JP2003096314A - Resin powder, molded form and manufacturing method for molded form - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin powder excellent in powder fluidity from which a molded form excellent in a mold-releasing property from a metal mold can be obtained, further to provide the molded form consisting of powdery molding of the resin powder and a manufacturing method for the molded form from the powdery molding. SOLUTION: The resin powder comprises a dry blend of 100 pts.wt. of a thermoplastic elastomer powder having 30-1,000 μm average particle size with 0.1-10 pts.wt. of a silicone rubber powder having 0.1-10 μm average particle size, the molded form comprises powdery molding of the resin powder, and the manufacturing method for the molded form comprises powdery molding of the resin powder.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin powder, a molded product, and a method for producing a molded product. More specifically, the present invention makes it possible to obtain a molded article having excellent mold releasability, a resin powder having excellent powder flowability, a molded article obtained by powder molding the resin powder, and a molded article produced by the powder molding. It is about how to do it.

[0002]

2. Description of the Related Art As a skin material for automobile interior parts and the like, a sheet-shaped molded article having a complicated uneven pattern such as a skin grain or stitch is used on the surface. Such a molded body is
For example, JP-A-5-1183 and JP-A-5-50.
As disclosed in Japanese Patent Publication No. 50, it is produced by powder molding a thermoplastic elastomer powder.
Since the powder does not have sufficient powder fluidity, the appearance of pinholes, underfills, etc. at the edges of the convex parts when manufacturing a molded product having a complicated shape, for example, a molded product having a narrow and high convex portion. There was a problem that defects might occur.
As a method for solving such a problem, for example, Japanese Patent Application Laid-Open No. 11-286578 discloses a method in which a powder made of alumina or silica and having a primary particle size of 300 nm or less is mixed with a thermoplastic elastomer composition powder. It is disclosed.

[0003]

In the method of blending the above-mentioned powder made of alumina or silica with the thermoplastic elastomer composition powder, the releasability between the molded body and the mold may be inferior. At the time of taking out from the mold, problems such as breakage and wrinkling of the molded product and breakage of the molded product may occur. Under such circumstances, the problem to be solved by the present invention is to provide a resin powder having excellent powder fluidity, which makes it possible to obtain a molded product having excellent mold releasability from a mold. Further, it is to provide a molded product obtained by powder molding the resin powder and a method for producing the molded product by powder molding.

[0004]

That is, the first aspect of the present invention is to provide 100 parts by weight of a thermoplastic elastomer powder having an average particle size of 30 to 1000 μm and an average particle size of 0.1 to 0.1 μm.
The present invention relates to a resin powder obtained by dry blending 0.1 to 10 parts by weight of silicone rubber powder having a size of 10 μm. A second aspect of the present invention relates to a molded body obtained by powder molding the above resin powder. The third aspect of the present invention is
The present invention relates to a method for producing the molded body.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic elastomer used in the thermoplastic elastomer powder of the present invention is JIS
K-6301 (1975) is a thermoplastic resin having an A hardness of 98 or less, and is an olefin-based thermoplastic elastomer (A), a styrene-based thermoplastic elastomer (B), a polyester-based thermoplastic elastomer (C), or a polyurethane-based heat. There are thermoplastic elastomer (D), polyamide thermoplastic elastomer (E), and polyvinyl chloride thermoplastic elastomer (F). These are used alone or in combination of two or more.

Olefinic thermoplastic elastomer (A)
Is a composition (a1) of a polyolefin resin and a polyolefin rubber, a conjugated diene polymer (a2), and a hydrogenated product (a3) of a conjugated diene polymer, and these are one kind or two kinds.
Used in combination of two or more species.

The polyolefin resin used in the composition (a1) of the polyolefin resin and the polyolefin rubber is one or more olefins having 2 to 10 carbon atoms such as ethylene, propylene, 1-butene and 1-hexene. A polymer containing at least 50% by weight of a repeating unit derived from, and containing no repeating unit derived from a vinyl aromatic compound, according to JIS K-6301 (1
975) is a polymer having an A hardness of more than 98. The polyolefin resin may contain a repeating unit derived from a monomer other than olefin, and examples of the monomer other than olefin include, for example, a conjugated diene used in a conjugated diene polymer (a2) described below; Cyclopentadiene, 5-ethylidene-2-norbornene, 1,4-hexadiene, 1,5-dicyclooctadiene, 7-methyl-1,6-octadiene, 5-vinyl-2-norbornene and the like having 5 carbon atoms 15 non-conjugated dienes; vinyl ester compounds such as vinyl acetate; unsaturated carboxylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate; unsaturated such as acrylic acid and methacrylic acid Examples include carboxylic acids.

