Process for the preparation of optionally cellular polyurethane polyurea molded parts with improved demolding characteristics

US4636531A · kind A · utility

Assignee

• BASF SE

Inventors

• Hans U. Schmidt · Griesheim, DE
• Frank Werner · Jackson, US

Key dates

• Filing date: Feb 13, 1985
• Grant date: Jan 13, 1987
• Expiry date: Feb 13, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/249989
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the preparation of cellular, microcellular and noncellular polyurethane polyurea molded parts through the reaction of organic polyisocyanates, polyols having at least 2 reactive hydrogen atoms, and a chain extender containing at least 70 percent by weight of a mixture of aromatic diamines comprising from 80 to 50 weight percent of at least one primary aromatic diamine whose amino groups are sterically hindered relative to reaction with polyisocyanates, and 20 to 50 weight percent of at least one unsubstituted or substituted reactive primary aromatic diamine whose amino groups do not exhibit reduced reactivity to polyisocyanates. These reactive mixtures produce polyurethane polyurea polymers with excellent demoldability without the use of external mold release agents.