JP2010132848A - Resin particle containing inorganic filler, and dispersion thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin particle (composite resin particle) including an inorganic filler (such as a metal oxide) at high concentration (for example ≥50 wt.%). <P>SOLUTION: An inorganic filler (such as a metal oxide particle), a polymer, and an aid such as water-soluble polysaccharides are melt-mixed to prepare a dispersion including a resin particle containing the inorganic filler as a dispersed phase and the aid as a continuous phase, wherein the inorganic filler is included in the resin particle at high concentration by selecting, as an inorganic filler, a hydrophobized inorganic filler (for example, polysiloxane, a silane coupling agent having a hydrophobic group). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to polymer (particularly thermoplastic resin) particles containing an inorganic filler such as metal oxide particles, a dispersion containing the resin particles as a dispersed phase, and a method for producing the resin particles.

  As the resin particles containing inorganic particles (inorganic particles are combined), for example, toner or ink particles in which pigments are dispersed, resin particles for cosmetics in which inorganic particles having ultraviolet absorbing ability are combined, and the like are used. Yes. In such composite resin particles, various properties can be effectively expressed by including inorganic particles in the resin particles. For example, inorganic particles such as ultraviolet absorbers that can prevent dropping from the resin particles by containing (particularly encapsulating) colorants as inorganic particles in the resin particles, and can cause allergies. By encapsulating in the resin particles, the risk of developing allergic symptoms can be greatly reduced even when used as a cosmetic.

  Resin particles containing such inorganic particles can be obtained, for example, by a method of polymerizing a polymer monomer in the presence of inorganic particles. Japanese Patent No. 2636355 (Patent Document 1) has base material particles such as nylon polymer, and at least one kind of powder selected from zirconium oxide and aluminum oxide is supported on the surface of the base material particles. When obtaining composite particles in which at least one powder selected from titanium oxide and zinc oxide is dispersed inside the base material particles, the base material particles are made of, for example, nylon polymer. In the case of composition, heat and dissolve the cyclic lactam in paraffin or the like, add a desired amount of titanium oxide or zinc oxide powder, and while stirring, add a polymerization accelerator such as phosphorus trichloride to perform alkali polymerization. It is described that the particles can be made into particles. In this document, it is described that the quantitative ratio of titanium oxide or zinc oxide powder is in the range of 5 to 60% by weight with respect to the base material particles. However, in the method of this document, zirconium oxide having a much larger specific gravity with respect to the dispersion medium is dispersed in the base material particles while polymerizing in a dispersion medium such as paraffin. Therefore, in the examples, even if all monomers are polymerized and all are dispersed, titanium oxide or the like can be dispersed at most about 10% by weight with respect to the base material particles. Thus, resin particles containing titanium oxide or the like at a high concentration of 60% by weight cannot be obtained. That is, when polymerizing using paraffin as a solvent, since the specific gravity of paraffin is about 0.9, the density of the powder such as zirconium oxide having a sufficiently large density (for example, specific gravity of 4 or more) is high (for example, 40 wt% or more), the density of the resin particles increases (for example, 1.5 or more) and settles, as is clear from the fact that the zirconium oxide or the like is contained in the paraffin at a high concentration. The resin particle containing can not be obtained. In addition, since a shearing force cannot be sufficiently applied to the polymerization system, zirconium oxide or the like tends to be poorly dispersed in the resin particles. In this method, even if a large amount of zirconium oxide or the like is used, a large amount of zirconium oxide or the like that is not dispersed in the base material particles is by-produced and cannot be efficiently dispersed in the base material particles.

  In addition, if inorganic particles and a polymer are mixed under heating, the inorganic particles can be attached to or supported on the outer surface of the resin particles. In such a method, the resin particles can include the inorganic particles. Can not.

  A method is also known in which inorganic particles are combined with resin particles regardless of the polymerization method or the like. For example, JP-A-2005-179646 (Patent Document 2) discloses that a particulate dispersed phase composed of a meltable organic solid component (A) such as a polymer and a colorant (B) is at least The auxiliary component (C) is eluted from the dispersion dispersed in the matrix composed of the water-soluble auxiliary component (C) containing the oligosaccharide (C1), and the organic solid component (A) and the colorant (B And a method for producing particles composed of the above. According to this document, in the dispersed phase, the proportion of the colorant (B) is 0.001 to 200 parts by weight (for example, 0.001 to 100 parts by weight with respect to 100 parts by weight of the organic solid component (A)). ) It can be selected from a wide range. However, in the method of this document, depending on the type of the colorant, there is a possibility that it cannot be efficiently distributed to the polymer. Also in the examples of this document, the colorant can only be included in the resin particles at a ratio of at most about 30% by weight, and the colorant cannot be included at a high concentration. Such a tendency becomes more prominent as the particle size of the colorant increases, and as the amount of the colorant used increases, the amount of the colorant distributed to the matrix increases. Further, as the particle size increases, it becomes more difficult to uniformly disperse the colorant in the resin particles, and the colorant particles tend to aggregate at the interface with the matrix.

  In this document, when a colorant having a higher affinity for an organic solid component than a water-soluble auxiliary component is used, the colorant can be distributed to the dispersed phase side in the dispersion, and the use of the colorant Although it is described that the efficiency can be improved, a water-insoluble dye or pigment is exemplified as a colorant having a high affinity, and there is no description about a method for partitioning into a dispersed phase at a high concentration.

Japanese Patent No. 2636355 (Claims, page 2, column 4, lines 24 to 40, Examples) Japanese Patent Laying-Open No. 2005-179646 (claims, paragraph numbers [0069] and [0072], Examples)

  Accordingly, an object of the present invention is to provide resin particles containing an inorganic filler (metal oxide or the like) at a high concentration, a dispersion containing the resin particles as a dispersed phase, and a method for producing the resin particles.

  Another object of the present invention is to provide resin particles that can be contained in a high concentration even with relatively large inorganic fillers (for example, particles effective for light scattering having an average primary particle diameter of about 100 nm or more), An object of the present invention is to provide a dispersion containing the resin particles as a dispersed phase and a method for producing the resin particles.

  Still another object of the present invention is to provide a dispersion and a method for producing resin particles, which can efficiently and reliably produce resin particles containing an inorganic filler at a high concentration.

  Another object of the present invention is to achieve a high concentration without agglomerating the inorganic filler even if it is an inorganic filler having a relatively large size (for example, particles effective for light scattering having an average primary particle diameter of about 100 nm or more). An object of the present invention is to provide a dispersion that can be contained, and a method for producing resin particles.

  As a result of intensive studies to solve the above problems, the present inventors used an inorganic filler treated with a hydrophobizing agent such as an organosilicon compound as the inorganic filler, and the inorganic filler, the polymer, and the water-soluble Normal mixing (such as melt mixing of inorganic filler and polymer) in the polymer matrix of particles by using a dispersion obtained by melt-mixing with an auxiliary agent and using a water-soluble auxiliary agent as a matrix Inorganic fillers can be contained (encapsulated) at a high concentration that could not be realized by the above, especially by such a method, it is difficult to contain even higher concentrations than inorganic fillers on the order of nanosize. Even an inorganic filler having a relatively large size (for example, particles effective for light scattering or light shielding having an average primary particle diameter of about 100 nm or more) The resin particles can be reliably contained in a high concentration (and in a relatively uniformly dispersed form) without being distributed to the auxiliary matrix, and the shape of the resin particles can be made spherical. After preparing a masterbatch by melt-mixing the inorganic filler and polymer, the inorganic filler and the polymer can be directly used without going through a process such as melt-mixing the masterbatch (molten mixture) and the water-soluble auxiliary agent. It has been found that an inorganic filler can be reliably contained in a resin particle at a high concentration by melt-mixing a polymer and a water-soluble auxiliary agent in one step, and the present invention has been completed.

