DE102015004239A1 - DPL laminate flooring panels of stress class 34 - Google Patents

Abstract

A process for the production of an impact-resistant laminate structure comprising the direct compression of an abrasion-resistant overlay paper with hard material particles, one or more overlay papers without hard material particles, a resinated decorative paper, one or more resinated papers without hard particles, a backing plate and one or more resinated Gegenzugpapiere. The resulting laminate structures are suitable for the production of laminate floor panels that meet the stress class 34 (according to EN 13329).

Description

The present invention relates to methods of making an impact resistant laminate construction having impact resistance and abrasion resistance meeting stress class 34 (according to US Pat Standard EN 13329 ) suffice. The invention comprises the direct compression of an abrasion-resistant overlay paper with hard material particles, one or more overlay papers without hard material particles, a resinated decor paper, one or more resinated papers without hard material particles, a carrier plate and one or more resinated Gegenzugpapiere. Furthermore, the present invention relates to the laminates obtainable by this process and their use for the production of laminate flooring panels.

The invention provides an efficient process for producing high strength laminates. By the laminate structures obtainable by the process according to the invention, products are provided which are distinguished by a high resistance to mechanical stresses, in particular to impact and abrasion. The laminates obtained are also comparatively thin and can be produced in comparison to similarly loadable laminates from the prior art with a significantly reduced cost of materials. Thus, the invention also provides a material-saving and cost-optimized method for the production of highly loadable laminates and low-cost laminates of high quality. The laminate structures obtainable by the process according to the invention are used as cover layers for. B. for furniture, doors or floors use that are exposed to a special impact and abrasion. Particularly advantageous are the advantageous properties when using these laminate structures for the production of floor panels of the stress class 34 (according to EN 13229 ) to carry.

Laminate floors have established themselves in recent years as a cost-effective alternative to parquet floors. They are available in attractive decors on the market, are easy to process, are durable and extremely easy to clean. Various laminate flooring panels that have long been known in the art include a substrate, such as an HDF or MDF panel. In principle, however, other carrier materials are also suitable. On the underside of the carrier plate usually so-called Gegenzugpapiere applied, which consist of resin-impregnated papers and prevent the bending of the laminate with temperature changes or changes in humidity. The upper side of the laminate floor panel usually consists of a laminate, which usually consists of a resin-soaked decorative paper and a resin-impregnated overlay paper. In this case, melamine resin is usually used for impregnation.

The overlay paper can be made resistant to mechanical wear (scratch and abrasion resistant) by the addition of hard particles, either applied as a separate layer or added to the resin. Depending on the desired thickness, the laminates may also comprise a plurality of core layers of resin-impregnated papers. In the production of known laminate flooring panels, the resin-impregnated papers are usually bonded together using pressure and temperature.

Laminated floor panels are available in different load classes that correspond to different uses. They can be obtained by the structure and the nature of the applied to the top of the substrate laminates. The impact resistance and the abrasion resistance are in accordance with the Standards EN 438-5 (Laminates HPL for the floor area) and EN 13329 (Laminate floors) essential parameters for the assignment of the floor panels to the stress classes, as shown in the following tables. Table 1: Stress classes for laminate flooring elements based on thermosetting aminoplast resins in accordance with EN 13329 EN 13329 abrasion classes AC 1 AC 2 AC 3 AC 4 AC 5 AC 6 Abrasion (Taber test according to standard) ≥ 500 ≥ 1000 ≥ 2000 ≥ 4000 ≥ 6000 ≥ 8500 Impact resistance small ball ≥ 8 ≥ 8 ≥ 8 ≥ 12 ≥ 15 ≥ 20 Exposure class Class 33 Class 34 Table 2: Stress classes for high pressure decorative laminates (HPL) based on curable resins according to EN 438-5 EN 438-5: 2005 abrasion classes AC 1 AC 2 AC 3 AC 4 AC 5 Abrasion (Taber test according to standard) ≥ 900 ≥ 1800 ≥ 2500 ≥ 4000 ≥ 6500 Impact resistance small ball ≥ 20 ≥ 20 ≥ 20 ≥ 20 ≥ 20 Exposure class Class 33

These standards also specify the methods of determination for these parameters. Thus, the impact resistance, i. H. the resistance to impact, in the "small ball test" determined by means of a standardized impact tester, in which a small ball is beaten by means of a firing pin on the test object. For the abrasion test, a Taber tester is used. In this case, a sample of the laminate floor measuring 10 × 10 cm under two wheels made of rubber, which are covered with well-defined corundum emery paper strips turned. Every 200 revolutions the corundum strips are changed. If the decor print is visibly damaged, the endpoint is reached.

