MXPA01008278A - Powder-slurry that can be hardened by actinic radiation or optionally by thermal means, method for producing said slurry and use of the same - Google Patents

Abstract

The invention relates to an intrinsically viscous powder-slurry that can be hardened by actinic radiation or optionally by thermal means, which contains solid spherical particles with an average particle size of 0.8 to 20&mgr;m and a maximum particle size of 30&mgr;m. The clear powder coating slurry contains 0.05 to 1 meq/g of ion-forming groups and 0.05 to 1 meq/g of neutralising agents and has a viscosity of (i) 50 to 1000 mPas at a shear rate of 1000 s-1, (ii) 150 to 8000 mPas at a shear rate of 10 s-1 and (iii) 180 to 12000 mPas at a shear rate of 1 s-1.

Description

POWDER PASTE THAT CAN HARDEN THROUGH ACTING RADIATION OR ALLOWING OPTION BY MEANS THERMAL METHOD TO PRODUCE SUCH PASTA AND USE OF THE SAME The present invention relates to a novel powder paste curable with actinic radiation and, if desired, thermally. The present invention also relates to a novel process for preparing this powder paste. The invention relates at least to the use of the novel powder paste for preparing transparent layer materials and also single layer and multiple layer transparent layer systems for the automotive sector and the industrial sector. The automotive chassis are now preferably coated using liquid coating materials, ie spray paint. These coating materials give rise to numerous environmental problems due to their solvent content. The same applies to the use of transparent layer materials transported by water, since they always contain certain quantities of organic solvents. Heat-curable water-borne transparent coat materials of this type are known from German patent DE-A-196 23 371. Directly after application, conventional water-borne transparent layer materials do not dry to a powder if not that they flow into the form of a continuous movie instead. They comprise aqueous secondary dispersions and are used in the automotive sector for aqueous multiple layer systems or one or two aqueous component clearcoat materials. The intention here is that the dispersions stable to sedimentation have an average particle size of about 10 to about 200 nm. The reason, known by the worker experienced in this technique, is that the better the stabilization and the smaller the size of the dispersion particles, the less their tendency to sedimentation. Reliable application behavior and a reduction in explosive sound tendency, requires the use of up to 20% by weight of solvents as well. For this reason, increasing efforts have been made in recent years to use powder coating materials for coating. The results to date, however, have not been satisfactory, due in particular to the need for increased film thicknesses in order to obtain a uniform appearance.

