JP2008291253A - Composite resin particle containing inorganic particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite resin particle (composite thermoplastic resin particle) of a core-shell structure containing inorganic particles (such as a metal oxide) unevenly distributed in the shell. <P>SOLUTION: A first thermoplastic resin, a second thermoplastic resin, inorganic particles (such as metal oxide particles) and auxiliaries such as a water-soluble polysaccharide are melt-kneaded to give a dispersion containing the composite resin particle composed of a core comprising the first thermoplastic resin and a shell comprising the second thermoplastic resin, where the inorganic particles can be unevenly distributed in the shell of the composite resin particle by selecting the combination of the first thermoplastic resin and the second thermoplastic resin, selecting the kinds of the auxiliaries, and the like. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a composite resin particle having a core-shell structure made of a thermoplastic resin, wherein inorganic particles such as metal oxide particles are unevenly distributed in the shell of the composite resin particle.

  Since the composite resin particles having a core-shell structure are composed of a plurality of organic solid substances (resins, etc.), they are composed of a single component (such as a single resin component) according to the characteristics of the organic solid substances (resins, etc.) Various functions that cannot be obtained with the formed particles can be imparted. For example, the cyclic polyolefin resin has excellent performance such as high light transmittance or low water absorption, but further improvement or impartment of resin properties can be expected by adopting a core-shell structure.

  On the other hand, as resin particles in which inorganic particles are combined, for example, toner or ink particles in which pigments are dispersed, cosmetic resin particles in which inorganic particles having ultraviolet absorbing ability are combined, and the like are used. In such composite resin particles, various characteristics can be effectively expressed by unevenly distributing the inorganic particles with respect to the resin particles. For example, colorants as high-concentration inorganic particles can be protected by encapsulating them in resin particles, and functional particles such as UV absorbers that may cause allergies are encapsulated in resin particles. Therefore, the risk of developing allergic symptoms can be greatly reduced even when used as a cosmetic. Moreover, the fluidity | liquidity and surface characteristics (charging characteristics etc.) of a resin particle can be improved by making a filler etc. adhere to the surface of a resin particle. Thus, by making the inorganic particles unevenly distributed in the resin particles in which the inorganic particles are combined, desired characteristics can be imparted to the resin particles, or the characteristics of the combined resin particles can be improved.

  Such inorganic particles are unevenly distributed as described above, and are contained in the composite resin particles having a core-shell structure, so that the core-shell resin particles can be made more efficient by, for example, imparting excellent properties to the core-shell resin particles. Expected to be well modified.

  As a method for obtaining the composite resin particles having the core-shell structure as described above, a seed emulsion polymerization method in which polymer particles are polymerized after synthesizing core polymer particles is the most common. 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 by seed emulsion polymerization. Yes.

  However, in such a seed emulsion polymerization method, the core polymer is limited to a polymer that can be polymerized in an emulsified state or a suspended state. In addition, since the seed emulsion polymerization method is a production method including a step of polymerizing a core polymer, the polymer particles having a core particle size exceeding 1 μm are stably produced in a state where the particle size distribution is narrow. Difficult to do. 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, and the types of polymers used for the shell are also limited. That is, such a seed emulsion polymerization method cannot be applied to a resin obtained by a condensation reaction, or a polymer that undergoes radical polymerization by a high-pressure method such as a high-pressure method polyolefin or cyclic polyolefin.

  Composite resin particles obtained by a method other than the seed emulsion polymerization method are also known. Japanese Patent Application Laid-Open No. 2005-162797 (Patent Document 2) discloses particles composed of a meltable organic solid component (A) (resin component or the like), and the organic solid component (A) is at least an oligosaccharide. A composite particle composed of a plurality of organic solid substances having different affinity for the water-soluble auxiliary component (B) containing (B1) is disclosed. In this document, the composite particle has a core-shell structure composed of a core portion containing the first organic solid substance (A1) and a shell portion containing the second organic solid substance (A2). It is described that it may be. In this document, the particulate dispersed phase composed of the organic solid component (A) containing a plurality of organic solid substances is composed of a water-soluble auxiliary component (B) containing at least an oligosaccharide (B1). It is described that the composite particles can be produced by a method of eluting the auxiliary component (B) from the dispersion dispersed in the prepared matrix.

  However, although it is described in this document that the dispersion may contain a filler or the like, a method for specifically including a filler or the like in a composite particle, and a method for uneven distribution are disclosed. It has not been. Further, in this document, for example, it is disclosed that an olefin resin or the like is used as an organic solid component, but specifically, there is no disclosure about a composite particle having a core-shell structure having an olefin resin as a core. There is also no disclosure of core-shell structured particles using a cyclic polyolefin resin.

Also known is a method in which inorganic particles are combined with resin particles regardless of the seed polymerization method. For example, Japanese Patent Laid-Open No. 2006-328218 (Patent Document 3) includes at least one kind of resin (A) and filler (B), and the resin (A) and filler (B) (metal). For forming a dispersed phase of the resin (A) containing the filler (B) in the emulsified medium (C) by melt mixing or kneading with the incompatible emulsified medium (C) with respect to the oxide or the like) The following formula ηR (ω) = η ^* C (ω) / η ^* A (ω)
(Where η ^* C (ω) is a dynamic viscoelasticity measurement at a temperature T and a frequency ω (sec ⁻¹ ) of the resin composition composed of the resin (A) and the filler (B). The shear viscosity is shown, and η ^* A (ω) shows the shear viscosity in the dynamic viscoelasticity measurement at the temperature T and the frequency ω (sec ⁻¹ ) of the resin (A), and the temperature T is 120 ° C. to 20 ° C. When the shear viscosity of the resin (A) is measured while raising the temperature every time, the value at a frequency of 35.4 sec ⁻¹ indicates the lowest temperature at which the value is 1000 Pa · s or less.
In the represented, and frequency ω1.12 ratio X = ηR (1.12) with .eta.r (omega) at .eta.r in ^{(sec -1)} (ω) and frequency ω62.9 ^{(sec -1)} / ηR ( A method of controlling the distribution state of the filler in the dispersed phase using the value of 62.9) as an index is disclosed.

  In this document, it is possible to generate resin particles containing at least the filler (B) under the condition that the X is 1.5 or less, and the filler (B) under the condition that the X exceeds 1.5. It is described that coated resin particles can be produced.

However, although it is described in this document that two or more kinds of resins can be used in combination in the resin (A), no specific example of combining two or more kinds is described, and the core-shell structure There is no mention about. In particular, there is no disclosure of core-shell structured particles using a cyclic polyolefin resin.
JP-A-7-70255 (Claims) JP 2005-162797 A (claims, paragraph number [0115]) JP 2006-328218 A (claims, paragraph number [0030])

  Accordingly, an object of the present invention includes a core-shell structure composite resin particle (composite thermoplastic resin particle) in which inorganic particles (metal oxide or the like) are unevenly distributed in the shell, and the composite resin particle as a dispersed phase. It is to provide a dispersion.

  As a result of intensive studies to solve the above problems, the present inventor has selected the kind of thermoplastic resin constituting the core and the shell, the composition of the matrix in which the composite resin particles are dispersed, and the like, and thereby the composite resin particle shell. The present inventors have found that inorganic particles can be unevenly distributed in (or the entire shell) and completed the present invention.

  That is, the composite resin particle of the present invention includes a core made of the first thermoplastic resin, and a shell that covers the core, made of a second thermoplastic resin different from the first thermoplastic resin. The composite resin particles having a core-shell structure including, wherein inorganic particles are unevenly distributed in the shell (or the entire shell).

  The first thermoplastic resin may be a hydrophobic polymer (for example, at least one selected from a cyclic polyolefin polymer and a styrene polymer), and the second thermoplastic resin has a polar group. Even a thermoplastic resin (for example, at least one selected from (meth) acrylic polymers, polyamide polymers, and vinyl alcohol polymers (for example, ethylene-vinyl alcohol polymers)). Good.

  In particular, the inorganic particles may be nanoparticles (nano-sized particles, for example, inorganic particles having an average primary particle diameter of 50 nm or less). The inorganic particles may be inorganic particles that have been subjected to a hydrophobic treatment, for example, inorganic particles that have been subjected to a hydrophobic treatment with a silicon-based surface treatment agent (silica, polyorganosiloxane, etc.).

  In the composite resin particles, the ratio of the first thermoplastic resin to the second thermoplastic resin may be about the former / the latter (weight ratio) = 30/70 to 99/1. Further, the ratio of the inorganic particles may be about 0.5 to 30% by weight with respect to the entire composite resin particles.

  In the representative composite resin particles of the present invention, the first thermoplastic resin is composed of at least a cyclic polyolefin polymer, the second thermoplastic resin is composed of at least a (meth) acrylic polymer, and is inorganic. Examples include composite resin particles whose particles are metal oxide particles having an average primary particle diameter of 50 nm or less.

  The present invention also includes a dispersion in which the composite resin particles are dispersed in an auxiliary agent incompatible with the first thermoplastic resin and the second thermoplastic resin. The auxiliary agent may be composed of at least one water-soluble polysaccharide selected from oligosaccharides and water-soluble polysaccharides having a cyclic structure. In particular, the auxiliary agent may further contain a water-soluble plasticizing component for plasticizing the water-soluble polysaccharide in addition to the water-soluble polysaccharide.

  The dispersion includes the composite resin particles in which inorganic particles are unevenly distributed in specific portions in accordance with the combination of the first thermoplastic resin and the second thermoplastic resin, the type of auxiliary agent, and the like. . The dispersion containing the composite resin particles includes the following dispersions.

A first thermoplastic resin composed of at least a cyclic polyolefin-based polymer; a second thermoplastic resin composed of at least a (meth) acrylic polymer; and a thermoplastic resin composition containing inorganic particles; and at least an oligo A dispersion obtained by melt-kneading an incompatible auxiliary agent containing sugar, a thermoplastic resin composition containing at least a first thermoplastic resin and inorganic particles composed of at least a cyclic polyolefin polymer, and at least (meta ) Melting and kneading a thermoplastic resin composition containing a second thermoplastic resin composed of an acrylic polymer and inorganic particles and an incompatible auxiliary agent containing at least a water-soluble polysaccharide having a cyclic structure The resulting dispersion.

  The composite resin particles are included in the dispersion as a dispersed phase, and are obtained by eluting the auxiliary from the dispersion.

  In this specification, terms such as “polymer”, “hydrophobic polymer”, “hydrophilic polymer”, “water-soluble polymer”, “plastic”, and “thermoplastic resin” are referred to as “new edition polymer dictionary” (published by Asakura Shoten). Reference can be made to the definition of the Society of Polymer Science, November 25, 19998 (first edition). However, when the term “polymer” is used for the particles, it is synonymous with the term “plastic” in the above-mentioned “New Edition Polymer Dictionary”. , Added with additives such as plasticizers, stabilizers and pigments). Further, when the term “resin” is used as a constituent of the particle, such as “resin particle”, it may be synonymous with “plastic” defined in the above-mentioned “New Edition Polymer Dictionary”. In addition, when 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) The meaning is the same as “used to specify some polymers that are base materials for plastics”.

  In the present invention, composite resin particles (composite thermoplastic resin particles) having a core-shell structure in which inorganic particles (metal oxide or the like) are unevenly distributed in the shell can be obtained. In particular, in the composite resin particles of the present invention, the core can be composed of a cyclic polyolefin polymer, so that it has excellent performance such as high light transmittance or low water absorption, and has an affinity with organic solvents and various binders. Composite resin particles having high dispersibility in an organic solvent and good affinity with various binders can be obtained. Such composite resin particles can efficiently impart the function of inorganic particles to the composite resin particles. In particular, when the thickness of the shell is small, the transparency of the composite resin particles can be maintained. Further, when the dispersibility of the inorganic particles in the shell is increased and the dispersion of the inorganic particles is improved to a level at which the shell becomes transparent, the refractive index difference between the core and the shell increases, and a unique scattering characteristic can be imparted.

  The composite resin particle of the present invention includes a core composed of a first thermoplastic resin and a shell composed of a second thermoplastic resin different from the first thermoplastic resin and covering the core. Composite resin particles having a core-shell structure. Such a composite resin particle is usually a composite resin particle in which inorganic particles are usually unevenly distributed in a specific part, that is, the shell (specifically, the inorganic particles are included in the entire core). Composite resin particles).

  As described later, such composite resin particles can usually be obtained by eluting the auxiliary from a dispersion in which the composite resin particles are dispersed in a specific auxiliary.