Different processes are available for the production of laminate flooring. HPL floors (high-pressure laminate floors) consist of overlay, decorative paper and several core layers of phenolic resin-impregnated papers, a backing plate and a backing paper. During production, the sheets of impregnated papers are first pressed under high pressure (≥ 5 MPa) into laminates. For this purpose, usually multi-daylight presses or continuously operating presses are used. The pressing times are 6 to 15 minutes. After cooling, the obtained laminates are bonded (usually pressed or glued) to the backing plate equipped with a backing paper. The resulting laminates usually have an extremely durable surface. According to EN 438-5 is the required impact strength (small ball) for all stress classes 20 N. However, the manufacturing process for HPL flooring is comparatively time, labor, cost and material intensive, which is reflected in addition to the good surface quality, among other things, in high selling prices.

In the production of DPL laminate flooring (direct pressed laminate flooring), the impregnated paper is "fused" directly to the substrate (HDF, MDF or chipboard) during the pressing process with the aid of short-cycle presses. In contrast to the HPL process, the pressing surfaces are significantly larger and the cycle times significantly shorter. Usual pressing times are between 8 and 30 seconds. Contrary to the HPL process, with which almost any number of impregnated papers / layers can be pressed into a laminate, in the DPL process usually only up to three layers (very rarely four layers, then usually one layer is placed twice) impregnated papers on the laminate top pressed (overlay, decorative paper, underlay). Also in the DPL process for the production of laminate flooring after EN 13329 On the underside of the substrate, a suitable paper, also impregnated with aminoplast resin, must be used for the balance (flatness) of the resulting floor panel (counterpoise impregnate). The DPL process is faster and less expensive than the HPL process. However, due to the limited number and thickness of the laminate floor compressible layers, it is difficult to obtain laminate structures using the DPL technique, which are suitable for the production of 34 class floor panels EN 13329 suitable. There is therefore still a need for efficient processes involving the manufacture of laminate structures or floor panels based thereon having an impact strength of at least 20 N (determined by the method with the small ball) and a Taber abrasion of more than 8500 revolutions according to class 34 according to Standard EN 13329 allow.

The requirements for impact resistance while achieving the required abrasion resistance usually make special demands on the product properties of the overlay. To increase the abrasion resistance of the overlay papers are usually hard material particles, eg. As corundum or other metal oxides, added, while the impact resistance can be increased by the pressing of backing layers (underlay papers) under the decorative layer. However, both measures influence each other, so that a laminate with the desired properties can not be readily obtained.

A considerable part of the required efficiency of the abrasion resistance producing hard material particles is lost through the use of the underlayers. When using an underlay to reach the Impact resistance in the case of DPL buildup requires a significant increase in the usually required contents of the hard material particles in the overlay (eg corundum). To achieve the desired impact resistance of class 34 ( Standard EN 13329 ), it is usually necessary to use suitable underlays which have a grammage of at least 200 g / m ² , preferably 250 to 300 g / m ² . The impregnates used in the prior art to increase the impact strength are provided with a lower resin content than is the case for decorative surface impregnates and overlays. The underlays mentioned usually have a degree of treatment ≤ 50%, usually between 40 and 50%.

It is also possible to use two abrasion-resistant overlays with a suitable proportion of hard material. However, the impact resistance of this construction is comparably poorer and the material required to achieve abrasion resistance is relatively large. Floor panels manufactured using a low-resin underlay or using overlays containing more than one hard material particle, if they have the desired stress class, require a correspondingly increased counterbalance to compensate, which ultimately leads to a further increase in the use of materials.

