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US 4,732,949 AGranted
Polydiorganosiloxane/polycarbonate block copolymers
AssigneeBayer Aktiengesellschaft
InventorsWinfried Paul, Werner Nouvertne, Hartmut Lower, Mark W. Witman, Ulrich Grigo
Life of this patent
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Abstract
The present invention relates to the preparation of thermoplastic poly-(diorganosiloxane)/polycarbonate block copolymers containing monoalkylphenyl or dialkylphenyl end groups by the phase boundary process, and to the block copolymers which can be obtained by the process.
Claims8
A process for the production of a thermoplastic poly-(diorganosiloxane)/polycarbonate block copolymer comprising reacting
- (a) .alpha.,.omega.-bis-hydroxyaryloxy polydiorganosiloxane having a degree of polymerization of between 5 and 100,
- (b) at least one other diphenol,
- (c) a chain stopper and, if desired,
- (d) a chain branching agent,
- with phosgene in the two-phase boundary process characterized in that said chain stopper is a member selected from the group consisting of a monoalkylphenol, a halogenocarbonic acid ester of a monoalkyl phenol, a dialkylphenol and a halogenocrbonic acid ester of a dialkyl phenol wherein the alkyl substituents contain 8 to 20 carbon atoms and in that chain stopper is employed in a sufficient amount such that a quantitative reaction of the phenolic component is obtained, said copolymer being characterized in that its weight average molecular weight, determined by ultracentrifugation or by light scattering, is about 10,000 to 30,000 and in that it contains 0.5 to 10% by weight of poly-(diorganosiloxane) structural units.
2 more elements
In the process for the preparation of a thermoplastic poly-(diorganosiloxane)/polycarbonate block copolymer in the two phase boundary process by reacting
- (a) .alpha.,.omega.-bis-hydroxyaryloxy polydiorganosiloxane having a degree of polymerization of between 5 and 100,
- (b) at least one other diphenol,
- (c) a chain stopper and, if desired,
- (d) a chain branching agent
- with phosgen, said copolymer being characterized in that its weight average molecular weight determined by ultra-centrifugation or by light scattering is about 10,000 to 30,000 and in that it contains 0.5 to 10% by weight of poly-(diorganosiloxane) structural units, the improvement comprising using as a said chain stopper, a member selected from the group consisting of a monoalkylphenol, a halogenocarbonic acid ester of a monoalkylphenol, a dialkylphenol and a halogenocrbonic acid ester of a dialkylphenol wherein the alkyl substituents contain 8 to 20 carbon atoms, in a sufficient amount such that a quantitative reaction of the phenolic component is obtained.
2 more elements
Dependencies are inferred from the claim text.