Abstract:

In order to solve poor color fastness and serious color transfer of the traditional color polyurethane leather because of weak interaction(intermolecular force) between polyurethane and color base. A kind of reactive color diol was synthesized as follows:p-aminoacetanilide with a yield of 85% was prepared by acylation of p-phenylenediamine with acetic anhydride in tetrahydrofuran at 0~5 ℃ for 15 h, during which the molar ratio of p-phenylenediamine to acetic anhydride was 1.00∶0.95. Then its diazonium salt was coupled with an excess molar fraction of 5% N-phenyl-diethanolamine to obtain 4-acetylamino-4'-N,N-dihydroxyethylamino azobenzene with yield of 82%. The reactive color diol was mixed with polyester or polyether diol in different proportions, followed by prepolymering, chain extension with diisocyanate to form polyurethane resin color paste whose crack-growth rate, relative breaking strength, and color transfer are 443%, 125.5 g and 21.4 μg, respectively, when spreaded into a film. And those of the similar film obtained from import diol are 442.2%, 125.3 g and 29.2 μg, respectively, indicating that the synthetic color diol is superior to the imported product.

Key words: p-phenylenediamine, acetylation, diazo coupling reaction, azo-compound, red polyurethane, color transfer