Fire-resistant, transparent polycarbonate(s) - contain polycarbonate(s) with iso:octyl:phenyl and/or iso:nonyl:phenyl end gps. based on specific di:phenol(s) and alkali sulphonate fire retardant(s)

摘要

Branched aromatic polycarbonates with Mw 12,000-29,000 (by GPC) are claimed (I), based on diphenols (II), with iso-octylphenyl and/or iso-nonylphenyl end gps. and contg. alkali sulphonate fire retardant (III); (I) contain only diphenols of formula (II): X = 1-5C alkylidene, -S- or a single bond; R = Me, Cl or Br; n = 0, 1 or 2. Pref., (I) is 4,4'-dihydroxybiphenyl, 4,4'-dihydroxy-diphenyl sulphide or Bisphenol A; the end gps. are derived from 3.5-6 mol. % 8-9C branched alkylphenols as chain cleavage agents, and pref. chain branching agent is 3,3-bis-(4-hydroxyphenyl)-2-keto-2,3-dihydro-indole or the corresp. 4-hydroxy-3-methylphenyl cpd.; pref. (III) is K perfluoroalkane-sulphonate (with alkane = methane, ethane, propane or butane) or K diphenylsulphone-sulphonate, in amts. of 0.03-0.3 wt. %. USE/ADVANTAGE - Provides (I) with an ideal combination of good fire resistance, flow properties and transparency, and high impact strength, without incorporating special bis-hydroxyaryl-cycloalkanes in the diphenol component.