JP5460262B2 - Method for producing irregular shaped resin particles, irregular shaped resin particles and light diffusing material - Google Patents

Description

  The present invention relates to a simple production method of deformed resin particles having excellent oil absorption and light diffusibility, deformed resin particles obtained by the production method, and a light diffusing material containing the deformed resin particles. More specifically, the present invention relates to a method for producing irregularly shaped resin particles, which can obtain the irregularly shaped resin particles very easily without requiring the hydrophobic liquid and the step of removing the hydrophobic liquid that were conventionally required when producing irregularly shaped resin particles. The present invention relates to an irregularly shaped resin particle obtained by the production method, and a light diffusing material containing the irregularly shaped resin particle.

  Vinyl resin particles are widely used in various fields as paint additives, cosmetic additives, toner additives, adhesives, light diffusing agents, liquid crystal spacers, binders, rheology modifiers, extenders, coating film performance improvers, etc. It has been. In particular, these resin particles are used as a light diffusing material, a cosmetic material, an organic pigment for paint, an organic pigment for paper coating, a carrier for diagnostic agents, and the like because of its excellent oil absorption and light diffusibility. Moreover, since these resin particles are usually obtained by suspension polymerization in an aqueous medium, the shape thereof is generally spherical.

  However, in recent years, in order to increase the whiteness and gloss of paints, etc., and to increase the functionality of diagnostic agents, further improvements in oil absorption and light diffusibility of vinyl resin particles are required. Therefore, the following deformed resin particles having a shape different from a true spherical shape have been proposed as vinyl resin particles that satisfy these requirements (Patent Documents 1 and 2).

JP 05-317688 A Japanese Patent Application Laid-Open No. 07-157672

  These irregular shaped resin particles are known to be excellent in oil absorption and light diffusibility because of their large specific surface area compared to true spherical resin particles.

  Patent Document 1 proposes a bowl-shaped deformed resin particle having one large concave portion at the center as a deformed resin particle, and describes that the deformed resin particle has excellent oil absorption. However, since the irregular resin particles are obtained by suspension polymerization of a monofunctional vinyl monomer and a polyfunctional vinyl monomer in an aqueous medium in the presence of a hydrophobic liquid such as liquid paraffin, the obtained irregular resin particles are It will contain a hydrophobic liquid that may adversely affect the product.

  Therefore, in order to remove the hydrophobic liquid, it is necessary to incorporate a complicated washing process in the manufacturing process in which the hydrophobic liquid is removed from the deformed resin particles with a solvent such as a lower alcohol capable of dissolving only the hydrophobic liquid. Moreover, in order to perform the said process, a comparatively expensive solvent must be used, and also a large-scale washing | cleaning installation, a drying installation, etc. are required. Therefore, the said process is not preferable at points, such as manufacturing cost.

  In Patent Document 2, a hollow non-spherical deformed resin particle having a hollow portion in the deformed resin particle and further having a large number of vent holes in the outer shell having irregularities is proposed. Similarly, it is described that the irregular shaped resin particles also have excellent oil absorption. However, as in the case of Patent Document 1, it is necessary to use a hydrophobic liquid such as normal hexane or normal heptane when producing the irregular shaped resin particles, and the same problem also applies to the invention described in Patent Document 2. Points are pointed out.

  Therefore, a hydrophobic liquid that has been necessary in the conventional production of irregular shaped resin particles and a simple production method of irregular shaped resin particles having excellent oil absorption and light diffusibility, which does not require the removal step thereof, and a production method thereof It is desired to provide deformed resin particles obtained by the above.

  Thus, according to the present invention, 100 parts by weight of a monofunctional vinyl monomer, 1 to 40 parts by weight of a polyfunctional vinyl monomer, and 1 to 100 parts by weight of a methacryl-modified silicone oil-based vinyl monomer are present in an aqueous medium in the absence of a hydrophobic liquid. There is provided a method for producing deformed resin particles characterized by polymerizing below.

Moreover, according to this invention, the unusual shape resin particle obtained by the said manufacturing method is also provided.
Furthermore, according to this invention, the light diffusable material containing the said unusual shaped resin particle is also provided.

According to the production method of the present invention, it is possible to obtain irregularly shaped resin particles very easily without the need for the hydrophobic liquid and the step of removing the hydrophobic liquid, which were conventionally required when producing irregularly shaped resin particles.
In the present invention, the irregular shaped resin particles can be more easily produced by using a specific methacryl-modified silicone oil-based vinyl monomer.
On the other hand, any one of a (meth) acrylic monofunctional vinyl monomer and a styrene monofunctional vinyl monomer is used as the monofunctional vinyl monomer, and a (meth) acrylic polyfunctional vinyl monomer and a styrenic polyfunctional monomer are used as the polyfunctional vinyl monomer. By using any one of the functional vinyl monomers, the irregular shaped resin particles can be more stably produced.