[First thermoplastic resin]
The first thermoplastic resin constituting the core is not particularly limited as long as it is a thermoplastic resin capable of forming a core-shell structure according to the type of the second thermoplastic resin. For example, a polyester polymer (or polyester) In the following, the term “polymer” may be used for consent to a polymer or polyester resin, for example, an aromatic polyester polymer or an aliphatic polyester polymer), a polyamide polymer, a polyurethane polymer high Molecule, poly (thio) ether polymer [for example, polyacetal polymer, polyphenylene ether polymer, polysulfide polymer, poly (thio) etherketone polymer (polyetherketone, polyetheretherketone, polyphenylene sulfide) Ketone, etc.)], polycarbonate polymer, polysulfur Condensation-type thermoplastic resins such as polyimide polymers, polyimide polymers (eg, polyimide, polyetherimide, polyamideimide, etc.); polyolefin polymers, (meth) acrylic polymers, styrenic polymers, vinyl-based polymers Polymers such as vinyl acetate-based polymers, polyvinyl alcohol-based polymers, halogen-containing vinyl-based polymers, vinyl ester-based polymers or their derivatives, etc .; vinyl-polymerized thermoplastic resins; derived from natural products such as cellulose derivatives Polymer; Thermoplastic silicone polymer; Thermoplastic elastomer and the like. These resins can be used alone or in combination of two or more.

  Preferred first thermoplastic resins include hydrophobic polymers such as polyolefin polymers, styrene polymers, hydrophobic vinyl polymers (vinyl chloride polymers, fluoropolymers, etc.), thermoplastic elastomers ( Olefin elastomer, styrene elastomer, etc.). The hydrophobic thermoplastic resin may be a nonpolar resin (or no polar group). Further, the hydrophobic polymer may be an amorphous polymer. An amorphous polymer is a polymer that is also called an amorphous polymer and does not show a clear crystal state, and is often found in atactic polymers and copolymer polymers. The amorphous polymer referred to in the present invention is an amorphous polymer in a broad sense that does not exhibit clear crystallinity, and includes a polymer having a slight crystal structure (for example, a crystallinity of 5% or less). Polymer) is also included in the category of amorphous polymers. Further, depending on the type of the second thermoplastic resin, a thermoplastic resin having a polar group (for example, (meth) acrylic polymer (such as a polymer described later), polyamide polymer (such as a polymer described later), etc. ) Can also be used as the first thermoplastic resin.

  Particularly preferred first thermoplastic resins include polyolefin polymers and styrene polymers. Hereinafter, these preferable thermoplastic resins will be described in detail.

(Polyolefin polymer)
Examples of the polyolefin-based polymer include α-C _2-6 olefin homo- or copolymers (eg, polyethylene, polypropylene, ethylene-propylene copolymer, poly (methylpentene-1), etc.), α-C _{2. -6} Copolymer of olefin and copolymerizable monomer (for example, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, etc.) And cyclic polyolefin polymers. These polyolefin polymers can be used alone or in combination of two or more.

  In particular, in the present invention, an olefin polymer having a relatively high melt viscosity such as a cyclic polyolefin polymer (cycloolefin polymer) can be suitably used.

  Cyclic polyolefin polymer is a generic term for polymers composed of a polymerizable cyclic olefin (cycloolefin) having an ethylenic double bond in the ring as a monomer unit, and a cyclic olefin homopolymer or copolymer [cyclic olefin A single ring-opening polymer, a ring-opening polymer of two or more kinds of cyclic olefins (such as a copolymer of a monocyclic olefin and a polycyclic olefin such as norbornene), a cyclic olefin and a copolymerizable monomer In addition to a copolymer with a body, a polymer blend or a polymer alloy (a polymer blend of the above polymer with various rubber-like polymers, amide polymers, ester polymers, elastic elastomers, etc.) is exemplified. Such polymers or polymers are disclosed in, for example, JP-A-60-168708, JP-A-612020816, JP-A-62-252406, JP-A-2-167318, It is disclosed in Japanese Laid-Open Patent Publication No. 4-35653.

  Typical cyclic olefins include, for example, norbornenes (for example, 2-norbornene, 5-methyl-2-norbornene, 5,5 or 5,6-dimethyl-2-norbornene, 5-ethylidene-2-norbornene, 5 -Cyano-2-norbornene, 5-methoxycarbonyl-2-norbornene, 5-phenyl-2-norbornene, 5-methyl-5-methoxycarbonyl-2-norbornene, 5,6-dimethoxycarbonyl-2-norbornene, 5, 6-di (trifluoromethyl) -2-norbornene, 7-oxo-2-norbornene, etc.), cyclopentadiene or dicyclopentadiene, 1,4,5,8 obtained by condensation of norbornene with cyclopentadiene Dimethano-1,2,3,4,4a, 5,8,8a-octahydrona Talens, hexacyclo [6.6.1.1.1.1.0] heptadecene-4s, 6-ethylbicyclo [2.2.1] hept-2-ene synthesized from ethylene and cyclopentadiene, etc. Can be illustrated. A cyclic olefin can be used individually or in combination of 2 or more types. In particular, the cyclic olefin may be norbornenes (for example, alkylnorbornene such as 2-norbornene and 5-methyl-2-norbornene).

The copolymerizable monomer is not particularly limited as long as it can be copolymerized, 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 C ₂ such as -pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene _-20 alkene), alkadienes (eg, 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene) Non-conjugated C _5-20 alkadiene, etc.]. These copolymerizable monomers can be used alone or in combination of two or more. Copolymerizable monomers include α-olefins (for example, C _2-10 α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, in particular C _2-6 α-olefins. ).

  Furthermore, within a range not impairing the effects of the present invention, as a copolymerizable monomer, a polymerizable nitrile compound (for example, (meth) acrylonitrile), a (meth) acrylic monomer (for example, (meth) acrylic) (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.

Preferred cyclic polyolefin polymers are copolymers of chain olefins (α-olefins such as ethylene) and cyclic olefins (particularly norbornenes) (for example, α-C ₂₋ such as ethylene-cyclic olefin copolymers). _A copolymer of _4- olefin and cyclic olefin). Such a copolymer combines the properties of an olefin polymer (such as an ethylene polymer) and a cyclic olefin polymer. By adjusting the α-olefin copolymerization ratio, a desired glass transition temperature is obtained. And a high molecular weight polymer can be obtained. From the viewpoint of heat resistance, a cyclic polyolefin polymer obtained by condensing norbornene and cyclopentadiene (or dicyclopentadiene), norbornene and cyclopentadiene (or dicyclopentadiene), and a copolymerizable monomer ( For example, a cyclic polyolefin copolymer obtained by polymerizing α-olefins) is preferable. In addition, the usage-amount in particular of a copolymerizable monomer (for example, alpha olefins) in a cyclic polyolefin type copolymer is not restrict | limited, A small amount (for example, about 1-25 mol%, Preferably about 2-20 mol%) ).

  Cyclic polyolefin polymers may be used alone or in combination of two or more.

  In addition, the cyclic polyolefin polymer (for example, a copolymer of α-olefin and cyclic olefin) has a high glass transition temperature and is prone to breakage. It is difficult to form such a cyclic polyolefin polymer into particles by a conventional method. However, even with such a cyclic polyolefin polymer, resin particles can be obtained by making particles by the method of the present invention.

  The glass transition temperature can be used as an index of the plasticizing temperature of the cyclic polyolefin polymer, and the glass transition temperature of the cyclic polyolefin polymer can be selected according to desired characteristics, such as heat resistance. It is about 80 to 175 ° C. (for example, 85 to 165 ° C.), more preferably about 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 the auxiliary agent described later is expanded, but the heat resistance of the resin particles is reduced. In the present invention, particularly by using a water-soluble polysaccharide having at least one cyclic structure as an auxiliary agent, even if it is a cyclic polyolefin polymer having a high glass transition temperature, composite resin particles (for example, Spherical composite resin particles) can be obtained efficiently. Therefore, the glass transition temperature of the cyclic polyolefin polymer 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 polymer is a weight average molecular weight (Mw) of 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 × 10 ⁴ to 18 × 10 ⁴ ), more preferably about 7 × 10 ⁴ to 15 × 10 ⁴ (8 × 10 ^{4 to} 12 × 10 ⁴ ). It is not preferable to form a cyclic polyolefin polymer having a weight average molecular weight of 2 × 10 ⁴ or less by a pulverization method because the molecular weight is further reduced, and a cyclic polyolefin polymer exceeding 2 × 10 ⁴ is physically pulverized. It is difficult to do. On the other hand, in the present invention, even a cyclic polyolefin polymer having such a molecular weight can be formed into particles while preventing a decrease in molecular weight.

(Styrene polymer)
As the styrene polymer, a styrene monomer (styrene, α-methylstyrene, vinyltoluene, etc.) or a copolymer (polystyrene, styrene-vinyltoluene copolymer, styrene-α-methylstyrene copolymer) ), A copolymer of a styrene monomer and a copolymerizable monomer (styrene-acrylonitrile copolymer (AS resin), (meth) acrylic acid ester-styrene copolymer (MS resin, etc.), styrene -Copolymers such as maleic anhydride copolymer, styrene-butadiene block copolymer, etc .; acrylonitrile-acrylic ester-styrene copolymer (AAS resin), acrylonitrile-chlorinated polyethylene-styrene copolymer (ACS resin) ), Styrene series such as acrylonitrile-vinyl acetate-styrene copolymer (AXS resin) Graft copolymer: Graft polymer obtained by graft polymerization of at least a styrene monomer in the presence of a rubber component, such as impact-resistant polystyrene (HIPS or rubber-grafted polystyrene resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-ethylenepropylene rubber-styrene copolymer (AES resin) and the like. These styrenic polymers can be used alone or in combination of two or more.

[Second thermoplastic resin]
The second thermoplastic resin is a thermoplastic resin different from the first thermoplastic resin, and is not particularly limited as long as a core-shell structure can be formed in combination with the first thermoplastic resin. From the conventional thermoplastic resin It can be selected as appropriate.

The second thermoplastic resin may usually be a thermoplastic resin having a polar group (or a hydrophilic group). As the polar group, a hydroxyl group, a carboxyl group, an amino group, an imino group (—NH—), an ether group, an oxyalkylene group (polyoxy C _2-4 linear or branched such as a polyoxyethylene group and a polyoxypropylene group) An alkylene group), an ester group (or ester bond), an amide group (or amide bond), a urethane bond (—NHC (═O) O—) and the like. The 2nd thermoplastic resin may have the said polar group individually or in combination of 2 or more types.

A typical second thermoplastic resin is, among the exemplified resins, a polyester polymer, a polyamide polymer, a polycarbonate polymer, a polyurethane polymer, a vinyl acetate polymer, a polyvinyl alcohol polymer, (Meth) acrylic polymer [(meth) acrylic polymer having (meth) acrylic acid or (meth) acrylic acid alkyl ester as a constituent unit]], cellulose derivative, thermoplastic elastomer (poly C _2-4 oxy) And hydrophilic polymers such as polyamide elastomers, polyester elastomers, polyurethane elastomers having an alkylene unit as a soft segment. These thermoplastic resins can be used alone or in combination of two or more.

  Preferred second thermoplastic resins include (meth) acrylic polymers, polyamide polymers, vinyl alcohol polymers (such as ethylene-vinyl alcohol polymers), and particularly (meth) acrylic resins. Polymers and polyamide polymers are preferred. Hereinafter, these preferable polymers will be described in detail.

((Meth) acrylic polymer)
Examples of the (meth) acrylic polymer include (meth) acrylic monomers ((meth) acrylic acid, (meth) acrylic acid C _1-18 alkyl ester, (meth) acrylic acid hydroxyalkyl, (meth) Glycidyl acrylate, (meth) acrylonitrile, etc.) or a copolymer, for example, poly (meth) acrylate such as methyl poly (meth) acrylate, methyl methacrylate- (meth) acrylic acid copolymer, methacryl Acid methyl-acrylic acid ester- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, (meth) acrylic acid ester-styrene copolymer (MS resin, etc.) and the like. . Preferred (meth) acrylic polymers include poly (meth) acrylic acid C _1-5 alkyl, methyl methacrylate-acrylic acid ester copolymer, (meth) acrylic acid ester-styrene copolymer (MS resin, etc.). Etc. are included. These (meth) acrylic polymers can be used alone or in combination of two or more.

