| 摘要 |
Flame-retardant and/or self-extinguishing foamed cellular articles, based on alkenyl aromatic polymers, are prepared by subjecting the foamed polymer articles containing an organic bromine-containing compound as flameproofing agent to high energy ionizing radiation in the presence of oxygen or air. Homopolymers of styrene, vinyl toluene, vinyl xylene, ar-ethyl vinyl benzene, ar-chlorostyrene or a -methyl styrene; copolymers of two or more of these monomers; and copolymers of one or more such monomers with other olefinic compounds, e.g. acrylonitrile, methyl methacrylate and divinyl benzene are specified. Exemplified bromine-containing compounds are 1,1,2,2-tetrabromoethane, 1,2-dibromo-1,1,2,2-tetrachloroethane, 1,2-dibromo-1-phenylethane, pentabromoethane, 1,2,3,4-tetrabromobutane, 1,2,3-tribromopropane, 1,2,4-tribromobutane, tetrabromopentane, 1,2-di(dibromomethyl) benzene, monochloropentabromocyclohexane and tris-(2,3-dibromopropyl)-phosphate.ALSO:Flame-retardant and/or self extinguishing foamed cellular articles, based on alkenyl aromatic polymers, are prepared by subjecting the foamed polymer articles containing an organic bromine-containing compound as flame-proofing agent to high energy ionizing radiation in the presence of oxygen or air. The polymer may be made cellular either by dissolving under pressure a normally gaseous agent, e.g. methyl chloride or dimethyl ether, in the polymer and releasing the pressure as by extrusion, or by heating discrete particles of the polymer containing a volatile organic liquid, e.g. pentane or hexane, in a porous mould. Homopolymers of styrene, vinyl toluene, vinyl xylene, ar-ethylvinylbenzene, ar-chlorostyrene or a -methyl styrene; copolymers of two or more of these monomers; and copolymers of one or more such monomers with other definite compounds, e.g. acrylonitrile, methyl methacrylate and divinyl benzene are specified. Examplified bromine-containing compounds are 1, 1, 2, 2- tetrabromoethane, 1, 2- dibromo- 1, 1, 2, 2- tetrachloroethane, 1, 2- dibromo- 1- phenylethane, pentabromoethane, 1, 2, 3, 4- tetrabromobutane, 1, 2, 3-tribromopropane, 1, 2, 4- tribromobutane, tetrabromopentane, 1, 2- di- (di bromomethyl) benzene, monochloropentabromocyclohexane and tris- (2, 3- di bromopropyl)- phosphate. |