That is, the resin particles of the present invention are resin particles containing an inorganic filler in a proportion of 40% by weight or more. In this resin particle, the inorganic filler is hydrophobized with a hydrophobized inorganic filler [for example, at least one selected from an organosilicon compound (for example, polysiloxane and a silane coupling agent having a hydrophobic group). Inorganic filler] may be used. In the resin particles of the present invention, the inorganic filler may be an inorganic filler having a relatively large particle size, for example, an average primary particle size of 100 nm or more (for example, about 100 to 800 nm). In the present invention, even such an inorganic filler having a large particle diameter can be contained in the resin particles at a high concentration. The density of the inorganic filler is usually 4g / cm ³ or more (e.g., 4~10g / cm ³ or so) may be.

  In the representative resin particles, the inorganic filler is an inorganic filler hydrophobized with an alkoxysilane having a hydrocarbon group, the average particle diameter of the inorganic filler is 150 to 500 nm, and the inorganic filler is 50 to Resin particles contained in a proportion of 80% by weight are included. Further, the inorganic filler may be an inorganic filler hydrophobized with an alkoxysilane having an alkyl group having 4 or more carbon atoms.

  The present invention also includes a dispersion in which the resin particles (resin particles containing an inorganic filler in a proportion of 40% by weight or more) are dispersed in a continuous phase composed of a water-soluble auxiliary agent. The present invention also includes a method for producing the resin particles by eluting the continuous phase from the dispersion. This method may include a step of producing (or preparing) the dispersion by the following step (1) or step (2).

(1) Step of manufacturing (or preparing) a dispersion by melt-mixing (simultaneously melt-mixing) an inorganic filler, a polymer, and a water-soluble auxiliary agent (2) (2) A melt mixture of an inorganic filler and a polymer (ie, inorganic Step of manufacturing (or preparing) a dispersion by melt-mixing a filler and a polymer in advance and melt-mixing the resulting mixture) and a water-soluble auxiliary agent. In such a method, step (1) or ( In 2), prior to melt mixing, an inorganic filler and a polymer (for example, a polymer having a shape such as pellets or granules) may be further mixed without melting. In particular, in the above method, an inorganic filler that is hydrophobized with an organosilicon compound and has an average primary particle size of 100 nm or more is used as the inorganic filler, and a dispersion is produced (or prepared) by the step (1). Good.

  In this specification, terms such as “polymer” and “thermoplastic resin” refer to the definition of “new edition polymer dictionary” (published by Asakura Shoten, Society of Polymer Science: November 25, 1988, first edition). Also good. 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). In addition, when the term “resin” is used as a constituent material of a 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 may also be the same as “used to specify some polymers that are base materials for plastics”.

  The resin particles (composite resin particles) of the present invention contain an inorganic filler (such as a metal oxide) at a high concentration. Therefore, according to the kind of inorganic filler, excellent characteristics (for example, concealment properties) can be imparted to the resin particles. Moreover, in the present invention, even when the size of the inorganic filler is relatively large (for example, particles having an average primary particle diameter of 100 nm or more), the inorganic filler can be contained at a high concentration in the resin particles. Moreover, if the dispersion of this invention is used, the resin particle (especially spherical resin particle) which contains an inorganic filler in high concentration can be manufactured efficiently and reliably. In particular, in the present invention, by treating the inorganic filler with a specific hydrophobizing agent, even if the inorganic filler, the polymer, and the water-soluble auxiliary are directly melt-mixed, the inorganic filler is dissolved in the water-soluble auxiliary. Without being distributed to the matrix, it can be surely contained in the resin particles as the dispersed phase at a high concentration. Furthermore, when the dispersion of the present invention is used, even if the inorganic filler has a relatively large size, it is contained in the resin particles at a high concentration in a relatively uniformly dispersed form without agglomerating the inorganic filler. be able to.

FIG. 1 is an electron micrograph of the resin particles obtained in Example 1. FIG. 2 is an electron micrograph of the resin particles obtained in Example 2. FIG. 3 is an electron micrograph of the resin particles obtained in Example 6. FIG. 4 is an electron micrograph of a fracture surface of the dispersion obtained in Reference Example 1. FIG. 5 is an electron micrograph of a fracture surface of the dispersion obtained in Example 1. FIG. 6 is an electron micrograph of a fracture surface of the dispersion obtained in Example 2. FIG. 7 is an electron micrograph of a fracture surface of the dispersion obtained in Reference Example 4. FIG. 8 is an electron micrograph of a fracture surface of the dispersion obtained in Reference Example 5. FIG. 9 is an electron micrograph of a fracture surface of the dispersion obtained in Example 6. FIG. 10 is an electron micrograph of the cross section of the resin particle obtained in Reference Example 1. FIG. 11 is an electron micrograph of a cross section of the resin particle obtained in Example 1. FIG. 12 is an electron micrograph of the cross section of the resin particle obtained in Example 2. FIG. 13 is an electron micrograph of the cross section of the resin particle obtained in Reference Example 4. FIG. 14 is an electron micrograph of a cross section of the resin particle obtained in Reference Example 5. FIG. 15 is an electron micrograph of the cross section of the resin particle obtained in Example 6.

  The resin particles of the present invention are resin particles containing an inorganic filler at a specific high concentration. That is, the resin particles are composed of a polymer (resin) and an inorganic filler.

[High molecular]
The polymer constituting the resin particles may usually be a thermoplastic resin as long as the inorganic filler can be contained at a specific high concentration.

  Typical polymers include, for example, polyamide-based polymers, polyester-based polymers, polyurethane-based polymers, poly (thio) ether-based polymers [for example, polyacetal-based polymers, polyphenylene ether-based polymers, polysulfide-based polymers. Molecule, poly (thio) etherketone polymer (polyetherketone, polyetheretherketone, polyphenylene sulfide ketone, etc.), polycarbonate polymer, polysulfone polymer, polyimide polymer (eg, polyimide, polyether) Condensation-type thermoplastic resins such as imides and polyamide-imides); Vinyl-polymerized thermoplastic resins such as olefin polymers, (meth) acrylic polymers, and styrene polymers; polymers derived from natural products such as cellulose derivatives; Thermoplastic silicone polymer; thermoplasticity Elastomer and the like.

  These polymers can be used alone or in combination of two or more.

  Hereinafter, polyamide polymers, polyester polymers, olefin polymers, (meth) acrylic polymers, and styrene polymers will be described in detail as representative polymers.

(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 and an alicyclic polyamide polymer are used. A molecule is used. These polyamide polymers can be used alone or in combination of two or more.

Examples of the aliphatic polyamide polymer include condensates of C _4-10 alkylenediamine and C _4-20 alkanedicarboxylic acid (for example, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, polyamide 1212). Etc.), lactam (C _4-20 lactam such as ε-caprolactam, ω-laurolactam, etc.) or aminocarboxylic acid (carbon number C _4-20 aminocarboxylic acid such as ω-aminoundecanoic acid) alone or in combination Copolymer (for example, polyamide 6, polyamide 11, polyamide 12 etc.), copolyamide (for example, polyamide 6/11, polyamide 6/12, polyamide 66/11, polyamide 66/12 etc.) copolymerized with these polyamide components, etc. Is mentioned.

Further, the polyamide polymer includes 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.). Also included are polyester amides which are condensates of C _4-20 alkylene dicarboxylic acids and the like) and aliphatic diol components (C _2-12 alkylene glycols such as ethylene glycol, propylene glycol, butane diol, etc.).

