SE433061B - SET TO HEAT PRESSURE A DECORATIVE LAMINATE WITHOUT A PRESSURE PLATE - Google Patents

Description

8604836-6 10 15 20 25 30 35 2 ter. Although this printing is very good, the design of the decorative laminate cannot be considered satisfactory if the resin layer on the surface of the laminate does not have a three-dimensional pattern or gloss which is suitable for printing. Particularly in the case of wood-fiber-patterned decorative laminates, it has been difficult to align the part of the printed, decorative sheet which represents wood recesses (hereinafter referred to as the trachial part) with the recesses which are obtained during the pattern pressing.

For the production of this type of decorative laminate, a so-called wiping method is used, in which a decorative laminate is molded using a press plate with a three-dimensional pattern, which is obtained by etching the surface of a metal plate, such as stainless steel, whereupon the obtained decorative the recesses of the laminate are painted with ink to color the trachial part. With this method, however, it is extremely difficult in practice to choose a paint which adheres sufficiently strongly to the surface of the decorative laminates and still has the other desired properties. Although, for example, a transparent resin is coated with the paint layer to protect it, it is very difficult to achieve the original surface conditions and properties of the decorative laminate of thermosetting plastic. Furthermore, in the metal press plate produced by etching or sandblasting, the casting of the protruding parts and the recesses is sharp, while the protruding part is substantially smooth and the part with recesses is roughened. Decorative laminates produced using such metal press plates have thus been incorrect with respect to the reproduction of the enamel and natural material surfaces.

The main object of the present invention is therefore to provide a method for producing a decorative thermoset sheet using a press plate which is improved in terms of release capacity and service life and which is inexpensive. The object 10 15 20 25 30 35 _., _____._...._. $ _ _., _., 8004836-6 3 is achieved by the method defined in the appended claims. The invention will be described in more detail below with reference to the accompanying drawings, which show exemplary embodiments. Fig. 1 shows schematically in section a conventional decorative laminate. Fig. 2 shows schematically in section a decorative laminate according to an embodiment of the present invention. Fig. 3 shows schematically in section a pattern press plate for carrying out the invention, which plate has an enamel layer. Fig. 4 schematically illustrates a method of manufacturing a pattern press plate with an enamel layer. Figures 5 and 6 show in section embodiments of the pattern press plate, which has an enamel layer. Fig. 7 schematically illustrates a method for hot pressing of decorative laminate elements by means of a pressing plate according to Fig. 3. Figs. 8, 9 and 10 show in section other embodiments of a pattern pressing plate, which reaches an enamel layer. Figures 11 and 12 show in section embodiments of a pattern press plate, which has an enamel layer with roughened, projecting parts. Fig. 13 shows in section a decorative laminate, which is produced by means of the pattern press plate in Fig. 12. Fig. 14 shows in section an embodiment of a pattern press plate with an enamel layer with a roughened surface. Fig. 15 shows in section a decorative laminate, produced by means of the pattern press plate according to Fig. 14. Figs. 16 and 17 schematically illustrate in section methods for hot pressing a decorative laminate element by means of a pattern press plate, which has an enamel layer. Figs. 18, 19 and 20 schematically illustrate in section methods for causing a dye to adhere rugged protruding portions of an enamel layer, and Fig. 21 shows in section a decorative laminate in which recesses have been roughened and dyed.

According to Fig. 1, in the surface of a decorative laminate 1, which is made by means of a conventional press plate of metal or resin, the sharp protrusions and recesses of the press plate are reproduced and a uniform pattern of protrusions and recesses cannot be obtained. In contrast, according to Fig. 2, an operative laminate 2 according to the present invention has a smoother surface than a conventional decorative laminate. The decorative laminate 5 of the present invention is advantageous in that its three-dimensional surface is smooth and suitable for. reproduction of three-dimensional color, ceramic, tile, clausong, natural stone patterns, etc. The decorative laminate according to the present invention is produced by means of a press plate or a pattern-pressing plate having an enamel layer 6 on a metal substrate 5 of steel, cast iron, copper, aluminum, stainless steel or the like, such as is shown in Fig. 3. The enamel layer 6 is provided by coating the substrate with a suitable glaze and firing. A press plate, which is suitable for the production of a decorative laminate with different patterns, is provided by providing a three-dimensional pattern and a gloss pattern, i.e. roughened portions on the surface of the enamel layer. The enamel press plate 20 has been found to be advantageous in the manufacture of laminated decorative thermoset sheets in the following respects: (1) Suitable release capacity is achieved with thermosets such as melamine formaldehyde plastics, since the surface of the enamel layer is very hard and fine. (2) The production of protruding parts on the surface of the enamel layer can take place relatively easily, for example by screen printing with fritted paint. I (3) Roughening of protruding parts can easily take place by mixing, for example, a matting agent in the free paint. (4) The bottom surface of the enamel layer recesses is very smooth, so that a dye adheres to only a small degree and can be easily removed. Thus, the dye can easily be made to adhere only to the roughened surface of the protruding parts. (5) A decorative laminate having a color pattern, which fully conforms to the three-dimensional pattern of the plate, can be obtained since the adhesion of the dye to the roughened surface is completely transferred to the recesses in the decorative laminate. when an enamel-coated press plate with roughened and colored protruding parts was used. (6) The dye transferred to the decorative laminate is thereby bound due to the melting of the thermosetting plastic of the decorative laminate.