Additional problems of powder coating materials for thermal curing arise from the requirement of blocking resistance in storage and storage capacity even at warm temperatures. In order to ensure that this requirement is met, the softening point of the coating powders must be raised. Due to the high softening point of the coating materials, the thermally activated entanglement reaction starts as soon as the powder melts on the substrate takes place, before an optimum leveling of the film surface has been achieved. To solve this problem, German patents DE-A-24 36 186 and DE-A-26 47 700, European patents EP-AO 098 655, EP-AO 286 594, EP-AO 410 242, EP-A-522 648, EP-AO 585 742, EP-AO 636 669 and EPA-0 650 979, the international patent application WO 93/25596 and the United States of America patents US-A-4, 064,161, US-A- 4, 129,488, US-A-4, 163,810, US-A-4, 208, 3130 and US-A-5,639,560 propose ultraviolet curable powder coating materials in which it is possible to separate the melting operation from the interlacing. The ultraviolet powder coating materials described to date are all based on substances containing acrylic or vinyl unsaturation, which due to the high melting temperature required for an effective blocking resistance can also undergo thermal polymerization prior to ultraviolet irradiation. In order to guarantee blocking resistance, the binders used for the UV powder coating materials must be absolutely solvent-free polymers, which, however, are very problematic to obtain due to their tendency to undergo thermal polymerization. One problem with UV powder coating materials is that they are only suitable in limited form for coating three-dimensional objects since, with such objects, regions of shadow occur in which UV powder coating materials experience little or no cured. The same applies to UV powder coating materials comprising masking pigments. Attempts have been made to solve this problem by means of powder coating materials that are thermally curable and with actinic radiation. A dual curing powder coating material of this type is known from European patent EP-AO 844 286. It comprises an unsaturated binder and a second resin copolymerizable therewith, and also a photoinitiator and a thermal initiator, and therefore it is thermally curable and with actinic radiation. However, this double curing powder coating material is used as a pigmented top coating material, which is surface cured with ultraviolet light and thermally in the regions near the substrate. The aforementioned patent does not disclose whether this known powder coating material is also suitable for producing transparent layers in multiple layer systems. The general problem with the use of powder coating materials, that is, due to the different application technologies, is that they can not be used on existing installations designed for liquid coating materials, which are not combined with solvent by the coating material in double curing powder. This was the reason why the development of thermally curable powder coating materials is the form of aqueous dispersions that can be processed using liquid coating technologies. Such powder-coated clear dispersions, known to those of ordinary skill in the art also as powdered transparent powders or pastes, and their preparation and application are described in German patents DE 196 13 547, DE 196 17 086 , DE 196 18 657, DE 195 40 977 and DE 195 18 392, the European patent EP-AO 652 264, the international patent application WO 80/00447, and the patent of the United States of America US-A-4,268,542. Therefore, in the process known from US-A-4,268,542, a transparent powder coat based on acrylate resins is used which is suitable for automobile coating. In this case, a conventional powder coat is first applied to the entire chassis, after which the powder coating dispersion is applied as a clear coat material. Ionic thickeners are used in this clearcoat slurry, which leads to a relatively high sensitivity of the clearcoat film applied with respect to moisture, especially with respect to condensation. In addition, it is necessary to operate at high cooking temperatures of more than 160 ° C. The transparent powder coating paste known from European Patent EP-AO 652 264 is prepared by first coextruding the solid binder and the crosslinking components and any additives, as is normal with the production of powder coating materials, and then subjecting the coextruded to dry milling, after which they are converted into a transparent powder layer paste in a wet milling step using emulsifiers and wetting agents. Unlike powder coated clear materials, these known clear coat powders can be processed in conventional wet coating installations and can be applied substantially at a lower film thickness of approximately 40 μm against approximately 80 μm in the case of powder coating materials, with good leveling and with a chemical resistance comparable with that of the powder coating materials. However, conventional milling processes do not always ensure such a high degree of homogenization of the components as would be desirable at present, or said degree of homogenization must be achieved through multiple extrusion means, which is laborious. In conventional powder clearcoat pastes, relatively large particles are usually undesirable, as they tend to sedimentation. Furthermore, in the application and entanglement of transparent powdered layer pastes there is an increased tendency to form vertical vibration marks (blister-shaped cavities enclosed in the coating film). The situation with cracking known as desiccation cracking, in powdery powder films that have been initially dried at room temperature or at slightly elevated temperatures, although not cooked, is similar. Said cracks by drying do not flow completely to the cooking and in the baked film they form defects of visible flows in the form of grooves with leather texture, and these cracking by desiccation which are more pronounced and more frequent at a greater thickness of the dry film. In the case of automotive chassis electrostatic coating, relatively high film thicknesses can occur locally when there is a higher field linear density at sites where they are particularly exposed due to geometry. Such sites are susceptible to overcoating which are particularly susceptible to cracking by desiccation. The transparent powder coating paste known from German patent DE-A-196 17 086 has an average particle size of the solid particles from 0.1 to 10 μm. In this case, it is preferred to use average particle sizes from 0.23 to 0.43 μm. For the purposes of stabilization it is necessary, in addition to ionic stabilization, to use external emulsifiers as well as polyethylene oxide adducts, which reduce the resistance of the coating to water and moisture. In addition, those known transparent powder coating pastes still include certain amounts of organic co-solvents or leveling agents, which can not be removed since they are essential for the flow properties of the partially dried film. In addition, its preparation requires special equipment such as pressure release homogenizer nozzles. Before application, they are adjusted to the viscosity of application with the help of thickeners; a complex viscosity behavior however is not described. Furthermore, the patent does not teach how the problem of cracking by desiccation in transparent powdered layer pastes can be solved. However, the general problem of entanglement thermally activated to the evaporation of water and which essence of the resulting powder coating is not yet resolved with this technology, since the entanglement begins not at a precisely defined temperature but rather gradually , before the water has completely evaporated and an optimal surface has formed. The water that continues to emerge after the entanglement reaction that has started, due to the high temperatures required is a cause of the blisters and craters. It is an object of the present invention to provide a novel powdery transparent layer paste which does not have the disadvantages of the prior art. In particular, the novel clear powder coat stock should be capable of being prepared with a smaller number of processing steps than conventional clear powder coat stock; at the same time, however, due to its typical powder paste properties and its comparable particle sizes, it must have an application behavior whose advantages are similar to conventional pastes. Meeting the known water-borne transparent layer materials, the novel transparent powder coating pastes should ensure a more reliable application behavior with respect to vertical vibration at the required film thicknesses of approximately 40-50 μm even without the aid of organic solvents. In addition, novel transparent powder coating pastes must be curable with actinic radiation. In addition, they should open the possibility of combining the advantages of curing with actinic radiation with those of thermal curing, without having the specific disadvantages of the methods. It is another object of the present invention to find a novel process for preparing powdered pastes that continue to ensure the essential advantage of mixing the components in solution, ie a very good homogeneity of the resulting particles. Accordingly, the invention provides the novel pseudoplastic powdery paste curable with actinic radiation and, if desired, thermally, comprising solid spherical particles with an average size from 0.8 to 20 μm and a maximum size of 30 μm, and having a content of the ion formation group from 0.05 to 1 meq / g, a neutralizing agent content from 0.05 to 1 meq / g, and a viscosity of (i) from 50 to 1000 mPas at a shear rate of 1000s' 1, (ii) from 150 to 8000 mPas at a shear rate 10s'1, and (iii) from 180 to 12,000 mPas at a shear rate of 1s'1. In the following text, the novel pseudoplastic powder paste curable with actinic radiation and, if desired, thermally referred to for brevity purposes as the "paste of the invention. In addition, the invention provides the novel process for preparing a powder paste. pseudoplastic curable with actinic radiation and, if desired, thermally by 1. emulsification of organic solution comprising 1.1 curable components with actinic radiation, and if desired, 1.2 thermally curable components, to give an oil-in-water emulsion. 