(Polyester polymer)
Polyester polymers include polycondensation of dicarboxylic acid components and diol components, oxycarboxylic acid components (for example, oxybenzoic acid, oxynaphthoic acid, hydroxyphenylacetic acid, glycolic acid, lactic acid, oxycaproic acid, and derivatives thereof) Alternatively, homo- or copolyesters obtained by polycondensation (or ring-opening polymerization) of a lactone component (such as C _3-12 lactone such as ε-caprolactone) or polycondensation of these components can be used. The polyester polymer may be an aliphatic polyester, an alicyclic polyester, an aromatic polyester or a wholly aromatic polyester. Polyester polymers may be used alone or in combination of two or more.

Typical polyester polymers include, for example, polyalkylene arylate polymers (for example, poly C _2-6 alkylene-C _6-10 arylates such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate). -Based polyester, poly (1,4-cyclohexyldimethylene terephthalate, etc.), copolyester containing an alkylene arylate unit (eg, C _2-6 alkylene-arylate unit) as a main component (eg, 50% by weight or more) [ For example, a copolyester using (poly) oxy C _2-4 alkylene glycol (such as diethylene glycol) as part of the diol component, and a C _6-12 alicyclic dicarboxylic acid (eg, hexahydroterephthalate) as part of the dicarboxylic acid component acid Etc.) and isophthalic acid, and copolyesters using an asymmetric aromatic dicarboxylic acid such as phthalic acid] and the like.

(Olefin polymer)
Examples of the olefin polymer include, for example, α-C _2-6 olefin homopolymer or copolymer [for example, polyethylene (low density polyethylene, high density polyethylene, linear low density polyethylene), ethylene-propylene copolymer, etc. Polyethylene polymers, polypropylene polymers such as polypropylene, poly (methylpentene-1), etc.], copolymers of α-C _2-6 olefins and copolymerizable monomers (for example, ethylene-vinyl acetate) Copolymer, ethylene- (meth) acrylic acid copolymer or a salt thereof, ethylene- (meth) acrylic acid ester copolymer, etc.), cyclic olefin polymer, and the like. The olefin polymers may be used alone or in combination of two or more.

  The cyclic olefin polymer (cycloolefin polymer) may be a polymer having at least a polymerization component of a cyclic olefin (monocyclic olefin and / or polycyclic olefin). Examples of the polycyclic olefin include: Bi- to hexacyclic olefins, particularly norbornene monomers (or monomers having a norbornene skeleton, for example, norbornenes such as 2-norbornene and alkylnorbornene such as 5-methyl-2-norbornene, dicyclopentadiene Etc.). The cyclic olefin may have a substituent.

The cyclic olefin polymer may be a cyclic olefin homopolymer or copolymer, and a cyclic olefin and a copolymerizable monomer {for example, chain olefin [for example, α-olefins (for example, ethylene, propylene, C _2-10 α-olefins such as 1-butene, 1-pentene, 1-hexene, etc., particularly C _2-6 α-olefins)], (meth) acrylonitrile, (meth) acrylic monomers (for example, , (Meth) acrylic acid esters such as methyl (meth) acrylate, (meth) acrylic acid, etc.), unsaturated dicarboxylic acids or derivatives thereof (such as maleic anhydride)] (cycloolefin copolymers) There may be. Typical copolymerizable monomers include chain olefins (ethylene, propylene, 1-butene, etc.). The copolymerizable monomers may be used alone or in combination of two or more. In the copolymer, the proportion of the copolymerizable monomer (for example, α-olefins) is not particularly limited, and is a small proportion (for example, about 1 to 25 mol%, preferably about 2 to 20 mol%). Also good.

  The cyclic olefin polymer may be a polymer obtained by addition polymerization or a polymer obtained by ring-opening polymerization (such as ring-opening metathesis polymerization).

  The cyclic olefin polymer may be prepared by a conventional polymerization method (for example, addition polymerization using a Ziegler-type catalyst, ring-opening metathesis polymerization using a metathesis polymerization catalyst, etc.), and a commercially available product may be used. Also good. For example, the cyclic olefin polymer is from Ticona under the trade name “TOPAS”, from Nippon Zeon Co., Ltd. under the trade names “ZEONEX” “Zeonoa”, from JSR Corp. under the trade name “ARTON”, from Mitsui Chemicals, Inc. It can also be obtained as the product name “Apel”.

((Meth) acrylic polymer)
Examples of (meth) acrylic polymers include (meth) acrylic monomers ((meth) acrylic acid, (meth) acrylic acid C _1-18 alkyl ester, (meth) acrylic acid hydroxyalkyl, (meth) acrylic acid. Glycidyl, (meth) acrylonitrile, etc.) or copolymers, for example, poly (meth) acrylates such as poly (meth) methyl acrylate, methyl methacrylate- (meth) acrylic acid copolymers, methyl methacrylate -Acrylic acid ester- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, (meth) acrylic acid ester-styrene copolymer (MS polymer, etc.) and the like. The (meth) acrylic polymers may be used alone or in combination of two or more.

(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 ester-styrene copolymer (MS resin, etc.), styrene -Maleic anhydride copolymer, etc.), rubber-containing styrenic polymer [for example, block copolymer such as styrene-butadiene block copolymer; graft obtained by graft polymerization of at least styrene monomer in the presence of rubber component Polymers such as impact-resistant polystyrene (HIPS or rubber-grafted polystyrene resin), acrylonitrile -Graft copolymer using a rubber component such as ethylene propylene rubber E, acrylic rubber A, chlorinated polyethylene C, vinyl acetate polymer instead of butadiene rubber B of this butadiene-styrene copolymer (ABS resin). Polymers (AXS resins such as AES resin, AAS resin, ACS resin), graft copolymers using (meth) acrylic monomers (such as methyl methacrylate) instead of acrylonitrile (for example, methyl methacrylate-butadiene) Rubber-styrene copolymer (MBS resin, etc.)] and the like. Styrenic polymers may be used alone or in combination of two or more.

  In the present invention, an inorganic filler can be contained at a high concentration in a wide range of polymers regardless of the degree of hydrophobicity by using a dispersion described later.

(Inorganic filler)
The average particle diameter (primary particle diameter) of the inorganic filler (inorganic particles or filler) can be selected according to the size of the resin particles, for example, can be selected from a wide range of about 1 nm to 10 μm, and usually 2 nm to It may be about 1 μm, preferably 3 to 500 nm, more preferably about 5 to 300 nm.

  In particular, the average primary particle diameter of the inorganic filler is 100 nm or more (for example, 110 to 1000 nm), preferably 120 nm or more (for example, 130 to 800 nm), more preferably 140 nm or more (for example, 150 to 600 nm), usually 100 to 800 nm. [Preferably 150 to 500 nm (for example, 170 to 400 nm)] may be sufficient. In the present invention, even such an inorganic filler having a relatively large particle diameter can be reliably contained in the resin particles at a high concentration. The colored particles such as titanium oxide used in the examples of Patent Document 2 are particles having an average primary particle diameter of about several tens of nanometers.

The density of the inorganic filler, for example, 2 g / cm ³ or more (e.g., 2 to 50 g / cm ³⁾ can be selected from the range of, for example, 2.5 g / cm ³ or more (e.g., 2.7~40g / cm ^3), preferably 3 g / cm ³ or more (e.g., 3.2~30g / ^cm 3), may be more preferably 3.5 g / cm ³ or more (e.g., 3.7~20g / cm ³⁾ usually 4g / cm ³ or more (e.g., 4~10g / cm ³ or so) may be. Usually, the specific surface area of the inorganic filler, for example, 0.5 to 100 ² / g, preferably 1~60m ² / g, more preferably 3 to 50 m ² / g (e.g., 5 to 30 m ² / g) in extent There may be.