As the polyolefin resin, for example,
Polyethylene, polypropylene, poly 1-butene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1
-Octene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-
1-octene copolymers, propylene-1-butene-ethylene copolymers, propylene-1-hexene-ethylene copolymers, propylene-1-octene-ethylene copolymers, and these polyolefin resins may be used alone or Two
Used in combination of two or more species. These can be manufactured by a known method.

Among the polyolefin resins, polypropylene resins having a content of repeating units derived from propylene of 80% by weight or more are preferable from the viewpoint of heat resistance. The content of repeating units derived from propylene in the polypropylene resin is more preferably 90% by weight or more, and further preferably 95% by weight or more.

The melt flow rate (MFR) of the polyolefin resin is preferably in the range of 10 to 500 g / 10 minutes, more preferably 50 to 400 g / 10 minutes, still more preferably 100 to 300 g / 10 minutes. If the MFR is too low, the melt moldability of the resin powder of the present invention may decrease, and if it is too high, the strength of the obtained molded product may decrease. The MFR is JIS K-721.
0 (1976), temperature 230 ℃, load 21.1
It is measured under the condition of 8N.

The polyolefin rubber used in the composition (a1) of the polyolefin resin and the polyolefin rubber is carbon such as ethylene, propylene, 1-butene, 2-methylpropylene, 3-methyl-1-butene, 1-hexene. A polymer containing 50% by weight or more of a repeating unit derived from one or two or more olefins having 2 to 10 atoms, which does not contain a repeating unit derived from a vinyl aromatic compound. 6301 (197)
It is a polymer having A hardness of 5) of 98 or less. The polyolefin rubber may contain a repeating unit derived from a monomer other than olefin, and examples of the monomer other than olefin include, for example, the conjugated diene polymer (a2) described below.
Conjugated diene used in; dicyclopentadiene, 5-
Ethylidene-2-norbornene, 1,4-hexadiene, 1,5-dicyclooctadiene, 7-methyl-1,
Non-conjugated dienes having 5 to 15 carbon atoms such as 6-octadiene and 5-vinyl-2-norbornene; vinyl ester compounds such as vinyl acetate; methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, methacrylic acid Unsaturated carboxylic acid esters such as ethyl; unsaturated carboxylic acids such as acrylic acid and methacrylic acid.

As the polyolefin rubber, for example,
Polypropylene, poly 1-butene, poly 2-methylpropane, ethylene-propylene copolymer, ethylene-1-
Butene copolymer, ethylene-3-methyl-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-
1-octene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-
1-octene copolymer, ethylene-propylene-5-ethylidene-2-norbornene copolymer, propylene-1
Examples thereof include butene-ethylene copolymer, propylene-1-hexene-ethylene copolymer, and propylene-1-octene-ethylene copolymer, and these polyolefin rubbers may be used alone or in combination of two or more. These can be manufactured by a known method.

The weight ratio of polyolefin resin to polyolefin rubber in the composition (a1) of polyolefin resin and polyolefin rubber (polyolefin resin / polyolefin rubber) is 5/95 to 95/5, preferably 20/80 to. 50/50, more preferably 30 /
70-45 / 55. When the weight ratio of the polyolefin resin in the composition (a1) is less than 5% by weight, the heat resistance may decrease, and when it exceeds 95% by weight, the flexibility of the obtained molded article may decrease. is there.

The composition (a1) of the polyolefin resin and the polyolefin rubber may be cold blended by using a tumble mixer or the like, or a single screw extruder, a twin screw extruder, a kneader, a roll, a Banbury mixer or the like. You may perform melt-kneading using it. When melt-kneading, all the components to be kneaded may be melt-kneaded together, or some components may be kneaded and then unselected components may be added and melt-kneaded.

The composition (a1) of the polyolefin resin and the polyolefin rubber may be subjected to a crosslinking treatment, and the crosslinking treatment may improve the heat resistance. As the method of crosslinking treatment, for example, the dynamic crosslinking method described in JP-A-5-5050 can be used. When performing dynamic crosslinking, all of the raw materials used may be dynamically crosslinked, or a part of the raw materials may be dynamically crosslinked and then the remaining raw materials may be added and melt-kneaded.

