RU2449894C2 - Multilayer plate - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to multilayer plate. Proposed plate comprises inner layer including one or several layers of kraft paper, decorative layer of decorative paper sheet, particles with Mohs' hardness of 8, binding system containing one binding agent in hardened state. Note here that said binding system has inner layer and decorative layer. Note also that hardened binding layer is applied onto decorative layer with aforesaid particles. Mind that brilliance of multilayer plate makes 80 GE. Note also that multilayer plate surface formed by binding layer features decrease in brilliance after loading in brilliance decrease test GR₅₀₀ of not over 7%. Particles feature average grain size of 5-100 mcm. Loading multilayer plate with said particles, in terms of plate surface, makes 21-35 g/m². Note that registration of decreased in brilliance is performed in compliance with DIN 67530 at light incidence angle of 60°.

EFFECT: higher wear resistance and stability of brilliance.

8 cl, 5 ex, 1 dwg

Description

The present invention relates to a multilayer plate and a panel that includes such a multilayer plate.

Multilayer boards, also referred to as laminate boards or laminate, are used today in many areas for ordinary and decorative purposes. They find application, for example, in interior decoration for facing windows, stairs and floors, and in covering furniture in both private and industrial areas.

Multilayer boards usually consist of a certain number of different paper sheets that are impregnated with curable synthetic resins, stacked on top of each other and, when exposed to heat and high pressure, are pressed together with pressure plates (often also called press pads). The core of such multilayer plates is usually a system of several sheets of kraft paper, on which, as a rule, is a sheet of decorative paper provided with a pattern or paint. Finally, a usually transparent protective film (overlay = overlay) can be applied to a sheet of decorative paper. Laminated boards made in this way (high pressure laminates, HPLs = high pressure laminates) are sold, for example, under the trade name "Resopal".

Multilayer slabs are often processed into panels, for example floor slabs, which are used as flooring in internal or external areas of buildings. Floor slabs serve as a constant surface for walking and standing and are therefore subject to high mechanical stresses.

On this basis, multilayer slabs, when they are processed into floor slabs, must have high resistance to mechanical stress, in particular wear resistance. In the European standard EN 13329, Appendix E defines a test for determining the wear resistance of laminate floors and the classification of tested laminate floors by wear classes from AC1 (medium-wear-resistant in the case of home use) to AC5 (highly wear-resistant in the commercial field).

High wear resistance of the surfaces of multilayer plates or, accordingly, having such multilayer plates of laminate floors is achieved primarily due to the fact that corundum particles are introduced into the multilayer plates, which are inherently characterized by high hardness. Wear resistance can be controlled, in particular, by the size and quantity of the corundum particles used.

In order to increase the wear resistance of laminate surfaces, EP 0329154 proposes to glue a paper sheet impregnated with resin and coated with solid particles with a primer layer of the laminate. The paper sheet, at least on one side, must be provided with solid particles in an amount of from 2 to 20 g / m ² , preferably from 3 to 12 g / m ² . According to this publication, with solids greater than 20 g / m ² , an unacceptable whiteness may occur (appearance of a matte coating).

Another decisive criterion for the quality of multilayer boards along with wear resistance is also the degree of surface gloss. As a rule, the surface gloss desired by the user is largely determined by the type of hardened binder located on the surface of the multilayer plate. Further, for example, from EP 0826790 it is known that the degree of gloss of the surface of a multilayer plate also depends on the quality of the surface used to compress the multilayer plates of the pressure plate. Thus, with the help of a smooth (high-gloss) (mirror) pressure plate, multilayer plates with surfaces with a mirror (high) gloss can also be made.

It is true in the prior art that there is a problem that although multilayer boards that have a high gloss, by selecting a suitable binder that promotes gloss, or by using pressure plates with a high gloss surface can be produced without problems, but this gloss with regular mechanical loading of such multilayer boards fades. In the case of application in the field of floor coverings of this kind, rapid discoloration contributes to the impression of severe wear, which is not desirable for the user and thus unacceptable.

To increase the gloss stability of laminate surfaces, EP 0136777 proposes to supply the outer region of the laminate surface with mineral particles that have a size of 5 to 100 nm. Although the surface of a laminate made in this way has improved gloss stability, the surface due to the use of such relatively small particles does not impart high wear resistance.

EP 0219769 B1 describes a decorative laminate and a method for manufacturing such a laminate. The decorative sheet of the laminate is coated with granular abrasive material with greater hardness than the hardness of silica. The abrasive material is applied in an amount of 0.2-10 g / m ² , preferably 4-6 g / m ² . An applied amount in excess of 10 g per square meter may result in a dull surface appearance. The resistance of the laminate surface against scratching was checked by measuring the loss of gloss (tarnishing) after abrasive loading. The gloss loss after abrasion with 10 double passes when using an abrasive sheet of 3M Scotch Brite type 8A was 4%.

AT 40807 E describes a decorative laminate joined by heating and pressure, the outer surface of the laminate containing mineral particles that have a Mohs hardness of at least 5 and are contained in an amount in the range of 0.5-25 g / m ² . At higher concentrations of mineral particles, laminates often become dull and lose their luster. Loss of gloss after abrasion with 10 double passes when using an abrasive sheet made of Scotch Brite type 8A material was approximately 5%.

DE 103555180 A1 relates to a decorative laminate, a plate of a decorative laminate, as well as a method for manufacturing a decorative laminate. A decorative laminate consists of a decorative layer and a protective layer rigidly connected to the decorative layer, which consists of a mixture of at least one thermosetting resin, solid particles (Mohs hardness of at least 5) and at least one wax. The addition of wax, in particular during the manufacturing process, favorably affects the voltage of the tool. In addition, one preferred embodiment is described that does not contain any solid particles in the decorative strip or, respectively, the covering sheet. Through this, a better optical impression of the pattern can be achieved. No wear and abrasion tests were performed here.

EP 0875399 A2 concerns a decorative laminate with a wear-resistant surface coating. Particles of a solid material, such as corundum, are distributed in the wear (protective) layer. The wear layer contains a load of corundum 69 g / m ² . This is achieved through special additives in the resin matrix. But there is no data on the gloss and gloss gloss of laminates.

DE 197 10 619 A1 relates to melamine resin coated solid particles, wherein the Mohs hardness of the solid particles is at least 7. Further, the invention relates to aqueous impregnation solutions which contain these coated solid particles and other substances which are common in solutions that are suitable for the manufacture of protective and decorative films, and the protective and decorative films actually made with their help. But there is no data on the gloss and gloss gloss of laminates.

WO 2005/042644 A1 describes a decorative paper with sprinkled wear-resistant particles. The protective and decorative paper is preferably flattened and pressed so that the abrasion resistant particles form an intermediate layer. There is no data on the gloss and gloss stability of laminates.

DE 1629426 A describes wear-resistant, decorative laminated pressed materials, which are characterized in that the resin mass of the surface layer contains a finely divided material with a hardness of at least 9 on the Mohs hardness scale. But there is no data on the gloss and gloss gloss of laminates.

Thus, from the prior art, multilayer plates are known whose surfaces show increased wear resistance or increased gloss resistance.

However, until now multilayer plates whose surfaces had both excellent wear resistance and excellent gloss resistance could not be manufactured.