(Vinyl alcohol polymer)
Examples of vinyl alcohol polymers (or vinyl alcohol polymers) include olefins such as polyvinyl alcohol, fatty acid vinyl esters and copolymerizable monomers [C _2-4 olefins (ethylene, propylene, butene, etc.); Saponified products of copolymers with (meth) acrylic monomers such as (meth) acrylic acid and (meth) acrylic acid esters; alkyl vinyl ethers; vinyl pyrrolidone, etc. (for example, ethylene-vinyl alcohol copolymers) Etc. are included. In the ethylene-vinyl alcohol copolymer, the ethylene content may be 1 to 30% by weight, preferably 2 to 20% by weight, and more preferably about 2 to 10% by weight. The saponification degree of the vinyl alcohol polymer is, for example, 70 mol% or more, preferably 80 mol% or more, and more preferably 90 mol% or more.

(Polyamide polymer)
Examples of the polyamide polymer include an aliphatic polyamide polymer, an alicyclic polyamide polymer, an aromatic polyamide polymer, and the like. Usually, an aliphatic polyamide polymer is used. These polyamide polymers can be used alone or in combination of two or more.

Examples of the aliphatic polyamide polymer include an aliphatic diamine component (C _4-10 alkylene diamine such as tetramethylene diamine and hexamethylene diamine) and an aliphatic dicarboxylic acid component (C ₄ such as adipic acid, sebacic acid and dodecanedioic acid). C- ₂₀ such as polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, polyamide 1212), lactam (ε-caprolactam, ω-laurolactam, etc.) _4-20 lactam or the like) or aminocarboxylic acid (carbon number C such as ω-aminoundecanoic acid C _4-20 aminocarboxylic acid etc.) or a copolymer (for example, polyamide 6, polyamide 11, polyamide 12 etc.), these Of polyamide component Examples thereof include copolymerized copolyamides (for example, polyamide 6/11, polyamide 6/12, polyamide 66/11, polyamide 66/12, etc.).

Further, the polyamide polymer may have biodegradability. Examples of the biodegradable polyamide polymer include the aliphatic diamine component (C _4-10 alkylenediamine such as tetramethylenediamine and hexamethylenediamine) and the aliphatic dicarboxylic acid component (adipic acid, sebacic acid, dodecanedioic acid, etc.) C _4-20, such as alkylene dicarboxylic acids) of the aliphatic diol component (ethylene glycol, propylene glycol, C _2-12 polyesteramides which is a condensation product of an alkylene glycol, etc.), such as butanediol.

  Note that the second thermoplastic resin may be composed of a plurality of thermoplastic resins. When the second thermoplastic resin is composed of a plurality of thermoplastic resins, one thermoplastic resin (for example, (meth) acrylic resin) and the other thermoplastic resin (for example, two types of thermoplastic resins). In the case of a resin, the ratio to the other thermoplastic resin) is the former / the latter (weight ratio) = 99/1 to 10/90, preferably 95/5 to 20/80, more preferably 90/10. It may be about 25/75 (for example, 80/20 to 30/70).

  As a typical combination of the first thermoplastic resin and the second thermoplastic resin (a combination capable of forming a core-shell structure), (1) a cyclic polyolefin polymer (first thermoplastic resin) and a polar group are used. A combination with a thermoplastic resin (second thermoplastic resin, in particular, a (meth) acrylic polymer and / or a vinyl alcohol polymer), and (2) a styrene polymer (first thermoplastic resin) Combination with a thermoplastic resin having a polar group (second thermoplastic resin, in particular, polyamide polymer), (3) (meth) acrylic polymer (first thermoplastic resin) and heat having a polar group A combination with a plastic resin (second thermoplastic resin) (specifically, a thermoplastic resin having a polar group different from the (meth) acrylic polymer, such as a vinyl alcohol polymer), ( ) Polyamide polymer (thermoplastic resin having a first thermoplastic resin) and polar group (second thermoplastic resin, for example, a combination of vinyl alcohol-based polymer, etc.). JP, 2005-162797, A can also be referred to as a combination of the 1st thermoplastic resin and the 2nd thermoplastic resin.

  Among these combinations, the combination (1) is particularly preferable, and among the combinations (1), at least the first thermoplastic resin composed of at least a cyclic polyolefin polymer and at least a (meth) acrylic polymer. Constructed second thermoplastic resin [for example, (meth) acrylic polymer, (meth) acrylic polymer and thermoplastic polymer having a polar group (specifically, (meth) acrylic polymer A combination with a thermoplastic resin having a different polar group, a vinyl alcohol polymer, or the like) is preferred.

[Inorganic particles]
Inorganic particles (inorganic particles or fillers or fillers) may be meltable together with the first thermoplastic resin and the second thermoplastic resin during the preparation of the dispersion described below, but usually these heats In many cases, it does not melt at the kneading temperature of the plastic resin. The inorganic particles can be used alone or in combination of two or more.

  Examples of the inorganic particles (inorganic filler) include silica such as metal oxide (fine powder silica (anhydride), white carbon (hydrate)), alumina, titania, zirconia, titanium oxide, iron oxide, strontium oxide, and oxidation. Cerium, zinc oxide, etc.), metal hydroxides (such as aluminum hydroxide), metal salts (sulfates, carbonates such as calcium carbonate; phosphates such as calcium phosphate and titanium phosphate; mica, calcium silicate, bentonite, zeolite Silicates such as barleystone, talc and montmorillonite; tungstates such as calcium tungstate; titanates such as barium titanate, potassium titanate and aluminum titanate), metal nitride (silicon nitride, boron nitride) , Aluminum nitride, titanium nitride, etc.), metal carbide (silicon carbide) , Boron carbide, titanium carbide, tungsten carbide, etc.), metal borides (titanium boride, zirconium boride, etc.), metals (gold, platinum, palladium, etc.), carbon (carbon black, graphite, fullerene, carbon nanotubes, etc.), etc. Can be illustrated. The inorganic particles may be in the form of powder or may be in the form of fibers (for example, glass fibers, carbon fibers, metal fibers, whiskers, etc.). Inorganic particles are ferromagnetic materials such as ferromagnetic metals (powder) such as iron, cobalt, nickel; ferromagnetic alloys (powder) such as magnetite and ferrite; ferromagnetic metal oxides (powder) such as magnetic iron oxide, etc. It may be. These inorganic particles can be used alone or in combination of two or more.

  The inorganic particles also include a colorant such as a pigment [inorganic colorant (inorganic pigment)]. The colorant may be achromatic or chromatic (yellow, orange, red, purple, blue, green, etc.).

  Inorganic colorants (inorganic pigments) include extender pigments (calcium carbonate, barium sulfate, silica, aluminum hydroxide, kaolin clay, talc, bentonite, etc.), white pigments (titanium oxide, zinc oxide, etc.), yellow pigments (resurge, Yellow lead, yellow iron oxide, cadmium yellow, etc.), red pigment (bengara etc. iron oxide, lead red, molybdenum red, cadmium red etc.), blue pigment (bituminous, ultramarine blue, etc.), black pigment (carbon black etc.), etc. Can be mentioned. The colorant may be a fluorescent pigment or a phosphorescent pigment. The colorants can be used alone or in combination of two or more.

  The inorganic particles may have various functions such as ultraviolet absorption (or blocking property). Typical inorganic particles include metal oxides (or metal oxide particles) such as titanium oxide and zinc oxide.

The inorganic particles may be surface treated. Examples of the surface treatment include a hydrophobic treatment. Surface treatment (particularly hydrophobization treatment) can be performed by treating (or coating treatment) inorganic particles with a surface treatment agent. In the inorganic particles treated with such a surface treating agent, as the surface treating agent, a surface treating agent capable of hydrophobizing the inorganic particles, for example, silica [tetraalkoxysilanes (tetra C _1-4 such as tetramethoxysilane) is used. A surface treatment by a sol-gel method using an alkoxysilane or an oligomer thereof)], a coupling agent (such as a titanium coupling agent or a silane coupling agent), or a polyorganosiloxane. These surface treatment agents may be used alone or in combination of two or more.

  Examples of the silane coupling agent include a halogen-containing silane coupling agent (such as 3-chloropropyltrimethoxysilane), an epoxy group-containing silane coupling agent (such as 3-glycidyloxypropyltrimethoxysilane), and an amino group-containing silane cup. Ring agent (such as 2-aminoethyltrimethoxysilane), mercapto group-containing silane coupling agent (such as 3-mercaptopropyltrimethoxysilane), vinyl group-containing silane coupling agent (such as vinyltrimethoxysilane), (meth) acryloyl Group-containing silane coupling agents (such as 2- (meth) acryloxyethyltrimethoxysilane) are included.

The polyorganosiloxane, for example, polydialkylsiloxane (e.g., polydiene C _1-10 alkyl siloxanes such as polydimethylsiloxane (dimethicone), preferably polydiene C _1-4 alkyl), poly alkyl alkenyl siloxane (e.g., polymethyl Poly C _1-10 alkyl C _2-10 alkenyl siloxanes such as vinyl siloxane), polyalkyl aryl siloxanes (eg poly C _1-10 alkyl C _6-20 aryl siloxanes such as polymethylphenyl siloxane, preferably poly C _{1 1- 4} alkyl _{C 6-10} aryl siloxanes), polydiene aryl siloxanes (e.g., polydiene _{C 6-20} aryl siloxanes such as poly diphenyl siloxane), poly alkyl hydrogen siloxane (eg , Poly C _1-10 alkyl siloxane, such as polymethyl hydrogen siloxane), polyorganosiloxane copolymer (e.g., dimethylsiloxane - methylvinylsiloxane copolymer, dimethylsiloxane - methylphenylsiloxane copolymer, dimethylsiloxane - Methylvinylsiloxane-methylphenylsiloxane copolymer, dimethylsiloxane-methylhydrogensiloxane copolymer (dimethicone / methicone copolymer, etc.), modified polyorganosiloxane [modified polyorganosiloxane corresponding to the polyorganosiloxane, eg hydroxyl Modified polyorganosiloxane (eg, terminal silanol polydimethylsiloxane, terminal silanol polymethylphenylsiloxane, terminal hydroxypropyl) Redimethylsiloxane, polydimethylhydroxyalkylene oxide methylsiloxane, etc.), amino-modified polyorganosiloxane (eg, terminal dimethylaminopolydimethylsiloxane, terminal aminopropylpolydimethylsiloxane), carboxy-modified polyorganosiloxane (eg, terminal carboxypropylpolysiloxane) Dimethyl siloxane etc.)] and the like.

  Among these, particularly preferred polyorganosiloxanes include polyorganosiloxanes (eg, polydimethylsiloxane (or dimethicone), dimethicone / methicone copolymer) containing at least polydimethylsiloxane (dimethicone) units or polymethylhydrogensiloxane (methicone) units. , Mixtures thereof, etc.).

  The viscosity of the polyorganosiloxane is, for example, about 0.5 to 100000 cSt (centistokes), preferably 1 to 50000 cSt, more preferably 5 to 20000 cSt, particularly 10 to 10000 cSt (for example, 10 to 5000 cSt) at 25 ° C. May be.

  These surface treatment agents (such as polyorganosiloxane) may be used alone or in combination of two or more.

  Preferred surface treatment agents include silicon-based surface treatment agents (silica, polyorganosiloxane, etc.).

  In addition, even if the ratio of a surface treating agent is 1 to 70 weight% with respect to the whole inorganic particle (surface-treated inorganic particle), Preferably it is 2 to 50 weight%, More preferably, it is about 3 to 30 weight%. Good.

  The average particle diameter (primary particle diameter) of the inorganic particles can be selected according to the size of the resin particles, and can be selected from a wide range of, for example, an average particle diameter of about 1 nm to 10 μm, usually 2 nm to 1 μm, preferably 3 to 500 nm. More preferably, it may be about 5 to 300 nm. The average particle size of the preferred inorganic particles is 150 nm or less (for example, 2 to 120 nm), preferably 100 nm or less (for example, 3 to 100 nm), more preferably 80 nm or less (for example, 5 to 75 nm), particularly 50 nm or less (for example, 10 to 40 nm).

  In addition, you may use an inorganic particle in the form of the masterbatch previously diluted with resin or a pre-mixture. The masterbatch can be produced by mixing the resin and inorganic particles using a conventional kneader. As will be described later, the resin may be the first thermoplastic resin and / or the second thermoplastic resin, or may be a resin different from these. The concentration of the inorganic particles in the master batch is not particularly limited, and may be a conventional concentration, for example, about 5 to 70% by weight.

[Composite resin particles]
As described above, the composite resin particles of the present invention are composed of the core composed of the first thermoplastic resin, the shell composed of the second thermoplastic resin, and the inorganic particles. The inorganic particles are unevenly distributed in the shell and are contained in the composite resin particles. The composite resin particles in which the inorganic particles are unevenly distributed in such a specific portion are a combination of the first thermoplastic resin and the second thermoplastic resin (moreover, the first or second thermoplastic resin and the inorganic fine particles are combined. The combination can be selected, or the type of matrix (auxiliary) constituting the dispersion can be selected as described later.

