JP2009138034A - Particles and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide particles which includes an organic polymer and polysiloxane, and the surface of which is not smooth, and to provide a method for manufacturing above particles. <P>SOLUTION: This particle is a complex containing the organic polymer and an organopolysiloxane which does not have a radically polymerizable unsaturated bond, and has a plurality of heights and/or hollows on the surface. The method for manufacturing the particles includes a seed particle production step of producing the organopolysiloxane particles which do not have the radically polymerizable unsaturated bond, an absorption step of permitting a monofunctional monomer having one radically polymerizable double bond and a multifunctional monomer having ≥3 radically polymerizable double bond to be absorbed on the organopolysiloxane particles, and a polymerization step of polymerizing the absorbed monofunctional monomer and multifunctional monomer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to particles that can also be used as constituent particles of an optical member, and a method for producing the particles.

  The shape of the particles obtained by a conventionally known polymerization method such as suspension polymerization, seed polymerization, dispersion polymerization, emulsion polymerization or the like is generally a true sphere. For example, a polysiloxane particle having a (meth) acryloxy group disclosed in Patent Document 1 and containing a vinyl polymer in this structure is a true spherical particle. It is considered that the particles are spherical because the shape is the most stable in terms of energy during the particle generation process. The obtained spherical particles are used for optical member applications such as light scattering particles in an optical film, and in order to sufficiently scatter light, the amount of spherical particles added to the optical member may be increased to some extent. It is normal. However, increasing the amount of particles added causes a decrease in the light transmittance of the optical member itself, which may deteriorate the optical member performance.

As particles other than true spherical particles, porous particles are known as disclosed in Patent Documents 2 to 5, for example. In Patent Document 2, a polymer seed particle having a weight average molecular weight of 10,000 to 300,000 dispersed in water is allowed to absorb a crosslinkable monomer and a polymerization initiator, and then the crosslinkable monomer is polymerized. Produced porous particles are disclosed. In Patent Document 3, a monomer having a plurality of hydrolyzable polymerizable functional groups is swelled or absorbed in a seed particle, the monomer is polymerized, and then an acid or alkali treatment is performed. Hollow porous polymer particles produced by removing the monomer polymer are disclosed. Patent Document 4 discloses porous particles having a number average particle diameter of 1 to 30 μm and a BET specific surface area of 0.1 to 80 m ² / g. Patent Document 5 discloses porous particles composed of a crosslinked (meth) acrylic ester resin.

The known porous particles disclosed in Patent Documents 2 to 5 and the like are all based on non-crosslinking organic seed particles or non-crosslinking organic polymers as a starting material, seed polymerization, polymer dissolution method, or polymer precipitation method. Thus, a porous structure is formed. Such particles have low solvent resistance because non-crosslinkable organic particles have a high raw material ratio. For this reason, when the resin or solvent and the particles are used in combination, problems such as an increase in viscosity of the compound due to swelling of the particles may occur.
JP 2003-183337 A JP 2000-191818 A JP 2006-131738 A JP 2007-219183 A JP 2002-265529 A

  If the surface is non-smooth particles such as porous particles having polysiloxane as a constituent member, an optical member that exhibits excellent characteristics can be realized without increasing the amount of particles added to the optical member, It is also expected to have excellent solvent resistance. However, as far as the applicant is aware, such particles have not been realized.

  In view of the above circumstances, an object of the present invention is to provide particles having polysiloxane as a constituent and having a non-smooth surface, and a method for producing the particles.

  As a result of intensive investigations by the present inventor to realize particles having an organic polymer and polysiloxane as constituent members and having a non-smooth surface, it is possible to realize surface non-smooth particles in which these constituent members are combined. It came.

  That is, the particles according to the present invention are characterized in that an organic polymer and an organopolysiloxane having no radically polymerizable unsaturated bond are complexed and a plurality of concave portions and / or convex portions are present on the surface. The “composite” in the present invention means that the organic polymer has entered between the organopolysiloxane skeletons. In addition, the “concave portion and / or convex portion” is a concave portion and / or convex portion that can be observed at a magnification of 5000 using a scanning electron microscope (SEM).

  Each of the recesses may have an irregular shape. The surface shape may be tufted.

  The organic polymer is preferably a polymer of a monofunctional monomer having one radical polymerizable double bond and a polyfunctional monomer having three or more radical polymerizable double bonds. The polyfunctional monomer may be an ester of a polyhydric alcohol and (meth) acrylic acid. The polyhydric alcohol may be one or more selected from pentaerythritol, dipentaerythritol, and trimethylolpropane.

The organopolysiloxane is preferably produced by condensing one or more silicon compounds represented by the following general formula (1). At least one kind of R ¹ of the silicon compound represented by the following general formula (1) is preferably an organic group having an epoxy group.
R ¹ _n Si (OR ² ) _4-n (1)
(In the general formula (1), R ¹ represents an organic group having no radically polymerizable unsaturated bond, n represents 1 or 2, and R ² represents hydrogen or an alkyl group having 1 to 6 carbon atoms. )

  The particle | grains which concern on this invention are suitable for the material of the resin composition containing resin. Using this resin composition, a light diffusion film, a light diffusion plate, and an antiglare film can be produced. Moreover, the particles according to the present invention are suitable as a material for conductive particles in which a conductor layer is formed at least partially.

  The method for producing particles according to the present invention comprises a seed particle production step for producing organopolysiloxane particles having no radically polymerizable unsaturated bond, a monofunctional monomer having one radically polymerizable double bond, and An absorption step of absorbing the polyfunctional monomer having three or more radical polymerizable double bonds into the organopolysiloxane particles, and a polymerization step of polymerizing the monofunctional monomer and the polyfunctional monomer. It is characterized by having.

  The polyfunctional monomer in the absorption step may be an ester of a polyhydric alcohol and (meth) acrylic acid, and the polyhydric alcohol is a kind selected from pentaerythritol, dipentaerythritol, and trimethylolpropane. Or two or more kinds are good.

In the seed particle production step, the organopolysiloxane particles may be produced by condensing the hydrolyzable silicon compound represented by the general formula (1), and at least ^one of R ¹ of the silicon compound is an epoxy. An organic group having a group is preferable.

  According to the particles according to the present invention having a plurality of concave portions and / or convex portions on the surface, an excellent optical member can be obtained even if the amount of the particles used is small. For example, a light diffusing film, a light diffusing plate and the like excellent in both light transmittance and luminance can be realized by the particles of the present invention.

  In addition, the particles according to the present invention comprising not only an organic polymer but also an organopolysiloxane can suppress swelling even when mixed with a resin. Therefore, an easy-to-handle resin composition can be produced.

(particle)
The particles according to the present invention have a plurality of concave portions and / or a plurality of convex portions on the surface thereof, and are composed of a composite of an organic polymer and an organopolysiloxane having no radically polymerizable unsaturated bond. Particles.

  The concave portions and / or convex portions present on the particle surface according to the present invention are a plurality of irregularly shaped concave portions, tufts, and the like. Here, “tufted” refers to an external shape in which a plurality of second particles smaller than the first particles are fused to the first particles.

  The overall shape of the particles according to the present invention ignoring the uneven portions is not particularly limited, such as a substantially spherical shape, a substantially needle shape, a substantially plate shape, a substantially scaly shape, a substantially saddle shape, a substantially saddle shape, but is generally substantially spherical. .