• a) ein abriebfestes Overlaypapier enthaltend Hartstoffpartikel,
• b) ein oder mehrere Overlaypapiere ohne Hartstoffpartikel,
• c) ein beharztes Dekorpapier,
• d) ein oder mehrere beharzte Papiere ohne Hartstoffpartikel,
• e) eine Trägerplatte sowie
• f) ein oder mehrere beharzte Gegenzugpapiere.

In the investigations on which the present invention is based, it has surprisingly been found that laminate structures which meet the requirements of the stress class 34 according to the cited Standard EN 13329 meet or can be used to produce correspondingly resilient floor panels, can be obtained by the direct compression of the following layers:

• a) an abrasion-resistant overlay paper containing hard material particles,
• b) one or more overlay papers without hard material particles,
• c) a resinated decorative paper,
• d) one or more resinated papers without particles of hard material,
• e) a support plate as well
• f) one or more resinated counterfeit documents.

The layers are bonded together in the order given using a pressure between 150 N / cm ² and 600 N / cm ² for a period between 10 and 45 seconds.

It has surprisingly been found that the use of at least one vollbeharzten overlay paper containing no hard particles under the abrasion resistant overlay paper with simultaneous use of at least one other resinated, preferably fully resinated paper without hard material particles under the decor paper results in a laminate structure, the desired requirements of Stress class 34 (according to EN 13229 ) enough.

The overlay papers of layers a) and b) must first meet the usual requirements for transparency and surface closure and can therefore only have a limited layer thickness. In addition, there are requirements for the type and amount of resin used and the hard material content.

As abrasion-resistant overlay paper in layer a) in the present process fully resinated, melamine resin-containing overlay papers having a resin content of between 53 and 82% based on the total weight of the impregnate and a corundum amount between 5 and 60 g / m ² with an average corundum grain size between 80 and 130 microns Commitment. Such corundum is (former Treibacher) sold for example by the company. Imerys Fused Minerals GmbH under the trade name ALODUR ZWSK-180 and suitable melamine resins are, for example, under the trade name Madurit ^® (Fa. Ineos Melamines) available on the market. Suitable base papers for impregnation with aminoplast or phenoplast resins are papers having a grammage of between 5 and 150 g / m ² , preferably a grammage of between 10 and 60 g / m ² . Such base papers are, for example, (noble) celluloses, which are offered, for example, by Glatfelter. Particularly preferred for layer a) is an overlay paper of a grammage of 200-208 g / m ² , with a corundum content of 50 to 60 g / m ² , which is based on a pulp paper of a grammage of 15 to 35 g / m ² .

As overlay papers in layer b) for impregnation with aminoplast or phenolic resins suitable papers a grammage between 5 and 150 m ² used with a resin coating degree 53-82% (based on the Imprägnatendgewicht) g / are preferably vollbeharzte. Particularly preferred in layer b) overlay papers are used, which are suitable for impregnation with aminoplast or phenoplast resins fully impregnated with a suitable resin paper having a grammage between 10 and 60 g / m ² with a degree of treatment of 53 to 82% (based on the final impregnating ). Such a degree of coverage (53-82% based on the final impregnation weight) is hereinafter referred to as "fully dented" and the corresponding treated paper referred to as "fully resin impregnated". This corresponds to a total weight of the impregnate of 53 g / m ² at 53% cure using a paper with a grammage of 25 g / m ² (unbeharred) and a total weight of the impregnate of 139 g / m ² at 82% cure. The percentages refer to air-dried impregnate (impregnated lutro). Suitable base papers include papers usable for the production of overlay impregnates, which are available, for example, from Glatfelter.

The papers suitable for producing the overlay papers are impregnated with the aid of a one-step impregnation method according to the current state of the art to the abovementioned degrees of refining, and then dried to residual moistures of usually 5.5 to 7.5%.