  Examples of the inorganic filler (inorganic particles or filler) include silica such as metal oxide (fine powder silica (anhydride), white carbon (hydrate)), alumina, titania, zirconia, titanium oxide, iron oxide, and strontium oxide. , Cerium oxide, 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 Silicates such as zeolite, barley stone, talc and montmorillonite; tungstates such as calcium tungstate; titanates such as barium titanate, potassium titanate and aluminum titanate), metal nitrides (silicon nitride, Boron nitride, aluminum nitride, titanium nitride, etc.), metal carbonization (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.). The inorganic filler may be in the form of fibers (for example, glass fiber, carbon fiber, metal fiber, whisker, etc.), but is preferably in the form of powder. Inorganic fillers are ferromagnetic materials, for example, ferromagnetic metals (powder) such as iron, cobalt and nickel; ferromagnetic alloys (powder) such as magnetite and ferrite; ferromagnetic metal oxides (powder) such as magnetic iron oxide, etc. It may be. These inorganic fillers can be used alone or in combination of two or more.

  In addition, the inorganic filler (inorganic filler) usually does not melt at the kneading temperature of the polymer when preparing the dispersion described later.

  The inorganic filler also includes a colorant, for example, a pigment [inorganic colorant (inorganic pigment)]. The colorant may be achromatic or chromatic (yellow, orange, red, purple, blue, green, etc.).

  The inorganic filler may have various functions such as ultraviolet absorptivity (or blocking property). Typical inorganic fillers include metal oxides (or metal oxide particles) such as titanium oxide and zinc oxide. The inorganic filler may be surface-treated with silica, alumina or the like. Such a surface treatment does not correspond to the hydrophobization treatment described later.

  Inorganic fillers are usually hydrophobized. When an inorganic filler that has been subjected to a hydrophobic treatment is used, the inorganic filler can be dispersed at a high concentration in the resin particles when a dispersion described below is prepared. The hydrophobic treatment can be performed by treating (or coating) the inorganic filler with a hydrophobic treatment agent. Examples of the hydrophobizing agent include surface treating agents that can make the inorganic filler more hydrophobic, for example, organometallic compounds such as organosilicon compounds and organotitanium compounds, depending on the type of the inorganic filler. The hydrophobizing agents may be used alone or in combination of two or more.

  Examples of the organosilicon compound include polysiloxane (polyorganosiloxane) and a silane coupling agent having a hydrophobic group.

Examples of the polysiloxane (polysiloxane having a hydrophobic group) include polydialkylsiloxanes (for example, polydiC _1-10 alkylsiloxanes such as polydimethylsiloxane and polyoctylmethylsiloxane), and polyalkylarylsiloxanes (for example, polymethylsiloxane). Poly C _1-10 alkyl C _6-20 aryl siloxane such as phenyl siloxane, preferably poly C _1-4 alkyl C _6-10 aryl siloxane), polydiaryl siloxane (eg, polydi C _6-20 aryl such as polydiphenyl siloxane) Siloxane), polyalkyl hydrogen siloxanes (eg, poly C _1-10 alkyl hydrogen siloxanes such as polymethyl hydrogen siloxane), organosiloxane copolymers (eg, dimethyl). Tylsiloxane-methylvinylsiloxane copolymer, dimethylsiloxane-methylphenylsiloxane copolymer, dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymer, dimethylsiloxane-methylhydrogensiloxane copolymer (dimethicone / methicone copolymer) Modified polysiloxane [modified polyorganosiloxane corresponding to the polyorganosiloxane, such as hydroxyl-modified polyorganosiloxane (eg, terminal silanol polydimethylsiloxane, terminal silanol polymethylphenylsiloxane, terminal hydroxypropyl polydimethylsiloxane, poly Dimethylhydroxyalkylene oxide methylsiloxane), amino-modified polyorganosiloxane (eg terminal dimethyl) Mino polydimethylsiloxane, terminal aminopropyl polydimethylsiloxane, etc.), carboxy-modified polysiloxanes (e.g., terminal carboxy propyl polydimethylsiloxane, etc.), etc.] and the like.

Among these, representative polyorganosiloxanes include polyorganosiloxanes (eg, polydimethylsiloxane (or dimethicone), dimethicone / methicone) containing at least polydimethylsiloxane (dimethicone) units or polymethylhydrogensiloxane (methicone) units. Polysiloxanes having hydrocarbon groups (eg, C _1-10 alkyl groups, preferably C _1-4 alkyl groups, etc.) such as copolymers, mixtures thereof, and the like.

  As the silane coupling agent having a hydrophobic group, a silane coupling agent having a hydrocarbon group, for example, an alkoxysilane having a hydrocarbon group (particularly, a hydrocarbon group directly bonded to a silicon atom), or a halosilane having a hydrocarbon group. (For example, chlorosilane having a hydrocarbon group). In the silane coupling agent, the hydrocarbon group may be partially or entirely substituted with a halogen atom (fluorine atom, chlorine atom, etc.), or a reactive group or functional group (for example, epoxy Group, (meth) acryloyl group, amino group, hydroxyl group, mercapto group, etc.).

As typical silane coupling agents, for example, alkoxysilane having an alkyl group {for example, alkylmonoalkoxysilane (for example, C _{1-24 alkylmonoalkoxysilane} such as octyldimethylmethoxysilane), alkyldialkoxysilane [for example, , dialkyl dialkoxy silanes (e.g., dimethyldimethoxysilane, dimethyldiethoxysilane, diethyl dimethoxysilane, di _{C 1-24} alkyl di _{C 1-4} alkoxysilane such as diethyl diethoxy silane, preferably di _{C 1-18} alkyl _{C 1 -4} alkoxysilane, more preferably diC _1-12 alkyl C _1-2 alkoxysilane etc.), cycloalkylalkyl dialkoxysilane (cyclohexylmethyldimethoxysilane etc.)], alkyltria Lucoxysilane (eg, methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, par perfluorooctyl triethoxysilane, 2-ethylhexyl trimethoxysilane, _{C 1-24} alkyl tri _{C 1-4} alkoxysilane such as decyl _{trimethoxysilane, C 1-18} alkyl tri _{C 1-4 alkoxysilane, C 1-12} alkyl alkyl mono- or alkoxysilanes such as such as tri C _1-2 alkoxy silane); alkoxysilane having an amino group (e.g., 3-aminopropyl methyl dimethoxysilane, 3-amino Propyl methyl diethoxy silane, 2-aminoethyl trimethoxy silane, aminoalkyl mono- to tri-alkoxysilanes such as 3-aminopropyltriethoxysilane, preferably an amino C _2-10 alkyl mono- to tri-C _1-4 alkoxysilane, further Preferably, amino C _2-6 alkyl mono to tri C _1-2 alkoxysilane), alkoxysilane having a mercaptoalkyl group (for example, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrimethyl). mercapto _{C 2-10} alkyl mono- to _{tri-C 1-4} alkoxysilanes such as ethoxysilane), (alkoxysilane having an meth) acryloyloxy alkyl group (e.g., 2- (meth) acryloxyethyl Trimethoxysilane, 3- (meth) acryloxy propyl triethoxysilane (meth) acryloyloxy C _2-10 alkyl mono- to tri-C _1-4 alkoxysilane, etc.), alkoxysilane having the glycidyloxy alkyl group (e.g., 3 -Glycidyloxypropylmethyldimethoxysilane, 2-glycidyloxyethyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, and other reactive groups such as glycidyloxy C _2-10 alkyl mono to tri C _1-4 alkoxysilane) substituted mono- or trialkoxysilane having an alkyl group}, C _2-4 alkenyl C _1-4 alkyl di C _1-4 alkoxysilane such as alkoxysilane {e.g., vinyldimethoxymethylsilane having an alkenyl group; divinyl Alkoxysilane having vinyltrimethoxysilane, etc. _{C 2-4} Arukenirutori _{C 1-4} alkoxysilane such as vinyltriethoxysilane}, an aryl group, di _{C 2-4} Arukeniruji _{C 1-4} alkoxysilane such as dimethoxysilane {for example, diaryl dialkoxy silanes (e.g., diphenyl dimethoxysilane, and di-C _6-10 aryldi C _1-4 alkoxysilane such as diphenyl diethoxy silane), aryl trialkoxysilane (e.g., C _6, such as phenyl trimethoxysilane _-10 Arirutori C _1-4 alkoxysilane, etc.) alkoxysilane (mono- or trialkoxysilane having a hydrocarbon group, etc.); halosilane having a hydrocarbon group (e.g., trimethylchlorosilane, dimethyldichlorosilane, Chill trichlorosilane, halosilane corresponding to these alkoxysilanes, such as n- octyl dimethyl chlorosilane), and the like.

