WO2004076560A1

WO2004076560A1 - Thermoplastic resin composition

Info

Publication number: WO2004076560A1
Application number: PCT/JP2003/002168
Authority: WO
Inventors: Haruhiko Furukawa; Yoshitsugu Morita; Hiroshi Ueki; Koji Shiromoto
Original assignee: Dow Corning Toray Silicone Co Ltd
Current assignee: DuPont Toray Specialty Materials KK
Priority date: 2003-02-26
Filing date: 2003-02-26
Publication date: 2004-09-10
Anticipated expiration: 2005-08-26
Also published as: AU2003208617A1

Abstract

Thermplastic resin composition comprising (A) a thermoplasitc resin, (B) a vinyl-type polymer having at least one silicon-bonded hydrogen atoms, particularly a radical-polymerization product of (a) a vinyl monomer and (b) a vinyl-type monomer having at least one silicon-bonded hydrogen atoms, and (C) inorganic powder. Component (B) allows for the combination of component (C) with component (A) without decreasing the molecular weight of component (A) and without imparing composition's color tone. The thermoplastic resin composition possesses excellent thermal stability and moldability and, after molding, produces molded articles with improved mechanical strength and color tone.

Description

DESCRIPTION

THERMOPLASTIC RESIN COMPOSITION

[0001] The present invention provides a thermoplastic resin composition comprising a thermoplastic resin, a vinyl-type polymer having at least one silicon-bonded hydrogen atoms in its molecule, and an inorganic powder. The present composition has high thermal stability and moldability and molded products prepared therefrom have improved mechanical strength and color tone.

[0002] Polycarbonate resins, polypropylene resins, polystyrene resins, ABS resins or other similar thermoplastic resins are known as engineering plastics which are often used in the manufacture of electronic devices, electric appliances, automotives, building materials, construction materials, and other products. The mechanical strength or color tones of such resins can be improved by combining them with various inorganic powder materials.

[0003] However, the addition of aforementioned inorganic powders typically decreases the thermal resistance of thermoplastic resins. For example, a polycarbonate resin is often combined with a titanium oxide, which is a typical white pigment. However, this white pigment decreases the polycarbonate's molecular weight. Subsequently, the mechanical strength of the polycarbonate is diminished resulting in a decline of thermal stability and deterioration of color tone. Similarly, the addition of a titanium oxide to polypropylene resins, high-impact polystyrene resins, ABS resins, or similar organic resins, decreases either flowability and moldability, or mechanical strength of these resins. It has been known heretofore to solve the above problems by adding to polycarbonate resin compositions containing a titanium oxide a dimethylpolysiloxane having 3-trimethoxysilylpropyl groups in its side molecular chain as taught, for example, in Japanese Patent Application Publication (Kokai) No. H6-200140. However, the effects of such treatments are limited and a need still exists to identify thermoplastic compositions having improved mechanical strengths and retention of color tones.

[0004] The present inventors have discovered the addition of a specific vinyl-type polymer to thermoplastic resin compositions containing inorganic powders results in compositions having excellent thermal stability and moldability. It is an object of the present invention to provide to allow for the combination of an inorganic powder with a thermoplastic resin without decreasing the molecular weight of the thermoplastic resin and without impairing the resin's color tone. Still another object is to provide a thermoplastic resin composition which possesses excellent thermal stability and moldability and which, after molding, produces molded articles with high mechanical strength and attractive color tone.

[0005] The present invention relates to a thermoplastic resin composition comprising:

(A) 100 parts by weight of a thermoplastic resin;

(B) 0.01 to 50 parts by weight of a vinyl-type polymer having at least one silicon- bonded hydrogen atoms in its molecule; and

(C) 0.01 to 200 parts by weight of an inorganic powder.

