| 摘要 |
1,250,250. Stabilizing polyisocyanates. KAISER ALUMINUM & CHEMICAL CORP. 25 June, 1969 [17 July, 1968], No. 32143/69. Heading C2C. The invention relates to a process for preventing solids formation in liquid aromatic polyisocyanates at temperatures below 25‹ C. which comprises admixing with the polyisocyanate a stabilizing amount of an organosilicone having the general formula in which R, R 1 and R 2 each represent methyl, ethyl, propyl, or phenyl groups; R 3 and R 4 each represent a hydrogen atom or a methyl, ethyl, propyl or butyl group; the chain has an average molecular weight of about 140 to about 5,000; the chain has an average molecular weight of about 60 to about 3000; the integers x and y are at least 1; and the integers a and b are each 0 or a whole number, one of a and b being at least one. Examples are given in which the polyisocyanate is polymethylene-polyphenylene-polyisocyan ate. |