2. the removal of organic solvent or organic solvents, 3. partial or complete replacement of the volume of solvent removed by water, to give a powdery clear layer paste comprising solid spherical particles, wherein the powdery paste is further mixed with 4. at least one ionic thickener, especially anionic, and at least one non-ionic associative thickener. In the following text, the novel process for preparing a pseudoplastic powder paste curable with actinic radiation and, if desired, thermally referred to for brevity as the "process of the invention" The technical advantages of the paste of the The invention is based on its ability to be cured with actinic radiation, and it also has the ability to combine the known advantages of thermally curable transparent powder coat pastes, especially those of spray application, with those of materials of UV powder coating especially the separation of the interlacing melting process It has surprisingly been found that if the combined film has a low residual water content, the ultraviolet curing is particularly rapid and complete.The natural balance between the content of water from the film and the surrounding air, which depends on the hydrophilicity of the pi interlacing nturas, is established quickly even when the system is cooling. Most surprisingly, the paste of the invention is stable even without external emulsifiers and organic solvents. The paste of the invention is curable with actinic radiation. In the context of the present invention, actinic radiation represents electron beams or ultraviolet radiation, especially ultraviolet radiation. For the paste of the invention it is essential that the average size of the solid particles be from 0.8 to 20 μm, particularly preferably from 1 to 15 μm, and in particular from 2 to 10 μm. By mean particle size it is implied that the average value of 50% as determined by the laser diffraction method, ie 50% of the particles have a diameter D of the mean and 50% of the particles have a diameter D of the average. Pastes having said average particle sizes exhibit better application behavior and, in the applied film thickness of > 30 μm, as is currently practiced in the automotive industry for automotive finishing, exhibits a very reduced tendency towards vertical vibration marks and toward cracking by desiccation than conventional clear powder pastes. The particle size reaches its upper limit when the particles due to their size are no longer able to flow completely to the cooking, as a result of which the release of film is adversely affected. When appearance requirements are not great, however, they can also be superior. An upper limit of 30 μm is considered sensitive, since blocking of the spray nozzles of the high sensitivity application device can be expected on this particle size. The paste of the invention can be substantially free of organic solvents. In the context of the present invention this means that it may have volatile solvent content of < 1% by weight, preferably from < 0.5% by weight and with particular preference < 0.2% by weight. It is of a very particular advantage in this context for the residual content that is lower than the analytical detection limit, especially below the detection limit of gas chromatography. Similarly, the paste of the invention can be substantially free, in the above-mentioned sense, from external emulsifiers. The particle sizes described above for use according to the invention can therefore be obtained even without the assistance of additional external emulsifiers. According to the invention, the components curable with actinic radiation and also, if appropriate, the thermally curable components have a general ion group content corresponding to an average acid number or amine content number of 3 to 56 g KOH / g solids (MEQ acid or MEQ amine from 0.05 to 1.0 meq / g solids), preferably up to 28 (MEQ acid or MEQ amine: 0.5) and in particular up to 17 (MEQ acid or MEQ amine: 0.3). According to the invention, it is advantageous if the ion formation groups are in the binders. It is of a very particular advantage according to the invention in this context if those groups are present in the thermally curable binders, when the powdered pastes of the subject invention are curable with actinic radiation and in thermal form. According to the invention, the target level of such groups is generally low, since free groups of this type can remain in the curable coating material and can reduce their resistance to environmental substances without the chemical agents. On the other hand, the level of such groups must be sufficient to ensure the desired stabilization. The use of neutralization agents, the ion formation groups are 100% or only the <; 100% (partially) neutralized. The amount of the neutralizing agent is selected such that the MEQ value of the paste of the invention is below 1, preferably below 0.5, and in particular below 0.3 meq / g solids. It is of advantage according to the invention if the amount of neutralizing agent corresponds to at least one MEQ value of 0.05 meq / g solids. The chemical nature of the curable binders with actinic radiation and also the thermally curable binders, when used, is generally not restrictive, provided that they contain ion-forming groups that are convertible into salt groups by neutralization and therefore both are able to take care of the ionic stabilization of the particles in water. Suitable anion-forming groups include acidic groups such as carboxylic acid, sulfonic acid, and phosphonic acid groups. Accordingly, the neutralization agents used with reward in bases, such as alkali metal hydroxide, ammonia or amines. The alkali metal hydroxides can only be used to a limited extent, since during cooking the alkali metal ions are not volatile and, due to their incompatibility with organic substances, can darken the film and cause loss of gloss. Consequently, ammonia or amines are preferred. In the case of amines, water-soluble tertiary amines are preferred. By way of example, mention is made of N, N-dimethylethanolamine or aminoethylpropanolamine (AMP). Suitable cation formation groups include amines, primary, secondary or tertiary. Accordingly, the neutralization agents used comprise, in particular, organic acids of low molecular mass such as formic acid, acetic acid or lactic acid. Binders containing cation forming groups are known from the field of electrodeposition coating materials. By way of example, reference is made to EP-A-0 012 463, EP-A-0 612 818, and US-A-4,071,428. For the preferred use of the inventive pulp patent in automotive topcoat as non-pigmented clearcoat materials, polymers or oligomers containing acid groups as ion-forming groups are preferred, since these anionic binders are generally more resistant to yellowing than the class of cationic binder. However, cationic binders containing groups convertible to cations, such as amino groups, can be used in principle in the same way, provided that the field of use tolerates their typical secondary properties such as the tendency to yellow. Since binders containing anion formation groups are possible for the use of any desired resins containing the aforementioned acid groups. However, it is essential that they additionally carry additional groups that ensure the interlacing capacity. In the case of binders curable with actinic radiation, preference is given according to the invention to the groups Ethnically unsaturated. In the case of thermally curable binders that can also be used, hydroxyl groups are of advantage. Suitable oligomers and polymers of this type used in accordance with the invention preferably include poly (meth) acrylates preferably linear and / or branched and / or block, combined and / or random, polyesters, alkyds, polyurethanes, acrylated polyurethanes, polyesters acrylates, polylactones, polycarbonates, polyethers, (meth) acrylates, or polyureas. In addition to the ethylenically unsaturated groups and also, if desired, the hydroxyl groups, the oligomers and polymers may contain other functional groups as well, such as ether, amide, Measure and / or thio groups, provided they do not disturb interlacing reactions.