[0006] Thermoplastic resin (A) is a moldable component with thermoplastic properties. Component (A) can be any organic resin selected from commonly known "thermoplastic resins" or "thermoplastic elastomers". The following are specific, representative examples of such thermoplastic resins: polyethylene (PE) resins such as low-density polyethylene (LDPE) resin, medium-density polyethylene resin, high-density polyethylene (HDPE) resin, and ultra- high-molecular- weight polyethylene (UHMPE) resin; copolymers of ethylene and propylene, as well as butene-1, pentene-1, hexane-l,4-methylpentene-l, octane-1, decene-1, or of a similar olefin with 4 to 12 carbon atoms; a polypropylene (PP) resin; copolymers of propylene and butene-1, as well as pentene-1, hexane-l,4-methylpentene-l, octane-1, decene- 1, or a similar olefin with 4 to 12 carbon atoms; an ethylene-propylene-diene copolymer; polymethylpentene resin (MPX); a copolymer of ethylene and a methacrylic acid ester; copolymers of ethylene and vinyl acetate, as well as maleic acid, or anhydrous maleic acid; a polymethyl methacrylate (PMMA) resin, or a similar acryl-type resin; polystyrene (PS) resin, high-impact polystyrene (HIPS) resin, a copolymer of acrylonitrile, butadiene, and styrene (ABS), a copolymer of acrylonitrile and styrene (AS), a copolymer of acrylonitrile, acryl rubber, and styrene (AAS), a copolymer of acrylonitrile, ethylenepropylene rubber, and styrene (AES), or a similar polystyrene-type resin; polyvinylacetate resin, polyvinylchloride (PVC) resin, polyvinylidene chloride (PVDC) resin, polyvinyl alcohol (PVA) resin, polytetrafluoroethylene resin (PTFE) or another vinyl-type resin; polybutylene-terephthalate (PBT) resin, polyethylelene-terephthalate (PET) resin, or a similar polyester resin; Nylon 6, Nylon 66, Nylon 610, Nylon 11, Nylon 12, or a similar polyamide resin; polyacetal (POM) resin, or a similar polyoxyalkylene resin; a polycarbonate (PC) resin such as an aromatic polycarbonate resin; modified polyphenylene ether (modified PPE) resins; polyvinyl acetate (PVAC) resin; polysulfone (PSU) resin; polyethersulfone (PES) resin, polyphenylene sulfide (PPS) resin, or a similar polysulfide-type resin; polyarylate resin; a polyamidoimide (PAI) resin; polyetherimide (PEI) resin; polyetheretherketone (PEEK) resin; polyimide (PI) resin; liquid crystal polyester (LCP) resin, or copolymers of the above. Other examples includes resins known as thermoplastic elastomers, such as polystyrene-type thermoplastic elastomer, polyolefin-type thermoplastic elastomer, polyester-type thermoplastic elastomer, polyurethane-type thermoplastic elastomer, polyamide-type thermoplastic elastomer, polyfluoro-type thermoplastic elastomer, polyvinylchloride-rype thermoplastic elastomer, or the like. Most preferable among the above are the polycarbonate-type resin such as aromatic polycarbonate resin, polyolefin-type resin such as polyethylene resin, polypropylene resin, and ethylene-propylene copolymer resin, and polystyrene-type resin such as polystyrene resin, high-impact polystyrene resin and ABS resin.

