DE3802797C2 - - Google Patents

Abstract

Process and apparatus for the production of rapidly curing coatings on surfaces of wood, woodworking materials, cured or uncured, woven or unwoven substrates which may be impregnated with an impregnating resin and consist of paper, cardboard, nonwoven or woven fabric and metal foils or plastic films by applying a liquid coating material containing plastics or synthetic resins, and if necessary diluents, plasticisers, flatting agents, fillers, colour-imparting substances and additives, a predried layer of an aqueous, solvent-free and substantially pollutant-free dispersion of a binder having a high film formation temperature above 60<o>C, into which waxes or paraffins have been incorporated in a concentration - based on the solids content of the dispersion - of 3 to 10% or more by precipitation at a high temperature, being fused together to form a film by a brief thermal shock at a temperature considerably exceeding the film formation temperature. <IMAGE>

Description

The invention relates to a method for manufacturing fast-curing coatings on surfaces of wood, wood-based materials, Hardened or uncured, if necessary with impregnating resin impregnated, woven or non-woven carrier materials paper, cardboard, fleece or fabric, as well as foils made of metal or plastic by applying a liquid, synthetic resins containing coating agent and if necessary, diluents, plasticizers, matting agents, Fillers, coloring substances, additives and additives, and a device for carrying out this Process.

A problem in the production of fast-curing coatings the type described above are the one for the relatively long drying times and those occurring during processing Pollutants, such as formaldehyde or Skin-damaging solvents, such as those at UV curable systems must be used. For UV-curable Systems that still have relatively short drying times get along, you need photoinitiators, on the one hand are carcinogenic and to a yellowing of the other Apply coating layer. Not sufficiently hardened Areas often gass unpleasant smells for months Vapors, so that for this reason, the previously known Systems can not satisfy. Come in addition finally, in all, that the remainders remain at Processing hazardous waste, which in a complex manner must be disposed of.

The problems with solvents or other pollutants can indeed be significantly reduced, if - as in the  German Patent Application DE 31 12 694 C2 is proposed - aqueous dispersion in which acrylate polymer and at least one unsaturated polyester resin has been used, but allow short curing times, for example an immediate rewinding of a film with such a Plating has not been allowed to. In addition, in the aqueous dispersion of these Germans Patent monomers and oligomers are used the physiologically questionable in water-dilutable form are. The main difficulty, however, is that when curing these dispersions a thermosetting Film is created, which is thermally no longer deformable, what while it is desirable for the treatment of furniture surfaces, However, in many other applications is not necessary actually the production of coatings with predetermined Structures allows.

Also known from the published patent application DE 36 10 732 A1 become aqueous two-component clearcoat on the basis Methanolverätherter melamine and urea resins by Acid catalysts can not be hardened all these days meet demands made on such coatings. On the one hand, this results from the hardening of these two-component paints a turn thermally non deformable and no longer flowable thermosetting film and above all arise as pollutants formaldehyde and methanol, which is given the increased environmental protection provisions in many Use cases is no longer tolerable.

The invention is therefore based on the object, a method of the type mentioned in such a way that with Help of simple pollutant-free starting materials in one Method, which also without harmful Side conditions and residues expires, regardless of the  respectively used carrier material and the type of order The coating is crystal clear, durable and both abrasion-resistant also moisture-resistant coatings are created, the drying time is extremely short, so that even with highest processing speeds running roller machines without additional drying sections to be installed allow immediate winding.

To solve this problem, the invention provides that on the carrier material from a pre-dried layer an aqueous, pollutant-free, self-crosslinking and / or externally crosslinkable and / or precrosslinked dispersion free of volatile solvents of a thermoplastic Binder with a high, above 60 ° C lying Film formation temperature, in which by hot precipitation waxes or paraffins with a concentration - based on the Solid content of the dispersion - from 3 to 10% by weight have been incorporated by a brief temperature shock with a film forming temperature significantly excess temperature melted into a film becomes.

It has become extensive, the present invention underlying experiments that such Binder with high melting point or high minimum Film forming temperature (MFT) applied in a conventional manner can be, for example by rolling, doctoring, Spraying, filling, pouring or electrostatic Spraying, then when exposed to a very high temperature be subject to a sudden melting process and make a coherent film. This film formation under the temperature shock eliminates flow defects, like "orange peel effect", "rolling calls", "Squeegee", "raster effect" etc., which are very  often by even so careful recipe design and Viscosity control when applying liquid or pasty coating materials can not be avoided.