  The average particle diameter of the particles is preferably 0.1 to 200 μm, preferably 0.5 to 100 μm, and more preferably 1 to 50 μm. If the average particle diameter is in the range of 0.1 to 200 μm, the ratio between the organic polymer and the organopolysiloxane can be widely changed, so that the mechanical properties such as hardness and breaking strength of the particles according to the present invention are improved. It can be set appropriately. Further, when the average particle size is less than 0.1 μm, it becomes difficult to increase the ratio of the organic polymer, and when it exceeds 200 μm, the particles are likely to become unstable in the polymerization reaction for forming the organic polymer. The amount of the monomer described later becomes very large, and the particles according to the present invention tend to aggregate. In addition, the volume average particle diameter measured with the precision particle size distribution measuring apparatus using the Coulter principle is employ | adopted for the average particle diameter of particle | grains.

The variation coefficient in the particle diameter of the particles of the present invention is not particularly limited. However, since this coefficient of variation may be required to be small, it is preferably 20% or less, preferably 10% or less, and more preferably 5% or less. This coefficient of variation is a value obtained by applying the average particle diameter of the particles and the standard deviation of the particle diameter of the particles to the following equation (A).
Formula (A): Variation coefficient (%) of particles of the present invention = standard deviation of particle diameter / average particle diameter × 100

  The molecular weight of the organic polymer constituting the particles is not particularly limited, and exists between the organopolysiloxane skeletons constituting the particles. In order to confirm this presence, for example, a method of adding particles to a heated organic solvent such as toluene and confirming the mass change of the particles before and after the addition (the absence of mass change means that the organic polymer Means to exist between the siloxane skeletons); a method for confirming the presence of the organic polymer by observing the cut surface of the particles; the presence of functional groups derived from the organic polymer by infrared absorption spectrum analysis The method of confirming; etc. are mentioned.

  An organic polymer is not specifically limited, 1 type, or 2 or more types may be sufficient. Examples of organic polymers include (meth) acrylic polymers; styrene polymers; vinyl acetate polymers; cyclic olefin polymers; vinyl chloride polymers; vinylidene chloride polymers; And so on. These organic polymers may be used alone or in combination of two or more thereof, and may be partially modified with a functional group such as an amino group, an epoxy group, a hydroxyl group or a carboxyl group.

  A preferred organic polymer is a polymer of a monofunctional monomer having one radical polymerizable double bond and a polyfunctional monomer having three or more radical polymerizable double bonds. More preferred organic polymers are those in which the polyfunctional monomer of the organic polymer is an ester of a polyhydric alcohol and (meth) acrylic acid, and more preferred organic polymers are pentaerythritol, dipentaerythritol, and triethylene. One or more selected from methylolpropane is the polyhydric alcohol.

The organopolysiloxane constituting the particles is not particularly limited as long as it does not have a radical polymerizable unsaturated bond. Preferably, it is an organopolysiloxane obtained by hydrolytic condensation of one or more silicon compounds represented by the following general formula (1). As the silicon compound, a silicon compound having a group having an epoxy group is preferable.
R ¹ _n Si (OR ² ) _4-n (1)
(In the general formula (1), R ¹ represents an organic group having no radically polymerizable unsaturated bond, n represents 1 or 2, and R ² represents hydrogen or an alkyl group having 1 to 6 carbon atoms. )

Further, the ratio of the organopolysiloxane in the particles is not particularly limited. The amount of organopolysiloxane in which the amount of SiO ₂ is 0.1 to 80% by mass in the particles is common, and the amount is preferably 0.5 to 70% by mass, more preferably 1.0 to 60% by mass. .

(Method for producing particles)
A seed particle production process for producing organopolysiloxane particles having no radically polymerizable unsaturated bond, an absorption process for absorbing a predetermined monomer into the organopolysiloxane particles, and a predetermined process for absorbing the organopolysiloxane particles. If the method which has a polymerization process which polymerizes the monomer of this is used, the particle | grains based on this invention can be manufactured.

Seed particle manufacturing process:
In the seed particle manufacturing process, seed particles are manufactured. The “seed particles” are organopolysiloxane particles mainly composed of a three-dimensional network of siloxane bonds, and have non-radically polymerizable organic groups, but do not have radically polymerizable organic groups.

In the seed particle production process, it is preferable to produce seed particles by hydrolytic condensation of one or more hydrolyzable silicon compounds represented by the following general formula (1). This suitable method for producing seed particles is an embodiment of the method for producing seed particles used in the method for producing particles according to the present invention, and the seed particles used in the method of the present invention can also be produced by a known method.
R ¹ _n Si (OR ² ) _4-n (1)
(In the general formula (1), R ¹ represents an organic group having no radically polymerizable unsaturated bond, n represents 1 or 2, and R ² represents hydrogen or an alkyl group having 1 to 6 carbon atoms. )

R ¹ possessed by the silicon compound represented by the general formula (1) is one or two. Examples of R ¹ include an alkyl group such as a methyl group, an ethyl group, a hexyl group, and a decyl group; and an epoxy group such as a 3,4-epoxycyclohexyl group, a (3,4-epoxycyclohexyl) ethyl group, and a glycidoxypropyl group. A group having a group; an aryl group such as a phenyl group and a naphthyl group; and an aralkyl group such as a benzyl group. Of these examples, silicon compounds having a group having an epoxy group and an alkyl group as R ¹ are preferred.

Examples of R ² other than a hydrogen atom contained in the silicon compound represented by the general formula (1) include a methyl group and an ethyl group.

  Specific examples of the silicon compound represented by the general formula (1) where n = 1 are methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, hexyltrimethoxy. Silane, decyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, benzyltrimethoxysilane, naphthyltrimethoxysilane, 3,4-epoxybutyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane. Specific examples of the silicon compound represented by the general formula (1) where n = 2 are dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, Examples include 3-glycidoxypropylmethyldiethoxysilane and diphenylsilanediol.

  Hydrolysis condensation of the silicon compound is performed in a solvent. In this condensation, if necessary, a catalyst for hydrolytic condensation of the silicon compound is also contained in the solvent.

  As the solvent, a mixed solvent of water and one or more organic solvents is used. Here, it is preferable to use an organic solvent in which the silicon compound and water are dissolved, and the catalyst described later is dissolved if necessary; or an organic solvent in which micelles of water and the catalyst are uniformly dispersed. Examples of such an organic solvent include alcohols such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, t-butyl alcohol, pentyl alcohol, ethylene glycol, propylene glycol, and 1,4-butanediol; acetone, methyl ethyl ketone, and the like. Ketones; esters such as ethyl acetate; paraffins such as isooctane and cyclohexane; ethers such as dioxane and diethyl ether; aromatic hydrocarbons such as benzene and toluene. If an alcohol such as methanol, ethanol or propanol is selected, a large number of alkoxy groups such as methoxy group, ethoxy group and propoxy group can be present on the surface of the organopolysiloxane particles. An organic solvent that is incompatible with water or a catalyst can be used. In this case, a surfactant may be added to the solvent in order to uniformly disperse water and the catalyst.

  When a catalyst is used, ammonia; an ammonia generator such as urea capable of generating ammonia by heating; an aliphatic amine such as methylamine, ethylamine, propylamine, n-butylamine, dimethylamine, dibutylamine, trimethylamine, tributylamine; A basic catalyst such as an alicyclic amine such as cyclohexylamine; an aromatic amine such as benzylamine; a quaternary ammonium hydroxide such as tetramethylammonium hydroxide; an alkanolamine such as monoethanolamine, diethanolamine, or triethanolamine; Among these, ammonia, an aliphatic amine, an aromatic amine, and an alkanolamine are preferable because the particle size of the seed particles can be easily controlled. Further, from the viewpoint of easily reducing the remaining amount of the catalyst in the obtained seed particles, ammonia having a low boiling point and an aliphatic amine having 1 to 4 carbon atoms are preferable, and ammonia excellent in promoting hydrolysis condensation is particularly preferable.

