Abstract: The invention relates to the use of special mixtures of at least two polycarboxylic acids as crosslinker components for thermally curing powder-lacquer binding agents having groups that are capable of reacting with carboxyl groups. The mixtures include at least two polycarboxylic acids each melting above 95° C. and having up to 20 carbon atoms and consist of at least 5 wt. %, of the polycarboxylic acid with the lowest melting point and at least 10 wt. %, of the polycarboxylic acid with the highest melting point of all polycarboxylic acids present in the mixture to at least 5 wt. %. Additionally, the polycarboxylic acid mixture is a solid below 40° C. and a liquid above 160° C.

Abstract: The invention relates to novel compounds containing uretdione groups, to a process for preparing them by dimerizing aliphatic and/or cycloaliphatic isocyanates containing exclusively secondary and/or tertiary isocyanate groups and also to the use of uretdione polyisocyanates obtainable by this process from diisocyanates containing exclusively secondary and/or tertiary isocyanate groups as a starting component for polyurethane polymers, in particular as an isocyanate component in the preparation of uretdione powder coating crosslinkers.

Abstract: Blocked polyisocyanates and one-component stoving systems containing these blocked polyisocyanates, and the preparation thereof and their use for the preparation of lacquers, paints, adhesives and elastomers, wherein blocked polyisocyanates are prepared by reacting polyisocyanates with secondary amines corresponding to the formula wherein R1—R4 can be identical or different and denote hydrogen, C1–C6-alkyl or cycloalkyl, R5 denotes C1–C10-alkyl, C3–C10-cycloalkyl, y denotes a number from 2 to 8, and B represents wherein R6–R8 can be identical or different and independently of one another denote C1–6-alkyl and/or C3–C6-cycloalkyl, R9 denotes hydrogen or C1–6-alkyl or C3–C6-cycloalkyl.

Abstract: The invention relates to a process for preparing polyisocyanates having a high uretdione group content by phosphine-catalysed isocyanate oligomerization in the presence of organic carbonates and/or nitriles.

Abstract: The invention relates to the use of cycloalkylphosphines as catalysts for isocyanate dimerization and to a process for preparing polyisocyanates containing uretdione groups.

Abstract: The present invention relates to the use of sulphonamide salts as catalysts for oligomerizing isocyanates and also to a process for NCO oligomerization using the catalysts of the invention.

Abstract: A continuous process for making an acid functional blocked Isocyanate. The process includes continuously feeding and mixing a) one or more polyisocyanates; b) one or more hydroxycarboxylic acids; and c) one or more other isocyanate blocking agent; in a reactor at from 100-240° C. The method provides acid functional blocked Isocyanates useful as crosslinkers for powder coatings.

Abstract: The present invention is directed to blocked biuret group-containing polyisocyanate compositions, wherein the blocking agent is selected from the group consisting of di-C1-C12-alkyl and/or alkoxyalkyl malonates and acetoacetic acid C1-C12-alkyl and/or alkoxyalkyl esters.

Abstract: Polyaddition compounds containing uretdione groups prepared by reacting uretdione polyisocyanates formed from diisocyanates having exclusively secondary- and/or tertiary-attached isocyanate groups with a molar fraction of isocyanurate structures, based on the sum of uretdione groups and isocyanurate groups, of not more than 10%, with compounds reactive towards isocyanates. The polyaddition compounds can be use as a starting component in the preparation of polyurethane plastics, in particular as crosslinkers for heat-crosslinkable powder coating materials. The compounds may be used as starting components in the preparation of moldings and shaped parts, and as starting components in the preparation of coating materials and coatings.

Abstract: The present invention relates to polyurethane powder coating compositions containing A) a hydroxyl-functional binder component, which is solid below 40° C. and liquid above 130° C., has a content of carboxyl groups (calculated as COOH; molecular weight 45) of 0.5 to 2.0 wt. %, and contains at least one polymeric polyol having an OH number of 15 to 200 mg KOH/g and a number average molecular weight of 400 to 10,000 and B) a polyaddition compound which contains uretdione groups and optionally free isocyanate groups, is solid below 40° C. and liquid above 125° C., and is prepared from aliphatic and/or cycloaliphatic diisocyanates, C) at least one zinc compound as hardening catalyst, and D) a compound which has a number average molecular weight of 200 to 5000 and contains groups reactive to carboxyl groups, wherein i) components A) and B) are present in amounts such that 0.8 to 2.

Abstract: A method of dimerizing isocyanates including reacting the isocyanates in the presence of phosphines containing at least one directly phosphorus-attached bicyclic, cycloaliphatic radical. The polyisocyanate compositions obtained as described above can be used in mouldings, coating materials, adhesives, sealants or adjuvants that further include the polyisocyanate compositions and one or more materials selected from antioxidants, light stabilizers, pigments, fillers, additives, levelling assistance, defoamers and matting agents. The coating materials, adhesives or sealants can be used to coat substrates.

