure water at a wavelength of 380 nm is measured.
2) Next, an adjustment liquid is prepared by dissolving one kind of other surfactant Xg in 100 g of pure water in a room temperature atmosphere (25 ° C.). measuring the transmittance _{T S} of the adjusting liquid in the 380 nm.
3) Next, the relative transmittance T of the adjustment liquid with respect to the transmittance of pure water is calculated by the following equation.
T = (T _s ) ÷ (T _water )

Then, while repeatedly changing X, the relative transmittance T of the adjustment liquid is calculated, and T = (T _s ) ÷ (T _water ) = 0.98
Is determined as the solubility S ₀ (g / 4 ml) of one other surfactant. And this solubility S ₀ (g / 4 ml) is expressed by the following formula D = S ₀ × 100/4.
Thus, the solubility D (g / 100 ml) of one other surfactant is converted. The measurement of the transmittance _{T water} and the transmittance _{T S} is ultraviolet visible light spectrophotometer (UV-VISIBLE SPECTROPHOTOMETER): carried out using (Model UV-2450, manufactured by Shimadzu Corporation).

[Seed Particle Production Example 1]
In a separable flask equipped with a stirrer, a thermometer and a reflux condenser, 1250 g of water as an aqueous medium, 64 g of methyl methacrylate as a (meth) acrylic acid ester monomer, and n-octyl mercaptan as a molecular weight regulator 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 70 ° C. Furthermore, while maintaining the internal temperature of the separable flask at 70 ° C., an aqueous solution in which 0.32 g of potassium persulfate as a polymerization initiator was dissolved in 50 g of water was added to the contents in the separable flask, and then polymerization was performed for 5 hours. Reacted.

Thereafter, 256 g of methyl methacrylate and 2.56 g of n-octyl mercaptan as a molecular weight regulator were newly added, and charged into the polymerization reaction solution. Then, the inside of the separable flask was again purged with nitrogen, and the internal temperature of the separable flask was changed. The temperature was raised to 70 ° C. An aqueous solution in which 1.28 g of potassium persulfate as a polymerization initiator was dissolved in 50 g of water while maintaining the internal temperature of the separable flask at 70 ° C. was added to the contents in the separable flask, and then the polymerization reaction was performed for 12 hours. I let you.

The reaction liquid after polymerization was filtered through a 400 mesh (32 μm mesh) wire mesh to prepare a slurry containing 20% by weight of seed particles (referred to as seed particles (1)) made of polymethyl methacrylate as a solid content. The seed particles (1) contained in this slurry were true spherical particles having a volume average particle diameter of 0.54 μm.

[Seed Particle Production Example 2]
In a separable flask equipped with a stirrer, a thermometer and a reflux condenser, 1450 g of water as an aqueous medium, 250 g of methyl methacrylate as a (meth) acrylic acid ester monomer, and n-octyl mercaptan as a molecular weight regulator 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 70 ° C. Furthermore, while maintaining the internal temperature of the separable flask at 70 ° C., an aqueous solution in which 1.25 g of potassium persulfate as a polymerization initiator was dissolved in 50 g of water was added to the contents in the separable flask and then polymerized for 12 hours. Reacted.

The reaction liquid after polymerization was filtered through a 400 mesh (mesh 32 μm) wire mesh to prepare a slurry containing 14% by weight of seed particles (referred to as seed particles (2)) made of polymethyl methacrylate as a solid content. The seed particles (2) contained in this slurry were true spherical particles having a volume average particle diameter of 0.42 μm.

[Seed Particle Production Example 3]
In a 5 L reactor equipped with a stirrer and a thermometer, 3300 g of water as an aqueous medium, 360 g of methyl methacrylate as a (meth) acrylic acid ester monomer, and n-octyl mercaptan as a molecular weight regulator 6 g was added, and the slurry of seed particles (2) produced in Seed Particle Production Example 2 was added to 35.0 g as solid content (seed particles), and the contents were replaced with nitrogen while stirring the contents. The internal temperature of the reactor was raised to 70 ° C. Furthermore, while maintaining the internal temperature of the reactor at 70 ° C., an aqueous solution in which 1.8 g of potassium persulfate as a polymerization initiator was dissolved in 60 g of water was added to the contents in the reactor, and then the polymerization reaction was performed for 12 hours. It was.

The reaction liquid after polymerization was filtered through a 400 mesh (mesh 32 μm) wire mesh to prepare a slurry containing 10% by weight of seed particles (hereinafter referred to as seed particles (3)) made of polymethyl methacrylate as a solid content. . The seed particles (3) contained in this slurry were true spherical particles having a volume average particle diameter of 1.02 μm.

[Example 1: Production example of polymer particles]
(1) Polymerization step 400 g of methyl methacrylate (MMA) as a (meth) acrylic acid ester monomer, 300 g of styrene (St) as a styrene monomer, and ethylene as a polyfunctional vinyl monomer A monomer mixture obtained by dissolving 6 g of benzoyl peroxide as a polymerization initiator in 300 g of glycol dimethacrylate (EGDMA), anionic property having no polyoxyethylene chain in 1000 g of ion-exchanged water as an aqueous medium Sodium di (2-ethylhexyl) sulfosuccinate (manufactured by NOF Corporation, product name “Lapisol (registered trademark) A-80” as a surfactant (other surfactant), solubility in water at a liquid temperature of 25 ° C .; 1.5 g / 100 ml) is mixed with a pure component of 10 g and mixed with a homomixer ("Primics Co., Ltd." TK homomixer MARKII 2.5 type ") and treated at a rotational speed of 10,000 rpm for 10 minutes to obtain an emulsion. 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 9.6 g, and stirred at 30 ° C. for 5 hours. Got.

To this dispersion, polyoxyethylene nonylphenyl ether sodium phosphate (product name “Phosphanol (registered trademark) LO-529” manufactured by Toho Chemical Co., Ltd.) as an anionic surfactant having a polyoxyethylene chain was added. 2000 g of an aqueous solution in which 10 g as a pure component and 0.60 g of sodium nitrite as a polymerization inhibitor are dissolved is added, and then a polymerization reaction is performed by stirring at 80 ° C. for 5 hours and then at 105 ° C. for 3 hours. A slurry of particles (hereinafter referred to as slurry (1)) was obtained 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-resistant container 2 (specifically, the upper space S of the filter medium 3) was pressurized to 0.15 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 becomes 2.10 kg (70% of the weight of water used in the polymerization step) or more and the internal pressure of the pressure vessel 2 becomes 0.10 MPa (2/3 of the pressure at the time of pressurization) or less. The pressurization was finished. 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 2.24 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 45.0 minutes. Therefore, the amount X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0498 kg / min.

(3) Washing process With the polymer particle cake held on the filter medium 3, water at 60 ° C. as a washing liquid (60 ° C. water was also used in the washing steps in other examples and comparative examples) After being supplied onto the filter medium 3 in the container 2, the compressed gas is supplied to the upper space S of the filter medium 3 in the pressure-resistant container 2 by a compressed gas supply machine so that the inside of the pressure-resistant container 2 (specifically, the filter medium 3 The upper space S) was pressurized to 0.10 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 of the weight of the polymer particles obtained in the polymerization process (total amount of vinyl monomers used in the polymerization process 1000 g). The test was performed until the electric conductivity of water became 2.0 times or less (specifically, 15 μS or less) and the internal pressure of the pressure vessel 2 became 0.066 MPa (2/3 of the pressure during pressurization) or less.

In addition, the lower limit value B _L (kg) and the upper limit value B _H (kg) of the weight of the cleaning liquid calculated by the above calculation formulas (4) and (5) for one type of other surfactant used in the polymerization step. Was as follows.

B _L = (10 (g) ÷ 1.5 (g / 100 ml)) × 1.8 = 12.0 (kg)
B _H = (10 (g) ÷ 1.5 (g / 100 ml)) × 2.3 = 15.3 (kg)
Weight G ₂ of water as a cleaning solution used in the washing step of the present embodiment is 13.0 kg (13.0 times the weight of the resulting polymer particles in the polymerization step), the lower limit value B _L or more, the The weight was within the range of the upper limit _BH or less.

Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 10.4 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 140.5 minutes. Therefore, the amount Y of the medium that passed through the filter medium in the washing step per unit time was 0.0740 kg / min.

