摘要 |
Low melting point compositions, comprising a mixture of diisocyanate isomers having the diphenylethane structure, and containing by weight about: 35 to 55% of 2,4' isomer, 15 to 40% of 4,4' isomer, 10 to 25% of 2,2' isomer, 3 to 10% of 3,4' isomer, and 3 to 8% of 2,3' isomer; to the method of making such compositions by the nitration of aromatic diphenylethane rings, followed by a hydrogenation and phosgenation; and polyurethanes formed utilizing such compositions. |