JPH0550539B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin composition, and more particularly to a styrenic resin composition suitable for producing molded articles having good impact resistance, flexibility, etc. Conventionally, solid rubber has been blended into thermoplastic resins such as polystyrene in order to impart impact resistance, flexibility, and the like. Moldings made of thermoplastic resin blended with solid rubber exhibit excellent impact resistance and flexibility, but when blending rubber with thermoplastic resin, the rubber to be blended is solid, so it must be handled carefully. There was a problem with the mixing operation. Therefore, it has been proposed to incorporate liquid polybutadiene, which is easy to handle and has similar properties improving effects, in place of solid rubber. However, liquid polybutadiene has poor compatibility with thermoplastic resins and causes bleeding phenomena, so that the expected results have not been obtained. Therefore, the inventor of the present invention has excellent operability and handling.
In addition, as a result of intensive research to develop a thermoplastic resin composition with good impact resistance, flexibility, etc., we discovered that the above objectives could be achieved by adding a specific copolymer to a styrene resin. The present invention was completed based on this knowledge. That is, the present invention relates to styrene resin (hereinafter referred to as (A)
It is called an ingredient. ) and a liquid butadiene-styrene copolymer having a hydroxyl group at the end (hereinafter referred to as component (B)). Various types of styrene resins can be used as the component (A) in the present invention. Specifically, polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), acrylate-styrene-acrylonitrile copolymer (ASA), chlorinated polyethylene-acrylonitrile-styrene copolymer (ACS), methacrylate- Examples include butadiene-styrene copolymer (MBS), methacrylate-styrene copolymer (MS), styrene-acrylonitrile copolymer (SA), and mixtures thereof. Next, component (B), a liquid butadiene-styrene copolymer having a hydroxyl group at the end, can be used regardless of the manufacturing method as long as it is a liquid butadiene-styrene copolymer having a hydroxyl group at the end. It may be a polymer, a random copolymer, or the like. The molecular weight of component (B) is usually number average molecular weight 300~
25,000, preferably about 500 to 5,000. If the molecular weight exceeds 25,000, the viscosity becomes high, which is not preferable. The content of styrene units in component (B) is preferably 1 to 50 mol%, more preferably 5 to 30 mol%. If the styrene unit content is less than 1 mol%, a bleeding phenomenon occurs, and if it exceeds 30 mol%, the viscosity is high and it is difficult to handle like solid rubber. Such component (B) can be produced by various methods, for example, butadiene and styrene are mixed in isopropyl alcohol as a solvent in the presence of 50% hydrogen peroxide in an autoclave at 80 to 150°C;
The reaction may be carried out for about 30 to 200 minutes. The amount of component (A) and component (B) in the present invention is not particularly limited, but usually 1 to 30 parts by weight, preferably 5 to 20 parts by weight of component (B) per 100 parts by weight of component (A). Department. If it is less than 1 part by weight, good properties cannot be obtained, and if it exceeds 30 parts by weight, a bleeding phenomenon occurs.
Undesirable. The composition of the present invention basically consists of component (A) and component (B), but if necessary, various additives such as fillers, stabilizers, colorants, flame retardants, ultraviolet absorbers, antioxidants, and electrostatic charges may be added. Inhibitors etc. can be added. Examples of the filler include organic fillers such as wood flour, paper, cloth, and fruit powder, and inorganic fillers such as calcium carbonate, kaolin, clay, talc, silica, and mica. Also, as stabilizers, lead, cadmium, zinc, phosphorous acid or stearic acid,
Examples include salts such as barium, and colorants include reaction products of poorly soluble azo dyes with calcium or magnesium, cadmium yellow, chrome yellow, phthalocyanine blue, and titanium white. Examples of the flame retardant include inorganic flame retardants such as antimony oxide, zircon oxide, and barium metaborate, and organic flame retardants such as phosphate ester. Furthermore, UV absorbers include benzophenone types such as 2-hydroxybenzophenone, triazole types, salicylic acid derivatives, and acrylonitrile derivatives, and antioxidants include 2,6-di-t-butyl-p - Phenol-based agents such as cresol, antistatic agents include surfactants, and the like. The thermoplastic resin composition of the present invention comprises component (A) and
It is manufactured by blending the component (B) and, if necessary, the additives mentioned above and kneading. The kneading may be carried out by a conventional method, for example, using a Banbury mixer at a temperature of 50 to 350°C, preferably 100 to 250°C, for 1 to 120 minutes, preferably
You can do this for 10 to 100 minutes. The thermoplastic resin composition thus obtained can be molded by various molding methods, and the molded product obtained has extremely excellent impact resistance and flexibility. Therefore, the thermoplastic resin composition of the present invention is extremely useful as a material for resin molded articles. Next, the present invention will be explained in detail with reference to examples. Examples 1 to 4 and Comparative Examples 1 to 3 Predetermined amounts of the components shown in Table 1 were blended and kneaded at a rotation speed of 60 rpm using a kneader (Laboplast Mill) under the kneading conditions shown in Table 1. A thermoplastic resin composition was obtained. A test piece of 150 mm x 300 mm x 2 mm was prepared from the obtained composition using a 200 Kg·f/cm ² press molding machine, and the Izod impact strength and Rockwell hardness of this test piece were evaluated. The results are shown in Table 1. Comparative Examples 4 to 6 Component (A) shown in Table 1 was molded to prepare test pieces in the same manner as in Example 1, and evaluations were performed. The results are shown in Table 1. Comparative Example 7 A composition was obtained in the same manner as in Example 1, except that a liquid butadiene-styrene copolymer (having no terminal hydroxyl group) was used as the component (B) in Example 1, and a test piece was prepared. and conducted an evaluation. The results are shown in Table 1. 【table】

Claims (1)

[Scope of Claims] 1. A thermoplastic resin composition comprising a styrene resin and a liquid butadiene-styrene copolymer having a terminal hydroxyl group. 2. The composition according to claim 1, wherein the liquid butadiene-styrene copolymer having a hydroxyl group at the terminal has a number average molecular weight of 300 to 25,000. 3 The content of styrene units in the liquid butadiene-styrene copolymer having a hydroxyl group at the end is 1 to 50
A composition according to claim 1, wherein the composition is in mol %. 4. The composition according to claim 1, wherein the amount of the liquid butadiene-styrene copolymer having a hydroxyl group at the terminal is 1 to 30 parts by weight per 100 parts by weight of the styrene resin.