(4) Post-processing step [Drying step]
The polymer particles after washing obtained in the washing step were measured by the Karl Fischer method under the following drying conditions using a vacuum drier (crushing drier), and the water content of the polymer particles was 1.0 wt. Dry until less than%.
(Drying conditions)
Degree of vacuum: -0.1 to -0.3 MPa
Temperature: 50-60 ° C

[Classification process (removal of coarse particles)]
The polymer particles after drying obtained in the drying step are subjected to an air classifier (“Turbo Classifier (registered trademark) TC-15” manufactured by Nisshin Engineering Co., Ltd.), The particles were classified so that particles having a particle size of 2.5 times or more were removed, and target polymer particles were obtained.

(Confirmation of modification of surfactant having polyoxyethylene chain to polymer particle surface)
For the polymer particles of Example 1, polyoxyethylene nonylphenyl ether phosphate as an anionic surfactant having a polyoxyethylene chain by the method for measuring the surfactant content described above (ultrasonic extraction time 15 minutes) The sodium content was measured and found to be 0.79% by weight.

From this measurement result alone, the possibility that a surfactant having a polyoxyethylene chain is taken into the polymer particles cannot be denied. Therefore, the polymer particles were extracted by immersing them in methanol, and the change over time in the amount of the surfactant having a polyoxyethylene chain contained in the extraction component was observed. When the extraction time is short (15 to 30 minutes), the extracted component is generally composed of only components extracted from the surface of the polymer particles, and from the inside of the polymer particles contained in the extracted component as the extraction time increases. It is thought that the ratio of the extracted component increases.

For the polymer particles of Example 1, except that the ultrasonic extraction time was changed to 30 minutes, 12 hours, and 24 hours, respectively, in the same manner as the method for measuring the surfactant content described above, polyoxyethylene nonyl was used. When the content of sodium phenyl ether phosphate (amount of surfactant having a polyoxyethylene chain contained in the extraction component) was measured, it was 0.79% by weight, 0.80% by weight, and 0.80% by weight, respectively. Met.

Further, for the polymer particles of Example 1, water was used instead of methanol as the extraction liquid, and the surfactant extraction agent described above was used except that the ultrasonic extraction time was changed to 30 minutes, 12 hours, and 24 hours, respectively. When the content of polyoxyethylene nonylphenyl ether sodium phosphate (amount of surfactant having a polyoxyethylene chain contained in the extraction component) was measured in the same manner as in the content measurement method, each was 0.003. %, 0.004%, and 0.004% by weight. These measurement results are summarized in Table 1.

As can be seen from the results in Table 1, in the case where either methanol or water is used as the extraction liquid, the polyoxy contained in the extracted component can be observed even if the extraction time is 30 minutes → 12 hours → 24 hours. No significant increase in the amount of sodium ethylene nonylphenyl ether phosphate was observed. Therefore, there is no extraction of polyoxyethylene nonylphenyl ether sodium phosphate from the inside of the polymer particle (very little), that is, no surfactant having a polyoxyethylene chain is taken into the polymer particle. It was judged.

(Confirmation of by-product (emulsion polymerization product))
FIG. 2 shows an SEM image of the polymer particles immediately after the polymerization reaction obtained in Example 1, and FIG. 3 shows an SEM image of the polymer particles obtained after the solid-liquid separation step and the washing step in Example 1. . From FIG. 2, it was confirmed that particles having a particle size of about 100 to 200 nm, which is a by-product (emulsion polymerization product), adhere to the surface of the polymer particles. From FIG. 3, it was confirmed that the by-product (emulsion polymerization product) hardly adhered to the surface of the polymer particles (very slightly adhered).

[Example 2: Production example of polymer particles]
As an anionic surfactant having no polyoxyethylene chain (another surfactant), sodium lauryl sulfate (manufactured by Kao Corporation, product name “Di (2-ethylhexyl) sodium sulfosuccinate”) Emal (R) 2FG "liquid solubility temperature 25 ° C. water; 10 g / 100 ml) was 50g used as pure content, the total weight _{G 1} is 2.30kg next filtrate obtained by solid-liquid separation step (medium) The solid liquid is adjusted so that the time T ₁ from the start of passing the medium (water) contained in the crude product P through the filter medium 3 to the end of the passage of the medium through the filter medium 3 is 50.0 minutes. and changing the conditions of the separation process, to change the weight G ₂ of water as a cleaning liquid used in the washing step 10.5 kg (10.5 times the weight of the resulting polymer particles in the polymerization process), the washing liquid Time T ₂ spent from the start of passing the timber 3 until the wash of 8.4 kg (0.8 times the weight of the weight G ₂ of water as a cleaning solution used in the washing step) to pass through the filter medium 3 The target polymer particles were obtained in the same manner as in Example 1 except that the washing process conditions were changed so that (min) was 150.2 minutes.

The amount X per unit time of the medium that passed through the filter medium in the solid-liquid separation process was 0.0460 kg / min, and the amount Y of the medium that passed through the filter medium in the washing process was 0.0559 kg / min. .

Further, the lower limit value B _L (kg) and the upper limit value B _H (kg) of the weight of the cleaning liquid calculated by the above calculation formulas (4) and (5) for one type of other surfactant used in the polymerization step. Was as follows.

B _L = (50 (g) ÷ 10 (g / 100 ml) × 1.8 = 9.0 (kg)
B _H = (50 (g) ÷ 10 (g / 100 ml)) × 2.3 = 11.5 (kg)
Weight G ₂ of water as the cleaning liquid used in the washing step of the present embodiment is 10.5 kg (10.5 times the weight of the resulting polymer particles in the polymerization step), the lower limit value B _L or more, the The weight was within the range of the upper limit _BH or less.

[Example 3: Production Example of Polymer Particles]
As an anionic surfactant having no polyoxyethylene chain (other surfactant), dipotassium alkenyl succinate (manufactured by Kao Corporation, instead of pure di- (2-ethylhexyl) sulfosuccinate sodium as a pure component of 10 g) The target polymer particles were obtained in the same manner as in Example 1 except that 10 g of the product name “Latemul (registered trademark) ASK”, solubility in water at a liquid temperature of 25 ° C .; 1.7 g / 100 ml) was used as a pure component. Got.

The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.30 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 40.9 minutes. Therefore, the quantity X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0562 kg / min.

B _L = (10 (g) ÷ 1.7 (g / 100 ml) × 1.8 = 10.6 (kg)
B _H = (10 (g) ÷ 1.7 (g / 100 ml)) × 2.3 = 13.5 (kg)
Weight G ₂ of water as a cleaning solution used in the washing step of the present embodiment is 13.0 kg (13.0 times the weight of the resulting polymer particles in the polymerization step), the lower limit value B _L or more, the The weight was within the range of the upper limit _BH or less.

Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 10.4 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 132.0 minutes. Therefore, the amount Y of the medium that passed through the filter medium in the washing step per unit time was 0.0788 kg / min.

[Example 4: Production Example of Polymer Particles]
As an anionic surfactant having a polyoxyethylene chain, polyoxyethylene nonylphenyl ether sodium phosphate is replaced with 10 g of pure polyoxyethylene styrenated phenyl ether ammonium sulfate (Daiichi Kogyo Seiyaku Co., Ltd., product 10 g of pure “Haitenol (registered trademark) NF-08”) was used, and 10.4 kg (the weight G of water as the cleaning liquid used in the cleaning step) after starting to pass the cleaning liquid through the filter medium 3 Except that the conditions of the cleaning process were changed so that the time T ₂ (min) taken until the cleaning liquid of 0.8 times the weight of ₂ ) passed through the filter medium 3 was 129.0 minutes. Similarly, target polymer particles were obtained.

Note that the total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.28 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 41.0 minutes. Therefore, the amount X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0556 kg / min. Moreover, the amount Y per unit time of the medium that passed through the filter medium in the washing step was 0.0806 kg / min.

Further, the lower limit value B _L (kg) and the upper limit value B _H (kg) of the weight of the cleaning liquid calculated by the above calculation formulas (4) and (5) for one type of other surfactant used in the polymerization step. These are the same as in Example 1. The weight G ₂ of water as the cleaning liquid used in the cleaning step of this example is 13.0 kg (13.0 times the weight of the polymer particles obtained in the polymerization step), and the lower limit value B _L (= 12). 0.0 (kg)) or more and the weight within the range of the upper limit B _H (= 15.3 (kg)) or less.