[0007] Component (B) is a vinyl-type polymer having at least one silicon-bonded hydrogen atoms in its molecule. This component facilitates uniform dispersion of component (C) in component (A) and at the same time prevents deterioration of component (A) by component (C). Component (B) contains in its molecule at least one silicon-bonded hydrogen atoms. Typically, the silicon-bonded hydrogen atom exists in a side molecular chain or side molecular chains of a vinyl-type polymer. Although there are no special restrictions with regard to the state of component (B), it is preferable that at room temperature this component be in a liquid state for convenience as a powder treatment. [0008] The vinyl-type polymer can be obtained by subjecting (a) a vinyl monomer and (b) a vinyl-type monomer having in its molecule at least one silicon-bonded hydrogen atoms, or component (b) alone, to radical-polymerization. There are no special restrictions with regard to aforementioned vinyl monomer (a), provided that it has at least one radical-polymerizable vinyl groups and is free of a silicon-bonded hydrogen atom. [0009] The following are representative examples of vinyl monomers suitable for use as component (a): methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n- propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, or a similar lower alkylacrylate or methacrylate; n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl-acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, or a similar higher alkyl acrylate or methacrylate; vinyl acetate, vinyl propionate, or a similar lower alkyl-acid vinyl ester; vinyl caproate, vinyl 2-ethylhexanate, vinyl laurate, vinyl stearate, or a similar vinyl ester of higher fatty acid; styrene, vinyltoluene, or a similar styrene- type monomer; benzylacrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, vinyl pyrrolidone, or a similar acrylate or methacrylate with aromatic groups; acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N- methoxymethyl acrylamide, N-methoxymethyl methacrylamide, isobutoxy methoxyacrylamide, isobutoxymethoxy methacrylamide, N,N-dimethylacrylamide, N,N- dimethyl methacrylamide, or a similar vinyl-type monomer with an amide group; glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexyl methylacrylate, 3,4-epoxycyclohexyl methylmethacrylate, or a similar, epoxy-containing vinyl monomer; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2- hydroxypropyl methacrylate, 2- hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, or a similar vinyl-type monomer with a hydroxyl group; a vinyl-type monomer that contains a carboxylic-acid group such as acrylic acid, itaconic acid, crotonic acid, fumaric acid, or a maleic acid group; tetrahydiOfurfuryl acrylate, butoxyethyl acrylate, butoxyethyl methacrylate, ethoxydiethyleneglycol acrylate, ethoxydiethyleneglycol methacrylate, polyethyleneglycol acrylate, polyethyleneglycol methacrylate, polypropyleneglycol monoacrylate, polypropyleneglycol monomethacrylate, hydroxybutylvinyl ether, cetylvinyl ether, 2-ethylhexylvinyl ether, or a similar vinyl-type monomer with ether bonds; dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, or a similar vinyl-type monomer that contains an amino group; trifluoropropyl acrylate, trifluoropropylmethacrylate, perfluorobutylethyl methacrylate, perfluorobutylethyl acrylate, perfluorooctylethyl methacrylate, or a similar fluoro-containing vinyl-type monomer; butadiene, isoprene, or a similar diene-type monomer; vinyl chloride, vinylidene chloride, or a similar halogenated vinyl-type monomer; acrylonitrile or a similar nitrile-type monomer; a diorganopolysiloxane that contains in its side molecular chain a radical-polymerizable functional group such as acryl or methacryl group, styryl group, or the like; dibutyl fumarate; dodecyl anhydrous succmic acid; a radical-polymerizable unsaturated monomer that contains a sulfonic acid group such as styrene sulfonic acid; or alkali metal salts, or organic amine salts of the above acids; 2- hydroxy-3-methacryloxypropyltrimethyl ammonium chloride or a similar quaternary ammonium salt derived from a methacrylic acid, a methacrylic acid ester of an alcohol having a tertiary amine group such as methacrylic acid diethylamine ester, or quaternary ammonium salts of the above. [0010] Furthermore, component (a) may also comprise a multifunctional vinyl monomer. The following are representative examples of such monomers: allyl acrylate, allyl methacrylate, or a similar alkenyl acrylate or methacrylate; trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, ethyleneglycol diacrylate, ethyleneglycol dimethacrylate, tetraethyleneglycol diacrylate, polyethyleneglycol diacrylate, polyethyleneglycol dimethacrylate, 1,4-butadiol diacrylate, 1,4-butadiol dimethacrylate, 1,6-hexandediol diacrylate, 1,6-hexandediol dimethacrylate, neopentylglycol diacrylate, neopentylglycol dimethacrylate, trimethylolpropane trioxyethyl acrylate, trimethylolpropane trioxyethyl methacrylate, tris (2-hydroxyethyl) isocyanate diacrylate, tris (2-hydroxyethyl) isocyanate dimethacrylate, tris (2-hydroxyethyl) isocyanurate trimethacrylate, diacrylate or dimethacrylate of an ethylene oxide or propylene oxide adduct diol of a bisphenol A, an ethylene or propylene oxide adduct of a hydrated bisphenol A, diacrylate or methacrylate of diol, a polydimethyl siloxane having a methacryloxypropyl group, divinyl benzene, triethyleneglycol divinyl ether, and a polydimethyl siloxane having a styryl group. [0011] The following are representative examples of component (a): methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate or a similar lower alkyl acrylate or methacrylate; n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, or a similar higher alkyl acrylate or methacrylate.

[0012] A vinyl-type monomer (b) having in its molecule at least one silicon-bonded hydrogen atoms can be represented by the following chemical structural formula (1):

(1) where R¹ is an aryl group or an alkyl group with 1 to 10 carbon atoms, wherein the alkyl group can be represented by methyl group, ethyl group, propyl group, butyl group, pentyl group, isopropyl group, isobutyl group, cyclopentyl group, or cyclohexyl group. The aforementioned aiyl group can be represented by phenyl group or naphthyl group. Most preferable among these are methyl group or phenyl group, of which methyl group is the most preferable.

[0013] In the above formula, R² designates an aryl group or an alkyl group with 1 to 10 carbon atoms, an aryloxy group or an alkoxy group with 1 to 10 carbon atoms, of which the alkyl group can be represented by methyl group, ethyl group, propyl group, butyl group, pentyl group, isopropyl group, isobutyl group, cyclopentyl group, and cyclohexyl group. The aforementioned aryl group can be represented by phenyl group and naphthyl group.