Due to the high melting temperature, or the high MFT, takes place immediately after leaving the temperature zone as well abruptly the solidification of the formed in the melting process Filmes, so that immediately after the temperature shock the Stackability, blocking resistance, windability, etc. as well at the same time, the resistance of the resulting surface given against mechanical and chemical action are. It has proved to be particularly advantageous Dispersions, e.g. B. based on acrylates, methacrylates, and their esters, nitriles, amides, vinyl acetate, Styrene, butadiene, vinyl propionate, isobutene, polyurethane, Use vinylidene.

It is preferred hard resins that are water-soluble, or made water-soluble by amination, used. Reactive resins that are water-dilutable or by means of suitable emulsifiers are dispersed / emulsified in water, can be used in conjunction with the corresponding catalysts, Promoters, accelerators (possibly latent settings) in the context of thermal curing for improvement Resistance to mechanical and chemical action contribute.

Hard resins are, for example, copolymers of styrene and acrylic acid, while reactive resins, e.g. B. polycondensable Systems (melamine-urea resins), polymerizable Resins (polyester, acrylic resins) or polyaddable Resins (polyurethane compounds) with the respectively corresponding catalysts or reactants could be.  

In the case of using latent hardener systems is the Production of 1-component materials possible. requirement here is that the light-off temperature at temperatures is above 100 ° C.

Water-dilutable liquids with reactive groups, the included as binder components in the chemical reaction can contribute to high solids content to lower the viscosity. You can go beyond that a clearly positive influence on the curing and Exercise film properties. Examples of such reactive Thinners are polyols, polyethers, polyetherols and epoxies each having at least two reactive groups. As recipe modules may influence the processing and film properties film former (polyvinyl alcohol), Plasticizer, wetting agent, defoamer, matting agent etc. are used.

The short temperature shock according to the invention - the short-term Heating also has the advantage that only the actually coating to be melted into a film is heated, and not, for example, the carrier material Also, if the layer is directly on the substrate has been applied - can be in various ways, for example, by radiant heat, achieve. Prefers However, it is provided that the pre-dried layer in direct contact with a temperature of about 100 to 200 ° C, than Energy source surface melted into a film is, where it is additionally favorable, if the Film immediately behind the leading to his education Heating device is cooled. According to the preferred Contact heating, either on a press surface or preferred on a heated calender roll, should also the possible  Cooling the film after the film forming heater possibly through a cooled calender roll. Instead or in addition, a non-contact Nozzle cooling be provided.

In the method according to the invention is just the Hot precipitation of high concentration of wax or paraffin of considerable importance, since in addition to an extreme fine distribution of wax or paraffin a kind Envelope effect of the individual dispersion particles Wax particles takes place. This results in an essential Improvement of the rheological properties and of it resulting very even coating layers, independent on the type of application of the layer. Come in addition nor that in Schmelzflußhärtung because of this envelope the dispersion particles by wax a very rapid even melting takes place, in which quite obviously also in detail not explored chemical Reactions occur as the ones formed in this way Layers besides a high mechanical hardness extremely resistant are also against liquids. It has shown that even after days fluids are not yet have passed through such a layer, which, for example in the coating of wood materials in the Regarding the liquid resistance of tables od. Like. plays a very significant role.

In addition, just allows the proportion of preferably hot precipitated waxes or paraffins very simple transfer method, such that the film initially formed on a roller or an endless belt and from there to the actual carrier is transferred. By this transfer method according to the invention can be especially porous and in their surface structure  provide rough surfaces with a smooth coating layer, without using excessively high levels of dispersant must be, since the means not damp on the porous surface must be applied and thus also can not penetrate to a high degree.

While the hot precipitation of waxes is particularly good Features brings, but not indispensable requirement for a usable result is a relatively high Wax content of the order of at least 3 to 10% or even more of particular importance. About that In addition, it has proved to be useful in the Wachseinfällung Combine wax and emulsifier.

The following waxes have for the purposes of the invention proved to be particularly suitable: montan waxes (montanic acid, or montan ester waxes), polyethylene waxes, polymer dispersion, Natural waxes, ethylene / vinyl acetate copolymers in Compound with suitable emulsifiers.

Not just the type of wax or paraffin used, but also have the selected emulsifier system decisive influence on essential processing and Surface properties (course, gloss, separation effect, hardness, Resistance). By adding appropriate emulsifiers can z. B. the loosening of the plastic band are completely thwarted, so that in this way an excellent laminating adhesive can receive.