  Adjusting the catalyst concentration may affect the shape and particle size of the seed particles to be prepared and the dissolved state of the silicon compound in the solvent. The catalyst concentration in the solvent is usually 0.001 mol / L or more and 10 mol / L or less, and preferably 0.01 mol / L or more and 1 mol / L or less. If the amount is less than 0.001 mol / L, the catalytic effect for increasing the hydrolysis reaction rate may not be obtained. If the amount exceeds 10 mol / L, the particle size distribution of the obtained seed particles may be widened.

  When the condensation of the silicon compound is performed, the silicon compound is added to the solvent. The addition mode at this time is not particularly limited, and various methods can be employed. For example, (1) A method of adding a silicon compound to a solvent in a lump and stirring, (2) A method of adding a silicon compound to the solvent in several portions while stirring the solvent, (3) A stirring of the solvent While, a method of continuously adding a silicon compound, (4) a method of previously preparing an organic solvent containing a silicon compound, and adding this organic solvent by any one of the methods (1) to (3), It is.

  In addition, water and a catalyst to be used are also added to an organic solvent or a solvent (consisting of water and an organic solvent). The addition mode at this time is also not particularly limited, and various methods can be employed. For example, there are a method of adding all at once, a method of adding in several times, and a method of adding continuously.

  5-50 degreeC is preferable, as for the temperature at the time of producing the hydrolytic condensation reaction of a silicon compound, 10-40 degreeC is more preferable, and 15-35 degreeC is still more preferable. If it is less than 5 ° C, the hydrolysis and condensation may not proceed easily. If it exceeds 50 ° C, the catalyst or solvent may volatilize and the reaction may not proceed easily, or the particles may aggregate.

  The reaction time for the hydrolysis condensation is preferably 30 minutes or longer, preferably 1 hour or longer, and more preferably 2 hours or longer. Further, this time is preferably 100 hours or less, preferably 20 hours or less, and more preferably 10 hours or less. If the reaction time is 30 minutes or more, the hydrolytic condensation of the silicon compound proceeds sufficiently, and if it is 100 hours or less, the hydrolytic condensation can proceed without causing coalescence or aggregation of the seed particles. .

  Under the above conditions, an emulsion in which seed particles are dispersed can be obtained. The emulsion may contain coarse seed particles. If it is necessary to remove the coarse particles, the emulsion can be removed by a filter. Coarse seed particles can be removed by using a filter having an opening larger than the average particle diameter of the seed particles by 1 μm or more. The filter may be a mesh having voids.

  The shape of the seed particles in the obtained emulsion is usually a spherical shape or a substantially spherical shape that is energetically stable in the particle formation process. The shape of the particles according to the present invention is determined by the shape of the seed particles. For example, if the seed particle is a perfect sphere or a substantially spherical shape, the overall shape of the particle according to the present invention ignoring the uneven portion is a substantially spherical shape.

  The average particle size of the seed particles is not particularly limited. The thickness is usually 0.1 to 100 μm, preferably 0.3 to 50 μm, and more preferably 0.5 to 30 μm. If the average particle size of the seed particles is less than 0.1 μm, the seed particles may not be able to sufficiently absorb the monomer. If the average particle size exceeds 100 μm, the seed particles will settle during the production process. Thus, seed particle aggregates are easily formed. As the average particle size of the seed particles, the volume average particle size measured with a precision particle size distribution measuring apparatus using the Coulter principle is adopted.

The variation coefficient of the particle diameter of the seed particles is not particularly limited, but it is desirable that the variation coefficient is small in order to produce homogeneous particles according to the present invention. Therefore, the coefficient of variation is preferably 20% or less, preferably 10% or less, and more preferably 5% or less. By applying the standard deviation of the volume-based particle size distribution measured simultaneously with the measurement of the average particle size and the average particle size to the following equation (B), the variation coefficient of the seed particles can be calculated.
Formula (B): Variation coefficient (%) of seed particles = standard deviation / average particle diameter × 100

Absorption process:
In the absorption step, the monomer that becomes the organic polymer raw material is absorbed in the seed particles. The absorption may be the addition of the monomer to the seed particles. However, from the viewpoint of the production efficiency of the particles according to the present invention, the emulsion obtained in the seed particle production step and the simple substance are used. Mix with the emulsion containing the polymer. The absorption process for mixing the monomer emulsion will be described in detail below.

  A monomer emulsion is an emulsion solvent, an emulsifier, a monomer (“monomer” is a general term for “monofunctional monomer” and “polyfunctional monomer”, the same shall apply hereinafter), and polymerization initiation. Contains agents. In addition, additives such as a chain transfer agent, an ultraviolet absorber, a flame retardant, and an antioxidant may be contained in the monomer emulsion as necessary.

  As the emulsion solvent, inexpensive water is preferably used. Although the usage-amount of an emulsion solvent is not specifically limited, When the monomer emulsion whole quantity is 100 mass parts, it is 20-70 mass parts.

  The emulsifier is used to enhance the dispersion of the monomer in the monomer emulsion and to efficiently absorb the monomer in the seed particles in the absorption process. Here, those selected from known surfactants such as anionic surfactants, cationic surfactants, zwitterionic surfactants, nonionic surfactants, and polymer surfactants can be used as emulsifiers. . Using one or more surfactants selected from anionic surfactants and nonionic surfactants improves the absorbability of the monomer and improves the dispersibility of the seed particles in the solvent. In particular, an anionic surfactant having excellent dispersibility of particles in the polymerization step described in detail later is preferable.

  Examples of the anionic surfactant include alkyl sulfate salts such as ammonium dodecyl sulfate, sodium dodecyl sulfate, potassium dodecyl sulfate, ammonium lauryl sulfate, sodium lauryl sulfate; sodium sulforicinoate; alkyl such as sulfonated paraffin alkali metal salt Sulphonate; alkyl aryl sulfonate such as sodium dodecylbenzene sulfonate and alkali metal sulfate of alkali phenol hydroxyethylene; alkyl naphthalene sulfonate; naphthalene sulfonic acid formalin condensate; sodium laurate, triethanolamine oleate, triethanolamine abiate Fatty acid salts of polyoxyalkyl ether sulfates; Polyoxyethylene carboxylic acid ester sulfuric ester salts, polyoxyethylene phenyl ether sulfate; and the like.

  Examples of the cationic surfactant include dialkyldimethylammonium salts, ester-type dialkylammonium salts, amide-type dialkylammonium salts, and dialkylimidazolinium salts.

  Examples of amphoteric surfactants include alkyldimethylaminoacetic acid betaines, alkyldimethylamine oxides, alkylcarboxymethylhydroxyethylimidazolinium betaines, alkylamidopropylbetaines, alkylhydroxysulfobetaines, N-tetradecyl-N, N-betaine types. Is mentioned.

  Nonionic surfactants include, for example, polyoxyethylene ethers such as polyoxyethylene alkyl ethers and polyoxyethylene alkyl aryl ethers; polyols and fatty acids such as sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and monolaurate of glycerol. And polyoxyethyleneoxypropylene copolymers; condensation products of ethylene oxide and fatty acid amines, amides or acids (boric acid, phosphoric acid, etc.).