Among these, the most preferable is methyl group. The aforementioned alkoxy group can be represented by methoxy group, ethoxy group, propoxy group, pentyloxy group, isopropoxy group, isobutoxy group, cyclopentyloxy group, and cyclohexyloxy group. The forementioned aryloxy group can be represented by phenoxy group and naphthyloxy group. The methoxy group is the most preferable. Other examples may include organopolysiloxanes which have molecular terminals capped with methacryloxy group, acryloxy groups, styryl groups, alkenyl groups, or similar radical-polymerizable groups, and which contain silicon-bonded hydrogen atoms on terminals or in side molecular chains. [0014] In the above formula, X designates a radical-polymerizable organic group, such as, e.g., an organic group that contains an acrylic or a methacrylic group and is represented by the following general formula (2) : R³ O

CH₂=C— C— O— R⁴— (2) or the following general formula (3) :

R R³ O

I

CH₂=C— C-NH-R⁴— ₍₃₎

or an alkenyl group with 2 to 10 carbon atoms or an organic group that contains a styryl group and is represented by the following general formula (4):

(4)

[0015] In the above formulae, R³ and R⁵ represent hydrogen atoms or methyl groups, R⁴ and R⁷ represent an alkylene group with 1 to 10 carbon atoms, and R⁶ represents an alkyl group with 1 to 10 carbon atoms; e is an integer from 0 to 4; and/is 0 or 1. Such radical- polymerizable organic groups can be represented, e.g., by an acryloxymethyl group, 3- acryloxypropyl group, methacryloxymethyl group, 3-methacryloxypropyl group, 4- vinylphenyl group, 3-vinylphenyl group, 4 -(2-propenyl) phenyl group, 3-(2-propenyl group) phenyl group, 2-(4-vinylphenyl) ethyl group, 2-(3-vinylphenyl) ethyl group, vinyl group, allyl group, methallyl group,, and 5-hexenyl group; a is a number (except for 0), which is equal to or less than 3; b is a number which is equal to or less than 3; c is 0 or a number equal to or less than 3; and a + b + c = 3. The vinyl-type monomer (b) is preferably a vinyl monomer having in its molecule at least one silicon-bonded hydrogen atoms represented by the general formula (1) wherein Ri is alkyl group with 1 to 10 carbon atoms, a is 3, b and c are 0, X is represented by the formula (2);

R³ O CH₂=C— C— O— R⁴— (2) wherein R³ represents hydrogen atom or methyl group, R⁴ represents an alkylene group with 1 to 10 carbon atoms.

[0016] The aforementioned component b can be represented by compounds of the following chemical structural formulae, where Me stands for methyl group:

Me CH₂=C-C-0-C₃H₆ — Si(OSiHMe₂)₃ δ

CH₂=C-C-0-C₃H₆— Si(OSiHMe₂)₃ δ

CH₂=CH -C₂H₄-Si(OSiHMe₂)₃ CH₂=CH— Si-(OSiHMe₂)₃

[0017] The aforementioned compounds can be prepared by the methods known in the art. Furthermore, organopolysiloxanes having on one of their molecular terminals a radical- polymerizable group such as methacryloxy group, acryloxy group, styryl group, alkenyl group, or the like and having at least one silicon-bonded hydrogen atoms in side molecular chains and/ or on another terminals are available for the same purposes. They are preferably organopolysiloxanes having on one of molecular terminals a methacryloxyalkyl group and having silicon-bonded hydrogen atoms in side molecular chains and/or on another terminals. Component (b) should be used in an amount of 0.1 to 100 wt.%, preferably of 1 to 100 wt.% relative to the total weight of components (a) and (b).

[0018] Component (B) can be prepared by radical-polymerizing both components (a) and (b) or component (b) alone. The radical-polymerization reaction can be carried out in the presence, as well as in the absence, of an organic solvent. When an organic solvent is used, the reaction should be carried out in the presence of a radical initiator for 3 to 20 hours at a temperature from 50 to 150°C. The following organic solvents are suitable for the aforementioned reaction: hexane, octane, decane, cyclohexane, or a similar aliphatic hydrocarbon; benzene, toluene, xylene, or a similar aromatic hydrocarbon; diethyl ether, dibutylether tetrahydrofuran, dioxane, or a similar ether; acetone, methylethylketone, methylisobutylketone, diisobutylketone, or a similar ketone; methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, or methanol, ethanol, isopropanol, butanol, or a similar alcohol. Most preferable of these are toluene or xylene. Radical initiators may be the same as those used for conventional radical-polymerization reactions. The following are examples of such compounds: 2,2'-azobis (isobutylonitrile), 2,2'-azobis (2-methylbutylonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), or a similar azobis-type compound; benzoyl peroxide, lauroyl peroxide, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, or a similar organic peroxide. Typically, the radical initiator is used in an amount of 0.1 to 5 parts by weight for each 100 parts by weight of the total weight of aforementioned components (a) and (b) or the weight of component (b) alone. If necessary, the radical-polymerization reaction can be carried out with the addition of a chain-transfer agent that can be represented by 2- mercaptoethanol, butylmercaptane, n-dodecylmercaptane, 3-mercaptopropyl trimethoxysilane, or a similar mercapto compound; ethylene chloride, chloroform, carbon tetrachloride, butyl bromide, 3-chloropropyltrimethoxysilane, or a similar halide. [0019] Component (B) may also contain at least one silicon-bonded alkoxy groups, in addition to the silicon-bonded hydrogen atom that is required in its molecule. Such compounds that have silicon-bonded alkoxy groups are obtained by copolymerizing a vinyl monomer having at least one alkoxysilyl groups in the molecule, herein designated as component (c), with components (a) and (b), as defined supra. Component (c) can be represented by the following general formula (5) :