The organic titanium compounds, the titanium compounds corresponding to the organic silicon compound, for example, for example, alkoxy titanium {e.g. having a hydrocarbon group, Jiarukiruji C _1-4 alkoxy titanates (diethyl diethoxy titanate, etc.), alkyl tri C _{1- 4-} alkoxy titanate (such as ethyl trimethoxy titanate), aryl tri C _1-4 alkoxy titanate (such as phenyl trimethoxy titanate)] and the like.

Of these hydrophobizing agents, organosilicon compounds such as polyorganosiloxanes (polysiloxanes having hydrocarbon groups) and silane coupling agents having hydrocarbon groups are preferred, and in particular alkoxysilanes having hydrocarbon groups {for example Alkyl alkoxysilanes (eg C _1-24 alkyl mono to trialkoxy silanes, preferably C _1-18 alkyl mono to tri C _1-4 alkoxy silanes, more preferably C _1-12 alkyl mono to tri C _1-2). An alkoxysilane having an alkyl group such as an aminoalkylalkoxysilane}.

Among silane coupling agents having a hydrocarbon group, a silane coupling agent having a hydrocarbon group having a relatively large carbon number (for example, an alkyl group having 4 or more carbon atoms), for example, having an alkyl group having 4 or more carbon atoms. Alkoxysilanes (eg C _4-24 alkyl mono to trialkoxy silanes, preferably C _4-18 alkyl mono to tri C _1-4 alkoxy silanes, more preferably C _6-12 alkyl mono to tri C _1-2 alkoxy silanes. Etc.) is preferable. Moreover, it is more preferable that the silane coupling agent having a hydrocarbon group does not have a hydrophilic functional group (such as an amino group or a mercapto group) in the hydrocarbon group. When such a silane coupling agent is used, a high concentration inorganic filler can be more reliably included in the resin particles.

  The ratio of the hydrophobizing agent to the whole inorganic filler is, for example, 0.1 to 15% by weight (for example, 0.3 to 12% by weight), preferably 0.5 to 10% by weight (for example, 0.7 to 8%). % By weight), more preferably about 1 to 7% by weight (for example, 1.5 to 5% by weight).

[Resin particles]
As described above, the resin particles (composite resin particles) of the present invention contain an inorganic filler at a very high concentration. The ratio of the inorganic filler in the resin particles can be selected from a range of 40% by weight or more (for example, about 45 to 95% by weight), for example, 45 to 90% by weight, preferably 50 to 85% with respect to the entire resin particles. % By weight, more preferably 55-80% by weight, usually about 50-80% by weight (for example, 52-75% by weight, preferably 55-70% by weight, more preferably 58-65% by weight). Also good.

  The shape of the resin particles is particularly preferably spherical (or true spherical). In the present invention, spherical resin particles can be obtained efficiently by using the dispersion described later.

  In addition, in the resin particles, the inorganic filler is usually required to be included in the form of being encapsulated in the resin particles, and a part of the inorganic filler covers (or is exposed or attached to the surface) the resin particle surface. It may be contained in the resin particles. Since the resin particles of the present invention include the inorganic filler in the resin particles as described above, the particle surface may be relatively smooth. The smoothness (or unevenness) of the surface of the resin particles is based on the surface area SAc per 1 g of the particle calculated from the average particle diameter assuming that the resin particle is a true sphere, and per 1 g of the resin particle measured by the nitrogen adsorption method. The specific surface area SAt can be evaluated. That is, when the ratio of the specific surface area SAt to the surface area SAc (SAt / SAc) increases, the specific surface area increases due to the irregular shape of the particle surface caused by the inorganic filler present on the surface. The resin particles of the present invention have such SAt / SAc values of 1 to 4, preferably 1 to 3.5, more preferably 1 to 3.3 (for example, 1 to 3), particularly 1 to 2. It may be about 5.

  The volume average particle diameter (Dw) of the resin particles of the present invention can be appropriately selected depending on the application, but can be selected, for example, from a range of about 0.3 to 100 μm (for example, 0.4 to 80 μm), preferably 0. It may be about 5 to 60 μm (for example, 1 to 50 μm), more preferably about 1.5 to 30 μm. The volume average particle diameter (Dw) of the composite resin particles is usually about 1 to 80 μm (for example, 3 to 50 μm), and depending on applications, 20 to 70 μm, preferably about 30 to 60 μm (for example, 30 to 50 μm). It may be appropriate.

  In the 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 to. It may be about 4.

  The resin particles of the present invention are not particularly limited, but usually, the resin particles (resin particles containing inorganic filler in a proportion of 40% by weight or more) as a dispersed phase are dispersed in a continuous phase composed of an auxiliary agent. It is obtained by removing (eluting) the auxiliary from the dispersion. Therefore, the present invention includes such a dispersion (and a method for producing the resin particles by eluting the auxiliary from the dispersion). Hereinafter, the dispersion (a dispersion having resin particles as a dispersed phase) will be described in detail.

[Method for producing dispersion and resin particles]
The dispersion is composed of an auxiliary agent (specifically, an auxiliary agent incompatible with the polymer) and the resin particles dispersed in the auxiliary agent. That is, the dispersion is composed of the resin particles as a dispersed phase (or dispersed phase particles) and the auxiliary as a continuous phase (or matrix).

(Auxiliary)
As the auxiliary, a water-soluble auxiliary can be usually used. When a water-soluble auxiliary agent 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 water-soluble and 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 saponified product 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. Among these, the auxiliary agent is selected from water-soluble polysaccharides, in particular, oligosaccharides and water-soluble polysaccharides having at least one cyclic structure (sometimes referred to as polysaccharides having a cyclic structure, cyclic polysaccharides, etc.). Further, it is preferably composed of at least one water-soluble polysaccharide, and both may be used in combination. By using the water-soluble polysaccharide, the melt viscosity can be easily adjusted, and the inorganic particles can be efficiently encapsulated in the resin particles. Further, the particle diameter of the resin particles can be controlled efficiently. And when such a water-soluble polysaccharide is used, when the dispersion is eluted or washed to obtain resin particles, the solution viscosity of the auxiliary agent dissolved in the solvent does not increase, and the 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 and maltose; and hetero-oligosaccharides such as lactose, sucrose, and palatinose. Trisaccharides include homo-oligosaccharides such as maltotriose; hetero-oligosaccharides such as manninotriose and soratriose. As tetrasaccharides, homo-oligosaccharides such as maltotetraose; sugars or sugar alcohols (monosaccharides such as glucose, fructose, mannose, xylose, arabinose, sorbitol, xylitol, erythritol, etc.) bound to the reducing end of panose, etc. And other hetero-oligosaccharides. Examples of pentasaccharides include homo-oligosaccharides such as maltopentaose; hetero-oligosaccharides such as pentaose in which disaccharides (sucrose, lactose, cellobiose, trehalose, etc.) are bound to the reducing end of panose. 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).

