Polyplastics Co., Ltd.

Noriyuki Sugiyama

Kaoru Yamamoto

Mitsuhiro Mochizuki

Hiroyuki Hase

Makoto Kamiya

Hiroyuki Miyaji

Hiroko Iizuka

Arisa Chisoku

A polyoxymethylene composition is reduced in mold fouling, undergoes little discoloration in molten-state residence within the cylinder of a molding machine, has improved moldability, and is reduced in formic acid generation, when compounded with a sterically hindered phenolic antioxidant (a), of a polyamide (b), at least one metal compound selected among oxides and carbonates of magnesium or calcium (c) and a boron compound (d).

Polyoxymethylene compositions

Polyoxymethylene compositions exhibiting improved heat stability and reduced formation of mold depositions during molding are usefully employed to form molded articles used as parts for electrical or electronic equipment since such parts experience few malfunctions due to formic acid generated from the composition. The preferred composition includes a blend of 100 parts by weight of polyoxymethylene resin with (a) 0.01 to 5.0 parts by weight of an antioxidant, (b) 0.01 to 5.0 parts by weight of a melamine-formaldehyde polycondensate, and (c) 0.001 to 10 parts by weight of at least one metallic compound selected from magnesium oxide, magnesium carbonate, and calcium oxide.

Polyoxymethylene composition and molded article thereof

Polyoxymethylene composition

Polyoxymethylene molding compositions include a polyoxymethylene base resin and contain, based upon the weight of the polyoxymethylene base resin, between 0.01 to 5% by weight of a hindered phenolic antioxidant, and between 0.01 to 5% by weight of an amine polymer having a molecular weight of at least 1000 and comprised essentially of structural units of the following formula (1): ##STR1## wherein R represent a hydrogen atom, an alkyl group, a phenyl group, an alkyl-substituted phenyl group, an NH.sub.2 group directly bonded to the carbon atom, or --X--NH.sub.2 -- where X represents an alkylene group, a carbonyl group, a carboxyalkylene group, an alkyleneoxycarbonylalkyl group, a phenylene group, an alkyl-substituted phenylene group, an amido group or an alkyleneamido group.

Polyoxymethylene compositions containing amine polymer having pendant

A polyacetal resin composition is prepared by melt-kneading a polyacetal resin (A) (99 to 40 wt. %) with a thermoplastic polyurethane (B) (1 to 60 wt. %) in the presence of a polyisocyanate compound, a polyisothiocyanate compound or a modification thereof (C) in an amount of 0.1 to 10 wt. % based on the total of A and B.

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Shizuoka, Japan

Noriyuki Sugiyama