[Example 5: Production example of polymer particles]
As an anionic surfactant having a polyoxyethylene chain, polyoxyethylene nonylphenyl ether sodium phosphate is replaced with 10 g of pure polyoxyethylene styrenated phenyl ether phosphate (Daiichi Kogyo Seiyaku Co., Ltd., product 10 g of pure “Plysurf (registered trademark) AL”) was used as a pure component, and the total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step was 2.25 kg, and the medium contained in the crude product P ( The condition of the solid-liquid separation step is changed so that the time T ₁ from the start of passing the water) through the filter medium 3 to the end of the passage of the medium through the filter medium 3 is 40.8 minutes. passing cleaning liquid started from 10.4 kg (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) is the filter medium 3 that is passed through a filter medium 3 Time T _{2 (min)} spent until the are except for changing the conditions of the washing process so as to 133.5 minutes, in the same manner as in Example 1 to obtain a polymer particle of interest.

The amount X of the medium per unit time that passed through the filter medium in the solid-liquid separation step was 0.0551 kg / min. The amount Y of the medium that passed through the filter medium in the washing step per unit time was 0.0779 kg / min.

[Example 6: Production example of polymer particles]
As the surfactant used to obtain an emulsion in the polymerization step, sodium di (2-ethylhexyl) sulfosuccinate is used as a pure component in place of a pure component of 10 g, and a polyoxyethylene chain-containing anionic surfactant. 20 g of pure oxyethylene nonylphenyl ether phosphate (manufactured by Toho Chemical Co., Ltd., product name “Phosphanol (registered trademark) LO-529”) was used as a pure component, and polyoxyethylene was used for the dispersion in the polymerization process. Sodium nonylphenyl ether phosphate was not added (instead of 2000 g of an aqueous solution in which 10 g of polyoxyethylene nonylphenyl ether sodium phosphate as a pure component and 0.60 g of sodium nitrite were dissolved as an aqueous solution to be added to the dispersion) Dissolved sodium nitrite 0.60g Was used an aqueous solution 2000 g) it, and the weight _{G 2} of water as the cleaning liquid used in the cleaning process of this embodiment 10.0 kg (10.0 times the weight of the resulting polymer particles in the polymerization process) After the start of passing the cleaning liquid through the filter medium 3, 8.0 kg (0.8 times the weight of water G ₂ as the cleaning liquid used in the cleaning process) of the cleaning liquid passes through the filter medium 3. The target polymer particles were obtained in the same manner as in Example 1 except that the conditions of the washing process were changed so that the time T ₂ (min) spent until the time became 100.6 minutes.

The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation process of this example is 2.29 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 43.0 minutes. Therefore, the quantity X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0533 kg / min. Further, the amount Y of the medium that passed through the filter medium in the washing step per unit time was 0.0795 kg / min.

[Example 7: Production example of polymer particles]
Styrene (St) is not used, the amount of methyl methacrylate (MMA) used is changed to 700 g, and 10.4 kg (water as the cleaning liquid used in the cleaning process) is started after passing the cleaning liquid through the filter medium 3. Except that the cleaning process conditions were changed so that the time T ₂ (min) required for the cleaning liquid of 0.8 times the weight G ₂ ) to pass through the filter medium 3 was 143.8 minutes. In the same manner as in Example 1, target polymer particles were obtained.

The total weight G ₁ of the solid-liquid filtrate obtained in the separation step of the present example (medium) is 2.31 kg, 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 43.2 minutes. Therefore, the amount X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0535 kg / min. In addition, the amount Y per unit time of the medium that passed through the filter medium in the washing step was 0.0723 kg / min.

[Example 8: Production example of polymer particles]
Without using methyl methacrylate (MMA), change the amount of styrene (St) to 900 g, change the amount of ethylene glycol dimethacrylate (EGDMA) to 100 g, and start passing the cleaning liquid through the filter medium 3 Then, the time T ₂ (min) spent until 10.4 kg (0.8 times the weight G ₂ of the weight of water used as the cleaning liquid used in the cleaning process) of the cleaning liquid passes through the filter medium 3 is 137.5 minutes. The target polymer particles were obtained in the same manner as in Example 1 except that the conditions of the washing step were changed so that

The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.30 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 44.0 minutes. Therefore, the amount X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0523 kg / min. In addition, the amount Y of the medium that passed through the filter medium in the washing step per unit time was 0.0756 kg / min.

[Example 9: Production example of polymer particles]
Instead of adding the slurry of seed particles (1) to a solid content (seed particles) of 9.6 g, the slurry of seed particles (3) obtained in Production Example 3 of seed particles is replaced with the solid content (seed 10.4 kg from the start of passing the cleaning liquid through the filter medium 3 (0.8 times the weight of water G ₂ as the cleaning liquid used in the cleaning step) The target polymer particles were obtained in the same manner as in Example 1 except that the washing process conditions were changed so that the time T ₂ (min) required for the washing liquid to pass through the filter medium 3 was 130.0 minutes. Got.

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 45.0 minutes. Therefore, the quantity X per unit time of the medium that passed through the filter medium in the solid-liquid separation process was 0.0544 kg / min. Further, the amount Y of the medium that passed through the filter medium in the washing step per unit time was 0.0800 kg / min.

[Comparative Example 1: Production Example of Polymer Particles]
The total weight G ₁ is 2.33kg next filtrate obtained by solid-liquid separation step (medium), the filter medium 3 of the medium a medium contained in the crude product P (water) from the start of passing the filter medium 3 The conditions of the solid-liquid separation process were changed so that the time T ₁ until the passage of the water was finished was 47.5 minutes, and the washing process was omitted (the weight G ₂ of the water as the washing liquid used in the washing process was set to 0). In the same manner as in Example 1, the intended polymer particles were obtained. The amount X of the medium per unit time that passed through the filter medium in the solid-liquid separation step was 0.0491 kg / min.

[Comparative Example 2: Production Example of Polymer Particles]
The total weight G ₁ is 2.41kg next filtrate obtained by solid-liquid separation step (medium), the filter medium 3 of the medium a medium contained in the crude product P (water) from the start of passing the filter medium 3 The condition of the solid-liquid separation process was changed so that the time T ₁ until the passage of water was 45.0 minutes, and the weight G ₂ of water as a cleaning liquid used in the cleaning process was 5.0 kg (obtained in the polymerization process). The weight of water as the cleaning liquid used in the cleaning step is 0. After the start of passing the cleaning liquid through the filter medium 3, the weight of water G ₂ as the cleaning liquid used in the cleaning step is 0. .Times.8 times the weight) of the washing liquid passed through the filter medium 3, except that the washing process conditions were changed so that the time T ₂ (min) was 48.6 minutes. The target polymer particles were obtained.

The amount X of medium passing through the filter medium in the solid-liquid separation process was 0.0536 kg / min, and the amount Y of medium passing through the filter medium in the washing process was 0.0823 kg / min. .

[Comparative Example 3: Production Example of Polymer Particles]
The total weight G ₁ is 2.39kg next filtrate obtained by solid-liquid separation step (medium), the filter medium 3 of the medium a medium contained in the crude product P (water) from the start of passing the filter medium 3 The solid-liquid separation process conditions were changed so that the time T ₁ until the end of the passage of water was 47.7 minutes, and the weight G ₂ of water as the cleaning liquid used in the cleaning process was 5.0 kg (obtained in the polymerization process). The weight of water as the cleaning liquid used in the cleaning step is 0. After the start of passing the cleaning liquid through the filter medium 3, the weight of water G ₂ as the cleaning liquid used in the cleaning step is 0. .Times.8 times the weight) of the washing liquid passing through the filter medium 3 except that the washing process conditions were changed so that the time T ₂ (min) was 55.2 minutes. The target polymer particles were obtained.

The amount X of medium passing through the filter medium in the solid-liquid separation step was 0.0501 kg / min, and the amount Y of medium passing through the filter medium in the washing process was 0.0725 kg / min. .

