JP2008174706A - Composite particle including olefinic thermoplastic resin comprising amorphous macromolecule as core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide fine macromolecule particles which include amorphous olefinic macromolecules having an excellent abilities, such as a high light transmittance or a low water absorption, as a main component, possess enhanced dispersibility into a solvent with polarity or increased adhesiveness to a binder, and has a function of light scattering. <P>SOLUTION: The composite particles are generally spherical particles comprising an olefinic thermoplastic resin (A) comprising the amorphous macromolecules with a crystallinity of 5 wt.% or less by weight and a thermoplastic resin (B) having polarity, have a number average particle diameter of 1 μm to 5,000 μm, and possess a core-shell structure containing an olefinic thermoplastic resin (A) as the core and a thermoplastic resin (B) having the polarity as the shell. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is mainly composed of an amorphous olefin polymer having excellent performance such as high light transmittance or low water absorption, taking advantage of its characteristics and enhancing dispersibility in polar solvents, or The present invention relates to polymer fine particles having improved adhesion to a binder and having a function of light scattering.

Originally, as a method of obtaining polymer fine particles having a core-shell structure, that is, composite resin particles, the seed emulsion polymerization method in which a polymer monomer is polymerized after synthesizing core polymer fine particles is the most common. is there. For example, JP-A-7-70255 (Patent Document 1) discloses a method for producing a core-shell polymer having an alkyl acrylate rubber core and a methyl methacrylate glass shell.
However, as long as this seed emulsion polymerization method is used, the core polymer is also limited to a polymer that can be polymerized in an emulsified state or a suspended state. In addition, because of the production method of polymerizing the core polymer, it is difficult to stably produce polymer fine particles having a core particle diameter exceeding 1 μm with a narrow particle size distribution. For this reason, polymers applicable to the seed emulsion polymerization method are limited to resins using monomers capable of radical polymerization in emulsion polymerization or suspension polymerization. Therefore, the kind of polymer used for the shell is also limited. For this reason, the seed emulsion polymerization method cannot be applied to a polymer that undergoes radical polymerization by a high pressure method, such as a condensation reaction, a high pressure method polyolefin, or a cyclic polyolefin.
For the reasons described above, it has been impossible to use an olefin polymer composed of an amorphous polymer, for example, a cyclic polyolefin as a core material.

  On the other hand, as a method for producing fine polymer particles having a core-shell structure other than the polymerization method, Japanese Patent Application Laid-Open No. 2005-162797 (Patent Document 2) includes an organic solid component (resin component, etc.) (A), This organic solid component (A) is a dispersion composed of a plurality of organic solid substances (resins, etc.) having different affinity for the water-soluble auxiliary component (B) containing at least the oligosaccharide (B1). Thus, a method for producing organic solid particles, that is, polymer fine particles or resin fine particles having a core-shell structure by removing the auxiliary component (B) from the dispersion is disclosed. Hereinafter, this method may be referred to as a forced emulsification method. Among them, for example, the use of an olefin polymer as an organic solid component is disclosed, but there is no specific description of a core-shell composite structure particle having an olefin polymer as a core material. The core-shell structured particles are not described.

Olefin polymers consisting of amorphous polymers, especially cyclic polyolefin polymers, have both high transparency and a high refractive index. It is expected that fine particles having a high refractive index can be obtained. On the other hand, the cyclic polyolefin polymer has high hydrophobicity, and when using a water-soluble auxiliary component, it is difficult to simply form fine particles.
Further, there is no disclosure or suggestion of spherical resin fine particles having both particularly high light transmittance and light scattering properties. In particular, when a cyclic olefin resin is used as the amorphous olefin resin of the core, the high glass transition temperature inherent in the cyclic olefin resin, the high viscosity at the time of melting, and the use process after the production of the polymer fine particles There has been no disclosure or suggestion of means to improve the low affinity of organic solvents for organic solvents.
JP-A-7-70255 (Claim 1) JP 2005-162797 A (Claims 1, 24)

  The problems to be solved include high light transmittance, high affinity with organic solvents and various binders in the process of using fine particles, dispersibility in organic solvents and suspensions in which fine particles are dispersed, This is the point that fine particles having high stability did not exist. Furthermore, there are no spherical fine particles having good affinity with various binders (curing agents) used in the step of using the fine particles.

  A further problem to be solved by the present invention is that spherical composite particles having high light transmittance but having light scattering properties did not exist.

  The present invention is a substantially spherical composite particle comprising an olefinic thermoplastic resin (A) comprising an amorphous polymer having a crystallinity of 5% by weight or less, and a thermoplastic resin (B) having polarity, The number average particle diameter is 1 μm to 5,000 μm, and it is most preferable to use composite particles having a core-shell structure in which the olefinic thermoplastic resin (A) is the core and the polar thermoplastic resin (B) is the shell. Main features.

  That is, in the present invention, the olefinic thermoplastic resin (A) made of an amorphous polymer is the core of the composite particles, so that the light transmittance of the composite particles can be increased. And since the thermoplastic resin (B) which has polarity becomes a shell layer, affinity with the organic solvent which has polarity, and various binders can be made high. As a result, dispersibility in an organic solvent and stability in a suspension in which fine particles are dispersed can be improved. Moreover, the adhesive force with various binders (curing agents) in which fine particles are used can be improved.

Further, in the present invention, the refractive index of the olefinic thermoplastic resin (A) constituting the composite particles and the thermoplastic resin (B) having polarity may be different. That is, the ratio obtained by dividing the refractive index of the thermoplastic resin (B) having polarity by the refractive index of the olefinic thermoplastic resin (A) constituting the composite particles is 0.98 or less, or 1.02 or more. Some fine particles may be used. Thereby, it can be set as the microparticles | fine-particles with the high light transmittance of a composite particle, and a light-scattering property.
Further, in the present invention, fine particles in which the weight ratio of the olefinic thermoplastic resin (A) and the polar thermoplastic resin (B) is in the range of 50/50 to 99/1 may be used. When the ratio of the olefinic thermoplastic resin (A) is lower than 50% by weight, the light transmittance of the composite particles becomes low. On the other hand, if the ratio of the thermoplastic resin (B) having polarity is lower than 1% by weight, the thermoplastic resin (B) having polarity in the shell of the composite particles may not form a uniform layer.

Further, the present invention may be composite particles having a moisture absorption rate of 0.5% by weight or less as particles. That is, since the thermoplastic resin (B) having polarity constitutes a part of the composite particles as the shell layer, resin fine particles having a low moisture absorption rate as particles can be obtained.
In the present invention, composite particles having a light transmittance of 80% or more and a haze value of 60% or more by appropriately setting the kind of the thermoplastic resin (B) having the polarity of the shell layer may be used. .

The composite particles having the constitution of the present invention have advantages unique to the cyclic olefin resin such as low water absorption and high transparency. On the other hand, dispersibility and adhesiveness for polar solvents such as water and alcohols, polar adhesives such as epoxy adhesives, and polar resins are improved.
Furthermore, composite particles having high haze despite high light transmittance due to the difference in refractive index between the core olefinic thermoplastic resin (A) and the polar thermoplastic resin (B). Can do. By using such composite particles of the present invention, necessary light scattering properties such as a scattering plate of a liquid crystal display device can be imparted.

  The composite particles of the present invention can reduce water absorption. Specifically, it can be 0.5 wt% (5,000 ppm) or less.

  When the composite particles of the present invention are prepared by using a two-part epoxy adhesive (Konishi Co., Ltd., Bondquick 5) as a binder and measuring the cohesive failure strength, the particles composed of the core resin alone are used. Compared to the case where it is used, the cohesive fracture strength can be improved by 20% or more.

  The composite particles of the present invention include an olefin-based thermoplastic resin (A) substantially composed of an amorphous polymer whose crystallinity of the thermoplastic resin is 5% by weight or less, and a thermoplastic resin (B) having polarity. It consists of and.

