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US 4,377,670 AGranted
Copolymers based on aliphatic polycarbonates and lactams
AssigneeBayer Aktiengesellschaft
InventorsHeinrich Krimm, Hans-Josef Buysch, Artur Botta
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AssigneeBayer Aktiengesellschaft
InventorsHeinrich Krimm, Hans-Josef Buysch, Artur Botta
Estimating the term…
Anionic copolymers of lactams and aliphatic polycarbonates having urethane and carboxylic acid ester groups, preferably having recurring structural units of the formula: --NH--CO--O--Y--O--CO--(CR.sub.2).sub.n -- wherein R represents hydrogen or C.sub.1 -C.sub.4 -alkyl; n represents an integer of from 2 to 13; Y represents the residue of an alcohol of the following formula: HO--X--OH, wherein X represents an open-chain, cyclic or mixed open-chain-cyclic alkylene radical having from 2 to 12 carbon atoms which is optionally substituted by C.sub.1 -C.sub.4 -alkyl and optionally interrupted by from 1 to 3 oxygen atoms, or a polyethylene glycol having a molecular weight up to 10,000 or an alkoxylation product of bifunctional phenols.
A process for the production of a copolymer having weight average molecular weights between 1,000 and 150,000 determined by light scattering measurement and containing urethane and carboxylic acid ester groups, which comprises heating at a temperature from 100.degree. to 250.degree. C. an anhydrous mixture of a lactam and an aliphatic polycarbonate having a molecular weight in the range from 1,000 to 500,000 determined by light scattering measurements in the presence of an alkaline catalyst in amounts from 0.001 to 1% by weight based on the weight of the reactants which mixtures have from 20 to 80% by weight of lactam and from 80 to 20% by weight of said polycarbonate.
A process as claimed in claim 1 in which the lactam corresponds to the formula:
A copolymer product obtained from the process according to claim 10 or claim 2 or claim 3.
Dependencies are inferred from the claim text.