These oligomers and polymers are known to skilled workers and a number of suitable compounds are available in the market. According to the invention, the paste of the invention comprises components that are curable with actinic radiation, especially ultraviolet radiation. Suitable binders are all those radiation curable, low molecular mass, oligomeric and / or polymeric compounds, preferably radiation curable binders, which are known from the UV coating field especially those based on ethylenically unsaturated prepolymers and / or oligomers ethylenically unsaturated, reactive diluents if desired, and also one or more photoinitiators if desired. Examples of suitable radiation curable binders are copolymers of (meth) acrylic (meth) acryloyl-functional, polyether acrylates, polyester acrylates, unsaturated polyesters, epoxy acrylates, urethane acrylics, amino acrylates, melamine acrylates, silicone acrylates. and the corresponding methacrylates. Binders that are free of aromatic structural units are preferred for use. It is important that they do not reduce the vitreous transition temperature Tg of the particles of the paste of the invention to such an extent that there is a risk of concretion. The particular suitability is characteristic of acrylate resins containing dependent functional groups, such as epoxide groups or hydroxyl groups, for example, which contain molecular weights on the scale from Mn 1000 to 10000 with molecular weight distributions < 4, as described for example, in DE-A-42 03 278, which are subsequently reacted with acrylic acid or acrylic acid derivatives, such as acryloyl chloride, to give the corresponding acrylated acrylates (EP-AO 650979). Epoxy functional precursors suitable for acrylated acrylates curable with actinic radiation are, for example, polyacrylate resins containing epoxide groups, which can be prepared by copolymerization of at least one ethylenically unsaturated monomer which contains at least one group epoxide in the molecule at least one additional ethylenically unsaturated monomer containing no epoxide group in the molecule, at least one of the monomers which is an ester of acrylic acid or methacrylic acid. Polyacrylate resins of this type, which contain epoxide groups, are known, for example, from EP-A-299 420, DE-B-22 14 650, DE-B-27 49 576, US-A 4,091,048 and US-A-3,871, 379. Examples of ethylenically unsaturated monomers which do not contain an epoxide group in the molecule are alkyl esters of acrylic and methacrylic acid containing from 1 to 20 carbon atoms in the alkyl radical, especially methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate and 2-ethylhexyl methacrylate. Additional examples of ethylenically unsaturated monomers that do not contain epoxide groups in the molecule are the acid amides, such as acrylamide and methacrylamide for example, maleamide, vinylaromatic compounds such as styrene, methylstyrene and vinyltoluene, nitriles, such as acrylonitrile and methacrylonitrile, vinyl and vinylidene halides, such as vinyl chloride and vinylidene fluoride, vinyl esters, such such as vinyl acetate, for example, and hydroxyl-containing monomers, such as, hydroxyethyl, acrylate and hydroxyethyl methacrylate, for example. The functional epoxy monomers used in the epoxy-functional binders are preferably glycidyl acrylate, glycidyl methacrylate, allyl esters and allyl glycidyl ether. The epoxy-containing polyacrylate resin usually has an epoxide equivalent weight from 400 to 2500, preferably from 420 to 700, a numerical average molecular weight (determined by gel permeation chromatography using a polystyrene standard) from 2000 to 20 000, preferably from 1000 to 10000, and a glass transition temperature Tg from 20 to 100, preferably from 30 to 90, with particular preference from 40 to 80 and especially from 50 to 70 ° C (measured through differential scanning calorimetry (DSC )). The particular preference is given for approximately 50 ° C. The polydispersity of the molecular weight distribution is preferably below 6, particularly preferably below 3. Examples of suitable acrylate resins are those described in DE-A-42 03 278. Mixtures of two or more acrylate resins can also be used. In the epoxy-containing polyacrylate resin it can be prepared by addition polymerization according to methods that are well known. In addition, the functional resins may also contain aromatic compounds. Its proportion must be below 60%, preferably below 50%. These compounds can, for example, comprise vinylaromatic compounds. An example of these is styrene. It is also possible to use the following: - Unsaturated polymers of a wide variety of types, containing from 0.5 to 3.5 double bonds for a molecular weight 1000 daltons, which are obtained by polymer reaction of the polymer with unsaturated substances (DE- A-24 36 186). - Polymethacrylate having a low molecular weight from 500 to 25,000 daltons and a narrow distribution, obtained by anionic polymerization and functionalized by reaction of polymer analogue with double bonds (US-A-4,064,161). - The combinations of solid epoxy acrylates, as can be obtained by reaction of diepoxy resins with acrylic acid and partially crystalline solid polyester acrylates as can be obtained from carboxyl-terminated polyester by reaction with glycidyl acrylates (US-A-4) , 129.488). - Unsaturated polyurethane acrylates with a melting range from 50 to 180 ° C (EP-A-O 410242). - Combinations of unsaturated polyurethane acrylates with unsaturated crystalline polyesters, to improve the blocking resistance (EP-A-0 585742). - Combinations of unsaturated polyesters or polyacrylates with polyrurethane vinyl ethers (EP-A-0 636669). - Functional polyacrylates of olefinically unsaturated monomers, by reaction of the functionally complementary polyacrylates (EP-A-0 650978). An embodiment of EP-A-0 650 978, the base polymers are prepared in a high temperature polymerization. - The free double-cross polyacrylates, which can be entangled by means of hydrogen transfer to photochemically excited copolymer photoinitiators of the Norrish II type (DE-A-44 13436).