In the present invention, when the polymerization is suspension polymerization, the irregular shaped resin particles can be easily and safely produced while suppressing excessive heat generation and pressure increase during the polymerization.
In addition, by adjusting the amount of monofunctional vinyl monomer, polyfunctional vinyl monomer, and methacryl-modified silicone oil vinyl monomer, the deformed resin particles having two or more recesses on the surface of the deformed resin particles or having one recess in the center The bowl-shaped deformed resin particles can be easily made.

According to the production method of the present invention, irregular shaped resin particles can be appropriately obtained.
Moreover, the irregular shape resin particle which has the outstanding oil absorption can be obtained with the manufacturing method of this invention.
On the other hand, by the production method of the present invention, a bowl-shaped deformed resin particle having an extremely large average diameter of the recesses can be easily obtained.
Moreover, according to this invention, the light diffusable material which has the outstanding light diffusibility is also provided.

4 is an electron micrograph of uneven irregular shaped resin particles of Example 3. FIG. 2 is an electron micrograph of a bowl-shaped irregular resin particle of Example 1. FIG. 4 is an electron micrograph of true spherical resin particles of Comparative Example 3. It is the schematic of a bowl-shaped irregularly shaped resin particle.

In the present invention, odd-shaped resin particles are produced by polymerizing a monofunctional vinyl monomer, a polyfunctional vinyl monomer, and a methacryl-modified silicone oil-based vinyl monomer in an aqueous medium in the absence of a hydrophobic liquid.
Below, the manufacturing method of the irregular-shaped resin particle of this invention is demonstrated.

  In the present invention, the aqueous medium means an aqueous medium that may appropriately contain a water-soluble organic medium such as a lower alcohol as long as it does not affect the physical properties, production process, and the like of the shaped resin particles obtained.

  Further, the monofunctional vinyl monomer means a polymerizable monomer having one vinyl group, and one or two or more kinds of monofunctional vinyls are used as long as they do not affect the physical properties, production process, etc. of the deformed resin particles obtained. Monomers can be used.

Specific examples of the monofunctional vinyl monomer include (meth) acrylic acid and salts thereof, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, N-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meta (Meth) acrylic such as octyl acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate Monofunctional vinyl monomer;
Styrene monofunctional vinyl monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, chlorostyrene, vinyltoluene;
Examples include vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, vinyl acetate, acrylonitrile, methacrylonitrile, allyl alcohol, vinyl pyridine, vinyl benzoate, allyl benzoate, acrylamide, methacrylamide, N-vinyl pyrrolidone, etc. .
In the present invention, (meth) acryl means acryl or methacryl.

  In addition, since irregularly shaped resin particles can be polymerized stably, any one of (meth) acrylic monofunctional vinyl monomer and styrene monofunctional vinyl monomer is preferable as the monofunctional vinyl monomer, and methyl methacrylate, methacrylic acid Any one of butyl, butyl acrylate, and styrene is more preferable.

  In the present invention, a polyfunctional vinyl monomer is used because the resulting polymer can be more easily deformed. Here, the polyfunctional vinyl monomer means a polymerizable monomer having two or more vinyl groups, and one or two or more kinds of polyfunctional monomers are used as long as the physical properties of the obtained irregular shaped resin particles, the production process, etc. are not affected. Vinyl monomers can be used.

Specific examples of the polyfunctional vinyl monomer include polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-butylene glycol diacrylate, neopentyl glycol diacrylate, polypropylene diacrylate, and 2,2′-bis. Diacrylate polyfunctional vinyl monomers such as (4-acryloxypropyloxyphenyl) propane and 2,2′-bis (4-acryloxydiethoxyphenyl) propane;
Triacrylate-based polyfunctional vinyl monomers such as trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane triacrylate;
Tetraacrylate polyfunctional vinyl monomers such as ditrimethylolpropane tetraacrylate, tetramethylolmethane tetraacrylate, pentaerythritol tetraacrylate;
Ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6-hexane glycol dimethacrylate, neopentyl glycol Dimethacrylate polyfunctional vinyl monomers such as dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate;
Trimethacrylate polyfunctional vinyl monomers such as trimethylolpropane trimethacrylate and trimethylolethane trimethacrylate;
Styrene polyfunctional vinyl monomers such as divinylbenzene and trivinylbenzene;
Examples include methylene bisacrylamide, isoprene, butadiene, and vinyl crotonate.

  Since the modified resin particles may be easily produced while adjusting the molecular weight of the polymer obtained, either the (meth) acrylate polyfunctional vinyl monomer or the styrene polyfunctional vinyl monomer is used as the polyfunctional vinyl monomer. One is preferable, and any one of ethylene glycol dimethacrylate and divinylbenzene is more preferable.

  In the present invention, in order to obtain irregularly shaped resin particles, the polyfunctional vinyl monomer is used in an amount of 1 to 40 parts by weight, preferably 1.5 to 35 parts by weight, more preferably 100 parts by weight of the monofunctional vinyl monomer. 2 to 30 parts by weight are used. If the amount of the polyfunctional vinyl monomer is less than 1 part by weight with respect to 100 parts by weight of the monofunctional vinyl monomer, odd-shaped resin particles may not be obtained. May not be obtained.