Although the press plate is described as a flat plate, it may also be in the form of a roller. The method of producing the recesses and the protruding parts of the enamel layer of the press plate will now be described. In order to achieve smooth recesses and projecting parts of the enamel surface of the substrate, a method according to Fig. 4 is possible, according to which a glaze 8 is sprayed by means of a spray gun 9 on the surface of the substrate 7, whereupon firing takes place to form a surface 10 with a arbitrary three-dimensional pattern. Alternatively, as shown in Fig. 5, after uniform application of a glaze to the three-dimensional pattern of the substrate 11, a three-dimensional pattern surface 12 can be provided by firing. It is also possible according to Fig. 6 to apply glazes of more than one kind with different melting points on the surface of a substrate 13 in a pattern or in an arbitrary manner. A three-dimensional pattern is achieved by firing at a temperature which can burn the glaze 14 with the highest melting point and by melting the glaze or glazes 15 with a lower melting temperature. The surface of a decorative laminate, which is pattern pressed with a press plate made in one of these ways, has a smooth, three-dimensional pattern, as shown in Fig. 2.

A decorative laminate having a continuously curved surface formed by alternating recesses and protruding parts will be described as a preferred embodiment of a decorative laminate made by means of a press plate having an enamel layer with a smooth, three-dimensional soo4ss6 ~ al 10 15 20 25 30 35 6 sional pattern.

The press plate used in this embodiment can be prepared by pretreating a metal substrate, using processes such as degreasing, a spray gun being used to coat the substrate with a slicer obtained by adding a glass frit to a mill additive and water, - the dough is ground and kneaded in a ball mill. Then the coated substrate is burned. The frit used may be of a general type and have as main components, for example, SiO 2, Aβ 2 O 3, B 2 O 3, Na 2 O, K 2 O, CaO, ZnO, MgO and the like. The milling additive may be a suspending agent, such as clay, an emulsifier such as tin oxide, color borax or an electrolytic material, such as magnesium carbide.

The firing takes place at a temperature which is higher than the melting temperature of the frit, mainly in the range É00-90000; The molten frit is in the form of a viscous liquid, so that the surface tension tends to minimize the surface area. This, together with the flowability of the molten frit, serves to make the sharpness of the protruding parts and recesses softer, so that rounded protruding parts and recesses are obtained. It is possible to achieve a very suitable flowability and the same roundness in recesses and protruding parts by appropriately choosing the composition of the frit and the temperature conditions. Thus, an enamel layer can be obtained, which evenly corresponds to the surface of the metal substrate and has recesses and protruding parts with the same dimensions. Although the three-dimensional pattern of the enamel layer of the press plate and the three-dimensional pattern of the decorative laminate obtained by using the press plate are opposite, they have the same external appearance. Therefore, the three-dimensional pattern of the enamel layer must not be made opposite to the three-dimensional pattern of the decorative laminate intended for production. Thus, it is possible to provide a press plate which has a sinusoidally curved surface, which is provided by means of alternating recesses and projecting parts, i.e. a horizontally symmetrical curve.

A laminated decorative thermoset sheet is produced by a conventional method using a press plate. The thermosetting plastic used here may be melamine formaldehyde resin, dialyl phthalate resin, polyester resin, guanamine resin or the like. As shown in Fig. 7, a decorative laminate element, such as resin-impregnated lamella paper 16, a printed decorative sheet 17, on which a desired pattern is printed and which is impregnated with resin, is laminated, and a resin-impregnated overlay paper 18. A press plate 19 is placed over it. , so that its enamel layer, which has a three-dimensional pattern, is in contact with the paper 18. Plywood can be used instead of the lamella papers, if desired. A decorative laminate with an even three-dimensional pattern and with a luster, which corresponds to the enamel, is obtained by hot pressing. This decorative laminate has no sharp angles in the three-dimensional pattern, whereby it acquires a natural appearance and does not tend to accumulate dirt in its recesses and is easy to clean.

Example 1 A steel plate with a thickness of 1.6 mm was degreased.

Slicks are prepared, which consisted of a frit with the main components SiO2, B2O3, Aβ2O3, Na2O and similar waters, a suspending material, such as GAIROME clay (refractory clay) and other additives. The slicker was sprayed by means of a spray gun on one surface of the steel plate to form an arbitrary three-dimensional pattern thereon.

Firing at 850oC took place for 3 minutes and a pattern press plate with an enamel layer on one surface was obtained.

This pattern press plate was used to make a decorative laminate of melamine formaldehyde resin. Thus, a decorative laminate of melamine formaldehyde resin with a smooth, three-dimensional pattern and improved luster was obtained. No defects could be noted on the pattern press plate after over one hundred repeated pattern presses 00 10 15 20 25 30 35 4836 ~ 6 1 8 regardless of the fact that hot pressing took place at a temperature of 140 ° C and a pressure of 80 kg / cmz.

Another method for creating a three-dimensional pattern on a press plate will now be described.

After manufacturing an enamel layer on a metal substrate using a conventional method, protruding parts or recesses can be provided. For example, it is possible to print a protruding pattern on the surface of an enamel layer by screen printing using an ink with a glass content of more than 10%, for example free ink, and then burn. It is also possible to apply an adhesive in the desired pattern to the surface of the enamel layer, to sprinkle glass powder, called fritta, over it and to burn after the removal of the frit_on other parts than the pattern. It is further possible to create a protruding pattern on the surface of the enamel layer by using a transfer sheet with a pattern formed thereon, such as a paper sheet or a plastic film, by means of printing ink, which contains a pigment and frit and then burn. the methods of providing a protruding part or a recess of the enamel layer on the press plate will now be described in more detail.

In the embodiment according to Fig. 8, a primer coating layer 22 is applied to both sides of a metal substrate 21, although these primer coating layers are not essential. The layers are preferably arranged because they improve the adhesion between a covering enamel coating layer and the metal substrate and increase the service life of the press plate. Furthermore, it is advantageous to apply the primer coating layer to the back of the metal substrate to prevent warping 7 and corrosion of the press plate. A so-called black primer, containing cobalt oxide, can be used for the primer layers. After complete firing of the primer coating layers 22 and cooling of the substrate, a covering coating enamel layer 23 is provided on each of the primer coating layers 22. For the coating enamel layer, a slicer 10 can be used, i.e. a glaze, which is prepared by a grinder additives are mixed in a commercially available enamel frit, after which the mixture is processed in a ball mill. The coating method can be chosen arbitrarily. however, the coating is conveniently done by spraying, as the press plate has large dimensions. Like the base coat layers 22, enamel layers 23 are preferably provided on both sides of the substrate Z1.

