USE OF HYDROSOLUBLE CIRCONIAL COMPOUNDS AS DRY ACCELERATORS IN COATING AGENTSAQUEOUSThe present invention relates to the use of water-soluble zirconium compounds as accelerators of drying in aqueous coating compositions. • Conventional systems for quick-drying coatings are usually carried by solvents. In these compositions of10 solvent-based coating, the speed of drying can be controlled by varying the solid content and / or the solvent. The aqueous coating compositions are environmentally friendly and in recent times have increasingly replaced their solvent-based counterparts. To prepare a coating composition carried by water,15 It is more normal to use polymer dispersions as the binder. A disadvantage of the aqueous coating compositions is the dependence of the drying rate on the temperature and atmospheric humidity. At a low atmospheric humidity, the drying speed is^^^ generally fast, in some cases even faster than in the case of the conventional coating compositions. With high atmospheric humidity and low temperatures, however, as for example in the morning and in the afternoon, and before or after the rain, the speed of drying is very slow, since the evaporation of water is impairedmainly. Said coatings then acquire resistance to rain only after very long residence times. Accelerated drying of aqueous coating compositions is particularly desirable for exterior applications, such as, for example, paints 5 for buildings, bridges, ships and pavement markings, as well as for exterior surfaces. For the quick drying aqueous coating compositions there are three different principles of practical relevance. In accordance with the principle of flocculation, the flocculation of the ionically stabilized binder is carried out either after the application of the coating composition, which comprises a polyamine and ammonia as a volatile base, as a result of the fact that the ammonia• is evaporated (US-A-5 527 853, EP-AO 594 321, EP-AO 728 822, EP-AO 409 459) or by virtue of the fact that, together with the coating composition, an acid solution is sprayed. (WO 94/29 391) = or a salt solution (EP-AO 200249, US-A-4571 415, US-A-5403 393). A change in the viscosity of the surface of the coating composition can be carried out by applying either a thickener f to the fresh coating, thereby producing an increase in theViscosity, as described, for example in EP-A-721 003, or a base to the fresh coating comprising a thickener, without which, however, it is not activated by the formulation of a low pH.
In the case of the water absorption method, substances that absorb water, such as silica gels, ion exchangers, polymer gels, etc. are used during the application of the coating composition. In the case of coating compositions where drying is activated by the evaporation of a volatile base such as ammonia, the scope of the invention is limited as a result, for example of odor contamination. The coating compositions which are brought into contact with salts after their application have the disadvantage that they are restricted for their use of weakly stabilized dispersions. The salts used should be sprayed as a solution with the coating composition or they should be applied subsequently by means of spraying or dispersing. In the case of the subsequent application of salts, in solid or dissolved form, considerable fractions can be washed which it carries out by means of rain, for example, thus severely preventing the efficiency of the method. The amounts of salt that have been washed out by rain usually pass to groundwater. As a consequence, this mode of drying is undesirable. EP-A-0 709 441 describes the use of zirconium compounds in paints and adhesives. The zirconium compounds are used as a drying material, an entanglement reagent, a thixotropic agent, a free radical scavenger in the decomposition reactions of the films ofcoating, and a substance that forms complex for ingredients that normally lead to spillage and / or discoloration of surfaces. Surprisingly, it has been found that coating compositions comprising one or more water-soluble zirconium compounds exhibiting highly accelerated drying. In particular, they do it at low temperatures. The binders present in the coating compositions surprisingly are not subject to any special requirements. For use according to the invention, the coating compositions contain, based on the binder, preferably up to50% by weight, particularly preferably from 0.5 to 10% by weight, and in particular from 1 to 5% by weight of zirconium compounds, calculated as zirconium oxide. The zirconium compounds used are preferably ammonium zirconium carbonate, zirconium acetoacetate, zirconium hydroxychloride, zirconium orthosulfate, zirconium propionate and / or potassium zirconium phosphate. Particular preference is given to the use of ammonium zirconium carbonate. Zirconium compounds can be added to the coating composition as solids and / or aqueous solutions. In addition to a binder, zirconium-containing coating compositions may, when appropriate, further comprise film formers, pigments, fillers (such as titanium dioxide, talc, calcite, dolomite, for example), thickeners for example, such as cellulose ethers, acrylic acid, polyurethane