Abstract: The invention relates to a process for the preparation of polyisocyanates with dimer, trimer and/or allophanate and optionally urethane structure.

Abstract: The invention relates to a process for the preparation of polyisocyanates with dimer, trimer and/or allophanate and optionally urethane structure.

Abstract: The invention relates to a method for producing a polyurethane dispersion, comprising the steps: I) providing polyurethane polymers and/or polyurethane prepolymers A) in a liquid phase comprising a first solvent, which solvent is miscible with water and has a lower boiling point than water; II) in the event that isocyanate functional polymers or isocyanate functional prepolymers were provided in step I): adding NCO-reactive compounds such that, at least in part, a reaction with the polymers or prepolymers occurs; III) distilling off the first solvent, which is miscible with water, such than an aqueous polyurethane dispersion is obtained; wherein the liquid phase in step I) still comprises water and/or after step II), water is added to the mixture obtained according to step II). Foam bubbles created during step III) are contacted at least temporarily by a second solvent. The first and second solvents are preferably acetone.

Abstract: The invention relates to a method for producing a polyurethane dispersion, having the steps of: I) providing isocyanate-functional prepolymers A) in a liquid phase comprising a solvent which can be mixed with water and which has a lower boiling point than water and II) adding NCO-reactive compounds to the isocyanate-functional prepolymers from step I) such that a reaction with the prepolymers is at least partly produced; wherein the liquid phase in step I) additionally comprises water and/or after step II), water is added to the mixture obtained in step II). A pressure p1 is applied to the liquid mixture with the isocyanate-functional prepolymers A) prior to and/or while carrying out step II), wherein p1 is less than the local atmospheric pressure present at said point in time. The pressure p1 is selected such that in step II), ?50 mass. % (preferably >0 mass. % to ?mass. %, more preferably ?0.1 mass. % to ?30 mass. % in particular ?1 mass. % to ?10 mass.

Abstract: The invention relates to a process for isocyanate modification which includes reacting a) at least one organic isocyanate having an NCO functionality greater than or equal to 1, b) a catalyst comprising at least one phosphonium salt comprising at least one cycloalkyl substituent bonded directly to a P atom of a phosphonium cation, c) optionally a solvent, and d) optionally additives. The present invention also relates to a catalyst for isocyanate modification comprising at least one phosphonium salt comprising at least one cycloalkyl substituent bonded directly to a P atom of a phosphonium cation.

Abstract: The invention relates to a method for modifying isocyanates using catalysts having a water content not exceeding 1,000 ppm.

Abstract: The application relates to a catalyst kit comprising a trimerisation catalyst for the asymmetric trimerisation of polyisocyanates and a catalyst poison for the trimerisation catalyst, which is characterised in that the trimerisation catalyst and the catalyst poison each have a water content of at most 0.5 wt %. The application furthermore relates to the use of the catalyst kit for the preparation of polyisocyanates containing iminooxadiazinedione groups by oligomerisation of monomeric di- and/or triisocyanates and a process for the preparation of polyisocyanates containing iminooxadiazinedione groups.

Abstract: The invention relates to a process for isocyanate modification which includes reacting a) at least one organic isocyanate having an NCO functionality greater than or equal to 1, b) a catalyst comprising at least one phosphonium salt comprising at least one cycloalkyl substituent bonded directly to a P atom of a phosphonium cation, c) optionally a solvent, and d) optionally additives. The present invention also relates to a catalyst for isocyanate modification comprising at least one phosphonium salt comprising at least one cycloalkyl substituent bonded directly to a P atom of a phosphonium cation.

Abstract: The invention relates to a method for modifying isocyanates using catalysts having a water content not exceeding 1,000 ppm.

Abstract: The present invention relates to an improved process for the preparation of polyisocyanates with a biuret structure by continuous reaction of excess amounts of organic diisocyanates having exclusively aliphatically and/or cycloaliphatically bonded isocyanate groups with organic diamines having exclusively aliphatically and/or cycloaliphatically bonded primary amino groups at elevated temperatures by 2-stage addition of the isocyanate component.