  Hereinafter, representative composite resin particles of the present invention will be exemplified.

  Composite resin particles in which the first thermoplastic resin is composed of at least a cyclic polyolefin polymer, and the second thermoplastic resin is composed of at least a (meth) acrylic polymer.

  In the composite resin particles, the inorganic particles may be nanoparticles [or nano-sized particles, for example, inorganic particles having an average primary particle diameter of 50 nm or less (particularly metal oxide particles)]. The inorganic particles may be inorganic particles that have been surface-treated (or hydrophobized).

  In the composite resin particles, the ratio of the first thermoplastic resin (or core) to the second thermoplastic resin (or shell) is the former / the latter (weight ratio) = 30/70 to 99/1, preferably 40 / 60 to 95/5, more preferably about 50/50 to 90/10, usually 50/50 to 99/1 (for example, 55/45 to 95/5, preferably 60/40 to 85). / 15) degree may be sufficient.

  The proportion of the inorganic particles may be, for example, about 0.1 to 40% by weight, preferably 0.5 to 30% by weight, and more preferably about 1 to 20% by weight with respect to the entire composite resin particle.

  In the composite resin particles, the proportion of the inorganic particles is 1 to 60 parts by weight, preferably 3 to 50 parts by weight, more preferably 5 to 5 parts by weight with respect to 100 parts by weight of the second thermoplastic resin (or shell). It may be about 40 parts by weight, particularly about 10 to 35 parts by weight (for example, 15 to 30 parts by weight).

  The core-shell structure in the composite resin particle may be a structure in which at least a part or the whole of the core (or the surface of the core) is covered by the shell, and is usually a structure in which the entire core (or the surface of the core) is covered by the shell. It may be. The core may be a single core or a plurality of cores as long as the core is covered with a shell.

  In the case of being composed of a plurality of cores, the number (average number) of cores contained in one shell may be, for example, 2 to 20, preferably 3 to 15, more preferably about 4 to 10. .

  The shape of the composite resin particles may be in the form of particles, and may be, for example, spherical (or true spherical), irregular shape (ellipsoidal shape, columnar shape, rod shape, indefinite shape, etc.), and the like. A preferred shape is spherical. In the case of composite resin particles in which a plurality of cores are included in the shell, the shape of the core may be spherical, but may be irregular (elliptical, polygonal, prismatic, cylindrical, rod, indeterminate) , Dumbbells, etc.). In general, in the case of composite resin particles in which a plurality of cores are included in the shell, the shape of the core may be non-spherical (such as an ellipsoid), and in particular, surfaces that are not adjacent to each other in one shell (shell) In many cases, the side surface and the like have a curved surface shape, and the surface adjacent to the core adjacent to each other (adjacent part) in one shell has a shape obtained by deforming the curved surface shape. In the case of composite resin particles in which a plurality of cores are included in the shell, each core included in the shell is separated from other cores included in the same shell in part or all (part or all of the surface) (or It may be included in the shell after being separated, and may be in contact with (or in close contact with) the other core.

  Moreover, the surface of the composite resin particle may have an uneven shape or a curved shape. In particular, when the composite resin particle of the present invention is a composite resin particle in which a shell includes a plurality of cores, the shape of the shell (or the outer surface shape of the composite resin particle) may be spherical, but is usually irregular. (Ellipsoidal shape, rod shape, indefinite shape, etc.). In the case of composite resin particles in which a shell includes a plurality of cores, the outer shape (or outer surface) of the shell (or composite resin particles) is often uneven. In general, the shape of the core-shell type resin particles is spherical or true spherical. The concavo-convex concave and convex portions may be square, but are often curved. The outer shape of the composite resin particle including a plurality of cores in the shell may typically be a shape in which a plurality of curved portions are connected (or a shape having a plurality of curved surfaces), and in particular, a so-called potato shape. (Or potato-like).

  The average particle diameter (volume average particle diameter Dw) of the composite resin particles of the present invention can be selected from a range of about 0.01 to 100 μm (for example, 0.05 to 80 μm), for example, depending on the application. About 60 micrometers (for example, 0.1-30 micrometers) may be sufficient. The average particle diameter (volume average particle diameter Dw) of the composite resin particles is usually about 1 to 80 μm (for example, 3 to 75 μm), depending on the application, 20 to 70 μm, preferably 30 to 60 μm (for example, 30 to 50 μm). ) Degree may be appropriate. For example, the average particle diameter of the composite resin particles is usually 1 to 50 μm, preferably 5 to 40 μm, and more preferably about 10 to 30 μm in coloring applications with cosmetics and cosmetic applications.

  In the composite resin particles of the present invention, the ratio Dw / Dn of the volume average particle diameter Dw [μm] to the number average particle diameter Dn [μm] is 1 to 6, preferably 1.05 to 5, more preferably 1.1. It may be about ~ 4.5. Furthermore, the CV value (coefficient of variation) of the particle diameter calculated by the following formula is usually 5 to 99%, preferably 20 to 98%, and more preferably about 30 to 97%.

CV value of particle diameter (%) = (standard deviation of number average particle diameter / number average particle diameter) × 100
The composite resin particles of the present invention are not particularly limited, but usually from a dispersion in which the composite resin particles are dispersed in an auxiliary agent incompatible with the first thermoplastic resin and the second thermoplastic resin. And obtained by eluting the incompatible auxiliary agent. Therefore, such a dispersion is also included in the present invention. Hereinafter, the dispersion (dispersion having a composite resin particle as a dispersed phase) will be described in detail.

[Dispersion]
As described above, the dispersion includes an auxiliary agent incompatible with the first thermoplastic resin and the second thermoplastic resin, and the composite resin particles dispersed in the auxiliary agent (inorganic particles are unevenly distributed). Composite resin particles). That is, the dispersion is composed of the composite resin particles as a dispersed phase (or dispersed phase particles) and the auxiliary agent as a continuous phase (or matrix).

(Auxiliary)
The auxiliary agent is usually a thermoplastic that can be melted at the plasticizing temperature of the first thermoplastic resin and the second thermoplastic resin, and is non-insensitive to the first thermoplastic resin and the second thermoplastic resin. Any auxiliary agent that is compatible and can be dissolved in a solvent that does not dissolve the first thermoplastic resin and the second thermoplastic resin may be used. For example, non-hydrophilic organic solid compounds such as aliphatic polyesters can be used as long as they satisfy such conditions.

  The auxiliary agent is preferably a hydrophilic organic component (such as a hydrophilic resin or a hydrophilic organic solid compound), particularly a water-soluble organic component. If a water-soluble thermoplastic component is selected as an auxiliary agent, the incompatibility requirement between the dispersed phase and the continuous phase can be easily satisfied. Examples of such auxiliaries include water-soluble polymers that can be melt-molded and polysaccharides. The water-soluble polymer is not particularly limited as long as it is a water-soluble resin that can be melt-molded, and examples thereof include polyvinyl alcohol polymers, polyethylene glycol, and polyethylene oxide. A preferable water-soluble polymer is a polyvinyl alcohol polymer [particularly, an oxyalkylene group-containing polyvinyl alcohol polymer such as a saponification product of a copolymer of an ethylenically unsaturated monomer containing an oxyalkylene group and vinyl acetate]. Preferably used.

  The auxiliaries may consist in particular of polysaccharides such as caramel, modified starch, etherified cellulose, etheresterified cellulose, esterified cellulose. The auxiliary agent is particularly at least one selected from water-soluble polysaccharides, particularly oligosaccharides and water-soluble polysaccharides having at least one cyclic structure (sometimes referred to as polysaccharides having a cyclic structure, cyclic polysaccharides and the like). It is preferably composed of a water-soluble polysaccharide, and both may be used in combination. By properly using an oligosaccharide and / or a polysaccharide having a cyclic structure (further, a water-soluble plasticizing component described later), the melt viscosity can be adjusted, and the portion (that is, the shell) where the inorganic particles are unevenly distributed in the composite resin particles, Can efficiently control the particle diameter and the like of the composite resin particles. When such a water-soluble polysaccharide is used, when the dispersion is eluted or washed to obtain composite resin particles, the solution viscosity of the auxiliary agent dissolved in the solvent is not increased, and the composite resin particles are easily obtained. be able to.

(oligosaccharide)
Oligosaccharides are roughly classified into homo-oligosaccharides and hetero-oligosaccharides, and these oligosaccharides may be anhydrides. In the oligosaccharide, a monosaccharide and a sugar alcohol may be bonded. The oligosaccharide may be an oligosaccharide composition composed of a plurality of sugar components. Even such an oligosaccharide composition may be simply referred to as an oligosaccharide. Oligosaccharides (or oligosaccharide compositions) can be used alone or in combination of two or more. Oligosaccharides include disaccharides to decasaccharides.

  Examples of the disaccharide include homo-oligosaccharides such as trehalose, maltose, isomaltose, and cellobiose; and hetero-oligosaccharides such as lactose, sucrose, and palatinose.

  Trisaccharides include homo-oligosaccharides such as maltotriose, isomaltotriose, panose and cellotriose; hetero-oligosaccharides such as manninotriose, solatriose, melezitose, planteose, gentianose, umbelliferose, lactosucrose and raffinose It is done.

  Examples of tetrasaccharides include homo-oligosaccharides such as maltotetraose and isomalttetraose; and hetero-oligosaccharides such as tetraose in which sugar or sugar alcohol is bonded to the reducing end of stachyose, cellotetraose, scorodose, liquinose, or panose.

  Among these tetrasaccharides, tetraose in which a monosaccharide or a sugar alcohol is bonded to the reducing end of panose is disclosed, for example, in JP-A-10-215892, and glucose, fructose, mannose, Examples include tetraose to which monosaccharides such as xylose and arabinose and sugar alcohols such as sorbitol, xylitol and erythritol are bonded.

  Examples of the pentasaccharide include homooligosaccharides such as maltopentaose and isomaltopentaose; and heterooligosaccharides such as pentaose in which a disaccharide is bonded to the reducing end of panose. Pentaose in which a disaccharide is bonded to the reducing end of panose is disclosed, for example, in JP-A-10-215892, and pentaose in which a disaccharide such as sucrose, lactose, cellobiose or trehalose is bonded to the reducing end of panose. It can be illustrated.

  Examples of hexasaccharides include homo-oligosaccharides such as maltohexaose and isomalthexaose.

  The oligosaccharide may be an oligosaccharide composition produced by degradation of a polysaccharide. Examples of the oligosaccharide composition include starch sugar (starch saccharified product), galacto-oligosaccharide, coupling sugar, fructooligosaccharide, xylo-oligosaccharide, soybean oligosaccharide, chitin oligosaccharide, chitosan oligosaccharide and the like. It can be used alone or in combination of two or more. For example, the starch sugar may be a mixture of oligosaccharides having a plurality of glucose bound thereto. Further, such an oligosaccharide composition (oligosaccharide mixture) may be bonded to a sugar alcohol in the same manner as described above. That is, the oligosaccharide composition (or the oligosaccharide constituting the oligosaccharide composition) may have an oligosaccharide unit and a sugar alcohol unit bonded to the oligosaccharide unit. Such sugar alcohol units are usually often located at the end of oligosaccharide units. That is, the oligosaccharide constituting the oligosaccharide composition may have a sugar alcohol unit whose terminal is reduced. In addition, the oligosaccharide composition having such a sugar alcohol unit can be obtained, for example, by reducing an oligosaccharide composition (such as starch sugar).

  Examples of starch sugar include reduced starch saccharified product (trade name: PO-10, tetrasaccharide content of 90% by weight or more) manufactured by Towa Kasei Kogyo Co., Ltd.

  In these oligosaccharide compositions, the content of trisaccharides and tetrasaccharides (particularly tetrasaccharides) in the oligosaccharide composition is, for example, 60% by weight or more (for example, about 60 to 100% by weight), preferably 70% by weight. % Or more (for example, about 70 to 100% by weight), more preferably 80% by weight or more (for example, about 80 to 100% by weight), particularly 90% by weight or more (for example, about 90 to 100% by weight). Good.

  In addition, the oligosaccharide composition may contain a large amount of relatively large multimeric oligosaccharides. For example, in the oligosaccharide composition, the content ratio of oligosaccharides of 20 or more saccharides is 20% by weight or more (for example, 25 to 100% by weight), preferably 30% by weight or more (eg 35 to 90% by weight), more preferably 40% by weight or more (eg 45 to 80% by weight), particularly about 50 to 70% by weight. Usually, it may be about 40 to 75% by weight.

