| 摘要 |
<p>A process of utilizing scrap material of the kind produced from liquid reaction mixtures containing active-hydrogen-containing polymeric materials, an organic polyisocyanate and water comprises dissolving the scrap material in at least an equal weight of a liquid or molten active-hydrogen-containing polymeric material at an elevated temperature and forming from the resulting solution further cellular material by reaction with water and an organic polyisocyanate. The expression "active-hydrogen-containing polymeric materials" means polyesters, polyesteramides, polyalkylene ether glycols, and mixtures of two or more of these. Suitable materials are those described in Specifications 694,982, 696,449, 696,450 and 731,071 and in U.S.A. Specification 2,692,873. Suitable polyisocyanates are hexamethylene, m- or p-phenylene, 4,41 - diphenylene, 1,5 - naphthalene, 4,41 - diphenylmethane, tolylene, 4,41-phenylether, 3,31 - dimethyl - 4,41 - diphenyl and 3,31 - dimethoxy - 4,41 - diphenyl diisocyanates; 4,41,411 - triphenyl - methane and toluene 2,4,6 - triisocyanates, 4,41 - dimethyldiphenylmethane 2,21,5,51 - tetraisocyanates, and mixtures of polyisocyanates such as those described in U.S.A. Specification 2,683,730. Solution of the scrap material is effected by heating the mixture at temperatures up to 250 DEG C., if desired in vacuo. In examples: (3) and (4) scrap foam material is dissolved by heating to 250 DEG C. under vacuum in a mixture of diethylene glycol/adipic acid and ethylene glycol/propylene glycol/adipic acid hydroxypolyesters. The solution was mixed with polyethylene glycol, a polyoxyethylated vegetable oil (surface-active agent), N-methyl-morpholine, water and a mixture of 2,4- and 2,6-tolylene diisocyanates and poured into a mould to give a foamed product. In a similar example, a diethylene glycol/adipic acid is used alone instead of the mixture of polyesters. The scrap foam material is that obtained by reacting a diethylene glycol/adipic acid hydroxypolyester with a polyethylene glycol, a polyoxyethylated vegetable oil, N-methyl-morpholine, water and mixed 2,4- and 2,6-tolylene diisocyanates.</p> |