Polyacrylates free of double bonds and containing dihydrodicyclopentadienol acrylate, which can be entangled by means of hydrogen transfer to photochemically excited copolymer photoinitiators of the Norrish II type (DE-A-eM9600 147).

Suitable examples of components curable with actinic radiation are described in the international patent applications - PCT / EP 96/05769: entangled polimeric compounds containing at least one ethylenic double bond, in a mixture with organic compounds containing by at least one hydrogen atom having a maximum binding energy of 397 kg / mol; or - PCT / EP97 / 07074: radiation-crosslinkable acrylic polymers which can be prepared by reaction of polyacrylate polymer analogue with substances which introduce a group that forms free radicals with active radiation. The paste of the invention comprises at least one of the aforementioned components. The photoinitiators required for UV entanglement are generally already present in the binders described above and are generally selected from the compounds known from the prior art. In particular, the photoinitiators of the Norrish I I type are used. Photoinitiators of this type are common and known. Its mechanism of action is based on an intramolecular variant of hydrogen abstraction reactions, as they occur in different ways in the case of photochemical reactions. By way of example, reference is here made to Rummp Chemie Lexikon, 9a, enlarged and revised edition, Georg Thieme Verlag, Stuttgart, Vol. 4, 1991. An example of a suitable photoinitiator of this type is 4-hydroxybenzophenone. According to DE-A-44 13 46 and DE-A-196 00 147, Polymers are UV curable without added photoinitiators. Particularly well-interlaced films are obtained using mixtures of inert polymers and polymers in accordance with DE-A-44 13 436 and DE-A-196 00 147 with a particularly high fraction of photo-initiators of photochemically excitable copolymers of the Norrish II type . According to the invention, it is an advantage if the components described above are present predominantly or exclusively in the solid particles. In the case of the thermally curable binders that can be used, polyacrylates, polyesters, alkyd resins, polyurethanes and acrylated polyurethanes are advantageous according to the invention and are therefore preferably used. Examples of suitable thermally curable polyacrylates are described in the European patent application EP-A-0 767 185 and in US-A-5,480,493, 5,475,073 and US Pat. ,534,598. additional particularly preferred polyacrylate examples are sold under the tradename Joncryl®, such as, for example, Joncryl® SCX 912 and 922.5. The preparation of these polyacrylates is a common knowledge and is described, for example, in the work Houben-Weyl, Methoden der organischen Chemie, 4th edition, volume 14/1 pages 24 to 255, 1961. The preparation of thermally alkyd resin polyesters Curable materials which are preferably used are also of common knowledge and are described, for example, in the work Ullmans Encykiopádie der technishen Chemie, 3a. edition, volume 14, Urban & Schwarzenberg, Munich, Berlin, 1963, pages 80 to 89 and pages 99 to 105, and also in the following books: "Resines Alkydes-Polyesters" by J. Bourry, Dunod, Paris, 1952, "Alkyd Resins" by C.R. Martenes, Reinhold Publishing Corporation, New York, 1961, and also "Alkyd Resin Technology" by T.C. Patton, Interscience Publishers, 1962. Polyurethanes and / or thermally curable acrylated polyurethanes whose use is particularly preferable are described, for example, in EP-AO 708 788, DE-A-44 01 544, DE-A-195 34 361, EP-AO 089 497, EP-AO 256 540, EP-AO 260 447, EP-AO 297 576, WO 96/12747, EP-AO 523 610, EP-AO 228 003, EP-AO 397 806, EP-AO 574 417, EP-AO 531 510, EP-AO 581 211, EP-AO 708 788, EP- AO 593 454, DE-A-43 28 092, EP-AO 299 148, EP-AO 394 737, EP-AO 590 484, EP-AO 234 362, EP-AO 234 361, EP-AO 543 817, WO 95 / 14721, EP-AO 521 928, EP-AO 522 420, EP-AO 522 419, EP-AO 649 865, E-PA-0 536 712, EP-AO 596 460, EP-AO 596 461, EP-AO 584 818, EP-AO 669 356, EP-AO 634 431, EP-AO 678 5366, EP-AO 354 261, EP-AO 424 705, WO 97/49745 and EP-AO 401 565. The interlacing agents suitable for Thermal curing are all the interlacing agents that are common in the field of final light-stable paint coat materials. Examples thereof are etherified melamine and formaldehyde resins, benzoguanamine resins, compounds or resins containing anhydrous groups or compounds or resins containing epoxide groups, blocked and / or unblocked polyisocyanates, beta-hydroxy-alkylamides such as N, N, N7N'-tetrakis (2-hydroxyethyl) -adipamide or N, N, N \ N'-tetrakis (2-hydroxypropyl) -adipamide, with compounds containing on average at least 2 groups capable of transesterification, examples being products of reaction of malonic diester and polysisocyanates or of esters and partial esters of polyhydric alcohols of malonic acid with monoisocyanates, as described [lacuna] in European patent EP-AO 596 460, and / or tris (alkoxycarbonylamino) -triazines, as described in US-A-4,939,213, US-A-5,084,541, US-A-5,288,865 and EP-AO 604922. Of these, the blocked polyisocyanates are advantageous and therefore are used with particular preference. Examples of suitable blocked polyisocyanates are described in German patents DE-A-196 17 086 and 196 13 269, in European patents EP-AO 004 571 and 0 582 051, and in the patent of the United States of America US- A-4,444,954. The paste of the invention comprises ionic and nonionic thickeners. This represents the tendency of comparatively large solid particles towards sedimentation that is effectively counteracted. Examples of nonionic thickeners are hydroxyethylcellulose and polyvinyl alcohols. Non-ionic associative thickeners are also available in the market in a wide selection. These generally consist of water-dilutable polyurethanes which are reaction products of water-soluble polyetherdiols, aliphatic diisocyanates and monofunctional hydroxyl compounds with an oraganophilic radical. A particularly preferred embodiment refers to non-ionic associative thickeners which are capable of photochemically reacting with themselves and / or with the other components curable with actinic radiation, thereby achieving a further improvement in the coating properties. The non-ionic associative thickeners curable with actinic radiation can be obtained by incorporating double bonds or groups containing easily-extracted hydrogen atoms, such as dicyclopentadienyl groups and / or photoinitiator groups of the Norrish II type, especially of benzophenone groups. Ionic thickeners are also commercially available. These thickeners normally contain anionic groups and are based in particular on specific polyacrylate resins with acid groups, some or all of which may have been neutralized. Examples of suitable thickeners for inventive use are known from the textbook "Lackadditive by Johan Bielemann, Wiley-VCH, Weinheim, New York, 1998", pages 31 to 65. and therefore no further description is needed. For the dough of the invention it is essential that both types of thickener described above are present therein. It is advantageous according to the invention in this case if the thickeners are present predominantly or exclusively in the aqueous phase. The amount of thickeners that will be added, and the ratio of ionic thickener to non-ionic thickener, is determined by the desired viscosity of the paste of the invention, which in turn is predetermined by the stability to the required sedimentation and the specific demands of spray application. Therefore the experienced worker is able to determine the amount of thickeners and the ratio of the types of thickener to one another based on simple considerations, possibly with the help of preliminary tests. According to the invention, the established viscosity range is from 50 to 1500 mPas at a shear rate of 1000 s'1 and from 150 to 8000 mPas at a shear rate of 10 s'1 and also from 180 to 12 000 mPas at a shear rate of 1s "1. This viscosity behavior, known as "pseudoplasticity" describes a state that does not justify the spray application requirements, on the one hand, and the requirements in terms of storage stability and sedimentation stability on the other: in the state of motion, such as when the pulp is pumped of the invention in circulation in the ring circuit of the coating plant and when sprayed, for example, the paste of the invention adopts a low viscosity state which ensures a simple processing capacity. Without intentions of shearing, on the other hand, the viscosity rises and therefore ensures that the coating material already present in the substrate to be coated has a reduced tendency to form displacements on the vertical surfaces. In the same way, a result of the higher viscosity in the steady state, such as during storage, for example, is that the sedimentation of the solid particles is largely prevented, or that any slight degree of sedimentation of the powder of the invention during the storage period can be removed again by stirring. In addition to the essential components described above, the solid particles of the paste of the invention may include additives as are commonly used in clearcoat materials. In this context it is essential that these additives do not substantially reduce the glass transition temperature Tg of the binders. Examples of suitable additives are crosslinking catalysts, emulsifiers, defoamers, adhesion promoters, additives to improve substrate wetting, additives to improve the surface uniformity, opacifying agents, nanoparticles, light stabilizers, corrosion inhibitors, biocides, Flame retardants or polymerization inhibitors, as described in detail in the book "Lackadditive" [Additives for coatings] by Johan Bielemann, Wiley-VCH, Weinheim, New York, 1998. Thermally curable reactive diluents, curable reactive diluents with Actinic radiation or flow improvers that can be incorporated by entanglement in the film can be added to the paste of the invention. However, it is important that these components are preferably located in the external aqueous phase of the paste of the invention and not in the dispersed organic phase, where they would reduce the glass transition temperature Tg and therefore would cause the concretion or coagulation of any particles. sedimented. Examples of suitable compounds of this type are oligomeric polyols which can be obtained by hydroformylation and subsequent hydrogenation from oligomeric intermediates obtained by cythesis monoolefin and acyl monoolefin reactions; examples of suitable cyclic monoolefins are cyclobutene, cyclopentene, cyclohexene, cyclohexen, cycloheptene, norbornene or 7-oxanorbornene: examples of suitable acyclic monoolefins are present in the hydrocarbon mixtures obtained in petroleum processing by pyrois is catalytic (cut C5); examples of oligomeric polyols suitable for use according to the invention have a hydroxyl number (OHN) from 200 to 450, a number average molecular weight Mn from 400 to 1000, and a mass average molecular weight Mw of 600 to 1100; Further examples of suitable compounds of this type are branched, cyclic and / or acyclic C9-C16 alkanes functionalized with at least two hydroxyl groups, especially diethyl octanediols and also cyclohexanedimethanol, neopentyl glycol hydroxypivalate, neopentyl glycol, timethylolpropane or pentaerythritol. Reactive curable diluents with suitable radiation include polyfunctional ethylenically unsaturated compounds of low molecular mass, examples of suitable compounds of this type are esters of acrylic acid with polyols, such as neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate or tetraacrylate pentaerythritol; or reaction products of hydroxyalkyl acrylates with polyisocyanates, especially with aliphatic polyisocyanates. The reactive diluents may be present in the aqueous phase and / or in the solid particles of the paste of the invention. When the paste of the invention is thermally curable and with actinic radiation, the ratio of thermally crosslinkable components to the interlaxable components with actinic radiation can vary widely. It is guided mainly by the fact if the paste of the invention is intended to be curable mainly in thermal or mainly actinic radiation form and also by the intended use of the paste of the invention. For example, a paste of the invention that is curable primarily with actinic radiation will be prepared if the intention is to coat substrates whose ability to withstand thermal stress is low. In general, the ratio of curable components with actinic radiation to the thermally curable components can be from 20: 1 to 1:20, preferably from 10: 1 to 1:10, particularly preferably from 5: 1 to 1: 5 and particularly from 3: 1 to 1: 3. In each individual case, therefore, the experienced worker is able to determine the appropriate relationship based on their knowledge in the art, possibly with the help of simple preliminary tests. By itself, the paste of the invention can be prepared in any desired manner. According to the invention, it is advantageous to prepare it by means of the process thereof. In the process of the invention, the ionically stabilizing binders and the entangling agents and likewise, when appropriate, the reactive additives and diluents are mixed in organic solution and together with the aid of neutralizing agents are dispersed in water by the technique of secondary dispersion. First, a water-in-oil emulsion is formed, which with the additional dilution changes to an oil-in-water emulsion. This point is generally reached at solids contents of < 50%, by weight based on the emulsion, and is evident externally from a very marked reduction in viscosity during the course of dilution. The emulsion thus obtained, which still contains solvent, is subsequently released from the solvents by means of azeotropic distillation. The distillation temperature is guided mainly by the glass transition temperature Tg of the binders. In order to avoid clots, ie, a flow together of the particles which according to the invention have only a low level of stabilization, until almost separating the continuous organic phase, during the distillation, it is essential to keep the distillation temperature below of the vitreous transition temperature Tg. As a substitution, the vitreous transition temperature can also be described by means of the minimum film formation temperature of the dispersion. The minimum film formation temperature can be determined by extracting the dispersion on a glass plate using a coating rod and heating the extraction in a gradient oven. The temperature at which the pulverulent layer forms a film is referred to as the minimum film-forming temperature. According to the invention, it is advantageous if the minimum film-forming temperature is more than 20 ° C, in particular more than 30 ° C. According to the invention, it is advantageous if the solvents that are removed are distilled at a distillation temperature below 70 ° C, preferably below 50 ° C, and in particular below 40 ° C. If desired, the distillation pressure in this case is selected so that the temperature range is maintained in the case of solvents with a relatively high boiling point. In its simplest form, azeotropic distillation can be carried out by stirring the emulsion in an open container at room temperature for several days. In the preferred case, the emulsion containing the solvent is released from the solvents in a vacuum distillation. In order to avoid high viscosities, the amount of water and solvents removed by evaporation or distillation are replaced by water. Water can be added before, during or also after evaporation or distillation by addition in portions. After the loss of the solvents, the vitreous transition temperature of the dispersed particles rises, and instead of the emulsion containing the previous solvent (liquid dispersion in liquid), a dispersion of solid in liquid forms, the paste of the invention. The paste of the invention advantageously has a solids content of 10 to 60% by weight, in particular of 20 to 50% by weight. To produce the transparent layers of the invention, the paste of the invention is applied to the substrate to be coated. No special measures need to be taken here; instead, the application can take place according to the usual and known techniques, for example, according to the wet-on-wet technique which is used in the finish, automotive OEM, which is a particular additional benefit of the paste of the invention.

