Process for preparing open-cell, cold-mouldable, rigid polyurethane-foams and their use for procuding roof linings of cars

摘要

Open-cell, low-temperature-mouldable, rigid polyurethane foams are produced by reacting a mixture of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanantes comprising … …  1.) 70-90 % by weight of diphenylmethane diisocyanates, of which …  2.) 12-30 % by weight, preferably 15-25 % by weight, are 2,4'-diphenylmethane diisocyanate, and …  3.) 10-30 % by weight of polyphenylpolymethylene polyisocyanates, … with a polyol mixture comprising … …  1.) 50-70 % by weight of difunctional and/or trifunctional, hydroxyl-containing polyethers having an OH number of 28-600, …  2.) 20-35 % by weight of a difunctional, hydroxyl-containing phthalic acid polyester having an OH number of 150-440, …  3.) 2-10 % by weight of glycerol, …  4.) 4-7 % by weight of water, …  5.) 0.1-2 % by weight of a silicone foam stabiliser and …  6.) 0.3-1 % by weight of a tert.-amine catalyst which is capable of incorporation, … and are used for the production of roof linings for cars.