  In addition, as a preferable combination of a monofunctional vinyl monomer and a polyfunctional vinyl monomer, a combination of any one of methyl methacrylate, butyl methacrylate, butyl acrylate, and styrene and any one of ethylene glycol dimethacrylate and divinylbenzene is given. It is done.

  In the present invention, a methacryl-modified silicone oil vinyl monomer is used to obtain irregular shaped resin particles. The methacryl-modified silicone oil-based vinyl monomer means a vinyl monomer in which one or more methacryl groups are bonded to a terminal portion or a side chain portion of a polysiloxane skeleton in a general-purpose silicone oil such as dimethyl silicone oil or methylphenyl silicone oil. . In addition, one or two or more other silicone oil-based vinyl monomers can be used as long as they do not affect the physical properties, production process, and the like of the deformed resin particles obtained.

  As other silicone oil-based vinyl monomers, specifically, alcohol-modified silicone oil-based vinyl monomers, amino-modified silicone oil-based vinyl monomers, mercapto-modified silicone oil-based vinyl monomers, methyl groups and reactive functional groups such as phenyl groups, Examples thereof include silicone oil-based vinyl monomers having one or more vinyl groups, such as different functional group-modified silicone oil-based vinyl monomers having an ether group or the like bonded thereto.

In the present invention, since irregularly shaped resin particles may be easily produced, the following general formula (I):
(In the formula, R is an alkylene group, R ′ is an alkyl group, and n is 5 to 350).
The methacryl-modified silicone oil vinyl monomer is more preferable.

  R is a vinyl group, a carbonyl group, an aromatic group, an ester group, an ether group, an aldehyde group, an amino group, a nitrile group, a nitro group, etc. These functional groups may be included. In addition, although depending on the amount of raw material used and the polymerization conditions, irregularly shaped resin particles can be obtained, so that R is preferably an alkylene group having 1 to 10 carbon atoms, and an alkylene group having 1 to 6 carbon atoms. More preferred. When the carbon number of R is greater than 10, irregular shaped resin particles may not be obtained. R may be linear or branched. Furthermore, R may not be included in the general formula (I) as long as irregular shaped resin particles can be obtained.

Similarly, R ′ is also vinyl group, carbonyl group, aromatic group, ester group, ether group, aldehyde group, amino group, nitrile group, as long as it does not affect the physical properties, production process, etc. And may contain a functional group such as a nitro group. In addition, although depending on the amount of raw material used and the polymerization conditions, irregularly shaped resin particles can be obtained, so that R ′ is preferably an alkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Is more preferable. When the carbon number of R ′ is greater than 10, irregular shaped resin particles may not be obtained. R ′ may be linear or branched.
On the other hand, when the value of n is smaller than 5 or larger than 350, irregular shaped resin particles may not be obtained.

  In the present invention, in order to obtain irregular shaped resin particles, the methacryl-modified silicone oil-based vinyl monomer is 1 to 100 parts by weight, preferably 3 to 90 parts by weight, based on 100 parts by weight of the monofunctional vinyl monomer. Preferably 5 to 80 parts by weight are used. When the amount of the methacryl-modified silicone oil vinyl monomer is less than 1 part by weight relative to 100 parts by weight of the monofunctional vinyl monomer, the deformed resin particles may not be obtained. Particles may not be obtained.

  In the present invention, odd-shaped resin particles are produced by polymerizing a monofunctional vinyl monomer, a polyfunctional vinyl monomer, and a methacryl-modified silicone oil-based vinyl monomer with a polymerizable initiator. Moreover, a well-known polymeric initiator can be used suitably as a polymeric initiator.

Specific examples of the polymerizable initiator include benzoyl peroxide, lauroyl peroxide, t-butyl peroxy octoate, t-hexyl peroxy octoate, t-butyl peroxy benzoate, t-amyl peroxy benzoate, t -Butyl peroxybivalate, t-butyl peroxyisopropyl carbonate, t-hexyl peroxyisopropyl carbonate, t-butyl peroxy-3,3,5-trimethylcyclohexanoate, di-t-butyl peroxyhexa Organic peroxides such as hydroterephthalate, 2,2-di-t-butylperoxybutane, di-t-hexyl peroxide, dicumyl peroxide;
Examples include azo compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile. In addition, as long as it does not have a bad influence on a polymerization system and a product, 1 type (s) or 2 or more types of polymeric initiators can be used.

In addition, as long as the deformed resin particles can be obtained, the vinyl monomer mixture may contain other vinyl monomers and additives. Specifically, the additives include a chain transfer agent, a light stabilizer, and an ultraviolet absorber. Agents, pigments, dyes, antifoaming agents, thickeners, heat stabilizers, leveling agents, lubricants, antistatic agents and the like.
On the other hand, aqueous media include ascorbic acid, sodium bisulfite, sodium thiosulfate, potassium permanganate, potassium dichromate, and other aqueous polymerization inhibitors, salt, salting-out agents such as ammonium sulfate, sodium hexametaphosphate, magnesium pyrophosphate, etc. Additives such as an aggregation inhibitor, a pH adjuster such as an inorganic acid, an organic acid, a basic compound, an antifoaming agent such as a silicon-based antifoaming agent, and a mineral oil-based antifoaming agent may be appropriately included.

