Embossed and hot-melt laminated multilayer composite film

Abstract

A multi-layered composite film is provided that includes immediately consecutive and mutually bonded layers A-B-C: A: on the visible side, a polymer layer comprising 1 to 100% by weight of extrudable thermoplastic polyurethane-containing polymer and/or ionomer; B: a tie layer comprising one or more modified plastics for the tie; C: on the substrate side, a decorative layer;
wherein the layered composite is coextruded from the layers A and B and hot-melt laminated with the decorative substrate layer at a temperature above the fusion temperature of the layered composite, while simultaneously pattern(s) is/are plastically embossed on the visible side of the multi-layered composite film. The multi-layered composite films may be used as a floor covering, wall panelling or furniture film. A method for manufacturing the multi-layered composite films is also provided.

Claims

1. A multi-layered composite film, comprising at least the following immediately consecutive and mutually bonded layers A-B-C: A: on a visible side, a polymer layer comprising 1 to 100% by weight of extrudable thermoplastic polyurethane-containing polymer and/or ionomer; B: a tie layer comprising one or more modified plastics for the tie; C: on a substrate side, a decorative layer; characterised in that the layered composite of the layers A and B is coextruded and hot-melt laminated with the decorative layer at a temperature above the fusion temperature of the layered composite, while simultaneously one or more patterns is/are plastically embossed on the visible side of the multi-layered composite film in the same step; and characterised in that an embossing depth index I.sub.P is at least 6.0 once the multi-layered composite film has cooled to room temperature, and the embossing depth index I.sub.P is dimensionless and defined as follows (all values being in micrometers):
I.sub.P=R.sub.Z(visible side)1000/(R.sub.Z(substrate side)thickness(A-B-C)).

2. The multi-layered composite film according to claim 1, characterised in that the decorative layer comprises paper, plastic film or a combination of paper and plastic film which is printed on.

3. The multi-layered composite film according to claim 2, characterised in that the decorative layer C comprises a primer.

4. The multi-layered composite film according to claim 1, characterised in that the one or more embossed patterns is synchronized with the decorative layer.

5. The multi-layered composite film according to claim 1, characterised in that it contains no PVC or melamine resin.

6. The multi-layered composite film according to claim 1, characterised in that the polymer of the polymer layer A is an ionomer.

7. The multi-layered composite film according to claim 1, wherein the modified plastic(s) for the tie comprise(s) one or more polymer(s) modified with maleic anhydride, alkylated maleic anhydride and/or carboxylic acid.

8. The multi-layered composite film according to claim 1, characterised in that the decorative layer C contains an extrudable thermoplastic polymer selected from the group consisting of polyethylenes, polypropylenes and polybutylenes, polystyrene, polyamide, polyester and mixtures of the same.

9. The multi-layered composite film according to claim 1, characterised in that the polymer layer A exhibits a thickness in the range of 1 to 500; and/or the tie layer B exhibits a thickness in the range of 1 to 100 m; and/or the decorative layer C exhibits a thickness of 1 to 500 m.

10. The multi-layered composite film according to claim 1, characterised in that it comprises at least the consecutive and mutually bonded layers D-A-B-C, wherein the layer D denotes one or more mutually bonded layers and is connected to the layer A directly, via a bonding layer or adhesive layer, by lamination or by mechanical connecting elements.

11. The multi-layered composite film according to claim 10, characterised in that the layer D comprises one or more of the following layers: a covering layer, a UV protection layer, a moisture protection layer, a mechanical protection layer, a layer which prevents slipping, or a (heat-melt) adhesive layer, wherein the layer D can be transparent and/or can comprise a surface profile.

12. The use of a multi-layered composite film in accordance with claim 1, wherein the multi-layered composite film is used as a floor covering or in the manufacture of a floor covering, as wall panels or roof panels or in the manufacture of wall panels or roof panels, as furniture film.

13. A layered body comprising a multi-layered composite film in accordance with claim 1, wherein the multi-layered composite film is used as a floor covering or furniture film.

14. The floor covering according to claim 13, characterised in that it comprises at least one other layer E which is a substrate layer which adjoins the layer C and is connected to the layer C directly, via a bonding layer or adhesive layer, by lamination or by mechanical connecting elements.

15. The floor covering according to claim 14, characterised in that the substrate layer E comprises one of the following layers: a layer which prevents slipping, a heat-insulating layer, an impact sound-absorbing layer, a heat-conducting layer, an adhesive layer, a plywood layer or chipboard layer, a wood-plastic composite (WPC) layer and a fibre-reinforced concrete layer.

16. A method for manufacturing a multi-layered composite film according to claim 1, characterised in that the layered composite is coextruded from the layers A and B in a first step and hot-melt laminated with the decorative layer at a temperature above the fusion temperature of the layered composite in a second step, while simultaneously one or more patterns is/are plastically embossed on the visible side of the multi-layered composite film in the same step, wherein the temperature of the layered composite does not drop below the fusion temperature of the layered composite A-B between the first and second method steps.

