Abstract: The invention relates to a continuous method for producing an isocyanurate-containing isocyanate mixture, in which in a step a) a mixture of a first and a second isocyanate component and an isocyanate group trimerization catalyst is provided; in a step b) the mixture obtained in step a) is reacted in a first residence time zone at an elevated temperature; in a step c), the reaction mixture obtained in step b) is further heated in a second residence time zone, optionally after adding a stopper; and in a step d), the reaction mixture obtained in step c) is cooled down in a third residence time zone by way of lowering the temperature, thus obtaining the desired isocyanurate-containing isocyanate mixture.

Abstract: The invention relates to a continuous method for producing an isocyanurate-containing isocyanate mixture, in which in a step a) a mixture of a first and a second isocyanate component and an isocyanate group trimerization catalyst is provided; in a step b) the mixture obtained in step a) is reacted in a first residence time zone at an elevated temperature; in a step c), the reaction mixture obtained in step b) is further heated in a second residence time zone, optionally after adding a stopper; and in a step d), the reaction mixture obtained in step c) is cooled down in a third residence time zone by way of lowering the temperature, thus obtaining the desired isocyanurate-containing isocyanate mixture.

Abstract: The invention relates to a process for preparing liquid, storage-stable isocyanate mixtures having carbodiimide (CD) and/or uretonimine (UI) groups or prepolymers derived therefrom, wherein (i) in a first step, a starting isocyanate which is an organic isocyanate or a mixture of two or more organic isocyanates is partly carbodiimidized with a catalyst K of the formula cyclo-C4H6P(O)R, where the substituent R is a saturated or unsaturated, optionally substituted, especially halogen-substituted, organic radical, and then (ii) in a second step, the carbodiimidization reaction is stopped at a temperature of ?80° C. by adding a stopper, the stopper used being an organic silane S of the general formula HnSiX4-n, where n is a natural number in the range from 1 to 3, where X is a saturated or unsaturated, optionally substituted, especially halogen-substituted, organic radical.

Abstract: A method for producing a composition comprising polycarbodiimide, comprising the step of the reaction of a reaction mixture which contains an aromatic polyisocyanate and a carbodiimidising catalyst, wherein, before the reaction, the aromatic polyisocyanate is treated at a temperature of ?80° C. to ?150° C. and a pressure of ?1 mbar to ?500 mbar by passing through an inert gas and/or during the reaction, the reaction mixture is treated at a temperature of ?80° C. to ?150° C. and a pressure of ?1 mbar to ?500 mbar by passing through an inert gas and wherein the content of hydrolysable chlorine in the reaction mixture is ?10 ppm.

Abstract: The invention relates to a process for preparing liquid, storage-stable isocyanate mixtures having carbodiimide (CD) and/or uretonimine (UI) groups or prepolymers derived therefrom, wherein (i) in a first step, a starting isocyanate which is an organic isocyanate or a mixture of two or more organic isocyanates is partly carbodiimidized with a catalyst K of the formula cyclo-C4H6P(O)R, where the substituent R is a saturated or unsaturated, optionally substituted, especially halogen-substituted, organic radical, and then (ii) in a second step, the carbodiimidization reaction is stopped at a temperature of ?80° C. by adding a stopper, the stopper used being an organic silane S of the general formula HnSiX4-n, where n is a natural number in the range from 1 to 3, where X is a saturated or unsaturated, optionally substituted, especially halogen-substituted, organic radical.

Abstract: The invention relates to a method for producing rigid polyurethane-polyisocyanurate (PUR/PIR) foams using partially trimerized isocyanate blends. The invention further relates to the rigid polyurethane-polyisocyanurate foams obtainable by said method and to the use thereof in manufacturing composite elements made of the rigid polyurethane-polyisocyanurate foams and suitable coatings. The invention also relates to the composite elements obtainable thereby.

Abstract: A method for producing a composition comprising polycarbodiimide, comprising the step of the reaction of a reaction mixture which contains an aromatic polyisocyanate and a carbodiimidising catalyst, wherein, before the reaction, the aromatic polyisocyanate is treated at a temperature of ?80° C. to ?150° C. and a pressure of ?1 mbar to ?500 mbar by passing through an inert gas and/or during the reaction, the reaction mixture is treated at a temperature of ?80° C. to ?150° C. and a pressure of ?1 mbar to ?500 mbar by passing through an inert gas and wherein the content of hydrolysable chlorine in the reaction mixture is ?10 ppm.

Abstract: The invention relates to polyurethanes that can be obtained by reacting a prepolymer based on diphenylmethane diisocyanate (MDI) with compounds that have NCO-reactive groups, and to use thereof.

Abstract: The present invention relates to NCO-terminated prepolymers that are stable to sedimentation, to a process for the production of these NCO-terminated prepolymers, and to the production of polyurethanes from these NCO-terminated polymers.

Abstract: The present invention relates to NCO-terminated prepolymers that are stable to sedimentation, to a process for the production of these NCO-terminated prepolymers, and to the production of polyurethanes from these NCO-terminated polymers.

Abstract: The present invention relates to a process for the preparation of clear, storage-stable isocyanate-terminated prepolymers. These isocyanate-terminated prepolymers are based on hexanediolether carbonate. This invention also relates to the preparation of polyurethanes from these isocyanate-terminated prepolymers.