In the present invention, irregular shaped resin particles can be obtained by performing polymerization in an aqueous medium in the absence of a hydrophobic liquid. Therefore, in order to remove these hydrophobic resin particles, it has been conventionally incorporated in the manufacturing process to remove these hydrophobic resin particles. Hydrophobic from the irregular resin particles in a solvent such as a lower alcohol that can dissolve only the hydrophobic liquid. No complicated cleaning process for removing the ionic liquid is required. Further, there is no need for large-scale washing equipment, drying equipment, etc. for performing the above-mentioned steps.
In the present invention, the hydrophobic liquid means a liquid that hardly exhibits solubility in an aqueous medium, and specifically, liquid paraffin, normal heptane, normal, which were conventionally required for producing irregular shaped resin particles. It means hydrocarbons such as hexane, esters, ethers, silicone oil, animal oil, vegetable oil and the like.
Further, in the present invention, the absence means that it does not exist to the extent that it does not affect the physical properties such as the shape, oil absorption, light diffusibility, production method, etc. of the deformed resin particles obtained. Therefore, a very small amount of hydrophobic liquid that does not affect the physical properties and the manufacturing method may be included in the manufacturing method of the present invention.

  Therefore, the production method of the present invention is very preferable in terms of production cost and the like. Furthermore, the production method of the present invention is extremely preferable in terms of the quality and physical properties of the irregular shaped resin particles.

For the polymerization of the irregular shaped resin particles, a known polymerization method as a polymerization method in an aqueous medium, that is, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, a seed polymerization method, or the like can be appropriately used. In the present invention, it is preferable to use a suspension polymerization method as a polymerization method because it may be possible to easily and safely produce irregular shaped resin particles while suppressing excessive heat generation and pressure increase during polymerization.
The aqueous medium is preferably 100 to 100 parts by weight of the monofunctional vinyl monomer.
2000 parts by weight, more preferably 150 to 1000 parts by weight are used. When the amount is more than 2000 parts by weight, there may be a problem in terms of production cost. On the other hand, when the amount is less than 100 parts by weight, excessive heat generation, pressure increase, etc. may occur during polymerization.

  As a method for dispersing the vinyl monomer mixture in the aqueous medium at the time of suspension polymerization, for example, a method in which the vinyl monomer mixture is directly added to the aqueous phase and the mixture is dispersed with a propeller blade of a reactor, etc. Examples thereof include a method of dispersing with a homomixer having, a method of dispersing with an ultrasonic disperser, and the like.

  Any one of a surfactant such as a cationic surfactant, a nonionic surfactant, an anionic surfactant, and a zwitterionic surfactant can be used as a dispersant used in suspension polymerization. Furthermore, polyvinyl alcohol, polyvinyl alcohol dispersants such as polyvinyl alcohol partial saponified products, cellulose dispersants such as methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, carboxymethyl cellulose, polyvinyl pyrrolidone, adipic acid-diethanolamine condensate, etc. Polymeric dispersants, inorganic dispersants such as colloidal silica, alumina sol, zirconia sol, and titanium sol can also be used as appropriate. Moreover, 1 type, or 2 or more types of dispersing agents can be used unless the physical property of the obtained irregular shaped resin particle, a manufacturing process, etc. are affected.

  Here, if the amount of the dispersant used is too small, the polymerization stability may be significantly lowered. On the other hand, when the amount is too large, polymerization in the aqueous phase is likely to occur, a large amount of fine particles are generated, and the yield of the desired deformed resin particles may be reduced. Therefore, the amount used is preferably 0.005 to 15 parts by weight and more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

  Next, polymerization is carried out by heating the suspension in which the vinyl monomer mixture is dispersed. During the polymerization, the suspension is preferably agitated, and the agitation is preferably performed so gently as to prevent floating of droplets and sedimentation of the deformed resin particles after polymerization.

  In the present invention, the polymerization temperature is preferably about 30 to 120 ° C., more preferably about 40 to 110 ° C. from the viewpoint of safety during production. The polymerization temperature is preferably maintained for about 0.1 to 20 hours. Furthermore, it is preferable to perform the polymerization in an inert gas atmosphere such as nitrogen or argon.

  Isolation of the deformed resin particles from the aqueous medium can be performed using a known isolation method. Specifically, the wet cake after the liquid removal step is left to dry in a batch-type hot air dryer or oven, the reaction slurry obtained is spray-dried with a spray dryer, etc. It can be carried out by a method of adhering to a heated rotating drum and drying, an air flow drying method, a freeze drying method, a reduced pressure drying method or the like. Moreover, since the irregular shaped resin particles after drying may contain agglomerates, it is preferable to break the agglomerates with a pulverizer, a crusher, or the like. Furthermore, it is preferable to remove coarse resin particles, fine resin particles, and the like that may adversely affect the physical properties of the irregular shaped resin particles by using the obtained irregular shaped resin particles with an air classifier, a vibration sieve, or the like.