The conjugated diene polymer (a2) is 1,3-
Butadiene, 2-methyl-1,3-butadiene (isoprene), 1,3-pentadiene, 2,3-dimethyl-
Conjugated diene 1 having 4 to 8 carbon atoms such as 1,3-butadiene
It is a polymer having a repeating unit content of 50% by weight or more and containing no repeating unit derived from a vinyl aromatic compound. The conjugated diene polymer (a2) may contain a repeating unit derived from a monomer other than the conjugated diene, and examples of the monomer other than the conjugated diene include ethylene, propylene and 1-butene. Olefins having 2 to 10 carbon atoms; dicyclopentadiene, 5-ethylidene-2-norbornene, 1,4-hexadiene, 1,5-dicyclooctadiene, 7-methyl-1,6-octadiene, 5-
Non-conjugated dienes having 5 to 15 carbon atoms such as vinyl-2-norbornene; vinyl ester compounds such as vinyl acetate; methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, glycidyl acrylate, Glycidyl methacrylate, hydroxyethyl acrylate, unsaturated carboxylic acid esters such as dimethylaminoethyl methacrylate; acrylic acid,
Unsaturated carboxylic acids such as methacrylic acid; unsaturated dicarboxylic acids such as maleic acid; acid anhydrides such as maleic anhydride; epoxy group-containing vinyl compounds such as allyl glycidyl ether; isocyanate group-containing vinyl compounds such as isopropenyl isocyanate; acrylonitrile. And vinyl nitrile compounds such as methacrylonitrile. Examples of the conjugated diene polymer (a2) include poly 1,3-butadiene, polyisoprene, and 1,3.
-Butadiene-isoprene copolymer may be mentioned, and these conjugated diene polymers (a2) may be used alone or in combination of two or more. These can be manufactured by a known method.

The conjugated diene polymer (a2) may have a structure of one block or may have two or more blocks of different structures. Examples of the structure having one block include a conjugated diene and a polymer having a structure in which conjugated dienes are randomly arranged, for example, a polymer having a structure in which 1,3-butadiene and isoprene are randomly arranged. Examples of the block composed of two or more blocks having different structures include, for example, a copolymer composed of 1,3-butadiene homopolymer block-isoprene homopolymer block-1,3-butadiene homopolymer block, 1 , 3-Butadiene 1,4-addition polymer block-1,3-Butadiene 1,2-addition polymer block-1,3-Butadiene 1,4 addition polymer block, 1,3 -Butadiene 1,4-addition polymer block-1,3-Butadiene 1,2-addition-
1,4 addition polymer block-1,3-butadiene 1,
Polymers composed of 4-addition polymer blocks are mentioned. In such polymers, 1,3-butadiene 1,2
Addition-1,4 addition polymer blocks are 1,2 addition and 1,4 addition
It may be a block having a structure in which the addition is randomly polymerized, or may be a block having a tapered structure in which the content of 1,2 addition is gradually reduced.

The hydrogenated product (a3) of the conjugated diene polymer is
A polymer obtained by hydrogenating the aforementioned conjugated diene polymer (a2), which is a conjugated diene polymer (a2)
Like, the structure may consist of one block,
It may be composed of two or more blocks having different structures.
Examples of the hydrogenated product (a3) of the conjugated diene polymer include hydrogenated poly-1,3-butadiene, hydrogenated polyisoprene, and hydrogenated 1,3-butadiene-isoprene copolymer. They may be used alone or in combination of two or more.

The styrene-based thermoplastic elastomer (B) is a repeating unit derived from one or more vinyl aromatic compounds having 8 to 12 carbon atoms such as styrene, p-methylstyrene and α-methylstyrene. It is a polymer contained, which is a copolymer of a vinyl aromatic compound and a conjugated diene (b1), a hydrogenated product of a copolymer of a vinyl aromatic compound and a conjugated diene (b2), a copolymer of a vinyl aromatic compound and an olefin. It is a combination (b3). These copolymers may be used alone or in combination of two or more.

The conjugated diene used in the copolymer (b1) of the vinyl aromatic compound and the conjugated diene is 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 1,3-pentadiene, 2 , 3-dimethyl-1,
It is a conjugated diene having 4 to 8 carbon atoms such as 3-butadiene, and these are used alone or in combination of two or more. The olefin used in the copolymer (b3) of the vinyl aromatic compound and the olefin is an olefin having 2 to 10 carbon atoms such as ethylene, propylene and 1-butene, and these are used alone or in combination of two or more.