[Comparative Example 4: Production Example of Polymer Particles]
Polyoxyethylene nonylphenyl ether sodium phosphate is replaced with 10g pure polyvinyl alcohol (PVA) (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name "GOHSENOL GM-14L") as a polymer dispersion stabilizer. As the total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step is 2.35 kg, and the medium (water) contained in the crude product P is started to pass through the filter medium 3. After changing the conditions of the solid-liquid separation step so that the time T ₁ until the passage of the medium through the filter medium 3 is 44.8 minutes and starting to pass the cleaning liquid through the filter medium 3, 10. 4kg wash (0.8 times the weight of the weight _{G 2} of water as a cleaning solution used in the washing step) spends to pass through the filter medium 3 time _T 2 (min) is 142.9 minutes The conditions of the washing process was changed to, in the same manner as in Example 1 to obtain a polymer particle of interest.

The amount X of medium passing through the filter medium in the solid-liquid separation step was 0.0525 kg / min, and the amount Y of medium passing through the filter medium in the washing step was 0.0728 kg / min. .

[Example 10: Production example of polymer particles]
Polyoxyethylene styrenated phenyl as a nonionic surfactant having a polyoxyethylene chain instead of 10 g of pure polyoxyethylene nonylphenyl ether sodium phosphate as an anionic surfactant having a polyoxyethylene chain ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., product name "NOIGEN (R) EA-167") and 10g used as pure content, the total weight _{G 1} of the filtrate obtained by solid-liquid separation step (medium) 2. 29 kg, and the time T ₁ from the start of passing the medium (water) contained in the crude product P through the filter medium 3 to the end of the passage of the medium through the filter medium 3 is 51.0 minutes. Except having changed the conditions of a solid-liquid separation process, it carried out similarly to Example 1, and obtained the target polymer particle.

The amount X of the medium per unit time that passed through the filter medium in the solid-liquid separation step was 0.0499 kg / min.

Further, the lower limit value B _L (kg) and the upper limit value B _H (kg) of the weight of the cleaning liquid calculated by the above calculation formulas (4) and (5) for one type of other surfactant used in the polymerization step. These are the same as in Example 1. Weight G ₂ of water as a cleaning solution used in the washing step of the present example was 13.0 kg (13.0 times the weight of the resulting polymer particles in the polymerization process).

Further, in the cleaning step of this embodiment, from the start of passing a cleaning liquid to the filter medium 3, 10.4 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 170.0 minutes. Therefore, the amount Y of the medium that passed through the filter medium in the washing step per unit time was 0.0612 kg / min.

[Example 11: Production example of polymer particles]
Addition of pure polyoxyethylene nonylphenyl ether sodium phosphate (product name “Phosphanol (registered trademark) LO-529” manufactured by Toho Chemical Co., Ltd.) as an anionic surfactant having a polyoxyethylene chain The amount is changed from 10 g to 25 g, the total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step becomes 2.35 kg, and the medium (water) contained in the crude product P is allowed to pass through the filter medium 3. The condition of the solid-liquid separation step is changed so that the time T ₁ from the start to the end of the passage of the medium through the filter medium 3 is 43.3 minutes, and the cleaning liquid is started to pass through the filter medium 3. from 10.4kg wash (0.8 times the weight of the weight _{G 2} of water as the cleaning liquid used in the washing step) spends to pass through the filter medium 3 time _T 2 (min) is Do min 126.8 Except conditions of the washing process was changed as, in the same manner as in Example 1 to obtain a polymer particle of interest.

The amount X of medium passing through the filter medium in the solid-liquid separation step was 0.0543 kg / min, and the amount Y of medium passing through the filter medium in the washing step was 0.0820 kg / min. .

[Example 12: Production example of polymer particles]
Addition of pure polyoxyethylene nonylphenyl ether sodium phosphate (product name “Phosphanol (registered trademark) LO-529” manufactured by Toho Chemical Co., Ltd.) as an anionic surfactant having a polyoxyethylene chain After changing the amount from 10 g to 5 g and starting to pass the cleaning liquid through the filter medium 3, 10.4 kg (0.8 times the weight of water G ₂ as the cleaning liquid used in the cleaning process) The target polymer particles were obtained in the same manner as in Example 1 except that the conditions of the washing step were changed so that the time T ₂ (min) spent before passing through the filter medium 3 was 135.5 minutes. .

The total weight G ₁ of the solid-liquid filtrate obtained in the separation step of the present example (medium) is 2.32 kg, 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 45.5 minutes. Therefore, the amount X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0510 kg / min. In addition, the amount Y of the medium that passed through the filter medium in the washing step per unit time was 0.0768 kg / min.

[Example 13: Production example of polymer particles]
Change the weight G ₂ of water as a cleaning liquid used in the washing step 12.1 kg (12.1 times the weight of the resulting polymer particles in the polymerization step), the start of passing a cleaning liquid to the filter medium 3 From the above, the time T ₂ (min) spent until 9.68 kg (0.8 times the weight G ₂ of the weight of water as the cleaning liquid used in the cleaning process) passes through the filter medium 3 is 110.0 minutes. The target polymer particles were obtained in the same manner as in Example 1 except that the conditions of the washing process were changed. In the washing step of the present embodiment, the amount Y of the medium that has passed through the filter medium per unit time is 0.0880 kg / min.

The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.37 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 43.2 minutes. Therefore, the quantity X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0549 kg / min.

Further, the lower limit value B _L (kg) and the upper limit value B _H (kg) of the weight of the cleaning liquid calculated by the above calculation formulas (4) and (5) for one type of other surfactant used in the polymerization step. These are the same as in Example 1. The weight G ₂ (= 12.1 kg) of water as the cleaning liquid used in the cleaning process of the present example is not less than the lower limit value B _L (= 12.0 (kg)) and the upper limit value B _H (= 15. 3 (kg)) The weight is within the following range.

[Example 14: Production example of polymer particles]
I spent cleaning liquid from the start of passing the filter medium 3, until the washing of 10.4 kg (0.8 times the weight of the weight G ₂ of water as the cleaning liquid used in the washing step) to pass through the filter medium 3 The target polymer particles were obtained in the same manner as in Example 1 except that the conditions of the washing step were changed so that the time T ₂ (min) was 357.4 minutes. In the cleaning process of the present embodiment, the amount Y of the medium that has passed through the filter medium in the cleaning process per unit time is 0.0291 kg / min.

The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.34 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 50.2 minutes. Therefore, the quantity X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0466 kg / min.

[Example 15: Production example of polymer particles]
Change the weight G ₂ of water as a cleaning liquid used in the washing step 12.0 kg (12.0 times the weight of the resulting polymer particles in the polymerization step), the start of passing a cleaning liquid to the filter medium 3 The time T ₂ (min) required for 9.60 kg (0.8 times the weight G ₂ of the water used as the cleaning liquid used in the cleaning process) to pass through the filter medium 3 is 109.0 minutes. The target polymer particles were obtained in the same manner as in Example 1 except that the conditions of the washing process were changed. The amount Y of the medium that has passed through the filter medium in the washing step per unit time is 0.0881 kg / min.

The total weight G ₁ of the filtrate (medium) obtained in the solid-liquid separation step of this example is 2.30 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 41.5 minutes. Accordingly, the amount X of the medium per unit time that passed through the filter medium in the solid-liquid separation step was 0.0554 kg / min.

Further, the lower limit value B _L (kg) and the upper limit value B _H (kg) of the weight of the cleaning liquid calculated by the above calculation formulas (4) and (5) for one type of other surfactant used in the polymerization step. These are the same as in Example 1. The weight G ₂ (= 12.0 kg) of water as the cleaning liquid used in the cleaning process of this example is not less than the lower limit value B _L (= 12.0 (kg)) and the upper limit value B _H (= 15. 3 (kg)) The weight is within the following range.