In layer d), it is preferred to use papers comprising one or more fully-cured, impregnated papers. A fully cured, impregnated paper according to the invention comprises a resin content of 53 to 82% based on the total weight of the impregnate (air-dried). Particularly preferred in paper d) with a suitable resin vollbeharzte suitable for impregnation with aminoplast or phenolic resins papers of a grammage between 5 and 250 g / m ² with a degree of treatment of 53 to 82% (based on the final impregnating weight) used. Papers suitable for use in layer d) are base papers for the production of overlay papers (for example from Glatfelter), decor papers (for example from Technocell Dekor), regenerated papers (for example from Gebr. Hoffsümmer Spezialpapier GmbH & Co. KG) or Kraft papers (for example from Gebr. Hoffsümmer Spezialpapier GmbH & Co. KG). In a particularly preferred embodiment, a vollbeharztes with a suitable resin paper from pulp a grammage of 10 to 60 g / m ² (having a degree of resination of 53-82% based on the Imprägnatendgewicht) is used in layer d). As resins Aminoplast- or phenoplast resins are used, the z. As marketed by the company. Ineos Melamines under the trade name Madurit ^® .

Particularly good results were obtained with a method in which the same overlay papers (same base paper with the same or similar degree of coverage) were used in layers b) and d).

As decor papers in layer c), suitable papers of a grammage between 20 and 200 g / m ² with a degree of between 40 and 95% (based on the final impregnation weight) are suitable for impregnation with aminoplast or phenoplast resins in the present process. Particular preference is given to using, in layer c), papers which comprise decorative paper suitable for impregnation with aminoplast or phenoplast resins and having a grammage of between 35 and 90 g / m ² and a degree of coverage of from 50 to 60% (based on the final impregnation weight). Suitable papers include decorative papers, for example from Technocell Dekor.

As carrier plates are commercially available MDF or HDF plates, which are available for example from Egger under the trade name MDF-KT or HDF-KT on the market, with particularly good results were achieved using HDF plates.

As back-up papers in the layer f) usual structures are used. Regenrat and Natron kraft papers are preferably used here, which are suitable for impregnation with aminoplast or phenoplast resins. Usually, countertraction papers having a grammage of between 50 and 140 g / m ² and a degree of cure of between 53 and 82% are used. Particularly preferred are countertraction papers having a grammage of between 70 and 90 g / m ² and a degree of cure of between 55 and 65%. Suitable papers are, for example, the counter-documents of Gebr. Hoffsümmer Spezialpapier GmbH & Co. KG.

The use of a non-abrasion overlay (overlay without hard particles) with a significantly lower grammage (both of the paper used and the amount of resin used) than the commonly used high grammage underlays results in a significant improvement in impact strength without compromising abrasion resistance. These improvements with a comparatively low use of material are due to the high degree of treatment of the overlay papers.

Due to the comparatively low use of material on the upper side, the construction described requires a comparatively smaller counter-pull. This results in a further advantage of the possibility to use a Gegenzugimprägnat with comparatively low total weight. This applies in comparison to the usually necessary counterimpulse impregnates when using low-resinated underlays with the normally necessary, high impregnate weight. This can on the one hand reduces material costs On the other hand, floor panels with a significantly reduced final weight and high load capacity are available, which has a positive effect on the overall balance of the process.

In the production of HPL laminates, a higher use of material is also required in order to achieve comparable impact resistance while achieving the desired abrasion. The DPL laminate structure according to the invention has the same requirements as compared to an HPL structure, to realize it much more efficiently.

Without wishing to be limited to the following examples, the invention is characterized in detail by them.

The following abrasion-resistant overlay papers were used in the structures described below. The base paper used was bleached precious pulp and, as the resin, melamine resin crosslinked with formaldehyde. product paper type Grammage paper in g / m ² Amount of resin without corundum Film weight in g / m ² Corundum content in g / m ² Resin content in impregnate (without corundum) in% Liquilay AC 6 Glatfelter OVL 25 125 205 55 61

The abrasion-resistant overlay paper was prepared as follows in a two-step prior art impregnation process. The paper was first impregnated from high-grade pulp (= pre-impregnation), giving a paper of a grammage of about 70 g / m ² incl. Paper, on which the corundum was subsequently applied on the underside in the so-called ARP process. The residual moisture content in the final overlay impregnate ranged from 6.3 to 6.8%.