The copolymer of a vinyl aromatic compound and a conjugated diene (b1) and the copolymer of a vinyl aromatic compound and an olefin (b3) are different from repeating units derived from a vinyl aromatic compound, a conjugated diene and an olefin. It may contain a monomer unit. Examples of the monomer for deriving the monomer unit include dicyclopentadiene, 5-ethylidene-2-norbornene, 1,4-hexadiene, 1,
Non-conjugated dienes having 5 to 15 carbon atoms such as 5-dicyclooctadiene, 7-methyl-1,6-octadiene and 5-vinyl-2-norbornene; vinyl ester compounds such as vinyl acetate; methyl acrylate, acryl Unsaturated carboxylic acid esters such as ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate, dimethylaminoethyl methacrylate; unsaturated carboxylic acids such as acrylic acid and methacrylic acid. Acids; unsaturated dicarboxylic acids such as maleic acid; acid anhydrides such as maleic anhydride; epoxy group-containing vinyl compounds such as allyl glycidyl ether; isocyanate group-containing vinyl compounds such as isopropenyl isocyanate; acrylonitrile, methacryl Vinyl nitrile compounds such as nitriles.

Examples of the copolymer (b1) of a vinyl aromatic compound and a conjugated diene include a styrene-1,3-butadiene copolymer and a styrene-isoprene copolymer, and the vinyl aromatic compound and the olefin. Examples of the copolymer (b3) with styrene include a styrene-ethylene copolymer and a styrene-propylene copolymer. These are used alone or in combination of two or more. Moreover, these can be manufactured by a well-known method.

The copolymer (b1) of a vinyl aromatic compound and a conjugated diene and the copolymer (b3) of a vinyl aromatic compound and an olefin may have one structure or two or more different structures. May be composed of blocks. As the structure consists of one block,
Examples thereof include a copolymer having a structure in which a vinyl aromatic compound and a conjugated diene or olefin are randomly arranged, such as a styrene-butadiene random copolymer and a styrene-isoprene random copolymer. Examples of the block composed of two or more blocks having different structures are, for example, a copolymer composed of a styrene homopolymer block-butadiene homopolymer and a copolymer composed of a styrene homopolymer block-isoprene homopolymer block. Copolymer,
Styrene homopolymer block-butadiene homopolymer block-styrene homopolymer block copolymer, styrene homopolymer block-isoprene homopolymer block-styrene homopolymer block copolymer, Styrene homopolymer block-butadiene-isoprene copolymer block-copolymer composed of styrene homopolymer block, styrene homopolymer block-styrene-butadiene copolymer block-
Examples of the copolymer include styrene homopolymer blocks. In such a copolymer, the styrene-butadiene copolymer block may be a block having a structure in which styrene and butadiene are randomly copolymerized, or styrene. It may be a block having a tapered structure in which the unit content is gradually reduced.

The hydrogenated product (b2) of a copolymer of a vinyl aromatic compound and a conjugated diene is a polymer obtained by hydrogenating the above-mentioned copolymer (b1) of a vinyl aromatic compound and a conjugated diene. As with the copolymer (b1) of the vinyl aromatic compound and the conjugated diene, the structure may be composed of one block, or the structure may be composed of two or more blocks having different structures. Examples of hydrogenated products (b2) of copolymers of vinyl aromatic compounds and conjugated dienes include hydrogenated styrene-1,3-butadiene copolymers and hydrogenated styrene-isoprene copolymers. They may be used alone or in combination of two or more.

The hydrogenated product (b2) of a copolymer of a vinyl aromatic compound and a conjugated diene is disclosed in, for example, JP-A-2-36244.
Japanese Patent Laid-Open No. 3-72512, Japanese Patent Laid-Open No. 3-72
It can be produced by the methods described in JP-A-5123, JP-A-7-118335, JP-A-56-38338 and JP-A-61-60739.

The content of repeating units derived from the vinyl aromatic compound in the copolymer (b1) of vinyl aromatic compound and conjugated diene or its hydrogenated product (b2) is preferably from the viewpoint of the strength of the molded article. Is 50% by weight or less, more preferably 20% by weight or less.

The polyester thermoplastic elastomer (C) is an aromatic dicarboxylic acid or its alkyl ester, an aliphatic diol having 2 to 12 carbon atoms or an alicyclic diol having 2 to 12 carbon atoms, and a weight average molecular weight of Polyester / polyether type which is a polymer derived from 400 to 6000 polyalkylene ether glycol, aromatic dicarboxylic acid or its alkyl ester, and aliphatic diol having 2 to 12 carbons or 2 to 12 carbons Polyester / polyester type which is a polymer derived from an alicyclic diol, a polyester composed of an aliphatic or alicyclic dicarboxylic acid and an aliphatic diol, or a polyester composed of an aliphatic lactone or an aliphatic monoolcarboxylic acid There is.

