| 摘要 |
1431586 Polyoxymethylene compositions HOECHST AG 6 July 1973 [6 July 1972] 32412/73 Headings C3P and C3R Thermoplastic moulding compositions comprise (1) a polyoxymethylene composition comprising 99À999 to 90 weight per cent of a linear polyoxymethylene and 0À001 to 10 weight per cent of a branched or cross-linked polyoxymethylene and (2) 0À1 to 10 per cent by weight of the polymers of a modifying polymer having a molecular weight of 1000 to 1,000,000, a softening point below the crystallite melting point of the polyoxymethylene composition and a second order transition temperature of - 120 to + 30‹ C., and present in the mixture as particles of diameter 0À1 to 5 microns. The modifying polymer may be a polyethylene, copolymer of ethylene with propylene, vinyl acetate, acrylic acid or acrylic or methacrylic esters; a polybutadiene, polyisoprene or styrene / butadiene or acrylonitrile / butadiene copolymer; a vinyl, acrylic or methacrylic ester polymer; a polymer of a cyclic ether; or a polyester condensate of dicarboxylic acids with diols. The compositions may contain conventional stabilizers and examples describe moulding compositions comprising bis-(2-hydroxy - 3 - t - butyl - 5 - methylphenyl) methane and dicyandiamide together with a linear polyoxymethylene selected from acetalized formaldehyde homopolymers and copolymers of trioxane with ethylene oxide or dioxolane-1,3; branched or cross-linked polymers selected from copolymers of trioxane and ethylene oxide with butanediol diglycidyl ether or methyl glycidyl formal, photocross-linked trioxane/ ethylene oxide/methyl p-glycidyloxycinnamato copolymer, trioxane / ethylene oxide / p-glycidyloxybenzaldehyde copolymer cross-linked with hydrazine hydrate, and saponified trioxane / epichlorhydrin copolymer and trioxane / p - glycidoxynitrobenzene copolymer reacted with hydrazine hydrate cross-linked with 1,4-diazobicyclo[2,2,2]octane and 4,4<SP>1</SP>- diisocyanatodiphenylmethane; and modifying polymers selected from polyethylene; ethylene/ vinyl acetate, ethylene / ethyl acrylate, butadiene/acrylonitrile and ethylene oxide / propylene oxide copolymers; polytetrahydrofurane; polyethylene oxide and poly-2-ethylhexyl methacrylate. |
