Laminate with Anti-splinter layer

Abstract

The present invention relates to a laminate, more particularly for usage in interior trim elements of vehicles. The laminate comprises a first number of resin-impregnated paper layers (3a, 3b, 3c) and a second number of resin-impregnated paper layers (3a, 3b, 3c). Arranged between the first number of resin-impregnated paper layers (3a, 3b, 3c) and the second number of resin-impregnated paper layers (3a, 3b, 3c) is an anti-splinter layer (4).

Description

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[0002] Lignum Technologies AG K169685WO MAJ / Moh

[0003] Laminate with spatter protection layer

[0004] 1. Technical area

[0005] 5

[0006] The present invention relates to a laminate with a splinter-resistant layer, particularly for use in interior trim elements of vehicles. Furthermore, the invention relates to a method for producing such a laminate. 0 2. Technical Background

[0007] A laminate is a fiber composite material in which several layers are bonded together. Typically, a laminate consists of several layers of paper or fabric, which may be impregnated with phenolic resin at the core and melamine resin as the outer layers. These layers can then be bonded together under heat and pressure.

[0008] Decorative laminates are used in both interior design and building construction, for example, as facade cladding. Due to their well-known advantageous properties (e.g., stability), laminates are also desirable for use as cladding elements, for example, in buses or trains. Used as a cladding element, the laminate can have a visually appealing effect and, if necessary, accommodate or hold functional elements such as handles. Furthermore, a laminate used as a cladding element can also serve the function of acoustically sealing the interior.

[0009] An example of such a conventional laminate is shown in Fig. 1. This laminate consists of a 3 mm thick compact board with two decorative sides. To produce such a laminate, a large number of phenol-impregnated papers 3 are arranged between two melamine-impregnated decorative papers 1, 2. This layer structure is pre-commissioned, i.e. the individual layers are layered on top of one another and then pressed at high temperature and high pressure to form a flat laminate. The laminate produced in this way is characterized by high strength and rigidity, so that it can also be used as a load-bearing cladding element. The decorative papers can be provided with a motif (e.g. wood, metallic, marble), which determines the visual impression of the laminate.

[0010] A problem with the use of such laminates, however, is their high tendency to splinter when broken. An accident, such as a road or rail collision, can lead to significant damage to the wall paneling, creating sharp-edged splinters and panel fragments that can cause serious injuries to the occupants. Due to this risk of injury, previously known laminates are unsuitable for use in vehicle interior trim elements.

[0011] It is therefore the object of the present invention to provide improved laminates. In particular, an improved laminate should enable use in vehicle interior trim elements while ensuring safety.

[0012] These and other objects which will become apparent to the person skilled in the art from the present description are achieved by a laminate according to claim i and a method for producing a laminate according to claim 14.

[0013] ,2. Content of the invention

[0014] A first aspect of the invention relates to a laminate. A laminate according to the invention (or also layered composite material or laminate) can be a fiber composite material formed from multiple layers, as is customary.

[0015] The laminate is ideally suited for use in interior paneling elements, such as in vehicles such as buses or trains. For example, walls, ceilings, or floors can be clad with the laminate. The laminate can also be used as a cladding element in building facades or as a cladding element in the interior design of buildings. The laminate can have a load-bearing function, meaning its function is not limited to (decorative) cladding or room partitioning.

[0016] The laminate comprises a first number of resin-impregnated paper layers and a second number of resin-impregnated paper layers. Paper layers can be selected for this purpose, as used in laminates known from the prior art. The individual paper layers preferably each have a paper weight of 50 to 300 g / m². 2 , preferably from 80 to 220 g / m2 The first number and the second number are each preferably greater than 1. For example, the first number and the second number can each be 5. The number of paper layers can influence the stiffness and thickness of the laminate. For example, the laminate can comprise 5 paper layers per mm of material thickness. The first number of paper layers and the second number of paper layers can form a laminate core. Preferably, the paper layers are made of the same material, have substantially the same paper weight, and have substantially the same strength / thickness.

[0017] The laminate further comprises a splinter protection layer arranged between the first number of resin-impregnated paper layers and the second number of resin-impregnated paper layers. The splinter protection layer is designed to reduce the tendency of the laminate to splinter upon damage. For example, the splinter protection layer can be arranged as a flexible layer within the inherently brittle laminate to achieve the desired splinter protection effect.

[0018] The inventor has discovered that the splinter protection layer ensures that the laminate retains its shape even under high force, particularly when the laminate breaks. Potential sharp-edged elements, such as splinters from the paper layers, remain in the laminate rather than breaking out. Vehicle occupants, for example, are protected in this way. The inclusion of the splinter protection layer allows the overall layer thickness to be reduced, for example with a view to application in the transportation industry as cladding elements in interior fittings. This saves material and weight. Preferably, the splinter protection layer of the laminate is more flexible than the first and second number of paper layers. Such a splinter protection layer adds a flexible layer to the otherwise rather brittle laminate, which only breaks under higher loads than the laminate core, thus achieving the splinter protection effect.

