Process for producing rigid polyurethane foams

摘要

A process for producing a rigid polyurethane foam by reacting an organic polyisocyanate with a polyol component containing a compound with at least two hydrogen atoms which are reactive toward isocyanate groups in the presence of a blowing agent, a catalyst, and optionally auxiliaries and additives, wherein the polyol component contains, by weight: 20 to 60 parts of a polyether alcohol having a functionality of 3.5 to 5.5 and a hydroxyl number of from 400 to 550 mg KOH/g; 1 to 20 parts of a polyether alcohol based on an aliphatic amine and having a functionality of 3.5 to 4.5 and a hydroxyl number of 450 to 900 mg KOH/g; 10 to 30 parts of a polyether alcohol and/or aromatic polyester alcohol having functionalities of 1.5 to 3 and a hydroxyl number of from 150 to 450 mg KOH/g; and optionally 1 to 5 parts of water.

主权项

1. A polyol component b), consisting of:
based on 100 parts by weight of the polyol component b),
b1) from 20 to 60 parts by weight of at least one high-functionality polyether alcohol based on a hydroxyl-comprising compound and having functionality of from 3.5 to 5.5 and a hydroxyl number of from 400 to 550 mg KOH/g,b2) from 5 to 15 parts by weight of at least one polyether alcohol based on an aliphatic amine and having functionality of 4 and a hydroxyl number of from 470 to 800 mg KOH/g,b3) from 10 to 30 parts by weight of at least one polyether alcohol having functionality of from 2 to 3 and a hydroxyl number of from 220 to 430 mg KOH/g, andb4) optionally, from 1 to 5 parts by weight of water.