Therefore, the present invention is based on the task of providing a multilayer plate, the surface of which is characterized by excellent gloss stability and high wear resistance.

This problem is solved according to the first idea of the invention by means of a multilayer plate comprising an inner layer, a decorative layer, particles with a Mohs hardness of at least 8, a bonding system in which said inner layer and said decorative layer are provided and which forms an arranged on the decorative layer, a bonding layer that contains the particles, and (i) the surface of the multilayer plate formed by the bonding layer has a decrease in the degree of gloss after abrasion into the test GR ₅₀₀ to reduce gloss of at most 7%, wherein the initial degree of gloss is at least 80 GE, (ii) particles have an average grain size of 5-100 microns, and (iii) loading the multilayer plate particles, based on the surface multilayer slabs, is in the range of 21-35 g / m ² .

This problem is also solved according to one other idea of the invention by means of a multilayer plate containing an inner layer, a decorative layer, a protective layer (overlay layer), particles with a Mohs hardness of at least 8, a bonding system in which said inner layer is provided, said decorative layer and said protective layer and which forms a bonding layer located on the protective layer that contains said particles, wherein (i) the surface of the multilayer plate formed by the bonding layer has a decrease in GR _{500 of a} degree of gloss of at most 7%, with an initial degree of gloss of at least 80 GE, (ii) the particles have an average grain size in the range of 5-100 μm, and (iii) the loading of the multilayer plate by particles, in terms of the surface of the multilayer plate is in the range of 21-35 g / m ² .

In the inner layer of the multilayer board according to the invention, one or more sheets of kraft paper are contained.

The kraft paper used in the present invention is, according to DIN 6730, a paper which predominantly consists of kraft pulp, to which kraft pulp paper can be added, and which has high strength, in particular high tensile strength, and high stability. Kraft paper is typically made from at least 90 percent of fresh, preferably unbleached sulfate pulp (kraft pulp). Further, kraft paper along with cellulose still contains starch, alum and / or glue in order to achieve, for example, certain surface effects and increase strength. For the purposes of the present invention, kraft paper weighing 150-300 g / m ² , in particular 220-270 g / m ² , is particularly preferred. A preferred kraft paper is sodium kraft paper which is familiar to one skilled in the art of HPL.

The amount of kraft paper sheets used depends essentially on the desired thickness of the inner layer or, accordingly, the multilayer board. Preferably, the laminate according to the present invention contains from one to eight sheets, preferably 3-7 sheets, and in particular 4-6 sheets of kraft paper.

The weight of the kraft paper used according to the invention is not further limited by anything. This depends, in particular, on the number of kraft paper sheets used and thus on the desired thickness of the multilayer board. According to one preferred embodiment, the weight of the used kraft paper sheets is in the range of 125 to 250 g / m ² , preferably 140-230 g / m ² .

According to one preferred embodiment, the final thickness of the laminate according to the invention is in the range of 0.75 to 0.85 mm. In this case, it may be preferable if 4 sheets of kraft paper are used, which have a weight of 125 to 175 g / m ² , preferably 150 g / m ² . On the other hand, 3 kraft paper sheets that have a weight in the range of 200 to 240 g / m ² , preferably in the range of 215 to 240 g / m ^2, can also be used for this.

According to one other preferred embodiment, the final thickness of the laminate according to the invention is in the range from 0.95 to 1.05 mm, preferably 1.0 mm. In this case, it may be preferable if 5 sheets of kraft paper are used that have a weight of 125 to 175 g / m ² , preferably 150 g / m ² . On the other hand, 4 kraft paper sheets that have a weight in the range of 200 to 240 g / m ² , preferably in the range of 215 to 240 g / m ^2, can also be used for this.

According to yet another preferred embodiment, the final thickness of the laminate according to the invention is in the range of 1.15 to 1.25 mm, preferably 1.2 mm. In this case, it may be preferable if 6 sheets of kraft paper are used which have a weight of 125 to 175 g / m ² , preferably 150 g / m ² . On the other hand, 5 kraft paper sheets that have a weight in the range of 200 to 240 g / m ² , preferably in the range of 215 to 240 g / m ^2, can also be used for this.

On one side of the inner layer made of kraft paper of the multilayer plate according to the invention, a decorative layer is applied, which includes a sheet of decorative paper.

By means of this decorative paper layer, the multilayer board according to the invention obtains its appearance. In accordance with this, the decorative layer is called that layer deposited on the inner layer, the pattern of which can be visually differentiated by the observer.

As used herein, the term “decorative paper” refers to any material that is suitable for bonding to the inner layer underlying it and, if necessary, the protective layer lying above it and which can reproduce the decorative finish. A preferred decorative paper material is paper. True, in the same way, the term “decorative paper” can also cover films, such as polymer films, or plywood. "Plywood" is a wooden sheet, which, as a rule, has a thickness of from 0.1 to 3 mm and which can give the decorative layer the appearance of a tree, such as patterned wood.

Typically, the decorative finish is applied to the decorative layer through a printing process. So, for example, through phototechnical reproduction, any motive can be produced and applied to decorative paper by intaglio printing. Said motif may consist, for example, of a wooden, stone, ceramic, color and / or fancy pattern. In addition, the above motive can also be carried out by smearing decorative paper with one or more paints.

The specific gravity of the decorative paper used is further unlimited. Preferably, the specific gravity lies in the range from 40 to 120 g / m ² , more preferably in the range from 60 to 100 g / m ² , in particular 70-90 g / m ² .

Between the inner layer and the decorative layer, if necessary, other layers can be located, such as, for example, the underlying layer. This underlayer serves, for example, to prevent curvature of the multilayer board or to reduce the occurrence of electrostatic charges. Preferably, the underlying layer includes one or more sheets of kraft paper.

If the multilayer plate has a protective layer, then it preferably forms a coating layer for the multilayer plate according to the invention and is applied to the decorative layer. The protective layer includes one or more sheets of preferably fibrous material.

The specific gravity of the sheets used for the protective layer is additionally unlimited. Preferably, it lies in the range from 12 to 40 g / m ² , more preferably in the range from 20 to 35 g / m ² , and even more preferably in the range from 25 to 32 g / m ² .

The protective layer preferably has high resistance to chemical, thermal and mechanical effects. If a fibrous material is used to make the protection (overlay), this fibrous material preferably contains bleached plant fibers, in particular cellulose, for example α-cellulose. The protective material is preferably such as to ensure that the motif of the decorative paper layer under the protection is visible after being pressed into a decorative, multilayer composite material according to the invention. Therefore, the protection / protective layer preferably has a high degree of transparency.

The particles contained in the laminate according to the invention have a Mohs hardness of at least 8, preferably at least 8.5, and even more preferably at least 9.

Preferably, in the case of particles, we are talking about particles of corundum (alumina), silicon carbide, aluminum boride, boron carbide, or a mixture thereof. Particularly preferred are corundum particles, in particular particles of white electrocorundum. Corundum particles can be, for example, predominantly with sharp edges or cubic, and can be preferably predominantly cubic.

These particles may be surface-known in a manner known to those skilled in the art. For example, particles may be coated with silane compounds. However, in a preferred manner, said particles are uncovered.