  The oligosaccharide may be a non-reducing type (trehalose type), but a reducing type (maltose type) oligosaccharide is preferred because of its excellent heat resistance. The reduced oligosaccharide is not particularly limited as long as it is a sugar (such as a disaccharide, trisaccharide, tetrasaccharide, pentasaccharide, or hexasaccharide) that has a free aldehyde group or a ketone group and exhibits reducibility.

  The cyclic polyolefin polymer has a high melt viscosity even when it is plasticized at a temperature higher than the glass transition temperature, unlike when the crystalline polymer is heated to a temperature higher than the melting point. Therefore, in order to obtain resin particles having a desired particle size, it is necessary to increase the viscosity of the auxiliary agent or increase the kneading temperature. On the other hand, in the combination of an oligosaccharide and a water-soluble plasticizing component, if an oligosaccharide composed mainly of a disaccharide to a tetrasaccharide is used, the melt viscosity of the auxiliary agent at the kneading temperature decreases, and the cyclic polyolefin type high Depending on the type of molecule, resin particles having a desired particle size may not be obtained. Therefore, when a water-soluble auxiliary agent is composed of an oligosaccharide and a water-soluble plasticizing component, a pentasaccharide, a hexasaccharide, or an oligosaccharide having a number of sugars higher than that may be used.

  In order to effectively disperse the resin component 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 0.1 Pa · s or more (for example, about 0.2 to 2 Pa · s), Preferably 0.3 Pa · s or more (for example, 0.4 to 1.5 Pa · s, particularly about 0.45 to 1 Pa · s), more preferably 0.5 Pa · s or more (for example, 0.5 to 0. 0. 9 Pa · s).

  In addition, depending on the type of oligosaccharide (for example, starch sugar such as reduced starch saccharified product), it does not show a melting point or a softening point and may be decomposed (thermally decomposed). In such a case, the decomposition temperature may be the “melting point or softening point” of the oligosaccharide.

  The temperature difference between the melting point or softening point of the oligosaccharide and the thermal deformation temperature of the resin component (the first thermoplastic resin and the second thermoplastic resin) is, for example, 1 ° C. or more (for example, about 1 to 80 ° C.) The temperature is preferably 10 ° C. or higher (for example, about 10 to 70 ° C.), more preferably 15 ° C. or higher (for example, about 15 to 60 ° C.). The melting point or softening point of the oligosaccharide can be selected in the range of 70 to 300 ° C. depending on the type of the resin component, for example, 90 to 290 ° C., preferably 100 to 280 ° C. (for example, 110 to 270 ° C.), More preferably, it may be about 120 to 260 ° C (for example, 130 to 260 ° C).

(Water-soluble polysaccharide having a cyclic structure)
In order to increase the melt viscosity, the auxiliary agent (or water-soluble medium) may be composed of a water-soluble polysaccharide having at least one cyclic structure. In the water-soluble polysaccharide having a cyclic structure, the cyclic structure (cyclic skeleton, cyclic unit, cyclic portion) is composed of a plurality of glycose units [usually glucose units (particularly, D-glucose)] constituting a glucoside bond (or Any ring formed by glucosylation) may be used. 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.

  The average degree of polymerization of the glycolose units forming the cyclic structure may be 10 or more per one cyclic structure. In the water-soluble polysaccharide having the cyclic structure, the cyclic structure may be a cyclic structure (or a ring or a cyclic unit) including a 1,6-glucoside bond, for example, an α-1,4-glucoside bond. And a cyclic structure having an α-1,6-glucoside bond.

  Typically, the water-soluble polysaccharide having a cyclic structure has an α-1,4-glucoside bond and an α-1,6-glucoside bond, and the average degree of polymerization of the glycose unit per cyclic structure is 10 or more. And a non-cyclic structure bonded to the cyclic structure and an average polymerization degree (total average polymerization degree) of 50 or more.

  A water-soluble polysaccharide having a cyclic structure 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. By using such a specific polysaccharide, it is possible to maintain a higher shear viscosity in melt-kneading than oligosaccharides, etc., so that plasticity or melt viscosity is high and water-soluble, so it can be easily dissolved in water or the like. It can be removed.

  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, in the glucoside bond constituting the cyclic structure, the cyclic structure is usually a ring formed of at least 1,4-glucoside bond (particularly, α-1,4-glucoside bond). It may be a ring formed by a bond (particularly α-1,4-glucoside bond) and a 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 water-soluble polysaccharide which has a cyclic structure should just have at least 1 cyclic structure (cyclic unit), and may have a some cyclic structure.

  The average degree of polymerization of the water-soluble polysaccharide having a cyclic structure (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 It may be above (for example, 17 to 10000), more preferably 20 or more (for example, about 20 to 8000).

  The water-soluble polysaccharide having a cyclic structure may be derivatized (or modified). For example, a water-soluble polysaccharide having a cyclic structure has a hydroxyl group (alcoholic hydroxyl group) derivatized [for example, etherification (for example, alkyl etherification such as methyl etherification; hydroxyethyl etherification, hydroxypropyl etherification, etc. A hydroxyalkyl etherification; glycerylation, etc.), esterification, grafting, cross-linking, etc.].

  The water-soluble polysaccharide having a cyclic structure may be used alone or in combination of two or more.

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

(Polysaccharide (1))
In the polysaccharide (1), the cyclic structure may be a ring formed by an α-1,4-glucoside bond and an α-1,6-glucoside bond.

  The average degree of polymerization (number average degree of polymerization) of the cyclic structure (per one cyclic structure) may be, for example, 10 to 500, preferably 12 to 300, and more preferably 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, total number average degree of polymerization) of polysaccharide (1) should just be 50 or more, for example, 50-10000, Preferably it is 60-7000, More preferably, it is about 70-5000. It may be.

  In addition, the polysaccharide (1) may have one or more acyclic structures, and may usually have a plurality (for example, about 2 to 1000, preferably about 3 to 500). The average degree of polymerization (number average degree of polymerization) per such acyclic part (or part other than the cyclic structure of the polysaccharide (1)) is, for example, 10 or more (for example, 10 to 30), preferably 10 It may be about ~ 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 polysaccharide (1), the hydroxyl group (alcoholic hydroxyl group) may be derivatized (for example, etherified, esterified, grafted, etc.).

  Such polysaccharides (1) include polysaccharides known as “cluster dextrins”. 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.

(Polysaccharide (2))
In the polysaccharide (2), the cyclic structure may be a ring formed at least by 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 polysaccharide (2) may have an acyclic structure (for example, a straight chain structure) as long as it has the cyclic structure, but is usually composed (or formed) of only the cyclic structure. It may be a cyclic polysaccharide.

  In the polysaccharide (2), the hydroxyl group (alcoholic hydroxyl group) may be derivatized (for example, etherified, esterified, grafted, crosslinked).

  Such polysaccharides (2) include polysaccharides known as so-called “cycloamylose (or cycloamylose)”. Such a 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, An enzyme capable of forming a polysaccharide (2) with soluble starch, dextrin, starch debranch, partially hydrolyzed starch, amylose synthesized with morpholylase, and at least one selected from derivatives thereof (for example, D enzyme etc.) 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 having a cyclic structure may be used alone or in combination of two or more. In the present invention, the polysaccharide (1) (or cluster dextrin) can be particularly preferably used.

  In the auxiliary agent, the water-soluble polysaccharide may be composed of an oligosaccharide alone or a water-soluble polysaccharide having a cyclic structure, or may be composed of an oligosaccharide and a water-soluble polysaccharide having a cyclic structure. By properly using these water-soluble polysaccharides, the melt viscosity in the preparation of the dispersion can be adjusted, and the inorganic particles are effectively unevenly distributed in the shell according to the combination of the first thermoplastic resin and the second thermoplastic resin. be able to.

  When combining an oligosaccharide and a polysaccharide having a cyclic structure, the ratio between the oligosaccharide and the polysaccharide having a cyclic structure is the former / the latter (weight ratio) = 1/99 to 99/1, preferably 5/95 to It may be about 95/5, more preferably about 10/90 to 90/10 (for example, 15/85 to 85/15).

(Water-soluble plasticizing component)
The auxiliary agent further comprises a water-soluble plasticizing component for plasticizing the water-soluble polysaccharide [oligosaccharide (eg, oligosaccharide having a number of sugars of 6 or more sugars) and / or a water-soluble polysaccharide having a cyclic structure]. May be included. When a water-soluble polysaccharide and a water-soluble plasticizing component are combined, even a water-soluble polysaccharide (such as an oligosaccharide) that is thermally decomposed can be effectively plasticized or softened. The melting point or softening point of the plasticizing component may be equal to or lower than the thermal deformation temperature (the Vicat softening point) of the thermoplastic resin (the first thermoplastic resin and the second thermoplastic resin) constituting the core and the shell. Good.

  The water-soluble plasticizing component may be composed of saccharides (for example, monosaccharides, disaccharides, etc.), sugar alcohols, etc., and such saccharides may be composed of reducing sugars. The monosaccharide may be composed of triose, tetrose, pentose, hexose, heptose, octose, nonose, decose, dodecose, etc., and the disaccharide may be composed of homo- and heterodisaccharides of the monosaccharide. Sugar alcohols include tetritol (eg, erythritol), pentitol (eg, pentaerythritol, arabitol, ribitol, xylitol, etc.), hexitol (eg, sorbitol, dulcitol, mannitol, etc.), heptitol, octitol, nonitol, dexitol, doditol, etc. You may comprise. Of these sugar alcohols, erythritol, pentaerythritol, arabitol, ribitol, xylitol, sorbitol, dulcitol and mannitol are preferred.

  The sugar alcohol often contains at least one sugar alcohol selected from erythritol, pentaerythritol, and xylitol. A preferred water-soluble plasticizing component is a sugar alcohol.

  In the auxiliary agent, the ratio between the water-soluble polysaccharide and the plasticizing component is the former / the latter (weight ratio) = 99/1 to 20/80, preferably 95/5 to 30/70, more preferably 90/10. It may be about 40/60. Details of the auxiliary oligosaccharide and the plasticizing component are described in JP-A No. 2004-51942. Details of the sugar alcohol are described in JP-A-2005-162841.

  The ratio between the polysaccharide having a cyclic structure and the water-soluble plasticizing component is the former / the latter (weight ratio) = 99/1 to 20/80, preferably 95/5 to 30/70, more preferably 90/10. About 40/60 may be sufficient. In some cases, the average particle size of the composite resin particles can be adjusted depending on the proportion of the plasticizing component. When the proportion of the plasticizing component increases, resin particles having a large average particle size tend to be generated.

  In the dispersion of the present invention, the ratio between the composite resin particles and the auxiliary agent is, for example, that the auxiliary agent constitutes a continuous phase and the composite resin particle constitutes a dispersed phase (discontinuous phase) in the dispersion. Any quantitative ratio may be used. For example, the former / the latter (weight ratio) = 5/95 to 50/50, preferably 10/90 to 40/60, and more preferably about 15/85 to 35/65.

(Method for producing dispersion)
Although the dispersion of the present invention is not limited, it usually melts the first thermoplastic resin, the second thermoplastic resin, the inorganic particles, and the auxiliary agent (and other components as necessary). It can be produced by kneading (or melt mixing). Here, by selecting a combination of the first thermoplastic resin and the second thermoplastic resin, or selecting a kind of auxiliary agent, the composite resin particles (that is, a core-shell structure in which inorganic particles are unevenly distributed in the shell) Composite resin particles) can be obtained. In the production of the dispersion, the proportion of each component used (the proportion of the first thermoplastic resin and the second thermoplastic resin, the proportion of inorganic particles, etc.) is the same as described above. In the present invention, since the inorganic particles can be unevenly distributed in the core-shell structure shell at a high level, the proportion of each component (for example, inorganic particles) used as a raw material can be accurately reflected in the composite resin particles.

  In the melt-kneading, the inorganic particles may be mixed independently or individually with the first thermoplastic resin and / or the second thermoplastic resin, and from the first thermoplastic resin and the second thermoplastic resin. You may make it contain previously in the selected at least one thermoplastic resin.

  In the preparation of the dispersion, when a thermoplastic resin containing inorganic particles in advance is used, the inorganic fine particles are likely to be unevenly distributed in the composite resin particles. Specifically, the dispersion includes (i) a thermoplastic resin composition containing a first thermoplastic resin and inorganic particles (or a first thermoplastic resin containing inorganic particles (masterbatch)), a second It may be prepared by melt-kneading a thermoplastic resin and the auxiliary agent. (Ii) A thermoplastic resin composition (or inorganic) containing a first thermoplastic resin, a second thermoplastic resin and inorganic particles. A second thermoplastic resin containing particles (masterbatch)) and the auxiliary may be prepared by melt-kneading, and (iii) a thermoplastic resin composition containing the first thermoplastic resin and inorganic particles And a thermoplastic resin composition containing the second thermoplastic resin and inorganic particles, and the auxiliary agent may be prepared by melt-kneading. In particular, in the present invention, it seems that there are many cases where the composite resin particles of the present invention can be efficiently obtained when inorganic particles are contained in advance in at least the second thermoplastic resin (the above-described (ii) or (iii)). is there.