[Comparative Example 5: Production Example of Polymer Particles]
Addition of pure polyoxyethylene nonylphenyl ether sodium phosphate (product name “Phosphanol (registered trademark) LO-529” manufactured by Toho Chemical Co., Ltd.) as an anionic surfactant having a polyoxyethylene chain The amount was changed from 10 g to 40 g, the weight G ₂ of water as a washing liquid used in the washing step was changed to 5.0 kg (5.0 times the weight of the polymer particles obtained in the polymerization step), and solid-liquid separation the total weight G ₁ is 2.30kg next filtrate obtained in step (medium), passing the medium contained in the crude product P (water) from the start of passing the filter medium 3 of filter medium 3 of the medium time T ₁ of the until terminated changes the conditions of the solid-liquid separation process such that the 42.8 min, and wash solution from the start of passing the filter medium 3 and the cleaning solution used in 4.0 kg (cleaning step Except that the cleaning liquid of 0.8 times the weight of the weight G ₂ water) of time T ₂ spent before passing through the filter medium 3 _(min) has changed the conditions of the washing process so that 49.7 minutes The target polymer particles were obtained in the same manner as in Example 1.

The amount X of medium passing through the filter medium in the solid-liquid separation step was 0.0537 kg / min, and the amount Y of medium passing through the filter medium in the washing step was 0.0805 kg / min. .

[Comparative Example 6: Production Example of Polymer Particles]
Change the weight G ₂ of water as a cleaning liquid used in the washing step 25.0 kg (25.0 times the weight of the resulting polymer particles in the polymerization process), obtained in the solid-liquid separation step filtrate (medium) The total weight G ₁ becomes 2.31 kg, and the time T _{1 from} when the medium (water) contained in the crude product P starts to pass through the filter medium 3 to when the medium passes through the filter medium 3 is 54. 20.0 kg after changing the conditions of the solid-liquid separation process so as to be 2 minutes and starting to pass the cleaning liquid through the filter medium 3 (0. ₂ of the weight G2 of the water as the cleaning liquid used in the cleaning process). Except for changing the conditions of the cleaning process so that the time T ₂ (min) that the cleaning liquid of 8 times the weight) passes through the filter medium 3 is 250.0 minutes, The intended polymer particles were obtained.

The amount X per unit time of the medium that passed through the filter medium in the solid-liquid separation process was 0.0426 kg / min, and the amount Y of the medium that passed through the filter medium in the washing process was 0.0800 kg / min. .

[Comparative Example 7: Production Example of Polymer Particles]
The total weight G ₁ is 2.25kg next filtrate obtained by solid-liquid separation step (medium), the filter medium 3 of the medium a medium contained in the crude product P (water) from the start of passing the filter medium 3 After changing the conditions of the solid-liquid separation step so that the time T ₁ until the passage of the water ends is 21.8 minutes and starting to pass the washing liquid through the filter medium 3, 10.4 kg (in the washing step) The cleaning process conditions were changed so that the time T ₂ (min) required for the cleaning liquid of 0.8 times the weight G ₂ of the water used as the cleaning liquid to pass through the filter medium 3 would be 93.3 minutes. Except that, the target polymer particles were obtained in the same manner as in Example 1.

The amount X of medium passing through the filter medium in the solid-liquid separation step was 0.1032 kg / min, and the amount Y of medium passing through the filter medium in the washing step was 0.1115 kg / min. .

[Comparative Example 8: Production Example of Polymer Particles]
The total weight G ₁ is 2.25kg next filtrate obtained by solid-liquid separation step (medium), the filter medium 3 of the medium a medium contained in the crude product P (water) from the start of passing the filter medium 3 The solid-liquid separation process conditions were changed so that the time T ₁ until the passage of the liquid became 17.7 minutes, and 10.4 kg (for use in the cleaning process) after starting to pass the cleaning liquid through the filter medium 3 The condition of the washing process was changed so that the time T ₂ (min) required for the washing liquid of 0.8 times the weight G ₂ of the water as the washing liquid to pass through the filter medium 3 was 118.3 minutes. Except for this, the same polymer particles as in Example 1 were obtained.

The amount X of medium passing through the filter medium in the solid-liquid separation step is 0.1271 kg / min, and the amount Y of medium passing through the filter medium in the washing step is 0.0879 kg / min. there were.

[Comparative Example 9: Production Example of Polymer Particles]
Time spent washing liquid from the start of passing the filter medium 3 until the washings of 10.4 kg (0.8 times the weight of the weight G ₂ of water as a cleaning solution used in the washing step) to pass through the filter medium 3 The target polymer particles were obtained in the same manner as in Example 1 except that the conditions of the washing step were changed so that T ₂ (min) was 90.0 minutes. The amount Y of the medium per unit time that passed through the filter medium in the washing step was 0.1156 kg / min.

The total weight G ₁ of the solid-liquid filtrate obtained in the separation step of this comparative example (medium) is 2.33 kg, 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 55.2 minutes. Therefore, the quantity X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0422 kg / min.

[Comparative Example 10: Production Example of Polymer Particles]
Change the weight G ₂ of water as a cleaning liquid used in the washing step 3.0 kg (3.0 times the weight of the resulting polymer particles in the polymerization step), the start of passing a cleaning liquid to the filter medium 3 To 2.4 kg (0.8 times the weight G ₂ of the water used as the cleaning liquid used in the cleaning process), the time T ₂ (min) required to pass through the filter medium 3 is 27.3 minutes. Thus, the target polymer particle was obtained like Example 6 except having changed the conditions of the washing | cleaning process.

The total weight G ₁ of the solid-liquid filtrate obtained in the separation step of this comparative example (medium) is 2.25 kg, 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 40.2 minutes. Therefore, the amount X per unit time of the medium that passed through the filter medium in the solid-liquid separation step was 0.0560 kg / min. The amount Y of the medium passed through the filter medium in the washing step per unit time was 0.0880 kg / min.

[Comparative Example 11: Production Example of Polymer Particles]
Polymer particles were prepared according to Example 5 of Patent Document 5 (Japanese Unexamined Patent Application Publication No. 2009-203378). That is, first, 529 g of ion-exchanged water, 1.6 g of 25 mol% ammonia aqueous solution, and 118 g of methanol are put into a four-necked flask equipped with a cooling pipe, a thermometer, and a dropping port, and 3 g of the mixture is added to this mixed solution while stirring. -Add 25 g of methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503) from the dropping port, and hydrolyze and condense 3-methacryloxypropyltrimethoxysilane to prepare organopolysiloxane particles did. Two hours after the start of the reaction, an emulsion of the obtained organopolysiloxane particles was sampled, and the volume average particles were measured by the measurement method described in [Method for measuring volume average particle size of polymer particles and coefficient of variation of particle size]. When the diameter was measured, the volume average particle diameter was 1.9 μm.

Subsequently, polyoxyethylene styrenated phenyl ether sulfate ammonium salt which is an anionic surfactant having a polyoxyethylene chain (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name “Hitenol (registered trademark) NF-08”) In a solution obtained by dissolving 20.0 g (about 19 g as a pure component) with 1750 g of ion-exchanged water, 600 g of styrene (St), 400 g of 1,6-hexanediol dimethacrylate (HDDMA), 2,2′-azobis (2, 4-Dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd., V-65) in a solution of 20 g was added, and TK homomixer (Primics Co., Ltd. (formerly Koki Kagaku Kogyo Co., Ltd.)) was used for 5 at 6000 rpm. Emulsified and dispersed for a minute to prepare an emulsion, and the resulting monomer emulsion was treated with organopolysiloxane. It was added to a solution of emission particles emulsion was further stirred. Two hours after the addition of the monomer emulsion, the reaction solution was sampled and observed with a microscope. As a result, it was confirmed that the organopolysiloxane particles absorbed the monomer and were enlarged.

Next, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere and held at 65 ° C. for 2 hours to perform radical polymerization of the monomer. The reaction solution was cooled and then filtered, and the polymerization product was collected by filtration. At this time, the solid content concentration of the recovered product (the polymerization product collected by filtration) was 67% by weight.

1 kg of ion-exchanged water was added to the recovered product to obtain a solid concentration of 40% by weight, stirred for 30 minutes, and then filtered to recover the washed polymerization product. At this time, the solid content concentration of the recovered product after washing was 60% by weight.

After washing, the recovered material was dried with a dryer at 100 ° C. for 6 hours to obtain organic-inorganic composite particles. With respect to the obtained organic-inorganic composite particles, the volume average particle diameter and the coefficient of variation of the particle diameter were measured by the measurement method described above. The volume average particle diameter was 3.82 μm, and the coefficient of variation of the particle diameter was 7.22%. It was. The obtained organic / inorganic composite particles were measured for the content of the surfactant by the above-described measurement method, and found to be 1940 ppm by weight (0.19% by weight).