The hardness, viscosity and gloss are also very high strongly by the respective emulsifier (on combination of different Emulsifiers), wherein an amount of emulsifier from about 2 to 6% based on the total recipe itself has proved to be very useful.  

Finally, as emulsifiers, the following substances have particular proven: oleic acid ethoxylate, fatty alcohol ethoxylate, Oleic acid alkylnolamide or, preferably, castor oil ethoxylate.

The transfer method also allows the very simple production structured films, namely by the roller or the tape has a corresponding surface structuring, The then accordingly after the transfer on the actual carrier is preserved.

With particular advantage, the transfer process in done in a way that the actual film formation, d. H. the fusion of the from a pre-dried dispersion layer resulting film, together with the transfer he follows.

It is also within the scope of the invention, several Layers of different materials to form a multilayer film to transfer stacked, wherein For example, the top layer of a binder layer can be a particularly good adhesion to the respective Cause carrier. In addition, for example, could even a special release layer can still be provided, so that the film is better off the roller or the belt, although this is generally due to the high growth or paraffin and the special type of incorporation is not required. By this wax content leaves except for a film of the invention very good from a smooth calender roll or a smooth Peel off steel or plastic tape again Carrier, for example, a paper web, a wooden plate od. Like., To be transferred.  

The inventive method and the used Substances make it possible in a further development of the invention also a completely new form of printing on backings, namely first on a transfer tape, or on a Transfer roller, a film-forming layer applied and is pre-dried, on which the individual layers of paint be printed, followed by the transfer on the actual carrier with the top coming to rest pre-dried dispersion layer and the training of the film by melt hardening. This kind of Printing obviously allows printing again any surfaces, including rough porous surfaces, not at all with conventional printing processes could have been printed. Add to that, that it does not matter how thick and rigid the actual Carrier is, since he is not by a printing press needs to be passed, usually is matched to paper or foil sheet and therefore For example, not easy for printing chipboard could be used, even if it is the surface finish would have allowed.

In this transfer printing of carriers is preferred the top layer of pressure an adhesive or adhesive layer to improve the adhesion on the support as well to compensate for surface defects of the wearer.

Another advantage of the transfer printing process according to the invention is because the transfer carrier, i. H. so the transfer belt or the transfer roller on which the actual Coating film formed or preformed and during of transferring is finally melted down, is printed by a web press and the Layer can be transferred to individual sheets. this makes possible  it, the existing much simpler built and trouble-free web presses also to use for printing sheets easily. This sheet printing is just for one of Main branches for which a coating is required nowadays is, namely the coating of foil sheet or Paperboard for the manufacture of packaging boxes, necessary.

For carrying out the transfer method according to the invention is a device in a further embodiment of the invention characterized by a between a drying device and a transfer station with heatable transfer rollers and an inlet and outlet for the coated Carrier circulating endless, made of plastic or metal existing transfer belt, which is on the return line from the transfer station an applicator happens.

Although the preferred transfer method can also be used Using a transfer roller on which the dispersion layer first applied and predried, to transfer from it to the actual carrier become. In practice, however, it is generally a transfer belt Alone for the greater length of advantage. The longer length of a transfer belt allows a trouble-free Arrangement of a large number of order stations as well an independent predrying of the melt-hardening, so that in practice a transfer device with Help a transfer roller only in special cases advantageous can be used.

Although the invention formed by Schmelzflußhärtung Film quite easily from the transfer tape  or the transfer roller can be replaced - by the nozzle cooling any loose particles are automatically removed - In some cases, however, it may be appropriate to do so before Application device a cleaning device for the To arrange transfer ribbon, even with any disturbances on the transfer belt remaining coating parts or Remove layers so that they do not interfere in the subsequent educated again  Film to be incorporated. The applicators for intermediate layers, for example one already addressed primer layer or a color primer layer od. Like., Are the drying device subordinate, in turn, the use of a Transfer belt instead of a transfer roller constructive and procedural benefits.

In addition to the use of cooled cooling rollers, or one Nozzle cooling, the heatable transfer rollers immediately follow, to a particularly abrupt Cooling of the formed by Schmelzflußhärtung Films and thus a completely unproblematic further processing to ensure the coated carrier may also be provided in the invention be that between successive transfer rollers a detour of the transfer belt opposite is provided for the carrier to be coated. By This detour can be both shocks of the tape as Even minor surface defects are not decisive impact on the quality of the finished film, because such errors are in the range of two consecutive Rollers are no longer in the same place Cover are arranged.