As the aromatic dicarboxylic acid, for example,
Examples thereof include terephthalic acid, isophthalic acid, phthalic acid, and 2,6-naphthalenedicarboxylic acid.
More than one species can be used. Preferred are terephthalic acid and 2,6-naphthalenedicarboxylic acid. Examples of the alkyl ester of aromatic dicarboxylic acid include dimethyl esters such as dimethyl terephthalate, dimethyl isophthalate, dimethyl phthalate and 2,6-dimethyl naphthalate, and one or more of them can be used. . Preferred are dimethyl terephthalate and 2,6-dimethyl naphthalate.

Examples of the aliphatic diol having 2 to 12 carbon atoms or the alicyclic diol having 2 to 12 carbon atoms include, for example, ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,4-cyclohexane. Examples thereof include diol and 1,4-cyclohexanedimethanol, and these can be used alone or in combination of two or more. Preferably 1,4-butanediol,
It is ethylene glycol.

Examples of the polyalkylene ether glycol having a weight average molecular weight of 400 to 6000 include polyethylene glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, a copolymer of ethylene oxide and propylene oxide, and ethylene oxide. A copolymer of tetrahydrofuran can be used. Preferred is polytetramethylene ether glycol.

As the aliphatic dicarboxylic acid, for example,
Examples thereof include succinic acid, oxalic acid, adipic acid and sebacic acid. Examples of the alicyclic dicarboxylic acid include 1,4-
Examples thereof include cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and dicyclohexyl-4,4'-dicarboxylic acid. These may be used alone or in combination of two or more. As the aliphatic lactone, for example,
ε-caprolactone may be mentioned, and as the aliphatic monoolcarboxylic acid, for example, ω-oxycaproic acid may be mentioned.

The polyester-based thermoplastic elastomer (C) is produced by esterification reaction or transesterification followed by polycondensation reaction, and a known production method is used.

The thermoplastic polyurethane elastomer (D) is a polymer derived from diisocyanate, glycol having 2 to 20 carbon atoms, and polyol having a molecular weight of 400 to 6000. Examples of the diisocyanate include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,
Known examples include 4'diphenylmethane diisocyanate and hexamethylene diisocyanate. As the glycol having 2 to 20 carbon atoms, for example,
Examples thereof include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol and bisphenol A. As the polyol having a molecular weight of 400 to 6000, for example, polyalkylene ether glycol, polyalkylene adipate, polycaprolactone, polycarbonate is used, and for example, polyethylene glycol, polypropylene ether glycol,
Polytetramethylene ether glycol, polyhexamethylene ether glycol, poly ε-caprolactone,
An example is poly β-propiolactone.

The thermoplastic polyurethane elastomer (D) is produced by polyaddition reaction of diisocyanate, glycol having 2 to 20 carbon atoms, and polyol having a molecular weight of 400 to 6000, and a known production method is used.

Polyamide thermoplastic elastomer (E)
Is a polymer derived from a polyamide and a polyol having a molecular weight of 400 to 6000. Examples of polyamides include nylon 6, nylon 66, nylon 11, and nylon 12. Molecular weight is 400-6
As the 000 polyol, polyalkylene ether glycol, polyalkylene adipate, polycaprolactone, polycarbonate, etc. are used.
Examples thereof include polyethylene glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, poly ε-caprolactone, and poly β-propiolactone.

Polyamide thermoplastic elastomer (E)
Is produced by subjecting a polyamide to a polycondensation reaction with a polyol having a molecular weight of 400 to 6000 and a dicarboxylic acid, and a known production method is used.

Among the above-mentioned thermoplastic elastomers, the olefin-based thermoplastic elastomer (A) and the styrene-based thermoplastic elastomer (B) are preferably used from the viewpoints of cost and mechanical strength.

The melt flow rate (MFR) of the thermoplastic elastomer is preferably 0.1 to 200 g / 10 minutes, more preferably 1 to 100 g / 10 minutes.
If the MFR is too low, the melt moldability of the thermoplastic elastomer powder of the present invention may be poor, and if it is too high, the strength of the resulting molded article may be poor. In addition, MF
R is measured according to JIS K-7210 (1976) under the conditions of a temperature of 230 ° C. and a load of 21.18N.