X - S i - (O R ⁹) _g (R ^{1 0}) _h

(5) wherein X designates a radical-polymerizable organic group, which can be expressed, e.g., by the following formula (6) :

R¹¹ O CH₂=C— C— O— R¹²- (₆)

an acryl or a methacryl group of the following formula (7) :

or an alkenyl group with 2 to 10 carbon atoms, or an organic group having a styryl group and represented by the following general formula (8):

[0020] In this formula, R and R are hydrogen atoms or methyl groups; R and R are alkylene groups with 1 to 10 carbon atoms, R¹⁴ is an alkyl group with 1 to 10 carbon atoms; i designates an integer from 0 to 4, andj is 0 or 1. The following are representative examples of the aforementioned radical-polymerizable organic groups: an acryloxymethyl group, 3- acryloxypropyl group, methacryloxymethyl group, 3-methacryloxypropyl group, 4- vinylphenyl group, 3-vinylphenyl group, 4-(2-propenyl) phenyl group, 3-(2-propenyl) phenyl group, 2-(4-vinylphenyl) ethyl group, 2-(3 -vinylphenyl) ethyl group, vinyl group, allyl group, methallyl group, and 5-hexenyl group.

[0021] In the above formula, R⁹ designates an aryl group or an alkyl group with 1 to 10 carbon atoms. The aforementioned alkyl group can be exemplified by methyl group, ethyl group, propyl group, butyl group, pentyl group, isopropyl group, isobutyl group, cyclopentyl group, and cyclohexyl group. The aforementioned aryl group can be exemplified by phenyl group and naphthyl group. The most preferable of theses are methyl group and phenyl group, and especially, methyl group. In the above formula, R¹⁰ designates an aryl group or an alkyl group with 1 to 10 carbon atoms. The alkyl group may comprise methyl group, ethyl group, propyl group, butyl group, pentyl group, isopropyl group, isobutyl group, cyclopentyl group, and cyclohexyl group. The aryl group may comprise phenyl group and naphthyl group. The most preferable of these are the methyl group and the phenyl group, and especially, the methyl group. Furthermore, g is a positive number which is 3 or less, but excluding 0; h is a positive number which is 0 or 3 or less, and g + h = 3.

[0022] Component (c) can be exemplified by compounds represented by the following structural formulae:

CH₂=C ¥-Si(OMe)₃

CH₂=CH- \ -Si-(OMe)₃

CH₂=CH- \ -C₂H₄-Si(OMe)₃

CH₂=CH— Si-(OMe)₃

[0023] It is recommended to use component (B) in an amount from 0.01 to 50 parts by weight, preferably from 0.1 to 20 parts by weight, for each 100 parts by weight of component (A). If component (B) is used in an amount less than 0.01 parts by weight, there will be no compounding effect, and if the content of component (B) exceeds 50 parts by weight, the thermoplastic resin composition that comprises a mixture with component (A) will have a reduced molten-state viscosity and an insufficient moldability. [0024] Inorganic powder, component (C), can be selected from any of the known conventional inorganic powders, which are typically added, for example, as fillers or pigments to thermoplastic resins. The following are representative examples of such inorganic powders: titanium oxide, zinc oxide, alumina, silica, calcium oxide, magnesium oxide, iron oxide, antimony oxide, ferrite, or a similar metal oxide; calcium hydroxide, magnesium hydroxide, aluminum hydroxide, or a similar metal hydroxide; calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dorsonite, hydrotalcite, or a similar carbonate; calcium sulfate, barium sulfate, gypsum, or a similar sulfate; silica, calcium silicate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, or similar silicates; aluminum nitride, boron nitride, silicon nitride, or a similar nitride. More suitable ones of the above are metal oxide powders which can be used as white pigments. Most suitable ones are titanium oxide powders, more specifically titanium dioxide powders such as rutile-type titanium dioxide powder and anatase-type titanium dioxide powder which are typical white pigments. [0025] Typically, component (C ) is used in an amount from 0.01 to 200 parts by weight, preferably 0.1 to 100 parts by weight, and even more preferably, 0.2 to 50 parts by weight for each 100 parts by weight of component (A). If component (C) is used in an amount less than 0.1 parts by weight, it will not produce any effects. If, on the other hand, component (C) is used in an amount exceeding 200, it will reduce mechanical strength of the obtained thermoplastic resin composition.

