| 摘要 |
1284676 Cellular polyurethanes ATLAS CHEMICAL INDUSTRIES Inc 20 May 1970 [21 May 1969] 24453/70 Headings C3C and C3R Rigid polyurethane foams are prepared by reacting a polyisocyanate with a polyether containing at least 3 OH groups and having a hydroxyl number of 350 to 650 in the presence of a foaming agent and 0À05 to 0À5% by weight based on the total weight of polyisocyanate and polyether, of a finely divided, solid material insoluble in, and non-reactive with, the polyurethane foam forming components, the solid material having a particle size of 0À01 to 250 microns. Conventional catalysts and surfactants may be incorporated in the reaction mixture. The solid material is suitably mixed first with the polyether and this mixture is then reacted with the polyisocyanate. Exemplary of the solid materials are asbestos, activated carbon, diatomaceous earth, barytes, litharge, aluminium flakes and powder, flake graphite, bentonite, montmorillonite, atapulga clay, calcium silicate, magnesium carbonate, glass flakes and fibres, mica, hydrated calcium silicate, talcum, silica, mineral black, titanium dioxide and lead oxide. In a typical example toluene diisocyanate is reacted with a mixture of polyoxyethylene (10) sorbitol, an organo-silicon surfactant, a mixture of triethylene diamine and dimethylethanolamine as catalyst, water, asbestos of average particle size 22 microns and trichlorofluormethane to form a fine-celled polyurethane foam.
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