| 摘要 |
<p>1490635 Polyurethane coated substrates BAYER AG 31 Jan 1975 [1 Feb 1974] 4310/75 Heading B2E [Also in Division C3] Films or coatings are obtained by coating a substrate which is resistant to the temperatures used in the process with a solventfree, liquid or molten coating substance comprising a combination of a phenol and/or lactam blocked polyisocyanate with a compound which contains hydrogen atoms which are reactive with isocyanate groups, the combination having a melting point or range below 100‹C and a viscosity at the temperature at which the coating is carried out of not more than 40,000 cP and subsequently heating the coated substrate to a temperature at which final cross-linking is accompanied by removal of the blocking agent. The compound which contains active hydrogen atoms is most preferably a hydroxyl group-containing compound e.g. a low molecular weight polyol; a polyester polyol or a polyether polyol. Final cross-linking usually takes place at a temperature of 100 to 700‹C in stoving ovens. The substrate may be a metal, ceramic, glass fibres or fabrics. In Examples the substrates coated are metal wires and sheets and a glass silk fabric.</p> |