[0019] Preferably, the first and second numbers are equal. Preferably, the laminate is symmetrical in cross-section, at least with respect to the paper layers and the splinter protection layer. This prevents the laminate from warping.

[0020] The splinter protection layer preferably comprises a metal foil. For example, a steel foil can be used as a splinter protection layer. A metal foil can provide a flexible layer that does not break under the load at which the other elements of the laminate (the paper layers of the laminate core) would burst. The inclusion of the metal foil thus increases the elastic modulus and fracture strength of the laminate many times over.

[0021] The metal foil is preferably made of aluminum. The aluminum foil preferably has a thickness of 0.7 to 0.9 mm, more preferably approximately 0.8 mm. It has been found that splinter protection layers designed in this way have good splinter protection and can also be produced cost-effectively.

[0022] The splinter protection layer, which is designed as a metal foil, preferably comprises a multilayer metal foil. Preferably, at least one additional resin-impregnated paper layer is arranged between the individual layers of the multilayer metal foil. The individual layers of the multilayer metal foil can be constructed identically, consisting of the same material and of the same thickness. With such a multilayer metal foil, the splinter protection effect can be further enhanced.

[0023] The splinter protection layer (preferably formed as a metal foil) is preferably coated on both sides. The coating strengthens the bond between the splinter protection layer and the paper layers. The splinter protection layer can be coated, for example, with thermally curable synthetic resins, e.g., melamine-formaldehyde resins or urea-formaldehyde resins, or a mixture of both. Alternatively, the splinter protection layer can also be coated with varnishes, such as UV-curing or thermally curing varnishes. The coating enables a strong bond and prevents delamination during use.

[0024] Further preferably, the shatter-resistant layer (preferably formed as a metal foil) is coated with an adhesion promoter. The adhesion promoter can, for example, be present as a lacquer layer on the surfaces of the aluminum foil used as the shatter-resistant layer. In another example, thermally cured acrylic-based lacquers can serve as the adhesion promoter. Such a coating enables a good bond and prevents delamination during use.

[0025] The splinter protection layer (preferably formed as a metal foil) preferably has a thickness of 0.05 to 0.20 mm, more preferably 0.06 to 0.15 mm, more preferably 0.07 to 0.10 mm, and more preferably approximately 0.08 mm. This provides a good compromise between splinter protection and material costs.

[0026] The splinter protection layer preferably comprises (instead of or in addition to a metal foil) glass fleece, polyethylene terephthalate (PET), fabric, and / or carbon fibers. Here, too, the splinter protection layer is preferably prepared in such a way that it forms a stable bond with the paper layers. For example, the surface can be activated (e.g., by irradiation) to enable improved bonding to the paper layers.

[0027] The resin-impregnated paper layers are preferably impregnated with formaldehyde resin. The resin used can preferably be a phenol-formaldehyde resin, melamine-formaldehyde resin, or melamine-urea-formaldehyde resin. Those skilled in the art will understand how to use suitable, previously known resin formulations to impregnate the paper layers. The resin-impregnated paper layers preferably contain a resin content of 40 to 60 wt.%. The resin-impregnated paper layers preferably contain volatile components of 5 to 7 wt.%. With such an impregnate, advantageous mechanical properties can be achieved while reducing the risk of composite reinforcements in the form of blisters.

[0028] The laminate preferably comprises a first and a second melamine-impregnated decorative paper. The paper layers and the splinter protection layer are arranged between the first and second decorative papers. The decorative papers can have individual motifs to give the laminate the desired visual impression. The structure of the laminate thus generally corresponds to the prior art described with reference to Fig. 1, with a splinter protection layer now advantageously incorporated into the laminate core.

[0029] Those skilled in the art will understand that the laminate can also comprise multiple splinter protection layers, with additional resin-impregnated paper layers, for example, being arranged between the individual splinter protection layers. The multiple splinter protection layers can be identical to one another or can be designed differently.

[0030] A further aspect of the invention relates to a method for producing a laminate which, as described, is particularly suitable for use in interior trim elements of vehicles. The method comprises providing a first number of resin-impregnated paper layers, providing a second number of resin-impregnated paper layers, arranging a splinter protection layer between the first number of resin-impregnated paper layers and the second number of resin-impregnated paper layers, and treating the layers under the influence of pressure and temperature. Preferably, the treatment of the layers comprises pressing at a pressure of 70 to 100 bar at a temperature of 140 to 160°C. The person skilled in the art understands that the above statements regarding the laminate according to the invention apply accordingly to the production method.For example, the manufacturing process may include a coating step to provide the shatter protection layer with a coating as described herein. Preferred embodiments.

[0031] The present invention is described in more detail below with reference to the accompanying figures. Like elements are provided with like reference numerals. The individual figures show:

[0032] Fig. i shows schematically the structure of a previously known laminate;

[0033] Fig. 2 schematically shows the structure of a laminate according to an embodiment;

[0034] Fig. 3 shows schematically the structure of a laminate according to a further embodiment;

[0035] Fig. 4 schematically shows the structure of a splinter protection layer according to another embodiment.