17. The method according to claim 16, characterised in that the second method step is performed at a temperature of 150 to 300 C.

18. The multi-layered composite film according to claim 7, wherein the modified plastic(s) for the tie comprise(s) one or more copolymer(s) or grafted (co)polymers of monomers which support carboxylic acid functionality.

19. The multi-layered composite film according to claim 18, wherein the modified plastic(s) for the tie comprise(s) maleic anhydride and/or alkylated maleic anhydride with polypropylene, polyethylene, ethylene-vinyl acetate (EVA), ethylene-butyl acrylate (EBA), ethylene-acrylic acid (EAA), ethylene-methacrylic acid (EMAA), maleic acetate (MAH) and/or polyacrylate rubber (ACM).

20. The multi-layered composite film according to claim 9, characterised in that the polymer layer A exhibits a thickness in the range of 5 to 200 m; and/or the tie layer B exhibits a thickness in the range of 5 to 20 m; and/or the decorative layer C exhibits a thickness of 10 to 150 m.

21. The multi-layered composite film according to claim 20, wherein the tie layer B exhibits a thickness in the range of 6 to 10 m.

22. The use of a multi-layered composite film in accordance with claim 12, wherein the multi-layered composite film is used in the manufacture of a plywood board or chipboard and/or as a graphic film, or a printed graphic film.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) To assist those of ordinary skill in the art in making and using the disclosed assemblies, systems and methods, reference is made to the appended figures, wherein:

(2) FIG. 1 shows a cross-section of an embodiment of the multi-layered composite film of the invention which exhibits the layer design A-B-C.

(3) FIG. 2 shows a cross-section of another embodiment of the multi-layered composite film, for example as a floor covering which exhibits the layer design A-B-C-E.

(4) FIG. 3 shows a cross-section of another embodiment of the multi-layered composite film, for example as a furniture film which exhibits the layer design D-A-B-C.

(5) FIG. 4 shows a cross-section of another embodiment of the multi-layered composite film, for example as a furniture film which exhibits the layer design D-A-B-C-E.

(6) FIG. 5 shows a schematic and typical design of the method in accordance with the invention.

DETAILED DESCRIPTION OF DISCLOSURE

(7) The layered composite consisting of the layers A and B is coextruded at temperatures at which the polymers are fused. It is preferably coextruded at temperatures in the range of 100 to 400 C., particularly preferably in the range of 200 to 300 C. The following step of embossing and hot-melt laminating is performed as long as the coextruded layered composite is above the fusion temperature. Embossing and hot-melt laminating can typically be performed at temperatures above 200 C., in particular above 230 C., for example at at least 250 C., but advantageously below 280 C. or 260 C. Embossing and hot-melt laminating are advantageously performed in the same machine, temporally and spatially immediately following coextrusion.

(8) One advantage of the invention is that the layered composite A-B-C can be made largely without any solvent and/or adhesive. Ideally, the composite A-B-C does not contain any organic solvents and/or adhesives.

(9) Because embossing and hot-melt laminating are simultaneous, a realistic embossing depth can be achieved on the visible side of the multi-layered composite film, while the problem of raised embossment on the substrate side can be avoided completely or as far as possible. Since the coextruded layered composite A-B has not yet cooled and the embossment is to all intents and purposes made in the molten mass, there is no perceptible or only minimal relaxation after embossing. In accordance with the invention, it is surprisingly possible to avoid raised embossment as far as possible and to simultaneously achieve a high degree of wear resistance and low staining.

(10) The method is moreover highly economic, since an additional heating cycle for laminating is not required. The method in accordance with the invention also enables a reliable connection between the substrate, the decorative layer and the visible-side polymer layer containing thermoplastic polyurethane-containing polymer and/or ionomer. Laminating the soft material of the visible-side polymer layer, by contrast, involves great difficulties.

(11) The dimensionless embossing depth index I.sub.P represents one measure of raised embossment. It is calculated from the ratio of the embossing depth on the visible side to the raised embossment on the substrate side, each measured as an average surface roughness R.sub.Z (DIN EN ISO 4287:2010-07) divided by the thickness of the layered composite A-B-C, multiplied by 1000, all values being in micrometers:
I.sub.P=R.sub.Z(visible side)1000/(R.sub.Z(substrate side)thickness(A-B-C)).

(12) An embossing depth index of at least 6.0 after cooling is preferably achieved in accordance with the invention. For some applications, an embossing depth index of at least 8.0 or at least 9.5 or 10 to 20, preferably at least 13 or even more advantageously at least 14 or at least 16 can be achieved. Embossing depth indices of up to 30 or higher can be achieved in accordance with the invention.

(13) One advantage of a large embossing depth index is that the visible side can be embodied to be warm, soft, impact sound-absorbing and plastic and for example realistically imitates the tactile sensation and optical/aesthetic impression of coarse wood and coarse natural stone, while the surface of the layer on the substrate side can be kept as smooth and even as possible. This facilitates connecting it to a substrate E. The amount of adhesive required to connect it to a substrate E is for example minimised. The present invention additionally provides, for the first time, structural films which have no layer(s) of varnish or resin for additional visible-side protection but are nonetheless suitable for meeting the demands of wear resistance, chemical stability, scratch resistance, low staining, high durability and good resilience. The multi-layered composite film in accordance with the invention advantageously contains no PVC and/or melamine resin.

