Composite elements having improved resistance against stress cracking corrosion, most preferably for low temperature housing compartments

US4996103A · kind A · utility

Inventors

• Rolf Henn · Ketsch, DE
• Reinhard Leppkes · Frankenthal (Pfalz), DE

Key dates

• Filing date: Mar 30, 1990
• Grant date: Feb 26, 1991
• Expiry date: Mar 30, 2010

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/249992
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The invention deals with composite elements having improved resistance against stress cracking corrosion especially for low temperature housing compartments, comprising: PA1 (a) at least one top layer of polystyrene, preferably toughened polystyrene, having certain mechanical properties; and PA1 (B) a layer of polyurethane foam, preferably polyurethane rigid foam; said polyurethane rigid foam prepared while using difluorochloromethane as a blowing agent or a blowing agent mixture which essentially comprises water, difluorochloromethane, and optionally trichlorofluoromethane.