The transmission and, if necessary, cooling rollers can be especially easy to form as multiple calenders, at characterized by the extremely smooth surfaces of the Calender rolls an extra smoothing of the yes even very smooth by the Schmelzflußhärtung itself and contiguous film. The usage a transfer belt instead of a transfer roller moreover has the advantage that in this way the transfer printing much easier and under Use of commercial web presses take place can. For this purpose, the transfer tape  between the drying device and the transfer station simply by a commercial web press led, d. H. You can use commercial web presses to such a transfer printing device complete.

Further advantages, features and details of the invention will be apparent from the following description some embodiments and with reference to the drawing. Showing:

Fig. 1 to 5 various embodiments of the present invention apparatus for producing rapid-hardening coatings, wherein the dispersing agent is applied directly to the substrate to be coated and cured to a melt film,

Wherein a preformed film is transferred from one roller to the actual carrier Fig. 6 is a roll transfer device,

Fig. 7 is a schematic representation of an inventive belt-transfer device,

Fig. 8 is an enlarged detail view of two transfer rollers with an interposed detour guide of the transfer belt,

Fig. 9 is an illustration of a printing apparatus having a direct printing from roll to roll by applying a cover layer film according to the invention, and

Fig. 10 is a schematic representation of a transfer printing device, and

Fig. 11 is a schematic representation of a modified calender with additional circulating belt.

Before detailing the illustrated in the drawings different devices to carry out the coating method according to the invention will be discussed, are still some examples of recipes listed for suitable treated dispersion, with the help of which - how extensive the Experiments underlying the present invention shown have achieved very good results:

example 1 basic formulation Wt .-% 1. styrene / acrylate copolymer 15 2. Modified Styrene / Acrylate Copolym. 60 3. Wax emulsion 10 4. Defoamer 1 5. Montanester wax 2 6. Emulsifier 4 7. Water  8th 100

Example 2 1. styrene / acrylate copolymer 15 2. Modified Styrene / Acrylate Copolym. 40 3. polyurethane emulsion 20 4. Wax emulsion 10 5. Defoamer 1 6. Montanester wax 2 7. Emulsifier 4 8. Water  8th 100

Example 3 1. styrene-acrylate copolymer 15 2. Modify Styrene / acrylate Copolym. 40 3. styrene butadiene copolymer 20 4. Wax emulsion 10 5. Defoamer 1 6. Motanester wax 2 7. Emulsifier 4 8. Water  8th 100

Example 4 1. styrene / acrylate copolymer 15 2. Mod. Styrene / acrylate copolymer 55 3. Polyvinyl alcohol solution 5 4. Wax emulsion 10 5. Defoamer 1 6. Montanester wax 2 7. Emulsifier 4 8. Water  8th 100

Example 5 1. styrene / acrylate copolymer 15 2. Mod. Styrene / acrylate copolymer 40 3. Hard resin solution (30% in NH₃ / H₂O) 20 4. Wax emulsion 10 5. Defoamer 1 6. Montanester wax 2 7. Emulsifier 4 8. Water  8th 100

Example 6 1. styrene / acrylate copolymer 15 2. Mod. Styrene / acrylate copolymer 55 3. Water-soluble melamine resin 5 4. Wax emulsion 10 5. Defoamer 1 6. Montanester wax 2 7. Emulsifier 4 8. Water  8th 100

Example 7 1. styrene / acrylate copolymer 15 2. Mod. Styrene / acrylate copolymer 45 3. Ung. Polyester resin, water emulsifiable 10 4. Wax emulsion 10 5. Defoamer 1 6. Montanester wax 6 7. Emulsifier 3 8. Water  10 100

Example 8 1. styrene / acrylate copolymer 15 2. Mod. Styrene / acrylate copolymer 45 3. Wax emulsion (polyethylene wax) 4 4. wax emulsion (montan wax) 4 5. polyetherol 5 6. defoamer 1 7. Montanester wax 5 8. Emulsifier 4 9. Water  17 100

In all recipe examples, it is advantageous, respectively the last three positions as wax melt (95-100 ° C) in the previously completely perfectly dissolved Add the original in a thin stream with vigorous stirring.

