Abstract: The present invention relates to a polyurethane powder coating composition containingA) a binder component which is solid below 40.degree. C. and liquid above 130.degree. C. and has an OH number of 25 to 200 and a number average molecular weight of 400 to 10,000,B) a polyaddition compound which is solid below 40.degree. C. and liquid above 125.degree. C., contains uretdione groups and optionally free isocyanate groups and is prepared from aliphatic and/or cycloaliphatic diisocyanates andC) one or more catalysts containing N,N,N'-trisubstituted amidine groups which have an amidine group content (calculated as CN.sub.2 ; molecular weight=40) of 12.0 to 47.0 wt. %,provided that components A) and B) are present in amounts such that component B) has 0.6 to 1.4 isocyanate groups for each hydroxyl group present in component A) and the amount of component C) is 0.05 to 5 wt. %, based on the total weight of the coating composition.

Abstract: The present invention relates to a powder coating composition for the production of matt coatings containing as binderA) a component having hydroxyl groups,B) a polyisocyanate having blocked and optionally free isocyanate groups,C) a component having carboxyl groups and/or carboxylic anhydride groups and contains one or more of the following:C1) aliphatic and/or cycloaliphatic dicarboxylic acids having 4 to 20 carbon atoms,C2) monomeric and/or polymeric anhydrides of dicarboxylic acids C1) andC3) aliphatic hydroxycarboxylic acids having 4 to 18 carbon atoms, andD) a component which has groups that are reactive with carboxyl groups and/or carboxylic anhydride groups wherein components A), B), C) and D) are present in amounts such that1) 0.6 to 1.4 isocyanate groups of component B) are present for each hydroxyl group of component A),2) 0.3 to 1.

Abstract: The present invention relates to a powder coating composition for the production of matte coatings, containingA) a hydroxyl group-containing component,B) an addition polymerization compound which is based on aliphatic and/or cycloaliphatic diisocyanates and contains uretdione groups,C) a component which contains carboxyl and/or carboxylic acid anhydride groups and is selected fromC1) aliphatic and/or cycloaliphatic dicarboxylic acids containing 4 to 20 carbon atoms,C2) monomeric and/or polymeric anhydrides of the acids C1) which may optionally be modified andC3) aliphatic hydroxycarboxylic acids containing 4 to 18 carbon atoms, andD) a component which contains groups which are reactive with carboxyl and/or carboxylic acid anhydride groups,provided that components A), B), C) and D) are present in amounts such that 0.6 to 1.4 isocyanate groups of component B) are present for each hydroxyl group of component A), 0.3 to 1.

Abstract: The present invention relates to novel polysiloxane-polyether-based copolymers which contain T units and comprise randomly linked organopolysiloxane units and linear polyether units, to a method for their preparation and their use.

Abstract: The present invention relates to polyaddition compounds that are solid below 40.degree. C. and liquid above 125.degree. C. and contain, based on the weight of the polyaddition compounds,a) 0 to 2% by weight of free isocyanate groups (calculated as NCO; molecular weight=42),b) 3 to 16% by weight of uretdione groups (calculated as C.sub.2 N.sub.2 O.sub.2 ; molecular weight=84),c) 10 to 22% by weight of urethane groups (calculated as --NH--CO--O--; molecular weight=59).d) 0 to 20% by weight of carboxylic add ester groups (calculated as CO--O--; molecular weight=44) ande) of 0 to 25% by weight of carbonate groups (calculated as --O--CO--O--; molecular weight=60),provided that the total content of carboxylic add ester groups and carbonate groups is at least 1% by weight.

Abstract: Polyisocyanate polyaddition products which are solid below 40.degree. C. and liquid above 125.degree. C., contain uretdione and urethane groups and have a content of at least 1 wt. % of urethane groups obtained from the reaction of dimeric diols with isocyanate groups; a method of producing the these products by the reaction of polyisocyanates containing uretdione groups with dimeric diols; and the use of these polyaddition compounds as the starting component in the manufacture of polyurethane plastics, particularly as the cross-linking component in thermally cross-linkable two-component polyurethane powder coating compositions.

Abstract: Polyisocyanate-modified dicarboxylic (poly)anhydrides which are solid below 40.degree. C., liquid above 120.degree. C. and based on the reaction product of organic polyisocyanates with more than equivalent quantities, based on the NCO/COOH reaction, of dicarboxylic (poly)anhydrides containing free carboxyl groups and optional subsequent modification of the reaction product with less than equivalent quantities, based on the anhydride groups, of anhydride-reactive amino and/or hydroxyl groups; and powder coating compositions containing as binder these polyisocyanate-modified dicarboxylic (poly)anhydrides as curing agents for polyepoxides.

