WO1999001296A1

WO1999001296A1 - Decorated laminate material and method for its production

Info

Publication number: WO1999001296A1
Application number: PCT/AT1998/000162
Authority: WO
Inventors: Werner Bechtold
Original assignee: M. Kaindl
Priority date: 1997-07-02
Filing date: 1998-07-01
Publication date: 1999-01-14
Also published as: AU8091398A; ATA113497A

Abstract

The invention relates to a decorated laminate material having a ground substrate made of a wood-based material, such as wood fiber boards, and a coating made of paper impregnated with a hardened resin. This coating is bound to the ground substrate on the side that is meant to be seen. The material is characterized in that just one paper layer is bound to the visible side of the substrate. This paper layer is impregnated with at least one substantially hardened thermosetting resin, as well as having a printed decoration and a pigment filling of 0-25 % in relation to the total mass of the paper. Said paper layer is made of translucent or transparent paper and the colouring and/or the printed decoration is underlaid with the visual elements, structure and/or texture of the substrate used.

Description

Decorative laminate material and process for its production

The present invention relates to a new type of laminate materials with a, preferably plate-shaped, substrate based on a wood material, in particular a synthetic resin-bonded wood fiber or hoizspan material, at least one of its surfaces being applied to and attached to it bound, protective function, but preferably at the same time also performing decorative function. The laminates are preferably used as building boards, e.g. B. for furniture and interior design in the broadest sense. Furthermore, the present invention relates to the production of the new, surface-coated decorative laminates, which are used in particular as construction, floor and furniture panels.

A large number of processes for the production of laminate materials equipped with a normally hard-wearing or abrasion-resistant surface coating have become known, whereby these processes are often only characterized by relatively minor changes in the process conditions, layer sequences, resin mixtures, laminate paper webs and the number thereof u. Different. from each other. However, these differences are often of crucial importance for the production process itself, for the processing and usage properties of the respective product and not least for the production and usage costs.

In the vast majority of cases, the basic manufacturing process is such that a print decoration provided with any print or, in some circumstances, a mere, e.g. B. uniformly colored, otherwise unprinted paper with a hard, especially thermosetting resin, preferably impregnated with an optionally modified, melamine, formaldehyde and / or urea resin and then or later with a - usually multi-layer - also with a thermosetting Resin or resin mixture, impregnated fiber, in particular paper web, which Unteriags- and / or carrier function, for. B. for an abrasive coating, and is usually referred to as a core sheet, preferably pressed under the influence of heat to a laminate sheet with the desired surface decor and / or desired surface structure.

If the resin of this decorative laminate web is essentially fully polymerized, that is to say hardened, it can be bonded to the substrate, usually a wood chipboard or wood fiber board, by adhesive bonding, possibly hot press bonding. Today, however, the technique of subjecting the resin of the decorative laminate web and the core sheet (s) only partially to a partial hardening predominates, and the pre-hardened laminates are then finally subjected to the intended base under the action of heat and pressure by means of the resin which then finishes. Bind substrate. The invention has now set itself the task of creating a new laminate material based on wood materials with a hard-wearing decorative coating, with which the decorative coating in addition to the desired color and while reducing the effort for the laminate components and the production costs / or a print decor provided in each case shows an optical or other additional effect related to the appearance and structure of the surface of the respective substrate material.

As the introductory remarks have shown, the production of the decorative laminate web that is ultimately to be applied to the substrate surface, that is to say the visible surface and to be bound to the same, is relatively complex only in that at least the printing decor that is provided as the outermost layer on the visible side or an overlayed paper web and the core-paper web formed in most cases with a plurality of layers must be combined after impregnation with the curable resin. This can take place immediately in the resin-wet state or after individual partial hardening to form prepreg sheets, which in any case requires considerable mechanical and manipulation effort in addition to the material expenditure. This multi-layer coating on the visible side also makes it necessary to coat the opposite side of the wood-material panels with a mostly multi-layer counter-coating to avoid warping or warping of the panels. In addition, with laminate-wood materials conventionally produced in the manner described, any impression of the surface of the substrate, be it only of an optical or structural nature, is completely lost.