  According to the production method of the present invention, irregular shaped resin particles can be easily produced. Here, the irregular shaped resin particles mean substantially non-spherical shaped resin particles. In the present invention, in particular, deformed resin particles having two or more recesses on the surface of the deformed resin particles (also referred to as uneven deformed resin particles in the present invention) or bowl-shaped deformed resin particles having one recess in the center ( In the present invention, it is also possible to obtain a bowl-shaped odd-shaped resin particle), which is prepared by adjusting the amount of the monofunctional vinyl monomer, polyfunctional vinyl monomer, and methacryl-modified silicone oil vinyl monomer. Can do. Moreover, as long as the irregular-shaped irregular shaped resin particles or the bowl-shaped irregular shaped resin particles of the present invention have desired oil absorption and light diffusibility, respectively, any one of irregular shaped resin particles and spherical resin particles of other shapes is used. May contain a small amount. Furthermore, since higher oil absorption may be expected, it is preferable that the deformed resin particles of the present invention have one or more hollow portions therein.

  Here, when 20 to 100 parts by weight of the methacryl-modified silicone oil-based vinyl monomer is used with respect to 100 parts by weight of the monofunctional vinyl monomer, it is easy to obtain irregular shaped irregularly shaped resin particles. On the other hand, when 1 part by weight to less than 20 parts by weight is used, the bowl-shaped deformed resin particles are easily obtained.

  In the present invention, the irregular-shaped irregularly shaped resin particles mean irregularly shaped resin particles having two or more concave portions on the irregularly shaped resin particle surface as shown in FIG.

  In the present invention, the bowl-shaped irregular resin particle means a bowl-shaped irregular resin particle having a concave portion at the center of the irregular-shaped resin particle shown in FIG. 2 and having a shape close to a hemisphere or a semi-elliptical sphere. Further, by the production method of the present invention, as shown in the schematic diagram of FIG. 4, the front surface is convex and the back surface (bottom) is concave, preferably the bottom diameter (D) is 0.8 to 170 μm. The ratio (D / H) of the diameter (D) to the thickness (H) from the bottom to the tip of the convex surface is 1.4 to 4, and the inner diameter (d) corresponding to the convex surface is 0.1. A bowl-shaped deformed resin particle having a size of 3 μm or more can be obtained. The maximum value of the inner diameter (d) is less than the bottom diameter (D).

  Here, when the diameter D is out of the range of 0.8 to 170 μm, the ratio D / H is out of the range of 1.4 to 4 or the inner diameter d is out of the range of 0.3 μm or more, The bowl-shaped irregularly shaped resin particles may not have sufficient oil absorption and light diffusibility. In addition, about the calculation method of the diameter D, ratio D / H, and the internal diameter d, it explains in full detail in an Example.

  The deformed resin particles obtained in the present invention have a large specific surface area as compared with spherical resin particles and the like, and therefore preferably have an oil absorption of 80 ml / 100 g or more, more preferably 90 ml / 100 g or more, and an excellent oil absorption. Deformed resin particles can be obtained. If the oil absorption is less than 80 ml / 100 g, sufficient oil absorption may not be obtained.

  Moreover, the irregular shaped resin particle whose average particle diameter becomes like this. Preferably it is 0.6-150 micrometers, More preferably, it is 1-50 micrometers by the manufacturing method of this invention. When the average particle diameter is smaller than 0.6 μm, the deformed resin particles obtained are extremely small, and the deformed resin particles may not be obtained. On the other hand, when the average particle diameter is larger than 150 μm, the obtained irregular shaped resin particles are extremely large, and a sufficient specific surface area may not be obtained.

  By using the irregular shaped resin particles of the present invention, a light diffusing material having excellent light diffusibility can be obtained. Examples of the light diffusing material include those in which a light diffusion layer in which irregular shaped resin particles are dispersed on the surface of the base sheet is formed on the surface of the base sheet. As the base material of the base material sheet, for example, polyethylene terephthalate, polycarbonate, polyimide, polyvinyl chloride, polyester, styrene-acrylonitrile copolymer, cyclopolyolefin polymer, acrylic resin, polyamide and other resin base materials, transparent glass sheet It can be used by appropriately selecting from inorganic base materials such as. The thickness is not particularly limited, but is preferably about several μm to 500 μm, more preferably about 10 to 200 μm in consideration of ease of processing, handling properties, and applications.

  In the present invention, the irregular shaped resin particles are used by being dispersed in a binder such as an acrylic resin. The proportion of the irregularly shaped resin particles with respect to the binder is not particularly limited, but considering light diffusion performance, it is preferably 15 to 500 parts by weight, more preferably 20 to 200 parts by weight with respect to 100 parts by weight of the binder.

  The method for forming the light diffusion layer of the light diffusing material is not particularly limited, and any known method can be used. For example, there is a method in which irregular shaped resin particles are added to a solution in which a binder is dissolved or dispersed to form a coating material for forming a light diffusion layer, and this coating material is applied on a substrate.

