JPS63248837A - Production of matte resin moldings - Google Patents

Abstract

PURPOSE:To obtain a matte moldings useful in an office automation (OA) equipment, etc., by heat-treating moldings obtained by using a thermoplastic polymer composition consisting of acrylonitrile-styrene based polymer and specific rubber component at a definite temperature or above. CONSTITUTION:A thermoplastic polymer composition composed of (A) 70-95wt.% acrylonitrile-styrene based polymer and (B) 5-30% rubber component crosslinked with a crosslinking agent containing partially or wholly unsaturated nitrile-conjugated diene based copolymer rubber (preferably copolymer rubber consisting of 10-50% unsaturated nitrile and 90-50% conjugated diene) is used to afford moldings which are heat-treated at >=(T-10) deg.C (T is heat distortion temperature of the above-mentioned thermoplastic polymer composition) to provide the matte moldings.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a thermoplastic resin molded article with an excellent matte surface. Regarding method a.

(Prior art and problems to be solved by the invention) Various thermoplastic resins are used in OA equipment, homes, etc. It is used in large quantities as housings for L equipment and interior materials for automobiles. These molded objects are sometimes required to have a matte appearance in order to match the color of other devices and to provide an elegant visual impression.

To meet these demands, attempts have been made to add inorganic fillers, rubber blends, etc., but the matting effect is not sufficient. In order to obtain a molded product with a superior matte surface, the inventors of the present invention conducted extensive research to obtain a molded product made of a resin composition consisting of a thermoplastic resin and a rubber component crosslinked with a crosslinking agent at a specific temperature. It was discovered that an excellent matte molded product could be obtained by heat treatment, and the present invention was completed.

(Means for Solving the Problems) Thus, according to the present invention, 70 to 95% by weight of acrylonitrile-styrene resin and unsaturated nitrile-conjugated diene polymer rubber are used in part or in whole, and a crosslinking agent is used. Thermoplastic resin composition Wt consisting of crosslinked rubber component 5 to 30i [amount T] - Molded bar used (T-10) t: Heat treatment at a temperature above (hereinafter, represents the heat distortion temperature of the resin composition) Provided is a method for producing a matte resin molded body characterized by the following.

The acrylonitrile-styrene resin used in the present invention is a copolymer resin of acrylonitrile and styrene or α-methylstyrene, which is commonly referred to as a human S resin, and a copolymer resin of acrylonitrile and styrene or α-methylstyrene, which is usually referred to as an ABS resin, and a resin that has ASS information on dispersed polybutadiene rubber particles, which is referred to as an ABS resin. Death-grafted impact resistant resin [e.g.
Polymer Data No. Ndpook Application Edition ABS Resin
Pages 139-44 (Published by Baifukan on January 30, 1985)
], weather resistance/@WI impact resistance made of acrylic rubber called AAS or ASA resin partially grafted with Ac'J ronitrile styrene copolymer↑GPDM rubber called ABS resin This includes weather-resistant and impact-resistant resins partially grafted with acrylonitrile-styrene copolymers.

The thermoplastic side fat composition used in the present invention is a mixture of the above acrylonitrile-styrene resin and an unsaturated nitrile-conjugated diene polymer rubber as a rubber component, or this rubber and another rubber.

The unsaturated nitrile-conjugated diene polymer rubber used in the present invention is preferably a copolymer rubber containing 10 to 50% by weight of unsaturated nitrile and 90 to 50% by weight of conjugated diene. Examples of unsaturated nitriles include acrylonitrile and methacrylonitrile; examples of conjugated dienes include 1,3-butadiene and 2-butadiene.
．． Examples include 3-dimethylbutadiene, isoprene, and 1,3-pentadiene.

There is no problem in replacing a part of the conjugated diene with another monomer copolymerizable with the above-mentioned monomers as long as the gist of the present invention is not impaired. Such monomers include aromatic vinyl monomers such as styrene and α-methylstyrene, fulkylacrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate, methoxymethyl acrylate, and methoxyethyl acrylate. , ethoxyethyl acrylate,
alkoxyalkyl acrylates such as butoxyethyl acrylate, methoxyethoxyethyl acrylate,
Unsaturated carbogenic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, or their alkali metal salts, ammonium salts, cyanomethyl (meth)acrylate, 3-cyanopropyl (meth)acrylate, 4-cyanobutyl (meth)acrylate, etc. Examples include (meth)acrylic acid cyanoconverted alkyl esters, but monomers other than the above-mentioned examples can also be used as long as they can be copolymerized with unsaturated nitriles and conjugated dienes. Examples of the unsaturated nitrile-conjugated diene polymer rubber include acrylonitrile-butadiene copolymer rubber, acrylonitrile-isoprene copolymer rubber,
Examples include acrylonitrilubutazene-isodelene copolymer rubber and acrylonitrilubutadzuene-acrylic acid copolymer rubber.

Other rubbers that can be used in combination with the unsaturated 2) IJ sulfate-based polymer rubber used in the present invention include vulcanizing agents commonly used in the rubber industry, such as sulfur vulcanization systems and organic peroxide vulcanization systems. Any rubber that can be sulfurized with polybutadiene rubber, styrene-butadiene copolymer rubber (Random, Glock),
Conjugated diene polymer rubbers such as natural rubber, polyisograne rubber, polychloroglene rubber, and their hydrides, E
An example is PDM. When unsaturated nitrile-conjugated diene polymer rubber and other rubbers mentioned above are used together as a rubber component, the rubber component contains at least 10% by weight of unsaturated nitrile-conjugated diene polymer rubber. If the amount is less than 10% by weight, the improvement in matting properties is not sufficient. More preferably it is 20 weight or more.

