Flame retardant aromatic polycarbonate with good mechanical properties and melt stability
AssigneeMobay Chemical Corporation
InventorGerard E. Reinert
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Abstract
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.
Claims16
A thermoplastic aromatic polycarbonate composition consisting essentially of:
- (a) a thermoplastic aromatic polycarbonate having a melt flow of between 1 and 24 grams per ten minutes,
- (b) between about 0.01 and 1 wt. %, based on the weight of the total composition, of an alkali metal salt of an inorganic acid,
- (c) between about 0.01 and 1 wt. %, based on the weight of the total composition, of a fibril forming polytetrafluoroethylene, and
- (d) between 0.05 and 1.0 wt. %, based on the weight of the total comparison, of aromatically bound chlorine or bromine contained in a compound other than an organic alkali metal or alkaline earth metal salt.
An unreinforced molding composition having a UL item 94 rating of 94V-O at 1.6 mm, thermal stability at 300.degree. C. and good mechanical properties consisting essentially of:
- (a) an aromatic thermoplastic polycarbonate which has a melt flow of between about 1 and 24 grams per 10 minutes and which is derived from 4,4'-dihydroxy diaryl methanes,
- (b) between about 0.1 and 0.5 wt. % of a Li, K, or Na salt of an inorganic acid,
- (b) between about 0.05 and 0.2 wt. % of fibril forming polytetrafluoroethylene, and
- (d) between about 0.1 and 0.5 wt. % of aromatically bound chlorine or bromine contained in a compound other than an organic alkali metal or alkaline earth metal salt
- wherein the weight percents are based on the total composition.
A thermoplastic aromatic polycarbonate composition consisting essentially of:
- (a) between about 0.01 and 1 wt. %, based on the weight of the total composition, of an inorganic alkali metal complex fluoro anion salt,
- (b) between about 0.01 and 1 wt. %, based on the weight of the total composition, of a fibril forming polytetrafluoroethylene, and
- (c) between 0.05 and 1.0 wt. %, based on the weight of the total composition, of aromatically bound chlorine or bromine.
An unreinforced molding composition having a UL item 94 rating of 94V-O at 1.6 mm, thermal stability at 300.degree. C. and good mechanical properties consisting essentially of:
- (a) an aromatic thermoplastic polycarbonate which has a melt flow of between about 1 and 24 grams per 10 minutes and which is derived from 4,4'-dihydroxy diaryl methanes,
- (b) between about 0.1 and 0.5 weight % of an inorganic alkali metal complex fluoro anion salt,
- (c) between about 0.05 and 0.2 weight % of fibril forming polytetrafluoroethylene, and
- (d) between about 0.1 and 0.5 weight % of aromatically bound chlorine or bromine,
- wherein the weight percents are based on the total composition.
Dependencies are inferred from the claim text.