The finished surface of the enamel layer can be varied by a suitable choice of frit and mill additives, the viscosity of the slicer during coating, coating method, burning temperature and the like. A desired finished surface can thus be achieved by modifying a smooth state to a somewhat wavy and even state. To create a three-dimensional pattern, the above methods can be used. Simple methods among these are to increase the viscosity of the slicker, to equalize the levels and to increase the diameter of the slicker droplets by reducing the air pressure of the spray gun. In this case, the fluctuations with respect to the pattern height of the enamel layer need to be kept within a certain range because excessive fluctuations tend to cause an irregular transfer of ink to the layer during screen printing or during the transfer procedure. As for the surface gloss of the enamel layer, the desired gloss can be obtained by varying between a state, corresponding to a completely reflective surface, to a state with a completely matt surface. The matting of the enamel layer surface can easily be achieved by adding a matting agent to the glaze or by lowering the firing temperature. Furthermore, the surface conditions of the enamel layer can also be changed by choosing glazes with different particle sizes or different melting points. In both cases, the enamel layer should not be too thick, preferably below 500 μ. If it is too thick, it can lead to breakage due to the pressure during hot pressing.

Methods for providing protruding parts -24 on _. ._.-...._.-.-...._._.._......-.-.-_.__ »7-", V- .. «-.- ...-...-... ............. ,, .._, 8004856-6 the surface of the burnt enamel layer 23 by screen printing or by transfer as according to Fig. 8 now described in detail.

The method in which screen printing is used will first be described. The screen printing can be done using cloth with 100-74 μm mesh openings or preferably for the present method 250-210 μm openings. In it . In the latter case, the decorative laminate produced due to the thickness of the ink layer will have excellent three-dimensional effects. Mesh size, thread diameter, raster thickness, raster material and the like are determined on the basis of desired effects, the desired fineness of the pattern, etc., but cloth with 590-58 μm openings with monofilament threads or multifilament threads of new -1S lon or polyester are usually used. As far as the printing ink is concerned, commercially available free printing ink can be used, ie commercially available printing glass frit, which is finely ground and kneaded in canvas printing oil.

The method of using transmission will now be described. A predetermined pattern of free-print ink is printed on a surface of a base material, such as a sheet of paper or a film, by the desired printing method, such as screen printing or photographic printing. Screen printing allows the printing of thick patterns and photographic printing allows the printing of fine patterns. the transfer method can be arbitrarily selected from conventional methods such as a method for providing a lacquer transfer layer on the surface of the coating enamel layer and for transfer by pressing or a method for providing a lacquer transfer layer on the surface of the transfer paper and for transferring it directly to the transfer paper. the surface of the enamel layer. the transfer method is advantageous in that the transfer paper can be printed in advance and the actual deaf transfer can easily take place by means of the water transfer method or by means of a simple machine. However, the thickness of the ink layer obtained is limited, and the height of the raised ink layer is slightly lower evenly, u,, ._ _ ..........._.__._.-.-- _._..-...._- _. _ - 10 15 20 25 30 35 8004836-0 11 brought with direct printing by screen printing.

Modified embodiments of the method of producing a three-dimensional pattern by screen printing or transfer will now be described. In the embodiment of Fig. 9, a pattern is printed by screen printing or by transfer to a coating enamel layer 25 using a free print ink having a higher specific gravity than the enamel layer 25. Upon firing, the temperature is increased to a point where the enamel layer 25 melts. The free-printing ink part then sinks into the enamel layer 25 and produces recesses 26. Different finishing surfaces can also be obtained by a suitable combination of screen printing and transfer.

Both of these procedures can be repeated to achieve better effects. For example, several printing cloths of different thicknesses can be used to vary the height of the projecting cells in several steps. The gloss can also be varied by changing the ink composition. In the production of a press plate of this kind, the transfer of the ink layer and the firing can be repeated or the firing can be carried out after a plurality of transfers of the ink layer. Fig. 10 shows an embodiment in which this method is used to provide low, projecting parts 28 and a high, projecting part 29 on an enamel layer 27. With such a press plate a decorative laminate with recesses of different depths can be obtained.

As shown in Fig. 11, it is further possible to have a matte surface 33 on a projecting part 32, which is formed on the enamel layer 31 on the press plate. The matting of the upper surface of the protruding part can easily take place by using matting printing ink, which is obtained by mixing a matting agent in the free-printing ink, which is to be transferred to the enamel layer or the coating enamel layer by screen printing or transfer.

Alternatively, it can be done by mixing coarse particles with a low melting point, such as aluminum or zirconia, in the ink. In this case, firing must take place at a temperature of 6% 10 15 20 25 30 35 lm FIN] | 1lUllÉ; Y '12 temperature, at which aluminum or zirconia does not melt. In order to emphasize the matt surface of the protruding part and to improve the appearance, the coating enamel layer 31, which forms the recesses, can preferably be. plain. The slicer composition and firing ratio must be such that the surface of the recesses can be smooth as a mirror surface or have 50% mirror reflection at an angle of incidence of 600. However, the surface of the coating enamel layer need not be smooth but may have small irregularities and protrusions. A decorative laminate, which is molded by means of the press plate according to Fig. 11, has a matt surface in the bottom of each recess and a smooth surface on the protruding parts and therefore has a very advantageous appearance. With a conventionally etched metal press plate, the recesses become matte and the protruding parts of the decorative laminate thus become matte while the recesses are smooth. It is difficult to produce a decorative laminate of the kind which can be achieved by the present invention by means of this kind of press plate.