As decorative paper, a partially resinated decor paper was used in the laminate structures described below, which is constructed as follows. product paper type Grammage paper in g / m ² Amount of resin without corundum Film weight in g / m ² Corundum content in g / m ² Resin content in impregnate (without corundum) in% Advance decor 50 g / m ² Lamigraf D3646-0005 50 47 97 - 48

The decor paper Decor Advance 50 g / m ² has been prepared according to the state of the art using a paper Lamigraf D3646-0005 in a one-step impregnation process. The content of residual moisture in the impregnate was between 5.3 and 5.8%.

The carrier plate used was MDF and HDF plates from Egger. It has been found that the laminates pressed onto HDF boards generally have a better impact resistance than the laminates pressed on MDF boards.

As retraction papers, impregnates made in a two-stage impregnation process of the prior art were used in the laminates under investigation. The content of residual moisture in the impregnate was between 6.3 and 6.8%.

The following paper layers were used as impact-resistant overlay papers. The base paper used was bleached precious pulp and, as the resin, melamine resin crosslinked with formaldehyde. product paper type Grammage paper in g / m ² amount of resin Film weight in g / m ² Corundum content in g / m ² Resin content in impregnate in% MV2014-052 Glatfelter OVL 25 50 75 0 66.7

The impact resistant overlay papers were made in a one step prior art impregnation process. The content of residual moisture in the impregnate was between 6.8 and 7.1%.

Commercially available kraft, regenerated and decorative papers were used as base papers for the underlay papers used. In addition, base papers suitable for the production of overlay papers were used. The resin used was melamine resin, which was crosslinked with formaldehyde. The individual products are composed as follows. product paper type Grammage paper in g / m ² amount of resin Film weight in g / m ² Resin content in impregnate in% Underlay Advance 80g / m ² Kraft paper 80 84 164 51.2 NKR 60 RR counteracting 60 108 168 64.3 NKR 90 RR counteracting 90 120 210 57.1 MV2014-052 Glatfelter OVL 25 50 75 66.7

The underlay papers were made in a one step prior art impregnation process. The residual moisture content of the underlay papers after air drying was between 6 and 7%.

The paper layers listed above were pressed together in the laminate structures described below. A laboratory press from Memmert was used for the following pressing parameters: press temperature 186 ° C. on the upper press plate and 189 ° C. on the lower press plate, press pressure 350 N / cm ² , press time 15 seconds. The resulting laminates were then with the aid of in Standard EN 13229 tested in terms of impact resistance and abrasion. For the determination of the impact strength, the test was used with the small ball; The abrasion was determined by the Taber test. For class 34, the laminate must conform to EN 13229 have Taber abrasion of ≥8,500 revolutions and impact strength (as determined by the small ball) of ≥20N.

Comparative Example 1

Laminate structure:

Abrasion-resistant overlay (Liquilay AC 6) - Decor Advance 50 g / m ² - HDF plate - Backing → Abrasion Taber: 10,300 → Impact resistance: 15

Product does not meet the requirements of the stress class 34 EN 13229 ,

Comparative Example 2:

Laminate structure:

Abrasion-resistant overlay (Liquilay AC 6) - Impact-resistant overlay (MV2014-052) - Decor Advance 50 g / m ² - HDF board - Backing → Abrasion Taber: 11,100 → Impact resistance: 18

Product does not meet the requirements of the stress class 34 EN 13229 ,

Comparative Example 3

Laminate structure:

Abrasion-resistant overlay (Liquilay AC 6) - Decor Advance 50 g / m ² - Underlay (NKR 60 RR) - HDF plate - Backing → Abrasion Taber: 7400 → Impact resistance: 20

Product does not meet the requirements of the stress class 34 EN 13229 ,

Comparative Example 4

Laminate structure:

Abrasion-resistant overlay (Liquilay AC 6) - Decor Advance 50 g / m ² - Impact-resistant overlay (MV2014-052) - HDF plate - Backing → Abrasion Taber: 7600 → Impact resistance: 18

Product does not meet the requirements of the stress class 34 EN 13229 ,

Example 1:

Laminate structure:

Abrasion-resistant overlay (Liquilay AC 6) - Impact-resistant overlay (MV2014-052) - Decor Advance 50 g / m ² - Underlay (NKR 60 RR) - HDF plate - Backing → Abrasion Taber: 11,200 → Impact resistance: 22

Product meets the requirements of stress class 34 according to EN 13229.

