A method for the production of fluorochlorohydrocarbon - free polyurethane - flexible foams with the use of a polyisocyanate mixture containing urethane groups on diphenylmethane - diisocyanate base as well as such modified polyisocyanate mixtures

摘要

items of the invention are a process for the production of cfc free polyurethane soft foams (form) through implementation of $(a) liquid, urethangruppen containing bound polyisocyanatmischungen containing nco groups of 20 to 30% by weight.-%the part produced by implementing a mixture of diphenylmethan - diisocyanaten and polyphenyl - polymethylen - polyisocyanaten (crude mdi) with a polyether polyolmischung with a hydroxylzahl 120 to 25 from at least one polyoxypropylene glycol and at least one trifunkti onellen polyoxypropylene polyoxyethylene polyol containing ethylenoxideinheiten from 90 to 10wt.-% or by application of 4,4 '- diphenylmethan - diisocyanates (mdi) or mdi isomer mixture with said polyetherpolyolmischung to nco groups containing quasipru00e4polymeren and dilution of this quasipru00e4polymeren with crude mdi,with $a (b) hu00f6hermolekularen polyhydroxylverbindungen and, where appropriate, $a (c) low molecular weight kettenverlu00e4ngerungs and / or vernetzungsmitteln $a $a (d) in the presence of propellant, $a (e) catalysts and, where appropriate, $a (f) tools and / or additives, $a and erfindungsgemu00e4u00df type products with urethangruppen modified polyisocyanatmischungen (a).