The present invention thus relates to a new decorative laminate material based on a wood material, preferably in the form of boards, with a base substrate made of the said wood material, preferably wood fiber and / or wood chipboard, to which or which has a decorative coating based on paper impregnated with a hardened resin, at least on its visible surface, and which or which has a counter-coating on its non-visible surface, also based on paper impregnated with heat-hardened synthetic resin. The new decorative laminate material is characterized in that at least on the visible surface (s) of the wood material substrate only a single one, impregnated with an at least substantially hardened thermosetting resin, colored and / or with a Printed-decor layer of paper with reduced pigment filling in the range from 0 to 25%, in each case based on the total mass of the paper, is bound, the said paper layer with at least after hardening of the impregnating resin - translucent or translucent Effects and / or transparent paper and / or for Impregnation of the decorative paper of the decorative coating used synthetic resin after its curing is at least translucent, but preferably transparent, and finally the coloring and / or the printed decor with the appearance and / or structure and / or texture of the surface of the particular used Wood material substrate, preferably a wood fiber and / or wood chip material plate, is underlaid.

The outer optical and / or textural appearance of the

Decorative side of the new building and furniture panels from the defined, intended,

Print decor and from the "surface pattern" or the color shades of the wood-material surface superimposed by the above-mentioned, translucent through the paper.

This pattern can e.g. characterized by granularity, directional or multidirectionally non-directional fibrousness, mica and platelet effects or the like. On the one hand there are purely optical coloring and / or brightness effects, on the other hand often spatial pattern or stereo effects such. B. with small areas next to each other raised and recessed areas, often even with shadow effects, especially in oblique lighting.

The term "wood material" is not only limited to wood fiber or chipboard materials, but should also be understood to include plywood, OSB, wafer board, recycling boards (which do not necessarily have to consist only of wood). The following is explained in more detail about the prior art in the field in question and the position of the laminates according to the invention in this environment:

DE 43 41 590 A1 describes a coating method which is similar in principle, but there is by no means an attempt to show through and / or even reproduce the relief of the underlay structure on the coating; rather, in accordance with this DE-A1, an artificial surface structuring is used by means of massive application of paint , e.g. in the manner of a grain. Although there is talk of paper soaked in resin, that this paper should only be available in one layer, it is not expressly required there. In claim 2 of this step it is said that the surface consists of a paper-based film. A film labeled in this way should perhaps have a paper layer, but it only forms a basis.

The DD 256 478 A1 appears to be somewhat closer to the subject of the invention on first inspection. On page 2 the possibility of single-layer foils, which are pressed onto the substrate, is discussed there, but here, too, there is only talk of intentionally creating an artificial structuring of the surface by the action of the press. Participation of the substrate and its texture in the final appearance of the surface of the coated wood-based panels is not desired there and seems undesirable. There is no clear one there Instruction given in the direction to apply only a single overlay paper layer and to ensure that such a decor itself is transparent or after the impregnation with the resin and after curing of the resin at least translucent. Against the. Assuming only one intention to have any given structures of the subsurface shown or reproduced on the surface, the last paragraph of the chapter "Statement of the nature of the invention" of the DD-A1 speaks, where it reads: "It should also be emphasized that the blister markings of the subsurface are completely bridged and the furniture components manufactured in this way have an impeccable visual appearance. " As far as GB 2 301 312 A is concerned, it is in connection with

Laminates of "a sheet or foil" talk about how many "layers" this should have, is not carried out. According to this document, there is no question of a reproduction of the natural or given subsurface structure on the outer surface, but rather a reproduction of a wooden surface and the like is specifically targeted there. printed. The focus of this GB-A is very massive on the type and reproduction quality of this print decor. It is also the case with the process according to this GB-A that optical or relief interferences of a subsurface structure with the printed high-quality wood grain are regarded as disturbing.

Finally, reference is made to the E 20 214 B, which, however, provides for at least two-layer coatings, e.g. with at least one cellulose or paper layer and a resin-impregnated decorative film, and which font is more of a technological background.

Practically contrary to the usual and previously known coatings for wood-based materials based on resin-impregnated and hardened paper layers, in which the substrate is completely hidden, i.e. in most cases a wood-based panel and its or its surface structure by means of a sufficiently thick and opaque coating and is achieved, it is the aim and essence of the present invention to provide a coating on such a material substrate, in which the material surface of the base substrate and its visual impression without a supplementary additional printing pattern or an existing decorative printing pattern, by the coating "works through", in particular shines through or is correctly visible.