Particles with a Mohs hardness of at least 8 preferably have a defined grain size distribution that is recorded according to FEPA standard 42-2: 2006. In this standard, among other things, d3 values, d94 values and D50 values are specified, the D50 value giving the average grain size of the particles. Moreover, the average grain size is called the grain size, in which 50 percent of the particles have a grain size less, and 50 percent of the particles have a grain size larger than the average grain size.

The average grain size D50 of the particles used with a Mohs hardness of at least 8 lies in the range from 5 to 100 μm, more preferably in the range from 5 to 75 μm, even more preferably in the range from 12 to 75 μm, in particular a range of 45 to 75 microns, for example 68 microns.

The maximum d3 value is preferably higher than the average particle size of the particles, for example, 1.4-2.2 times, more preferably 1.5-2.3 times, even more preferably 1.5-2.0 times, and in particular, 1.5-1.8 times the average particle size. For example, the maximum d3 value may lie in the range from 10 μm to 156 μm, more preferably in the range from 10 μm to 118 μm, even more preferably in the range from 23 μm to 118 μm, in particular in the range from 72 μm to 118 μm .

The minimum d94 value is preferably below the average particle grain value and is, for example, from 0.20 to 0.68, more preferably from 0.23 to 0.65, even more preferably from 0.34 to 0.65, and, in particular, from 0.60 to 0.65 times the average particle size of the particles. For example, the minimum d94 value may lie in the range from 1 μm to 65 μm, more preferably in the range from 1 μm to 50 μm, even more preferably in the range from 5 μm to 50 μm, and in particular in the range from 25 μm to 50 microns.

Particles that have an average grain size D50 in the range of 45 μm to 75 μm, preferably in the range of 63 μm to 73 μm, in particular 68 μm, may be preferred in accordance with the invention. The maximum d3 value may then lie in the range from 70 μm to 120 μm, more preferably in the range from 96 μm to 115 μm, and in particular 105 μm. The minimum d94 value in this case may preferably lie in the range from 28 μm to 49 μm, more preferably in the range from 40 μm to 48 μm, in particular 44 μm. Therefore, for example, particles of the ZWSK 220 type can be used, with the next number after the name “ZWSK” to indicate the grain size in the meshes.

True, particles that have an average grain size in the range of 42 microns to 50 microns, more preferably in the range of 45 microns to 50 microns, and in particular 47.5 microns, may also be preferred. In this case, the maximum d3 value may preferably lie in the range from 65 μm to 78 μm, more preferably in the range from 70 μm to 78 μm, and in particular 74 μm. The minimum d94 value in this case may lie in the range from 25 μm to 31 μm, more preferably from 28 μm to 31 μm, and in particular 30 μm. Therefore, for example, particles of the ZWSK 240 type can be used.

Particles that have an average grain size of particles in the range of 35 μm to 40 μm, more preferably in the range of 37 μm to 40 μm, and in particular 39.9 μm, may also be preferred. In this case, the maximum d3 value may preferably lie in the range of 56 μm to 65 μm, more preferably in the range of 60 μm to 64 μm, and in particular 64 μm. The minimum d94 value in this case may lie in the range from 20 μm to 26 μm, more preferably in the range from 22 μm to 26 μm, and in particular 26 μm. Therefore, particles of the ZWSK 280 type, for example, can be used.

Particles that have an average particle size in the range of 27.5 μm to 33.5 μm, more preferably in the range of 30 μm to 33 μm, and in particular 32.8 μm, may also be preferred according to another embodiment. In this case, the maximum d3 value may preferably lie in the range of 46 μm to 55 μm, more preferably in the range of 49 μm to 55 μm, and in particular 54 μm. The minimum d94 value in this case may lie in the range from 14.5 μm to 20 μm, more preferably in the range from 17 μm to 19.5 μm, and in particular 19.5 μm. Therefore, particles of the ZWSK 320 type, for example, can be used.

Particles that have an average particle size in the range of 21 μm to 27 μm, more preferably in the range of 24 μm to 27 μm, and in particular 26.7 μm, may also be preferred according to another embodiment. In this case, the maximum d3 value may preferably lie in the range from 37 μm to 47 μm, more preferably in the range from 42 μm to 47 μm, and in particular 46 μm. The minimum d94 value in this case may lie in the range from 9 μm to 15.5 μm, more preferably in the range from 12.5 μm to 15.0 μm, and in particular 14.5 μm. Therefore, for example, particles of the ZWSK 360 type can be used.

In addition, mixtures of the above types of corundum particles can also be used.

The above particle sizes are particularly preferred when the multilayer board according to the invention is to be used for flooring.

If the multilayer plate according to the invention finds application in other fields, in particular where wear-resistant surfaces are desired, such as for tables or work panels, the average particle size is preferably in the range from 12.5 μm to 28 μm, and especially preferably in the range of 17 to 27 microns. The maximum d3 value is preferably in the range from 24 μm to 48 μm, and particularly preferably in the range from 31 μm to 47 μm. The minimum d94 value is preferably in the range from 5 μm to 15.5 μm, and particularly preferably in the range from 7.5 μm to 15.5 μm.

Therefore, particles that have an average grain size of particles in the range of 21 μm to 27 μm, more preferably in the range of 24 μm to 27 μm, and in particular 26.7 μm, may be preferred. In this case, the maximum d3 value may preferably lie in the range from 37 μm to 47 μm, more preferably in the range from 42 μm to 47 μm, and in particular 46 μm. The minimum d94 value in this case may lie in the range from 9 μm to 15.5 μm, more preferably in the range from 12.5 μm to 15.0 μm, and in particular 14.5 μm. Therefore, for example, particles of the ZWSK 360 type can be used.

Particles that have an average particle size in the range of 16.3 μm to 22 μm, more preferably in the range of 17 μm to 22 μm, and in particular 21.4 μm, may also be preferred. In this case, the maximum d3 value may preferably lie in the range from 30 μm to 40 μm, more preferably in the range from 32 μm to 40 μm, and in particular 37 μm. The minimum d94 value in this case may lie in the range from 7 μm to 12 μm, more preferably in the range from 8 μm to 12.0 μm, and in particular 21 μm. Therefore, particles of the ZWSK 400 type, for example, can be used.

Particles that have an average particle size in the range of 11.8 μm to 17.5 μm, more preferably in the range of 12.5 μm to 17.5 μm, and in particular 17.14 μm, may also be preferred. In this case, the maximum d3 value may preferably lie in the range from 23 μm to 33 μm, more preferably in the range from 24 μm to 33 μm, and in particular 31 μm. The minimum d94 value in this case may lie in the range from 4 μm to 8.5 μm, more preferably in the range from 4.5 μm to 8.0 μm, and in particular 7.5 μm. Therefore, for example, particles of the ZWSK 500 type can be used.

The multilayer plate according to the invention has a binder system in which an inner layer and a decorative layer are provided and which forms a binder layer (binder layer) located on the decorative layer, which contains particles with a Mohs hardness of at least 8.

The binder system according to the invention comprises at least one, but preferably at least two different binders in a cured state. By means of this at least one cured binder, the individual kraft paper sheets are connected under each other, and the inner layer and the decorative layer formed from kraft paper sheets are connected to each other. In this case, a decorative layer is applied to the inner layer formed from kraft paper sheets. On the decorative layer, in turn, a cured adhesive layer is applied that contains particles with a Mohs hardness of at least 8.