  In the present invention, the terms “polymer”, “hydrophobic polymer”, “hydrophilic polymer”, “water-soluble polymer”, “plastic”, and “thermoplastic resin” are referred to as “New Edition Polymer Dictionary” (published by Asakura Shoten, Polymer Society) : According to the definition of November 25, 19988 (first edition). However, when the term "polymer" is used in the term polymer fine particles, it is synonymous with the term "plastic" in the above-mentioned "new edition polymer dictionary". This means a mixture of fillers, plasticizers, stabilizers, pigments and other additives. When the term “resin” is used as a constituent of fine particles, such as “resin fine particles” and “resin particles”, it is synonymous with “plastic” as defined in the above-mentioned “New Edition Polymer Dictionary”.

  If the term “resin” is used after the name of a specific polymer, the broad meaning of the JIS Industrial Dictionary (published and edited by the Japanese Standards Association, published on October 20, 1996, third edition) That is, it is the same meaning as “used to specify some polymers that are base materials for plastics”.

  The production method of the composite particles of the present invention is not particularly limited, but the amorphous olefin-based thermoplastic resin (A) and the polar thermoplastic resin (B) are the matrix component (C). A dispersion is formed by melt-mixing or kneading with a water-soluble emulsifying medium. This dispersion is eluted or dissolved with water, and a composite spherical resin particle composed of the amorphous olefin-based thermoplastic resin (A), which is a water-insoluble polymer, and a polar thermoplastic resin (B). (Hereinafter, this method is referred to as “forced emulsification method”) is preferable because the polymer used is thermoplastic.

Hereinafter, the amorphous olefin-based thermoplastic resin (A) used in the present invention will be described in detail.
(A) Olefin-based thermoplastic resin comprising amorphous polymer The olefin-based thermoplastic resin (A) comprising an amorphous polymer in the present invention is an olefin-based polymer and from an amorphous polymer. The following thermoplastic resin is used. An amorphous polymer is a polymer which is also called an amorphous polymer and does not show a clear crystal state, and is often found in an atactic polymer, a copolymer polymer and the like. The amorphous polymer referred to in the present invention is an amorphous polymer in a broad sense that does not exhibit clear crystallinity, and those containing a slight crystal structure are also included in the category of amorphous polymer. That is, the copolymer polymer or the like may include a crystalline portion locally or minutely, but such a polymer is regarded as an amorphous polymer in the present invention. Specifically, those having a crystallinity of 5% or less are also included in the amorphous polymer. Note that the crystallinity measurement method in this case refers to the crystallinity in the X-ray analysis intensity of the crystal part and the amorphous part.

  As the olefinic thermoplastic resin (A) comprising the amorphous polymer of the present invention, it is most preferable to use a cyclic olefin monomer polymer and a copolymer thereof. A cyclic polyolefin monomer polymer and a copolymer thereof are a general term for polymers composed of a polymerizable cyclic olefin having an ethylenic double bond in a ring as a monomer unit, and a cyclic olefin alone or a copolymer thereof [ Examples include ring-opening polymers of cyclic olefins alone, ring-opening polymers of two or more types of cyclic olefins (such as copolymers of monocyclic olefins and polycyclic olefins such as norbornenes, etc.). The olefin-based thermoplastic resin (A) comprising the amorphous polymer of the present invention may contain a cyclic olefin monomer polymer and a copolymer thereof as a part of the constituent components, and is copolymerizable with the cyclic olefin. In addition to copolymers with monomers, cyclic olefin monomer polymers and polymer blends or polymer alloys based on these copolymers (the above polymers, various rubber-like polymers, amide polymers and ester polymers, elastic elastomers) Etc.).

  Examples of such a polymer or copolymer include JP-A-60-168708, JP-A-612020816, JP-A-62-252406, JP-A-2-167318, It is disclosed in JP-A-4-35653. In the present invention, the cyclic olefin monomer polymer and its copolymer are referred to as a cyclic olefin monomer polymer. The olefinic thermoplastic resin composed of an amorphous polymer is a hydrophobic polymer as represented by the above cyclic polyolefin monomer polymer.

  Typical cyclic olefins include, for example, norbornenes, cyclopentadiene or dicyclopentadiene, 1,4,5,8-dimethano-1,2,3,4 obtained by condensation of norbornenes and cyclopentadiene. , 4a, 5,8,8a-octahydronaphthalenes, hexacyclo [6.6.1.1.1.1.0] heptadecene-4s, 6-ethylbicyclo [2 synthesized from ethylene and cyclopentadiene 2.1] hept-2-ene and the like. A cyclic olefin can be used individually or in combination of 2 or more types. The cyclic olefin may be a norbornene.

  The monomer to be copolymerized in the cyclic olefin monomer copolymer is not particularly limited as long as copolymerization is possible, but a chain olefin [alkene (for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene). 3-methyl-1-butene, 2-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene , C2-20 alkenes such as 1-eicosene), alkadienes (for example, 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl) 1,4-hexadiene, 1,7-nonconjugated C5-20 alkadiene such as octadiene), etc.], and others. These copolymerizable monomers can be used alone or in combination of two or more. Copolymerizable monomers are α-olefins (for example, C2-10α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, particularly C2-6α-olefins). Also good.

  Furthermore, as long as the object of the present invention is not impaired, a polymerizable nitrile compound (for example, (meth) acrylonitrile), a (meth) acrylic monomer (for example, (meth) acrylic) is used as a copolymerizable monomer. (Meth) acrylic acid esters such as methyl acid, ethyl (meth) acrylate, (meth) acrylic acid, etc.), unsaturated dicarboxylic acids or derivatives thereof (such as maleic anhydride), and the like may be used. These copolymerizable monomers may be used alone or in combination of two or more.

  A preferable cyclic polyolefin monomer polymer is a copolymer of an α-olefin and a cyclic olefin (for example, a copolymer of an α-C2-4 olefin such as an ethylene-cyclic olefin copolymer and a cyclic olefin). Such a copolymer combines the properties of an olefin polymer (such as an ethylene polymer) and a cyclic olefin polymer homopolymer, and the desired glass can be obtained by adjusting the copolymerization ratio of α-olefin. A polymer having a transition temperature and a high molecular weight can be obtained. From the viewpoint of heat resistance, a cyclic polyolefin monomer polymer obtained by condensing norbornenes and cyclopentadiene (or dicyclopentadiene), norbornenes and cyclopentadiene (or dicyclopentadiene), and a copolymerizable monomer ( For example, a cyclic polyolefin copolymer obtained by polymerizing α-olefins) is preferable. In the latter cyclic polyolefin copolymer, the amount of the copolymerizable monomer (for example, α-olefins) used is not particularly limited, but a small amount (for example, 1 to 25 mol%, preferably 2 to 20 mol%). Degree).

  A cyclic polyolefin monomer polymer (for example, a copolymer of an α-olefin and a cyclic olefin) has a high glass transition temperature and is prone to breakage. And it becomes difficult to granulate such a cyclic polyolefin monomer polymer by a conventional method. However, even if it is a high molecular weight cyclic polyolefin monomer polymer having a high glass transition temperature, high molecular weight cyclic polyolefin monomer polymer fine particles can be obtained by micronization using the method of the present invention.

As an index of the plasticizing temperature of the cyclic polyolefin monomer polymer (A), a glass transition temperature can be used, and the glass transition temperature of the cyclic polyolefin monomer polymer (A) depends on desired properties such as heat resistance. 70 to 200 ° C. (for example, 75 to 190 ° C.), preferably 80 to 175 ° C. (for example, 85 to 165 ° C.), and more preferably 90 to 150 ° C. (for example, 95 to 140 ° C.).
When the glass transition temperature is low, the plasticization temperature is low and the range of selection of the matrix component auxiliary agent (BC) is widened, but the heat resistance of the fine particles is reduced. In the present invention, a cyclic polyolefin monomer polymer (A) having a high glass transition temperature is obtained by using a water-soluble polysaccharide (C2B3) having at least one cyclic structure as a matrix component auxiliary agent (CB). In addition, spherical fine particles (fine spherical fine particles with a small average aspect ratio and fine particles with a small average particle diameter) can be obtained effectively, and the heat resistance of the spherical fine particles can be improved. Therefore, the glass transition temperature of the cyclic polyolefin monomer polymer (A) may be 100 to 180 ° C. (for example, 120 to 150 ° C.), preferably about 130 to 145 ° C.