  Examples of the polymeric surfactant include polyvinyl alcohol and modified products thereof; poly (meth) acrylates such as sodium poly (meth) acrylate, potassium poly (meth) acrylate, and ammonium poly (meth) acrylate Polymers; hydroxyl group-containing polymers such as poly (meth) acrylate hydroxyethyl and poly (meth) acrylate hydroxypropyl; polyvinylpyrrolidone and the like; copolymers containing constituent monomers of these polymers .

  The amount of the emulsifier used is preferably 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, with respect to 100 parts by mass of the total amount of the monofunctional monomer and polyfunctional monomer. It is more preferable in it being 0.1-2 mass parts. When the amount of the emulsifier used is less than 0.01 parts by mass, the dispersion of the monomer may become unstable. On the other hand, when the amount exceeds 10 parts by mass, side reactions may occur in the polymerization step.

  The monofunctional monomer is a monomer having one radical polymerizable double bond, and one or two or more monofunctional monomers are preferably selected.

  Monofunctional monomers include, for example, monomers having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate; methoxypolyethylene glycol (meta ) A monomer having a polyethylene glycol component such as acrylate; butyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isoamyl acrylate, lauryl (meth) acrylate, benzyl methacrylate, Alkyl (meth) acrylates such as tetrahydrofurfuryl methacrylate; fluorine atom content such as trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, pentanefluoropropyl (meth) acrylate, octafluoroamyl (meth) acrylate, etc. (Meth) acrylate; Aromatic vinyl compounds such as styrene, α-methylstyrene, vinyl tolman, α-chlorostyrene, 0-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-ethylstyrene; cyclic olefins; vinyl chloride, vinylidene chloride, etc. Olefin chloride: glycidyl (meth) acrylate, (meth) acrylic acid, (meth) acrylamide, (meth) acrylonitrile, etc. are preferably used.

  The amount of the monofunctional monomer used is preferably 20 to 90 parts by mass and preferably 30 to 80 parts by mass with respect to 100 parts by mass of the total amount of the monofunctional monomer and the polyfunctional monomer. More preferably, it is 50-70 mass parts.

  The polyfunctional monomer is a monomer having three or more radical polymerizable double bonds. By using one type or two or more types of polyfunctional monomers, the particles according to the present invention having a plurality of concave portions and / or convex portions on the surface can be produced.

  In the monomer emulsion preparation step, one or more known polyfunctional monomers can be used. Examples of the polyfunctional monomer include trimethylolpropane tri (meth) acrylate and tetramethylolmethane. Methylol esters such as tri (meth) acrylate and tetramethylolpropanetetra (meth) acrylate; erythritol esters such as pentaerythritol triacrylate, pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate; allyl esters such as diallyl phthalate; And allyl isocyanurate and derivatives thereof.

  It is preferable to use one or more polyfunctional monomers selected from esters of polyhydric alcohols and (meth) acrylic acid. A more preferred polyfunctional monomer is a polyfunctional monomer in which the polyhydric alcohol constituting the ester is one or more selected from pentaerythritol, dipentaerythritol, and trimethylolpropane.

  The surface shape of the particles according to the present invention varies depending on the number of radical polymerizable double bonds of the polyfunctional monomer. For example, when dipentaerythritol hexaacrylate having six radically polymerizable double bonds is used, a plurality of irregularly shaped recesses are present on the surface of the particle according to the present invention. When pentaerythritol tetraacrylate having a radical polymerizable double bond is used, the surface shape of the particle according to the present invention is tufted, and pentaerythritol triacrylate having three radical polymerizable double bonds is used. In this case, the surface shape of the particles according to the present invention is a tuft, and the convex portions constituting the tuft are smaller than when pentaerythritol tetraacrylate is used.

  The amount of the polyfunctional monomer used is preferably 10 to 80 parts by mass and preferably 20 to 70 parts by mass with respect to 100 parts by mass of the total amount of the monofunctional monomer and the polyfunctional monomer. More preferably, it is 30-50 mass parts.

  As the polymerization initiator, a known polymerization initiator for radical polymerization such as one or two or more peroxide polymerization initiators and azo polymerization initiators may be used. Examples of peroxide polymerization initiators include benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, benzoyl peroxide, orthomethoxybenzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, Examples include cyclohexanone peroxide, t-butyl hydroperoxide, and diisopropylbenzene hydroperoxide. Examples of the azo polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), and 2,2′-azobis (2,3-dimethyl). Butyronitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,3,3-trimethylbutyronitrile), 2,2′-azobis (2-isopropylbutyronitrile) Nitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2- (carbamoylazo) isobutyronitrile, Examples include 4,4′-azobis (4-cyanovaleric acid), dimethyl-2,2′-azobisisobutyrate, and the like.

  The amount of the polymerization initiator used is preferably 0.01 parts by mass to 10 parts by mass with respect to 100 parts by mass of the total amount of monomers (monofunctional monomer and polyfunctional monomer). It is preferable that it is -5 mass parts.

  In preparing the monomer emulsion, a high-speed stirrer such as a homomixer, an ultrasonic homogenizer, or a line mixer may be used.

  As described above, the monomer is absorbed by the seed particles by mixing the emulsion obtained in the seed particle manufacturing process and the monomer emulsion. The amount of the monomer emulsion used at this time may be an amount such that the total amount of monomers in the emulsion is 0.01 to 100 times the mass of the silicon compound used in the seed particle preparation step, The amount is preferably 0.1 to 50 times, and more preferably 0.5 to 30 times. When it is smaller than 0.01 times, the amount of monomer absorbed in the seed particles is reduced, and the surface of the particles according to the present invention may not be uneven. On the other hand, when it exceeds 100 times, the seed particles may not be able to completely absorb the monomer, and in this case, the monomer that has not been absorbed in the subsequent polymerization step is between the particles according to the present invention. Causes aggregation.

  When mixing the emulsion and the monomer emulsion, (1) a method in which the monomer emulsion is added to the emulsion in a lump and mixed, and (2) the monomer is divided into several times. Any method such as a method of adding to an emulsion and mixing, (3) a method of continuously adding an arbitrary amount of monomer emulsion to the emulsion, and mixing them can be adopted.

  If the particle diameter of the seed particle is increased by microscopic observation, it can be determined that the monomer has been absorbed by the seed particle.

Polymerization process:
In the polymerization step, the monomer absorbed in the seed particles is polymerized by radical polymerization. As the polymerization method at this time, a polymerization method such as a thermal polymerization method or a photopolymerization method is selected depending on the type of the polymerization initiator contained in the monomer emulsion.

  The polymerization temperature when the monomer is polymerized is preferably 40 to 100 ° C, more preferably 50 to 90 ° C. When the said reaction temperature is less than 40 degreeC, a polymerization degree becomes low and the mechanical characteristic of the obtained particle | grains may become inadequate. On the other hand, when the temperature exceeds 100 ° C., the particles according to the present invention tend to aggregate in the polymerization process.

  The time for polymerization should be set appropriately. If the polymerization time is too short, the degree of polymerization will be low, and if it is too long, the particles according to the present invention will agglomerate with each other. Therefore, it may be 5 to 600 minutes, and 10 to 300 minutes. And preferred.

(Use of particles)
The particles according to the present invention can be used as a resin composition containing a resin. The particles according to the present invention can be employed as a material for optical members because swelling due to resin is suppressed and light diffusibility is excellent. This resin composition is not particularly limited as long as it contains the particles and resin according to the present invention. In other words, resin compositions that contain solvents, curing agents, crosslinking agents, curing catalysts, pigments, dyes, plasticizers, dispersants, polymerization stabilizers, antioxidants, fluorescent brighteners, ultraviolet absorbers, antistatic agents, etc. It corresponds to a thing.

