| 摘要 |
<p>A solution of a polyurethane in a polyol is made from (a) the reaction product of a polyisocyanate and a diprimary diol, and (b) a polyether in which the reaction product constituted from 3 to 60 wt. % of the solution Suitable diprimary diols have a molecular weight of from 90 to 800 and a structure at both hydroxyl groups corresponding to the general formula: in which R1 represents chlorine, an alkyl, cycloalkyl, aralkyl or aryl radical having from 1 to 10 carbon atoms, which carbon atoms may be substituted or interrupted by chlorine, ester groups, ether groups, amide groups, urethane groups or nitrile groups, and R2 represents hydrogen or a radical within the definition of R1. Polyethers which may be employed have at least two hydroxyl groups (at least 80% of which are secondary hydroxyl groups) and an average molecular weight of from 500 to 12,000. The disclosed solutions are particularly useful in the production of flexible polyurethane plastics which are suitable for flamecoating and high frequency bonding.</p> |