Various embodiments of a decorative laminate having such matte surfaces will now be described. In a first embodiment, shown in Fig. 12, a raised ink layer is printed on the surface of a coating enamel layer 34 by means of a thick printing screen using a free ink containing a matting agent. By firing at the appropriate temperature, the sides 36 of the protruding portions 35 are melted and joined to the coating enamel layer 34 to form a glossy surface. Only the surfaces 37 are matte. A decorative laminate manufactured by means of the press plate according to Fig. 12 has rounded shoulders 39 of glossy projecting parts 38 and matte bottom surfaces in the recesses 40. A decorative laminate with a plate pattern is easily obtained with this method. Such a decorative laminate can be produced by means of a press plate, which is obtained by printing a part corresponding to the plate joint, using a layer printing ink, containing a matting agent, and then firing it. This decorative laminate is very similar to real tiles because the tile edges are rounded and the joint parts are matt.

The second embodiment is shown in Figs. 14 and 15. According to Fig. 14, it is possible to provide an ink layer 42, which has the same level as the coating enamel layer 41 and which is matt on the surface, by adjusting the specific gravity of the free-print ink, which contains a matting ink. means, or by adjusting the firing temperature.

A decorative laminate made with this press plate is shown in Fig. 15. Its surface is substantially smooth but has to some extent matte portions 43 and glossy portions 44. It is thus suitable as a decorative laminate with a pattern of natural stone or the like.

The method of producing a laminated decorative thermoset sheet by means of a press plate having a matte surface produced in the manner indicated above does not differ fundamentally from the above-mentioned methods. The barge making method will be described with reference to Fig. 16 using a decorative melamine formaldehyde resin laminate as an example. over an enamel layer on a press plate 45, in turn, a coating paper 46 impregnated with melamine formaldehyde resin, a printed decorative sheet 47 also impregnated with melamine formaldehyde resin, a barrier paper 48 also impregnated with melamine formaldehyde resin, if required, are placed. a required number of slats 49 impregnated with phenolic resin and a sheet 50 which prevents warping. Several such combinations are stacked and provided with pads in a hot press for hot pressing. The rear surface of the press plate is in contact with the rear surface of the decorative laminate intended for manufacture. Thus, if an enamel layer is also arranged on the back of the press plate, this is advantageous in that a special release paper or a release film is not required because the enamel layer has a release capacity.

The pressing conditions may be the same as in a conventional method for producing a decorative laminate of melamine formaldehyde resin and need not be described in more detail. The preferred temperature is a maximum of 150-160 ° C, the pressure is SO -120 kg / cm 2, the heating time 15-30 minutes and the cooling time 15-30 minutes.

Protruding parts of the ink layer can be formed of the enamel layer on the back of the press plate, so that both sides of the press plate can be used for the production of decorative laminates. Since the decorative laminate elements can be placed on both sides of the press plate, the required number of press plates 51 can be half of what is normally the case when pressing an element stack. The number of decorative laminate elements, which can be pressed at the same time, can be increased due to this. In this case, two sets of decorative laminate elements, such as the cover paper sheet, the printed decorative sheet, the lamella sheets, etc., can be placed between the press plate 51 and a press plate 52. A release paper sheet 53 should be placed between each such set.

Example 2 A cold-rolled steel plate with a thickness of 1.6 mm. For the production of an enamel layer was cut to predetermined dimensions and degreased, pickled and cleaned with water. A black primer with the following composition was sprayed uniformly on both sides of the steel plate.

After drying, the plate was fired, maintaining a maximum temperature of 870 ° C for 3 minutes.

Black primer composition: round layer fritca ioo parts by weight GAIROME clay 7 parts by weight Feldspar 3 parts by weight Borax 0.75 parts by weight Magnesium carbonate 0.25 parts by weight Water 40 parts by weight.

White coating enamel with the following composition was sprayed uniformly over both sides of the steel plate, on 10 15 20 25 30 35 .20 min heating, 80Û4836-b 15 to which the primer has already been applied. After drying, firing was carried out, with a maximum temperature of aào ° c bibenöils for 2 min. White opaque coating enamel composition: coating enamel surface 100 parts by weight GAIROME clay 5 parts by weight Tin oxide 8 parts by weight Magnesium carbonate 1 part by weight Water 50 parts by weight.

The surface of the resulting covering coating enamel layer had excellent gloss and smoothness. Parts corresponding to the joints of hexagonal ceramic plates were printed on the enamel layer surface using a printing cloth with an opening size of 210 μm. The ink is produced by kneading canvas printing oil with a commercially available printing frit (already primed) with the addition of matting agent. Burning took place with a maximum temperature of 750 ° C for 2 minutes. The edges of the ink parts were shiny and rounded by melting and the tops of the ink parts were matte. The ink layer also formed protruding portions in one piece with the cover enamel layer to obtain a press plate. A decorative laminate of melamine formaldehyde resin was pressed using the press plate.

A printed decorative sheet, namely a titanium sheet of paper with a printed pattern of ceramic tiles, was made in advance. Hot pressing was performed in a conventional manner. Pressing according to the hot-cold method was performed under the following conditions: 45 ° C maximum temperature, 80 kg / Cmz pressure and 20 minutes cooling. No release sheet was used. The decorative laminate thus obtained had a well-adapted, smooth, enamel-like surface with a printed pattern on the protruding parts and matte parts corresponding to the joints of the ceramic tiles, these parts being very similar to real tile joints. The decorative laminated sheet of melamine formaldehyde resin as a whole showed a look that was very similar to a real flat surface. The press -80080036-6 10 15 20 25 30 35 16 plate was used during more than 100 presses.