The first filtration uses a quantitative filter paper (quantitative filter paper No. 5C, manufactured by Advantech Toyo Co., Ltd.) instead of the filter cloth as the filter medium 3, and the total weight G _{1 of the} filtrate (medium) obtained in the solid-liquid separation step. Is 0.80 kg, and the time T ₁ from the start of passing the medium (water) contained in the crude product P through the filter medium 3 to the end of the passage of the medium through the filter medium 3 is 18.5 minutes. This was performed in the same manner as the solid-liquid separation step of Example 1 except that the conditions of the solid-liquid separation step were changed. Second filtration, 1.0 times the weight of the resulting polymer particles the weight G ₂ of water as a cleaning liquid used in the washing step to a solid concentration of 40 wt% with 1.0 kg (polymerization step ) And starting to pass the cleaning liquid through the filter medium 3, 0.8 kg (0.8 times the weight of water G ₂ as the cleaning liquid used in the cleaning process) of the cleaning liquid passes through the filter medium 3. The condition of the washing process was changed so that the time T ₂ (min) spent before passing was 28.9 minutes, and instead of the filter cloth as the filter medium 3, a quantitative filter paper (quantitative filter paper No. 5C manufactured by Advantech Toyo Co., Ltd.) ) Was used in the same manner as in the cleaning process of Example 1.

The amount X per unit time of the medium that has passed through the filter medium in the solid-liquid separation step is 0.0432 / min, and the amount Y of the medium that has passed through the filter medium in the washing step is 0.0277 kg / min. there were.

[Example 16: Production example of optical film]
To a 10 ml sample tube, 0.20 g of the polymer particles obtained in Example 1 and 1.00 g of isopropyl alcohol as a high SP value organic solvent are added, and an ultrasonic cleaner (“Velvo Crea Co., Ltd.“ ULTRASONIC CLEANER VS-150 ") and stirred for 1 minute to disperse the polymer particles in butyl acetate as an organic solvent to obtain a dispersion. This dispersion further contains 1 acrylic resin (“Acridic® A-817” manufactured by DIC Corporation, 49.0 to 51.0 wt% of toluene and butyl acetate as organic solvents). .50 g was added and stirred for about 2 minutes with the above ultrasonic cleaner to obtain a coating resin composition. After this coating resin composition was allowed to stand for 4 hours, 5.50 g of butyl acetate as an organic solvent was added to the coating resin composition, and the mixture was stirred for 1 minute in the ultrasonic cleaner, and then the coating resin A diluted solution of the composition was obtained.

Using a coater with a 75 μm slit on a 100 μm thick PET film (trade name “FUJIX (registered trademark) OHP film for copying machine” manufactured by Fuji Film Co., Ltd.) having a thickness of 100 μm. Coated. After coating, the film was placed in a drier maintained at 70 ° C. and left for 1 hour to obtain an optical film.

[Example 17: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 2 was used instead of 0.20 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 16 except that 0.20 g of the polymer particles obtained in Example 3 was used instead of 0.20 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 16 except that 0.20 g of the polymer particles obtained in Example 4 was used instead of 0.20 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 16 except that 0.20 g of the polymer particles obtained in Example 5 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 21: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 6 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 22: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 7 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 23: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 8 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 24: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 9 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 12: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 1 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 13: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 2 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 14: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 3 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 15: Comparative Production Example of Optical Film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 4 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 25: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 10 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 26: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 11 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 27: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 12 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 28: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 13 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 29: Production example of optical film]
An optical film was obtained in the same manner as in Example 16, except that 0.20 g of the polymer particles obtained in Example 14 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Example 30: Production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Example 15 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 16: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 5 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 17: Comparative Production Example of Optical Film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 6 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 18: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 7 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 19: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 8 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 20: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 9 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 21: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 10 was used instead of 0.20 g of the polymer particles obtained in Example 1.

[Comparative Example 22: Comparative production example of optical film]
An optical film was obtained in the same manner as in Example 16 except that 0.20 g of the polymer particles obtained in Comparative Example 11 was used instead of 0.20 g of the polymer particles obtained in Example 1.

The optical characteristics of the optical films of Examples 16 to 30 and Comparative Examples 12 to 22 were evaluated by the following method.

[Evaluation method of optical characteristics (small variation in haze)]
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. Measure 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

For Examples 1 to 15 and Comparative Examples 1 to 11, the number of seed particles used in the polymerization process (seed particle number), the composition of the monomers used in the polymerization process (monomer composition), and used in the polymerization process Types of other surfactants and surfactants having polyoxyethylene chains, types of polymer dispersion stabilizers used in the polymerization process, X values in the solid-liquid separation process (amount of medium passed through the filter medium per unit time) (Kg / min)) measurement result, Y value in the washing step (amount of washing liquid that passed through the filter medium per unit time (kg / min)), amount of washing liquid (water) used in the washing step (kg ), Measurement results of volume average particle diameter (μm) and coefficient of variation (CV value (%)) of the obtained polymer particles, measurement results of refractive index of the obtained polymer particles, and obtained Measurement result of gel fraction (%) of polymer particles Table 2 and Table 4.

Further, with respect to the polymer particles obtained in Examples 1 to 15 and Comparative Examples 1 to 11, the measurement results of the specific surface area (m ² / g) of the polymer particles, the inclusion of other surfactants in the polymer particles Measurement result of amount (weight ppm), measurement result of content (weight ppm) of surfactant having polyoxyethylene chain in polymer particle, other interface in polymer particle per unit surface area of polymer particle As a result of measuring the content of the activator (× 10 ⁻³ g / m ² ), the content of the surfactant having a polyoxyethylene chain in the polymer particle per unit surface area of the polymer particle (× 10 ⁻⁵ g / M ² ) measurement results, evaluation results of dispersibility of the polymer particles in the high SP value organic solvent, and measurement results of the content of by-products (emulsion polymerization products) in the polymer particles are shown in Table 3. And in Table 5. Tables 3 and 5 also show the measurement results of the haze difference (%) of the optical films and the evaluation results of the optical properties of the optical films of the optical films of Examples 16 to 30 and Comparative Examples 12 to 22.

In Tables 2 and 4, DSS represents sodium di (2-ethylhexyl) sulfosuccinate, LS represents sodium lauryl sulfate, ASK represents dipotassium alkenyl succinate, and POEPS represents polyoxyethylene nonylphenyl ether phosphorus. It represents sodium acid, ASPSE represents polyoxyethylene styrenated phenyl ether ammonium sulfate, POESE represents polyoxyethylene styrenated phenyl ether phosphate ester, PVA represents polyvinyl alcohol, PSE represents polyoxyethylene styrenated phenyl Represents ether.

The filter medium 3 (filter cloth) and the filtrate (that is, the crude product P) of the pressure filter 1 (see FIG. 1) used in the solid-liquid separation step and the washing step of Examples 1 to 15 and Comparative Examples 1 to 11 The area A of the interface is 0.0104 (m ² ). Therefore, in Examples 1 to 15 and Comparative Examples 1 to 11, the upper limit value of the X value satisfying the conditional expression (1) (the amount per unit time of the medium that has passed through the filter medium (kg / min)) is 0. 0572 kg / min. Further, the lower limit value of the Y value satisfying the above conditional expression (2) (the amount per unit time of the cleaning liquid that has passed through the filter medium (kg / min)) is 0.0260 kg / min, and the upper limit value is 0.0884 kg / min. .

From the results shown in Tables 2-5, among the polymer particles obtained in Examples and Comparative Examples in which a surfactant having a polyoxyethylene chain and another surfactant are used in combination, the cleaning liquid (water ) Is 9 times or more (9 kg or more) of the weight of the polymer particles, specifically 10.0 to 13.0 times, and the polymer particles obtained in Examples 1 to 15 are units of polymer particles. While the content of other surfactants per surface area is less than 10.0 × 10 ⁻⁵ g / m ² , specifically 0.88 to 8.38 × 10 ⁻⁵ g / m ² , The washing step was omitted (corresponding to the case where the amount of washing liquid (water) used for washing is 0), and the amount of washing liquid (water) used for washing was less than 9 times the weight of the polymer particles (9 kg) Less), specifically, the polymer particles obtained in Comparative Examples 2, 3, and 5 which are 5.0 times the polymer The content of other surfactants per unit surface area of the particles was higher than 10.0 × 10 ⁻⁵ g / m ² , specifically 131.76 to 413.62 × 10 ⁻⁵ g / m ² . . Therefore, according to the production method of the present invention in which the amount of the cleaning liquid (water) used for the cleaning is 9 times or more the weight of the polymer particles, the other surfactant used in the polymerization step is applied to the polymer particle surfaces. It was observed that the amount of adhesion per unit surface area can be reduced.