  The molecular weight of the cyclic olefin monomer polymer resin is 2 × 10 4 to 30 × 10 4 (for example, 3 × 10 4 to 25 × 10 4), preferably 4 × 10 4 to 20 × 10 4 (for example, 5 ×). 104-18x104), more preferably about 7x104-15x104 (8x104-12x104). In addition, it is not preferable that the cyclic polyolefin monomer polymer having a weight average molecular weight of 2 × 104 or less is finely divided by the pulverization method, because the molecular weight further decreases, and the cyclic polyolefin monomer polymer exceeding 2 × 104 is physically pulverized. It is difficult. On the other hand, in the present invention, even a cyclic polyolefin monomer polymer having such a molecular weight can be formed into fine particles while preventing a decrease in molecular weight.

(B) Thermoplastic resin having polarity As thermoplastic resin (B) having polarity, polyester (for example, aromatic polyester and aliphatic polyester), polyamide, polyurethane, poly (thio) ether (for example, polyacetal, polyphenylene ether) , Polysulfide, polyetherketone, etc.), polycarbonate, polysulfone, polyimide, and other condensed polymers; poly (meth) acryl, polyvinyl (eg, halogen-containing polyvinyl, polyvinyl ester or derivatives thereof), and other polyvinyl polymerized polymers, cellulose Examples include resins derived from natural products such as derivatives.

  The heat distortion temperature (for example, Vicat softening point specified by JIS K 7206) of the thermoplastic resin can be selected from a range of 60 to 300 ° C, for example, 80 to 260 ° C, preferably 100 to 240 ° C (for example, 110 to 110 ° C). 240 ° C.), more preferably about 120 to 230 ° C. (for example, 130 to 220 ° C.).

  The average molecular weight of the thermoplastic resin having polarity is a weight average molecular weight in terms of polystyrene by gel permeation chromatography, and is, for example, 5,000 to 500,000, preferably 10,000 to 300,000, and more preferably 20,000. It may be about 000 to 150,000.

  These resins can be used alone or in combination of two or more. Hereinafter, typical thermoplastic resins will be exemplified, but these examples include those copolymers, graft modified products, block copolymers and the like. Hereinafter, the thermoplastic resin (B) having a suitable polarity of the present invention will be described in detail.

(1) Copolymers with (meth) acrylic acid and esters thereof (Meth) acrylic acid and copolymers with esters thereof include (meth) acrylic monomers ((meth) acrylic acid, ( (Meth) acrylic acid C1-18 alkyl ester, hydroxyalkyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylonitrile, etc.) or a copolymer such as poly (meth) acrylate methyl (Meth) acrylic acid ester, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate-acrylic acid ester- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer , (Meth) acrylic acid ester-styrene copolymers (MS resin and the like) and the like.

(2) Examples of the polyamide polymer polyamide-based resin include aliphatic polyamide-based resins, alicyclic polyamide-based resins, aromatic polyamide-based resins, and the like. Usually, aliphatic polyamide-based resins are used. These polyamide resins can be used alone or in combination of two or more.

  Aliphatic polyamide resins include aliphatic diamine components (C4-10 alkylenediamine such as tetramethylenediamine and hexamethylenediamine) and aliphatic dicarboxylic acid components (C4-20 alkylene such as adipic acid, sebacic acid and dodecanedioic acid). C4-20 lactams such as condensates with dicarboxylic acids (for example, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, polyamide 1212, etc.), lactams (ε-caprolactam, ω-laurolactam, etc.) Or a homo- or copolymer of an aminocarboxylic acid (such as C4-20 aminocarboxylic acid such as ω-aminoundecanoic acid) or a copolymer (for example, polyamide 6, polyamide 11, polyamide 12, polyamide 6/11, polyamide 6 / 12), these points Examples thereof include copolyamides (for example, polyamide 66/11, polyamide 66/12, etc.) in which lyamide components are copolymerized. The dicarboxylic acid component of the polyamide resin may contain a dimer acid unit. Furthermore, the polyamide-based resin may have biodegradability.

(3) Polyester polymer As the polyester polymer, for example, a homopolyester or copolyester obtained by polycondensation of a dicarboxylic acid component and a diol component; a homopolyester or copolyester obtained by polycondensation of oxycarboxylic acid; a lactone And homopolyester or copolyester obtained by ring-opening polymerization. These polyester polymers can be used alone or in combination of two or more.

(4) Polyurethane polymer Polyurethane polymer can be obtained by reaction of diisocyanates and polyols (for example, diols) and, if necessary, a chain extender. Diisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate and isophorone diisocyanate, phenylene diisocyanate, tolylene diisocyanate, Examples thereof include aromatic diisocyanates such as diphenylmethane-4,4′-diisocyanate and 1,5-naphthalene diisocyanate, and aromatic aliphatic diisocyanates such as xylylene diisocyanate.

(5) Poly (thio) ether polymer The poly (thio) ether polymer includes polyalkylene glycol, polyphenylene ether polymer, and polysulfide polymer (polythioether polymer). Examples of the polyalkylene glycol include homopolymers or copolymers (poly C2-4 alkylene glycol, etc.) of alkylene glycol such as polypropylene glycol, polytetramethylene ether glycol, and polyoxyethylene-polyoxypropylene block copolymer. These poly (thio) ether polymers can be used alone or in combination of two or more.

(6) Polycarbonate polymer Polycarbonate polymers include aromatic polycarbonates based on bisphenols (such as bisphenol A) and aliphatic polycarbonates such as diethylene glycol bisallyl carbonate. These polycarbonate polymers can be used alone or in combination of two or more.

(7) Polysulfone polymer Polysulfone polymers include polysulfone polymers and polyethersulfone polymers obtained by polycondensation of dihalogenodiphenylsulfone (dichlorodiphenylsulfone, etc.) and bisphenols (bisphenol A or metal salts thereof, etc.). And polyallylsulfone polymer (trade name: RADEL). These polysulfone polymers can be used alone or in combination of two or more.

(8) Vinyl polymers Vinyl polymers include vinyl monomers alone or copolymers, or copolymers with other copolymerizable monomers. As the vinyl monomer, in particular, a derivative of a vinyl ester polymer, for example, a vinyl alcohol polymer (for example, polyvinyl acetal such as polyvinyl formal, polyvinyl butyral; a saponified product of the vinyl acetate copolymer, for example, An ethylene-vinyl alcohol copolymer, etc.) can be preferably used. Among these vinyl alcohol polymers, a saponified vinyl acetate copolymer, particularly an ethylene-vinyl alcohol copolymer is preferable. In the saponified vinyl acetate copolymer, the degree of hydrophilicity may be adjusted by adjusting the proportion of hydrophobic comonomer units (for example, ethylene units in an ethylene-vinyl alcohol copolymer). When using a saponified vinyl acetate copolymer as a hydrophilic polymer, the proportion of the hydrophobic comonomer unit is adjusted to, for example, about 10 to 40% by weight from the viewpoint of affinity for the auxiliary component (B). May be.

(9) Cellulose derivative Examples of the cellulose derivative include cellulose esters (such as cellulose acetate and cellulose phthalate), cellulose carbamates (such as cellulose phenyl carbamate), and cellulose ethers (such as cyanoethyl cellulose). These cellulose derivatives can be used alone or in combination of two or more.
Examples of cellulose esters include cellulose acetates (cellulose acetate) such as cellulose diacetate and cellulose triacetate, organic acid esters (or acyl celluloses) such as cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate. ); Inorganic acid esters such as cellulose nitrate, cellulose sulfate and cellulose phosphate; and mixed acid esters such as cellulose nitrate acetate.

  Examples of the cellulose ether include alkyl cellulose (for example, C2-6 alkyl cellulose such as ethyl cellulose, isopropyl cellulose, and butyl cellulose), aralkyl cellulose (for example, benzyl cellulose), cyanoethyl cellulose, and the like.