Example 3 Screen printing of the combination shown below was performed on the surface of a cover enamel layer obtained by a method corresponding to that given in Example 2. §R Cloth openings Pattern Printing ink l 100 um Stone grain texture Glossy 2 250 um Modified plate joint Matt After performing printing no. 1, the ink layer was dried by heating to l00 ° C. After drying, printing No. 2 was performed. Firing then took place to integrate the ink layer with the cover aluminum layer. The firing conditions corresponded to those given in Example 2. The surface of the thus obtained press plate was shiny and protruded slightly in parts, corresponding to the stone grain texture. It was slightly raised and dull in parts, corresponding to the tile joints. It was also rounded and glossy in the protrusions of the protruding ink layer. A decorative laminate of melamine formaldehyde resin was then molded using this enamelled plate as a press plate under the same conditions as those given in Example 2.

The resulting decorative laminate had in some places a look similar to tile joints and had a fine stone grain texture in places that corresponded to the surface of the tiles.

Thus, an appearance was obtained which better resembled straight plates than in the embodiment according to Example 2.

Example 4 A sheet of paper impregnated with dialyl phthalate was placed over a plywood board with a thickness of 4 mm. Hot pressing was performed using a pressing plate according to Example 2 at a temperature of 130 ° C and a pressure of 10 kg / cm 2 for 10 minutes. The press plate was removed without the use of release sheets. The decorative laminate of dialyl phthalate had an appearance similar to that of the decorative laminate of Example 2.

Example 5 In preparing the press plate of Example 3, stone grain texture was pre-printed on a transfer paper sheet. This printed pattern was transferred to the surface of the cover enamel layer. A printing process was thus eliminated by this transfer. The pressure plate had the same appearance as in Example 3.

Example 6 Black primer (SG-Q, manufactured by Nihon Frit Co., Ltd) was uniformly applied to both sides of a 1.6 mm thick pretreated steel plate to provide an enamel layer. Burning was performed with a maximum temperature of 870 ° C for 3 minutes. Semi-matt, white cover enamel (manufactured by Nihon Frit Co., Ltd) was also applied on both sides of the plate. Burning was performed again with a maximum temperature of 750 ° C for 2 minutes. Drinking of parts, corresponding to trachial parts of wood grain, was performed with matte printing ink using a printing cloth with 74 μm openings on the surface of the cover enamel.

Purification was performed again with a maximum temperature of 730 ° C under Zxnin. The enamelled plate thus obtained was the semi-matt cover enamel surface and completely matt in parts corresponding to the trachial parts of the wood grain. The approaches of the ink layer were not rounded but maintained sharp. The enamelled plate thus obtained was used as a press plate. Hot pressing was performed using a conventional method using a printed decorative sheet with the printing pattern in Japanese oak and impregnated with melamine formaldehyde resin (Nika resin, manufactured by Nihon Carbide Industries Co., Inc.). The thus obtained decorative laminate of melamine formaldehyde resin had recessed trachial portions. These trachial parts were carpeted and produced a decorative laminate with a superior design.

According to the present invention, it is possible to produce a decorative laminate in which a dye is fixed at the recesses by using a press plate which holds the dye in the matte parts of the projections formed on the enamel layer of the press plate. i .. _.._..-, ......__..........._..._...._ ,,. ~ ....._. ........__......_ .. -.._ ___.-. The dye used can be chosen freely if it is compatible with the molten thermoset during the molding process and it may be a pigment. Various studies' have been done to check the durability of the obtained decorative laminates. As a result of these studies, it has been found that the colored parts of the obtained decorative laminate are stable if a dye is used, which in addition to dye components such as pigments contains a resin, such as a binder, which resin is the same thermoset used for the decorative lamina-. or a thermosetting plastic, which is compatible with such a thermosetting plastic in the decorative laminate and has a lower curing temperature than the thermosetting plastic in the decorative laminate and has a lower curing temperature than the thermosetting plastic in the decorative laminate. The result of a test with the adhesion of the various dyes fixed to the decorative laminate of melamine formaldehyde resin by the method described above is shown in Table 1. The calculations refer to the degree of bleaching after ironing the colored part of the decorative laminate 100 times with a cloth wet with lacktinner. 8004836-6 19 Table 1 Dye Binder Natural g Decorative laminate 5 I Durability I Printing ink Cellulose ba- Liquid I Poor A for these: resin (soluble in corrosive oil) | laminate rfyckfäfg cenumsa- e1- Rwanda in Tiuffeassrananae 10 B for de- ler acrylic base- (soluble in 'corative rat resin water) laminate 1 scfeen- Amyaharrs Fmande in' rinffedsszänanae: lighthouse-amg, (wsng: in Screen- IAQ oil) 'Alkyd resin,; Liquid = Good ink melamine resin; (soluble in * B 1 Oil) Å; Test pressure- Melamine resin l Liquid: Good 'color A - (soluble in; water) Test pressure- Epoxy resin Liquid Å Cod color s 1 (wa-ngr in 20. g Oil) Pigment A No Powder Bad Pigment B Vinyl Resin Powder å Bad Powder- Polyamide Resin 'Powder É Bad Color A; 25 Powder- Polyester resin Powder in Satisfactory color B - 1 Sample whole- Melamine resin Powder! God pigment | From the above table it can be seen that in decorative laminates of melamine formaldehyde resin the resistance of the colored parts is improved relative to the thinner ones by using a colorant which has as a binder a hardening plastic such as melamine formaldehyde resin or epoxy resin.

