Kureha Kagaku Kogyo Kabushiki Kaisha

Masanori Oota

Haruhiko Yusa

Kazuo Takahashi

Katsumi Suzuki

Hideyuki Hashizume

Takayuki Katto

Yoshikatsu Satake

Hitoshi Takita

Haruki Isaka

Humio Akutsu

Seiji Usami

Katumi Suzuki

Susumu Chubachi

An impact-resistant thermoplastic resin composition having excellent transparency and appearance properties which comprises (A) a butadiene-styrenemethyl methacrylate-alkyl acrylate graft copolymer obtained by postpolymerization of styrene, methyl methacrylate and an alkyl acrylate to a latex comprising a butadiene homopolymer rubber or a butadiene-styrene copolymer rubber comprising mainly butadiene and having an average particle diameter of 0.1 to 0.5 .mu., and (B) a methyl methacrylate-styrene copolymer. This composition has quantitative limitation.

Thermoplastic resin composition

A latex of a highly crosslinked butadiene rubber polymer comprising not less than 50% of butadiene, 1.0 to 10% of a crosslinking agent and a remainder of an ethylenically unsaturated monomer copolymerizable with butadiene, and having a particle size of 600 to 3,000 .ANG. and a degree of swelling of not greater than 7 is obtained by one or more stages of emulsion polymerization. By polymerizing 15 to 30 parts of a monomer mixture of an alkyl methacrylate, an aromatic vinyl monomer, and optionally a crosslinking agent and an unsaturated nitrile in the presence of 85 to 70 parts of the rubber polymer, a graft copolymer is obtained. A composition comprising 2 to 40% of this graft copolymer and 98 to 60% of a vinyl chloride resin possesses high impact resistance coupled with improved stress-whitening resistance, which properties cannot be easily obtained at the same time in conventional resin compositions.

Vinyl chloride resin composition

Modified titanium oxide is prepared by polymerizing a mixture of vinyl chloride and a carboxylic monomer such as 10-undecenoic acid in the presence of titanium oxide. The thus obtained, modified titanium oxide is mixed with a vinyl chloride resin, typically, polyvinyl chloride to give a vinyl chloride resin composition having an improved weatherability and being substantially free of serious drawbacks accompanying the addition of conventional titanium oxide such as plating out during extrusion and decrease in extrusion throughput.

A process for producing a graft-polymer comprises adding an aqueous solution of a salt of a strong acid and a monovalent strong base, which solution has been adjusted to a pH value of 8 to 13, to a rubber latex containing diene rubber particles and a fatty acid soap as an emulsifying agent to coagulate the above mentioned rubber particles, and thereafter adding a vinyl monomer to the latex containing the coagulated rubber particles to graft-polymerize the vinyl monomer. According to this process, the formation of rubber masses and macroparticles during the coagulation is reduced and a rubber latex containing rubber particles having a narrow range of particle size distribution is obtained. When a graft-copolymer obtained by using the latex is blended with thermoplastic resins such as vinyl chloride resins, the impact resistance of the thermoplastic resins can be remarkably improved without impairing their transparency and gloss.

Process for producing a graft-copolymer and blends therewith

Graft-copolymers for improving impact strength comprising a relatively large quantity of an elastomeric trunk polymer, such as acrylonitrile/styrene/butadiene resins and methyl methacrylate/styrene/butadiene resins, have some undesirable powder characteristics, for example, poor fluidity and an easily blocking property. However, by blending a graft-copolymer of this type with a graft-copolymer comprising a relatively small quantity of an elastomeric trunk polymer in slurry form or dry state, it is possible to obtain a graft-copolymer blend with improved powder characteristics without significantly lowering the effect of improving the impact strength of the former graft-copolymer. The graft-copolymer blend thus obtained, when blended with a hard resin such as polyvinyl chloride, provides a resin composition with high impact strength.

Powdery graft-copolymer composition

An alkyl acrylate copolymer comprises 60 to 99.5 wt. % of a C.sub.2 -C.sub.12 alkyl acrylate component, 0.1 to 10 wt. % of a polyfunctional monomer component having one or more conjugated double bond and one or more non-conjugated double bond and 0 to 35 wt. % of a comonomer component. A thermoplastic resin composition comprises 97 to 70 wt. parts of a rigid thermoplastic resin and 3 to 30 wt. parts of the alkyl acrylate copolymer.

Thermoplastic resin composition comprising a rigid thermoplastic resin

A resinous composition having fire retardance, impact resistance and easy workability is obtained by blending (1) about 80 to 30 parts by weight of an ABS resin with (2) about 20 to 70 parts by weight of (i) a vinyl chloride resin compound comprising 100 to 5 parts by weight of a copolymer resin consisting essentially of 0.5 to 40% by weight of a higher alkyl vinyl ether and 99.5 to 60% by weight of vinyl chloride and (ii) 0 to 95 parts by weight of a polyvinyl chloride resin.

Fire retardant resinous compositions

Vinyl chloride resin composition having excellent impact resistance, weather resistance and processability which comprises a vinyl chloride resin and a multicomponent resin blended therewith, said multicomponent resin being prepared by (1) graft polymerizing acrylonitrile, and a vinyl monomer which is methyl methacrylate and/or styrene, and a cross-linking agent onto cross-linked copolymer rubber obtained by emulsion-polymerizing an alkyl acrylate, butadiene and a cross-linking agent or onto a cross-linked terpolymer rubber obtained by emulsion-polymerizing an alkyl acrylate, butadiene, methyl methacrylate and a cross-linking agent and (2) further graft polymerizing thereonto an alkyl methacrylate and a cross-linking agent. Quantitative limitations are included.

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Iwaki, Japan

Masanori Oota