  Although the ratio of the thermoplastic resin (A) and the thermoplastic resin (B) in the core-shell particles of the present invention is not particularly limited, the resin (A) has excellent functions such as low water absorption and high light transmittance. In order to express yesterday such as dispersibility, adhesion, and light scattering properties imparted by the resin (B) that forms the shell, the weight ratio of the resin (A) / resin (B) is preferably Is 50/50 to 99/1, more preferably 60/40 to 95/5, and most preferably 70/30 to 90/10.

(C) Matrix component The particles of the present invention can be produced, for example, by the forced emulsification method as described above. Particularly preferably, it can be obtained using the method described in JP-A-2005-162797. In this case, in a dispersion in which core-shell particles having an olefin-based thermoplastic resin (A) made of an amorphous polymer as a core and a polar thermoplastic resin (B) as a shell are dispersed in a removable matrix, The matrix component (C) constituting the matrix may be any component that can disperse the olefinic thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having polarity. That is, the matrix component (C) is usually a component that is not compatible (or incompatible) with the amorphous olefin-based thermoplastic resin (A) and the polar thermoplastic resin (B). If it is. The matrix (or matrix component) is usually solid (solid at room temperature). Such a solid matrix component may contain a liquid matrix component as long as it is solid.

  In addition, after forming a dispersion by combining a water-soluble matrix component, an olefinic thermoplastic resin (A) composed of an amorphous polymer and a thermoplastic resin (B) having polarity, as described later, as appropriate. Fine particles (resin fine particles and the like) modified with a modifier can be formed by a method such as elution or washing. These matrix components are components that are not compatible with the amorphous olefin-based thermoplastic resin (A) and the polar thermoplastic resin (B), and are olefin-based thermoplastics composed of an amorphous polymer. Although it will not specifically limit if melt-kneading with resin (A) and the thermoplastic resin (B) which has polarity is possible, It is preferable that it is water-soluble. That is, when the matrix component is a water-soluble matrix component, the matrix can be removed from the dispersion with water, which is economically and environmentally advantageous. As these matrix components, those described in JP-A-2005-162797 can also be used.

Specific water-soluble matrix components include, for example, water-soluble polymers [for example, polyalkylene glycols], depending on the type of thermoplastic resin and modifier as described in JP-A-2005-162797. And water-soluble polymers such as vinyl alcohol polymers; saccharides or derivatives thereof (eg, monosaccharides (eg, glucose), oligosaccharides, polysaccharides (eg, starch), sugar alcohols, etc.)). These matrix components may be used alone or in combination of two or more.
The matrix component may be composed of at least an oligosaccharide (C1-1) or a polysaccharide (C1-2) having a cyclic structure. Since the oligosaccharide is a saccharide, it can be easily removed from the dispersion by elution compared to the water-soluble polymer and the like, and the productivity of fine particles described later can be increased. JP, 2005-162797, A can also be referred to for the matrix ingredient constituted by oligosaccharide.

(C1-1) Oligosaccharide Oligosaccharide (C1-1) is composed of a homo-oligosaccharide obtained by dehydration condensation of 2 to 10 monosaccharides via a glycosidic bond, and at least two kinds of monosaccharides and / or sugar alcohols. It is roughly classified into hetero-oligosaccharides dehydrated and condensed via 2 to 10 molecule glycosidic bonds. Examples of the oligosaccharide (C1-1) include disaccharides to decasaccharides, and disaccharides to hexasaccharides are usually used.

  In order to effectively disperse the thermoplastic resin and the auxiliary component by kneading, it is desirable that the oligosaccharide has a high viscosity. Specifically, when measured at a temperature of 25 ° C. using a B-type viscometer, the viscosity of a 50 wt% aqueous solution of oligosaccharide is, for example, 1 to 500 Pa · s, preferably 2 to 250 Pa · s (eg 3 ˜100 Pa · s), more preferably about 4 to 50 Pa · s (for example, 6 to 50 Pa · s).

  The melting point or softening point of the oligosaccharide (C1-1) is determined by the heat distortion temperature (for example, amorphous) of the olefinic thermoplastic resin (A) made of an amorphous polymer and the polar thermoplastic resin (B). Higher than the melting point or softening point of Visible Olefin-based Thermoplastic Resin (A) and Polarized Thermoplastic Resin (B), Vicat softening point defined in JIS K 7206). In general, an oligosaccharide anhydride exhibits a high melting point or softening point. The temperature difference between the melting point or softening point of the oligosaccharide and the thermal deformation temperature of the olefinic thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having polarity is, for example, 1 to 80 ° C. The temperature is preferably about 10 to 70 ° C, more preferably about 15 to 60 ° C.

The water-soluble matrix component (C) may be composed of oligosaccharides, but in order to increase the melt viscosity, a polysaccharide having a cyclic structure (water-soluble polysaccharide) may be used alone or in combination with oligosaccharides. (C1-2) Cyclic polysaccharide In a water-soluble polysaccharide having a cyclic structure (sometimes simply referred to as cyclic polysaccharide), the cyclic structure (cyclic skeleton, cyclic unit, cyclic site) constitutes the polysaccharide. It may be a ring formed by a plurality of glycose units [usually glucose units (particularly D-glucose)] formed by glucoside bonding (or glucosylation). That is, in this specification, the cyclic structure means a ring formed of a plurality of glycolose units (and glucoside bonds), and does not mean a monosaccharide ring such as a glucose ring.

Such a cyclic polysaccharide has a relatively high molecular weight and a high melt viscosity as compared with an oligosaccharide and the like, and also exhibits water solubility because of its cyclic structure. When a cyclic polysaccharide is used, a high shear viscosity can be maintained in melt-kneading, so melt-kneading can be performed without impairing melt-kneading properties, and water-soluble, so that it can be easily removed with water or the like. In particular, when a cyclic olefin monomer polymer is used for the amorphous olefin-based thermoplastic resin (A), the molten amorphous olefin-based thermoplastic resin (A) is melted and kneaded in the fine kneading process. Since the melt viscosity is increased, the particle size of the obtained fine particles may be increased, and the dispersion of the particle size distribution may be increased.
When the water-soluble matrix component (C) is composed of the cyclic polysaccharide (C1-2), the melt viscosity of the water-soluble matrix component (C) can be increased, and the particle size is small and the particle size varies. This is advantageous when trying to obtain small particles.

  In the polysaccharide, the cyclic structure only needs to be composed of a plurality of glucoside bonds, may be composed of α-glucoside bonds or β-glucoside bonds, and may be generally composed of α-glucoside bonds. Good.

  The average degree of polymerization of the cyclic structure (per one cyclic structure) (number average degree of polymerization, average number of glucoside bonds forming the cyclic structure, average degree of polymerization of the glycose unit forming the cyclic structure) is, for example, 10 or more (for example, 10 or more), preferably 12 or more (for example, about 12 to 300), more preferably 14 or more (for example, about 14 to 100).

  Further, the glucoside bond constituting the cyclic structure is usually a ring formed of at least 1,4-glucoside bond (particularly α-1,4-glucoside bond), and 1,4-glucoside bond (particularly, , Α-1,4-glucoside bond) and 1,6-glucoside bond (particularly α-1,6-glucoside bond).

In such a ring containing 1,6-glucoside bond, the average number of 1,6-glucoside bonds in the cyclic structure (per one cyclic structure) may be 1 or more (for example, about 1 to 700), For example, it may be 1 to 300 (for example, 1 to 200), preferably 1 to 100 (for example, 1 to 50), more preferably 1 to 20 (for example, 1 to 10).
Moreover, the cyclic polysaccharide should just have at least 1 cyclic structure (cyclic unit), and may have a some cyclic structure.

  The average degree of polymerization of the cyclic polysaccharide (number average degree of polymerization, total average degree of polymerization, average degree of polymerization of the whole polysaccharide) is, for example, 14 or more (for example, 14 to 15000), preferably 17 or more (for example, 17 -10000), more preferably 20 or more (for example, 20-8000).

  The cyclic polysaccharide may be derivatized (or modified). For example, a cyclic polysaccharide has a hydroxyl group (alcoholic hydroxyl group) derivatized [eg, etherification (eg, alkyl etherification such as methyl etherification; hydroxyalkyl etherification such as hydroxyethyl etherification, hydroxypropyl etherification, etc.) Glycerylated, esterified, grafted, cross-linked, etc.] derivatives. These cyclic polysaccharides may be used alone or in combination of two or more.

