| 摘要 |
The present invention is directed to a process for the preparation of a stable, liquid adduct comprising reacting a mixture of 1,3-butane diol and propylene glycol with diphenylmethane diisocyanate at a temperature of from about 25 DEG C. to about 120 DEG C. in an amount such that the resultant product has an isocyanate group content of from about 20 to about 30 percent by weight, and wherein the ratio of mole equivalents of 1,3-butane diol to mole equivalents of propylene glycol is from 0.05:0.95 to 0.95:0.05, with the further proviso that (i) if the 4,4'-isomer content of the diphenylmethane diisocyanate is equal to or greater than 90 percent by weight, then said ratio is from 0.45:0.55 to 0.70:0.30, and (ii) if the 4,4'-isomer content of the diphenylmethane diisocyanate is less than 90 percent by weight, but not less than 70 percent by weight, then said ratio is from 0.30:0.70 to 0.85:0.15. The invention is also directed to a product produced from such process. |