  The oligosaccharide composition may contain a large number of relatively large multimeric oligosaccharides. For example, in the oligosaccharide composition, the content ratio of the oligosaccharides more than the decasaccharide is 20 wt% or more (for example, 25 To 100% by weight), preferably 30% by weight or more (for example, 35 to 90% by weight), more preferably 40% by weight or more (for example, 45 to 80% by weight), especially about 50 to 70% by weight. It may be about 40 to 75% by weight.

  The oligosaccharide may be a non-reducing type, but a reducing type (maltose type) oligosaccharide is preferable because of its excellent heat resistance. The reduced oligosaccharide is not particularly limited as long as it is a sugar having a free aldehyde group or a ketone group and exhibiting reducibility.

  In order to effectively disperse the polymer and the auxiliary agent by melt mixing, 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 heat distortion temperature of the polymer is, for example, 1 ° C. or higher (for example, about 1 to 80 ° C.), preferably 10 ° C. or higher (for example, about 10 to 70 ° C.). More preferably, it is 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 polymer, for example, 90 to 290 ° C., preferably 100 to 280 ° C. (eg 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.

  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.

  Water-soluble polysaccharides having a cyclic structure have a higher melt viscosity than oligosaccharides, and are water-soluble because of their 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 may 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 Examples thereof include polysaccharides having a degree of polymerization of 50 or more, polysaccharides having one cyclic structure formed of 14 or more α-1,4-glucoside bonds in the molecule, and the like.

  For details of the water-soluble polysaccharide having a cyclic structure, JP-A No. 2007-119674 can be referred to.

  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. 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 heat distortion temperature of the polymer (the Vicat softening point).

  The water-soluble plasticizing component may be composed of saccharides, sugar alcohols, etc., and such saccharides may be composed of reducing sugars. The water-soluble plasticizing component may in particular be a sugar alcohol. 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 includes at least one sugar alcohol selected from erythritol, pentaerythritol, sorbitol, and xylitol.

  In the auxiliary agent, the ratio of the water-soluble polysaccharide and the plasticizing component is the former / the latter (weight ratio) = 99 / 1-20 / 80, preferably 97 / 3-30 / 70, more preferably 95/5. About 40/60 may be sufficient and about 95 / 5-50 / 50 (for example, 93 / 7-60 / 40) may be sufficient. 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.

  In the dispersion, the ratio of the resin particles to the auxiliary agent is, for example, the former / the latter (volume ratio) = 5/95 to 50/50, preferably 10/90 to 40/60, more preferably 15/85. About 35/65.

(Method for producing dispersion)
The dispersion of the present invention can be usually produced by melt-kneading (or melt-mixing) the inorganic filler, the polymer, and the auxiliary agent (and other components as required). That is, the method for producing the resin particles usually involves melt-kneading (or melt-mixing) the inorganic filler, the polymer, and the auxiliary agent (and other components as necessary) to obtain a dispersion. The manufacturing process is included. In addition, even if an inorganic filler is mixed at a high concentration by using a hydrophobic treated inorganic filler as described above, the inorganic filler can be efficiently distributed to the dispersed phase, and the high concentration of the present invention Thus, resin particles containing an inorganic filler can be obtained.

  In the melt-kneading, the inorganic filler may be melt-mixed with the polymer individually (or individually or independently), or may be preliminarily contained in the polymer. That is, the step of producing the dispersion includes (1) a step of producing a dispersion by melting and mixing (simultaneously or simultaneously or together) an inorganic filler, a polymer, and a water-soluble auxiliary agent, or ( 2) In any of the steps of melt-mixing a melt mixture of an inorganic filler and a polymer (that is, a melt mixture obtained by previously melt-mixing an inorganic filler and a polymer) and a water-soluble auxiliary agent. Good. In the step (2), a part of the inorganic filler may be melt-mixed with the polymer, or the whole may be melt-mixed with the polymer in advance.

  In the preparation of the dispersion, when a polymer (polymer composition) containing an inorganic filler in advance is used as in step (2), the inorganic filler may be efficiently contained in the resin particles. In particular, such a method is effective for obtaining resin particles containing an inorganic filler at a high concentration (and having a relatively large particle size) as in the present invention. However, when the inorganic filler and the polymer are previously melt-mixed, the manufacturing process of the dispersion becomes complicated. In the present invention, by using the inorganic filler subjected to the hydrophobization treatment as described above, the inorganic filler and the high filler can be obtained by the step (1), that is, without preparing a molten mixture of the inorganic filler and the polymer in advance. Even if a dispersion is prepared by simultaneously melting and mixing molecules and a water-soluble auxiliary agent, resin particles containing an inorganic filler at a high concentration can be obtained efficiently.

  In the production of the dispersion, the ratio of each component used (such as the ratio of the inorganic filler) is the same as described above. In the present invention, the inorganic filler can be contained (encapsulated) in the resin particles while suppressing or preventing the inorganic filler from being distributed to the continuous phase composed of the auxiliary agent at a very high level. The ratio of each component (for example, inorganic filler) used can be accurately reflected in the resin particles. In either case of steps (1) and (2), a mixing process in a non-molten state may be performed prior to melt mixing. That is, the manufacturing method further includes a step of mixing (dry mixing) the inorganic filler and the polymer without melting (or in a non-molten state) prior to melt mixing in the step (1) or (2). May be included. For example, in the step (1), after mixing (dispersing) the inorganic filler and the polymer without melting the polymer, the obtained mixture and the water-soluble auxiliary agent may be melt-mixed. In step (2), the inorganic filler and the polymer are mixed (dispersed) without melting, and then the mixture is melted to prepare a molten mixture. The molten mixture, the water-soluble auxiliary agent, May be melt mixed. The combination of such a non-molten mixing process (dispersion process) with the step (1) or (2) may cause the polymer to act as a pulverization medium for the inorganic filler, or resin particles of the inorganic filler. The uniform dispersibility inside can be further improved. In the case of dry blending, the polymer shape is preferably granular or pelleted from the viewpoint of preventing aggregation of the inorganic filler.

  Melt mixing (including the case where the inorganic filler and polymer are previously melt-mixed in step (2)) is a conventional kneader (for example, a single or twin screw extruder, kneader, calender roll, Banbury mixer, Lavender 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.

  In addition, when melt-mixing an inorganic filler and a polymer in advance, the shape of the resulting melt mixture (melt mixture to be used for melt-mixing with an auxiliary agent) is not particularly limited, and may be in the form of powder, pellets, etc. Good. The melt mixing temperature (kneading temperature, molding temperature) can be appropriately set according to the raw materials used, and is, for example, 90 to 300 ° C., preferably 110 to 270 ° C. (for example, 130 to 260). ° C), more preferably about 140 to 250 ° C (for example, 150 to 240 ° C). In order to avoid thermal decomposition of auxiliaries (for example, oligosaccharides and plasticizing components), the melt mixing temperature may be 250 ° C. or lower (for example, about 160 to 240 ° C.). The melt mixing 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). Furthermore, in the melt mixing, the mixing rotation speed (kneading rotation speed) may be, for example, about 5 to 300 rpm, preferably about 10 to 250 rpm, more preferably about 20 to 200 rpm, and particularly about 30 to 150 rpm. In the step (2), when the inorganic filler and the polymer are previously melt-mixed, they can be melt-mixed under the same conditions as described above.