  The water-soluble polysaccharide having a typical cyclic structure has (1) a cyclic structure (or a cyclic unit) and an acyclic structure (acyclic skeleton, acyclic unit acyclic part) bonded to the cyclic structure. And a polysaccharide having an average degree of polymerization of 50 or more, and (2) a polysaccharide having one cyclic structure formed of 14 or more α-1,4-glucoside bonds in the molecule.

(Cyclic polysaccharide (1))
In the cyclic polysaccharide (1), the cyclic structure may be a ring formed by an α-1,4-glucoside bond and an α-1,6-glucoside bond. Further, the average degree of polymerization (number average degree of polymerization) of the cyclic structure (per one cyclic structure) may be, for example, about 10 to 500, preferably about 12 to 300, and more preferably about 14 to 100. When the cyclic structure has an α-1,6-glucoside bond, the average number of α-1,6-glucoside bonds in the cyclic structure (per one cyclic structure) is, for example, 1 or more (for example, 1 to 200), Preferably it may be about 1-100, more preferably about 1-50.

  In addition, the average degree of polymerization (number average degree of polymerization) of cyclic polysaccharide (1) should just be 50 or more, for example, 50-10000, Preferably it is 60-7000, More preferably, it is about 70-5000. Good.

  The cyclic polysaccharide (1) may have one or a plurality of acyclic structures, and usually has a plurality (for example, about 2 to 1000, preferably about 3 to 500) of acyclic structures. May be. The average degree of polymerization (number average degree of polymerization) per such acyclic part (or part other than the cyclic structure of the cyclic polysaccharide (1)) is, for example, 10 or more (for example, about 10 to 30), preferably May be about 10-20. Moreover, the average degree of polymerization (number average degree of polymerization) of the whole non-cyclic part should just be 10 or more, for example, 40 or more (for example, about 50-5000), Preferably about 100-3000 may be sufficient. In particular, the acyclic moiety is often branched from an α-1,6-glucoside-bonded glycose (particularly glucose) unit.

  In the cyclic polysaccharide (1), the hydroxyl group (alcoholic hydroxyl group) may be derivatized (for example, etherified, esterified, grafted, etc.).

  Such cyclic polysaccharide (1) includes a so-called “cluster dextrin” polysaccharide. Such polysaccharides (1) are synthesized by, for example, saccharides (eg, starch, partially decomposed starch, amylopectin, glycogen, waxy starch, high amylose starch, soluble starch, dextrin, starch hydrolysate, and phosphorylase). It may be obtained by reacting an enzyme (branching enzyme, D enzyme, cyclodextrin glucanotransferase, etc.) capable of forming a cyclic structure by acting on a saccharide with at least one substrate selected from amylopectin. . JP-A-8-134104 and the like can be referred to for details of such cluster dextrin and the production method thereof.

(Cyclic polysaccharide (2))
In the cyclic polysaccharide (2), the cyclic structure may be a ring formed of at least an α-1,4-glucoside bond, and includes an α-1,4-glucoside bond and an α-1,6-glucoside bond. It may be a ring formed. In the polysaccharide (2), the average degree of polymerization (number average degree of polymerization) of the cyclic structure may be 14 or more, for example, 14 to 5000, preferably 15 or more (for example, about 15 to 3000), It may be 17 or more (for example, about 17 to 1000). When the cyclic structure has an α-1,6-glucoside bond, the average number of α-1,6-glucoside bonds in the cyclic structure is, for example, 1 to 500, preferably 1 to 300, more preferably about 1 to 100. It may be.

  The cyclic polysaccharide (2) may have an acyclic structure (for example, a straight chain structure) as long as it has the cyclic structure, but it is usually constituted (or formed) only by the cyclic structure. It may be a cyclic polysaccharide.

In the cyclic polysaccharide (2), the hydroxyl group (alcoholic hydroxyl group) may be derivatized (for example, etherified, esterified, grafted, crosslinked).
Such a cyclic polysaccharide (2) includes a so-called “cycloamylose (or cycloamylose)” polysaccharide. Such cyclic polysaccharide (2) is, for example, linear α-1,4-glucan or a saccharide containing this glucan (for example, maltooligosaccharide, amylose, amylopectin, glycogen, starch, waxy starch, high amylose starch) Soluble starch, dextrin, starch debranch, partially hydrolyzed starch, amylose synthesized with morpholylase, and at least one selected from these derivatives) and an enzyme capable of forming cyclic polysaccharide (2) ( For example, the enzyme such as D enzyme can be obtained by reacting in the presence of phosphorylase and glucose 1-phosphate, if necessary.

  In the reaction, when a substrate having an α-1,6-glucoside bond is used as a substrate, an enzyme capable of cleaving the α-1,6-glucoside bond (for example, isoamylase, pullulanase, etc.) is present. You may go on. JP-A-8-311103 and the like can be referred to for details on such cycloamylose and its production method.

  These polysaccharides may be used alone or in combination of two or more. For example, the cyclic polysaccharide (1) and the cyclic polysaccharide (2) can be used in combination, and in particular, at least the cyclic polysaccharide (1) (or cluster dextrin) can be preferably used.

  The ratio between the cyclic polysaccharide and the oligosaccharide is, for example, the former / the latter (weight ratio) = 99/1 to 5/95, preferably 95/5 to 10/90, more preferably 90/10 to 20/80. (E.g., 85/15 to 25/75), particularly 80/20 to 30/70 (e.g., 70/30 to 40/60), and usually about 99/1 to 50/50. Also good.

The viscosity of a 50% by weight aqueous solution of hydrocyclic polysaccharide (C1-2) is, for example, 5 Pa · sec or less (eg, 1 to 5 Pa · sec), preferably (eg, 2 to 4 Pa · sec) at a temperature of 25 ° C. Degree. Thus, since the aqueous solution viscosity is low, when cyclic polysaccharide (C1-2) is used, combined with the high solubility in water, the elution efficiency with water can be increased.

  The water-soluble matrix component (C) may further contain a water-soluble plasticizing component (C2) for plasticizing the oligosaccharide (C1-1) and the cyclic polysaccharide (C1-2). When the oligosaccharide (C1-1) or cyclic polysaccharide (C1-2) is combined with the water-soluble plasticizing component (C2), the viscosity of the water-soluble matrix component (C) in kneading with the thermoplastic resin (A) Can be adjusted.

(C2) Water-soluble plasticizing component As the water-soluble plasticizing component (C2), the oligosaccharide (C1-1) and the cyclic polysaccharide (C1-2) can be hydrated to develop a phenomenon of varicella. For example, sugars, sugar alcohols and the like can be used. As these plasticizing components (C2), those described in JP-A-2005-162797 can be used.
Moreover, these plasticizing components (C2) can be used individually or in combination of 2 or more types.

(A) Saccharides As the saccharides, monosaccharides and / or disaccharides are usually used in order to effectively plasticize the oligosaccharide (C1-1). These saccharides can be used alone or in combination of two or more.

(B) Sugar alcohol The sugar alcohol may be a chain sugar alcohol such as alditol (glycitol) or a cyclic sugar alcohol such as inosit. Usually, a chain sugar alcohol is used. The These sugar alcohols can be used alone or in combination of two or more.

  Examples of chain sugar alcohols include tetritol, pentitol, xylitol, hexitol and the like.

Of these sugar alcohols, erythritol, pentaerythritol, arabitol, ribitol, xylitol, sorbitol, dulcitol, mannitol and the like are preferable. Often the sugar alcohol comprises at least one sugar alcohol selected from erythritol, pentaerythritol, xylitol, and sorbitol.
The melting point or softening point of the matrix component (C) may be equal to or higher than the heat deformation temperature of the olefin thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having polarity, and heat deformation. It may be below the temperature. The olefinic thermoplastic resin (A) made of an amorphous polymer, the polar thermoplastic resin (B), and the matrix component (C) may be melted or softened at least at the kneading temperature (or molding processing temperature).