The rubber component is contained in the resin composition in an amount of 10μ or less, more preferably 1 to
It is desirable from the viewpoint of matting properties and impact resistance that the rubber component is dispersed as particles of 5 μm in size, and it is necessary from the viewpoint of matting that the rubber component is crosslinked with a rubber crosslinking agent. The crosslinking agent used is not particularly limited as long as it crosslinks the comb component. Usually, sulfur and/or sulfur-donating compounds (e.g. thiuram compounds such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, morpholine compounds such as morpholin disulfide), zinc oxide, magnesium oxide, zinc stearate, etc. Vulcanization aids, stearinization, vulcanization accelerators, for example, guanidine compounds such as diphenylguanidine,
Sulfur vulcanization systems using thiazole compounds such as mercaptobenzothiazole, benzothiazyl disulfide, and cyclohexylbenzothiazyl sulfenamide, and thiuram compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide;
Dicumyl peroxide, 2,5-dimethyl-2,5-
Di(t-butylperoxy)-hexane, 2,5-methyl-2,5-no(t-butylperoxy)-hexyne-3,1,3-bis(1-butylperoxy-isoprobyl)benzenato Organic peroxide vulcanization systems and the like are used. The amount of these vulcanization systems used is such that the rubber component is optically crosslinked.

The thermoplastic resin composition used in the present invention is usually prepared by mixing the above-mentioned acrylonitrile-styrene resin and a column component in the presence of a crosslinking agent for the rubber component in a conventional mixer such as a Ni-Goo or a cross-wire extruder. It is produced by using a method commonly called dynamic vulcanization, in which the rubber components are crosslinked during mixing. A preferred embodiment of the mixing is a method in which the resin and the comb component are sufficiently melted and mixed in advance, a crosslinking agent for the rubber component is added, and the mixing is continued at a temperature and for a time necessary for the resin to melt and the rubber component to crosslink. It is.

Since the mixing temperature and time for crosslinking the rubber components vary depending on the type of rubber component and the type of vulcanizing agent, it is necessary to determine all vulcanization conditions in advance through preliminary experiments. Usually, the temperature is 150 to 230°C for 5 to 30 minutes.

In general, a photochromic agent, a coloring agent, a plasticizer, a lubricant, a stabilizer, etc. are appropriately added to the resin composition used in the present invention depending on the performance of the V powder.

The thermoplastic resin composition is molded using the usual injection molding method.
Molding is performed under conditions suitable for each resin. A feature of the method of the present invention is that the matting properties are improved by heat-treating the molded product. The heat treatment of the molded body is carried out at a temperature of minus 10° C. or higher, the heat distortion temperature of the resin composition (according to JIS K7207, method A). The optimum temperature should be determined through preliminary tests depending on the shape accuracy required for the molded article, but generally a heat distortion temperature range of -5°C to +10°C is appropriate. The method of heat treatment is not particularly limited, and any method such as heated air or hot water may be used.

(Effects of the Invention) The thus obtained thermoplastic resin molded article of the present invention has an excellent matte surface and is suitable for housings of OA equipment, home appliances, etc.
It is useful as an automobile interior material, etc.

(Examples) The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. The numbers of parts and percentages used in Examples and Comparative Examples are based on weight unless otherwise specified.

Examples 1 to 3, Comparative Examples 1 to 3 AS resin (Sunrex SAN manufactured by Mitsubishi Monsando Chemical Co., Ltd.
-C) and the rubber components listed in Table 1 were mixed using a roll at 160°C. Good rotational punctures can be obtained! The crosslinking agent described above was added, mixed again until a good bank was obtained, and sheeting was performed. obtained f
cA S'fR fat/rubber component mixture and ABS m fat (
Diamond (T3001) manufactured by Mitsubishi Rayon Co., Ltd. was mixed in the proportions listed in the table using a roll at 170°C. A thermoplastic resin composition was obtained by mixing until a good rotational puncture was obtained, and after sheeting, the mixture was pelletized using an R-let molding machine.

Using an injection molding machine with a diameter of f 40 wm, the die head temperature was 220°C and the screw rotation speed was 6Or.
pm, injection pressure 50 kg/cm2, Y-zi injection speed 50 cm, length 9 tMX width 5 am
Obtain a board that is X 2m thick.9. This molded plate was heat treated with the gear open at the temperature and time listed in the table, and the gross value i JIS
Measured according to z8741.

The above results are shown in Table 1.

From Table 1, the gloss value of the ABS resin of the reference example also decreases to some extent due to heat treatment, but in Examples 1 to 3, a significant decrease in digloss value is observed due to heat treatment, and the method of the present invention significantly reduces the matte property. It can be seen that an improved molded article can be obtained.

Claims (2)

[Claims] (1) Acrylonitrile-styrene resin 70-95% by weight (2) Rubber components 5 to 5 which are partially or entirely composed of unsaturated nitrile-conjugated diene polymer rubber and crosslinked with a crosslinking agent.
A matte product characterized by heat-treating a molded article using a thermoplastic resin composition comprising 30% by weight at a temperature of (T-10)°C or higher (T represents the heat distortion temperature of the resin composition) A method for producing a resin molded body.