[0026] The thermoplastic resin composition of the present invention is prepared from aforementioned components (A) through (C). If necessary, however, the composition may incorporate various known additives which are normally added to thermoplastic resins, such as an ultraviolet-ray absorbent, light-resistant agent, oxidation-resistant agent, plasticizer, antifoaming agent, lubricant, anti-static agent, conductivity-imparting agent, pigment, dye, or a similar coloring agent, compatibility improving agent, cross-linking agent, flame-retarding agent, anti-corrosive agent, anti-shrinking agent, thickener, mold-release agent, bactericidal agent, blue-ink agent, silane-coupling agent, etc. These agents can be added in quantities, which are not in conflict with the purposes of the present invention. [0027] The thermoplastic resin composition of the present invention can be easily prepared by uniformly mixing components (A) to (C), if necessary, with the addition of appropriate additives. Mixing can be carried out with the use of a Banbury mixer, kneader- mixer, hot double-roller mill, or similar rotary-type mixers or kneaders, as well as with the use of a single-screw extruder, double-screw extruder, or a similar continuous-action mixing- kneading extruders.

Examples

[0028] In the following examples, all parts are parts by weight, Me designates methyl group, and viscosities have values measured at 25°C.

[0029] The following methods were used for measuring and evaluating molded articles with regard to appearance, whiteness degree, Izod impact strength, and molecular weight of a polycarbonate resin. [0030] Appearance of the Molded Article

A disk-like article having a 4 cm diameter and a 2 mm thickness was molded with the use of a small injection-molding machine (from CSI, Japan) equipped with a die having a mirror- finished chromium-plated working surface. Appearance of the molded article was evaluated by visual observation with naked eye.

[0031] Whiteness Degree of the Molded Article

The surface of the obtained 4 cm-diameter, 2 mm-thick disk-like sample was measured with the use of a color difference meter (Model CR-200 from Minolta Camera Co., Ltd, Japan) and the whiteness degree (%) was determined by means of the formula;

Whiteness Degree (%) = 100 - [(100 - L)² + (a² + b²)]^1/2 where L is so-called luminosity in the Lab color indication system, and a and b are perceived color indicators used in the Lab color indication system.

[0032] Izod Impact Strength of the Molded Article

This property was measured in accordance with JIS K7110. More specifically, specimens were molded using a small injection-molding machine (from CSI, Japan) and measured with respect to the Izod impact strength (on a specimen with a notch) in accordance with the provisions of JIS K7110.

[0033] Molecular Weight of Polycarbonate Resin In the Molded Article

After centrifugal separation of a polycarbonate resin dissolved in chloroform, the supernatant was analyzed by means of gel-permeation chromatography (GPC). Refractory index (RI) and ultraviolet-radiation (UV) detection devices were used in the analysis. The obtained dissolution curve was evaluated using polystyrene with the reference molecular weight, and the molecular weight {a number-average molecular weight (Mn)} of the polycarbonate was recalculated for the reference-molecular-weight polystyrene resin.

[0034] Reference Example 1

A 200 mL four-neck flask equipped with a stirrer, thermometer, and refluxing tube was loaded with 65 g of n-butyl acrylate (hereinafter referred to as nBA), 30 g of a vinyl monomer represented by the chemical structural formula (9) given below and having silicon-bonded hydrogen atoms {γ-methacryloxypropyl tris(dimethylhydrogensiloxy) silane}, 5 g of a y - mercaptopropyltrimethoxysilane, 2 g of 2,2'-azobis-2-methylbutylonitrile hereinafter referred to as AMBN) (from Otsuka Chemical Vo., Ltd., Japan), and 100 g of toluene. The components were then stirred with heating for 6 hours at 70°C in a nitrogen atmosphere. Low- volatility components were removed by means of an aspirator and a vacuum pump while stirring the reaction mixture with heating under vacuum. The obtained reaction mixture was filtered through a 200-mesh metal net filter. The resulting product comprised 88 g of a copolymer of n-butyl acrylate and the vinyl monomer represented by the chemical structural formula (9) having silicon-bonded hydrogen atoms in its molecule {hereinafter referred to as a PBA copolymer (B-l)} . Components for preparing this copolymer are shown in Table 1. The copolymer was evaluated with regard to its color tone, and its viscosit. Its molecular weight was measured by gel permeation chromatography (GPC) and was recalculated to the molecular weight {number-average molecular weight (Mn)} of a reference-molecular- weight polystyrene resin. The results of the evaluation and measurement are presented in Table 1.