  For example, the temperature difference between the melting point or softening point of the matrix component (C) and the thermal deformation temperature of the olefinic thermoplastic resin (A) and the thermoplastic resin (B) made of an amorphous polymer is 0. You may select in the range of -100 degreeC, for example, 3-80 degreeC (for example, 3-55 degreeC), Preferably it is 5-60 degreeC (for example, 5-45 degreeC), More preferably, it is 5-40 degreeC (for example, 10 to 35 ° C.). In addition, when the temperature difference between the melting point or softening point of the matrix component (C) and the heat distortion temperature of the olefinic thermoplastic resin (A) and the thermoplastic resin (B) made of an amorphous polymer are small (For example, when the temperature difference is about 0 to 20 ° C.), there is an advantage that the dispersed form can be fixed in a short time by the matrix component (C) (for example, sugar component) having a high solidification rate.

  Further, the melt flow rate of the matrix component (C) (for example, the component containing the oligosaccharide (C1-1) and the plasticizing component (C3)) is, for example, an olefin-based thermoplastic thermoplastic made of an amorphous polymer. Thermal deformation temperature of resin (resin component, etc.) (A) (for example, melting point or softening point of olefin-based thermoplastic resin (A) made of amorphous polymer and polar thermoplastic resin (B), Vicat softening When the melt flow rate defined in JIS K 7210 is measured at a temperature 30 ° C. higher than the point), it is 1 or more (for example, about 1 to 40), preferably 5 or more (for example, about 5 to 30), more preferably It may be 10 or more (for example, about 10 to 20).

  In the matrix component (C), the proportion (weight ratio) of the plasticizing component (C2) is such that the plasticizing component is not localized due to aggregation due to the melt kneading, and the oligosaccharide (C1-1) is efficiently Can be selected from, for example, oligosaccharide (C1-1) / plasticizing component (C2) = 99/1 to 50/50, preferably 95/5 to 60/40, more preferably 90/10. About 70/30.

  The ratio (weight ratio) between the dispersed phase (the total amount of the olefinic thermoplastic resin (A) made of an amorphous polymer (A) and the thermoplastic resin (B) having polarity) and the matrix component (C) is determined for each thermoplastic. It can be selected according to the type and viscosity of the resin and matrix components and is not particularly limited, but is usually an amount that does not impair the moldability, for example, the former / the latter = 55/45 to 1/99, preferably 50/50 to 5 / 95, more preferably about 45/55 to 10/90.

[Production method of fine particles]
The fine particles of the present invention can be prepared by using the forced emulsification method as described above. Specifically, the matrix component (C) is obtained by removing the matrix component (C) from a dispersion composed of the olefinic thermoplastic resin (A) made of the amorphous polymer and the thermoplastic resin (B) having polarity.

(Method for producing dispersion)
As long as the dispersion can disperse in the matrix component (C) a particulate dispersed phase composed of an olefinic thermoplastic resin (A) made of an amorphous polymer and a thermoplastic resin (B) having polarity, Although not particularly limited, it can be usually prepared by kneading the olefinic thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having polarity and the matrix component (C).

  Examples of the kneading method of the olefinic thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having polarity and the matrix component (C) include (i) an amorphous polymer. A method of kneading a thermoplastic resin (A) having polarity, a thermoplastic resin (B) having polarity and a matrix component (C), (ii) an olefin thermoplastic resin (A) comprising an amorphous polymer And a polar thermoplastic resin (B) mixture, and this mixture and the matrix component (C) are kneaded.

The dispersion of the present invention can be prepared by any of these methods. In particular, the olefin-based thermoplastic resin (A) made of an amorphous polymer, the polar thermoplastic resin (B), and the matrix. The method (i) for kneading the component (C) can be suitably used.
As a mixing method, a conventional method, for example, a method of dry blending each component, a method of melt mixing (melt blending) each component, a method of dissolving (or dispersing) each component in a solvent and removing the solvent, etc. Available.
(Melt mixing with matrix component (C))
The kneading (melt mixing, melt kneading) of the olefinic thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having polarity and the matrix component (C) is a conventional kneader (for example, Single screw or twin screw extruder, kneader, calender roll, etc.).
The melt-kneaded composition (dispersion) is preferably processed (molded) into a strand shape, a rod shape, a sheet shape, a film shape, or the like.

  In addition, kneading | mixing temperature and shaping | molding processing temperature can be suitably set according to the raw material (for example, a thermoplastic resin, a matrix component) used, for example, 90-300 degreeC, Preferably it is 110-260 degreeC ( For example, it is about 130-250 degreeC, More preferably, it is about 140-240 degreeC (for example, 150-240 degreeC), Especially about 170-230 degreeC (for example, 180-220 degreeC). In order to avoid thermal decomposition of the matrix components (for example, oligosaccharides and plasticizing components), the kneading temperature and the molding processing temperature may be 230 ° C. or lower (for example, about 160 to 220 ° C.). The kneading time may be selected from the range of, for example, 10 seconds to 1 hour, and is usually about 30 seconds to 45 minutes, preferably about 1 to 30 minutes (for example, 3 to 20 minutes).

  The melt obtained by kneading and / or molding (for example, a preform) may be appropriately cooled as necessary. In the dispersion thus obtained, the matrix component (C) forms a continuous phase in the sea-island structure, and the thermoplastic resin having polarity with the olefinic thermoplastic resin (A) made of an amorphous polymer. (B) has a phase-separated structure in which the dispersed phase is independently formed as a dispersed phase.

  The matrix component can be quickly removed from such a dispersion by elution or extraction, and the dispersed phase (the olefinic thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B Can be obtained as particles (fine particles, composite particles). The method for removing the matrix component from the dispersion is not limited as long as the matrix component can be removed, but usually the matrix component is often eluted from the dispersion. It is preferable to use water (particularly water alone) as an elution solvent.

  Elution of the matrix component (C) is carried out by a conventional method, for example, by immersing and dispersing the dispersion (or preform) in the solvent (particularly an aqueous solvent) to elute or wash the matrix component (solvent It can be performed by shifting to When the dispersion (or preform) is immersed in a solvent, the matrix components that form the matrix of the dispersion are gradually eluted, and the dispersed phase (or particles or cake) is dispersed in the eluate. In order to promote dispersion and elution of the matrix component, stirring or the like may be appropriately performed.

  The composite particles can be recovered from the dispersion liquid in which the particles are dispersed using a conventional separation (recovery) method such as filtration or centrifugation.

  The separated composite particles (cake after solid-liquid separation) may be dried. The average particle size (for example, number average particle size) of the composite particles (or dispersed phase) of the present invention can be selected from the range of about 1 μm to 5000 mm (for example, 2 to 100 μm), for example, 3 to 40 μm, preferably 4 It may be ˜30 μm. In addition, an average particle diameter shows a volume average particle diameter.

  In the present invention, the particle size distribution can be reduced by making the particle size of the composite particles (or dispersed phase) uniform. When the oligosaccharide (C1-1) and the plastic component (C2) are used as the water-soluble matrix component (C), the coefficient of variation (%) of the average particle diameter of the composite particles (or dispersed phase) ([particles Standard deviation of diameter / average particle diameter] × 100, for example, standard deviation of volume average particle diameter / volume average particle diameter) is, for example, 90 or less (for example, about 50 to 90), preferably 90 or less (for example, 55 to 85). Degree), more preferably 80 or less (for example, about 60 to 80).

  When the plastic component (C2) is added to the combination of the cyclic polysaccharide (C1-2) or the oligosaccharide (C1-1) and the cyclic polysaccharide (C1-2) as the water-soluble matrix component (C) Is a variation coefficient (%) of average particle diameter ([standard deviation of particle diameter / average particle diameter] × 100, for example, standard deviation of number average particle diameter / number average particle diameter) is, for example, 60 or less (for example, 10 to 10). 60 or less), preferably 55 or less (for example, about 5 to 55), more preferably 50 or less (for example, about 10 to 50).

