The invention relates to a polymer mixture which comprises an aromatic polycarbonate, a styrene­-containing copolymer and/or a styrene-containing graft polymer and a flame-retardant. It has been found that the use of a certain type of flame-retardants, namely oligomeric phosphates leads to a polymer mixture having improved properties. In particular to a polymer mixture having a good combination of flame retardancy, non-­juicing characteristics of the flame retardant, good plastifying effect and good heat resistance.

Polymer mixture comprising an aromatic polycarbonate, a styrene-containing copolymer and/or graft polymer and a phosphate based flame-retardant; articles formed therefrom

The invention relates to a polymer mixture which comprises an aromatic polycarbonate, a styrene-containing copolymer and/or a styrene-containing graft polymer and a flame-retardant. It has been found that the use of a certain type of flame-retardants, namely oligomeric phosphates leads to a polymer mixture having improved properties. In particular to a polymer mixture having a good combination of flame retardancy, non-juicing characteristics of the flame retardant, good plastifying effect and good heat resistance.

Polymer mixture having aromatic polycarbonate styrene I containing copolymer and/or graft polymer and a flame-retardant, articles formed therefrom

This invention provides a method for preparing polycarbonates, which utilizes polycondensation catalysts which are salts of certain phenanthroline compounds. We have found that this new class of catalysts provide excellent polymerization rates for the preparation of Bisphenol A polycarbonate from the melt polymerization of diphenyl carbonate and Bisphenol A. Moreover, the catalysts of the invention were found to be very selective in substantially reducing the level of branching side reaction, i.e., formation of Fries product, normally associated with the melt polycarbonate process.

Melt polycarbonate catalyst systems

The present invention relates to thermoplastic moulding compositions which are provided with a flame-repellent finish by adding phosph(on)ate esters, tetrafluoroethylene polymers and, if appropriate, halogen compounds.

Thermoplastic moulding compositions with flame-repellent properties

Disclosed is a flame retardant comprising bisphenol A bis(diphenyl phosphate) and its dimer, the former having an HPLC determined 78 to 87 area % and an 85 to less than 90 normalized area %, the normalized area % being based on the total HPLC area % of the bisphenol A bis(diphenyl phosphate) and the dimer. The flame retardant also has a low isopropenylphenyl diphenyl phosphate and a low triphenylphosphate content.

Bisphenol-A bis(diphenyl phosphate)-based flame retardant

The present invention is concerned with flame retardant polycarbonate compositions having good mechanical properties and melt stability. These properties are achieved by adding small amounts of a fibril forming polytetrafluoroethylene, and an alkali metal salt of an inorganic acid, and a small amount of aromatically bound chlorine or bromine contained in a compound other than an organic alkali metal or alkaline earth metal salt to a thermoplastic aromatic polycarbonate.

Gerard E. Reinert

Papers

Flame retardant aromatic polycarbonate with good mechanical properties and melt stability