This goal was achieved in a particularly favorable manner by combining the measures or features as mentioned above. In order to achieve a balance between decor and underlay

Effects are the pigment components worked into the paper, e.g. B. lightening and white pigments, fillers or the like. To see. In order to bring out the surface structure of the substrate and the pure surface optics, the use of after resin curing, at least "translucent" papers, as indicated above, are advantageous. Under "translucent effects" any existing z. B. caused by zones of different amounts of filler pigment differences in transparency, z. B. to understand in the manner of a marbling. In order to bring out the pure look of the substrate surface, the is

Use of synthetic resins, which are essentially transparent after curing, as also provided, important.

It is particularly preferred - and this is one of the strengths of the new decorative laminate materials - if the decorative coating is formed with an "overlay paper" that is well known from laminate production, as is evident from claim 2.

Resin-impregnated papers have been included for the new decorative laminate materials

Basis weights according to claim 3 have been shown to be favorable, since on the one hand there is still no dominance of the substrate and its structures, which may already be perceived as a disturbance of the decor, but on the other hand the substrate effect is not yet fully covered.

Papers with impregnation properties, indicated in Guerley times, have proven best according to claim 4.

Decorative coatings based on the resin systems specified in claim 5 have also proven successful.

Claim 6 provides information as to the preferred amounts of the synthetic resin infiltrated into the paper with the decor after it has hardened.

Particularly effective results in terms of appearance and durability can be achieved by the technique of combining decorative coating and substrate mentioned in claim 7.

In general - and this means cost reduction - it can be assumed that, as is evident from claim 8, the surface of the substrate, that is to say of the wood or wood material, has not been treated further. In any case, a separate coating or intermediate coating below the decorative coating is not desirable.

In individual cases and for special purposes or effects, it can be advantageous if the surface carrying the decorative coating is mechanically surface-treated, e.g. B. ground, sandblasted, compressed or the like, is as provided in claim 9.

The invention further relates to a method for producing the new decorative laminate materials based on wood materials, as described above, the coating paper with a solution and / or dispersion or emulsion at least one thermosetting synthetic resin, preferably based on melamine / formaldehyde and / or melamine / urea, is impregnated and either the still impregnated-moist paper web or the mentioned paper web after partial curing of its synthetic resin, preferably in the form of prepreg -Blades or sheets, is bound to form a decorative coating at resin curing temperature and under pressure to the surface of a wood material substrate. Its essential feature now consists in the fact that a mere single-layer web of a colored and / or printed paper, preferably of such an overlay paper, is used. As such, the process for producing the new laminate

Material is not significantly different from the well-known and practically used production techniques. The only new thing is that it is targeted and intends a single-layer, preferably thin, paper web impregnated with the heat-curable resin without intermediate coatings, intermediate layers and the like. Like., Is applied directly to the visible surface of the wood or wood material substrate, this single-layer web has the same print decor and is therefore also the same as the decor web. As highlighted above, so-called "overiay paper" is preferably used.

The A n s p r u c h 11 indicates the components used in the process. As a backing coating, a similar resin / paper combination, as is provided for the visible-side coating, is preferably applied to the "back" of the substrate, that is to say in most cases of the building and furniture panels, as can be seen from A nsp r u c h 12.

The invention and its advantages are summarized as follows: Previously known wood-material panels were and are provided with a surface coating by means of printed papers, which serve both for the optical design and for improving the surface quality. This surface is made up of several layers of paper, the top layer being formed with a so-called overiay. In the previously known designs, this overlay is mostly transparent and serves to improve the surface quality, for example the abrasion values. The desired optical and other effects are achieved by layers of paper underneath. This means that any patterns or a replica of a wood grain are only printed on the paper layer underneath the overlay. Furthermore, a backing paper is normally applied to the back of the wood-material boards in order to prevent the boards from bending through the papers on the "front". The strength of the backing paper, which itself usually consists of several layers of paper, is measured according to the number of papers and their thickness on the visible or front side. The papers are soaked in a resin and pressed under pressure at elevated temperature with the wood-material plate and with each other.