  Since the irregular shaped resin particles obtained in the present invention have sufficient oil absorption and light diffusibility, paint additives, cosmetic additives, toner additives, pressure-sensitive adhesives, light diffusing agents, liquid crystal spacers, binders, rheology modifiers, increasing amounts It can be widely used in various fields as an agent, a coating film performance improving agent, and the like. In particular, these irregularly shaped resin particles can be used as a light diffusing material, a cosmetic material, an organic pigment for paint, an organic pigment for paper coating, a carrier for diagnostic agents, and the like.

The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. Various manufacturing conditions and measurement methods will be described below.
<Oil absorption of irregular shaped resin particles>
The oil absorption amount of the irregular shaped resin particles is measured by the method of JIS K 5101. Details are as follows.
-Apparatus and instrument measuring plate A smooth glass plate larger than 300 x 400 x 5 mm.
Spatula A handle with a steel or stainless steel blade.
Weighing instrument: Can measure up to 10mg order.
Buret JIS R 3505, up to 10ml.
-Material linseed oil (as defined in JIS K 5421; this time using special grade linseed oil (manufactured by Wako Pure Chemical Industries))

-Measuring method (1) Before performing the following operations, the approximate value of the oil absorption is confirmed in advance by a preliminary test.
(2) Take 1 g of deformed resin particles at the center of the measuring plate and gradually drop linseed oil from the burette 4 or 5 drops at a time into the center of the deformed resin particles. The
(3) Repeat dripping and kneading. When the whole becomes a hard putty-like lump, knead each drop, and when the last one drop is ready to be spirally wound with a spatula, end point And However, if it cannot be spirally wound, the end point is the point immediately before it softens suddenly with one drop of linseed oil.
(4) Adjust the operations (1) and (2) so that the operation time to the end point is 7 to 15 minutes.
(5) Read the amount of linseed oil dropped on the burette when the end point is reached.

・ Calculation method Oil absorption is calculated by the following formula.
O = (V / m) × 100
O: Oil absorption (ml / 100g)
m: mass of irregular shaped resin particles (g)
V: Volume of dropped linseed oil (ml)
In this invention, when the value of oil absorption amount is 80 ml / 100g or more, it determines with a pass ((circle)).

<Average particle diameter of irregularly shaped resin particles>
The average particle diameter of the irregularly shaped resin particles of the present invention is measured by an electric resistance method, and specifically, measured as follows.
First, an aperture tube in which electrodes are arranged on both sides of an aperture (pore) is immersed in a suspension in which irregular shaped resin particles to be measured are suspended in an electrolytic solution. Next, an electric current is passed between the electrodes of the aperture tube via the suspension, and the electric resistance between the electrodes is measured. When the irregular shaped resin particles in the suspension are sucked and pass through the aperture, the electrolytic solution corresponding to the particle volume is replaced, and the electric resistance between the electrodes changes. Since the amount of change in electrical resistance is proportional to the size of the particles, the volume of particles can be calculated by converting the amount of change in electrical resistance into a voltage pulse, and amplifying and detecting the volume. The diameter of the true sphere corresponding to the volume is defined as the particle diameter of the deformed resin particles.

  Furthermore, the average particle diameter of the irregular shaped resin particles is calculated by taking the average of the particle diameters of the irregular shaped resin particles measured as described above. That is, the average particle diameter of the irregular shaped resin particles of the present invention means the volume average particle diameter. The average particle size of the irregular shaped resin particles can be measured using, for example, a measuring apparatus commercially available from Beckman Coulter, Inc. as a product name “Coulter Multisizer II”.

<Diameter D, ratio D / H and inner diameter d of bowl-shaped deformed resin particles>
The diameter D of the bottom of the bowl-shaped deformed resin particles, the thickness H from the bottom to the tip of the convex surface, and the inner diameter d corresponding to the convex surface are measured as follows (see FIG. 4).
Using a scanning electron microscope JSM-6360LV (manufactured by JEOL Ltd.), observe any 40 irregular shaped resin particles at 5,000 to 10,000 times, measure each part, and calculate the average value of the diameter D , Thickness H and inner diameter d.
1) The diameter of the particle plane shape is measured, and the longest diameter is defined as the bottom diameter D.
2) The surface having the diameter D as the center is the bottom, and the longest diameter of the normal line from the surface is the thickness H.
3) The distance between the two vertices on the diameter D is the inner diameter d.

<Light diffusibility of light diffusing material>
The optical properties such as light diffusibility of the light diffusing material containing irregular shaped resin particles are evaluated based on the total light transmittance and the haze value. The total light transmittance is measured according to JIS K 7361. Specifically, NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd. is used. The haze is measured according to JIS K 7136, and specifically, NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd. is used.
The total light transmittance and haze value are preferably 91% or more and 93% or more, respectively.