As for the powder paint B in Table 1, insufficient curing was achieved even though the binder was a curing plastic because the curing temperature was higher than the pressing temperature of the melamine formaldehyde resin decorative laminate. This relationship between the resin of the decorative laminate and the binder is applicable to decorative laminates of other thermosets such as dialyl phthalate and polyester resin. Dyes containing dye components and a binder may be in liquid or powder form. However, the powder form is preferred because it is more easily removed from the even parts of the press plate.

A method of holding the colorant only in the matte parts of the enamel layer of the press plate will now be described.

The so-called wiping method is easiest and preferable.

As shown in Fig. 18, a paint 62 is applied to the entire surface of an enamel layer 61 on the press plate 60 and the surface is wiped off with a blank or a sheet of paper. Thus, the dye is removed on a smooth part 64. The wiping is easy if the cloth or paper sheet is wetted with a solvent for the dye used. Although the dye on the smooth part 64 of the enamel layer is easy to wipe off, it is difficult to wipe it off on a matte part 65-H as the dye eats into the fine recesses of the surface. in practical manufacture, the pressing of the press plate can hardly be done manually because the press plate is quite large. Preferably, therefore, a wiping machine such as that shown in Fig. 19 is used. Thus, as shown in Fig. 19, a colorant 68 is applied to the entire surface of the press plate 67 by means of a coating roll 66. The colorant is scraped off by means of a wipe roller 69 which rotates in the opposite direction relative to the direction of movement of the press plate 67. If the dye is liquid, a rubber wiping roller is used. When the dye is a powder, a soft material such as a cotton roll can be used as a wiping roll.

With this method, wiping can take place over the entire surface of a press plate with a large area in a uniform manner and the colorant is left only in matted parts. Alternatively, screen printing technology can be used. As can be seen, a screen plate 70 used to provide the mat portions 73 on the surface of the enamel layer 71 is attached to the enamel layer 71 so that the line pulling portions of the printing fabric 70 and the mat of the enamel layer 71 are parts 73 are aligned. A colorant 72 is printed by screen printing so that only the matte portions 73 are colored. No special printing cloth for making the matte parts is required. A separate printing cloth, made from the same positive pattern, can alternatively be used. Especially when the printing cloth, which is used for the production of the matte parts, has a small opening size and a large thickness, the same printing cloth should not be used. Better results are obtained, since too much paint is then applied. Furthermore, the blank, which has a lower thickness and an aperture size of about 74 nun. When the positive son was used to make the matte parts, was not used but a corrugated positive with slightly narrower line drawing parts was used to make a printing cloth, the processability is improved because the dye does not leak. the matte parts of the enamel layer.

It is further possible to apply more than one color by dividing the matte parts between more than one printing cloth and coloring the matte parts with dyes with different shades. The decorative laminate thus obtained is colored in more than one color and its appearance is improved. In the above processes for applying one or more dyes to matte parts by the wiping method or the screen printing method, the water or the volatile material, such as a solvent, in the resin of the mat parts of the enamel layer can be removed by drying when a liquid dye is used. When too much such material remains, it can evaporate during the pressing of the decorative laminate and can lead to certain surface irregularities or pits in the decorative laminate. This need not be taken into account when a powdered colorant is used.

It is thus possible in this way to make the recesses in a decorative laminate of thermosetting plastic carpet and color them with the aid of a press plate, which has one or more dyes only on matt parts. The pressing method of the decorative laminate does not differ from that described with reference to Figs. 7, 16 and 17. The thermoplastic resin, which once melted during the hot pressing of the decorative laminate, forms matte recesses when pressed by means of the projecting mat. the parts of the enamel layer of the press plate and is combined at the same time with the paint applied to the protruding mat parts of the enamel layer of the press plate. By curing the thermosetting plastic, the colorant is securely attached to the recesses and is not retained on the enamel layer of the press plate.

The press plate can thus be used immediately in the next process for applying a colorant. The decorative laminate thus shown is shown in Fig. 21. This decorative laminate has smooth protruding portions 75 and the bottoms of the recesses 76 are matte and colored in the desired color by means of a colorant 77. The decorative laminates thus obtained are completely superior in appearance.

In particular, when a printed decorative sheet with a flat or stone pattern is used together with matte parts of an enamel layer with adapted sand grain or flat joint patterns (pressed pattern), the obtained decorative laminate is very similar to a real flat surface or ceramic surface and has a particularly advantageous appearance. When a printed decorative sheet with a wood fiber pattern is used together with the matte parts of an enamel layer on a press plate, which has a trachial pattern, a decorative laminate is obtained, the recesses of which are dyed with the color of the trachial part. In the decorative wood fiber laminate thus obtained, the recessed trachial parts and the colored parts are completely aligned as opposed to the conventional method (according to which the color of the trachial parts is printed on the printed decorative part). 30 8004836-0 23 tiva arket. Thus, the decorative wood fiber laminate is superior in design and the laminate is very similar to ordinary wood.

Example 7 A steel plate with an extremely low carbon content and a thickness of 1.6 mm for the production of an enamel layer was cut to a predetermined size and then degreased, treated and cleaned with water. A black primer was then sprayed on both surfaces of the steel plate. After drying, firing was performed, maintaining the maximum temperature of 870 ° C for 3 minutes. White enamel was applied in the same way on both surfaces. After drying, firing was performed again, maintaining the maximum temperature of 850 ° C for 2 minutes. The surface of the cover enamel layer thus obtained was glossy and smooth. Parts corresponding to the joints of hexagonal ceramic tiles were printed on the surface of the cover enamel layer using a 210 μm mesh printing cloth. The printing ink was prepared by powder coating cloth printing oil with a commercially available printing frit with a matting agent added (already primed). Burning took place, maintaining a maximum temperature of 750 ° C for 2 minutes. The edges of the printed parts were rounded and became glossy. The tops of the printed parts were made of carpet. The inked parts protruded from the cover enamel layer and were formed in one piece therewith.