The simplest apparatus for carrying out the coating process according to the invention is shown in FIG . It is shown with 1 to be coated carrier, which of course does not have to be as shown schematically a band, but of course a series of tracks, plates od. Like. Be could be. This support 1 is coated directly with the aqueous dispersion layer by means of a coating apparatus 2 comprising a transfer roller 3 and a dispersion applicator roll 4 , which is then predried in a drying apparatus 5 . This drying device can be for example a nozzle dryer or an IR line. After this predrying follows the actual melt flow hardening, which is already equipped in the simple embodiment shown in FIG. 1 as Intervallkontakthärtung with a plurality of heated contact rollers 6 . With 7 counter contact rollers are designated. Instead of heating all three successive rollers 6 could of course also be provided that, for example, only the first two heated and the last is cooled, in this way a particularly rapid shock-like re-cooling of the film formed in contact with the heated rollers 6 on the support. 1 to reach. The heating of the contact rollers 6 should be considerably above 100, up to 200 ° C, in order to ensure sufficient heating of the predried dispersion layer to values that are significantly above the MFT, even at high throughput of the carrier 1 and resulting short contact time ,

FIG. 2 shows an embodiment in which, instead of a calender roll arrangement for curing the predried film, contact hardening is carried out with the aid of a double-belt machine 8 . In the schematic embodiment according to FIG. 3, the coating of the carrier 1 takes place partly directly with the aid of the application device 2 , partly indirectly with the aid of coating devices 2 ' and 2 " operating on the belt 9 of the double-belt machine. In this case, a modified contact hardening is shown in this embodiment, which is illustrated schematically by the press with the jaws 10 and 11 . This heated cheek plates 10 and 11 cause the contact hardening and the transfer of the films of the coating devices 2 ' and 2'' on the support first

In Fig. 4, a device with a plurality of stations is shown schematically, as it is suitable for example for the covering pigmented coating of particleboard, hardboard or MDF boards. It comprises a plurality of application device 2, 2 ', 2'' and 2''' and correspondingly a plurality of dryers 5, 5 ', 5'' and 5''' and beyond a schematically arranged printing machine 12th

In Fig. 5, a device for contact hardening for the surface refinement of moldings in connection with the pressing process is shown schematically. The twin-roll coating device 2 applies a dispersion layer to the flat plates running on the transfer web 1 , which layer is in turn predried in a known manner in the dryer 5 at temperatures between 30 and 100 ° C. The plates are placed on an intermediate stack 13 and then processed in a molding press 14 to form parts, wherein the compression in the desired shape, the Schmelzflußhärtung of the first only pre-dried arranged on the surface of the flat plates dispersion layer. In a similar manner, other moldings such. As party plates and cups made of plain cardboard, since the coatings according to the invention - despite the use of aqueous emulsions as starting material - are extremely waterproof after the melt hardening.

Fig. 6 shows schematically a possibility of how a conventional calender for the transfer coating according to the invention can be converted. The layer applied to the hot calender roll 20 above with the aid of the coating devices 2, 2 ' is transferred in a transfer process to the strip 16 to be coated, wherein cooling is first performed to improve the detachment of the layer adhering to the strip 16 from the calender. For this purpose, the cooling belt 40 , which is cooled by the nozzle cooling device 41 , so that it rests cold in the outlet region of the belt 16 of the calender roll 20 at the bottom of this belt 16 and thus results in such a strong cooling, that a much better separation effect between the transfer layer on the belt 16 and the calender surface is given.

A preferred embodiment of an apparatus according to the invention for forming film coatings is shown in FIGS. 7 and 8. This is a transfer device, in which the film is applied by a transfer belt 15 to the actual carrier tape 16 to be coated. This carrier tape 16 is to be understood only schematically, since it does not have to be a tape which is wound from a roll 17 to a roll 18 . Instead, of course, instead of a belt 16 , a sequence of sheets could also be provided with a coating by means of the transfer coating device according to FIG . The transfer coating device comprises the actual transfer station 19 with heated calendar rollers 6 and counter-pressure rollers 7 and cooled calender rollers 6 a and counter-pressure rollers 7 a and the drying device 5 , which may include a controllable heated deflecting roller 20 within a hood 29 also schematically indicated by arrows radiant heaters. Between the transfer station 19 and the deflection roller 20 runs the transfer belt 15 , which may be a plastic or metal strip with an extremely smooth surface. An aqueous dispersion according to the invention, which is pre-dried in the drier 5 , is applied to this strip by means of an applicator device 2 which is again indicated only schematically in a manner known per se, as by knife coating, spraying or the like. A further layer, for example an adhesion promoter layer, can be applied to this dispersion by means of a further application device 2 ' , which in turn is only schematically indicated, which may also comprise different steps. These two layers, ie the pre-dried film layer 21 and the adhesion promoter layer 22 - which are shown schematically in dashed lines in Fig. 7 - are of the calender rolls 6 , which are heated to temperatures between 100 and 200 ° C, to the carrier 16 , and a other incoming in the inlet 23 carrier, pressed and thereby heated by the high temperature of the rollers 6, 7 so rapidly and suddenly to a temperature above their minimum film forming temperature MFT that the only pre-dried dispersion layer abruptly melts into a film that - favored by the Adhesive layer 22 - firmly adheres to the carrier 16 . The film thus formed is cooled by the cooled calender rolls 6 a, 7 a as soon as it has been heated, so that it can be wound onto the roll 18 immediately after exiting the transfer station 19 . The cooling additionally favors the detachment of the film according to the invention from the transfer belt 15 , whereby now the actual smooth abrasion-resistant film 21 is present as the uppermost cover layer which is particularly firmly connected to the support 16 by the underlying adhesion promoter layer 22 . In addition to the cooling rollers 6 a, 7 a , a nozzle cooling section 41 is also provided in FIG. 7, wherein, if appropriate, this nozzle cooling section can also completely replace the cooling rollers 6 a, 7 a . In any event, it has been found desirable, if not necessary, to provide cooling in such a transfer process after transfer to the belt being coated for substantially smoother, cleaner release from the transfer belt.