Example 1
An aqueous medium in which 15 parts by weight of magnesium pyrophosphate was dispersed in 1000 parts by weight of deionized water was added to a 2 L polymerization vessel equipped with a stirrer and a thermometer, and 0.02 part by weight of sodium lauryl sulfate was further added. 260 parts by weight of methyl methacrylate (monofunctional vinyl monomer) prepared in advance, 40 parts by weight of ethylene glycol dimethacrylate (polyfunctional vinyl monomer), 40 parts by weight of methacrylic modified silicone oil (vinyl monomer based on methacrylic modified silicone oil) , Manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-174DX) and 0.9 part by weight of azobisisobutyronitrile (polymerization initiator) were added to the polymerization vessel. Then, the mixed solution was mixed with T.W. A suspension having a droplet diameter of about 10 μm was prepared by dispersing in an aqueous medium with a K homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). While stirring with a stirrer, the suspension was heated to 65 ° C. and polymerized for 6 hours, then heated to 100 ° C., heated for 2 hours, and cooled to room temperature (about 20 ° C.). The obtained suspension was filtered, washed and dried to obtain irregular shaped resin particles.
The average particle diameter of the obtained irregular shaped resin particles was 10 μm.
The irregular shaped resin particles were bowl shaped irregular shaped resin particles having a diameter D of 13 μm, a ratio D / H of 1.7, and an inner diameter d of 7.5 μm.

  140 parts by weight of an acrylic binder (product name: LR-102, manufactured by Mitsubishi Rayon Co., Ltd.) was mixed with 100 parts by weight of the obtained irregular shaped resin particles. Thereto was added 260 parts by weight of a mixed solution of toluene and methyl ethyl ketone at a ratio of 1: 1 as a solvent, and this was stirred for 3 minutes by a centrifugal stirrer. This solution was allowed to stand for 3 hours, and then again stirred for 3 minutes with a centrifugal stirrer. After the irregular shaped resin particles were uniformly dispersed in the solution, this solution was coated on a 125 μm thick PET film (manufactured by Mitsubishi Chemical Polyester Film) using a 100 μm coater. The obtained film was dried for 1 hour in a drier kept at 70 ° C. to obtain a light diffusing material (light diffusing sheet).

  Table 1 shows the measurement results of the oil absorption amount of the irregularly shaped resin particles and the total light transmittance and haze of the light diffusing material.

Example 2 (Reference Example)
165 parts by weight of methyl methacrylate, 5 parts by weight of ethylene glycol dimethacrylate and 150 parts by weight of methacryl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-2)
The same procedure as in Example 1 was carried out except that 426).

The average particle diameter of the obtained irregular shaped resin particles was 11 μm.
The irregular shaped resin particles were irregular shaped irregular shaped resin particles.
Table 1 shows the measurement results of the oil absorption amount of the irregularly shaped resin particles and the total light transmittance and haze of the light diffusing material.

Example 3 (Reference Example)
Methyl methacrylate 250 parts by weight, ethylene glycol dimethacrylate 50 parts by weight and methacryl-modified silicone oil 65 parts by weight (manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-2
The same procedure as in Example 1 was carried out except that 426).

The average particle diameter of the obtained irregular shaped resin particles was 11 μm.
The irregular shaped resin particles were irregular shaped irregular shaped resin particles.
Table 1 shows the measurement results of the oil absorption amount of the irregularly shaped resin particles and the total light transmittance and haze of the light diffusing material.

Example 4
The same procedure as in Example 1 was carried out except that 260 parts by weight of methyl methacrylate, 40 parts by weight of ethylene glycol dimethacrylate, and 9 parts by weight of methacryl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-2426) were used.

The average particle diameter of the obtained irregular shaped resin particles was 9 μm.
The irregular shaped resin particles were bowl shaped irregular shaped resin particles having a diameter D of 11 μm, a ratio D / H of 1.6, and an inner diameter d of 7.2 μm.
Table 1 shows the measurement results of the oil absorption amount of the irregularly shaped resin particles and the total light transmittance and haze of the light diffusing material.

Example 5
Methyl methacrylate 260 parts by weight, styrene 10 parts by weight (monofunctional vinyl monomer), ethylene glycol dimethacrylate 30 parts by weight and methacrylic modified silicone oil 50 parts by weight (manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-2426) Except for this, the same procedure as in Example 1 was performed.

The average particle diameter of the obtained irregular shaped resin particles was 11 μm.
The irregular shaped resin particles were bowl shaped irregular shaped resin particles having a diameter D of 14 μm, a ratio D / H of 1.9, and an inner diameter d of 7.8 μm.
Table 1 shows the measurement results of the oil absorption amount of the irregularly shaped resin particles and the total light transmittance and haze of the light diffusing material.

Example 6
150 parts by weight of butyl methacrylate (monofunctional vinyl monomer), 60 parts by weight of butyl acrylate (monofunctional vinyl monomer), 65 parts by weight of ethylene glycol dimethacrylate and 35 parts by weight of methacryl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name) The same procedure as in Example 1 was carried out except that X-22-2426).

