摘要 |
1529407 Flame-retardant polycarbonate compositions GENERAL ELECTRIC CO 28 Oct 1976 [29 Oct 1975] 44934/76 Addition to 1496680 Heading C3R A non-opaque flame-retardant composition comprises an aromatic polycarbonate and from 0À001 to 2À0% by weight, based on the polycarbonate, of an alkali metal or alkaline earth metal salt of a heterocyclic sulphonic acid wherein the hetero atom is nitrogen, oxygen or sulphur, the polycarbonate and the salt both having a refractive index of from 1À54 to 1À65. Many salts are specified, e.g. potassium dibenzofuran-3-sulphonate and potassium 2,5-dichlorothiophene-3-sulphonate, |