From the results shown in Tables 2 to 5, the amount of the cleaning liquid (water) used for cleaning was 18 times or less (18 kg or less), specifically 10.0 to 13.0 times the weight of the polymer particles. In the polymer particles obtained in 1 to 15, the content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 2.0 × 10 ⁻³ g / m ² to 15.0 × 10 ^{−. 3} g / m ² , specifically 2.15 to 12.32 × 10 ⁻³ g / m ² , whereas the amount of cleaning liquid (water) used for cleaning is 18 times the weight of the polymer particles The polymer particles obtained in Comparative Example 6 that is super (exceeding 18 kg), specifically 25.0 times (25.0 kg), are surfactants having polyoxyethylene chains per unit surface area of the polymer particles. content is less than ^{^{2.0 × 10 -3 g / m 2}} , in particular 1.46 × 0 was small and ^-3 g / ^{m 2.} Therefore, according to the production method of the present invention in which the amount of the cleaning liquid (water) used for cleaning is 9 to 18 times the weight of the polymer particles, the surfactant having polyoxyethylene chains used in the polymerization step It was confirmed that the adhesion amount per unit surface area to the surface of the polymer particles can be within an appropriate range of 2.0 × 10 ⁻³ g / m ² to 15.0 × 10 ⁻³ g / m ² .

Further, the weight obtained in Examples 1 to 15 in which the amount of the washing liquid (water) used for washing is 9 times or more (9 kg or more), specifically 10.0 to 13.0 times the weight of the polymer particles. The coalesced particles had a measured content of by-products (emulsion polymerization products) of less than 1.0% by weight, specifically 0.05 to 0.82% by weight. Omitted (corresponding to the case where the amount of cleaning liquid (water) used for cleaning is 0) Comparative Example 1, and the amount of cleaning liquid (water) used for cleaning is less than 9 times the weight of the polymer particles (less than 9 kg), Specifically, the polymer particles obtained in Comparative Examples 2, 3, 5, 10, and 11 that are 1.0 to 5.0 times have a measured value of the content of by-products (emulsion polymerization products) of 1. More than 0.0% by weight, specifically 1.99 to 4.33% by weight. Therefore, according to the production method of the present invention in which the amount of the cleaning liquid (water) used for the cleaning is 9 times or more the weight of the polymer particles, the content of by-products (emulsion polymerization products) in the polymer particles is reduced. It was found that it can be reduced.

Further, among the polymer particles obtained in Examples / Comparative Examples in which a surfactant having a polyoxyethylene chain and another surfactant are used in combination, the X value (the amount per unit time of the medium passing through the filter medium) ) Is obtained in Examples 1 to 15 having an upper limit value 0.0572 (kg / min) or less (specifically 0.0460 to 0.0566 (kg / min)) satisfying the conditional expression (1). The polymer particles have a content of other surfactants per unit surface area of the polymer particles of 10.0 × 10 ⁻⁵ g / m ² or less, specifically 0.88 to 8.38 × 10 ^−5. While the value is small as g / m ² , the X value is larger than the upper limit value 0.0572 (kg / min) that satisfies the conditional expression (1) (specifically, 0.1032 to 0.1271 (kg / min) The polymer particles obtained in Comparative Examples 7 and 8 are polymers. The content of other surfactants per unit surface area of the particles is as large as 10.0 × 10 ⁻⁵ g / m ² (specifically, 12.33 to 29.79 × 10 ⁻⁵ g / m ² ). It was. Therefore, according to the production method of the present invention in which the X value satisfies the conditional expression (1), it is possible to reduce the amount of other surfactants used in the polymerization step per unit surface area on the polymer particle surface. Admitted.

Examples 1 to 15 in which the X value is not more than the upper limit value 0.0572 (kg / min) satisfying the conditional expression (1) (specifically, 0.0460 to 0.0566 (kg / min)). In the polymer particles obtained in the above, the measured content of the by-product (emulsion polymerization product) was less than 1.0% by weight, specifically 0.05 to 0.82% by weight. , X value is larger than upper limit value 0.0572 (kg / min) satisfying conditional expression (1) (specifically, 0.0762 to 0.1271 (kg / min)) Comparative Examples 7 and 8 The polymer particles obtained in No. 11 had a measured content of by-product (emulsion polymerization product) of 1.0% by weight or more (specifically, 1.98 to 2.33% by weight). . Therefore, according to the production method of the present invention in which the X value satisfies the conditional expression (1), it was confirmed that the content of by-products (emulsion polymerization products) in the polymer particles can be reduced.

In addition, among polymer particles obtained in Examples / Comparative Examples in which a surfactant having a polyoxyethylene chain and another surfactant are used in combination, the Y value (the amount per unit time of the cleaning liquid that has passed through the filter medium) ) Within the range of 0.0260 (kg / min) to 0.0884 (kg / min) satisfying the conditional expression (2) (specifically, 0.0291 to 0.0881 (kg / min)). ) In the polymer particles obtained in Examples 1 to 15, the content of the other surfactant per unit surface area of the polymer particles is 10.0 × 10 ⁻⁵ g / m ² or less, specifically 0.8. While the value is as small as 88 to 8.38 × 10 ⁻⁵ g / m ² , the Y value is larger than the upper limit value 0.0884 kg / min that satisfies the conditional expression (2) (specifically, 0.1115 to 0). 1156 (kg / min)) obtained in Comparative Examples 7 and 9 The obtained polymer particles have a content of other surfactant per unit surface area of the polymer particles of more than 10.0 × 10 ⁻⁵ g / m ² (specifically, 11.95 to 29.79 × 10 ^{− 5} g / m ² ). Therefore, according to the production method of the present invention in which the Y value satisfies the conditional expression (2), it is possible to reduce the adhesion amount per unit surface area of the other surfactant used in the polymerization step to the polymer particle surface. Admitted.

In addition, the polymer particles obtained in Examples 1 to 15 satisfying the conditional expression (2) (specifically, 0.0291 to 0.0881 (kg / min)) are used as by-products. The measured value of the content of (emulsion polymerization product) was less than 1.0% by weight, specifically 0.05 to 0.82% by weight, whereas the Y value was the above conditional expression (2) The polymer particles obtained in Comparative Examples 7 and 9 are larger than 0.0884 kg / min (specifically, 0.1115 to 0.1156 (kg / min)) satisfying the above-mentioned by-product (emulsion polymerization). The measured value of the content of the product was as high as 1.0% by weight or more (specifically, 1.89 to 2.33% by weight). Therefore, according to the production method of the present invention in which the Y value satisfies the conditional expression (2), it was confirmed that the content of by-products (emulsion polymerization products) in the polymer particles can be reduced.

The content of the other surfactant per unit surface area of the polymer particles is 10.0 × 10 ⁻⁵ g / m ² or less (specifically, 0.88 to 8.38 × 10 ⁻⁵ g / m 2). ² ) In the polymer particles of Examples 1 to 15, the content of the other surfactant per unit surface area of the polymer particles is more than 10.0 × 10 ⁻⁵ g / m ² (specifically 11 .95 to 413.62 × 10 ⁻⁵ g / m ² ), it is recognized that the polymer particles of Comparative Examples 1 to 3, 5, and 7 to 9 are excellent in dispersibility in high SP organic solvents. It was.