  The molten mixture (dispersion) may be in the form of a lump or the like, and may be subjected to molding (preliminary molding) from the viewpoint of removing the matrix component (that is, the auxiliary agent) to form a preformed body. . 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).

  The dispersion of the present invention is prepared as described above. Such a dispersion contains the resin particles as a dispersed phase, and the resin particles contain an inorganic filler at a high concentration as described above.

  Furthermore, the resin particles are obtained by eluting the auxiliary from the dispersion obtained as described above. That is, resin particles are obtained by elution treatment of the dispersion with a solvent that dissolves the auxiliary.

  The solvent may be any solvent that dissolves the auxiliary and is insoluble (not soluble) in the resin particles, and a suitable solvent is water.

  When a water-soluble auxiliary agent (water-soluble sugar composition) is used, the auxiliary agent can be easily dissolved with water to separate the composite resin particles and the auxiliary agent, and the viscosity of the extract solution in which the auxiliary agent is dissolved is reduced. It can be prevented from becoming 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 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 resin particles can usually be recovered from the dispersion containing the resin particles after the elution treatment. In the elution treatment, the auxiliary may be discharged as a solution of the solvent leaving only the resin particles, the dispersion is eluted or washed with a solvent, the auxiliary is dissolved, and the composite resin particles are It is useful to produce and recover a dispersed dispersion or extract.

  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 reference examples, the following thermoplastic resins, inorganic fillers and auxiliaries were used.

(Thermoplastic resin A)
(A1) Polyamide (Polyamide 12, manufactured by Daicel Evonik Co., Ltd., “Z9004”)
(A2) Polyester (polybutylene terephthalate-polycaprolactone block copolymer, manufactured by Toyobo Co., Ltd., “Perprene S1002”)
(A3) Cycloolefin copolymer (manufactured by Ticona, cyclic polyolefin polymer TOPAS (registered trademark) 5013S-04)
(A4) Polymethyl methacrylate (manufactured by Asahi Kasei Chemicals Corporation, Delpet 720V)
(A5) Polyethylene (LLDPE, manufactured by Nippon Unicar Co., Ltd., “NUCG-5301”)
(A6) Polystyrene (Toyo Styrene Co., Ltd., G100C).

(Inorganic filler B)
(B1) Titanium oxide particles 1 (manufactured by Ishihara Sangyo Co., Ltd., “Taipeku CR-60”, alumina surface-treated product, average primary particle size 210 nm, specific surface area 10 m ² / g)
(B2) Titanium oxide particles 2 (manufactured by Ishihara Sangyo Co., Ltd., “Taipeku CR-63”, alumina, silica, siloxane surface treatment product, average primary particle size 210 nm)
(B3) Titanium oxide particles 3 (commercially available titanium oxide particles, titanium oxide obtained by surface-treating “Taipec CR-60” manufactured by Ishihara Sangyo Co., Ltd. with 3-aminopropyltriethoxysilane, average primary particle size 210 nm)
The titanium oxide particles 3 were prepared by using 2.83 parts by weight of 3-aminopropyltriethoxysilane with respect to 100 parts by weight of “Taipaque CR-60” using a rotating / revolving mixer (Shinky Co., Ltd., Nertaro Awatori). Prepared by mixing both components for 3 minutes in proportion. In addition, 3-aminopropyltriethoxysilane was used by calculating an amount sufficient for the surface treatment from the specific surface area of the titanium oxide particles and the minimum covering area of 3-aminopropyltriethoxysilane.

(B4) Titanium oxide particles 4 (commercially available titanium oxide particles, titanium oxide obtained by surface-treating “Taipek CR-60” manufactured by Ishihara Sangyo Co., Ltd. with n-octyltriethoxysilane, average primary particle size 210 nm)
Titanium oxide particles 4 were prepared by using a rotating / revolving mixer (manufactured by Shinky Co., Ltd., Kentaro Awatori), and a ratio of 3.53 parts by weight of n-octyltriethoxysilane to 100 parts by weight of “Taipaque CR-60”. And prepared by mixing both components for 3 minutes. It should be noted that n-octyltriethoxysilane was used by calculating an amount sufficient for surface treatment from the specific surface area of the titanium oxide particles and the minimum coating area of n-octyltriethoxysilane.

(B5) Titanium oxide particles 5 (commercially available titanium oxide particles, titanium oxide obtained by surface-treating “Taipec CR-58” (specific surface area 16 m ² / g) manufactured by Ishihara Sangyo Co., Ltd. with 3-aminopropyltriethoxysilane, average Primary particle size 280nm)
The titanium oxide particles 5 were prepared using 4.53 parts by weight of 3-aminopropyltriethoxysilane with respect to 100 parts by weight of “Taipaque CR-58” using a rotating / revolving mixer (Shinky Co., Ltd., Nertaro Awatori). Prepared by mixing both components for 3 minutes in proportion.

(B6) Silica particles 1 (commercially available amorphous silica particles, silica particles obtained by surface-treating “Seahoster KE-P30” (specific surface area 50 m ² / g) manufactured by Nippon Shokubai Co., Ltd. with 3-aminopropyltriethoxysilane, average primary Particle size 0.30μm)
Silica particle 1 is a ratio of 5.00 parts by weight of 3-aminopropyltriethoxysilane to 100 parts by weight of “Seahoster KE-P30” using a rotating / revolving mixer (manufactured by Shinky Co., Ltd., Kentaro Awatori). And prepared by mixing both components for 3 minutes.

(Auxiliary agent C)
(C1) oligosaccharide (starch sugar, manufactured by Mitsubishi Corporation Foodtech Co., Ltd., reduced starch saccharified product “PO-10”)
(C2) Sugar alcohol (sorbitol, manufactured by Mitsubishi Shoji Foodtech Co., Ltd., “sorbitol LTSP20M”).

(Examples 1-4, Examples 9-10, Reference Examples 1-3)
40 parts by weight of a pellet-shaped thermoplastic resin shown in Table 1 and 60 parts by weight of an inorganic filler (titanium oxide particles or silica particles) are mixed for 3 minutes using a rotating / revolving mixer (Shinky Co., Ltd., Aritori Nertaro). After premixing, a thermoplastic resin composition containing an inorganic filler is melt-kneaded by Brabender (Toyo Seiki Co., Ltd., Labo Plast Mill) at a rotational speed of 100 rpm and a kneading time of 10 minutes at the temperature shown in Table 1. Lump) was prepared and cut into small pieces.

  Then, the thermoplastic resin composition cut into small pieces and a water-soluble auxiliary agent containing oligosaccharide and sugar alcohol at the ratio shown in Table 1 are blended at the ratio of the former / the latter (volume ratio) = 30/100 by Brabender ( A dispersion was obtained by melt kneading at a temperature shown in Table 1 at a rotational speed of 50 rpm and a kneading time of 10 minutes using a Toyo Seiki Co., Ltd. product (Laboplast Mill).

  The obtained dispersion was immersed in water at 25 ° C. to obtain a suspension of resin particles (composite resin particles). Using a membrane membrane (pore size 0.45 μm, made of cellulose acetate), insoluble matter was filtered off from the suspension 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 diameter 0.45 μm, made of cellulose acetate), insolubles were filtered off from the suspension to recover composite resin particles.