The application of several layers of paper not only requires a large amount of material, but also a high level of handling. The essence of the invention is quite simplified and in no way restrictive: a pattern is printed on an overiay paper and the overiay paper thus equipped is pressed directly onto and with the wood-material plate. This means that the respective color of the decor is also influenced by the inherent color of the wood-material board. Not only does the use of paper and resin on the visible or front side decrease, but then a thinner paper on the back can also be used, e.g. B. with a grammage of 80 g / m ² instead of 120 g / m ² . Furthermore, the manufacturing effort is reduced because only a single layer of paper has to be applied and pressed. It is of course favorable if this surface produced in this way has no stains or other optically disturbing irregularities. The invention is illustrated by the following example:

Example:

In the conventional way and under the usual conditions of hot pressing, a commercially available melamine-urea resin dispersion is used to obtain a commercially available overiay paper impregnated on the visible side with the heat-hardened resin, and with a desired print decor, and on the underside with a similar but not printed overiay -Paper coated high density wood fiber (HDF) board.

The overlay papers used both had a grammage of 25 g / m ² . The pressing time was reduced by about 20% compared to the usual pressing times at the usual pressing temperatures.

A panel with the decor on the visible side was obtained, the color shades and the fiber structure of the HDF panel surface being permanently visible through the print decor.

Claims

Patent claims:

1. Decorative laminate material based on a wood material, preferably in the form of plates, with a base substrate made of the wood material mentioned, preferably wood fiber and / or wood chipboard, to which or which at least on its visible surface a decorative coating based on paper impregnated with a hardened resin, and which or which has a counter-coating on its non-visible surface, also based on paper impregnated with heat-hardened synthetic resin, characterized in that at least to the visible surface (s) of the wooden

Material substrate in each case only a single layer of paper impregnated with an at least substantially hardened thermosetting resin, colored and / or provided with a printed decoration, with a reduced pigment filling in the range from 0 to 25%, in each case based on the total mass of the paper , is bound, the paper layer mentioned having at least after hardening of the impregnating

Resin - translucent or translucent effects or transparent paper and / or the synthetic resin used to impregnate the decorative paper of the decorative coating after its curing is at least translucent, but preferably transparent, and finally the coloring and / or the print -Decor is underlaid with the optics and / or structure and / or texture of the surface of the wood material substrate used, preferably a wood fiber and / or wood chip material plate.

2. Material according to claim 1, characterized in that the decorative coating with a single layer of a colored and / or provided with a print decor

Overlay paper, preferably α-cellulose paper, is formed.

3. Material according to claim 1 or 2, characterized in that the decorative coating with a single layer of a color and / or a print decor paper with a grammage of 20 to 120 g / m ² , preferably from 60 to

90 g / m ^{2 is} formed.

4. Material according to one of claims 1 to 3, characterized in that the decorative coating with only one layer of a colored and / or with a print decor paper with Guerley values in the range of 5 to 25 s, preferably of

10 to 20 s.

5. Material according to one of claims 1 to 4, characterized in that the decorative coating with only one layer of a colored and / or with a print decor paper with an impregnation with a heat-hardened resin, preferably based on melamine with formaldehyde and / or urea.

6. Material according to one of claims 1 to 5, characterized in that the amount of hardened synthetic resin contained in the decorative coating is 50 to 120%, preferably 60 to 80%, in each case based on the amount of decorative paper contained therein .

7. Material according to one of claims 1 to 6, characterized in that the decorative coating is bonded to the wood-material substrate by hot pressing.

8. Material according to one of claims 1 to 7, characterized in that the surface provided with the decorative coating of the wood-material substrate is mechanically untreated.

9. Material according to one of claims 1 to 7, characterized in that the surface of the wood-material substrate provided with the decorative coating is changed by mechanical surface treatment.

10. A method for producing new decorative laminate materials based on wood materials according to one of claims 1 to 9, wherein the coating paper with a solution and / or dispersion or emulsion of at least one thermosetting resin, preferably based on Melamine / formaldehyde and / or

Melamine / urea, is impregnated and either the still impregnated-moist paper web or the above-mentioned paper web after partial curing of its synthetic resin, preferably in the form of prepreg sheets or sheets, with formation of a decorative coating for resin Hardening temperature and under pressure is bound to the surface of a wood material substrate, characterized in that a mere single-layer web of colored and / or with a print decoration paper, preferably such an overlay paper, is used .

11. The method according to claim 10, characterized in that at least one or one of the papers or paper mentioned in claims 1 to 9 in detail

Qualities and / or resin systems and / or wood-material substrates are used.

2. The method according to claim 10 or 11, characterized in that, preferably by means

Hot pressing, on the opposite or rear side of the wood material substrate, preferably a wood fiber and / or wood chipboard, one of the at least similar or identical combination of paper and resin system is bound on the visible side.