  In preparation of these dispersions, at least a part of the inorganic particles may be contained in the first thermoplastic resin and / or the second thermoplastic resin (that is, a part of the inorganic particles is contained, and the remaining part). May be mixed separately), or all of them may be contained in the first thermoplastic resin and the second thermoplastic resin.

  The thermoplastic resin composition (a thermoplastic resin composition containing a first thermoplastic resin and inorganic particles, a thermoplastic resin composition containing a second thermoplastic resin and inorganic particles) is a first or second heat. Although it will not specifically limit if an inorganic particle can be made to contain in a plastic resin, Usually, the method of melt-mixing (melt blending) the said thermoplastic resin (1st thermoplastic resin or 2nd thermoplastic resin) and an inorganic particle. Can be prepared. That is, the thermoplastic resin composition may be a molten mixture (melt kneaded material) of a thermoplastic resin and inorganic particles.

  In the preparation of the thermoplastic resin composition, the melt-kneading can be performed using a conventional kneader (for example, a single or twin screw extruder, a kneader, a calender roll, a Banbury mixer, a Brabender, etc.). The melt-kneading may be performed by using these kneaders (or a mixer or a disperser) alone or in combination of two or more.

  The shape of the thermoplastic resin composition (composition used for melt mixing with the matrix component) is not particularly limited, and may be in the form of powder or pellets.

  In preparation of the dispersion, melt-kneading (including the case of using the thermoplastic resin composition) can be performed in the same manner as the preparation of the composition, and a conventional kneader (for example, uniaxial or biaxial). An axial screw extruder, a kneader, a calender roll, a Brabender, etc.) can be used. Prior to kneading, each component may be preliminarily processed into a powder form with a freeze pulverizer or the like, or the composition and the matrix component may be prekneaded with a Henschel mixer, a tumble mixer, a ball mill, or the like.

  The melt-kneaded composition (dispersion) may be in the form of a lump or the like, and is subjected to molding (pre-molding) to form a preform from the viewpoint of removing matrix components (that is, auxiliary agents). May be. The shape of the preform (or dispersion) is not particularly limited, and is a zero-dimensional shape (granular, pellet-like, etc.), a one-dimensional shape (strand-like, rod-like, etc.), or a two-dimensional shape (plate-like, sheet-like) Or a three-dimensional shape (such as a tube or a block).

  In addition, kneading | mixing temperature and shaping | molding processing temperature can be suitably set according to the raw material used, for example, 90-300 degreeC, Preferably it is 110-260 degreeC (for example, 130-250 degreeC), More preferably. Is about 140 to 240 ° C. (for example, 150 to 240 ° C.), particularly about 170 to 230 ° C. (for example, 180 to 220 ° C.). 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 dispersion of the present invention is prepared as described above. Such a dispersion contains the composite resin particles, and the composite resin particles are a combination of the first thermoplastic resin and the second thermoplastic resin (as described above). By selecting a combination of core-shell structures) and types of auxiliaries, they are unevenly distributed in the shell and contain inorganic particles. Examples of typical dispersions (or composite resin particles) including the composite resin particles in which inorganic particles are unevenly distributed in the shell are shown below.

  (A) a first thermoplastic resin, a thermoplastic resin composition containing a second thermoplastic resin and inorganic particles (particularly a melt-kneaded product of the second thermoplastic resin and inorganic particles), and at least an oligosaccharide A dispersion obtained by melt-kneading an incompatible auxiliary agent [in particular, an incompatible auxiliary agent composed of an oligosaccharide and a water-soluble plasticizing component (such as a sugar alcohol)].

  In such a dispersion (A), composite resin particles in which inorganic particles are unevenly distributed in the shell are dispersed in an incompatible auxiliary agent. In the dispersion (A), the inorganic particles are likely to be unevenly distributed in the shell, probably because the inorganic particles are previously contained in the second thermoplastic resin. In such a dispersion (A), in particular, the first thermoplastic resin is composed of at least a cyclic polyolefin polymer, and the second thermoplastic resin is composed of at least a (meth) acrylic polymer. May be. When the first thermoplastic resin and the second thermoplastic resin are configured in such a combination, the inorganic particles can be unevenly distributed in the shell with high accuracy.

  Further, in the dispersion (A), the combination of the second thermoplastic resin, the inorganic particles, and the auxiliary agent is such that the inorganic particles are dispersed in the dispersion in which the second thermoplastic resin as the dispersed phase is dispersed in the auxiliary agent. In many cases, the combination is included in the second thermoplastic resin. By selecting such a combination, it becomes easy to efficiently obtain composite resin particles in which inorganic particles are unevenly distributed in the shell.

  (B) A thermoplastic resin composition containing a first thermoplastic resin and inorganic particles (particularly a melt-kneaded product of the first thermoplastic resin and inorganic particles), and a heat containing the second thermoplastic resin and inorganic particles. Incompatible auxiliary agent comprising a plastic resin composition (particularly a melt-kneaded product of the second thermoplastic resin and inorganic particles) and at least a water-soluble polysaccharide having a cyclic structure [particularly, a water-soluble polybasic having a cyclic structure] A dispersion obtained by melt-kneading a saccharide and an incompatible auxiliary agent composed of a water-soluble plasticizing component (such as a sugar alcohol).

  In such a dispersion (B), as described above, composite resin particles in which inorganic particles are unevenly distributed in the shell are dispersed in an incompatible auxiliary agent. In the dispersion (B), since the auxiliary agent is composed of a water-soluble polysaccharide having a cyclic structure having a high viscosity at the melting temperature, the inorganic particles contained in the first thermoplastic resin migrate to the core side. By doing so, it seems that inorganic particles can be unevenly distributed in the shell efficiently. In such a dispersion (B), in particular, the first thermoplastic resin is composed of at least a cyclic polyolefin polymer, and the second thermoplastic resin is composed of at least a (meth) acrylic polymer. May be. When the first thermoplastic resin and the second thermoplastic resin are configured in such a combination, the inorganic particles can be unevenly distributed in the shell with higher accuracy.

  Further, in the dispersion (B), the combination of the first thermoplastic resin, the inorganic particles, and the auxiliary agent is such that the inorganic particles are dispersed in the dispersion in which the first thermoplastic resin as the dispersed phase is dispersed in the auxiliary agent. In many cases, the combination is included in the first thermoplastic resin. Further, the combination of the second thermoplastic resin, the inorganic particles, and the auxiliary agent is obtained by dispersing the second thermoplastic resin as a dispersed phase in the auxiliary agent in which the inorganic particles are formed of the second thermoplastic resin. Often the combination is present on the surface. By selecting such a combination, it becomes easy to efficiently obtain composite resin particles in which inorganic particles are unevenly distributed in the core.

  In these dispersions (dispersion (A), dispersion (B)), the inorganic particles are particularly nanoparticles [or nano-sized particles, for example, inorganic particles having an average primary particle size of 50 nm or less (particularly metal oxide). Product particles)]. The inorganic particles may be inorganic particles that have been surface-treated (or hydrophobized). When inorganic particles that have been surface-treated (hydrophobized) are used, migration of the inorganic particles to the auxiliary agent (matrix) is likely to be suppressed, and the inorganic particles are often unevenly distributed in the core.

  The composite resin particles can be obtained by eluting the auxiliary from the dispersion obtained as described above. That is, composite resin particles can be obtained by elution treatment of the dispersion with a solvent that dissolves the auxiliary agent.

  The solvent may be any solvent that dissolves the auxiliary and is insoluble (not soluble) in the composite resin particles, and a suitable solvent is a hydrophilic solvent (aqueous solvent). As the hydrophilic solvent (aqueous solvent), for example, water, a water-soluble solvent (for example, alcohols (ethanol, isopropanol, etc.), ethers (cellosolve, etc.), etc.) can be used. These aqueous solvents are preferably water and / or alcohol-based solvents, and may be a single or a mixed solvent of two or more. The elution solvent is preferably a solvent composed mainly of at least water (including a mixed solvent), particularly a solvent composed of water.

  When a water-soluble auxiliary agent (water-soluble sugar composition) composed of oligosaccharides and / or cyclic polysaccharides is used as an auxiliary agent, the auxiliary agent can be easily dissolved with water to form composite resin particles and auxiliary agents. While being able to isolate | separate, it can prevent that the viscosity of the extract which the adjuvant melt | dissolved becomes high.

  The elution of the auxiliary may be performed by a conventional method, for example, by immersing and dispersing the dispersion (or preform) in the solvent, and elution or washing (transferring to the solvent) of the auxiliary. it can. In addition, in order to accelerate | stimulate dispersion | distribution and elution of an adjuvant, you may stir. The auxiliary agent may be eluted, for example, under pressure, but can usually be eluted under normal pressure (for example, about 100,000 Pa) or reduced pressure. The elution temperature of the auxiliary agent is usually a temperature below the melting point or softening point of the thermoplastic resin constituting the composite resin particles, for example, about 10 to 100 ° C., 25 to 80 ° C. (for example, 40 to 80 ° C.). is there. The composite resin particles can be recovered by separation using a conventional separation (recovery) method, for example, filtration, centrifugation, etc., and if necessary, washed and dried. In addition, about the isolation | separation or collection | recovery method of composite resin particle, Unexamined-Japanese-Patent No. 2005-162797, Unexamined-Japanese-Patent No. 2006-328219, etc. can be referred.

  The composite resin particles can usually be recovered from the dispersion containing the composite resin particles after the elution treatment. In the elution treatment, the auxiliary may be discharged as a solution of the solvent leaving only the composite resin particles, the dispersion is eluted or washed with a solvent, the auxiliary is dissolved, and the composite resin particles It is useful to produce and recover a dispersion or extract in which is dispersed.

  In such collection, if the specific gravity of the composite resin particles is small and separated and collected, the resin particles can be obtained easily and efficiently. In this method, by adjusting the concentration (degree of dilution or concentration) of the auxiliary agent in the dispersion or extract, the dispersion is combined with an upper layer having a high content ratio (existence ratio) of composite resin particles, The resin particles can be separated into a lower layer with a small content ratio (existence ratio), and the composite resin particles can be efficiently recovered from the upper layer. That is, in a dispersion in which composite resin particles are dispersed in a solution (in particular, an aqueous solution such as an aqueous solution) containing a solute (in particular, a water-soluble solute or auxiliary agent), the viscosity and density of the solution are set to a specific range or condition. By adjusting so that, even if the particle diameter of the composite resin particles is small, particles can be efficiently separated and recovered from the dispersion, and even if the concentration of the auxiliary agent in the dispersion or extract is low, The solute can be efficiently recovered from the dispersion or solution. This method will be described in detail below.

  In general, when a water-soluble polymer is used as an auxiliary agent, the viscosity of the aqueous solution is high, and it is difficult to separate the composite resin particles by filtration or the like. However, the solvent (C) is added to the solution (dispersion) or extract (E) in which the composite resin particles (A) are dispersed, containing the auxiliary agent (B) as a solute, and the dispersion Alternatively, if the characteristics of the extract (E) are adjusted so as to satisfy the following conditions (1), (2) and (3), the resin particles can be easily separated and recovered by filtration or the like.

(1) The viscosity of the dispersion liquid (E) is 200 mPa · s or less at 25 ° C. (2) The difference ρD−ρB between the density ρD of the dispersion liquid (E) and the density ρB of the auxiliary agent (B) is 25 At 0 ° C., 0.02 g / cm ³ or more (3) The number average particle diameter of the composite resin particles (A) is 100 μm or less.

  Such a dispersion (E) is separated into an upper layer liquid and a lower layer liquid, and the composite resin particles are present in a high concentration in the upper layer liquid, and almost no composite resin particles are present in the lower layer liquid. Can be filtered off. More specifically, by adjusting the dispersion (E) to the viscosity and density, layer separation between a layer containing a lot of composite resin particles and a layer containing a lot of solutes can be facilitated, and the separation efficiency of the composite resin particles can be improved. High dispersion can be obtained. In particular, in the dispersion liquid, by adjusting to the viscosity and density, the difference between the density of the auxiliary agent and the density of the solvent is small, and even when it is difficult to separate the particles by a normal method, the particles are efficiently dispersed. It can be recovered.