Also, a coating resin composition comprising the polymer particles of Examples 1 to 15 in which the content of other surfactant per unit surface area of the polymer particles is 10.0 × 10 ⁻⁵ g / m ² or less. In the coated optical films of Examples 16 to 30, the contents of other surfactants per unit surface area of the polymer particles are more than 10.0 × 10 ⁻⁵ g / m ² in Comparative Examples 1 to Compared with the optical films of Comparative Examples 12-14, 16, and 18-20, which are coated with a coating resin composition containing polymer particles of 3, 5, 7-9, there is little haze difference and light diffusibility It was confirmed that there was little unevenness. That is, in an optical film including polymer particles in which the content of another surfactant per unit surface area of the polymer particles is 10.0 × 10 ⁻⁵ g / m ² or less, more uniform optical characteristics (antiglare) And light diffusivity). This indicates that the polymer particles in which the content of other surfactants per unit surface area of the polymer particles is 10.0 × 10 ⁻⁵ g / m ² or less are excellent in dispersion uniformity. Yes.

The content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 2.0 to 15.0 × 10 ⁻³ g / m ² (specifically, 2.15 to 12.32). The polymer particles of Examples 1 to 15 that were × 10 ⁻³ g / m ² ) did not use a surfactant having polyoxyethylene chains (polyoxyethylene chains per unit surface area of the polymer particles). Corresponding to the case where the content of the surfactant having 0 is 0) The content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles of Comparative Example 4 and the polymer particles is 2.0 × 10 ⁻ Compared with the polymer particles of Comparative Examples 6 and 11 which are less than ³ g / m ² (specifically 0.80 to 1.46 × 10 ⁻³ g / m ² ), the dispersibility in organic solvents with high SP value It was recognized that it was excellent.

The polymer particles of Examples 1 to 15 in which the content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 2.0 to 15.0 × 10 ⁻³ g / m ² are used. The optical films of Examples 16 to 30 formed by coating the coating resin composition containing no polyoxyethylene chain surfactant were used (polyoxyethylene chains per unit surface area of the polymer particles). Corresponding to the case where the content of the surfactant is 0) The optical film of Comparative Example 15 obtained by coating the resin composition for coating containing the polymer particles of Comparative Example 4 and the unit surface area of the polymer particles Coating a coating resin composition containing the polymer particles of Comparative Examples 6 and 11 in which the content of the surfactant having a polyoxyethylene chain is less than 2.0 × 10 ⁻³ g / m ² As compared with the optical films of Comparative Examples 17 and 22, the haze difference was small and the light diffusivity was found to be less uneven. That is, in an optical film including polymer particles in which the content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 2.0 to 15.0 × 10 ⁻³ g / m ² , It was observed that uniform optical properties (antiglare and light diffusibility) were obtained. This is because the polymer particles having a polyoxyethylene chain-containing surfactant content per unit surface area of the polymer particles of 2.0 to 15.0 × 10 ⁻³ g / m ² are dispersed uniformly. It shows that it is excellent.

The content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 2.0 to 15.0 × 10 ⁻³ g / m ² (specifically, 2.15 to 12.32). The polymer particles of Examples 1 to 15 that are × 10 ⁻³ g / m ² ) have a content of surfactant having a polyoxyethylene chain per unit surface area of the polymer particles of 15.0 × 10 ^−3. Compared with the polymer particles of Comparative Examples 5 and 10, which are more than g / m ² (specifically, 15.16 to 17.41 × 10 ⁻³ g / m ² ), the dispersibility in organic solvents having a high SP value is improved. It was recognized that it was excellent.

The polymer particles of Examples 1 to 15 in which the content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 2.0 to 15.0 × 10 ⁻³ g / m ² are used. In the optical films of Examples 16 to 30 obtained by coating the coating resin composition, the content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 15.0 × 10 ^−3. Compared with the optical films of Comparative Examples 16 and 21 obtained by coating the coating resin compositions containing the polymer particles of Comparative Examples 5 and 10 that are greater than g / m ² , the haze difference is small and the light diffusibility is uneven. Was found to be small. That is, in an optical film including polymer particles in which the content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 2.0 to 15.0 × 10 ⁻³ g / m ² , It was observed that uniform optical properties (antiglare and light diffusibility) were obtained. This is because the polymer particles having a polyoxyethylene chain-containing surfactant content per unit surface area of the polymer particles of 2.0 to 15.0 × 10 ⁻³ g / m ² are dispersed uniformly. It shows that it is excellent.

Further, the polymer particles of Examples 1 to 15 in which the measured content of the by-product (emulsion polymerization product) is less than 1.0% by weight (specifically 0.05 to 0.82% by weight). Compared with the polymer particles of Comparative Examples 1 to 3, 5, and 7 to 11 in which the measured content of the by-product (emulsion polymerization product) is 1.0% by weight or more, the organic solvent has a high SP value. It was recognized that the dispersibility with respect to was excellent.

Also, an example in which a coating resin composition containing the polymer particles of Examples 1 to 15 in which the measured content of the by-product (emulsion polymerization product) is less than 1.0% by weight is applied. The optical film of 16 to 30 is a coating containing the polymer particles of Comparative Examples 1 to 3, 5, and 7 to 11 in which the measured value of the by-product (emulsion polymerization product) content is 1.0% by weight or more Compared to the optical films of Comparative Examples 12 to 14, 16, and 18 to 22 obtained by coating the resin composition for coating, it was confirmed that the difference in haze was small and the unevenness of light diffusibility was small. That is, in an optical film containing polymer particles whose measured content of by-product (emulsion polymerization product) is less than 1.0% by weight, more uniform optical properties (antiglare and light diffusibility) are obtained. It was observed that it was obtained. This indicates that the polymer particles having a by-product (emulsion polymerization product) content measurement value of less than 1.0% by weight are excellent in dispersion uniformity.

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. 2014-201702 filed in Japan on September 30, 2014. 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 Diameter of the interface (liquid removal surface) of a filter medium and a to-be-filtered material P Crude product S Upper space of filter medium

Claims

Polymer particles containing a surfactant having a polyoxyethylene chain,
The variation coefficient of the particle diameter is 15.0% or less,
The content of the surfactant having a polyoxyethylene chain per unit surface area of the polymer particles is 2.0 to 15.0 × 10 −3 g / m 2 ,
The polymer particles, wherein the content of the other surfactant per unit surface area of the polymer particles is 10.0 × 10 −5 g / m 2 or less.
The polymer particles according to claim 1,
15.0 g of water is added to 5.0 g of the polymer particles, and the polymer particles are dispersed in water by carrying out a dispersion treatment for 60 minutes using an ultrasonic cleaner, and placed in a centrifuge tube having an inner diameter of 24 mm. After centrifuging using K-factor 6943 under the conditions of a rotation time of 30 minutes, when the supernatant liquid is recovered, the concentration of the non-volatile component in the supernatant liquid is less than 1.0% by weight. Polymer particles.
The polymer particles according to claim 1 or 2,
The polymer particle, wherein the surfactant having a polyoxyethylene chain contains at least one of an anionic surfactant having a polyoxyethylene chain and a nonionic surfactant having a polyoxyethylene chain.
The polymer particles according to any one of claims 1 to 3,
A polymer particle, wherein the polymer particle is composed of at least one of a (meth) acrylic polymer, a styrene polymer, and a (meth) acryl-styrene copolymer.
The polymer particles according to any one of claims 1 to 4,
A polymer particle having a gel fraction of 90% or more.
The polymer particles according to any one of claims 1 to 5,
A polymer particle having a refractive index of 1.490 to 1.600.
The polymer particles according to any one of claims 1 to 6,
A polymer particle obtained by absorbing a vinyl monomer in seed particles and polymerizing in the presence of a surfactant containing a surfactant having a polyoxyethylene chain.
The polymer particles according to any one of claims 1 to 7,
Polymer particles for optical members.
The polymer particles according to any one of claims 1 to 8,
Polymer particles for use in an antiglare member.
8. An optical film obtained by coating a coating resin composition comprising the polymer particles according to claim 1 and a binder on a film substrate.
The optical film according to claim 10,
An optical film characterized by being used for antiglare.
A method for producing polymer particles, comprising:
Polymer particles containing a surfactant having a polyoxyethylene chain by polymerizing a vinyl monomer in the presence of a surfactant containing a surfactant having a polyoxyethylene chain in a liquid medium; A polymerization step to obtain a crude product comprising 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 object 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):
2.50 × A ≦ 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)
In the washing step, a washing solution having a weight of 9 to 18 times the weight of the polymer particles held on the filter medium is used.