Styrenic thermoplastic elastomer (B),
The polyester thermoplastic elastomer (C), the polyamide thermoplastic elastomer (E), and the polyvinyl chloride thermoplastic elastomer (F) may contain a polyolefin resin and / or a polyolefin rubber. By containing the polyolefin resin and / or the polyolefin rubber, the moldability, strength, and heat resistance of the molded product can be adjusted.

The thermoplastic elastomer may contain a rubber-like polymer such as natural rubber, chloroprene rubber, epichlorohydrin rubber and acrylic rubber.

Thermoplastic elastomers include mineral oil-based softeners, antioxidants (phenolic, sulfur-based, phosphorus-based, amine-based, etc.), weather-resistant stabilizers, antistatic agents, pigments, metal soaps,
Various additives such as wax, antifungal agent, antibacterial agent, filler and foaming agent may be contained.

When two or more kinds of components are blended as a thermoplastic elastomer, or when another component is blended with a thermoplastic elastomer, the components may be cold blended by using a tumble mixer or the like. Alternatively, melt kneading may be performed using a single-screw extruder, a twin-screw extruder, a kneader, a roll, a Banbury mixer, or the like. When melt-kneading, all the components to be kneaded may be melt-kneaded together, or some components may be kneaded and then unselected components may be added and melt-kneaded.

The average particle diameter of the thermoplastic elastomer powder is 30 to 1000 μm, preferably 100 to 1000 μm.
600 μm, more preferably 200 to 500 μm
Is. If the particle size is too large, it may be difficult to control the wall thickness of the molded body produced by the powder molding method to be thin. If the average particle size is too small, the fluidity of the powder may decrease. The average particle size of the thermoplastic elastomer powder is JIS Z-8801 (19
76) according to the sieving method using a standard sieve.

As a method for obtaining a thermoplastic elastomer powder having an average particle size of 30 to 1000 μm, for example, as described in JP-A-2000-344962, a freeze pulverization method, a strand cut method, a die face cut method. A known method such as a solvent treatment method is used. The polyurethane-based thermoplastic elastomer (D) and the vinyl chloride-based thermoplastic elastomer (F) are
It can also be obtained by polymerization such as suspension polymerization.

The silicone rubber used in the silicone rubber powder used in the present invention is a crosslinked polyorganosiloxane. Polyorganosiloxane produced by a known method is treated with a peroxide, sulfur, γ ray or the like. It is crosslinked and solidified at 25 ° C. The crosslinked polyorganosiloxane may contain an additive such as a filler or a wetting agent, and examples of the filler include silica,
Diatomaceous earth, aluminum hydroxide, magnesium hydroxide,
Examples thereof include calcium carbonate, titanium oxide, talc, clay, mica, montmorillonite, bentonite, carbon black and the like.

The average particle size of the silicone rubber powder is
The thickness is 0.1 to 10 μm, preferably 0.2 to 7 μm, and more preferably 0.3 to 5 μm. If the average particle size is too small or too large, the powder fluidity of the resin powder may not be sufficiently improved.

The average particle size of the silicone rubber powder is obtained by observing the silicone rubber powder with an electron microscope at a magnification of 2000 to 5000 times, arbitrarily measuring the diameter of 50 silicone powders, and averaging the number thereof. More demanded.

As a method for obtaining a silicone rubber powder having an average particle diameter of 0.1 to 10 μm, for example, a method of spraying a thermosetting liquid silicone rubber composition in hot air to cure it (Japanese Patent Laid-Open No. 59-59). No. 68333), a method of dispersing a thermosetting liquid silicone rubber composition in water and curing it (Japanese Patent Laid-Open Nos. 62-243621 and 63-70558), and known methods. Used. Examples of the product include Trefill E series manufactured by Toray Dow Corning Silicone Co., Ltd.

The resin powder of the present invention has an average particle size of 30.
-1000 μm thermoplastic elastomer powder 1
00 parts by weight and 0.1 to 10 parts by weight of a silicone rubber powder having an average particle size of 0.1 to 10 μm are dry-blended. The dry blending amount of the silicone rubber powder is 100 parts by weight of the thermoplastic elastomer powder having an average particle diameter of 30 to 1000 μm.
Preferably 0.3 to 7 parts by weight, more preferably 0.5 to
5 parts by weight. If the dry blending amount of the silicone rubber powder is too small, the powder fluidity of the resin powder and the releasability from the mold may not be sufficiently improved, and if the dry blending amount is too large, the mechanical properties of the obtained molded product may be poor. It may decrease.