  The amount of the particles according to the present invention in the resin composition is appropriately set. Usually, it is 5-90 mass% in a resin composition.

  The resin for preparing the resin composition is not particularly limited. When preparing a resin composition for producing an optical member such as a light diffusing film or a light diffusing plate, the resin is selected according to properties such as transparency, resin fine particle dispersibility, light resistance, moisture resistance and heat resistance. Select use.

  Examples of the resin for preparing the resin composition include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, tert- (meth) acrylate It is a copolymer of one or more selected from butylcyclohexyl, lauryl (meth) acrylate, isobornyl (meth) acrylate, stearyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. (Meth) acrylic resin; (meth) acrylic urethane resin; urethane resin; polyvinyl chloride resin; polyvinylidene chloride tree Fats; Melamine resins; Styrene resins; Alkyd resins; Phenol resins; Epoxy resins; Polyester resins; (Meth) acrylic silicone resins, alkylpolysiloxane resins, silicone resins, silicone alkyd resins, silicones Examples thereof include modified silicone resins such as urethane resins, silicone polyester resins, and silicone acrylic resins; and fluorine resins such as polyvinylidene fluoride and fluoroolefin vinyl ether polymers. These resins may be curable resins such as thermosetting resins, hot-air curable resins, ultraviolet curable resins, and electron beam curable resins.

  In addition to the above resins, organic binder resins such as ethylene-propylene copolymer rubber, polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber; silica sol, alkali silicate, silicon alkoxide, their condensates, phosphate, etc. Inorganic binders may be used. In addition, when the polyfunctional isocyanate compound and the component having a hydroxyl group are contained in the resin, a crosslinked structure is formed by the polyfunctional isocyanate compound and the component having a hydroxyl group, so that moisture resistance, flexibility, Properties such as durability are further improved.

  When a solvent is included in the resin composition, coating of the resin composition becomes easy. According to the use of the resin composition, one kind or two or more kinds of solvents are appropriately selected. Examples of the solvent include aromatic solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as hexane and heptane; alcohols such as isopropyl alcohol, n-butyl alcohol, propylene glycol methyl ether, and dipropylene glycol methyl ether. Solvents; ester solvents such as butyl acetate, ethyl acetate, and cellosolve acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; dimethylformamide.

  The optical member manufactured using the resin composition is, for example, an optical member formed only of the resin composition; an optical member having a transparent sheet and a light diffusion layer formed of the resin composition on the surface Member; etc. are mentioned.

  FIG. 1 is a cross-sectional view illustrating an example of an optical member formed of only a resin composition. The optical member 1 shown in FIG. 1 has a film shape or a plate shape, and particles 3 according to the present invention are dispersed in a resin 2. The particles 3 diffuse light. The thickness and size of the optical member 1 are appropriately determined according to the application. Irregularities may be formed on the surface of the optical member 1, or the surface thereof may be flat. When the unevenness is formed, the light diffusibility of the optical member 1 is improved, which is preferable. In addition, the optical member 1 can be manufactured if the said resin composition is extrusion-molded and cast-molded.

  FIG. 2 is a cross-sectional view showing an example of an optical member having a transparent sheet and a light diffusion layer formed of a resin composition on the sheet surface. The optical member 5 shown in FIG. 2 has the base material sheet 8 and the light diffusion layer A formed on the surface of the base material sheet 8. The light diffusion layer A includes a layer of the resin composition.

  The base sheet 8 may be selected from general optical member sheets. Examples of the material of the sheet include glass; polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); triacetyl cellulose; olefin-based polymers such as cyclopolyolefin and amorphous polyolefin; polymethyl methacrylate and lactone ring. (Meth) acrylic resin-based polymer such as (meth) acrylate having polystyrene; Polystyrene; Polycarbonate; Polyvinyl acetal such as butyral resin; Polyaryl ether-based resin and the like. The thickness of the base sheet is determined according to required characteristics such as warpage due to heat shrinkage, flexibility, rigidity, and mechanical strength. When making the optical member 5 into a film form, it is preferable that the lower limit of the base material sheet 8 is 10 μm or more from the viewpoints of suppressing warpage due to heat shrinkage and the like and improving the handleability and strength. On the other hand, the thickness of the base material sheet 8 when the optical member 5 is formed into a film is usually less than 300 μm. In addition, the thickness of the base sheet 8 when the optical member 5 is plate-shaped is preferably such that the base sheet 8 itself does not bend and the optical member 5 does not bend. The following is normal.

  The haze of the base sheet 8 is preferably 0% or more and 20% or less, more preferably 0% or more and 10% or less, and further preferably 0% or more and 5% or less. The total light transmittance of the base sheet is preferably 70% or more and 100% or less, more preferably 80% or more and 100% or less. Haze and total light transmittance are values measured by a measuring method based on JIS K7105 using a turbidimeter such as “NDH-1001DP” manufactured by Nippon Denshoku Industries Co., Ltd.

  The light diffusion layer A can be formed by applying the resin composition to the base sheet and then drying it. The light diffusion layer A has a function of sufficiently diffusing incident light. The thickness of the light diffusion layer A is generally 1 μm to 100 μm. If the light diffusion layer A is less than 1 μm, the light incident on the light diffusion layer A may not be sufficiently diffused. If the thickness of the light diffusion layer A exceeds 100 μm, the light diffusion layer A passes through the light diffusion layer. The amount of light may decrease. The light diffusion layer A may be either a single layer or two or more layers, and in the case of two or more layers, it is preferable that at least one layer is formed of the resin composition.

  In addition, the thickness of the light-diffusion layer A measures the thickness of the light-diffusion layer A in five places arbitrarily selected in the optical member 1, and makes those average value the thickness of the light-diffusion layer A. Specifically, a part of the optical member 1 is embedded and solidified with an epoxy resin, and then cut into a thin piece in the cross-sectional direction of the optical member 1 with a microtome, and this is observed as a sample with a transmission electron microscope. And the thickness of the light-diffusion layer A in an electron microscope image is measured, and let the average value of a measured value be the thickness of the light-diffusion layer A. FIG.

  Irregularities may be formed on the surface of the light diffusion layer A, or the surface may be flat. When the surface of the light diffusing layer A is uneven, it is preferable that at least a part of the convex portions formed on the surface of the light diffusing layer A is based on the presence of the particles 7 according to the present invention.

  An optical member molded only with the resin composition and an optical member having a light diffusion layer are used as, for example, a constituent member of a backlight unit of a liquid crystal display device in a mobile phone, a PDA terminal, a digital camera, a television, a computer, etc. Is done. A backlight unit is disposed behind the liquid crystal display panel. When light from the backlight unit is irradiated, an image is displayed on the liquid crystal display panel. In addition, the optical member can be used for applications such as a plasma display device, an electroluminescence display device, and the like that expand the viewing angle.

  FIG. 3 is an exploded view illustrating a configuration example of the backlight unit, and a liquid crystal panel is disposed in the upward direction of the figure. The backlight unit 9 includes a light source 13, a reflection sheet 14 that plays a role of reflecting light emitted downward from the light source 13, a light diffusion plate 12 that diffuses light from the light source 13, and a light diffusion plate The light diffusion film 11 which further diffuses the light which passed 12 and the prism sheet 10 which condenses the light which passed the light diffusion film 11 to a front direction are provided. Note that the backlight unit 9 shown in FIG. 3 is merely an example of a known backlight unit, and a plurality of light diffusion films are usually used in the known backlight unit.