Even another particular advantage of the dough of the invention lies in the fact that it is suitable for producing not only transparent layers of individual cover but also a multiple cover transparent layer system. In order to produce these multiple cover transparent layer systems, it can be combined with all common and known transparent layer materials. The multiple cover transparent layer systems in question exhibit a very good inter-layer adhesion. After application of the layer of the invention dry without problems and does not show film formation at the processing temperature, generally at room temperature. In other words, the paste of the invention applied as a wet film releases water at room temperature or at a slightly elevated temperature without the particles present in it changing their original solid form. The powdery solid film allows the waste water to evaporate more easily than a wet film does. Consequently, the risk of evaporated water ampoules ("vertical vibration marks") enclosed in the cured film is reduced. In addition, the tendency to cracking of desiccation is extremely reduced. A surprising finding here is that, at larger particle sizes of the pulps of the invention, their tendency to cracking on drying is less. In the subsequent curing step, the substantially water-free powder layer melts and is induced to entangle. In many cases, it may be advantageous to offset the flow process of the entanglement reaction in terms of time, by the operation of a step heating program or a heating ramp. The molten layer is then cured by exposure to actinic radiation, especially ultraviolet light. The curing of radiation can be followed by a thermal curing in which those regions of the transparent layer film near the substrate and / or, in the case of three-dimensional objects, the shadow regions, can be completely cured, especially in thermal form. In general, thermal curing is conducted at temperatures between 120 and 160 ° C. The corresponding cooking time is between 1 and 60 minutes. In this case the particular advantage of the paste of the invention is evident, that is to say that by means of the ratio of thermally curable components to the components curable with actinic radiation it can be adapted in a simple and precise way to the thermal load bearing capacity and / or the three-dimensional shape of the substrate to be coated. For example, in the case of a three-dimensional object having large areas of shadow, the focus can be placed on the thermal curing and the radiation curing can be used only for a first partial entanglement. If, on the other hand, the substrate is a flat substrate whose thermal load bearing capacity is low, radiation curing will be used principally. Between these two extremes, each graduation is conceivable and also achievable. The resulting transparent or single cover or multiple cover layer has extraordinary performance properties. Therefore, the transparent layer of the invention adheres firmly to all common and known base covers or to primed or unprimed substrates such as metal, glass, wood or plastic. It is high gloss, uniform, resistant to cracking, weather resistant and free of defects. Furthermore, due to its advantageous properties profile, it is also suitable for applications outside the automotive finish, particularly for furniture coating and for industrial coating, including coil coating and container coating.

