A process for preparing open-cell polyurethane and/or polyisocyanurate rigid foams

• Main Authors: KLAEN, WALTER, SANDERS, JOSEF, HEINEMANN, TORSTEN, KLESCZEWSKI, BERT
• Format: Patent
• Language: English
• Published: 16.05.2001
• Edition: 7
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

A process for preparing largely open-cell polyurethane and/or polyisocyanurate rigid foams by reacting (A) a polyol component containing on average at least two groups capable of reacting with isocyanates and containing (1) polyethers and/or polyesters containing at least two groups capable of reacting with isocyanates, (2) water, (3) optionally catalysts and (4) optionally further auxiliary agents and additives with (B) a polyisocyanates with an NCO-content of 20 to 48 wt.%, characterised in that (C) an inorganic solid, finely distributed in a liquid phase, and with a specific surface area in the range 10 m2/g to 500 m2/g is added to the reaction mixture in an amount in the range 0.01 to 9 wt.%, preferably 0.01 to 5 wt.%, sum of components A and B. The use of rigid foams prepared in this way as intermediate layers for composities, as foaming materials for the cavities for refrigerating appliances and as fillers for producing vacuum insulation panels is also described.