  A light diffusing film that can be applied to a constituent member such as a backlight unit by appropriately determining the thickness, dimensions, and constituent members of both the optical member formed only from the resin composition and the optical member having a light diffusing layer. Can be used for light diffusion plate. The haze of the optical member used in this manner is preferably 75% or more, more preferably 80% or more, still more preferably 85% or more, preferably 95% or less, more preferably 90% or less. Further, the total light transmittance is preferably 60% or more, more preferably 65% or more, and further preferably 70% or more. The haze and total light transmittance can be measured by a measuring method based on JIS K7105 using a turbidimeter (for example, “NDH-1001DP” manufactured by Nippon Denshoku Industries Co., Ltd.).

  The optical member manufactured using the resin composition can be used in addition to the light diffusion film and the light diffusion plate. For example, if the film-like optical member is laminated on the outermost surface of a display panel such as a liquid crystal display device, the laminated optical member exhibits a function as an antiglare film.

  The particles according to the present invention have uses as particles for conductive particles as uses other than the resin composition and the optical member. The conductive particles include particles according to the present invention and a conductor layer formed on the particle surface. Since the conductive particles are composed of the particles according to the present invention, the conductive particles have hardness and breaking strength for maintaining a constant distance between a pair of electrically connected electrode substrates. Therefore, the conductive particles can be used as electrical connection materials for electronics such as liquid crystal display boards, LSIs, and printed wiring boards.

  The said conductor layer should just be formed in at least one part of the surface of the particle | grains concerning this invention. The metal constituting the conductor layer is not particularly limited. Examples of the metal include nickel, gold, silver, copper, indium, and alloys thereof, and nickel, gold, and indium having high conductivity are preferable. Although the thickness of a conductor layer is not specifically limited, It is good in it being 0.01-5.0 micrometers. The conductor layer may be one layer or two or more layers, and in the case of two or more layers, each conductor layer may be made of different metals.

  The conductor layer may be formed by a known method, and examples thereof include an electrolytic plating method, a chemical plating method, a coating method, and a PVD (vacuum deposition, sputtering, ion plating, etc.) method.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented within a range that can meet the purpose described above and below. All of which are within the scope of the present invention.

Example 1
Preparation of organopolysiloxane particles:
A four-necked flask equipped with a condenser, a thermometer, and a dripping port is charged with 526 parts by mass of ion-exchanged water, 1.6 parts by mass of 25% by mass ammonia water, and 118 parts of methanol. -Radical polymerizable unsaturated bond by adding 30 parts by mass of (3,4-epoxycyclohexyl) ethyltrimethoxysilane from the dropping port and hydrolytic condensation of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane An emulsion of organopolysiloxane particles having no odor was prepared. The preparation time of this emulsion was 2 hours from the start of hydrolysis condensation. A part of the prepared emulsion was collected, and the average particle diameter of the organopolysiloxane particles measured by “Coulter Multisizer” manufactured by Beckman Coulter was 2.02 μm.

Preparation of monomer emulsion:
To an emulsifier solution prepared by 2.5 parts by mass of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (Daiichi Kogyo Seiyaku Co., Ltd. “Hytenol NF-08”) and 175 parts by mass of ion-exchanged water as an emulsifier, 60 parts by mass of styrene as a monofunctional monomer, 40 parts by mass of dipentaerythritol hexaacrylate as a polyfunctional monomer, 2,2′-azobis (2,4-dimethylvaleronitrile) as a cross-linking agent (Wako Pure) 2 parts by mass of “V-65” manufactured by Yakuhin Kogyo Co., Ltd. is added, and the compound added at 6000 rpm for 5 minutes is dispersed in an emulsifier solution using a “TK homomixer” manufactured by Tokushu Kika Kogyo Co., Ltd. A body emulsion was prepared.

Monomer absorption into organopolysiloxane particles:
The emulsion was mixed with the monomer emulsion and stirred. Two hours after the mixing of the monomer emulsion, a part of the mixture was collected and observed with a microscope. As a result, the organopolysiloxane particles absorbed the components of the monomer emulsion and enlarged.

Monomer polymerization:
The mixed solution of the emulsion and the monomer emulsion is placed in a nitrogen atmosphere and heated to 65 ° C., and then the temperature after the temperature increase is maintained for 2 hours, thereby being absorbed by the organopolysiloxane particles. The monomer was radically polymerized.

  The cake obtained from the liquid after polymerization by solid-liquid separation was washed with ethanol, and further vacuum-dried at 80 ° C. for 12 hours to obtain particles of Example 1. The average particle diameter of the particles of Example 1 measured by a particle size distribution measuring apparatus (“Coulter Multisizer” manufactured by Beckman Coulter, Inc.) was 3.5 μm, and the variation coefficient of the particle diameter was 2.7%. Further, the particles of Example 1 were observed with an SEM (scanning electron microscope “S-3500N” manufactured by Hitachi, Ltd.). FIG. 4 is a photograph obtained by observing the particles of Example 1 with a SEM at a magnification of 5000, FIG. 5 is a photograph observed at a magnification of 10,000, and FIG. 6 is a photograph observed at a magnification of 20000. 4 to 6, it can be confirmed that a plurality of irregularly shaped recesses exist on the particle surface of Example 1.

(Example 2)
The particles of Example 2 were prepared in the same manner as Example 1 except that 80 parts by mass of styrene and 20 parts by mass of dipentaerythritol hexaacrylate were used. The average particle size of the particles of Example 2 was 3.2 μm, and the variation coefficient of the particle size was 4.1%. When the particle surface of Example 2 was observed by SEM, the presence of a plurality of irregularly shaped recesses was confirmed in the same manner as the particles of Example 1.

(Example 3)
The particles of Example 3 were prepared in the same manner as in Example 1 except that 40 parts by mass of dipentaerythritol hexaacrylate was changed to 40 parts by mass of pentaerythritol tetraacrylate. The average particle size of the particles of Example 3 was 4.2 μm, and the variation coefficient of the particle size was 3.9%. 7 is a photograph obtained by observing the particles of Example 3 with a SEM at a magnification of 5000, FIG. 8 is a photograph observed with a magnification of 15000, and FIG. 9 is a photograph observed with a magnification of 25000. 7-9, it can confirm that the surface shape of the particle | grains of Example 3 was tufted.

Example 4
The particles of Example 4 were prepared in the same manner as in Example 1 except that 40 parts by mass of dipentaerythritol hexaacrylate was changed to 40 parts by mass of pentaerythritol triacrylate. The average particle size of the particles of Example 4 was 3.8 μm, and the variation coefficient of the particle size was 4.0%. FIG. 10 is a photograph obtained by observing the particles of Example 4 with a SEM at a magnification of 5000, FIG. 11 is a photograph observed at a magnification of 15000, and FIG. 12 is a photograph observed at a magnification of 25000. 10-12, it can confirm that the surface shape of the particle | grains of Example 4 was tufted. Moreover, the convex part of the particle | grain surface of Example 4 was smaller than the convex part of the particle | grain surface of Example 3. FIG.