Examples Preparation Example 1 1. Preparation of the polyacrylate resin solution A. 1291. 5 parts of methyl ethyl ketone (MEK) and 43.0 parts of mercaptoethanol were charged to a vessel and heated to 80 ° C.

By means of two separate feeding vessels, the initiator, which consists of 143.5 parts of TBPEH (tert-butyl pereethylhexanoate) and 86.1 parts of MEK, and the monomer mixture, which consists of 470.7 parts of terbutyl acrylate, 254.0 parts of n-butyl methacrylate, 287 parts of cyclohexyl methacrylate, 409.0 parts of hydroxypropyl methacrylate and 14.3 parts of acrylic acid were metered in the initial charge over the course of 5 hours at 80 ° C. Subsequently the bath was heated to 85 ° C and a portion of the volatile components was dissolved under reduced pressure at 800 to 500 mbar in the course of 5 hours. The batch was allowed to cool to about 60 ° C and the resin solution was discharged. The resin solution had the following characteristics: Solids: 69.8% (1 h at 130 ° C) acid number 27 mg solid resin KOH / g Preparation example 2 The preparation of a blocked polyisocyanate interlayer 837 parts of isophorone diisocyanate was charged into an appropriate reaction vessel and mixed with 0.1 part of dibutyltin dilaurate. Then a solution of 168 parts of trimethylolpropane and 431 parts of methyl ethyl ketone were slowly poured. As a result of the exothermic reaction, the temperature was increased. After that it had reached 80 ° C. the temperature was kept constant by external cooling and the rate of addition was slightly reduced if required. After termination of the feed, that temperature was maintained for about 1 hour until the isocyanate content of the solids had reached 15.7% (based on the NCO groups). The reaction mixture was then cooled to 40 ° C and a solution of 362 parts of 3,5-dimethyl thiol in 155 parts of methyl ethyl ketone was added over the course of 30 minutes. After the reaction mixture had been heated to 80 ° C due to the exothermic reaction, the temperature was kept constant for 30 minutes until the NCO content had dropped to less than 0.1%. Then 40 parts of n-butanol were added to the reaction mixture, its temperature was maintained at 80 ° C for an additional 30 minutes and after a brief cooling it was discharged. The reaction product had a solids content of 69.3% (one hour at 130 ° C).

Preparation Example 3 Preparation of a curable entanglement agent with actinic radiation. 1350 parts of Vestanat® T 1890 (trimerized isophorone diisocyanate, Creanova, formerly Chemische Werke Hüls) was charged to a vessel together with 907.2 parts of methyl ethyl ketone and 0.22 parts of dibutyltin dilaurate and 4.4 parts of hydroquinone were added. Then 864 parts of 4-hydroxybutyl acrylate were added slowly. As a result of the exothermic reaction, the temperature was increased. After the temperature had reached 60 ° C, it was kept constant by external cooling and the rate of addition was reduced slightly if necessary. After the completion of the feed, the reaction mixture was held at this temperature for about 2 more hours until the isocyanate content of the solids had dropped to less than 0.1%. Then 37 parts of n-butanol were added, the temperature was maintained at 60 ° C for an additional 30 minutes and the reaction product, after a brief cooling was discharged. The reaction product had a solids content of 69.5% (one hour at 130 ° C and a viscosity of 5.9 dPas (original viscosity, cone and plate viscometer at 23 ° C).

Example 1 The preparation of the transparent powder coating paste of the invention 1 375.7 parts of the acrylate resin solution A from the preparation example 1, 270.2 parts of the crosslinking solution from the preparation example 2 and 636.4 parts of the Interlacing agent from preparation example 3, curable with actinic radiation, were mixed in an open stirring vessel, with stirring, at room temperature for 15 minutes. Then 9.0 parts of Cyagard® 1164 L (Cytec ultraviolet absorber), 9.4 parts of liquid Tinuvin® 123 (sterically hindered amine HALS of Ceiba Geigy), 6.7 parts of N, N-dimethylethanolamine, 6.7 parts of dibutyltin dilaurate (DBTL) were added. ) and 120.0 parts of Darocure® (photoinitiator from Ciba Specíalty Chemicals) and 30.0 parts of Irgacure® (photoinitiator from Ciba Specialty Chemicals), and the mixture was stirred at room temperature for an additional 2 hours. It was then diluted with 528.8 parts of fully deionized water in small portions. After a 15-minute waiting period, 650.0 additional parts of DI water were added. A low viscosity aqueous emulsion with a theoretical solids content of 37% was formed which was stirred at room temperature for an additional 50 hours. The amount of liquid evolved by evaporation was replaced to the original level by the addition of DI water. This gave a powdery transparent layer (paste) suspension having the following characteristics: Solids (2 h 80 ° C): 36.2% MEQ acid: 0.05 meg / g solids MEQ base: 0.08 meg / g solids Solvent content: <; 0.05% (by gas chromatography) Particle size: 6.4 μm (D.50, Malvern laser diffraction measuring instrument).

In order to fix the appropriate viscosity profile, 56.5 parts of Acrysol® RM-8W (non-ionic associative thickener rohm &Haas solvent) and 16.2 parts of Viskalex® (anionic thickener based on polyacrylate resin, Allied Colloids) was stirred in 2500 parts of the aforementioned paste. The transparent layer paste has the following viscosity profile: 1020 mPas at a shear rate of 10 s'1 670 mPas at a shear rate of 100 s "1 255 mPas at a shear rate of 1000 s" 1 Transparent layer paste has a minimum film build-up temperature of 48 ° C. After two weeks of storage at room temperature, a slight sediment was formed, which was homogeneously reagized again for 5 minutes using a laboratory stirrer.

