Abstract: The invention relates to a method for producing polyisocyanates having a low monomer content, said method comprising the following steps: (i) modifying at least one monomeric diisocyanate to obtain a mixture containing at least one polyisocyanate and unconverted monomeric diisocyanate, (ii) separating the mixture obtained in step (i) into at least one gaseous stream containing monomeric diisocyanate and a liquid stream depleted of monomeric diisocyanate, (iii) partially condensing the gaseous stream from (ii) in at least one condenser, so that a liquid condensate and an uncondensed vapour stream are obtained, (iv) post-condensing the uncondensed vapour stream obtained in step (iii) in at least one post-condenser, so that a post-condensate and an uncondensed waste gas are obtained, and (v) delivering the uncondensed waste gas from step (iv) to the suction side of a vacuum pump, characterised in that the at least one post-condenser in step (iv) is operated at a post-condenser temperature, and the at least one c

Abstract: A process for producing rigid PUR/PIR foams comprising A1 an isocyanate-reactive component, A2 a flame retardant, A3 a blowing agent, A4 a catalyst, A5 optionally auxiliaries and additives, and B an organic polyisocyanate component. Component A1 comprises a triurethane triol A1.1 and a compound A1.2 selected from the group consisting of polyether polyol, polyester polyol, polyether carbonate polyol, and polyether ester polyol. Also disclosed is a rigid PUR/PIR foam, an insulating material, a composite element, and a mixture.

Abstract: In a process for producing polyoxymethylene-polyalkylene oxide block copolymers comprising the step of polymerizing an alkylene oxide in the presence of an OH-terminated polyoxymethylene polymer and a catalyst, the polyoxymethylene polymer has a number-average molecular weight Mn determined after derivatization with propylene oxide and gel permeation chromatography against polystyrene standards with tetrahydrofuran as the eluent of ?1100 g/mol to ?2300 g/mol and the ratio of alkylene oxide to polyoxymethylene polymer is ?0.05 mol/g. The invention further relates to copolymers obtainable by the process, to a process for producing polyurethane polymers using these copolymers and to polyurethanes obtainable therefrom.

Abstract: A method for producing a prepolymer for the production of an integral polyurethane foam is provided. The prepolymer is or can be obtained by reaction of a composition that contains the following components: component A containing a polyoxymethylene-polyoxyalkylene block copolymer having a hydroxyl number of 20 mg KOH/g to 200 mg KOH/g as component Al, component B containing di- and/or polyisocyanates with an NCO content of 15 to 45 wt.-% relative to component B, 0.04 to 1.0 wt.-%, relative to the composition, a proton acid as component C, and optionally a component D that contains auxiliary agents, at a characteristic number of 450 to 850. The invention further relates to the prepolymer obtained by the method, to an integral polyurethane foam based on the prepolymer, and to the use thereof.

Abstract: The present invention relates to a process for preparing a polyester-polyether polyol block copolymer by reaction of an H-functional starter substance with lactone in the presence of a catalyst to afford a polyester followed by reaction of the polyester from step i) with alkylene oxides in the presence of a catalyst (B), wherein the lactone is a 4-membered lactone. The invention further relates to the polyester-polyether polyol block copolymer obtainable by the present process.

Abstract: The invention relates to a method for producing a polyoxymethylene polyoxyalkylene block copolymer, said method including the process of reacting a polymer formaldehyde compound with alkylene oxide in the presence of a double metal cyanide (DMC) catalyst and an H-functional starter substance, wherein the theoretical molar mass of the polymer formaldehyde compound is lower than the theoretical molar mass of the H-functional starter substance, and the polymer formaldehyde compound has at least one terminal hydroxyl group, the theoretical molar mass of the H-functional starter substance being at least 500 g/mol. In the method according to the invention, a mixture i) is provided comprising the DMC catalyst and the H-functional starter substance in step (i); the polymer formaldehyde compound is then added to the mixture (i) in step (ii), thereby forming a mixture (ii); and the alkylene oxide is added in step (iii), step (ii) being carried out at the same time as or prior to step (iii).