The ratio of the volume average particle diameter to the number average particle diameter, that is, the volume average particle diameter / number average particle diameter is 1.4 or less, preferably 1.3 or less, more preferably 1.25 or less. Yes (refractive index of olefinic thermoplastic resin (A) made of amorphous polymer and polar thermoplastic resin (B))

  The olefinic thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having polarity may have different refractive indexes. According to this aspect, since the refractive index is different between the skin and the core of the composite particles, composite particles having high light scattering properties can be obtained. That is, the light passing through the composite particles is irregularly reflected at the interface between the skin layer and the core layer having different refractive indexes. As a result, the light scattering property of the composite particles can be made higher than that of single layer particles. On the other hand, unnecessary irregular reflection inside the particles can be suppressed by using the olefinic thermoplastic resin (A) made of the amorphous polymer of the present invention as the core layer of the composite particles.

  As a result, it is possible to obtain particles with high light transmittance despite having high light scattering properties. That is, the non-uniformity of the refractive index inside the single layer particle or inside the core layer of the composite particle causes light to diffusely reflect inside the particle, making it difficult for light to escape from the inside of the particle. As a result, light is attenuated inside the particle, reducing the light transmittance of the particle. For this reason, particles having a small difference in refractive index are preferable inside the single-layer particle or inside the core layer of the composite particle. Many crystalline polymers have a crystalline portion and an amorphous portion in terms of microstructure. The refractive index of light is different between the crystalline part and the amorphous part. For this reason, when a crystalline polymer is used inside a single-layer particle or inside a core layer of a composite particle, light is diffusely reflected at the crystal part and the amorphous part, and particles with high light transmittance are obtained. I can't.

On the other hand, when the single-layer particles using the olefinic thermoplastic resin (A) simply made of an amorphous polymer are used, the difference in refractive index between the crystalline part and the amorphous part can be avoided, and the light transmittance can be avoided. High particles can be obtained. However, the light scattering property is low.
In the composite particle of the present invention, light is reflected and refracted at the interface between the core layer and the skin layer of the composite particle by making the refractive index of the core layer and the shell layer different. Furthermore, because it uses an olefinic thermoplastic resin (A) made of an amorphous polymer, light that has entered the core layer easily passes through the core layer without extra reflection or refraction inside the core layer. it can. In this way, both light scattering and light transmittance can be achieved.

  In this case, it is necessary for the core layer and the shell layer to have different refractive indexes in order to obtain reflection and refraction at the interface between the core layer and the shell layer. The refractive index is strongly influenced by the refractive index of the plastic constituting each of the core layer and the shell layer. The refractive index of the polymer constituting each of the core layer and the shell layer strongly influences the refractive index of the plastic constituting each, but is not a completely dominant factor. Therefore, it is necessary that the olefin thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having a polarity have different refractive indexes, but the olefin made of an amorphous polymer. It is not essential that the polymer constituting the thermoplastic resin (A) is different from the polymer constituting the polar thermoplastic resin (B).

  For example, the polymer constituting the olefinic thermoplastic resin (A) made of an amorphous polymer and the polymer constituting the thermoplastic resin (B) having polarity are made the same or the same type of polymer, A mode in which a plasticizer having a function of adjusting the refractive index (for example, a plasticizer having an aromatic ring) is added to the thermoplastic resin (B) having the above-mentioned is included in the present invention. However, in order to form composite particles having a uniform shell layer by the forced emulsification method, the polymer constituting the olefinic thermoplastic resin (A) made of an amorphous polymer (A) and a polar thermoplastic resin ( It is preferable that the polymers constituting B) are different. However, the forced emulsification method may not be used as a method for producing the composite particles of the present invention. For example, when a shell layer is formed by coating or the like on a single layer of fine particles obtained by the forced emulsification method, a plasticizer for adjusting the refractive index is added to the same or the same type of polymer. It is good also as a thermoplastic resin (B) which has polarity.

  The difference in refractive index between the olefinic thermoplastic resin (A) made of an amorphous polymer and the polar thermoplastic resin (B) is the refractive index of the olefinic thermoplastic resin (A) made of an amorphous polymer. Assuming that 100% is about 2%, a sufficient light scattering property can be obtained. Therefore, the ratio of the refractive index of the thermoplastic resin (B) having polarity to the refractive index of the olefinic thermoplastic resin (A) constituting the fine particles is 0.98 or less, or 1.02 or more. The object of the present invention is achieved. Preferably, the difference is 3% or more when the refractive index of the olefinic thermoplastic resin (A) made of an amorphous polymer is 100%. Either the olefin-based thermoplastic resin (A) made of an amorphous polymer or the polar thermoplastic resin (B) may have a higher refractive index. Speaking from the laws of physics of light, the higher the refractive index of the thermoplastic resin (B), the more the refraction angle at the interface between the shell layer and the core layer of the composite particles is advantageous. Even when the refractive index of the thermoplastic resin (B) having polarity is smaller than the refractive index of the olefin thermoplastic resin (A) made of an amorphous polymer, composite particles having high light scattering properties could be obtained. .

  Further, as described above, various thermoplastic resins can be used as the thermoplastic resin (B) having polarity, but in order to form a uniform shell layer, those having a certain degree of polarity are preferable. And it is preferable that a crystal | crystallization part and an amorphous part do not exist also in shell layer itself for the same reason as the olefin type thermoplastic resin (A) which consists of an amorphous polymer. Therefore, for the light scattering property, the thermoplastic resin (B) having polarity is preferably amorphous while having polarity, and polymethyl methacrylate is most preferred.

(Particle properties)
The composite particles obtained from the above-described method and comprising the olefinic thermoplastic resin (A) made of an amorphous polymer and the thermoplastic resin (B) having polarity have a water absorption of 0.5% by weight ( 5,000 ppm) or less, more preferably 0.3 wt% (3,000 ppm) or less, and most preferably 0.25 wt% (2,500 ppm) or less.

  Further, the obtained composite particles are mixed with a two-component epoxy adhesive (manufactured by Konishi Co., Ltd., BondQuick 5) so that the weight ratio of the adhesive / particles is 80/20, and cured. The aggregated fracture strength of the obtained 2 mm thick plate-like sample in the tensile test at an initial test piece length of 20 mm and a crosshead speed of 10 mm / min is not a composite particle as a particle to be mixed but a particle made of a cyclic olefin resin alone It may be 20% or higher, more preferably 25% or higher, and most preferably 30% or higher.

  Speaking of optical properties, dispersion obtained by dispersing the obtained composite particles in a transparent solvent in which at least the resin (B) having a polarity forming a shell does not dissolve so that the volume concentration is 0.1 wt% The light transmittance of the dispersion measured after preparing a liquid and correcting the light transmittance when measured with only the solvent to be 100% may be 80% or more, more preferably May be 85% or more, most preferably 90% or more.

  Further, the Haze value of the dispersion measured in the same manner as the light transmittance described above may be 60% or more, more preferably 65%, and most preferably 70% or more.

  The composite composite particles of the present invention can be used for the formation of a structural material composed of a light scattering agent having excellent light scattering properties and light transmittance, or a binder such as an epoxy resin with low water absorption.

(Examples 1, 3, and 4)
Using a Henschel mixer (Mitsui Mining Co., Ltd., “FM type 20L”), the resin (A), resin (B), and matrix component (C) were mixed in the solid state with the composition shown in Table 1, After melt-kneading using a Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) under the conditions shown in Table 2, the mixture was cooled to obtain a blocky resin composition, and then cut into about 5 mm squares.

  The obtained dispersion (cut product) was immersed in pure water at 25 ° C. to obtain a suspension solution of composite particles. Using a membrane membrane (pore diameter: 0.45 μm, made of polyvinylidene fluoride), insolubles were filtered off from the suspension to collect resin composite particles. The recovered composite particles were dispersed in distilled water 20 times by weight with respect to the composite particles, and subjected to ultrasonic treatment for 5 minutes in an ultrasonic bath to obtain a suspension. Thereafter, the membrane particles (pore size 0.45 μm, made of polyvinylidene fluoride) were again used to separate insolubles from the suspension, and composite particles were collected.

 The collected composite particles were left in a hot air dryer and dried at 45 ° C. for 8 hours, and then pulverized using an agate mortar and a pestle until no agglomerated portion was left. Table 3 and Table 4 show the characteristics of the obtained composite particles. Each characteristic was evaluated or measured as follows.