Granular thermoplastic elastomer powder having an average particle size of 30 to 1000 μm and an average particle size of 0.1 to
The method of dry blending with the silicone rubber powder having a thickness of 10 μm is not particularly limited, and examples thereof include a method of blending using a known powder / granular mixer such as a tumble mixer or a Henschel mixer. Among these, the method using a Henschel mixer is preferable from the viewpoint of uniformity of mixing.

The resin powder of the present invention can be applied to various powder molding methods such as powder slush molding method, fluidized dipping method, electrostatic coating method, powder spraying method and rotational molding method, press molding method, extrusion molding method, injection molding method. And the like can be used as the material. Among these, the powder molding method is suitable.

For example, the method for producing a molded body by the powder slush molding method is carried out by a method comprising the following first to fifth steps. First step: a step of supplying resin powder onto the molding surface of the mold heated above the melting temperature of the thermoplastic elastomer Second step: heating the powder of the resin powder on the molding surface of the first step for a predetermined time Then, the step of fusing the powders whose surfaces are melted to each other Third step: The step of recovering the resin powder that has not been fused after a predetermined time has passed in the second step Fourth step: Melting, if necessary The step of further heating the mold on which the resin powder has been placed Fifth step: After the fourth step, the step of cooling the mold and removing the molded body formed thereon from the mold

In the powder slush molding method, the mold temperature is usually 160 to 320 ° C., and the mold heating method is a gas heating furnace system, a heat carrier oil circulation system, a heat carrier oil or a heat fluidized sand. The immersion method, high frequency induction heating method, etc. are used.

A foaming agent may be blended in the resin powder of the present invention, and a foamed molded article can be produced by foaming the powder-molded molded article. As the foaming agent, a thermal decomposition type foaming agent is usually used, and examples thereof include azo compounds such as azodicarbonamide, 2,2′-azobisisobutyronitrile and diazodiaminobenzene; benzenesulfonylhydrazide, benzene-1, Sulfonyl hydrazide compounds such as 3-sulfonyl hydrazide and p-toluene sulfonyl hydrazide; N, N'-dinitrosopentamethylene tetramine, nitroso compounds such as N, N'-dinitroso-N, N'-dimethyl terephthalamide, terephthalazide, etc. Azide compounds of the above; carbonates such as sodium bicarbonate, ammonium bicarbonate, ammonium carbonate and the like. The foaming agent may be melt blended with the thermoplastic elastomer powder or may be dry blended with the thermoplastic elastomer powder.

It is also possible to laminate another layer on one side and / or both sides of the molded body made of the resin powder of the present invention to form a multilayer molded body. Examples of the other layer include a synthetic resin layer and a metal layer, and examples of the synthetic resin forming the synthetic resin layer include:
Examples thereof include polyolefin resins such as polypropylene and polyethylene, thermoplastic elastomers, polyamide resins, ethylene-vinyl alcohol copolymers, polyester resins, ABS (acrylonitrile-butadiene-styrene copolymers), adhesive resins, and the like. These layers may be foamed.

The molded product of the present invention can be optimally used for automobile interior parts such as instrument panels, door trims, console boxes and pillars.

[0057]

EXAMPLES The present invention will be described in detail below with reference to examples. The physical properties were evaluated by the following methods. [1] Evaluation method Melt flow rate (MFR) According to JIS K-7210 (1976), a load of 21.
It was measured at 18N. The average particle diameter of the thermoplastic elastomer powder was measured by a sieving method using a standard sieve according to JIS Z-8801 (1976). Average particle size of silicone rubber powder The silicone rubber powder was observed with an electron microscope at a magnification of 2000 to 5000 times, and the diameters of 50 silicone powders were arbitrarily measured, and the average particle size was obtained.

Powder flowability of resin powder After 100 cm ³ of resin powder was put into the funnel of the bulk specific gravity measuring device described in JIS K-6722 (1977), the damper was opened until all the powder came out of the funnel. Was measured. Releasability of the powder slush molded product The end of the molded product fused to the mold after the powder slush molding was peeled off so that the width of the fused part of the molded product was 10 cm. Next, while keeping the direction of force horizontal (180 °) to the mold surface, the molded body was pulled at a speed of 100 mm / min, and the force when the molded body was peeled from the mold was measured.