Between the cooling rollers 6 a and the applicator 2 is only schematically indicated as a box cutting and adhesive device 30 is provided to cut this at a periodically necessary change of the transfer belt 15 this first to stick a new transfer tape to the leading end to after the passage of the tape through the device then finally connect the ends of the new band section together. In this case, the cutting and gluing device 30 should be formed so that the bands are cut obliquely at the junction, the bevel cut should be placed so that it runs from top to bottom against the direction, so that when applying coating material on the transfer belt this can not be pressed by the rollers in the cut and could possibly form beads. If the material is suitable, it is in any case expedient to provide as seamless as possible a weld instead of a simple gluing of the transfer belt.

The schematically indicated at 31 lift-off device allows a very simple adaptation to different belt speeds. In the illustrated extended position with the foremost of the rollers 6 wide umschlingendem transfer belt 15 results in a relatively long contact time to the heated rollers 6 , so that very high belt speeds are possible. At lower belt speeds, the wrap must be correspondingly lower in order not to let the temperature in the layers 21, 22 become too high. This is achieved in that the lifting device 31 is adjustable, for. B. in the dashed position 31 ' , in which only a very short contact distance with the calender roller 6 and thus a correspondingly shorter time is achieved despite the small rotational speed, so that ultimately at constant temperatures of the rollers 6 in this way the desired actual heating the layers 21, 22 can be controlled.

In Fig. 8, a detour guidance of the transfer belt 15 between the calender rollers 6 is indicated in order to compensate for the effect of any impact or surface defects of the transfer belt. Between the two Heißkalanderwalzen 6 - the counter-rollers have been omitted for simplicity in this figure - is in turn before the Abhebewalze 42 to achieve this detour guide a nozzle cooling path 41 arranged to the necessary in the detour guide withdrawal of the transfer belt 15 of the tape to be coated 16 again to reach clean and smooth.

FIG. 9 shows a schematic printing device in which at the same time a coating according to the invention is also applied to the printing layers. The unwound from the roll 17 paper or foil strip 16 is in the schematic pressure stations 25 and 26 , which of course can be provided more than two, printed and then each dried with the aid of dryers 5 . Subsequently, in the application station 27, a dispersion according to the invention is applied to the printed strip surface and predried again in the third dryer 5 . With the aid of the heated calender roll 6 , the predried dispersion film is fused into a film, and then the paper web 16 printed in this way and at the same time superficially protected by a film according to the invention is wound onto a roll 18 . According to the cooling belt in Fig. 6, a cooling belt 40 is provided with a nozzle cooling path 41 in the arrangement of FIG. 9, to prevent the smooth film formed by the wrapping of the heated calender 6 on the belt 16 torn hot from the calender surface must become. The heat of the calender 6 is practically not affected by the cooling belt 40 , so that the heat of the calender through this cooling belt passes through the same effect as if the cooling belt were not present. However, the film layer formed now lies between the belt 16 and the cooling belt 40 , so that when leaving the calender surface, this film layer is still between the two bands. Only after passing through the cooling section 41 , the bands 40 and 16 are separated. However, this is now easily possible at this stage, since the layer formed by melt flow between the two belts is cooled down so far by the cooling section that the separation no longer causes any problems.

