Molecular weight control of polyurethane elastomers
AssigneesMobay Chemical Corporation, Bayer Aktiengesellschaft
InventorsWalter Meckel, J. W. Britain
Life of this patent
Estimating the term…
Abstract
Polyurethane elastomers are prepared by reacting organic polyisocyanates with organic polyhydroxyl compounds and a mono-functional secondary hydroxyl group containing chain terminator. The chain terminator can be added to the polyhydroxyl compound prior to the reaction with the polyisocyanate.
Claims8
A process for producing elastomeric polyurethanes comprising reacting organic polyisocyanates with organic polyhydroxyl compounds having a molecular weight of from about 800 to about 5,000, containing at least two OH groups reactive with NCO groups such that the NCO/OH ratio is from about 0.9:1 to about 1.1:1 and incorporating into the reaction mixture a chain terminator having the general formula:
- ##STR2## wherein R and R' are the same or different and represent alkyl groups containing at least 3 carbon atoms which may be branched in the .alpha.- or .beta.-positions, which may be substituted with halogen atoms, and which may contain hetero atoms in the form of esters or ethers, and wherein the chain terminator is present in an amount from about 0.1 percent to about 3 percent based on the molecular equivalent of all available OH groups.
Dependencies are inferred from the claim text.