Me CH₂=C-C-0-C₃H₆ — Si(OSiHMe₂)₃ δ

(9)

[0035] Reference Example 2

First, 93 g of a polytbutylacrylate copolymer containing in its molecule silicon-bonded hydrogen atoms and silicon-bonded methoxy groups {hereinafter referred to as PBA copolymer (B-2)} were obtained by the same method as in Reference Example 1, with the exception that 15 g of a vinyl monomer represented by the chemical structural formula (9) having silicon bonded hydrogen atoms and 15 g of a vinyl monomer represented by the chemical structural formula (10) were used instead of 30 g of the vinyl monomer represented by the chemical structural formula (9) with silicon-bonded hydrogen atoms. Then, the obtained copolymer was evaluated with regard to its color tone, and its viscosity and molecular weight were measured. The results of the evaluation and measurement are presented in Table 1.

(10)

Table 1

[0036] Example 1

A 30 cm³ LabPlast Mill (from Toyo Seiki Seisakusho Ltd., Japan) was filled with 100 parts of an aromatic polycarbonate resin (TAFURON™ A1900 from Idemitsu Petrochemical Co., Ltd., Japan, having an number-average molecular weight Mn = 18000) 1 part of the PBA copolymer (B-l) obtained in Reference Example 1, and 10 parts of a rutile-type titanium- dioxide powder (TIPAQUE™ CR-60 from Ishihara Sangyo Co., Ltd., Japan, having an average grain diameter of 0.21 μm). The components were kneaded for 10 min. at 280°C and 100 rpm to produce a polycarbonate resin composition. The measured physical properties of the obtained thermoplastic resin composition are summarized in Tables 2 and 3.

[0037] Example 2

A polycarbonate resin composition was produced by the same method as in Example 1, with the exception that 1 part of the PBA copolymer (B-2) was used instead of 1 part of the PBA copolymer (B-l). The measured physical properties of the obtained polycarbonate resin composition are summarized in Tables 2 and 3. [0038] Comparative Example 1

A polycarbonate resin composition was produced by the same method as in Example 1, with the exception that the PBA copolymer (B-l) was not used. The measured physical properties of the obtained polycarbonate resin composition are summarized in Tables 2 and 3.

[0039] Comparative Example 2

A polycarbonate resin composition was produced by the same method as in Example 1, with the exception that 1 part of trimethylsiloxy-endblocked methylhydrogenpolysiloxane having a viscosity of 20 mPa-s (SHI 107 from Dow Corning Toray Silicone Co., Ltd., Japan) was used instead of 1 part by weight of the PBA copolymer (B-l). The measured physical properties of the obtained polycarbonate resin composition are summarized in Tables 2 and 3.

[0040] Comparative Example 3

A polycarbonate resin composition was produced by the same method as in Example 1. However, 1 part of the PBA copolymer (B-l) used in Example 1 and obtained in Reference Example 1 was replaced by 1 part of trimethylsiloxy-endblocked polydimethylsiloxane in which a part of methyl groups in the side molecular chains were substituted by trimethoxysilylethyl groups with a viscosity of 40 mPa-s (BY16-160 from Dow Corning Toray Silicone Co., Japan). The polydimethylsiloxane used in this example was free of silicon- bonded hydrogen atoms. Characteristics of the obtained polycarbonate resin composition were measured. The measured physical properties of the obtained polycarbonate resin composition are summarized in Tables 2 and 3.

Table 2

Table 3

[0041] Example 3

A 30 cm³ LabPlast mill (from Toyo Seiki Seisakusho Ltd., Japan) was filled with 100 parts of a polypropylene resin (NOBLEN™ Y101 from Sumitomo Chemical Industries Co., Ltd., Japan), 1 part of the PBA copolymer (B-l) obtained in Reference Example 1, and 10 parts of rutile-type titanium-dioxide powder having an average grain diameter 0.02 to 0.05 μm (TTO™-55(B) from Ishihara Sangyo Co., Ltd., Japan). The components were kneaded for 10 min. at 240°C and 100 rpm. As a result, a polypropylene resin composition was produced. The obtained resin composition was evaluated with regard to its appearance. The evaluation result is shown in Table 4. [0042] Comparative Example 4

A polypropylene resin composition was produced by the same method as in Example 3, with the exception that the PBA copolymer (B-l) used in Example 3 was not used. As a result, a polypropylene resin composition was produced. The obtained resin composition was evaluated with regard to its appearance. The evaluation result is shown in Table 4.