According to one preferred embodiment, the binder, which in the cured state joins the kraft paper sheets underneath one another and the inner layer formed from the kraft paper sheets with the decorative layer, is a thermosetting resin (polymer). Preferred binders are liquid or liquefiable resins, which, alone or with reagents, such as fixatives or accelerators, are cured by polymerization or stepwise polymerization by means of crosslinking reactions in thermosets without removing volatile components. Phenolic resins are particularly preferred for this. Phenolic resins according to DIN 16916, Part 1 and ISO 10082 are defined as condensation products of phenols and aldehydes. Unsubstituted phenol and formaldehyde are the main raw materials for the manufacture of phenolic resins. For details on the chemistry of phenolic resins, reference should be made to the following literature: A.Gardziella, L.A. Pilato, A.Knop, "Phenolic Resins", Springer Verlag, Berlin, Heidelberg, New York, Tokio, 1999; A. Gardzielle, H. G. Haub, "Phenolharze": Kunststoff Handbuch, Band 10, "Duroplaste", S.12-40, Carl Hanser Verlag, München, Wien, 1988; P. Adolphs, E. Giebeler, P. Stäglich, "Houben-Weyl, Methoden der Organischen Chemie", Band E20, Teil 3, S. 1974-1810, 4. Auftrage, Georg Thieme Vertrag, Stuttgard. According to one completely particularly preferred embodiment, phenol-formaldehyde resin is used as a binder for kraft paper sheets.

A binder, which in the cured state connects the decorative layer to the inner layer and forms a binder layer that contains particles with a Mohs hardness of at least 8, is preferably also a thermoset resin. For the purposes of the present invention, the use of amino plastics has proven to be preferred in this case. Aminoplasts are a polycondensation product of carbonyl compounds, preferably aldehydes, such as formaldehyde, or ketones, and NH-containing compounds, such as urea, melamine, urethane, cyan or, respectively, cyanediamides, aromatic amines and sulfamides, which bind to each other according to the type of Mannich reaction and, when used, harden into thermosets. Preferred amino plastics are urea-formaldehyde resins, melamine resins, urethane resins, cyan or, respectively, cyandiamide resins, aniline formaldehyde resins and sulfamide resins. Especially preferred was the use of melamine-formaldehyde resins. By this is meant curable condensation products from melamine and formaldehyde. Further, melamine-urea-formaldehyde resins may also be preferred.

According to one other embodiment, the multilayer plate of the present invention includes a protective layer that is located on the decorative layer. In this embodiment, a bonding layer that contains particles with a Mohs hardness of at least 8 is formed not on the decorative layer, but on the protective layer. In this case, it is preferable if the binder, which in the cured state connects the protective layer to the decorative layer and forms a bonding layer that contains particles with a Mohs hardness of at least 8, is one of the above thermosetting resins, particularly preferably one of the above aminos, such as, for example, a melamine-formaldehyde resin or a melamine-urea-formaldehyde resin. Moreover, it is preferable if the same binder is used to connect the decorative layer to the inner layer, to connect the protective layer to the decorative layer and to form a bonding layer that contains particles with a Mohs hardness of at least 8, preferably one of the above thermosetting resins, particularly preferably one of the above amino plastics, such as, for example, melamine-formaldehyde resin or melamine-urea-formaldehyde resin.

If a base layer is provided between the inner layer and the decorative layer, then in this case, the binder, which optionally connects the base sheets one under the other, the inner layer with the base layer and the base layer with the decorative layer, is preferably one of the above thermosetting resins, particularly preferably one of the above aminos, such as melamine-formaldehyde resin or melamine-urea-formaldehyde resin.

It will be understood by those skilled in the art that, in particular, on the boundary surfaces of the individual layers, such as, for example, the boundary surface between the inner layer and the decorative layer, mixing of the binders used can take place, and the boundaries between the individual layers are set, at least not by the binder used , and primarily due to the most external, forming separate layers of sheets.

The loading of the binder layer contained in the binder system according to the invention of the binder layer with particles with a Mohs hardness of at least 8 is - in terms of the surface of the multilayer plate - in the range from 21 to 35 g / m ² , preferably in the range from 22 to 32 g / m ² and even more preferably in the range of 23 to 29 g / m ² . Surprisingly, it was found that despite this high load of a multilayer slab with particles with a Mohs hardness of at least 8, it does not lead to the expected vaule formation (whiteness, appearance of a matte coating) on the visible surface of the multilayer slab.

A multilayer plate according to the invention is obtained due to the fact that a structure is produced which contains kraft paper sheets, decorative paper sheets and, if necessary, a protective sheet, as well as particles and a suitable binder system, place this system between special pressure plates and compress, and binder the system is cured.

The term "binder system" according to the invention refers to a single suitable binder or a combination of suitable binders. By the term “suitable binders” are preferably meant the same binders that have been described above as preferred for joining the individual layers contained in the multilayer plate or, respectively, for joining the sheets forming these layers.

Although below we are talking about a sheet of decorative paper or, accordingly, a protective (overlay) sheet only in the singular, the specialist will understand that, depending on the desired property of the multilayer board, several sheets of decorative paper or, respectively, protective sheets can also be used. The structure of a multilayer plate or, accordingly, several sheets of decorative paper or, respectively, protective sheets contained therein, is taken for granted by a specialist from the following embodiments.

According to the invention, the particles described above with a Mohs hardness of at least 8 are applied to the (topmost) sheet of decorative paper or, if a protective layer is desired, to the (topmost) protective sheet. In this case, the deposition of particles is carried out constantly, at least on the outer side of the uppermost sheet of decorative paper or, if there is at least on the outer side of the uppermost protective sheet. As used herein, the “outer side of the sheet” means the same surface of the named sheet that is not in contact with any other sheet of the structure. As used herein, the term “topmost” in conjunction with the named sheet means the same sheet of the layer in question that is farthest removed from the sheets of inner paper.

Particle application can be carried out by one of the conventional methods in the prior art, such as, for example, a wet-on-wet method (i.e., coating without intermediate drying) (see, for example, EP 122396, EP 693030), a dry method raw "(see, for example, EP 1011969, EP 837771, US 4940503) or the method of" dry by raw ". In the case of the wet-wet method, a suspension, which along with the particles mentioned above contains a suitable binder or water, is applied to the outer side of the topmost sheet of decorative paper impregnated with a suitable binder or, respectively, a protective sheet. In the case of the "dry on wet" method, the particles in the dry state without adding binders are applied to the outer side of the uppermost, binder-impregnated sheet of decorative paper or, respectively, a protective sheet. In the case of the wet-dry method, the suspension, which along with the particles also contains a suitable binder, is applied to the outer side of the uppermost, dry, not impregnated sheet of decorative paper or, respectively, a protective sheet.

The mass of the particles to be applied with a Mohs hardness of at least 8 is determined according to the desired load of the multilayer plate with these particles and is therefore 21-35 g / m ² , preferably 22-32 g / m ² , and even more preferably 23- 29 g / m ² , calculated on the surface of the multilayer plate.

Coated with said particles with a Mohs hardness of at least 8 and impregnated with a suitable binder, decorative sheets can be used directly for the manufacture of the above structures. However, the decorative sheets coated with said particles can also be dried first to obtain the so-called prepreg.

For the manufacture of said structure, individual sheets, preferably all sheets of different layers, are preferably impregnated with a suitable binder.