A colorant with the composition given in the following Table 2 was applied to the surface of a press plate prepared according to the above method. The dye was wiped off with a cloth dampened with water and the dye remained only on the matte parts. 8004836-6 10 15 20 25 30 35 '24 Table 2 Melamine resin 100 parts by weight (Nika resin S-260 manufactured by Nihon Carbide Industries Co., Inc§) Carbon black 4 parts by weight Iron oxide based yellow pigment 16 parts by weight Iron oxide based red pigment 5 parts by weight In Water 100 parts by weight Surfactant 2 parts by weight Thickener 2 parts by weight A decorative laminate of melamine was molded using a press plate with an enamel layer, a dye adhering only matte parts after drying the water content of the dye. A titanium paper with a printed plate pattern was used as a printed decorative sheet and hot pressing was performed in a conventional manner. Mold production by the heat / cooling method was used at a maximum temperature of 145 ° C, a heating time of 20 minutes, a pressure of 80 kg / cm 2 and a cooling time of 20 minutes. No release sheet was used. The resulting decorative laminate had protruding parts with a smooth surface and a luster which corresponded to the enamel and a custom printed plate pattern as well as recesses ~ with a matte surface and a resistively colored pattern. The resulting decorative laminate as a whole was superior to heretofore in design. Its design was extraordinarily similar to a real flat pattern. In the colored recesses, the dye was integrated with the melamine formaldehyde resin and adhered strongly, so that no adverse effect could be noted after the decorative laminate was wiped 100 times with a thin wet cloth. Furthermore, the dye was completely transferred to the decorative laminate during mold making and no dye remained on the surface of the enamel layer after the mold was opened. 8004836-U 25 Exemgel 8 V As in Fig. 7, a screen cloth was used for applying dye to the enamel layer of the press plate. The screen cloth consists of a nylon cloth with a mesh size of 74 μm, a pattern with hexagonal chemical plates being used as a positive pattern, which was previously used for producing the matte surface on the press plate. The coloring of the matte surface of the decorative laminate was extremely simple with this method and allowed coloring with higher concentration.

Example 9 A decorative melamine laminate was prepared by a method similar to that of Example 7 except that the colorant of the composition set forth in Fig. 2 was dried and primed before being applied in powder form. The application of the dye was much simpler and could be carried out in a smoother manner than with liquid dyes. The aging resistance of the colored parts of the resulting laminate was the same as that of the laminate of Example 7. Exemplary 10 Screen printing of the combinations shown in Table 3 was performed with free-print ink on the surface of the cover enamel layer on the press plate, which was achieved by the same method. as in Example 7.

Table 3 §r Cloth mask size Pattern Free-printing ink 100 pm Stone grain texture Matt-made 2,250 pm modified piat-tfog natgjora After printing no. 1, the ink layer was dried by heating to 10 ° C. Thereafter, printing No. 2 was performed, after which firing took place to cause both ink layers to adhere to the cover enamel layer. The firing conditions corresponded to those of Example 7. In the surface of the enamel layer of the thus obtained press plate, the parts corresponding to the stone grain texture were mat and slightly protruding, while parts corresponding to the plate joints were mat 8Û04836 ~ 6 l0 15 ed 25 And protruded slightly higher than the stone grain texture portions. The approaches of the ink layer were rounded and glossy; Printing cloths with a mesh size of 74 μm were prepared with the positive patterns used in the prints, indicated above by 1 and 2. Using these printing cloths, the carpet surface of the enamel layer was dyed according to the following Table 4.

Table 4 is Cloth mask size Pattern Dye l '74 um Stone grain texture Light gray 2' 74 pm Modified plate joint Black The dye had the following composition: Table 5 Dye no. 1 (light gray) Melamine formaldehyde resin (S-260) 100 parts by weight Carbon black 2 parts by weight Titanium dioxide 23 parts by weight Titanium dioxide 23 Surfactant 2 parts by weight Thicker 2 parts by weight Dye No. 2 (black) Melamine formaldehyde resin (S-260) 100 parts by weight Carbon black 25 parts by weight water loo parts by weight Surfactant 2 parts by weight Thicker 2 parts by weight After drying the dyes, a decorative melamine laminate was prepared. The resulting decorative laminate of melamine formaldehyde resin was made matt and colored black in the plate joint parts and was even with fine matte recesses and colored gray in the plate surface parts. The decorative laminate as a whole had a particularly advantageous appearance and very much resembled a real flat surface.

Example 11 In the press plate of Example 7 and the dye ~ with the composition given in Table 6, a dye was applied to the mat surface of the press plate. A sheet of paper impregnated with dialyl phthalate resin was placed on plywood 4 mm thick and hot pressed at 130 ° C at a pressure of 10 kg / cm 2 for 15 minutes. Eabell 6 Dialyl phthalate resin prepolymer 93 parts by weight Dialyl phthalate resin monomer 7 parts by weight Pigment 25 parts by weight Solvent (Acetone: MIBK 1: 1) 100 parts by weight 10 The mold was easily opened without the use of any release film. The decorative laminate thus obtained had an appearance similar to the appearance of the decorative laminate of melamine formaldehyde resin according to Example 7, and the adhesion of the dye to the matte surface of the recesses was sufficiently strong.

Example 12.

A primer was applied to both surfaces on a steel plate with a thickness of 1.6 mm. Firing was performed in such a way that the coating became even on both sides of the steel plate. Then, cover enamel was applied to the two primers to create an enamel layer.

Firing was performed a second time in such a way that the cover enamel layer became an even, semi-gloss enamel layer.

The cover enamel consisted of 100 parts by weight of matting agent and '25 100 parts by weight of frit. It showed a mirror reflection of about 70%.