  In general, when a composite resin particle is produced by the melt-kneading dispersion method, if a water-soluble polymer is used as the auxiliary agent (B), the solution viscosity of the extract (E) becomes too high and the solution viscosity is lowered. Then, the dilution rate of the diluted extract (E) becomes an unrealistic dilution rate, and the abundance ratio of the composite resin particles (A) in the diluted extract (E) becomes extremely small. Accordingly, the filtration efficiency or separation efficiency of the diluted extract (E) is extremely low, which is not industrially feasible. And in the extract (E) combining a general resin and a water-soluble polymer, the above conditions (1) and (2) are contradictory, and the dilution ratio is set to satisfy the condition (1). If it is increased, the specific gravity of the extract (E) becomes small and the condition (2) cannot be satisfied. If the condition (2) is satisfied, the solution viscosity becomes too high to satisfy the condition (1). Therefore, it is difficult to apply the above method to the recovery of composite resin particles by such a combination of components.

  However, the density of the composite resin particles is low, and the conditions (1) and (2) can be easily satisfied by appropriately diluting the extract (E) with a solvent such as water as necessary. If the said collection method is used, even if it uses the auxiliary | assistant (B) comprised by water-soluble polymer by filtering only an upper layer liquid, composite resin particle | grains (E) from the diluted dispersion liquid or extract liquid (E) will be used. A) can be recovered. In particular, when a water-soluble auxiliary agent (water-soluble sugar composition) composed of an oligosaccharide and / or a cyclic polysaccharide is used as the auxiliary agent (B), the solution viscosity of the dispersion or the extract (E) can be reduced, The above conditions (1) and (2) can be easily satisfied, and composite resin particles can be efficiently produced without the need for increasing the dilution rate.

  The composite resin particles of the present invention are used in various applications, for example, image forming materials such as toner and ink, paints and coating agents (eg, powder paints), fillers (eg, fillers such as paints, insulating fillers). , Anti-blocking agent or lubricant (for example, anti-blocking agent for moldings), spacer (spacer for liquid crystal panel, etc.), carrier, base particles of secondary processed particles such as conductive particles, cosmetic materials, compression molding and laser molding It can be suitably used as a raw material for molding processing using powders such as, a light scattering additive (light diffusing agent) for flat panel displays and the like.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

  In the examples and comparative examples, the following thermoplastic resins, inorganic particles and auxiliaries were used.

(Thermoplastic resin)
Cycloolefin copolymer (manufactured by Ticona, cyclic polyolefin resin TOPAS (registered trademark) 5013S-04) polystyrene (manufactured by Toyo Styrene Co., Ltd., G100C)
Polymethyl methacrylate (manufactured by Asahi Kasei Chemicals Corporation, Delpet 720V)
Polyamide 12 (manufactured by Daicel Degussa, Z9004).

(Inorganic particles)
Titanium oxide particles (manufactured by Teika Co., Ltd., SMT-500SAM, surface-treated product, average primary particle size 15 nm)
Zinc oxide particles (A) (manufactured by Teika Co., Ltd., MZ-505M, surface treated product, average primary particle size 20-30 nm)
Zinc oxide particles (B) (Sumitomo Osaka Cement Co., Ltd., Zn350 (Si (4) G)).

(Auxiliary)
Oligosaccharide (starch sugar, manufactured by Towa Kasei Kogyo Co., Ltd., reduced starch saccharified product “PO-10”)
Water-soluble polysaccharide having a cyclic structure (trade name “Cluster Dextrin”, manufactured by Nippon Food Chemicals Co., Ltd.)
Sugar alcohol (sorbitol, manufactured by Towa Kasei Kogyo Co., Ltd., sorbit).

Example 1
80 parts by weight of polymethyl methacrylate and 20 parts by weight of titanium oxide particles were melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 10 minutes under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. A polymethyl methacrylate resin composition (block) containing titanium oxide particles was prepared and cut into small pieces.

  Then, an auxiliary agent 100 composed of 7.5 parts by weight of a polymethyl methacrylate resin composition cut into small pieces, 22.5 parts by weight of a pellet-shaped cycloolefin copolymer, 80 parts by weight of an oligosaccharide and 20 parts by weight of a sugar alcohol. The parts by weight were melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 5 minutes under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. to obtain a dispersion (1A).

  The obtained dispersion (1A) was immersed in 25 ° C. hot water to obtain a suspension of composite resin particles. Using a membrane membrane (pore size 0.45 μm, made of polyvinylidene fluoride), insolubles were filtered off from the suspension solution to recover composite resin particles. The recovered composite resin particles were dispersed in distilled water 20 times by weight with respect to the particles, and stirred for 10 minutes using a magnetic stirrer to obtain a suspension. Thereafter, again using a membrane membrane (pore size 0.45 μm, made of polyvinylidene fluoride), insolubles were filtered off from the suspension solution to recover composite resin particles.

  The obtained composite resin particles are mixed with an epoxy resin adhesive (manufactured by Konishi Co., Ltd., Bondquick 5) to prepare a lump with the resin particles dispersed therein, and a thickness of about 0.05 μm by a microtome. After cutting into ~ 0.2 μm ultra-foil slices, the structure was observed using a transmission electron microscope (manufactured by JEOL Ltd., TEM, JEM-1200EXII). Composite resin particles having a core-shell structure with methyl as a shell were obtained, and the titanium oxide particles were unevenly distributed in the shell and contained in the composite resin particles. A transmission electron micrograph is shown in FIG.

  Moreover, the obtained composite resin particle was observed with the scanning electron microscope (the JEOL Co., Ltd. make, FE-SEM, JSM-6700F), and the photograph of the surface shape and the whole shape was obtained. 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 resulting composite resin particles have a number average particle size (Dn) of 8.94 μm, a standard deviation of Dn of 5.72, a volume average particle size (Dw) of 18.17 μm, Dw / Dn of 2.03, and a CV value. Was 64.0%.

  Also, 80 parts by weight of polymethyl methacrylate and 20 parts by weight of titanium oxide particles were melted by Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 10 minutes at a rotational speed of 100 rpm and a set temperature of 220 ° C. A polymethyl methacrylate resin composition (block) containing titanium oxide particles was prepared and cut into small pieces. Then, 30 parts by weight of a polymethyl methacrylate resin composition cut into a small amount and 100 parts by weight of an auxiliary agent composed of 80 parts by weight of oligosaccharide and 20 parts by weight of sugar alcohol were combined with Brabender (manufactured by Toyo Seiki Co., Ltd., (Laboplast mill) was melt-kneaded for 5 minutes under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. to obtain a dispersion (1B). From the resulting dispersion (1B), resin particles (resin particles not containing a cycloolefin copolymer) were recovered in the same manner as described above. When the obtained resin particles were observed by the same method as described above, the titanium oxide particles were entirely dispersed and contained in the polymethyl methacrylate particles.

(Example 2)
80 parts by weight of polymethyl methacrylate and 20 parts by weight of zinc oxide particles (A) were melted for 10 minutes by Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) under the conditions of a rotational speed of 100 rpm and a set temperature of 220 ° C. A polymethyl methacrylate resin composition (block) containing zinc oxide particles (A) was prepared and kneaded.

  Then, an auxiliary agent 100 composed of 7.5 parts by weight of a polymethyl methacrylate resin composition cut into small pieces, 22.5 parts by weight of a pellet-shaped cycloolefin copolymer, 80 parts by weight of an oligosaccharide and 20 parts by weight of a sugar alcohol. The parts by weight were melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) at a rotational speed of 100 rpm and a set temperature of 220 ° C. for 5 minutes to obtain a dispersion (2A).

  Composite resin particles were recovered from the obtained dispersion (2A) by the same method as in Example 1.

  The obtained composite resin particles were observed by the same method as in Example 1. As a result, core-shell composite resin particles having a cycloolefin copolymer as a core and polymethyl methacrylate as a shell were obtained, and zinc oxide particles ( A) was unevenly distributed in the shell and contained in the composite resin particles. A transmission electron micrograph is shown in FIG.

  And the volume average particle diameter and the number average particle diameter were obtained from the obtained composite resin particles by the same method as in Example 1. The obtained composite resin particles have a number average particle diameter (Dn) of 7.96 μm, a standard deviation of Dn of 4.97, a volume average particle diameter (Dw) of 17.51 μm, Dw / Dn of 2.20, and a CV value. Was 62.4%.

  In addition, 80 parts by weight of polymethyl methacrylate and 20 parts by weight of zinc oxide particles (A) were subjected to a Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. The mixture was melt-kneaded for 10 minutes to prepare a polymethyl methacrylate resin composition (block) containing zinc oxide particles and cut into small pieces. Then, 30 parts by weight of a polymethyl methacrylate resin composition cut into a small amount and 100 parts by weight of an auxiliary agent composed of 80 parts by weight of oligosaccharide and 20 parts by weight of sugar alcohol, Brabender (manufactured by Toyo Seiki Co., Ltd., (Laboplast mill) was melt-kneaded for 5 minutes under the conditions of a rotational speed of 100 rpm and a set temperature of 220 ° C. to obtain a dispersion (2B). From the resulting dispersion (2B), resin particles (resin particles not containing a cycloolefin copolymer) were recovered by the same method as described above. When the obtained resin particles were observed by the same method as described above, the zinc oxide particles (A) were entirely dispersed and contained in the polymethyl methacrylate particles.

(Example 3)
Melting and kneading 80 parts by weight of cycloolefin copolymer and 20 parts by weight of zinc oxide particles (A) with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 10 minutes at a rotational speed of 100 rpm and a set temperature of 220 ° C. Then, a cycloolefin copolymer resin composition (block) containing zinc oxide particles (A) was prepared and cut into small pieces.

  Further, 80 parts by weight of polymethyl methacrylate and 20 parts by weight of zinc oxide particles (A) were added by Brabender (manufactured by Toyo Seiki Co., Ltd., Labo Plast Mill) at a rotational speed of 100 rpm and a set temperature of 220 ° C. The mixture was melt-kneaded for a minute to prepare a polymethyl methacrylate resin composition (block) containing zinc oxide particles (A) and cut into small pieces.

  Then, 22.5 parts by weight of cycloolefin copolymer resin composition cut into small pieces, 7.5 parts by weight of polymethyl methacrylate resin composition cut into small pieces, 75 parts by weight of water-soluble polysaccharide having a cyclic structure, and 25 sugar alcohols 100 parts by weight of an auxiliary agent composed of parts by weight was melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 5 minutes at a rotational speed of 100 rpm and a set temperature of 220 ° C. (3A) was obtained.

  Composite resin particles were recovered from the obtained dispersion (3A) by the same method as in Example 1.

  The obtained composite resin particles were observed by the same method as in Example 1. As a result, core-shell composite resin particles having a cycloolefin copolymer as a core and polymethyl methacrylate as a shell were obtained. Despite the inclusion of zinc oxide particles (A) in advance, the zinc oxide particles (A) were unevenly distributed in the shell and included in the composite resin particles. A transmission electron micrograph is shown in FIG.

  In addition, from the electron micrograph, although it was a very small amount, zinc oxide particles that were aggregated and existed outside the composite resin particles were confirmed. Therefore, when the ratio of the zinc oxide particles (A) contained in the composite resin particles to the zinc oxide particles (A) used as a raw material was measured, it was 96.59%, and most of the used zinc oxide particles (A). Was found to be contained in the composite resin particles.

In addition, the ratio of the zinc oxide particles (A) contained in the composite resin particles is determined by using TG-DTA (differential thermogravimetric simultaneous measurement device) manufactured by Seiko Instruments Co., Ltd., EXSTAR6000 TG-DTA6300. Using a mold, the temperature was raised at a rate of temperature rise of 20 ° C./min, held at 550 ° C. for 5 minutes, and then cooled, and the combustion residue was measured.
(Ratio of inorganic fine particles contained in composite resin particles to inorganic particles used as raw material) =
(Weight of inorganic particles obtained by measurement) / (Weight of inorganic particles used as raw material) × 100 (% by weight).

  And the volume average particle diameter and the number average particle diameter were obtained from the obtained composite resin particles by the same method as in Example 1. The number average particle diameter (Dn) of the obtained composite resin particles is 1.63 μm, the standard deviation of Dn is 0.47, the volume average particle diameter (Dw) is 1.97 μm, Dw / Dn is 1.21, and the CV value Was 28.7%.