thickeners, dispersants, wetting agents, preservatives, emulsifiers and / or foam removers. The concentration of the pigment volume (PVC) is generally between 15 and 90%. To increase the stability of the coating composition it is possible, when appropriate, additionally to be from 0.1 to 5% by weight, preferably from 0.5 to 1% by weight, based on the binder, ionic and / or nonionic emulsifiers which are going to be added to it The binders present in the coating compositions generally comprise polymer dispersions which are based on homopolymers and / or copolymers. Suitable homopolymers and copolymers include all known homopolymers and copolymers obtainable in dispersion form. In a preferred embodiment, the copolymers contain from 70 to 99.7% by weight, based on the general amount of the monomers, of polymerizable and radically free olefinically unsaturated compounds from the group consisting of acrylates and methacrylates of (C1-C12) monoalcohols. , preferably monoalcohols (C1-C5), among the examples are methanol, ethanol, isopropanol, isobutanol, n-butanol, and 2-ethylhexyl alcohol, vinylaromatic monomers, vinyl esters of alkanemonocarboxylic acids (C1-C12), examples of the which are vinylacetate, vinylpropionate, vinyl n-butyrate, vinillaurate, ®VeoVa 9 and © VeoVa 10(Shell-Chemie, vinyl esters of Wd-dialkyl branched monocarboxylic acids), vinyl halides, examples include vinyl chloride and vinylidene chloride, V, 3-monoolefinically unsaturated nitriles, examples include acrylonitrile and methacrylonitrile, and the alkyl alkylesters of monoolefinically unsaturated and carboxylic acids, examples include di-n-butyl maleate and fumarate• di-n-butyl. The copolymers further contain preferably from 0.3 to 10% by weight, with particular preference from 0.5 to 5% by weight, based on theThe general amount of monomers, of V, 3-monoolefinically unsaturated monocarboxylic and dicarboxylic acids, among the examples are acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid, and their amides with or without substitution at the nitrogen atoms , examples of which are acrylamide, methacrylamide, N-methylolacrylamide and N-butoxymethacrylamide. It is also possible, from 0 to 20% by weight, preferably from 0.5 to 5% by weight, based on the general amount of monomers, of functional monomers, which are present in the copolymers, among the examples are monomers containing hydroxyl, such as hydroxyalkyl acrylates and methacrylates, especially methacrylateHydroxyethyl and hydroxypropyl methacrylate, and / or acetylacetoxy-containing monomers that improve wet-bonding, particularly allyl-acetoacetate, acetyl-acetoxyethyl-methacrylate and acetylacetoxybutylmethacrylate, and / or monomers with an interlacing action such as monomerscontaining epoxide groups and monomers containing xylan groups, particularly glycidylacrylate, vinyltrimethoxysilane and methacryloyloxypropyltrimethoxysilane, and / or nitrogen-containing monomers of the group consisting of polymerizable monomers containing an amino, ureido or n-heterocyclic group, examples of which are dimethylaminoethylacrylate and dimethylaminoethylmethacrylate, N- (2-methacryloylethyl) ethylene-urea, and / or monomers containing keto groups, examples which are diacetone-acrylamide, diacetonemethacrylamide, acrolein, and 2-butanonemethacrylate. In the self-crosslinking dispersions, the polymers containing keto groups can also comprise up to 5% by weight, based on the general entity of monomers, of a hydrazidecarboxylic• difunctional or polyfunctional, whose example is adipic hydrazide. Binders where appropriate, also comprise15 non-copolymerizable emulsifiers, protective colloids, additives, auxiliaries and / or crosslinkers. Suitable nonionic examples include alkyl polyglycol ethers and polypropylene oxide ethoxylation products. The• Suitable ionogenic emulsifiers include emulsifiersThese are mainly anionic such as alkali metal salts or alkyl ammonium salts, aryl or alkylarylsulfonates, alkyl, aryl or alkylaryl, alkyl, aryl or alkylaryl or alkyl, aryl or alkylarylphosphonate phosphates.
Suitable protective colloids include natural substances, such as gum arabic, starch, and alginates, for example, or modified natural substances, such as cellulose derivatives, for example, or synthetic polymers, such as polyvinyl alcohol and polyvinyl pyrrolidone, for example, or mixtures thereof. The coating compositions preferably comprise exterior plaster layer, interior plasters, exterior paints, interior paints, primers, wood coatings for road or road marking paints. In its broadest sense, the coating compositions of the present invention can also comprise adhesives, pastes, plaske, sealing compounds or pressure compensation coatings for exterior insulation and finishing systems. The zirconium-containing coating compositions can also comprise binders that do not contain additives, which can be used as fast-drying binders for all known purposes. The invention is described in more detail below with reference to the examples, without being restricted by the same.
A) Preparation of synthetic-ream plaster layers The synthetic-resin plaster layers described in the novel and comparative examples have the base formula indicated in Table 1.