Using a 100 .mu.m printing ink and a free-printing ink to produce a completely matte enamel layer, a walnut-pattern was printed on one of the enamel layers, which was made of cover enamel. Firing was performed a third time, whereby a press plate was obtained, which had mat projecting parts about 5 μm thick.

The enamel layer of the press plate was then provided with a coating of charcoal ink. It was wiped with a felt cloth, leaving charcoal ink only on the matte surface of the protruding parts corresponding to the trachial parts of the pattern. The charcoal printing agent consisted of alkyd resin, melamine resin, colorant and solvent.

Thereafter, a decorative melamine laminate is made using a press plate and a titanium paper, printed with a walnut trachial pattern and impregnated with melamine formaldehyde resin. The laminate thus obtained had recessed trachial parts which were charcoal colored.

Its surface is very similar to a real walnut slice with open pores. * Example 13 A press plate was made in exactly the same manner as in Example 12 except that a printing cloth of mesh size of 250 μm was used to make protruding parts approximately 100 μm thick, corresponding to extracial parts. The press plate was provided with a coating of charcoal printing ink on an enamel layer. It was then wiped with a felt cloth, leaving behind charcoal ink only in the concave parts of the mat projecting parts, corresponding to the trachial parts of the pattern. The charcoal ink was identical to the ink of Example 13.

A decorative melamine laminate is obtained using the press plate and a titanium paper printed with an extraction pattern and impregnated with melamine formaldehyde resin. The laminate thus obtained had large, deepened trachial parts, which were charcoal colored and had a very stereographic appearance. The surface was very similar to oak veneer with the appearance of so-called "antique oak".

The advantages of the present invention will now be summarized. The decorative laminate according to the invention has the following advantages: (a) The surface of the decorative laminate has a soft gloss (luster), which is very similar to the surface of ceramic tiles, and has a three-dimensional pattern on the surface, corresponding to the smooth surface of the enamel layer and is achieved by firing the enamel layer of the press plate. The decorative laminate thus obtained has an external appearance which is very similar to natural stone or ceramics. A decorative laminate which resembles an enamel layer and which has a luster and a three-dimensional pattern similar to the luster and three-dimensional pattern of the enamel layer is obtained even if a single color dye is used. , (b) A decorative laminate with protruding parts and recesses forming a continuous sinusoidal curved surface can be provided. Since this decorative laminate has no sharp edges in the pattern, it is suitable as a decorative laminate, which resembles enamel or ceramic. The surface of the laminate also has a tendency not to collect dust, but if this were the case, it would be easy to clean. (c) A decorative laminate with shiny protruding parts and matte recesses can be provided. This type of decorative laminated sheet can be made by means of a metal press plate made by conventional etching or the like. This decorative laminate is suitable for tile patterns or enamel designs. (d) A decorative laminate having matte and colored recesses may be provided. This decorative laminate is suitable for wood fiber patterns with trachial parts or ceramic plate patterns.

The method of producing the decorative laminate according to the invention has the following advantages: (a) A release liner is not required in the manufacture of a decorative laminate because the release properties of the mold due to the enamel layer on the surface of the mold plate are very good. (b) The press plate with an enamel layer can be manufactured with ease without any complicated processes, such as etching and grinding, whereby the manufacture becomes cheap. (c) In the production of a decorative melamine laminate, a pressure of 50-120 kg / cm 2 and a temperature up to 140-160 ° C are required. Therefore, since the pressure plate used in the invention is fired at a temperature of 500-110 ° C, it can easily withstand the above-mentioned pressure life is therefore indefinitely long. (d) When an enamel layer is provided on both sides of the press plate, the enamel layer can be prevented from settling during its firing and during the manufacture of the decorative laminate. Furthermore, if a three-dimensional pattern is achieved on the enamel layers on both sides of the plate, molding of a decorative laminate can take place by means of both surfaces, so that the manufacturing efficiency is improved. (c) Since the enamel layer has better thermal conductivity than a conventional resin press plate, the manufacturing efficiency is improved. (f) Since the three-dimensional pattern of the enamel layer consists of smooth curves, dust tends not to accumulate thereon and the layer is easy to wipe off should this be the case. '

Claims (11)

10 15 20 25 30 8004836 ~~ b 31 PATENT REQUIREMENTS 1. A method of hot pressing a decorative laminate by means of a press plate, consisting of a metal substrate and a glass enamel layer thereon, characterized in that the glass enamel layer is provided by applying a glass-forming material to the substrate to form a water texture and burning the layer at a temperature exceeding the melting temperature of the glass, so that the resulting glass enamel layer obtains a surface structure with smooth curves formed by the melting of the glass. 2. A method according to claim 1, characterized in that the glass-forming material is a ground sludge, comprising water, a glass frit and a mill additive. 3. A method according to claim 1 or 2, characterized in that the surface texture has elevations and depressions in a repeated pattern. 4. A method according to claim 1 or 2, characterized in that the surface texture has elevations and depressions, the elevations having varying heights. 5. S. A method according to claim 3 or 4, characterized in that the elevations are smooth and the depressions are matted. 6. A method according to claim 5, characterized in that the elevations have even approaches. l 7. A method according to any one of claims 1-6, characterized in that the glass enamel layer is printed with an ink which contains glass frit and which is then fired. 8. A method according to claim 7, characterized in that the ink contains a matting agent and that ink is applied so that the elevations in the surface texture are matted by the ink thereon. 9. A method according to claim 8, characterized in that the printing ink contains a dye and that the glass enamel layer is printed only on the elevations. 10. A method according to claim 9, characterized in that the ink further comprises as a binder a resin which is the same as or compatible with the resin present in the decorative laminate, the compatible resin present in the ink, cures at a lower temperature than the resin present in the decorative laminate. 11. A method according to any one of claims 1-10, characterized in that an additional enamel layer is applied between the first-mentioned glass enamel layer and the substrate.