Finally, FIG. 10 shows a transfer printing device in which a transfer roller 15 made of metal or plastic is printed in a commercial web press comprising the various printing units 25, 26 and 28 instead of printing the actual carrier, preferably a paper web, onto which first applied with the aid of an applicator 2, an aqueous dispersion and has been pre-dried in a dryer 5 . The indicated three printing layers by the commissioned works 25, 26 and 28 are thus printed on the predried dispersion layer, which enters after passing through the printing press D in a transfer device 19 . In this, the fusion of the dispersion into a film takes place with simultaneous transfer of this film as well as the printing layers printed thereon and after the transfer under it to the support 16 .

In the illustrated embodiment of FIG. 10, the transfer device 19 again contains two hot calender rolls 6 with corresponding counterpressure rolls 7 , in front of and behind which takeup rolls 31 and 31 ' are arranged, which serve to increase the wrap angle of the calender rolls 6 in accordance with the running speeds of the strips 15 and 16 In order to be able to adjust in this way the desired heating of the preheated dispersion layer and thus the exact temperature at which forms by Schmelzflußhärtung the film according to the invention. At high belt speeds, the lift-off rollers 31, 31 ' are arranged in such a way that the course of the transfer belt 16 which is drawn out in FIG. 10 results. At very low belt speeds at which the belt should not be so long in contact with hot calender rolls 6 , so that the layer is not overheated, the take-off rollers 31, 31 'are in the respective dashed position, so that also the dashed position of the transfer belt 16 results. In this case too, the actual transfer station is again followed by a nozzle cooling section 41 in order to achieve a clean separation of the transfer belt and the coated belt 16 with the film formed thereon by melt flow. This separation is thereby facilitated by the blown in the nozzle cooling device 41 air blown at 44 between the separating bands and thus their withdrawal from each other is further facilitated.

The modified calendering device shown in FIG. 11 is intended especially for already existing calenders. After a direct coating of either the endless belt 1 or transported on the belt 1 single sheets using a coating device 2 shown in FIGS . 1 to 3 and a predrying through a dryer 5 , the belt 1 passes under a conventional calender 6 an existing calender, the According to the invention is supplemented by an additional circulating belt 32 made of metal or plastic. This band 32 allows using an adjustable lifting device 33, 33 a, which can also assume the position 33 ', 33 a' , an adjustment of the contact distance to the production speed, with a downstream nozzle cooling 34 after Schmelzflußhärtung the application layer on the tape 1 or ., the transported sheet ensures a rapid cooling, so that extremely high production speeds are possible. At 35 again cutting and adhesive devices are indicated to periodically change the band 32 can. Such a cutting and gluing device is intended especially when using plastic straps 32 , while metal straps, which in any case have a longer service life anyway, are replaced as a whole and prefabricated tape, but this is usually difficult to machine (aside roller bearing).

The invention is not limited to the illustrated embodiments. Thus, it would also be conceivable, in particular with regard to the transfer method described above, that the dispersion according to the invention not only predried enters the web press, but was formed by melt contact hardening of the finished film before entering the web press, which then applied together with the applied Printing layers and an adhesive layer in the transfer station 19 of FIG. 10 is applied to the actual carrier 16 to be printed. In this case, the transfer station 19 does not serve for film formation at the same time.

In addition, it would also be possible, for example, to provide air nozzles (cold air knife) coming from below in the outlet of the apparatus according to FIG. 7 in order to obtain a clean surface in the case of shingled sheets, in which the coating layer extends over the sheets, leaving an uncoated edge, of course Air section can be achieved by slightly lifting the sheets. It can be ensured by additional fan acting from above and below that the overlapping arc ends are not lifted too far by the cold air diameter, but only so far that a sharp clean air cut is achieved.

Claims (27)

1. A method for producing fast-curing coatings on surfaces of wood, wood-based materials, cured or uncured, optionally impregnated with impregnating resin, woven or nonwoven substrates made of paper, cardboard, nonwoven or fabric, as well as films of metal or plastic by applying a liquid, synthetic resins and optionally diluents, plasticizers, matting agents, fillers, colorants, additives and additives, characterized in that on the carrier material, a predried layer of an aqueous, pollution-free, self-crosslinking and / or externally crosslinkable and / or pre-crosslinked dispersion free of volatile solvents a thermoplastic binder having a high, above 60 ° C lying film forming temperature, in which by hot precipitation waxes or paraffins having a concentration - based on the solids content of the dispersion - from 3 to 10 weight -% have been incorporated, is melted together by a brief temperature shock with a film forming temperature significantly exceeding temperature to a film. 2. The method according to claim 1, characterized by the use of dispersions on the basis

• Acrylates, methacrylates and their esters, nitriles, amides,
• - vinyl acetate,
• - styrene,
• - butadiene,
• - vinyl propionate,
• - Isobutene,
• - polyurethane,
• - vinylidene.