Abstract: Storage-stable blocked polyisocyanates prepared by reacting one or more polyisocyanates with one or more biuretizing agents and optionally, catalysts such that in the blocked end product there are 5-45 equivalent percent of biuret groups according to formula (I) based on the sum total of all free and blocked NCO groups; optionally modifying the resulting biuret polyisocyanates with the aid of isocyanate-reactive compounds and/or catalysts, with further reaction of free NCO groups; and subsequently blocking at least 95 mol percent of the remaining free NCO groups with a blocking agent according to the formula R1R2NH, where R1 and R2 independently of one another are aliphatic or cycloaliphatic C1-C12 alkyl radicals. The blocked polyisocyanates can be used to make polyurethane polymers and coating compositions, which can be used to coat substrates.

Abstract: Storage-stable Polyisocyanates based on aliphatic and/or cycloaliphatic diisocyanates including from 1 to 20% by weight of alkylamino groups of the formula R1R2N as a constituent of biuret groups, wherein R1 and R2 independently of one another are aliphatic or cycloaliphatic C1-C12 alkyl radicals, and where at least 95 mol % of the isocyanate groups are blocked with at least one blocking agent, and the polyisocyanates contain from 4.0 to 21.0% by weight of blocked and free NCO groups (calculated as NCO, molecular weight=42). The polyisocyanates are used to produce coating compositions, coatings, and coated substrates.

Abstract: Biuret group-containing polyisocyanates are produced having an isocyanate functionality of at least 4 are prepared by reacting polyisocyanates having a functionality of at least 2.8 with water as the biuretizing agent. Most preferably water is used as the sole biuretizing agent. The preparation is useful as a curing agent in crosslinkable coating compositions. The coating composition can be used as an automotive clearcoat over a conventional pigmented basecoat, or as a basecoat or monocoat or even as a primer or sealer when a suitable amount of pigment is incorporated therein.

Abstract: The present invention relates to the use of sulphonamide salts as catalysts for oligomerizing isocyanates and also to a process for NCO oligomerization using the catalysts of the invention.

Abstract: A process for preparing polyisocyanate-modified polycarboxylic acids by conversion of anhydride-group-free polycarboxylic acids with isocyanate-functional compounds. The process includes reacting A) an anhydride-group-free polycarboxylic-acid component with B) an isocyanate-functional component having an (average) isocyanate functionality of at least 1.8, at an equivalent ratio of carboxylic acid groups to isocyanate groups of from 1.2:1 to 120:1. The polyisocyanate-modified polycarboxylic acids are solid below 40° C. and liquid above 130° C., and have an average carboxylic acid functionality of at least 1.8, a content of free carboxylic acid groups of from 4.0 wt. % to 80.0 wt. % and a content of amide groups of from 0.4 wt. % to 32.5 wt. %.

Abstract: The invention relates to the use of special mixtures of at least two polycarboxylic acids as crosslinker components for thermally curing powder-lacquer binding agents having groups that are capable of reacting with carboxyl groups. The mixtures include at least two polycarboxylic acids each melting above 95° C. and having up to 20 carbon atoms and consist of at least 5 wt. %, of the polycarboxylic acid with the lowest melting point and at least 10 wt. %, of the polycarboxylic acid with the highest melting point of all polycarboxylic acids present in the mixture to at least 5 wt. %. Additionally, the polycarboxylic acid mixture is a solid below 40° C. and a liquid above 160° C.

Abstract: Blocked polyisocyanates and one-component stoving systems containing these, and the preparation thereof and their use for the preparation of lacquers, paints, adhesives and elastomers. The blocked polyisocyanates are prepared by reacting polyisocyanates with secondary amines.

Abstract: The invention provides novel solvent-free two-component polyurethane coating agents for preparing high quality yellowing-free coatings and a process for the preparation thereof. The coating agents include binder mixtures containing a polyisocyanate component with a viscosity at 23° C. of 2,000 to 150,000 mPas, a NCO content of 14 to 23 wt. % and a calculated mean NCO functionality of at least 2.8; a polyol component with a mean OH functionality <3, a viscosity at 23° C. of 5,000 to 150,000 mPas and a hydroxyl value of 400 to 700 mg KOH/g; and optionally one or more catalysts.

Abstract: Coating compositions based on aqueous polyurethane dispersions, a process for preparing such compositions and their use for producing soft feel coatings having low fog and VOC values. The aqueous coating compositions include at least one aqueous formulation of an ionically modified, substantially hydroxyl-free poylurethane and/or polyurethaneurea, at least one aqueous formulation of an ionically modified, hydroxyl-containing polyuerthane and/or polyurethaneurea, and at least on crosslinker.