METHOD OF OBTAINING ALIPHATIC POLYESTER, POSSESSING INCREASED MOLECULAR WEIGHT Russian patent published in 2014 - IPC C08G18/42 C08G63/12 C08G63/88 C08G63/91 C08G63/685 

FIELD: chemistry.

SUBSTANCE: method of obtaining an aliphatic polyester, possessing an increased molecular weight, includes stages (i) of a quantitative introduction of diisocyanate in a polyester-based prepolymer, which has a number-average molecular weight of 5000 or higher and contains terminal hydroxyl groups, and in which at least one acidic component is represented by a succinic acid compound in a melted condition at a temperature not lower than its fusion temperature, where the quantity of disiocyanate is equivalent to the value between one tenth and double quantity of the hydroxyl groups in the prepolymer based on the aliphatic polyester, (ii) a quantitative and continuous introduction of the prepolymer based on the aliphatic polyester, containing diisocyanate, obtained at stage (i), in a mixing vessel, its unloading from the mixing vessel at mixing and its supply into a reservoir for a reaction of combination and (iii) realisation of the interaction of the prepolymer based on the aliphatic polyester with diisocyanate in the reservoir for the reaction of combination.

EFFECT: method is continuous and makes it possible to obtain the aliphatic polyester, possessing an increased molecular weight with the lower probability of gelation and lower formation of fish-eye defects.

10 cl, 3 dwg, 1 tbl, 3 ex