3. The method according to claim 1 or 2, characterized by the use of reactive diluents based on

• - polyols,
• - polyethers,
• - Polyetherols or
• - Epoxides

each having at least two reactive groups. 4. The method according to any one of claims 1 to 3, characterized by the use of waxes based on

• Montan waxes (montanic acid, montan ester waxes),
• - polyethylene waxes,
• - natural waxes,

in conjunction with suitable emulsifiers. 5. The method according to claim 4, characterized in that as emulsifiers

• - oleic acid ethoxylate,
• Fatty alcohol ethoxylate,
• - Oleic acid alkylolamide

or castor oil ethoxylate. 6. The method according to any one of claims 1 to 5, characterized characterized in that the predried layer in direct Contact with a ca. 100-200 ° C hot, as Energy source surface melted into a film becomes.   7. The method according to any one of claims 1 to 4, characterized characterized in that the film immediately behind the cooled to its formation leading heater becomes. 8. The method according to claim 7, characterized that the film of a contact cooling on cooled calender rolls is subjected. 9. The method according to any one of claims 1 to 8, characterized characterized in that the predried layer by Applying the liquid dispersion to a transfer roller or an endless transfer band formed and transferred from there to the actual carrier is, wherein the transfer to the melting together a movie is effected. 10. The method according to claim 9, characterized a transfer roller or a transfer belt with a Surface structuring is used. 11. The method according to claim 9 or 10, characterized that several layers of different Materials are stacked in a multilayer film become. 12. Process for the preparation of fast-curing coatings on printed carriers according to claims 9 to 11, characterized in that on a transfer belt or a transfer roller, first a dispersion layer applied and pre-dried, to which the individual Color layers are printed, and that subsequently the transfer to the actual Carrier with predried to come upstairs  Dispersion layer and the formation of the film by melt hardening. 13. The method according to claim 12, characterized that on the uppermost printing layer, an adhesive or Adhesive layer to improve adhesion on the support and to compensate for surface defects the carrier is applied. 14. The method according to claim 12 or 13, characterized that the transfer carrier (transfer belt, Transfer roller) printed by a web press and transfer the layer to single sheets becomes. 15. Device for carrying out the method according to one of claims 9 to 14, characterized by a between a drying device ( 5 ) and a transfer station ( 19 ) with heatable transfer rollers ( 6, 7 ) and an inlet and outlet for the carrier to be coated ( 19 ). 16 ) circulating endless, made of plastic or metal, transfer belt ( 15 ), which passes on the return path from the transfer station ( 19 ) an applicator device ( 2 ). 16. The apparatus according to claim 15, characterized in that a cleaning device for the transfer belt ( 15 ) is arranged in front of the application device ( 2 ). 17. The apparatus of claim 15 or 16, characterized by the drying device ( 5 ) downstream application devices ( 2 ' ) for intermediate layers ( 22 ). 18. Device according to one of claims 15 to 17 , characterized in that behind the heatable transfer rollers ( 6 , 7 ) cooled cooling rollers ( 6 a, 7 a) are arranged. 19. Device according to one of claims 15 to 18, characterized in that between successive transfer rollers ( 6 ) is combined with a cooling path detouring of the transfer belt ( 15 ) relative to the carrier to be coated ( 16 ) is provided. 20. Device according to one of claims 15 to 19, characterized in that the transfer rollers ( 6, 7; 6 a, 7 a) are designed as multiple calenders. 21. Device according to one of claims 15 to 20, characterized in that the drying device ( 5 ) in addition to a heatable guide roller ( 20 ) controlled switchable, the transfer belt surface opposite heater. 22. Device according to one of claims 15 to 21, characterized by a lift-off device ( 33, 33 a; 33 ', 33 a') for controlling the contact time at different transfer belt speeds by different wrap of the calender roll ( 6 ). 23. Device according to one of claims 15 to 22, characterized by a cooling device ( 6 a, 7 a) downstream cold air knife for separating the continuous film at overlapping bow. 24. Device according to one of claims 15 to 23, characterized in that for transfer printing, the transfer belt ( 15 ) between the drying device ( 5 ) and the transfer station ( 19 ) is guided by a web-fed printing press.