(Comparative example)
In the preparation of the organopolysiloxane particles, 30 parts by mass of 3-methacryloxypropyltrimethoxysilane was used instead of 30 parts by mass of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and a radical polymerizable unsaturated bond (radical Organopolysiloxane particles having a polymerizable vinyl group) were prepared. In preparation of the monomer emulsion, 40 parts by mass of ethylene glycol dimethacrylate was used instead of 40 parts by mass of dipentaerythritol hexaacrylate. Except for these, Comparative Example particles were prepared in the same manner as in Example 1. The average particle diameter of the organopolysiloxane particles obtained in the process of preparing these particles was 1.95 μm. The average particle size of the comparative example particles was 3.4 μm, and the coefficient of variation in particle size was 2.9%. And the particle | grains of the comparative example confirmed by SEM observation were the perfect spherical shape with the smooth surface.

(Reference Example 1)
The particles of Reference Example 1 were prepared by the same method as disclosed in Example 5 of JP-A No. 2000-191818. That is, the particles of Reference Example 1 were prepared as follows. 3.6 parts by mass of polyvinylpyrrolidone having a weight average molecular weight of 30,000, 0.6 parts by mass of an anionic surfactant (“Aerosol OT” manufactured by Wako Pure Chemical Industries, Ltd.), 0.14 parts by mass of azobisisobutyronitrile, and ethanol 84 A mixed solution of parts by mass was prepared. 14 parts by mass of styrene was added dropwise to the mixture that was being stirred under a nitrogen stream. Thereafter, the mixture was heated to 60 ° C. and the reaction was allowed to proceed for 24 hours to prepare seed particles. After completion of the reaction, seed particles were isolated using a centrifuge and washed with methanol. 0.5 parts by mass of the seed particles, 50 parts by mass of ion-exchanged water, and 0.05 parts by mass of sodium lauryl sulfate were mixed to prepare a sheet particle dispersion, and 20 parts by mass of a 3% by weight aqueous polyvinyl alcohol solution was added to the dispersion. added. Next, an emulsion prepared separately from 5 parts by weight of divinylbenzene, 0.25 parts by weight of benzoyl peroxide having a water content of 25% by weight, 50 parts by weight of ion-exchanged water, and 0.1 parts by weight of sodium lauryl sulfate, The emulsion was added to the dispersion and stirred at 25 ° C. and 100 rpm for 24 hours to absorb the emulsion in the seed particles. Next, after substituting the seed particle atmosphere with nitrogen, particles of Reference Example 1 were prepared by polymerizing divinylbenzene absorbed into the seed particles under the conditions of 200 rpm stirring and 70 ° C. for 24 hours. And the particle | grains of the reference example 1 were isolate | separated using the centrifuge, and the particle | grains of the reference example 1 were wash | cleaned and centrifuged twice each in the order of ethanol, the mixed medium of ethanol and water, and water.

(Reference Example 2)
The particles of Reference Example 2 were prepared by the same method as disclosed in Example 1 of JP-A-2006-131738. That is, the particles of Reference Example 2 were prepared as follows. 80 parts by mass of ethylene oxide-modified trimethylolpropane triacrylate, 2.0 parts by mass of benzoyl peroxide, 200 parts by mass of water, and 3.3 parts by mass of polyoxyethylene phenyl ether sulfate salt were mixed for 5 minutes and mixed. 20 parts by mass of seed particles, which are polymethyl methacrylate particles having an average particle diameter of 2.9 μm as observed by an electron microscope, are added to the liquid, and the mixture is stirred at 50 ° C. for 30 minutes to absorb ethylene oxide-modified trimethylolpropane triacrylate. I let you. Thereafter, particles of Reference Example 2 were prepared by polymerizing ethylene oxide-modified trimethylolpropane triacrylate absorbed into the seed particles under conditions of 4.0 hours at 60 ° C. and 8 hours at 95 ° C. And the particle | grains of the reference example 2 were isolate | separated by suction filtration, the particle | grains of the reference example 2 were disperse | distributed to 10 mass% NaOH aqueous solution so that a density | concentration might be 20 mass%, and it heated at 90 degreeC after that for 2 hours. The dispersion was cooled, then neutralized with hydrochloric acid, and the particles of Reference Example 2 were separated by suction filtration and dried at 90 ° C. for 8 hours.

  As described later, a light diffusion film, a light diffusion plate, and an antiglare film were produced using the particles of Examples, Comparative Examples, and Reference Examples. Moreover, the characteristics of the manufactured light diffusion film and the like were evaluated.

The characteristics of the light diffusion film and the like were evaluated as follows.
(Total light transmittance)
A turbidimeter “NDH-1001DP” manufactured by Nippon Denshoku Industries Co., Ltd. was used, and measurement was performed in accordance with JIS K7105.

(Haze)
A turbidimeter “NDH-1001DP” manufactured by Nippon Denshoku Industries Co., Ltd. was used, and measurement was performed in accordance with JIS K7105.

(Luminance)
The luminance was measured using a luminance meter “BM-7” manufactured by Topcon Corporation. In this measurement, the atmosphere in the measurement chamber is set to a temperature of 25 ° C. and a humidity of 60% RH, and a direct type backlight unit for a 15-inch type liquid crystal display device (a cold cathode tube lamp has an intensity of 10,000 cd / m ^2). The measurement intensity of 231 mm in length and 321 mm in width was incorporated in the lamp intensity setting), and the luminance (cd / m ² ) at the center point of the measurement sample was measured. The measurement distance was 50 cm and the viewing angle was 1 °.

(Anti-glare)
A black film was pasted on the back of the sample, and a fluorescent lamp of 10,000 cd / m ² was projected from a distance of 2 m, and the degree of blur of the reflected image was evaluated according to the following criteria.
○: The outline of the fluorescent lamp could not be discriminated ×: The outline of the fluorescent lamp could be clearly confirmed

(Transparency definition)
Using a mapping measuring instrument (“ICB-1DD” manufactured by Suga Test Instruments Co., Ltd.) and an optical comb having a width of 0.5 mm, the transmission sharpness was measured according to JIS K7150.

(Character blur)
A sample is pasted on the surface of a liquid crystal monitor (15-inch XGA, TFT-TN system, front luminance 350 cd / m ² , front contrast 300 to 1, no surface AG) connected to a personal computer. Evaluation was made according to the criteria.
○: The outline of the character was not blurred at all.
X: The outline of the character was blurred and a strong sense of incongruity was felt

(Light diffusion film)
Particles (10 parts by mass of Example or Reference Example, 50 parts by mass of Comparative Example), 100 parts by mass of polyester polyol, 20 parts by mass of polyfunctional isocyanate (“Sumidule N320” manufactured by Sumika Bayer Urethane Co., Ltd.), and electric resistance A resin composition was prepared by mixing 2 parts by mass of the inhibitor. The prepared resin composition was applied to the surface of a transparent biaxially stretched polyester film (thickness: 100 μm) by a roll coating method. Thereafter, the polyester film was allowed to stand at room temperature for 1 hour and then dried at 80 ° C. for 2 hours to produce a light diffusion film. The thickness of the light diffusion layer (dry film of the resin composition) of the light diffusion film was 15 μm.

  In addition, in the resin composition preparation process using the particles of Reference Example 1 or 2, since the particles swelled and the viscosity of the resin composition increased, the resin composition could not be applied uniformly. .

  Table 1 shows the results of measuring the total light transmittance, haze, and luminance of the light diffusion film.

  From the above table, the light diffusing film using the particles of Examples 1 to 4 had a haze value equivalent to that using the particles of the comparative example, but the total light transmittance and luminance were significantly superior. I understand. In other words, even a light diffusion film with a small amount of particles according to the present invention can highly scatter light, so the results in the above table show the total light transmittance when using the particles according to the present invention. This demonstrates that the haze can be adjusted without reducing it. Moreover, this demonstration is the same also in contrast with the light-diffusion film using the particle | grains of Examples 1-4 and the light-diffusion film using the particle | grains of Reference Examples 1-2.