According to one preferred embodiment, said structure includes several sheets of kraft paper, preferably from three to six sheets of kraft paper. On the topmost sheet of kraft paper is a sheet of decorative paper. Particles with hardness on the Mohs scale of at least 8 can be deposited on this sheet of decorative paper, as described above. If a protective (overlay) layer is provided, then the particles are not deposited on a sheet of decorative paper, but on this protective (overlay) ) sheet. In this case, the particle-coated protective sheet is located on a sheet of decorative paper.

According to another preferred embodiment, in which a protective sheet is not provided, a decorative paper sheet superimposed on the uppermost kraft paper sheet is a prepreg of decorative paper, a suitable binder and particles located on the surface of the decorative paper with a Mohs hardness of at least , 8.

According to yet another preferred embodiment, in which a protective layer is provided that is applied to the kraft paper cover sheets, the decorative paper sheet is a prepreg of a protective sheet, a suitable binder and particles located on the surface of the protective sheet with a Mohs hardness of at least least 8.

According to yet another preferred embodiment, for the structure for manufacturing the multilayer board according to the invention, which comprises a protective layer, the protective sheet is first pre-impregnated with a melamine-formaldehyde resin. For this pre-impregnation, preferably 40-60 weight percent is used, particularly preferably 50-55 weight percent of the amount of a binder provided for impregnating the protective sheet, preferably a melamine-formaldehyde resin. Then a suspension that contains particles to be applied with a Mohs hardness of at least 8 and the remaining amount provided for impregnation of the protective sheet of melamine-formaldehyde resin (i.e. preferably 60-40 weight percent, particularly preferably 50-45 weight percent provided for by impregnating the protective sheet, an amount of a binder, preferably a melamine-formaldehyde resin) is applied to the protective sheet. Such a protective sheet coated with said particles is so superimposed on a decorative sheet impregnated with melamine-formaldehyde resin that said particles with a Mohs hardness of at least 8 are on the outside of the protective sheet, that is, in accordance with this, are not in contact with the decorative sheet by sheet. Then, the corresponding structure of the decorative sheet, protective sheet and particles is applied to the uppermost of the kraft paper sheets impregnated with a suitable binder, preferably phenol-formaldehyde resin, so that the decorative sheet is in contact with the kraft paper sheet.

In accordance with the invention, it is essential that the particles are located on the outer side of the uppermost decorative sheet or, accordingly, the uppermost protective sheet.

According to one other preferred embodiment, the kraft paper sheets present in the structure are preferably impregnated with a phenol-formaldehyde resin. The binder content in the impregnated kraft paper sheet is preferably in the range of 25 to 40 weight percent, more preferably in the range of 28 to 36 weight percent, and even more preferably in the range of 34 to 34 weight percent. The decorative paper sheet present in this structure is preferably impregnated with a melamine-formaldehyde resin or a melamine-urea-formaldehyde resin. The content of the binder in the impregnated decorative sheet depends, inter alia, on the motif of the decorative sheet. In the case of a one-color decor, the content of the binder in the impregnated decorative sheet is preferably in the range from 35 to 65 weight percent, more preferably in the range from 42 to 60 weight percent, and even more preferably in the range from 48 to 55 weight percent. In the case of multicolor, created by means of a pattern or otherwise printed decorative motifs, the content of the binder in the impregnated decorative sheet preferably lies in the range from 35 to 65 weight percent, even more preferably in the range from 37 to 50 weight percent, and even more preferably in the range from 40 to 45 weight percent. The binder content of the protective sheet, if necessary in the structure, is preferably in the range of 60 to 90 weight percent, more preferably in the range of 65 to 86 weight percent, and even more preferably in the range of 70 to 83 weight percent.

After that, the prepared (impregnated) according to the invention structure is inserted between two pressure plates and pressed. For pressing, pressure plates are preferably used with a smooth, mirror and wear-resistant surface that is coated with titanium diboride, zirconium diboride, hafnium diboride, molybdenum diboride, tantalum diboride, tungsten diboride or vanadium diboride. Coating with such diborides is preferably carried out in a magnetron sputter coating system and preferably has a Vickers hardness of at least 2000. The pressure plates which are disclosed in EP 0826790 are particularly suitable.

The compression of the structure is preferably carried out at a temperature in the range from 110 to 140 ° C., particularly preferably in the range from 120 ° C. to 150 ° C. and at an elevated pressure of preferably at least 4 N / mm ² , particularly preferably at least at least 5 N / mm ² . The pressing time is preferably in the range of 40 to 90 minutes, particularly preferably in the range of 50 to 80 minutes.

The simultaneous use of heat and high pressure allows the flow and subsequent curing of the binder.

The product obtained after compression of said structure and curing of the resin is then referred to as a multilayer board.

The finished multilayer plate, depending on the selected structure, has various thicknesses. Typical thicknesses are in the range of 0.5 mm to 2 mm, preferably in the range of 0.6 mm to 1.5 mm, and particularly preferably in the range of 0.8 to 1.2 mm. However, it is also possible to produce multilayer plates with much greater thicknesses, such as, for example, in the range from 2 mm to 20 mm.

If the multilayer plate contains a protective layer, then its thickness preferably lies in the range from 80 to 120 μm, particularly preferably in the range from 80 to 110 μm. In this case, the thickness of the protective layer is understood as the distance between the outer side of the particle containing Moos hardness of at least 8 bonding layer facing the decorative layer and the sheet of decorative paper in contact with the protective layer. The thickness of the decorative layer is preferably in the range of 65 to 140 microns, particularly preferably in the range of 65 to 80 microns. In this case, the thickness of the decorative layer is understood as the distance between the outer side of the decorative paper sheet in contact with the protective layer and the outer side of the inner layer in contact with the decorative layer of kraft paper sheet. The thickness of the inner layer can vary greatly depending on the desired thickness of the multilayer plate and preferably lies in the range from 250 to 1900 μm, particularly preferably in the range from 500 to 1500 μm.

If the multilayer plate does not contain a protective layer, then the thickness of the decorative layer also preferably lies in the range from 65 to 140 microns, particularly preferably in the range from 80 to 140 microns. In this case, the thickness of the decorative layer is defined as the distance between the outer side of the containing particle with a Mohs hardness of at least 8 binder layer and the outer side of the inner layer in contact with the decorative layer that is in contact with the decorative layer. The thickness of the inner layer, regardless of the presence of the protective layer, lies, for example, in the range from 250 to 1900 μm, particularly preferably in the range from 500 to 1500 μm.

The final weight of the laminate according to the invention depends on several factors, such as the thickness of the laminate, the weight of the components used and the number of sheets used. Preferably, the weight of the multilayer plate lies in the range from 1.2 to 1.6 kg per m ^{2 of the} surface of the multilayer plate (kg / m ² ), particularly preferably in the range from 1.3 to 1.5 kg / m ² , for example 1.4 kg / m ² .

The surface of the multilayer plate formed by the bonding layer, which contains particles with a Mohs hardness of at least 8, has a decrease in the GR _X or GRS _X degree of gloss after loading by abrasion in the test to reduce the degree of gloss, which does not exceed the maximum value.

According to the invention, in order to determine a reduction in gloss, a gloss is measured before and after a predetermined abrasion loading. A test for determining gloss reduction is referred to in accordance with the invention as a gloss reduction test.

