| 摘要 |
1,170,371. Modified tolylene diisocyanate compositions. SUMITOMO CHEMICAL CO. Ltd. 17 Jan., 1968 [20 Jan., 1967], No. 2598/68. Heading C2C. [Also in Division C3] A method for the preparation of a modified toluylenediisocyanate composition comprises heating a toluylenediisocyanate at a temperature between 150-270‹ C. in the presence of one or more organo-tin compounds of the general formula RR<SP>1</SP>Sn(OOC.CH = CH.COO.C m H 2m OH) 2 wherein R and R<SP>1</SP> are alkyl groups and m represents an integer of from 2 to 4. The treatment of 2,4-toluylenediisocyanate in the presence of di - n - octyltin - di(propylene glycol maleate), di-n-butyltin-di(propylene glycol maleate) or di-n-butyl-tin-di(ethylene glycol maleate) is exemplified. A rigid polyurethane foam may be formed by the " one-shot " method using a toluylenediisocyanate treated according to the invention and a polyol. |
