| 摘要 |
1464066 Blowing agent mixtures BAYER AG 26 Aug 1975 [29 Aug 1974] 35128/75 Heading C3C A blowing agent mixture comprises 1,4- butanediol-bis-(carbonic acid ester-benzoic acid anhydride) of formula and finely divided silicon dioxide which preferably has a BET specific surface area of 50-400 m.<SP>2</SP>/g. The blowing agent mixture may be mixed with a granulated thermoplastic resin, e.g. a polycarbonate, polyamide, polyester or mixture of a polyphenylene ether and a polystyrene, which may be substituted, which contains a dispersed gel of a butadiene/styrene copolymer with optionally polybutadiene, and the resulting mixture is foamed by heating. |