Example 2:

Laminate structure:

Abrasion-resistant overlay (Liquilay AC 6) - Impact-resistant overlay (MV2014-052) - Decor Advance 50 g / m ² - Underlay (NKR 90 RR) - HDF plate - Backing → Abrasion Taber: 11,200 → Impact resistance: 22

Product meets the requirements of class 34 ( EN 13229 )

Example 3:

Laminate structure:

An abrasion resistant overlay (Liquilay AC 6) - Impact-resistant overlay (MV2014-052) - Decor Advance 50 g / m ² - Impact-resistant overlay (MV2014-052) - HDF - exchange → Abrasion Taber: 10,400 → Impact resistance: 22

Product meets the requirements of stress class 34 according to EN 13229 ,

The tests have shown that directly pressed laminates comprising under the abrasion-resistant overlay paper at least one impact-resistant overlay paper (fully resinated paper without hard particles) and also a fully resinated underlay paper, a impact resistance (test with a small ball) and an abrasion resistance (Taber test) , which meet the requirements of the stress class 34 EN 13229 suffice.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• Standard EN 13329 [0001]
• EN 13229 [0002]
• Standards EN 438-5 [0005]
• EN 13329 [0005]
• EN 13329 [0005]
• EN 438-5: 2005 [0005]
• EN 438-5 [0007]
• EN 13329 [0008]
• EN 13329 [0008]
• Standard EN 13329 [0008]
• Standard EN 13329 [0010]
• Standard EN 13329 [0012]
• EN 13229 [0014]
• Standard EN 13229 [0038]
• EN 13229 [0038]
• EN 13229 [0040]
• EN 13229 [0042]
• EN 13229 [0044]
• EN 13229 [0046]
• EN 13229. [0048]
• EN 13229 [0050]
• EN 13229 [0052]
• EN 13229 [0053]

Claims (11)

A method of making an impact resistant laminate structure having impact strength and abrasion resistance satisfying stress class 34 (according to standard EN 13329) comprising compressing the following layers in the order given: a) an abrasion-resistant overlay paper containing hard material particles, b) one or more overlay papers without hard material particles, c) a resinated decorative paper, d) one or more resinated papers without particles of hard material, e) a carrier plate, such as an MDF or HDF plate, as well f) one or more resinated counterfeit documents. The method of claim 1, wherein the paper or papers in layer d) comprise a fully cured impregnated paper. A method according to any one of claims 1 or 2, wherein the paper or papers of layer d) comprise a paper of a grammage between 5 and 250 g / m ^2, fully resinated, suitable for impregnation with aminoplast or phenoplast resins, for impregnation with aminoplast or phenoplast resins. A method according to claim 3, wherein the paper or papers of layer d) is a paper of a grammage of 10 to 60 g / m ² , fully resinated with a suitable resin and suitable for the production of overlay papers. Method according to one of claims 1 to 4, wherein the overlay paper or the overlay papers of the layer b) a full resin with a suitable resin, suitable for impregnation with aminoplast or phenoplast resins and for the production of overlay papers paper having a grammage between 5 and 150 g / m ² include. Method according to one of claims 1 to 4, wherein the overlay paper or the overlay papers of the layer b) a full resin with a suitable resin, suitable for impregnation with aminoplast or phenoplast resins and for the production of overlay papers paper having a grammage between 10 and 60 g / m ² include. Method according to one of claims 4 to 6, wherein in the layers b) and d) the same papers are used. A method according to any one of claims 1 to 7, wherein the papers of layers b) and d) are impregnated with melamine resin. Method according to one of claims 1 to 8, wherein a suitable HDF plate is used as the carrier plate. Laminate structure preparable by a method according to any one of claims 1 to 9. Use of the laminate structure according to claim 10 for the production of a laminate floor panel.