Aqueous polyurethane dispersions containing modified hydrazide groups and their use in one-component thermoset compositions

US6455631B1 · kind B1 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Harald Blum · Wachtendonk, DE
• Lyubov Gindin · Pittsburgh, US
• Karen Henderson · Dorpsstraat, US
• Patricia B. Jacobs · Pittsburgh, US
• Sze-Ming Lee · Pittsburgh, US
• Brian Long · Clarington, US
• Robert A. Sylvester · Hilton, US
• Douglas A. Wicks · Mount Lebanon, US

Key dates

• Filing date: Dec 1, 2000
• Grant date: Sep 24, 2002
• Expiry date: Jan 5, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31942
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to aqueous polyurethane dispersions wherein the polyurethanes contain terminal hydrazide groups and correspond to the formula wherein the terminal, modified hydrazide groups are present in an amount of 1 to 25% by weight [calculated as C(O)—NH—NH—C(O), MW 84], based on the weight of the polyurethanes, and wherein X represents OR′ or NHR′, R represents the residue obtained by removing the isocyanate groups from an NCO prepolymer, R′ represents a group which is inert to Isocyanate groups under the conditions used to form the polyurethane of in formula I, R″ represents a divalent, linear or branched aliphatic group containing 2 to 10 carbon atoms, provided that there are at least two carbons between the oxygen atoms, wherein the aliphatic group may optionally be substituted by heteroatoms to form ether or ester groups, m is 0 or 1 and n is 2 to 4.