Abstract: The present invention relates to a process for preparing a polyisocyanate, namely an isocyanate group-terminated polyol polyanthranilic acid ester. The process comprises the step of reacting an anthranilic acid derivative selected from anthranilic acid halide (in particular anthranilic acid chloride), isatoic anhydride or a mixture thereof with a first polyol of a number-average molar mass of at least 200 g/mol and a functionality in the range of 2 to 8, and obtaining, as a result, a polyamine (namely a polyol polyanthranilic acid ester with amine terminal groups) and reacting the polyamine with phosgene and obtaining, as a result, a polyisocyanate (namely an isocyanate group-terminated polyol polyanthranilic acid ester). The invention further relates to the polyisocyanates obtained in this way, their use in polyaddition reactions, and polyaddition products obtainable by these reactions.

Abstract: The present invention relates to an insulation body based a hard, fine-cell and open-cell polyurethane/polyisocyanurate foam with a barrier film, and a method for producing same.

Abstract: The invention provides a process for preparing polyesters by reacting an H-functional starter substance with a lactone in the presence of a Brønsted-acidic catalyst which comprises initially charging the H-functional starter substance and the Brønsted-acidic catalyst to form a mixture i) and subsequently adding the lactone to the mixture i), wherein the process is carried out without adding an aromatic solvent and wherein the H-functional starter substance is an OH-functional starter substance and/or a COOH-functional starter substance and wherein the lactone is a 4-membered ring lactone. The invention further provides polyesters obtainable by the method of the invention.

Abstract: The invention relates to a method for producing a polyoxyalkylene polyester polyol by reacting a polyoxyalkylene polyol with a lactone in the presence of a Brønsted acid catalyst, wherein the catalyst has a pKa value of 1 or less; the number-average molar mass of the polyoxyalkylene polyol is ?1000 g/mol, preferably ?1500 g/mol, particularly preferably ?2000 g/mol; and in the lactone a CH2 group is bonded to the ring oxygen. The invention further relates to polyoxyalkylene polyester polyols obtainable using the method according to the invention, and to a method for producing polyurethanes by reacting the polyoxyalkylene polyester polyols according to the invention with polyisocyanates.

Abstract: The present invention relates to open- and fine-celled rigid polyurethane foams which contain not only urethane groups (PUR) but also isocyanurate groups (PIR) and carbodiimide groups (CD) and to the use thereof in vacuum insulation panels.