The average particle diameter of the obtained irregular shaped resin particles was 10 μm.
The irregular shaped resin particles were bowl shaped irregular shaped resin particles having a diameter D of 13 μm, a ratio D / H of 1.8, and an inner diameter d of 8.1 μm.
Table 1 shows the measurement results of the oil absorption amount of the irregularly shaped resin particles and the total light transmittance and haze of the light diffusing material.

Example 7
Same as Example 1 except that 260 parts by weight of methyl methacrylate, 40 parts by weight of divinylbenzene (polyfunctional vinyl monomer) and 50 parts by weight of methacryl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-2426) were used. Implemented.

The average particle diameter of the obtained irregular shaped resin particles was 11 μm.
The irregular shaped resin particles were bowl shaped irregular shaped resin particles having a diameter D of 15 μm, a ratio D / H of 1.7, and an inner diameter d of 7.7 μm.
Table 1 shows the measurement results of the oil absorption amount of the irregularly shaped resin particles and the total light transmittance and haze of the light diffusing material.

Comparative Example 1
The same procedure as in Example 1 was performed except that 120 parts by weight of methyl methacrylate, 20 parts by weight of ethylene glycol dimethacrylate, and 150 parts by weight of methacryl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-2426) were used.

The average particle diameter of the obtained resin particles was 11 μm.
The resin particles were spherical resin particles.
Table 1 shows the measurement results of the oil absorption of the resin particles, the total light transmittance of the light diffusing material, and the haze.

Comparative Example 2
The same procedure as in Example 1 was carried out except that 300 parts by weight of methyl methacrylate and 20 parts by weight of methacryl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-2426) were used.

The average particle diameter of the obtained resin particles was 10 μm.
The resin particles were spherical resin particles.
Table 1 shows the measurement results of the oil absorption of the resin particles, the total light transmittance of the light diffusing material, and the haze.

Comparative Example 3
Executed in the same manner as in Example 1 except that 270 parts by weight of methyl methacrylate, 30 parts by weight of ethylene glycol dimethacrylate, and 0.3 parts by weight of methacryl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name X-22-174DX) were used. did.

The average particle diameter of the obtained resin particles was 10 μm.
The resin particles were spherical resin particles.
Table 1 shows the measurement results of the oil absorption of the resin particles, the total light transmittance of the light diffusing material, and the haze.

  Table 1 shows the raw material types of Examples and Comparative Examples.

Table 1 shows that the resin particles obtained in Examples 1 to 7 are odd-shaped resin particles having excellent oil absorption.
Similarly, it is shown that the light diffusing material obtained by using the deformed resin particles obtained in Examples 1 to 7 has excellent light diffusibility such as total light transmittance and haze.
Moreover, it has shown that the irregular shaped resin particle can be manufactured by the manufacturing method of Examples 1-7 in absence of hydrophobic liquid.

  Therefore, the manufacturing method according to the present invention makes it easy to form a deformed resin particle having excellent oil absorbency and light diffusibility without requiring a hydrophobic liquid and a removal step thereof, which were conventionally required when manufacturing the deformed resin particle. Shows that you can get to.

  Therefore, since the deformed resin particles obtained in the present invention have sufficient oil absorption and light diffusibility, paint additives, adhesives, cosmetic additives, toner additives, light diffusing agents, liquid crystal spacers, binders, rheology modifiers. It can be widely used in various fields as a bulking agent, a coating film performance improving agent, and the like.

D Diameter of bottom H Thickness from bottom to tip of convex surface d Inner diameter corresponding to convex surface

Claims (5)

Methyl methacrylate, butyl methacrylate, at least one selected from the group consisting of at least one monofunctional vinyl monomer 100 parts by weight, d Ji glycol dimethacrylate and divinylbenzene selected from the group consisting of butyl acrylate and styrene 1 to 40 parts by weight of a polyfunctional vinyl monomer and 1 to less than 20 parts by weight of a methacryl-modified silicone oil-based vinyl monomer are polymerized in an aqueous medium in the absence of a hydrophobic liquid. A manufacturing method comprising:
The methacryl-modified silicone oil-based vinyl monomer has the general formula (I):
(In the formula, R is an alkylene group, R ′ is an alkyl group, and n is 5 to 350).
A methacryl-modified silicone oil vinyl monomer
The deformed resin particle is a bowl-shaped deformed resin particle having one recess at the center of the deformed resin particle, the diameter (D) of the bottom of the deformed resin particle is 0.8 to 170 μm, and the diameter ( The ratio (D / H) between D) and the thickness (H) from the bottom to the tip of the convex surface of the deformed resin particle is 1.4 to 4, and the inner diameter corresponding to the convex surface of the deformed resin particle (D) The manufacturing method of the irregular-shaped resin particle which is 0.3 micrometer or more.   The method for producing deformed resin particles according to claim 1, wherein the polymerization is suspension polymerization.   Shaped resin particles obtained by the production method according to claim 1 or 2.   The deformed resin particles according to claim 3, wherein the deformed resin particles have an oil absorption of 80 ml / 100 g or more.   A light diffusing material comprising the irregular shaped resin particles according to claim 3.