  Further, 80 parts by weight of the cycloolefin copolymer and 20 parts by weight of the zinc oxide particles (A) were added by Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. The mixture was melt-kneaded for minutes to prepare a cycloolefin copolymer resin composition (block) containing zinc oxide particles, which was cut into small pieces. Then, 30 parts by weight of a cycloolefin copolymer resin composition cut into small pieces and 100 parts by weight of an auxiliary agent composed of 75 parts by weight of a polysaccharide having a cyclic structure and 25 parts by weight of a sugar alcohol were added to Brabender (Toyo Seiki Co., Ltd.). ), Laboplast Mill), and melt kneaded for 5 minutes under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. to obtain a dispersion (3B). From the resulting dispersion (3B), resin particles (resin particles not containing polymethyl methacrylate) were recovered by the same method as described above. When the obtained resin particles were observed by the same method as described above, the zinc oxide particles (A) were entirely dispersed and contained in the cycloolefin copolymer particles.

  Furthermore, 80 parts by weight of polymethyl methacrylate and 20 parts by weight of zinc oxide particles (A) were added by Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. The mixture was melt-kneaded for 10 minutes to prepare a polymethyl methacrylate resin composition (block) containing zinc oxide particles and cut into small pieces. Then, 30 parts by weight of a polymethyl methacrylate resin composition cut into small pieces and 100 parts by weight of an auxiliary agent composed of 75 parts by weight of a polysaccharide having a cyclic structure and 25 parts by weight of sugar alcohol were combined with Brabender (Toyo Seiki ( (Made by Labo Plast Mill Co., Ltd.) was melt-kneaded for 5 minutes under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. to obtain a dispersion (3C). From the resulting dispersion (3C), resin particles (resin particles not containing a cycloolefin copolymer) were recovered by the same method as described above. When the obtained resin particles were observed by the same method as described above, the zinc oxide particles (A) were included so as to cover the surface of the polymethyl methacrylate particles.

(Reference Example 1)
80 parts by weight of cycloolefin copolymer and 20 parts by weight of titanium oxide particles are melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 10 minutes at a rotational speed of 100 rpm and a set temperature of 220 ° C. A cycloolefin copolymer resin composition (block) containing titanium particles was prepared and cut into small pieces.

  Then, an auxiliary agent 100 composed of 22.5 parts by weight of a cycloolefin copolymer resin composition cut into small pieces, 7.5 parts by weight of polymethyl methacrylate in pellet form, 80 parts by weight of oligosaccharide and 20 parts by weight of sugar alcohol. The parts by weight were melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) at a rotational speed of 100 rpm and a set temperature of 220 ° C. for 5 minutes to obtain a dispersion (4A).

  Composite resin particles were recovered from the obtained dispersion (4A) by the same method as in Example 1.

  The obtained composite resin particles were observed by the same method as in Example 1. As a result, core-shell composite resin particles having a cycloolefin copolymer as a core and polymethyl methacrylate as a shell were obtained. It was unevenly distributed in the core and contained in the composite resin particles. A transmission electron micrograph is shown in FIG.

  And the volume average particle diameter and the number average particle diameter were obtained from the obtained composite resin particles by the same method as in Example 1. The resulting composite resin particles had a number average particle diameter (Dn) of 4.83 μm, a standard deviation of Dn of 2.82, a volume average particle diameter (Dw) of 9.84 μm, Dw / Dn of 2.04, and a CV value. Was 58.4%.

  In addition, 80 parts by weight of cycloolefin copolymer and 20 parts by weight of titanium oxide particles were melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 10 minutes at a rotational speed of 100 rpm and a set temperature of 220 ° C. Then, a cycloolefin copolymer resin composition (block) containing titanium oxide particles was prepared and cut into small pieces. Then, 30 parts by weight of the cycloolefin copolymer resin composition cut into 100 parts by weight and 100 parts by weight of an auxiliary agent composed of 80 parts by weight of oligosaccharide and 20 parts by weight of sugar alcohol were added to Brabender (Toyo Seiki Co., Ltd., Lab. The mixture (4B) was obtained by melt-kneading for 5 minutes under the conditions of a rotational speed of 100 rpm and a set temperature of 220 ° C. From the resulting dispersion (4B), resin particles (resin particles not containing polymethyl methacrylate) were recovered by the same method as described above. When the obtained resin particles were observed by the same method as described above, the titanium oxide particles were entirely dispersed and contained in the cycloolefin copolymer particles.

(Reference Example 2)
70 parts by weight of polystyrene and 30 parts by weight of zinc oxide particles (B) were melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 15 minutes at a rotational speed of 150 rpm and a set temperature of 200 ° C. A polystyrene resin composition (block) containing zinc oxide particles (B) was prepared and cut into small pieces.

  Then, 20 parts by weight of a chopped polystyrene resin composition, 5 parts by weight of the polyamide 12 in the form of pellets, and 100 parts by weight of an auxiliary agent composed of 75 parts by weight of oligosaccharide and 25 parts by weight of sugar alcohol, (Toyo Seiki Co., Ltd., Labo Plast Mill) was melt-kneaded for 10 minutes under the conditions of a rotational speed of 50 rpm and a preset temperature of 200 ° C. to obtain a dispersion (5A).

  Composite resin particles were recovered from the obtained dispersion (5A) by the same method as in Example 1.

  The obtained composite resin particles were observed by the same method as in Example 1. As a result, core-shell composite resin particles having polystyrene as a core and polyamide 12 as a shell were obtained, and zinc oxide particles (B) were shells. Among them, it was unevenly distributed near the interface with the core and contained in the composite resin particles. A transmission electron micrograph is shown in FIG.

  From the electron micrograph, it was confirmed that the zinc oxide particles (B) were present in an aggregated state outside the composite resin particles, although in a very small amount. Therefore, when the ratio of the zinc oxide particles (B) contained in the composite resin particles to the zinc oxide particles (B) used as a raw material was measured by the same method as described above, it was 94.09%, and the used zinc oxide It was found that most of the particles (B) were contained in the composite resin particles.

  And the volume average particle diameter and the number average particle diameter were obtained from the obtained composite resin particles by the same method as in Example 1. The number average particle diameter (Dn) of the obtained composite resin particles is 1.46 μm, the standard deviation of Dn is 1.42, the volume average particle diameter (Dw) is 5.95 μm, Dw / Dn is 4.07, and CV value. Was 96.9%.

  Also, 70 parts by weight of polystyrene and 30 parts by weight of zinc oxide particles (B) were melted by Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 15 minutes at a rotational speed of 150 rpm and a set temperature of 200 ° C. A polystyrene resin composition (block) containing zinc oxide particles was prepared and kneaded. Then, 25 parts by weight of a polystyrene resin composition cut into small pieces and 100 parts by weight of an auxiliary agent composed of 75 parts by weight of oligosaccharide and 25 parts by weight of sugar alcohol were combined with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill). ) For 10 minutes under conditions of a rotation speed of 100 rpm and a set temperature of 200 ° C. to obtain a dispersion (5B). From the resulting dispersion (5B), resin particles (resin particles not containing polyamide 12) were recovered by the same method as described above. When the obtained resin particles were observed by the same method as described above, the zinc oxide particles (B) were included so as to cover the polystyrene particle surfaces.

(Reference Example 3)
Melting and kneading 80 parts by weight of cycloolefin copolymer and 20 parts by weight of zinc oxide particles (A) with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 10 minutes at a rotational speed of 100 rpm and a set temperature of 220 ° C. Then, a cycloolefin copolymer resin composition (block) containing zinc oxide particles (A) was prepared and cut into small pieces.

  The cycloolefin copolymer resin composition is cut into 22.5 parts by weight, 7.5 parts by weight of a polymethyl methacrylate resin, 75 parts by weight of a water-soluble polysaccharide having a cyclic structure, and 25 parts by weight of a sugar alcohol. 100 parts by weight of the auxiliary was melt-kneaded with Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) for 5 minutes under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. to obtain a dispersion.

  Composite resin particles were recovered from the obtained dispersion by the same method as in Example 1.

  The obtained composite resin particles were observed by the same method as in Example 1. As a result, core-shell composite resin particles having a cycloolefin copolymer as a core and polymethyl methacrylate as a shell were obtained, and zinc oxide particles ( Although A) was contained in the shell of the composite resin particles, the amount thereof was very small, and many of them were present aggregated outside the composite resin particles. A transmission electron micrograph is shown in FIG.

  In addition, as mentioned above, the zinc oxide particle (A) which aggregated and existed outside the composite resin particle was confirmed. Therefore, when the ratio of the zinc oxide particles (A) contained in the composite resin particles to the zinc oxide particles (A) used as a raw material was measured by the same method as described above, it was 87.6%, and the zinc oxide used was It was found that a large amount of particles (A) existed outside the composite resin particles. And the volume average particle diameter and the number average particle diameter were obtained from the obtained composite resin particles by the same method as in Example 1. The number average particle diameter (Dn) of the obtained composite resin particles is 1.98 μm, the standard deviation of Dn is 0.77, the volume average particle diameter (Dw) is 2.71 μm, Dw / Dn is 1.37, CV value Was 38.9%.

(Reference Example 4)
80 minutes by weight of a polymethyl methacrylate resin and 20 parts by weight of zinc oxide particles (A) are subjected to 10 minutes under the conditions of a rotation speed of 100 rpm and a set temperature of 220 ° C. by Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill). The mixture was melt-kneaded to prepare a polymethyl methacrylate resin composition (block) containing zinc oxide particles (A) and cut into small pieces.

  And, it was composed of 7.5 parts by weight of a polymethyl methacrylate resin composition cut into small pieces, 22.5 parts by weight of a cycloolefin copolymer, 75 parts by weight of a water-soluble polysaccharide having a cyclic structure, and 25 parts by weight of a sugar alcohol. 100 parts by weight of the auxiliary agent was melt-kneaded with Brabender (manufactured by Toyo Seiki Co., Ltd., Labo Plast Mill) at a rotational speed of 100 rpm and a set temperature of 220 ° C. for 5 minutes to obtain a dispersion.

  Composite resin particles were recovered from the obtained dispersion by the same method as in Example 1.

  The obtained composite resin particles were observed by the same method as in Example 1. As a result, core-shell composite resin particles having a cycloolefin copolymer as a core and polymethyl methacrylate as a shell were obtained. (A) was hardly contained in the composite resin particles, and was present in an aggregated state outside the composite resin particles. A transmission electron micrograph is shown in FIG.

  And the volume average particle diameter and the number average particle diameter were obtained from the obtained composite resin particles by the same method as in Example 1. The number average particle diameter (Dn) of the obtained particles is 1.39 μm, the standard deviation of Dn is 0.90, the volume average particle diameter (Dw) is 2.70 μm, Dw / Dn is 1.95, and the CV value is 64. 9%.

FIG. 1 is a transmission electron micrograph of the composite resin particles obtained in Example 1. FIG. 2 is a transmission electron micrograph of the composite resin particles obtained in Example 2. FIG. 3 is a transmission electron micrograph of the composite resin particles obtained in Example 3. FIG. 4 is a transmission electron micrograph of the composite resin particles obtained in Reference Example 1. FIG. 5 is a transmission electron micrograph of the composite resin particles obtained in Reference Example 2. FIG. 6 is a transmission electron micrograph of the composite resin particles obtained in Reference Example 3. FIG. 7 is a transmission electron micrograph of the composite resin particles obtained in Reference Example 4.

Claims (7)

  Composite resin particles having a core-shell structure including a core composed of a first thermoplastic resin and a shell that is composed of a second thermoplastic resin different from the first thermoplastic resin and covers the core. A composite resin particle in which inorganic particles are unevenly distributed in the shell.   The first thermoplastic resin is at least one selected from cyclic polyolefin polymers and styrene polymers, and the second thermoplastic resin is a (meth) acrylic polymer, a polyamide polymer, and The composite resin particle according to claim 1, wherein the composite resin particle is at least one selected from vinyl alcohol polymers.   The composite resin particle according to claim 1, wherein the average primary particle diameter of the inorganic particles is 50 nm or less.   The composite resin particle according to claim 1, wherein the inorganic particle is a hydrophobic treated inorganic particle.   The composite resin particle according to claim 4, wherein the inorganic particle is an inorganic particle hydrophobized with a silicon-based surface treatment agent.   The ratio of the first thermoplastic resin and the second thermoplastic resin is the former / the latter (weight ratio) = 30/70 to 99/1, and the ratio of the inorganic particles is 0 with respect to the entire composite resin particles. The composite resin particle according to claim 1, which is 5 to 30% by weight.   A metal oxide in which the first thermoplastic resin is composed of at least a cyclic polyolefin polymer, the second thermoplastic resin is composed of at least a (meth) acrylic polymer, and the inorganic particles have an average primary particle diameter of 50 nm or less. The composite resin particle according to claim 1, which is a particle.