(Example 2)
Composite particles were obtained in the same manner as in Example 1 except that the melt kneading was performed at a temperature of 220 ° C. and a rotation speed of 192 rpm using a continuous kneader (KRC S-1 Kneader manufactured by Kurimoto Steel Works). .

(Comparative Example 1)
Composite particles were obtained in the same manner as in Example 1 except that only the resin (A) was used as the resin component.

(Comparative Example 2)
Composite particles were obtained in the same manner as in Example 1 except that only the resin (B) was used as the resin component.
Using the following measurement methods, the properties of the examples and comparative examples implemented above were measured.

(Particle appearance and average particle size)
The obtained particles were observed with a scanning electron microscope (manufactured by JEOL Ltd., FE-SEM, JSM-6700F) to obtain photographs of the surface shape and the overall shape. Using the obtained scanning electron micrograph, draw a rectangle of any size so that at least 200 particles are included on the photograph, and measure the particle diameter of all particles present in the rectangle when converted to a true sphere. did. A volume average particle size and a number average particle size were obtained from the obtained at least 200 particle sizes. The obtained results are shown in Table 3.

(Structure observation of composite type composite particles)
The obtained particles are mixed with an epoxy resin adhesive (manufactured by Konishi Co., Ltd., Bondquick 5) to prepare a bowl-like material in which the composite particles are dispersed, and the thickness is about 0.05 μm to 0 by a microtome. After cutting into 2 μm ultra-foil slices, the composite particles are stained with a staining agent (osmium acid, ruthenium acid, etc.) that can be used to stain and separate the resin (A) and the resin (B). The structure was observed using a microscope (manufactured by JEOL Ltd., TEM, JEM-1200EXII). The observation results are shown in Table 3. For reference, a transmission electron micrograph of the composite composite particle obtained in Example 2 in a stained state (cross section of the particle) is shown in FIG.

(Measurement of glass transition temperature)
Cyclic olefin resin: cycloolefin copolymer (manufactured by Ticona Co., Ltd., cyclic polyolefin resin TOPAS 5013) DSC (thermal scanning calorimeter; heat flux type) Seiko Electronics Co., Ltd. The temperature was raised at 200 ° C. for 1 minute, lowered at 20 ° C./min, held at −50 ° C. for 1 minute, measured at 20 ° C./min to 200 ° C., and the glass transition temperature with a second run. Was measured.

(Water absorption rate of particles)
The water absorption of the obtained particles was measured at a heating furnace temperature of 200 ° C. using a Karl Fischer moisture measuring device (manufactured by Dia Instruments, trace moisture measuring device CA100 + moisture vaporizer VA100). The results are shown in Table 4.

(Adhesiveness with polar matrix)
Two-part epoxy adhesive (Konishi Co., Ltd., Bondquick 5) 2.0 g (each liquid 1.0 g) and 0.5 g of the obtained particles were put on a Teflon (registered trademark) pan and sheared. Mixed and poured into a mold before the adhesive hardened. Thereafter, the mold was allowed to stand at room temperature for 48 hours to obtain a cured plate-like sample having a thickness of 2 mm. The obtained sample was cut into a strip shape having a width of 5 mm and a length of 4 cm, and the tensile fracture strength was measured using a tensile tester (Tensilon RTA-500, manufactured by Orientec Co., Ltd.). It was used as an index of adhesion. The tensile test was performed at an initial test piece length of 20 mm and a crosshead speed of 10 mm / min. The measurement was performed with the number of repetitions n = 5, and after removing data with obvious measurement deficiencies, the average value was used as the measurement value. Table 4 shows the measurement results.

(Light transmittance and light scattering)
The obtained particles are mixed with the solvent shown in Table 3 so that the volume concentration is 0.1% with respect to the solvent, and the mixture is treated in an ultrasonic dispersion tank for 20 minutes to obtain a liquid in which the particles are dispersed. Obtained.

  Within 10 minutes after the completion of the dispersion treatment, the dispersion is collected in a Pyrex (registered trademark) cell having an optical path length of 3 mm, and a total light transmission amount (light transmittance) is measured using a haze meter 300A manufactured by Nippon Denshoku Industries Co., Ltd. ) And Haze values were measured. Prior to the measurement of the dispersion, the light transmittance obtained by collecting the solvent used alone in a Pyrex (registered trademark) cell having an optical path length of 3 mm and performing the measurement is set so that the light transmittance is 100%. The measured value of the dispersion was corrected.

  For each measurement, the same solution collected in the measurement cell was used to measure twice at 1 minute intervals. If the measured value showed a difference of 5% or more, poor dispersion or sedimentation of particles occurred. The measurement was again performed after the dispersion treatment was performed again. The measurement was performed with the number of repetitions n = 3, and the average value was used as each measurement value. Table 4 shows the solvent used for the measurement, the light transmittance of the solvent, and the measurement results.

なお、実施例及び比較例では、下記の成分を用いた。

In the examples and comparative examples, the following components were used.

(A) Amorphous olefin resin A1: Cyclic olefin resin: Cycloolefin copolymer (manufactured by TAP, cyclic polyolefin resin TOPAS (registered trademark) 5013S-04
Glass transition temperature 140 ° C
Total light transmittance 91%
Refractive index 1.53
A2: Cyclic olefin resin: cycloolefin copolymer (manufactured by TAP, cyclic polyolefin resin TOPAS (registered trademark) 8007F-04
Glass transition temperature 80 ℃
Total light transmittance 91%
Refractive index 1.53

(B) Polarized thermoplastic resin B1: Polymethyl methacrylate resin (manufactured by Asahi Kasei Chemicals Corporation, Delpet 720V) Refractive index 1.49
B2: Polyamide (nylon 12) resin (Daicel Degussa, Bestamide L1800)
B3: Ethylene-vinyl alcohol copolymer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., Soarnol DC3212)

(C) Matrix component Oligosaccharide C1-1: Starch sugar (Towa Kasei Kogyo Co., Ltd., reduced starch saccharified product PO-10)
Cyclic polysaccharide C1-2: Cluster dextrin (manufactured by Nippon Shokuhin Kako Co., Ltd.)
Sugar alcohol (water-soluble plasticizing component) C2-1: sorbitol (manufactured by Towa Kasei Kogyo Co., Ltd., Sorbit (registered trademark)).

The transmission electron micrograph ((JEOL Co., Ltd. make, TEM, JEM-1200EXII) state which dye | stained the composite composite particle obtained in Example 2 (cross section of particle | grains)).
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Claims (6)

It is a substantially spherical fine particle comprising an olefinic thermoplastic resin (A) made of an amorphous polymer having a crystallinity of 5% by weight or less, and a thermoplastic resin (B) having polarity, and its number average particle diameter 1 to 5,000 μm, a composite particle having a core-shell structure in which the olefinic thermoplastic resin (A) is the core and the polar thermoplastic resin (B) is the shell. The ratio obtained by dividing the refractive index of the thermoplastic resin (B) having polarity by the refractive index of the olefinic thermoplastic resin (A) constituting the fine particles is 0.98 or less, or 1.02 or more. 2. Composite particles according to 1. The composite particles according to claim 1, wherein the weight ratio of the olefinic thermoplastic resin (A) and the thermoplastic resin (B) having polarity is in the range of 50/50 to 99/1. The composite particles according to claim 1, wherein the moisture absorption rate as particles is 0.5% by weight or less. The cohesive failure strength of the adhesive after curing when 20% by weight of fine particles are dispersed in the epoxy adhesive resin is improved by 20% or more compared to the case where particles made of the resin (A) alone are used. The composite particle according to claim 1. The composite particle according to claim 2, wherein the light transmittance measured by the following measurement method is 80% or more and the haze value is 60% or more.
(Light transmittance and haze value measuring method)
Pyrex (registered) with an optical path length of 3 mm by dispersing 0.1% by volume of particles in a solvent that does not dissolve the thermoplastic thermoplastic resin (B) having polarity and using a single beam photometer as defined in JIS K7361-1; Measurement is performed using a cell made of a trademark. However, the light transmittance when the measurement cell is filled with the solvent is set to 100%, and correction is performed prior to measurement.

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