Abstract: The invention relates to a new industrial process for producing low-monomer-content organic polyisocyanates by oligomerization of organic diisocyanates in a two-phase system.

Abstract: The invention relates to a process for isocyanate modification which includes reacting a) at least one organic isocyanate having an NCO functionality greater than or equal to 1, b) a catalyst comprising at least one phosphonium salt comprising at least one cycloalkyl substituent bonded directly to a P atom of a phosphonium cation, c) optionally a solvent, and d) optionally additives. The present invention also relates to a catalyst for isocyanate modification comprising at least one phosphonium salt comprising at least one cycloalkyl substituent bonded directly to a P atom of a phosphonium cation.

Abstract: The present invention relates to an improved process for the preparation of polyisocyanates with a biuret structure by continuous reaction of excess amounts of organic diisocyanates having exclusively aliphatically and/or cycloaliphatically bonded isocyanate groups with organic diamines having exclusively aliphatically and/or cycloaliphatically bonded primary amino groups at elevated temperatures by 2-stage addition of the isocyanate component.

Abstract: The invention relates to a novel process for conditioning isocyanates. The purpose of conditioning of isocyanates or of mixtures of isocyanates is to remove organophosphorus components in a suitable manner such that the organophosphorus compounds no longer interfere with processing of the isocyanates.

Abstract: The invention relates to a new industrial process for producing low-monomer-content organic polyisocyanates by oligomerization of organic diisocyanates in a two-phase system.

Abstract: The present invention relates to novel low-monomer-concentration, low-viscosity solutions of diisocyanatotoluene-based isocyanatoisocyanurates in branched dialkyl phthalates as environmentally acceptable plasticizers for polyvinyl chloride, to a process for preparation of these solutions, and to their use as adhesion-promoting additives for coating compositions based on plasticized polyvinyl chloride.

Abstract: The invention relates to a novel process for conditioning isocyanates. The purpose of conditioning of isocyanates or of mixtures of isocyanates is to remove organophosphorus components in a suitable manner such that the organophosphorus compounds no longer interfere with processing of the isocyanates.

Abstract: The invention relates to an arrangement comprising at least two different electronic semiconductor circuits (HS) in which each of the semiconductor circuits (HS) is a component made of semiconductor material and which has an electrically active surface and electronic contacts, and corresponding contacts of the semiconductor circuits are connected to one another in an electrically conductive manner. In order to simplify production, the semiconductor circuits (HS) are produced in a common support (12) made of semiconductor material and are connected to one another in an electrically conductive manner. Electrically conductive contacts (18) that are connected to the semiconductor circuits (HS) are produced on the surface of the support (12) by metallizing the support. Said support (12) has an expansion (13), which is made of the same material, forming a unit with the same, and which is provided for accommodating additional switching elements or components.

Abstract: The present invention relates to a process for preparing polyisocyanates containing acylurea groups by reacting isocyanates corresponding to formula (I) R—(NCO)n,??(I) wherein R represents an n-valent linear or branched aliphatic group or cycloaliphatic group having 4 to 30 carbon atoms or an aromatic group having 6 to 24 carbon atoms and n is 1, 2, 3 or 4, with aliphatic and/or aromatic carboxylic acids in the presence of a metal salt catalyst at a temperature of 20 to 220° C. The present invention also relates to the reaction products (polyisocyanates) prepared by this process and to their use as binders for polyurethane coating compositions.

Abstract: The invention relates to a novel process for preparing low-monomer-content trimers based on 2,4- and/or 2,6-diisocyanatotoluene (TDI). A catalytic trimerization is carried out in a mixture of from 20 to 80% by weight of a diisocyanate component containing at least 80% by weight of 2,4- and/or 2,6-diisocyanatotoluene, from 20 to 80% by weight of solvent, and 0–20% by weight of an alcohol component, and also phenolic catalysts containing dialkylamino-methyl groups. In the course of ongoing trimerization, in one or more steps, additional monomeric 2,v4-diisocyanatotoluene is metered in.