Patent EP-2692519-A1 (EP)
IPC: C08J9/00
Filed: 2012-08-02
Abstract: Foam comprises (P) a thermoplastic polymer comprising (P1) at least one styrene copolymer which comprises (P1a) polymerized maleic anhydride units, (P1b) polymerized styrene and/or alpha-methyl styrene, and (P1c) copolymerized acrylonitrile, (P2) at least one styrene-acrylonitrile copolymer, (P3) at least one thermoplastic polymer comprising e.g. styrene polymers, polyacrylates, polycarbonates and polyesters, which are different from (P1) and (P2), (S) at least one stabilizer comprising (S1) phosphite compounds (I) and (S2) phosphinite compounds (II), and (Z) further additives. Foam comprises (P) a thermoplastic polymer comprising (P1) 30-100 pts. wt., preferably 45-75 pts. wt. at least one styrene copolymer which comprises (P1a) 1-35 wt.%, preferably 2-28 wt.% polymerized maleic anhydride units, (P1b) 64-99 wt.%, preferably 98-72 wt.% polymerized styrene and/or alpha-methyl styrene, and (P1c) 0-35 wt.%, preferably 0-28 wt.% copolymerized acrylonitrile, (P2) 0-70 pts. wt., preferably 25-55 pts. wt. at least one styrene-acrylonitrile copolymer having a styrene- and/or alpha-methylstyrene content of 65-90 wt.%, (P3) 0-15 pts. wt., preferably 0-10 pts. wt. at least one thermoplastic polymer comprising styrene polymers, polyacrylates, polycarbonates, polyesters, polyamides, polyether sulfones, polyether ketones or polyether sulfides which are different from (P1) and (P2), (S) 0.1-5 pts. wt., preferably 0.5-3 pts. wt. at least one stabilizer based on the component (P), comprising (S1) phosphite compounds of formula (P(OR) 3) (I) and (S2) phosphinite compounds of formula (II), and (Z) 0.1-10 pts. wt. further additives, based on the component (P). The component (P1c) or (P2) is present in a proportion of at least 1 pts. wt. or at least 1 wt.%. The total weight of the components (P1), (P2) and (P3) of the thermoplastic polymer is 100 pts. wt.. R : phenyl (substituted by 1-3 1-6C alkyl); and R1 : phenyl (substituted by 1-3 1-6C alkyl or 1-10C alkyl). Independent claims are also included for: (1) producing the foam, comprising (a) producing a polymer melt from the component (P), component (S) and optionally the component (Z), (b) introducing at least one propellant, and (c) extruding or granulating the foamable melt to obtain desired foam product; (2) producing an extrusion foam, comprising (i) producing the polymer melt from the component (P), component (S) and optionally the component (Z), (ii) introducing a propellant component which comprises (T1) 1-5 pts. wt. carbon dioxide as a blowing agent, based on the component (P), (T2) 1-5 pts. wt. acetone as a co-blowing agent, based on the component (P), and (T3) 0-1 pts. wt. at least one co-propellant, preferably 1-4C alkanes, into the polymer melt for forming a foamable melt, and (c) extruding the foamable melt in a region of lower pressure under foaming to obtain the extrusion foam; (3) producing expandable granules, comprising (A) providing the component (P), (B) heating the component (P) for forming the polymer melt, (C) introducing 1-8 wt.% a propellant component into the polymer melt for forming a foamable melt, (D) homogenizing the mixture, (E) adding the component (S) and optionally the component (Z) to the component (P) in at least one of the steps (A), (B), (C) and/or (D), (F) extruding the propellant-containing polymer melt through a die plate, and (G) granulating the propellant-containing melt in a liquid-filled chamber under a pressure of 1.5-20 bars to form granulates; (4) a foam molded part produced from the expandable granules; and (5) a composite molded part comprising a first layer which is the foam molded part, and at least one further layer connected with the first layer, which is the extrusion foam. [Image].