| 摘要 |
1458080 Process for making simulated leather KAO SOAP CO Ltd and NIPPON CLOTH INDUSTRY CO Ltd 4 July 1974 [4 July 1973] 29679/74 Heading B2E Air permeable simulated leather is prepared by incorporating a catalyst and a foam stabiliser into an isocyanate terminated polyurethane prepolymer formed from a polyester diol derived from an aliphatic dicarboxylic acid and a polyisocyanate so that the (NCO)/ (OH) ratio is 2.0 to 4.0 to form a solvent free paint of viscosity 70-1000 poise, coating 50- 400 gm. paint on a release paper which is then applied to a substrate. The assembly is contacted with moisture for 30 seconds to 5 minutes at a dry bulb temperature of 40 to 95‹C and relative humidity at least 60% causing polymerisation and foaming and while reaction is still taking place passing the assembly between an upper roller and a lower roller spaced so that the foaming ratio is 2 to 4 in the polyurethane foam layer, allowing reaction to proceed further and removing the release paper. Suitable glycols include ethylene glycol, 1, 4-butanediol, 1, 5-pentadiol and 1, 6-hexanediol and there may be condensed with at least one member selected from adipic acid, pirrelic acid and suberic acid. An embossed release paper may be employed. The simulated leather miay be surface coated by applying a layer of a polyurethane resin, an amino acid resin or an acrylic resin to the release paper before treating with the foamable polyurethane layer. |
