摘要:
There are described aqueous dispersions of polyurethane resins, the production thereof and their use in aqueous coating agents, said dispersions being obtainable in aqueous or non-aqueous phase froma) polyurethane resins with at least one CH acidic group, an ionic or non-ionic hydrophilic group and, optionally, OH and/or NH groups, byb) introduction of olefinic double bonds by reaction withb.sub.1) compounds with a CH acidic group and an olefinic double bond, and/orb.sub.2) compounds with an olefinic double bond and also a group that is capable of reacting with CH acidic groups, and/orb.sub.3) compounds with an olefinic double bond and also a group that is capable of reacting with OH or NH groups, orb.sub.4) formaldehyde,whereupon, optionally, conversion into the aqueous phase and radical polymerization are effected.
摘要:
An aqueous coating composition which is self-drying or is crosslinked by external agents, processes and dispersions for its preparation and its use. The coating composition comprises:I) 40 to 100% by weight of a film-former in the form of an aqueous dispersion of one or more polyurethane resins having a number-average molecular mass (Mn) of from 2500 to 1,000,000 and a content of ionic groups, groups which can be converted to ionic groups, and/or hydrophilic groups of from 5 to 200 meq per 100 g of solid resin, and at least one CH-acid group per molecule and a OH-number of 0 to 100, wherein some or all of the Ch-acid groups can be reacted with one ore more compounds which are able to react with at least two CH-acid groups for chain-lengthening, andII) 60 to 0% by weight of one or more crosslinkers based on compounds which can react with at least two CH-acidic groups, based on formaldehyde condensation resins and/or polyisocyanates containing free or blocked isocyanate groups,the percentages by weight of I) and II) relating to the resin solids content and adding up to 100% by weight, and optionally pigments, fillers, organic solvents and/or conventional coating additives.
摘要:
Coating media and their use in processes for producing single-layer and multi-layer coatings are described. The coating media contain an aqueous mixture comprisingI. 99-70% by weight of a mixture ofA) 50-100% by weight of one or more binder vehicles which at least in part contain ionic groups,B) 0-50% by weight of one or more crosslinking agents, which at least in part may contain ionic groups, for binder vehicle A), wherein the ionic groups which are present have the same charge as those of component A), andII. 1-30% by weight of one or more binder vehicles (component C), which are miscible both with the binder vehicles of component A) at the storage temperature and with each other at the curing temperature of the coating media and which contain ionic groups, the charge of which is opposite to the charge of the ionic groups of component I), wherein the percentages by weight are given with respect to the weight of resin solids in each case and wherein the proportions of components I) and II) are matched to each other so that 0.5 to 70% of the number of charges of the ionic groups of I) are neutralised by the charges of the ionic groups of II), andIII. customary lacquer additives and/or pigments and/or extenders, and optionally one or more customary lacquer solvents.
摘要:
A process and a coating medium for producing a decorative multilayer coating on a substrate, wherein a base lacquer coat is applied and is overpainted with a transparent lacquer coat, wherein an aqueous, self-crosslinking base lacquer is used, which contains, as a binder vehicle, an aqueous polyurethane resin dispersion based on a polyurethane resin having a number average molecular weight (Mn) of 2500 to 120,000, a content of 10 to 400 mmole of lateral and/or terminal hydroxyl and/or R'O groups bonded to silicon, where R'=a C.sub.1 to C.sub.8 alkyl or C(O)R''', and R'''=a C.sub.1 to C.sub.10 alkyl, per 100 g solid resin, a hydroxyl number of 0 to 150, wherein hydroxyl groups bonded to silicon are not included in the calculation of the OH number, and a content of ionic groups, groups convertible into ionic groups and/or hydrophilic groups of 5 to 200 mEqu per 100 g solid resin.
摘要:
Aqueous dispersion of one or more polyurethane resins with a number average molecular weight (Mn) of 2500 to 1000000, a content of 2 to 150 mmol of siloxane linkages (--Si--O--Si--) per 100 g of solid resin, a hydroxyl value of 0 to 100 and a content of ionic groups, groups convertible into ionic groups and/or hydrophilic groups of 5 to 200 mEq per 100 g of solid resin and the process for the production thereof by chain extension of a polyurethane prepolymer containing ionic groups, groups capable of ion formation and/or hydrophilic groups which has at least one group R'OSi-- in which R'=C.sub.1 to C.sub.8 alkyl or C(O)R"' and R"'=C.sub.1 to C.sub.10 alkyl by the addition of water. The aqueous dispersion is suitable for aqueous coating compositions which are suitable in particular for multilayer lacquer coatings.
摘要:
A method or producing multilayer coatings, more particularly for lacquering of motor vehicles in which at least three immediately adjacent layers with alternating effective charge of the used binders are applied. The coating agents can be made polar e.g. by using resins containing ionic groups.
摘要:
A process for preparing a multi-layer coating on an electrically nonconductive surface of a substrate, which comprises (A) applying over the surface an aqueous dispersion having a pH of from 5 to 8 when not containing a metallic pigment, the dispersion containing of from 15% to 20% wt. based on the dispersion of a base coat resin without metallic pigments then having a nonvolatile content of from about 30% to about 50% wt. based on the base coat resin of (i) from 75% to 98% wt. based on base coat resin solids of one or more partially or completely acid neutralized cationic, polyurethane, and polyurethane-urea resins, having a OH number of up to 450, and an amine number of from 20 to 200, and (ii) from 2% to 25% wt. based on base coat resin solids of one or more of an amine-formaldehyde condensation resin alone or in admixture with a blocked polyiisocyanate in either case having at least two groups per molecule being reactive with one or more of amino, OH.sup.-, urethane, and urea groups in (i), the aqueous dispersion further containing one or more of a pigment, a filler, and a lacquer additive, and up to 15% wt. based on the dispersion of an organic solvent for said resin, the ratio of pigment and filler to the resin solids being 0.05-1.2:1, and (B) then applying a clear anionic lacquer coat in a solution in water or in an organic solvent of a clear lacquer powder, said base coat and said clear lacquer coat being cured together at a temperature below 160.degree. C.
摘要:
A process for producing a repair coating This invention relates to a process for producing a multi-layer repair coating by the application of a transparent clear lacquer coat, which is unpigmented or which contains colourless pigment, to a predried or hardened colour- and/or effect-imparting base pigment coat, or by the application of a pigmented covering lacquer coat to an optionally precoated substrate. Binder vehicles which are hardenable exclusively by radical polymerisation are used for the production of the transparent clear lacquer coat or of the pigmented covering lacquer coat, and hardening is effected by means of pulsed, high-energy UV radiation.
摘要:
A process for the preparation of a multi-layer coating wherein a colour- and/or special effect-imparting base lacquer coating compound is applied to a substrate optionally precoated with a primer and/or primer surfacer coating compound and/or further coating compounds and a clear lacquer layer is then applied to the colour- and/or special effect-imparting base lacquer layer, wherein the colour- and/or special effect-imparting base lacquer coating compound used is one which contains binders which can be cured by free-radical and/or cationic polymerisation under the action of high-energy radiation.
摘要:
Method of lacquering a substrate by applying a clear-lacquer coating compound to a precoated substrate or a one-coat top lacquer coating compound to an optionally precoated substrate, followed by curing, the substrate being a motor-vehicle body or parts thereof, in which the substrate is subjected, after the application of the clear-lacquer coating compound or one-coat top lacquer coating compound, optionally to a drying phase and the curing is then performed by irradiation with NIR radiation having the wavelength from 760 to 1500 nm.