Abstract: The present invention relates to a method for producing a polyester polyol having a concentration of ether groups in the range from 9.0 mol/kg of polyester polyol to 22 mol/kg polyester polyol, characterized in that (i) in a first step (A) isophthalic acid, optionally in the form of a C1-C4 alkyl ester, and/or terephthalic acid, optionally in the form of a C1-C4 alkyl ester, is reacted with (B) oligoethylene glycol of the formula H—(OCH2CH2)n—OH having a numerical average number of oxyethylene groups n in the range from 3.0 to 9.0, in the presence of at least one catalyst selected from the group made up of tin(II) salts, bismuth(II) salts, and titanium tetraalkoxylates, at a temperature in the range from 160° C. to 240° C.

Abstract: A process for the preparation of polyricinoleic acid esters comprising the step of reaction of ricinoleic acid with an alcohol component which comprises mono- and/or polyfunctional alcohols having a molecular weight of ?32 g/mol to ?40 g/mol, wherein the reaction is carried out at least partly in the presence of a catalyst. The amount of catalyst, based on the total weight of the ricinoleic acid and the alcohol component, is in a range of from ?10 ppm to ?100 ppm. The reaction is ended when the acid number of the reaction product obtained is ?5 mg of KOH/g to ?100 mg of KOH/g. The invention furthermore relates to a polyurethane polymer, in particular a flexible polyurethane foam, which is obtainable using these polyricinoleic acid esters.

Abstract: The present invention relates to a method for producing a polyester polyol having a concentration of ether groups in the range from 9.0 mol/kg of polyester polyol to 22 mol/kg polyester polyol, characterized in that (i) in a first step (A) isophthalic acid, optionally in the form of a C1-C4 alkyl ester, and/or terephthalic acid, optionally in the form of a C1-C4 alkyl ester, is reacted with (B) oligoethylene glycol of the formula H—(OCH2CH2)n—OH having a numerical average number of oxyethylene groups n in the range from 3.0 to 9.0, in the presence of at least one catalyst selected from the group made up of tin(II) salts, bismuth(II) salts, and titanium tetraalkoxylates, at a temperature in the range from 160° C. to 240° C.

Abstract: Polyester polyols are produced by reacting terephthalic acid with a glycol corresponding to the formula H—(OCH2CH2)n—OH and an aliphatic dicarboxylic acid.

Abstract: Polyester polyols are produced from at least one carboxylic acid hydride and diethylene glycol by a process in which the formation of 1,4-dioxane is suppressed. These polyester polyols are useful for producing polyurethane (PUR) and polyisocyanurate (PIR) foams and metal composite elements containing these PUR or PIR foams.