Example 1 [Production of thermoplastic elastomer powder, evaluation of powder fluidity] Propylene-ethylene copolymer resin (manufactured by Sumitomo Chemical Co., Ltd., PPD200, ethylene unit content 5% by weight, MFR = 220 g / 10) Min (temperature 230 ℃) 10
0 part by weight, hydrogenated product of styrene-butadiene-styrene copolymer (JSR Corporation, Dynaron 2321P, M
FR = 10 g / 10 min (temperature 230 ° C.) 100 parts by weight and ethylene-propylene rubber (Supreme SPO V0141, manufactured by Sumitomo Chemical Co., Ltd., propylene unit content 27 wt%, MFR = 1 g / 10 min (temperature 190
)) 50 parts by weight using a twin-screw kneader (TEX-44HCT, manufactured by Japan Steel Works, Ltd.) at a temperature of 170 ° C. to knead to prepare a composition, which is cut with a cutting machine. To obtain pellets. The obtained pellet was -1 using liquid nitrogen.
After cooling to 20 ° C, crushing while keeping the cooling state,
The crushed product is Tyler standard sieve 42 mesh (opening 355μ
m × 355 μm) to obtain a thermoplastic elastomer powder. The average particle size of the powder is 215μ
It was m. Next, to 100 parts by weight of this thermoplastic elastomer powder, 2 parts by weight of silicone rubber powder (Toray Dow Corning Silicone Co., Ltd., Trefil E-605, average particle size 2 μm) were blended with a Henschel mixer, and the resin was added. I got powder. Table 1 shows the results of evaluation of the powder fluidity of the obtained resin powder.

[Manufacture of Powder Molded Product, Evaluation of Releasability] Nickel mold (12 cm × 12 cm ×) having a grain pattern on the surface
(3 mm thickness) was placed on an iron plate (hot plate) heated to 290 ° C. and heated, and the temperature of the molding surface (surface having a grain pattern) of the mold was adjusted to 260 ° C. 500 g of resin powder was sprinkled on the molding surface of the mold to melt the resin powder, and the resin powders were fused to each other. After 10 seconds, the thermoplastic elastomer powder which was not fused was blown off. Then, the mold was further placed on the above-mentioned heated iron plate for 60 seconds, and then the mold was water-cooled to obtain a molded body. The releasability of the obtained powder slush molded product was evaluated. The production of the powder compact and the evaluation of the releasability were repeated 10 times to examine the change in the releasability. The results are shown in Table 1.

Comparative Example 1 Except that a resin powder containing 2 parts by weight of alumina silica powder having an average particle diameter of 3 μm (alumina silica, JC-30 manufactured by Mizusawa Chemical Co., Ltd.) per 100 parts by weight of the thermoplastic elastomer powder was used. The procedure was as in Example 1.
The results are shown in Table 1.

Comparative Example 2 1 part by weight of silica powder having an average particle size of 50 nm (silica, OX-50 manufactured by Degussa) and alumina silica powder having an average particle size of 3 μm (100% by weight of Mizusawa Chemical Co., Ltd.) per 100 parts by weight of the thermoplastic elastomer powder. Made alumina silica, JC
The same procedure as in Example 1 was carried out except that a resin powder containing 1 part by weight of −30) was used. The results are shown in Table 1.

Comparative Example 3 The procedure of Example 1 was repeated except that only the thermoplastic elastomer powder was used as the resin powder. The results are shown in Table 1.

[0064]

[Table 1]

[0065]

EFFECTS OF THE INVENTION According to the present invention, a molded product having excellent mold releasability from a mold can be obtained, and a resin powder having excellent powder fluidity can be provided. Furthermore, the resin powder can be powder molded. It was possible to provide a molded product obtained by the method and a method for producing the molded product by powder molding. The powder is
It is especially suitable for powder molding method, and because it has excellent productivity and non-staining property on the surface of molded products, it has moldings such as skin cover materials for automobile interior parts, protective covers for cameras and calculators, etc. with patterns such as leather grain and stitches on the surface. Used as a body.

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Claims (4)

[Claims] 1. A thermoplastic elastomer powder having an average particle size of 30 to 1000 μm and 100 parts by weight of a silicone rubber powder having an average particle size of 0.1 to 10 μm.
Resin powder obtained by dry blending 1 to 10 parts by weight. 2. The resin powder according to claim 1, wherein the thermoplastic elastomer powder according to claim 1 is an olefin-based and / or styrene-based thermoplastic elastomer powder. 3. A molded body obtained by powder molding the resin powder according to claim 1 or 2. 4. A method for producing a molded body obtained by powder-molding the resin bower according to claim 1.