Patent EP-2565223-A1 (EP)
Inventor: BELLIN INGO DR
IPC: C08L25/16
Filed: 2011-08-31
Abstract: Expandable granules with a nitrogen content of (= 8 wt.% based on expandable granules), whose particles respectively contain at least 10 hollow spaces/mm 3>with the size of 1-200 mu m, comprises a polymer component having a glass transition temperature of more than 105[deg] C, formed from (a) a styrene polymer component, which is formed from (a1) at least one styrene polymers, each containing copolymerized styrene, alpha-methyl styrene or copolymerized mixture of alpha-methyl styrene and styrene and (a2) at least one styrene copolymer different from (a1), and (b) at least one thermoplastic polymer. Expandable granules with a nitrogen content of (= 8 wt.% based on expandable granules), whose particles respectively contain at least 10 hollow spaces/mm 3>with the size of 1-200 mu m, comprises a polymer component having a glass transition temperature of more than 105[deg] C, formed from (a) a styrene polymer component (75-100 wt.%, based on polymer component), which is formed from (a1) at least one styrene polymer (10-100 wt.%, based on polymer component), each containing copolymerized styrene, alpha-methyl styrene or copolymerized mixture of alpha-methyl styrene and styrene (60-100 wt.%, based on styrene polymer) and at least one copolymerized monomer (0-40 wt.%, based on styrene polymer) including acrylate, maleic anhydride, maleimide, 1-10C alkyl (meth) acrylate or (meth)acrylic acid and (a2) at least one styrene copolymer different from (a1) (0-90 wt.%, based on polymer component) including copolymerized styrene, alpha-methyl styrene or the copolymerized mixture of styrene and alpha-methyl styrene (60-82 wt.%, based on styrene copolymer different from (a1)) and copolymerized acrylonitrile (18-40 wt.%, based on styrene copolymer different from (a1)), and (b) at least one thermoplastic polymer (0-25 wt.% based on polymer component) including aromatic polyether, polyolefin, polyacrylate, polycarbonate, polyester, polyamide, polyethersulfone, polyether ketone or polyether sulfide, where in addition to copolymerized styrene, at least one copolymerized monomer, styrene copolymer different from (a1) and thermoplastic polymer are present in a proportion of (at least 5 wt.%, based on styrene polymer, styrene polymer component and polymer component, respectively). Independent claims are also included for: (1) producing granules, comprising (i) providing the above mentioned polymer component, (ii) heating the polymer component to form a polymer melt, (iii) introducing a physical blowing agent component (1-10 wt.%, based on polymer component) into the polymer melt to form a foamable melt, (iv) homogenizing the mixture, (v) optionally, adding additives to the polymer component in at least one of the steps (i), (ii), (iii) and/or (iv), (vi) extruding the polymer melt comprising blowing agent through a nozzle plate, and (vii) granulating the melt comprising blowing agent in a liquid-filled chamber under a pressure of 1.5-15 bar to form the granulate, whose particles contain at least 10 cavities/mm 3>in the size range of 1-200 mu m; (2) a foam molded part with a density of 40-200 g/l, obtainable by the expandable granule; and (3) a composite molded part, comprising a first layer and at least one further connected to the first layer, where the first layer is formed as the foam molded part with a cell number of 1-30 cells/mm, the density of 40-200 g/l, and the nitrogen content of (= 8 wt.%, based on the particle foam molded part).