Process for the preparation of polyols
View Patent ↗The present invention provides polyols which can be obtained by a simple process. These polyols, unless explicitly specified, are to be understood to encompass both polyether polyols and polyether ester polyols. The invention further provides the simple process for the production of the polyols, and also, the production of polyurethanes comprising reacting a polyol according to the invention with a polyisocyanate.
1. A process for the preparation of polyols comprising
(1) base-catalysed addition of
(a) one or more alkylene oxides, wherein the proportion of ethylene oxide in the alkylene oxides is at least 10 weight %, based on 100 weight % of the alkylene oxides,
to
(b) one or more polyfunctional starter compounds having Zerewitinoff-active hydrogen atoms,
in the presence of
(c) one or more catalysts selected from the group consisting of alkali metal hydroxides, alkali metal hydrides, alkaline earth metal hydrides, alkali metal carboxylates, alkaline earth metal carboxylates and alkaline earth hydroxides, in which the concentrations of said catalysts, based on the amount of end product, is from 0.004 to 0.5 weight %,
(2) neutralizing the alkaline polymerisation-active centers of the crude alkylene oxide addition product by adding sulfuric acid in such a manner that, of from 66 mol % to 100 mol % of the acid used, only the first dissociation stage of sulfuric acid is effective for neutralization of the amount of catalyst contained in the crude polymer,
wherein the resultant polyols are not filtered.
2. The process of claim 1 , in which from 10 to 80 weight % of triglycerides, based on the amount of end product, are added before or during the addition of the alkylene oxides.
3. The process of claim 1 , wherein the concentrations of said catalysts, based on the amount of end product is from 0.01 to 0.1 weight %.
4. The process of claim 1 , wherein the proportion of ethylene oxide in the alkylene oxides is at least 20 weight %, based on 100 weight % of the alkylene oxides.
5. The process of claim 1 , wherein the resultant polyol is clear and has a base content of less than 100 ppm.
6. The process of claim 5 , wherein the base content is less than 50 ppm.