[0043] Example 4

A 30 cm³ LabPlast mill (from Toyo Seiki Seisakusho Ltd., Japan) was filled with 100 parts of a high-impact polystyrene resin (STYRON™ 492 from Asahi Chemical Industries Co., Ltd., Japan), 1 part of the PBA copolymer (B-l) obtained in Reference Example 1, and 10 parts of a rutile-type titanium-dioxide powder having an average grain diameter of 0.02 to 0.05 μm (TTO™-55(B) from Ishihara Sangyo Co., Ltd., Japan). The components were kneaded for 10 min. at 220°C and 100 rpm. As a result, a high-impact polystyrene resin composition was produced. The obtained resin composition was evaluated with regard to its appearance. The evaluation result is shown in Table 4.

[0044] Comparative Example 5

A high-impact polystyrene resin composition was produced by the same method as in Example 4, with the exception that the PBA polymer (B-l) of Example 3 was not used. The obtained resin composition was evaluated with regard to its appearance. The evaluation result is shown in Table 4.

Table 4

Example Example 4 Comp. Comp. Ex.

3 Ex. 4 5

Composition

Polypropylene resin (parts) 100 100

High-Impact polystyrene resin (parts) 100 100

PBA copolymer (B-I) 1 1

(parts)

Titanium dioxide (parts) 10 10 10 10

Characteristics

Appearance White Yellowish Yellow Yellowish white brown

Claims

1. A thermoplastic resin composition comprising:

(A) 100 parts by weight of a thermoplastic resin; (B) 0.01 to 50 parts by weight of a vinyl-type polymer having at least one silicon- bonded hydrogen atoms in its molecule; and (C) 0.01 to 200 parts by weight of an inorganic powder.

2. The thermoplastic resin composition of claim 1 wherein the thermoplastic resin is selected from polycarbonate, polyolefm, and polystyrene resins.

3. The thermoplastic resin composition of claim 1 , wherein component (B) is a radical polymerization product of monomers comprising;

(a) a first vinyl monomer, and

(b) a second vinyl monomer having in its molecule at least one silicon-bonded hydrogen atoms, with the proviso that the first vinyl monomer is free of a silicon-bonded hydrogen atom, or (b) alone.

4. The thermoplastic resin composition of claim 3, wherein the first vinyl monomer (a) is a acrylic acid ester or methacrylic acid ester, and the second vinyl monomer (b) is a organosilane represented by the general formula (1);

(1)

1 9 where R is an aryl group or an alkyl group with 1 to 10 carbon atoms, R designates an aryl group or an alkyl group with 1 to 10 carbon atoms, an aryloxy group or an alkoxy group with 1 to 10 carbon atoms, X designates a radical-polymerizable organic group, a is a number (except for 0), which is equal to or less than 3; b is a number, which is equal to or less than 3; c is 0 or a number equal to or less than 3; and a + b + c = 3, or an organopolysiloxane having on one of molecular terminals a methacryloxyalkyl group and having silicon-bonded hydrogen atoms in side molecular chains and/or on another terminals.

5. The thermoplastic resin composition of claim 4, wherein the first vinyl monomer (a) is an alkyl acrylate, and the second vinyl monomer (b) is the organosilane having in its molecule at least one silicon-bonded hydrogen atoms represented by the general formula (1) wherein Ri is alkyl group with 1 to 10 carbon atoms, a is 3, b and c are 0, X is represented by the formula (2):

(2) wherein R³ represent tss hhyyddrrooggeenn aattoomm c or methyl group, R⁴ represents an alkylene group with 1 to 10 carbon atoms,.

6. The thermoplastic resin composition of claim 5, wherein the first vinyl monomer (a) is an n-butyl acrylate, and the second vinyl monomer (b) is γ- mβthacryloxypropyl tris(dimethylhydrogensiloxy) silane .

7. The thermoplastic resin composition of claim 3, wherein component (B) is a radical polymerization product of monomers comprising;

(a) a first vinyl monomer,

(b) a second vinyl monomer having in its molecule at least one silicon-bonded hydrogen atoms, and (c) a third vinyl monomer having at least one alkoxysilyl groups in its molecule, with the proviso that the first vinyl monomer is free of a silicon-bonded hydrogen and the third vinyl monomer is free of a silicon-bonded hydrogen atom.

8. The thermoplastic resin composition of claim 7, wherein the third vinyl monomer (c) contains an acryl or a methacrylic group.

9. The thermoplastic resin composition of claim 1 , wherein said component (C) is a white pigment powder.

10. The thermoplastic resin composition of claim 9, wherein said white pigment powder is a white metal oxide powder.

11. The thermoplastic resin composition of claim 10, wherein said metal oxide powder is titanium oxide powder.