The determination of the degree of gloss is carried out in the framework of the invention invariably according to DIN 67530 at an angle of incidence of light 60 °. At the same time, the obtained values of the reflectometer at 60 ° incidence of light (measuring geometry) are correlated with a black, polished glass standard with a given refractive index. For this standard, the measured value is calibrated to 100 gloss units (100 GE).

According to the definition, the initial degree of gloss means the degree of gloss of the surface of a multilayer plate, which is obtained before loading by abrasion during the test to reduce the degree of gloss. This initial gloss is at least 80 GE, preferably at least 85 GE, and particularly preferably 90 GE.

Abrasion loading as part of the gloss reduction test is carried out as follows:

The slide, on the lower side of which a predetermined abrasive means is fixed, with uniform linear movement with a weight load of 0.5 N / cm ^{2 are} sent along a section of 220 mm of the surface of the multilayer plate. Then the linear motion is repeated in the direction of motion, which is opposite to the first direction of motion. By definition, “double stroke” means a completely completed movement in one direction and in the direction opposite to that direction, so that the slides of the same section twice during a double stroke (movement back and forth). In the gloss test, abrasion loading is performed by performing a predetermined number of double strokes, the region of the area on the surface of the multilayer plate being in contact with the abrasive is determined by the first double stroke and remains unchanged during the entire loading.

By definition, to obtain a decrease in GR _X (or GRS _X , respectively) of the gloss after abrasion loading during the gloss test, the difference between the initial gloss and gloss after the abrasion loading during the gloss reduction test from X double strokes is determined and the ratio between this difference and the initial degree of gloss is calculated. The resulting value is multiplied by 100 percent and is referred to as the reduction in gloss after abrasion loading during the gloss reduction test, GR _X (or GRS _X , respectively). In accordance with this, the following formula can be used to calculate this value:

Decrease in gloss, GR _X (or GRS _X , respectively), [in%] = {[(initial gloss) - (gloss after abrasion loading × number of double strokes)] / [(initial gloss)]} × one hundred%.

According to the invention, abrasion loading during a gloss test to determine the loss of GR _X degree occurs due to the use of type P1200 sanding paper as an abrasive. In this case, the parameter "P1200" refers to the grit characteristics determined according to the international standard ISO 6344-1: 1999. According to this, corundum particles have a d _s0 value of a maximum of 58 μm, a d _s3 value of a maximum of 29.7 μm, an average grain size (d _s50 value) of 15.3 ± 1.0 μm and a d _{s95 value of a} minimum of 10.2 μm measured by a US sedimentometer according to ISO 8486-2. The corundum content in the used sanding paper is 24.3 g / m ² . The weight of the used sanding paper is 250 g / m ² .

In accordance with the invention, 500 double strokes are performed to determine the loss of GR _X gloss after abrasion loading during the gloss reduction test. Accordingly, the obtained gloss reduction value is referred to as “GR ₅₀₀ ”.

The surface of the multilayer plate formed by the bonding layer, which contains particles with a Mohs hardness of at least 8, has a GR ₅₀₀ reduction in gloss after loading by abrasion during a gloss reduction test of at most 7%, preferably at most 6%, more preferably at most 5%, and even more preferably at most 4%.

True, it is also possible to reduce the GR _X degree of gloss after loading by abrasion during the test to reduce the degree of gloss measure with a different number of double strokes. So, for example, 250 double strokes can also be carried out for abrasion loading. The thus determined gloss reduction value is called GR ₂₅₀ .

The bonded layer surface of the multilayer plate, which contains particles with a Mohs hardness of at least 8, preferably has a reduction in gloss after abrasion loading during a gloss reduction test with 250 double strokes, GR ₂₅₀ , at most 5%, preferably at most 4%, even more preferably at most 3% and, in particular, at most 2%.

According to one other embodiment, the grinding medium used for abrasion loading during the gloss test is also a steel fiber. In the case of steel fiber, we are talking about steel chips with a degree of grinding 1, consisting of rectangular chips from a material that, according to DIN 17145, corresponds to Type 11Mn4Si with material number 1.0492.

If steel fiber is used as the grinding medium for abrasion loading during the test to reduce the degree of gloss, then the reduction in gloss is expressed as GRS _X , and the index “X” following the abbreviation “GRS”, in turn, refers to the number of abrasion loads double moves.

If steel fiber is used as a grinding medium for abrasion loading during a gloss test, abrasion loading is preferably carried out by performing 500 double strokes. Accordingly, the value obtained to reduce the degree of gloss is denoted as GRS ₅₀₀ .

Preferably, the surface formed by the bonding layer, which contains particles with a Mohs hardness of at least 8, has a GRS ₅₀₀ decrease in gloss after abrasion loading during the test to reduce gloss with steel fiber at most 10%, preferably at most 7 %, more preferably at most 5%, even more preferably at most 3% and, in particular, at most 1%.

According to one other preferred embodiment, the abrasion loading during the test to reduce the degree of gloss when using steel fiber is carried out when exposed to 250 double strokes. The corresponding value obtained to reduce the degree of gloss is called as GRS ₂₅₀ .

Preferably, the surface formed by the bonding layer, which contains particles with a Mohs hardness of at least 8, has a GRS reduction of ₂₅₀ degrees of gloss after loading by abrasion during the test to reduce the degree of gloss by means of steel fiber at most 5%, preferably at most 4 %, more preferably at most 3%, even more preferably at most 2% and, in particular, at most 1%.

According to one preferred embodiment, the bonded layer surface of the multilayer plate, which contains particles with a Mohs hardness of at least 8, has wear resistance according to DIN EN 13329, Appendix E, which allows the multilayer plate to be classified according to the wear class AC3, preferably AC4 and in particular, AC5.

Accordingly, the wear resistance according to DIN EN 13329, Appendix E, the test is preferably at an IP value (IP = Initial Point; starting point) of at least 5000 revolutions, particularly preferably at least 5700 revolutions, still more preferably at least 6500 rpm. The preferred range for IP ranges from 5,000 to 10,000 rpm, particularly preferably at 6,000 to 9,500 rpm, and most preferably from 6,500 to 9,000 rpm. According to this test, the wear characteristic of a multilayer plate is determined. To do this, the test part of the multilayer plate rotates between two wear wheels, which are equipped with sandpaper. Through abrasion, the wear resistance of a multilayer plate is measured. The speed of rotation, type and replacement of sanding paper are precisely pre-described. The unit of measurement is the IP value, that is, the number of revolutions after which the wear phenomenon occurs. To determine the wear resistance, sandpaper specified in DIN EN 13329 is used, which is characterized, in particular, by a density of 70 g / m ² to 100 g / m ² , 180 grit aluminum oxide with a grain size that passes through a sieve with holes of 100 μm is freely covered but not through 63 μm holes.

According to another preferred embodiment, the bonded layer surface of the multilayer plate, which contains particles with a Mohs hardness of at least 8, has impact resistance according to EN 13329, Appendix F, which allows classifying the multilayer plate according to class IC2, preferably IC3. When carrying out the test for shock loading using a large ball (diameter = 42.8 mm; mass = 324 g), the drop height is preferably at least 1300 mm, more preferably at least 1500 mm and, in particular at least 1700 mm. When carrying out the impact test defined in this standard using a small ball, the impact resistance is preferably in the range of 15 to 25 N, more preferably in the range of 17 to 23 N, and in particular in the range of 18 to 22 N.

