| 摘要 |
1,230,370. Treating mould to release polyurethane foam. GENERAL TIRE & RUBBER CO. 14 Nov., 1969 [15 Nov., 1968], No. 55910/69. Heading B5A. In the production of foamed, flexible polyurethane articles with an integral skin, the mould is treated by (a) applying a smooth coating of polytetrafluoroethylene, (b) fusing the coating, (c) spreading a thin film of a mixture comprising (by weight) 89-99% organic solvent, 3À0-0À3% surfactant and 8À0- 0À7% wax over the coating, and (d) drying the film prior to injecting the foam reactants into the mould. The mould may be made of metal, plastic or rubber and is cooled to form the skin on the foam. The organic solvent preferably comprises naphtha, the surfactant is preferably an organometallic sulphosuccinate and the wax may be an ester of a monohydric alcohol, polyethylene wax, or a hydrocarbon wax with a melting point between 190‹ and 210‹ F. and zero acid number and saponification number. After removal from the mould the foamed article may be rinsed with hot water to remove wax, or painted with an isocyanate based paint. |