COMPARATIVE EXAMPLE 1 Preparation of a layer of comparative plaster 1 that does not contain zirconium compoundThe composition of the comparative plaster layer 1 corresponds to the base formula indicated in Table 1 in which the binder used comprises a synthetic dispersion-Mowilith® resin.
• DM 2452 (Table 1, ingredient 8) of Clariant GmbH which has a solids content of 50%, a pH of 6, and no viscosity of 400 mPas. the basis ofThe monomer of this dispersion is formed with vinyl acetate, vinyl esters of Versatic® acid, and acrylates. To prepare the plaster layer, the water is initially introduced and the remaining ingredients are added in the established order,# mixing After the raw material has been introduced, the20 layer of plaster until it is completely homogeneous. To prepare the plaster layer, water is initially introduced and the ingredients are added in the established order,mixing After the raw materials have been introduced, the plaster layer is mixed until it becomes completely homogeneous.
TABLE 1 Base formula of a layer of synthetic-resin plasterEXAMPLE 1 Preparation of a layer of synthetic resin-containing plaster 1 containing zirconium5 The composition of the synthetic-resin plaster layer 1 differs from the base formula shown in Table 1, only in that it also contains 20 parts in an epso of a zirconium compound Bozefix• PAS5200 from Clariant GmbH. The binder used is the same synthetic resin dispersion as in comparative example 1. To prepare the plaster layer, bean is added and the remaining ingredients are added in the established order, mixing, the zirconium compound is added at the end. After the• Raw materials, the nelucide layer is mixed until it is completely homogeneous. COMPARATIVE EXAMPLE 2 Preparation of a comparative plaster layer 2 that does not contain zirconium compoundThe composition of the comparative plaster layer 2 corresponds to the base formula indicated in Table 1 where the binder is used which is a synthetic dispersion-resin Mowillith® LDM 1880 (Table 1, ingredient 8) of Clariant GmbH which has a content ofsolids of 55%, or a pH of 5 and a viscosity of 2000 mPas. The monomer base of this dispersion is formed with vinyl acetate and ethylene. The comparative plaster layer 2 is prepared in the same way as the composite plaster layer 1 as described in comparative example 1.
EXAMPLE 2 Preparation of a layer of synthetic resin-containing plaster 2 containing zirconiumThe composition of the resin-synthetic plaster layer 2 differs from the base formula indicated in Table 1 alone, which also contains 20 parts by weight of a zirconium compound Bozefix PAS5200 from Clariant GmbH. The binder used is the same synthetic resin dispersion as in comparative example 2. To prepare the plaster layer, water is introduced and the remaining ingredients are added in the established order, mixing, wherein the zirconium compound is added until the end. After the raw materials have been introduced, the plaster layer is mixed until it is completely homogeneous. B) Development of tests of the comparative plaster layers 1 and 2 and of the resin-containing plaster layers 1 and 2 containing zirconium.a) Preparation of the test samples The substrate, the comparative plaster coatings 1 and 2, the synthetic resin coatings 1 and 2, and the mold required, are conditioned in an acclimatization chamber at the test temperature of 5 ° C. At this temperature, the plaster layers are applied to a fiber cement panel with the dimensions 10 cm x 15 cm, using a pallet, and then they are stretched to the thickness of the grain, and are textured.b) Testing of the test samples After different drying times, at a test temperature of 5 ° C, the test samples are examined to check their degree of drying. Up to this point, the test samples are sprinkled each with 60 grams of water. The water spray is generated using a commercial atomizer. During the spraying operation, the test samples are placed in vertical position. The liquid that is spilled is collected quantitatively. Although the coating composition has not yet been dried, the test liquid washes the particles, and as a result acquires a whitish statement. The intensity of the statement allows that conclusions can be drawn about the drying state of the coating composition. The degree of drying of the plaster layers is evaluated according to the six listed in table 2.
TABLE 2 Classification of drying grades• The grades are dried from the comparative plaster coatings 1 and 2 and the synthetic plaster coatings 1 and 2 in accordance with the10 six classes of Table 2 after 4 and 7 hours of drying at a drying temperature of 5 ° C are indicated in Table 3.
• TABLE 3 Degrees of drying of the plastered layers investigated 15twentyAs is evident in Table 3, the zirconium-containing plaster layers 1 and 2 show in each case a degreehigher drying than the comparative plaster layers 1 and 2, without considering the binder (the synthetic resin-coating 1 and 2 layers contain different synthetic-resin dispersion binders) without considering the drying time.••