In the case of one other aspect, the invention relates to a panel that includes a substrate and a laminate plate according to the invention adhering to the substrate. The preferred way in the case of the panel we are talking about the base plate (floor panel). Further, the panel may also be another panel, such as a countertop.

Preferred substrates are chipboards, plywood boards, load-bearing boards (optionally coated with laminate), high-density fiberboards, medium-density fiberboards, hardboard, wood joinery, glued panels, solid wood, honeycomb, foam, metal, metal sheets, mineral substrates, natural or artificial stone, ceramic tiles and gypsum boards. The substrates can be coated with a suitable binder, such as melamine resin, or left uncoated. Multilayer boards can be applied both to liquid-absorbing (moisture-absorbing) substrates, such as uncoated wood-based panels and various woods, and to non-liquid-absorbing (non-moisture-absorbing) substrates, such as metal, ceramic, glass, coated wood, coated chipboards, etc.

Methods and means for rigidly bonding a multilayer plate and a substrate are known in the art. For example, a rigid connection of a multilayer plate and a substrate can be carried out by gluing or by using connecting elements known from the prior art. The connection of the multilayer plate with the substrate material is such that the surface of the multilayer plate, which is opposite the surface containing particles with a hardness on the Mohs scale of at least 8 surfaces, is in contact with the surface of the substrate. Therefore, in a preferred manner in the panel, the surface of the substrate and the surface formed by the inner layer of the multilayer plate are in contact with each other.

In addition, the panel has other functional materials known in the art. For example, fire protection materials, for radiation shielding, for sound insulation, for stabilization and for protection against moisture penetration should be called. Preferred functional materials include anti-stretch (stabilization) material and / or impact sound insulation material, which is preferably used in base (floor) slabs.

The thickness of the panel is not further limited. It is preferably in the range of 9 to 15 mm, particularly preferably in the range of 10 to 14 mm, and particularly preferably in the range of 11 to 13 mm. The thickness of the panel laminate available in the panel, as described above, can preferably be in the range of 0.5 to 2 mm, particularly preferably in the range of 0.6 to 1.5 mm, and particularly preferably in the range of 0.8 to 1.2 mm The thickness of the substrate, for example a high-density fiberboard, is preferably in the range of 5 to 13 mm, particularly preferably in the range of 8 to 10 mm, particularly preferably in the range of 9.0 to 9.6 mm. If necessary, a material for counteracting stretching and / or a material for isolation from impact noise is preferably provided in a thickness in the range of 0.5 to 3 mm, particularly preferably in the range of 1 to 2 mm.

The final weight of the panel is not particularly limited. Preferably, it is in the range of 8 to 13 kg per m ² of panel surface (kg / m ² ), particularly preferably in the range of 9 to 12 kg / m ^2, and particularly preferably in the range of 10 to 11 kg / m ² .

The panel according to the invention is processed in a manner known per se to a person skilled in the art. If the panel is a base plate, then this plate is provided with a tongue-and-groove structure in order to make a plane connection of several such base plates for the manufacture of lined boards or tile structures.

The present invention is illustrated by the following examples, which, however, should not be construed as limiting:

Examples

An example implementation 1.1: the manufacture of corundum-containing melamine resin mixture.

820 g of a 56% aqueous solution of melamine resin impregnation (including hardener, wetting and separating agents) was mixed with 180 g

macroelectrocorundum (type ZWSK 220; average grain size 68 microns).

An implementation example 1.2: the manufacture of impregnated and coated on one side of the protective paper.

Protective paper consisting of α-cellulose with a density of 30 g / m ^{2 was} impregnated until saturated with melamine resin. Excess resin was removed on the surface between two polishing steel rolls. The melamine resin applied to the protective paper was dried for 2 hours at room temperature to obtain a pre-impregnated protective paper.

Then 135 g / m ² corundum-containing melamine resin mixture from Example 1.1 was evenly distributed on one side of the pre-impregnated protective paper. Coated with corundum particles, the protective paper was dried in an oven with air recirculation for 4 minutes at 125 ° C.

Example 1.3: production of a multilayer board according to the invention.

For the manufacture of a multilayer board according to the invention, a structure suitable for compression by two press plates was first produced.

For this, four sheets of kraft paper, which was impregnated with phenolic resin, were placed on both sides of a 30 μm thick polypropylene separation film sheet. A sheet of decorative paper was applied to the topmost sheet of kraft paper, and a sheet of protective (overlay) paper made in Example 1.3 and coated with corundum particles was applied to a sheet of decorative paper. The protective paper was laid on a decorative sheet so that the surface of the protective paper having corundum particles was not in contact with the kraft paper sheet, but was oriented outward. A similar kind of structure is presented in diagram 1.

Scheme 1: structure for the manufacture of a multilayer board according to the invention

Titanium boride hard coated press plate

1 Protective paper from example 3

1 Decorative paper

4 sheets of kraft paper

1 sheet of PP separation film

4 sheets of kraft paper

1 Decorative paper

1 Protective paper from example 3

Titanium boride hard coated press plate

A similar kind of prepared structure was introduced between two press plates with smooth titanium boride coated in a system for magnetron sputter coating, mirror surfaces, pressed at a pressure of 10 N / mm ² and a maximum temperature of 135 ° C for 35 minutes and then cooled at room temperature .

The resulting multilayer plate shows high gloss and high transparency and has no traces of corundum coating and no formation of turbidity (opaque coating).

Measurement of the wear resistance of the surface of the multilayer plate formed by the bonding layer located on the protective (overlay) layer, carried out in accordance with DIN EN 13329, Appendix E, gave an IP value of 8100 revolutions.

Comparative Example 1

For comparison purposes, another multilayer plate was made which does not fall within the scope of the claimed invention.

For this purpose, a structure suitable for compression by two press plates was also initially produced. For this, four sheets of kraft paper that were impregnated with phenolic resin were laid on both sides of a 30 μm thick polypropylene separation film sheet. A sheet of decorative paper was applied to the topmost sheet of kraft paper, and a sheet of protective paper of the Mead-822 type (according to US 3798111) was applied to a sheet of decorative paper. In this protective paper, corundum particles are not distributed on one or, accordingly, several surfaces of α-cellulose paper, but are distributed in a fibrous layer.

A similar kind of prepared structure was introduced between two press plates with smooth titanium boride coated in a system for magnetron sputter coating, mirror surfaces, pressed at a pressure of 10 N / mm ² and a maximum temperature of 135 ° C for 35 minutes and then cooled at room temperature .

Reference Example 2

For the manufacture of another multilayer plate for comparison purposes, which does not fall within the scope of the claimed invention, a structure suitable for compression by two press plates was also first produced.

For this, four sheets of kraft paper that were impregnated with phenolic resin were laid on both sides of a 30 μm thick polypropylene separation film sheet. A sheet of decorative paper was applied to the topmost sheet of kraft paper, and a sheet of protective paper that was not covered with corundum particles was applied to a sheet of decorative paper.