[0036] Fig. 2 shows a schematic view of the structure of a laminate according to one embodiment. The laminate comprises a first decorative paper 1 and a second decorative paper 2, each impregnated with melamine resin. Arranged between the decorative papers are a first number of phenol-impregnated paper layers 3a and a second number of phenol-impregnated paper layers 3b. In this embodiment, the structure is symmetrical, with the first number and the second number each being 5. Arranged between the first number of paper layers 3a and the second number of paper layers 3b is a 0.8 mm thick aluminum foil as a splinter protection layer 4, the aluminum foil being coated on both sides, for example with an adhesion promoter.

[0037] The splinter protection layer is pretreated in such a way that it can be pressed with impregnated paper to form a laminate. The paper can be impregnated with melamine or phenolic resins. In the final laminate, all layers must form a good bond to avoid delamination during later use. Pretreatment of the splinter protection layer can be carried out, for example, as follows: impregnation with resins, which is also used for impregnating the paper layers, or coating with an adhesion promoter (e.g., acrylate-based), or a treatment to activate the surface and thus improve the bond to the paper layers. Fig. 3 shows a schematic of the structure of a laminate according to another exemplary embodiment. The structure essentially corresponds to that shown in Fig.2, except that two splinter protection layers 4 are now provided, each arranged between paper layer arrangements 3a, 3b, 3c, which in this example also consist of five phenol-impregnated paper layers. One splinter protection layer 4 is arranged between the paper layer arrangements 3a and 3b, and a second splinter protection layer 4 is arranged between the paper layer arrangements 3b and 3c. The splinter protection layers 4 are identical to one another in this example and are each formed by a 0.8 mm thick aluminum foil.

[0038] Fig. 4 schematically shows the structure of a splinter protection layer 4 according to another embodiment. The splinter protection layer 4 is formed by a three-layer aluminum foil, with individual phenolic resin-impregnated paper layers 4b arranged between the individual aluminum layers 4a.

[0039] To evaluate the properties of the inventive laminate compared to conventional laminates, the laminates measuring 50 x 200 mm were clamped in a vice and broken with a hammer. While the conventional laminate broke and splintered during this treatment, the inventive laminate remained intact without forming dangerous splinters. Further comparative tests were conducted according to the EN438 standard, with particular emphasis on mechanical properties such as fracture strength and elastic modulus. Here, too, the inventive laminate proved particularly advantageous.

Claims

Claims 1. Laminate, in particular for use in interior trim elements of vehicles, comprising a first number of resin-impregnated paper layers (3a, 3b, 3c), a second number of resin-impregnated paper layers (3a, 3b, 3c), a splinter protection layer (4) between the first number of resin-impregnated paper layers (3a, 3b, 3c) and the second number of resin-impregnated paper layers (3a, 3b, 3c).

2. Laminate according to claim 1, wherein the first number and the second number are equal.

3. Laminate according to claim 1 or 2, wherein the splinter protection layer (4) comprises a metal foil.

4. Laminate according to claim 3, wherein the splinter protection layer (4) is an aluminum foil.

5. Laminate according to claim 3 or 4, wherein the splinter protection layer (4) comprises a multi-layer metal foil, wherein at least one resin-impregnated paper layer is arranged between the individual layers of the multi-layer metal foil.

6. Laminate according to one of claims 1-5, wherein the splinter protection layer (4) is coated on both sides.

7. Laminate according to one of claims 1-6, wherein the splinter protection layer (4) is coated with an adhesion promoter.

8. Laminate according to one of claims 1-7, wherein the splinter protection layer (4) has a thickness of 0.05-0.20 mm, preferably of 0.06-0.15 mm, more preferably of 0.07-0.10 mm, more preferably of about 0.08 mm. 9- Laminate according to one of claims 1-8, wherein the splinter protection layer (4) comprises glass fleece, PET, fabric, or carbon fibers.

10. Laminate according to one of claims 1-9, wherein the resin-impregnated paper layers (3a, 3b, 3c) are impregnated with formaldehyde resin.

11. Laminate according to one of claims 1-10, wherein the resin-impregnated paper layers (3a, 3b, 3c) contain 40-60 wt.% resin.

12. Laminate according to one of claims 1-11, wherein the resin-impregnated paper layers (3a, 3b, 3c) contain 5-7 wt.% volatile components.

13. Laminate according to one of claims 1-12, further comprising a first and a second melamine-impregnated decorative paper (1, 2), wherein the paper layers (3a, 3b, 3c) and the splinter protection layer (4) are arranged between the first and the second decorative paper (1, 2).

14. A method for producing a laminate, in particular for use in interior trim elements of vehicles, comprising Providing a first number of resin-impregnated paper layers (3a, 3b, 3c), Providing a second number of resin-impregnated paper layers (3a, 3b, 3c), Arranging a splinter protection layer (4) between the first number of resin-impregnated paper layers (3a, 3b, 3c) and the second number of resin-impregnated paper layers (3a, 3b, 3c), Treating the layers under the influence of pressure and temperature.

15. The method according to claim 14, wherein treating the layers comprises pressing at a pressure of 70-100 bar at a temperature of 140-160 °C.

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