Example 2 The use of the transparent layer paste of the invention 1 from the example to produce multiple coating paint systems For the application of the clear powder layer paste of the invention 1 from the example 1, a integrated system, which is described below for the metallic "meteor gray" tone. Using a cup-type gun, a functional coating (Ecoprime® Meteorgrau [meteor gray], BASF Coatings AG) was applied to catholic-coated steel panels with commercially available electrocoating material. After flash-off at room temperature for 5 minutes, a meteorological gray metallic water-based coating material (Ecostar® Meterog rau, BAS F Coatings AG) was applied in the same manner to this coating and subsequently predried at 80 ° C. for 10 minutes . After the panels had cooled, the transparent powder coating paste 1 was applied in the same manner. Subsequently, instantaneous vaporization was applied to the panels for 5 minutes and then they were predried at 80 ° C for 10 minutes. After pre-drying, the clear powder coating paste of the invention 1 was radiation-cured first in a UV tunnel (1200 mJ, Aktiprint M ini 12-1 of Technigraph GmbH, 61279 Graevenwiesbach) and then baked in an oven. forced air at 145 ° C for 30 minutes. The coating system of the invention had an extraordinary appearance and a high level of resistance in the chemical test. No defects were seen in the form of vertical vibration marks or desiccation cracking in the applied transparent layer thicknesses. The surface of the transparent layer was extremely uniform. The following table gives a review of the tests conducted and the results obtained in them.

Table: Performance properties of the transparent layer paste the powder of the invention Properties Example Thickness of transparent layer 40-45 μm Glass at 20 ° C) 85 Micro-penetration hardness b) 185 BART acid test Chemical agents: 40 ° C 0 50 ° C 0.5 60 ° C 1 70 ° C 7 Etching by etching: 40 ° C 0 50 ° C 0 60 ° C 0 70 ° C 1 a) Byk brightness meter b) Fischerscope H100V (Vickers diamond pyramid) c) BART (BASF ACID RESISTANCE TEST) was used to determine the resistance of the film surface to acids and alkalis (= to chemical agents) and water droplets (= to etching by chemical attack). After cooking, the coating was exposed to additional temperature loads in a gradient oven (30 minutes at 40 ° C, 50 ° C, 60 ° C and 70 ° C). Previously test substances were applied (15% sulfuric acid, 10%, 35%, 6% sulfuric acid, 10% hydrochloric acid and 5% sodium hydroxide solution (chemical agents) and also completely deionized water (etching by chemical attack), 1, 2, 3, or 4 drops) in a defined manner using a volumetric pipette. After exposure to the test substances, they were removed under running water and the damage was determined visually after 24 hours according to a defined scale: Classification Appearance 0 no defect 1 light marking 2 marked / killed brightness / no uniformity marked / killed color / color change / a formation cracks / incipient through etching by etching transparent cover removed Each individual mark (point) was evaluated and the result was recorded as a sum of the classifications for the chemical agents and for the etching by chemical attack, in each case for a temperature.

Claims (10)

1. A pseudoplastic powdered paste curable with actinic radiation and, if desired, thermally, comprising solid spherical particles with an average size from 0.8 to 20 μm and a maximum size of 30 μm, and having a content of formation group of. from 0.05 to 1 meg / g, a neutralizing agent content from 0.05 to 1 meg / g, and a viscosity of (i) from 50 to 1000 mPas at a shear rate 1000 s "1, (ii) from 150 to 8000 mPas at a shear rate of 10 s "1, e (iii) from 180 to 12,000 mPas at a shear rate of 1 s" 1-

2. The powdery pasta according to claim 1, which has a solids content of 10 to 60% by weight, in particular from 20 to 50% by weight.

3. The powdery paste according to claim 1 or 2, characterized in that the average size of the solid spherical particles is from 1 to 15 μm and in particular from 2 to 10 μM. The powdery paste according to one of claims 1 to 3, comprising ionic thickeners and associative nonionic thickeners optionally crosslinkable with actinic radiation. The powdery paste according to one of claims 1 to 4, characterized in that the solid spherical particles comprise polyacrylates, polyesters, alkyd and / or polyurethane resins as thermally curable binders and methacryloyl-functional methacrylic copolymers, polyether acrylates, polyester acrylates, unsaturated polyesters, epoxy acrylates, urethane acrylates, amino acrylates, melamine acrylates and / or silicone acrylates and / or the corresponding methacrylates as the binders curable with actinic radiation. 6. The powdery paste according to claim 5, comprising photoinitiators and, if desired, crosslinking agents for thermal curing. The powdery paste according to one of claims 1 to 6, which has a minimum film-forming temperature of more than 20 ° C, in particular of more than 30 ° C. 8. The powdery paste according to one of claims 1 to 6, which is substantially free of organic solvents and external emulsifiers. 9. A process for preparing a pseudoplastic powder paste curable with actinic radiation and, if desired, thermally, by 1) emulsifying an organic solution comprising 1.1) components curable with actinic radiation and, if desired 1.2) thermally curable components , to give an emulsion of the oil-in-water type, 2) removal of the organic solvent or organic solvents, 3) partial or complete replacement of the volume of solvent removed by water, to give a transparent powder coating comprising particles solid spherical, wherein the powdery paste is further mixed with, (4) at least one ionic thickener, especially anionic and at least one ionic associative thickener. 10. The process according to claim 9, characterized in that organic solvents miscible in water are used. eleven . The process according to claim 9 or 10, characterized in that the organic solvents are removed at temperatures that are below the glass transition temperature Tg of the binders. The process according to one of claims 9 to 11, characterized in that the solid spherical particles have an average size from 0.8 to 20 μm and in particular from 3 to 15 μm and also a maximum size of 30 μm. The process according to one of claims 9 to 12, characterized in that the powder pulp has an ion-forming group content from 0.05 to 1, preferably from 0.05 to 0.5 and in particular from 0.05 to 0.3 meg / g, a content of neutralizing agent from 0.05 to 0, preferably from 05 to 0.5, and in particular from 0.05 to 0.3 meg / g, and a viscosity of (i) from 50 to 1000 m Pas at a shear rate of 1000 s'1, (ii) from 150 to 8000 mPa at a shear rate of 10 s "1 e (iii) from 180 to 12,000 mPas at a shear rate of 1 s "1. The use of the powdery paste according to one of claims 1 to 8, or of the powdery paste prepared according to one of claims 1 to 13, for preparing transparent coating materials for automotive OEM finishing, automotive finishing and industrial coating. 15. A clearcoat material prepared from the pulp of the pulp according to one of claims 1 to 8, or from the pulp prepared in accordance with one of claims 1 to 13. 16. The use of the clearcoat material according to claim 15, to produce single-shell or multi-shell clearcoat systems in automotive OEM finish, automotive finish and industrial coating. 17. A formed part, particularly of metal, glass, wood and / or plastic, coated with a single-shell or multiple-cover transparent layer system, wherein the transparent layer or at least one of the transparent layers has produced a starting from the transparent layer material according to claim 15.