Abstract: A process for producing polyoxymethylene polymers comprises the reaction of aqueous formaldehyde solution with an aqueous solution of a base, wherein A) a starter solution comprising formaldehyde is initially charged and B) an aqueous formaldehyde solution and a base are added to the starter solution to obtain a reaction mixture. The starter solution in step A) has a temperature of ?40° C. to ?46° C. and the additions of the solutions in step B) are performed at a temperature of the reaction mixture of ?40° C. to ?46° C. The base is an alkali metal hydroxide and/or an alkaline earth metal hydroxide and the molar ratio of formaldehyde to base is ?55:1 to ?90:1 based on the total amounts of formaldehyde and base employed in the process. The base in step B) is added in aqueous solution.

Abstract: The invention relates to a process for producing a polyester by reacting a H-functional starter substance with a lactone in the presence of a catalyst, wherein the H-functional compound has one or more free carboxyl groups, wherein the lactone is a four-membered ring lactone, and wherein the catalyst is a Brönsted acid or a double metal cyanide (DMC) catalyst. The invention also relates to the polyester that can be obtained by the present invention.

Abstract: The present invention relates to a method for producing flexible polyurethane foams based on polyoxymethylene-polyoxyalkylene block copolymers. The invention also relates to the use of the flexible polyurethane foams thus produced and their use for producing furniture upholstery, textile inlays, mattresses, automobile seats, headrests, armrests, sponges, foam sheets for use in automobile parts such as roof linings, door panel upholstery, seat covers and technical components. The invention finally relates to a two-component system for producing flexible polyurethane foams.

Abstract: A process for producing rigid PUR/PIR foams comprising A1 an isocyanate-reactive component, A2 a flame retardant, A3 a blowing agent, A4 a catalyst, A5 optionally auxiliaries and additives, and B an organic polyisocyanate component. Component A1 comprises a triurethane triol A1.1 and a compound A1.2 selected from the group consisting of polyether polyol, polyester polyol, polyether carbonate polyol, and polyether ester polyol. Also disclosed is a rigid PUR/PIR foam, an insulating material, a composite element, and a mixture.

Abstract: The present invention relates to a method for producing flexible polyurethane foams based on polyoxymethylene-polyoxyalkylene block copolymers. The invention also relates to the use of the flexible polyurethane foams thus produced and their use for producing furniture upholstery, textile inlays, mattresses, automobile seats, headrests, armrests, sponges, foam sheets for use in automobile parts such as roof linings, door panel upholstery, seat covers and technical components. The invention finally relates to a two-component system for producing flexible polyurethane foams.

Abstract: A subject of the invention is a method for producing a polyetherester polyol by addition of alkylene oxide and lactone to H-functional starter substance in the presence of a double metal cyanide catalyst, wherein a suspension medium containing no H-functional groups is first initially charged in a reactor, and an H-functional starter substance is subsequently continuously metered in to the reactor during the reaction, and wherein the lactone is a 4-membered cyclic lactone. A further subject is also the polyetherester polyol obtainable according to the method according to the invention, and also polyurethanes which can be produced therefrom.

Abstract: The present invention relates to the use of diblock copolymers as surfactants, and to a method for producing diblock copolymers, containing a hydrocarbon-containing block A and a polyether carbonate-containing block B, by attaching alkylene oxide and carbon dioxide to H-functional starters in the presence of a double metal cyanide catalyst, characterized in that the H-functional starter has an OH functionality of 1, and the H-functional starter is selected from one or more compounds of the group of monofunctional alcohols having 10 to 20 carbon atoms, and no further catalyst is used in addition to the DMC catalyst.

Abstract: A method for the reduction organic molecules comprising a Ruthenium-Triphosphine complex with aromatic ligands at the phosphors which are ortho or meta substituted.

Abstract: A method for the reduction organic molecules comprising a Ruthenium-Triphosphine complex with aromatic ligands at the phosphors which are ortho or meta substituted.

Abstract: A method for the reduction organic molecules comprising a Ruthenium-Triphosphine complex with aromatic ligands at the phosphors which are ortho or meta substituted.

Abstract: A method for the reduction organic molecules comprising a Ruthenium-Triphosphine complex with aromatic ligands at the phosphors which are ortho or meta substituted.