A similar kind of prepared structure was introduced between two press plates with smooth titanium boride coated in a system for magnetron sputter coating, mirror surfaces, pressed at a pressure of 10 N / mm ² and a maximum temperature of 135 ° C for 35 minutes and then cooled at room temperature .

results

The surface formed by the bonding layer located on the protective layer of the laminate obtained in the exemplary embodiment and in comparative examples 1 and 2 was subjected to abrasion loading during the test to reduce gloss by means of abrasive paper. After a given number of double strokes, the degree of gloss was measured at a light incidence angle of 60 ° according to DIN 67530. The values obtained are presented in Table 1:

Table 1
Gloss at 60 ° after a given number of double strokes Number of Double Strokes The degree of gloss in GE: Example implementation GE gloss: Comparative Example 1 The degree of gloss in GE: Comparative example 2 0 109,2 103.6 115.5 fifty 110,4 90.5 63,2 one hundred 109.3 92.8 63,2 250 107.5 93.3 69.3 500 105,2 93.8 64.6

From the obtained values, the initial gloss level was determined, as well as the decrease in GR ₂₅₀ and GR ₅₀₀ gloss level (see Table 2).

table 2
Initial gloss and GR reduction ₂₅₀  and GR ₅₀₀  gloss during the test to reduce gloss after loading by abrasion using sanding paper Number of Double Strokes Implementation example Comparative Example 1 Reference Example 2 Initial Gloss [GE] 109,2 103.6 115.5 GR ₂₅₀ 1.6% 9.9% 40.0% GR ₅₀₀ 3,7% 9.5% 44.1%

Further, the surface formed by the bonding layer located on the protective layer, the surface of the multilayer plates obtained in the embodiment and in comparative examples 1 and 2 was subjected to abrasion loading during testing for abrasion using steel fiber. After a given number of double strokes, the degree of gloss was measured at a light incidence angle of 60 ° according to DIN 67530. The values obtained are presented in Table 3:

Table 3
Gloss at 60 ° after a given number of double strokes Number of Double Strokes The degree of gloss in GE: Example implementation GE gloss: Comparative Example 1 The degree of gloss in GE: Comparative example 2 0 114.2 102.8 118.2 fifty 114.6 99,2 115.7 one hundred 114.2 92.5 111.9 250 114.2 89.9 101.3 500 114.3 80.5 88.6

From the obtained values, the initial degree of gloss was determined, as well as the decrease in GR ₂₅₀ and GR _{500 of the} degree of gloss (see Table 4).

Table 4
Initial gloss and GRS reduction ₂₅₀  and GRS ₅₀₀  gloss during a test to reduce gloss after abrasion loading with steel fiber Number of Double Strokes Implementation example Comparative Example 1 Reference Example 2 Initial Gloss [GE] 114.2 102.8 118.2 GR ₂₅₀ 0,0% 12.5% 14.3% GR ₅₀₀ 0,0% 21.7% 25.0%

Although numerous measures are known from the prior art to increase the wear resistance and gloss gloss of the surface of multilayer plates, none of these measures led to a laminated sandwich with a surface that has both excellent wear resistance and excellent gloss resistance.

Comparative experience in relation to EP 0219769 B1 and AT 40807 E

EP 0 219 768 B1 and AT 40 807 E investigated the resistance of the laminate surface to scratching. The gloss loss of the laminate surface was measured after loading by abrasion in two places. Abrasion loading was carried out by abrasion with 10 double strokes using a crockmeter (Crockmeter = abrasion measuring device) using an abrasive sheet of 3M Scotch Brite type 8A. Studies have shown a brightness loss of 4% and, accordingly, 5%.

Next, experiments were carried out with respect to reducing the gloss level of the multilayer plate according to the invention under the experimental conditions, as described in EP 0219769 B1 and, accordingly, AT 40807 E.

Table 5
Gloss reduction according to the invention of the multilayer board during the gloss test according to EP 0219769 B1 and AT 40807 E by abrasion loading with 10 double strokes using an abrasive sheet of 3M Scotch Brite type 8A Gloss Degree Sample 1 Sample 2 Sample 3 10 double moves 1.8% 1.3% 1.5%

The resulting loss of gloss according to the invention of the multilayer board after the test according to EP 0219769 B1 and, accordingly, AI 40807 E is 1.5%.

The multilayer plate according to the invention has a very slight loss of gloss of only 1.5%, and thus a significantly lower gloss reduction than the multilayer plate disclosed in EP 0219769 B1 or, respectively, in AT 40807 E.

Outstanding properties are achieved in accordance with the invention, inter alia, by selecting particles with a Mohs hardness of at least 8, due to the number of particles with a Mohs hardness of at least 8, due to the special arrangement of particles with a hardness of Mohs scale of at least 8 on the surface of a multilayer plate and due to the choice of press plates used for pressing. In particular, because of this, the above is worthy of attention, since partly opposite measures were proposed in the prior art to achieve such properties.

Claims (8)

1. A multilayer plate including an inner layer containing one or more sheets of kraft paper; a decorative layer including a sheet of decorative paper; particles with a Mohs hardness of at least 8; a binder system comprising at least one binder in a cured state, wherein the binder system has an inner layer and a decorative layer, and a cured binder layer is applied to the decorative layer, which contains said particles with a Mohs hardness of at least , 8, wherein the gloss of the multilayer plate is at least 80 GE, and the surface of the multilayer plate formed by the bonding layer has a decrease in the degree of gloss after abrasion loading during the mind test a decrease in GR _{500 of a} degree of gloss of at most 7%; said particles have an average grain size in the range of 5-100 microns; the loading of the multilayer plate by said particles, in terms of the surface of the multilayer plate, is in the range of 21-35 g / m ² , and the degree of gloss is recorded invariably in accordance with DIN 67530 at a light incidence angle of 60 °. 2. A multilayer plate including an inner layer containing one or more sheets of kraft paper; a decorative layer including a sheet of decorative paper; a protective layer comprising one or more sheets of preferably fibrous material; particles with a Mohs hardness of at least 8; a binder system containing at least one binder in a cured state, wherein the binder system is provided with an inner layer, a decorative layer and a protective layer, wherein a cured binder material containing said particles with a Mohs hardness is applied to the protective layer at least 8, and the degree of gloss of the multilayer plate is at least 80 GE, and the surface formed by the bonding layer of the multilayer plate has a decrease in the degree of gloss after loading by abrasion in cold e test decrease GR ₅₀₀ degree gloss of at most 7%; said particles have an average grain size in the range of 5-100 microns; the loading of the multilayer plate by said particles, in terms of the surface of the multilayer plate, is in the range of 21-35 g / m ² , and the degree of gloss is recorded invariably in accordance with DIN 67530 at a light incidence angle of 60 °. 3. A multilayer plate according to claim 1 or 2, wherein the surface of the multilayer plate formed by means of a bonding layer has wear resistance according to DIN EN 13329, Appendix E, expressed as an IP value of at least 5000 revolutions. 4. A multilayer plate according to claim 1 or 2, wherein said particles with a Mohs hardness of at least 8 are corundum particles. 5. A multilayer plate according to claim 4, wherein the average grain size of the corundum particles is in the range of 45-75 microns. 6. The multilayer plate according to claim 1 or 2, wherein the loading of the multilayer plate by said particles, in terms of the surface of the multilayer plate, is in the range of 23-29 g / m ² . 7. A panel including a multilayer plate according to one of claims 1 to 6. 8. The panel according to claim 7 in the form of a base plate.