| 摘要 |
The invention relates to an esterification catalyst as T (IV) dialkoxy monochelate polymer which has a molecular mass greater than 2,500, and is in the form of solution indiol, having a titan content of 15 ... 20 g/l. The process for obtaining the esterification catalyst consists in reacting the TiCl4 with a diol or an alkane ether and an excess of polyalkanolamine in benzene, at the atmospheric pressure and at the refluxing temperature of the solvent, followed by diluting the reaction mass with an amount of diol or an alkane ether identical with the one used in the synthesis, distilling the benzene and separating the resulting hydrochloride. The process of synthesizing the polyester-polyols consists in esterifying, in the melt, an acid dicarboxylic composition with dihydroxyl component, in a molar ratio of 1.5 ...3 : 1 at an atmospheric pressure and temperatures ranging from 180 to 250 C using an inert gaseous entraining agent to remove the water resulting from the two-step reaction, the first being an autocatalytic step and the second one being a catalytic step, in the presence of the esterification catalyst used in a concentration equivalent to a content of 5 ... 10 ppm Ti in the reaction mass, up to lowering the acidity index below 1...2 mg KOH/ g. |