(Examples 5-8, Reference Examples 4-6)
40 parts by weight of the pellet-shaped thermoplastic resin shown in Table 1 and 60 parts by weight of an inorganic filler (titanium oxide particles) are premixed for 3 minutes using a rotating / revolving mixer (Shinky Co., Ltd., Aritori Kentaro). The thermoplastic resin / titanium oxide particle mixture obtained in this manner and a water-soluble auxiliary agent containing oligosaccharides and sugar alcohols in the ratios shown in Table 1 were blended at a ratio of the former / the latter (volume ratio) = 30/100. Using a lavender (Toyo Seiki Co., Ltd., Labo Plast Mill), the mixture was melt-kneaded at a rotation speed of 50 rpm, a kneading time of 10 minutes, and the temperature shown in Table 1 to obtain a dispersion.

  The obtained dispersion was immersed in water at 25 ° C. to obtain a suspension of resin particles (composite resin particles). Using a membrane membrane (pore size 0.45 μm, made of cellulose acetate), insoluble matter was filtered off from the suspension 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 diameter 0.45 μm, made of cellulose acetate), insolubles were filtered off from the suspension to recover composite resin particles.

[Measurement and evaluation of characteristics]
Various characteristics of the composite resin particles (or dispersions) obtained in the examples and comparative examples were measured and evaluated. The results are shown in Table 1. Measurement and evaluation were performed as follows.

(Particle size)
The obtained composite resin particles were observed with a scanning electron microscope (manufactured by JEOL Ltd., FE-SEM, JSM-6700F) to obtain photographs of the surface shape and the overall shape. Then, using the obtained scanning electron micrograph, draw a rectangle of an arbitrary size so that at least 200 particles are included on the photograph, and the particle diameter at the time of true sphere conversion of all particles present in the rectangle Measured. From the obtained particle diameters of at least 200, a volume average particle diameter (Dn) and a number average particle diameter (Dw) were obtained.

(shape)
The composite resin particles were observed with a scanning electron microscope (manufactured by JEOL Ltd., FE-SEM, JSM-6700F) to obtain photographs of the surface shape and the overall shape. From the obtained scanning electron micrograph, the shapes of the obtained composite resin particles were classified according to the following criteria.
1: Spherical 2: Non-spherical, but generally spherical 3: Non-spherical 4: Not particulate. In this case, when the dispersion was immersed in water, it did not become a suspension.

  For reference, electron micrographs of the composite resin particles obtained in Example 1, Example 2, and Example 6 among the electron micrographs are shown in FIGS.

(position)
The fracture surface obtained by cutting out the dispersion (a melt-kneaded product of polymer, inorganic filler and auxiliary agent) was observed with a scanning electron microscope (FE-SEM, JSM-6700F, manufactured by JEOL Ltd.), and the dispersion was broken. A photograph of the cross-sectional shape was obtained. From the obtained scanning electron micrograph, since the inorganic filler (titanium oxide or silica) shines white, the dispersion state of the inorganic filler in the dispersion can be easily observed. Therefore, the position of the inorganic filler was confirmed from the obtained scanning electron micrograph, and the position of the inorganic filler in the dispersion was classified according to the following criteria.
◎: All distributed to polymer ○: Almost distributed to polymer, but distributed a little to auxiliary side Δ: Distributed to auxiliary side ×: Mostly distributed to auxiliary side Distributing.

  For reference, among the electron micrographs, electron micrographs of fracture surfaces of the dispersions obtained in Reference Example 1, Example 1, Example 2, Reference Example 4, Reference Example 5 and Example 6 were respectively shown. Shown in FIGS.

(Contained state)
The composite resin particles were mixed with an epoxy resin adhesive (manufactured by Konishi Co., Ltd., “Bond Quick 5”) to prepare a lump in which the resin particles were dispersed in the epoxy polymer adhesive. A cross-section obtained by cutting the obtained lump with a microtome was observed with a scanning electron microscope (manufactured by JEOL Ltd., FE-SEM, JSM-6700F) to obtain a photograph of the cross-sectional shape of the lump. From the obtained scanning electron micrograph, since the inorganic filler (titanium oxide or silica) shines white, the dispersion state of the inorganic filler inside the resin particles can be easily observed. Therefore, the dispersion state of the inorganic filler in the composite resin particles was confirmed from the obtained scanning electron micrograph, and the structure (contained state) of the inorganic filler in the resin particles was classified according to the following criteria.
◎: Encapsulated in resin particles and large in quantity ○: Some of them are covered with resin particles, but included in resin particles Δ: Covered with resin particles X: Almost no in resin particles. In this case, it is considered that the particles were distributed to the auxiliary agent in the process of particle formation.

  For reference, among the electron micrographs, the electron micrographs of the cross sections of the composite resin particles obtained in Reference Example 1, Example 1, Example 2, Reference Example 4, Reference Example 5 and Example 6, respectively. Shown in FIGS.

(Content ratio)
1 g of resin particles was placed in a platinum container and heated at 900 ° C. for 5 hours to quantify the amount of metal remaining as ash. Then, using this determined amount of metal and the weight ratio of metal atoms contained in the used inorganic filler (titanium oxide particles or silica particles), the amount of inorganic filler contained in the resin particles according to the following formula (% by weight) Was calculated.

  (Residual metal amount × molecular weight of inorganic filler / mass of metal atom (titanium atom or silicon atom) in 1 mol of inorganic filler) × 100

  The resin particles of the present invention can be 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 molded products), spacers (liquid crystal panel spacers, etc.), carriers, base particles of secondary processed particles such as conductive particles, cosmetic materials, compression molding, laser molding, etc. Can be suitably used as a raw material for molding processing using the above powder, a light scattering additive (light diffusing agent) for flat panel displays and the like. In particular, the resin particles of the present invention can be used as polymer pigments, various electromagnetic wave absorbing materials, display members for electronic paper, etc. that require high concealment because the particle size and concentration of the inorganic filler can be increased.

Claims (11)

  Resin particles containing an inorganic filler in a proportion of 40% by weight or more.   The resin particle according to claim 1, wherein the inorganic filler is an inorganic filler hydrophobized with an organosilicon compound.   The resin particle according to claim 1 or 2, wherein the inorganic filler is an inorganic filler hydrophobized with at least one selected from polysiloxane and a silane coupling agent having a hydrophobic group.   The resin particles according to any one of claims 1 to 3, wherein the inorganic filler has an average primary particle size of 100 to 800 nm.   The inorganic filler is an inorganic filler hydrophobized with an alkoxysilane having a hydrocarbon group, the average particle diameter of the inorganic filler is 150 to 500 nm, and the inorganic filler is contained in a proportion of 50 to 80% by weight. Item 5. The resin particle according to any one of Items 1 to 4.   The resin particle according to claim 5, wherein the inorganic filler is an inorganic filler hydrophobized with an alkoxysilane having an alkyl group having 4 or more carbon atoms.   The dispersion which the resin particle in any one of Claims 1-6 disperse | distributed to the continuous phase comprised with the water-soluble auxiliary agent.   A method for producing a resin particle according to any one of claims 1 to 6, wherein a continuous phase is eluted from the dispersion according to claim 7. The manufacturing method of Claim 8 including the process of preparing a dispersion by the following processes (1) or processes (2).
(1) Step of preparing a dispersion by melting and mixing an inorganic filler, a polymer, and a water-soluble auxiliary agent (2) Melting and dispersing a molten mixture of an inorganic filler and a polymer and a water-soluble auxiliary agent The process of preparing the body   The method according to claim 9, further comprising a step of mixing the inorganic filler and the polymer without melting them prior to melt mixing in the step (1) or (2).   The manufacturing method according to claim 9, wherein an inorganic filler that is hydrophobized with an organosilicon compound and has an average primary particle size of 100 nm or more is used as the inorganic filler, and the dispersion is prepared by the step (1).