Abstract: Powder coating compositions based on A) copolymers prepared from olefinically unsaturated monomers, containing epoxide and anhydride groups and having a glass transition temperature T.sub.g of 30.degree. to 80.degree. C., an average molecular weight M.sub.n of 1,000 to 6,000 and a molecular weight distribution M.sub.w /M.sub.n of 2.5 to 10.0, B) a hardener component selected from (i) (cyclo)aliphatic dicarboxylic acids, (ii) anhydrides of such dicarboxylic acids, (iii) polyol-modified polymeric anhydrides of such dicarboxylic acids and (iv) aliphatic hydroxycarboxylic acids and optionally C) additional crosslinking agents in the form of polyaddition products having uretidione groups, and the use of these compositions for coating heat-resistant substrates.

Abstract: A powder coating composition for the production of non-yellowing, flexible coatings which contains a mixture of a polyisocyanate component which contains one or more lacquer polyisocyanates having free (unblocked) isocyanate groups bound to primary and/or secondary carbon atoms and a polyol component containing one or more polyhydroxyl compounds selected from polyhydroxy polyurethanes, polyhydroxy polyacrylates and polyhydroxy polyesters, wherein at least 50% of the hydroxyl groups are bound to secondary or tertiary carbon atoms; and its use for coating heat-resistant substrates, in particular as clear coating compositions for automobiles.

Abstract: The present invention relates to a powder coating composition having a glass transition temperature of 20.degree. to 80.degree. C. and containing(A) 56 to 86.9% by weight of a polyacrylate polyol component having a hydroxyl number of 30 to 155 and a glass transition temperature of 30.degree. to 120.degree. C.,(B) 0.1 to 9% by weight of a polyester polyol component having a hydroxyl number of 40 to 180 and a glass transition temperature of -40.degree. to 80.degree. C.,(C) 13 to 35% by weight of a polyisocyanate component having a glass transition temperature of -40.degree. to 60.degree. C.

Abstract: A powder coating composition which is curable at 120.degree. to 150.degree. C. and contains A) one or more copolymers prepared from olefinically unsaturated monomers and containing epoxy groups and optionally hydroxyl groups, B) one or more curing agents containing carboxylic acid or carboxylic acid anhydride groups, and C) one or more polyaddition compounds which contain uretdione groups, have a melting point or range of 40.degree. C. to 120.degree. C. and are prepared from (cyclo)aliphatic diisocyanates; and its use for coating of heat-resistant substrates, especially automotive substrates.

Abstract: The present invention relates to polyisocyanate mixtures which are solid below 40.degree. C. and liquid above 125.degree. C. and which havea) an average isocyanate functionality of at least 2.1,b) a content of free isocyanate groups bonded to tertiary (cyclo)aliphatic carbon atoms (calculated as NCO; molecular weight=42) of 5 to 22 wt. %,c) a urethane group content calculated as --NH--CO--O--; molecular weight=59) of 2 to 30 wt. %,d) an isocyanurate group content (calculated as C.sub.3 N.sub.3 O.sub.3 ; molecular weight=126) of 0 to 30 wt. % ande) a carboxylic acid ester group content (calculated as --CO--O--; molecular weight=44) of 0 to 25 wt. % and/orf) a carbonate group content (calculated as --O--CO--O--; molecular weight=60) of from 0 to 34 wt. %with the proviso that the total amount of ester groups e) and carbonate groups f) is at least 2 wt. %.

Abstract: A process for the solvent-free production of hydroxy-functional copolymers by copolymerization of unsaturated monomers in a mixture of a polyester component and an unsaturated ester component as reaction medium, the use of the hydroxy-functional copolymers so obtained as binder component in polyurethane powder coatings, a powder coating based on these copolymers and its use for coating any heat resistant substrates.

Abstract: An aqueous coating composition is provided which comprises a film forming material based on water dilutable binders which are comprised of a mixture of (A) 90 to 40% by weight of hydroxyl group-containing polymer resin; (B) 10 to 60% by weight of polyurethane dispersion and (C) pigments; as well as optionally conventional solvents, auxiliary agents, and additives. The process for the preparation of the coating composition and a method for the application of the coating composition are also described.

Abstract: A gas-blast switch having a hollow support insulator, and and at least one switching chamber housing supported thereon and within which there is arranged a set of fixed contacts, surrounded by a blast chamber, and a set of movable contacts. A blast nozzle coacts with the movable contacts and is connected with a pump device having a pump cylinder surrounding a pump chamber and movable with the movable contacts. The pump cylinder is displaceably arranged upon a stationary piston. A check valve opens towards the pump chamber. During the cut-on stroke pressurized gas is sucked by the valve into the pump chamber. The latter is connected by the check valve with a supply compartment communicating via inlets with the blast chamber and the internal space of the support insulator. A further valve is responsive to the pressure increase in the blast chamber, which valve, when responsive, interrupts the connection between the internal space of the support insulator and the inlets.