| 摘要 |
<p>In a process for the production of polyurethane foam by reacting a polyester with a diisocyanate, water and an activator, before the reaction scraps of polyurethane foam are heated with the polyester and/or the diisocyanate to form a homogeneous solution. A suitable temperature for preparing the homogeneous solutions is 130 DEG to 350 DEG C. In examples: (1) polyurethane foam scraps are dissolved at 270 DEG C. in a polyester of adipic acid, diethylene glycol and trimethylol propane; (2) polyurethane foam scraps are dissolved at 180 DEG C. in toluylene diisocyanate; (3) a foamed product is prepared by injecting into a stirred solution prepared as in Example (1) toluylene diisocyanate and an activator comprising the sodium salt of sulphonated oleic acid, aminocaprolactam, the ester of N-dimethylethanolamine with succinic acid, and water; (4) in a process similar to (3), the polyester employed is prepared from different proportions of reactants; (5) a solution produced as in Example (2) is reacted with an adipic acid/diethylene glycol/trimethylolpropane polyester in the presence of an activator as specified in Example (3); (6) a solution of polyurethane foam scraps dissolved by heating in a polyester as specified in Example (5) is subjected to a foaming reaction with toluylene diisocyanate and an activator comprising adipic acid diethanolamine, water, sulphonated castor oil and paraffin oil; (7) a solution similar to that of Example (1) is diluted with further polyester and subjected to foaming by the method of Example (3) with toluylene diisocyanate in the presence of an activator comprising the ester amine of diethylamine and adipic acid, oleic acid diethylamine, water and tin tetraoctylate. In place of toluylene alone there can be used a solution containing polyurethane foam scraps; (8) a solution of polyurethane foam scraps in toluylene diisocyanate is subjected to a foaming reaction, by the method of Example (3), with an adipic acid/diethylene glycol/dimethylol propane polyester.</p> |