(Light diffusion plate)
Particles (0.1 parts by mass of Example or Reference Example, 0.5 parts by mass of Comparative Example), 100 parts by mass of polycarbonate resin (“Iupilon E2000FN” manufactured by Mitsubishi Engineering Plastics), phenol-phosphate-lactone Three parts mixed antioxidants ("Irganox 2215" manufactured by Ciba Specialty Chemicals) 0.05 parts by mass and 0.03 parts by mass of oxazole fluorescent whitening agent ("Ubitex OB" manufactured by Ciba Specialty Chemicals) Was supplied to a sheet extrusion molding machine equipped with a vent / gear pump / three-roll / two-roll pressure laminating apparatus and molded at a molding temperature of 280 ° C. to obtain a light diffusion plate (thickness 2 mm).

  In addition, when manufacturing the light diffusing plate using the particles of the reference example, deformation and melting of the used particles were observed.

  Table 2 shows the results of measuring the luminance of the light diffusion plate.

  From the said table | surface, it turns out that the brightness | luminance of the light diffusing plate using the particle | grains of Examples 1-4 was remarkably high compared with what used the particle | grains of a comparative example. The same applies to the comparison between the light diffusing plate using the particles of Examples 1 to 4 and the one using the particles of Reference Examples 1 and 2.

(Anti-glare film)
The particles (1 part by mass of the particles of the example or reference example, 3 parts by mass of the particles of the comparative example) and 20 parts by mass of toluene were sufficiently stirred and mixed. In the mixed solution, 40 parts by mass of an acrylic ionizing radiation curable resin, 2 parts by mass of a photopolymerization initiator (“Irgacure 907” manufactured by Ciba Specialty Chemicals), 23 parts by mass of methyl ethyl ketone, 2 parts by mass of ethylene glycol monobutyl ether, and leveling 0.5 parts by mass of an agent (“BYK320” manufactured by Big Chemie) was added and sufficiently stirred to prepare a resin composition. This resin composition was applied to one side of a 80 μm-thick triacetyl cellulose film (“Fujitack” manufactured by Fuji Photo Film Co., Ltd.) using a bar coater. The coating film was dried with a 80 ° C. tray, and then the resin composition was cured by irradiating 300 mJ / cm ² of ultraviolet rays using a high-pressure mercury lamp to obtain an antiglare film.

  In the production of the antiglare film using the particles of Reference Examples 1 and 2, when the resin composition was prepared, the particles swelled and the viscosity of the resin composition increased, so the resin composition was applied to the triacetyl cellulose film. It could not be applied uniformly.

  Table 3 shows the evaluation results of the antiglare property, transmission clarity and character blur of the antiglare film.

  From the said table | surface, it turns out that the glare-proof film using the particle | grains of Examples 1-4 was excellent in the permeation | transmission clarity and character blur compared with what used the particle | grains of a comparative example. Moreover, the anti-glare film using the particles of Examples 1 to 4 is superior in all of the anti-glare property, the transmission sharpness, and the character blur compared with those using the particles of Reference Examples 1 and 2. I understand that.

It is sectional drawing showing an example of the optical member which concerns on this invention. It is sectional drawing showing the other example of the optical member which concerns on this invention. It is an exploded view showing the structural example of a backlight unit. It is the photograph which observed the particle | grains of Example 1 with 5000 magnifications by SEM. It is the photograph which observed the particle | grains of Example 1 with 10,000 magnifications by SEM. It is the photograph which observed the particle | grains of Example 1 with 20000 magnification by SEM. It is the photograph which observed the particle | grains of Example 3 with 5000 magnifications by SEM. It is the photograph which observed the particle | grains of Example 3 by 15000 magnification by SEM. It is the photograph which observed the particle | grains of Example 3 by 25000 magnification by SEM. It is the photograph which observed the particle | grains of Example 4 with 5000 magnifications by SEM. It is the photograph which observed the particle | grains of Example 4 by 15000 magnification by SEM. It is the photograph which observed the particle | grains of Example 4 by 25000 magnification by SEM.

Explanation of symbols

A Light diffusing layer 1, 5 Optical member 2, 6 Resin 3, 7 Particle 8 Base material sheet 9 Backlight unit 10 Prism sheet 11 Light diffusing film 12 Light diffusing plate 13 Light source 14 Reflecting sheet

Claims (18)

  Particles in which an organic polymer and an organopolysiloxane having no radically polymerizable unsaturated bond are complexed to have a plurality of concave portions and / or convex portions on the surface.   The particle according to claim 1, wherein each of the recesses has an irregular shape.   The particle according to claim 1, wherein the surface has a tuft shape.   The organic polymer is a polymer of a monofunctional monomer having one radical polymerizable double bond and a polyfunctional monomer having three or more radical polymerizable double bonds. 4. The particle according to any one of 3 above.   The particle according to claim 4, wherein the polyfunctional monomer is an ester of a polyhydric alcohol and (meth) acrylic acid.   The particles according to claim 5, wherein the polyhydric alcohol is one or more selected from pentaerythritol, dipentaerythritol, and trimethylolpropane. The particle according to any one of claims 1 to 6, wherein the organopolysiloxane is produced by condensing one or more silicon compounds represented by the following general formula (1).
R ¹ _n Si (OR ² ) _4-n (1)
(In the general formula (1), R ¹ represents an organic group having no radically polymerizable unsaturated bond, n represents 1 or 2, and R ² represents hydrogen or an alkyl group having 1 to 6 carbon atoms. ) The particle according to claim 7, wherein at least ^one of R ¹ of the silicon compound represented by the general formula (1) is an organic group having an epoxy group.   The resin composition containing the particle | grains and resin of any one of Claims 1-8.   The light-diffusion film manufactured using the resin composition of Claim 9.   A light diffusing plate produced using the resin composition according to claim 9.   An antiglare film produced using the resin composition according to claim 9.   The electroconductive particle which has the particle | grains of any one of Claims 1-8, and the conductor layer formed in at least one part of this particle | grain. A seed particle production process for producing organopolysiloxane particles having no radically polymerizable unsaturated bond;
An absorption step of allowing the organopolysiloxane particles to absorb a monofunctional monomer having one radical polymerizable double bond and a polyfunctional monomer having three or more radical polymerizable double bonds;
And a polymerization step of polymerizing the monofunctional monomer and the polyfunctional monomer.   The method for producing particles according to claim 14, wherein the polyfunctional monomer in the absorption step is an ester of a polyhydric alcohol and (meth) acrylic acid.   The method for producing particles according to claim 15, wherein the polyhydric alcohol is one or more selected from pentaerythritol, dipentaerythritol, and trimethylolpropane. The particles according to any one of claims 14 to 16, wherein in the seed particle production step, the organopolysiloxane particles are produced by condensing a hydrolyzable silicon compound represented by the following general formula (1). Production method.
R ¹ _n Si (OR ² ) _4-n (1)
(In the general formula (1), R ¹ represents an organic group having no radically polymerizable unsaturated bond, n represents 1 or 2, and R ² represents hydrogen or an alkyl group having 1 to 6 carbon atoms. ) The method for producing particles according to claim 17, wherein at least ^one of R ¹ of the silicon compound represented by the general formula (1) is an organic group having an epoxy group.