(14) In accordance with the invention, the decorative layer can comprise paper and/or plastic film which is printed on, wherein the plastic film can be monoaxially or biaxially orientated. Printing on film can be particularly preferable in accordance with the invention due to the increased brilliance. Casein-based printing inks (casein inks) are particularly preferred in accordance with the invention. The decorative pattern can be colourless, white, plain-coloured or coloured in some other way.

(15) In some cases, it can be expedient to apply a primer to the decorative layer, for example via a calender. This can improve the interconnection with the layered composite A-B, for example when casein printing inks are preferably used. The invention similarly relates to layered composites in accordance with the invention in which substrate-side decorative layer does not comprise a primer.

(16) The patterns embossed on in accordance with the invention are in principle unrestricted in terms of their embossing depth and design, although the maximum embossing depth is predetermined by the thickness of the layer, wherein the designs can be imitations of natural materials such as wood, stone, textiles, a stucco structure or any pattern which can be represented on a continuous roller. In accordance with the invention, the pattern embossed on can particularly advantageously be synchronised with the printed pattern, such that for example in the case of a wood imitation, the tactile sensation of the texture matches the optical impression. Embodying the respective pattern as a continuous and uninterrupted repetition further reinforces the true-to-nature impression.

(17) The polymer of the polymer layer A of the multi-layered composite film of the present invention can advantageously be selected from thermoplastic polyurethane or ionomer, for example Surlyn ionomer, or mixtures of the same, wherein it is advantageous if the polymer of the visible-side polymer layer A, for example an ionomer, is transparent and/or clear. The decorative pattern is preferably visible through the layers A and B.

(18) The modified plastic(s) for the tie can advantageously comprise one or more copolymer(s) or grafted (co)polymers of monomers which support carboxylic acid functionality, in particular maleic anhydride and/or alkylated maleic anhydride with polypropylene, polyethylene (for example LDPE or LLDPE), ethylene-vinyl acetate (EVA), ethylene-butyl acrylate (EBA), ethylene-ethyl acrylate (EEA), ethylene-acrylic acid (EAA), ethylene-methacrylic acid (EMAA), maleic acetate (MAH) and/or polyacrylate rubber (ACM).

(19) In one embodiment of the invention, the decorative layer C contains an extrudable thermoplastic polymer selected from the group consisting of polyethylenes, polypropylenes and polybutylenes, polystyrene, polyamide, polyester such as polyethylene terephthalate (PET) and mixtures of the same. One advantage of such decorative layers containing plastic film is their good printability, good process capability, their water resistance and their chemical stability.

(20) The polymer layer A typically, though not necessarily, exhibits a thickness in the range of 1 to 500 m, preferably 5 to 200 m; and/or

(21) the tie layer B typically, though not necessarily, exhibits a thickness in the range of 1 to 100 m, preferably 5 to 20 m, in particular 6 to 10 m; and/or

(22) the substrate layer C typically, though not necessarily, exhibits a thickness of 1 to 500 m, preferably 10 to 150 m.

(23) The multi-layered composite film of the present invention is also advantageously embodied such that it comprises at least the consecutive and mutually bonded layers D-A-B-C, wherein the layer D denotes one or more mutually bonded layers and is connected to the layer A directly, via a bonding layer or adhesive layer, by lamination or by mechanical connecting elements, wherein the layer D can for example have a thickness of 1 to 200 m, advantageously 10 to 100 m.

(24) The layer D can then advantageously comprise one or more of the following layers: one or more additional ionomer layers, a covering layer, a UV protection layer, a layer of varnish, a moisture protection layer, a mechanical protection layer, a layer which prevents slipping, or a (heat-melt) adhesive layer; wherein the layer D can be transparent and/or can comprise a surface profile.

(25) On the substrate side, the layer C can in accordance with the invention advantageously adjoin a substrate layer E which is connected to the layer C directly, via a bonding layer or adhesive layer, by lamination or by mechanical connecting elements.

(26) The layers A, B, C, D and E can in accordance with the invention contain no filler materials, effect materials and/or pigments. Conversely, in another embodiment of the invention, one or more of these layersfor example, the layers D and/or E, or the layers D and/or Acomprise filler materials, effect materials and/or pigments in an amount of 1 to 100% by weight. In one embodiment, the layered composite A-B-C or in particular the layer C contains no inorganic filler materials, effect materials and/or organic or inorganic pigments. In another embodiment, it is precisely the presence of such pigments or filler materials in one or more of the layers A-B-C which can provide for particular effects.

(27) The multi-layered composite film in accordance with the present invention can for example and ideally be used as a floor covering or in the manufacture of a floor covering, as wall panels or roof panels or in the manufacture of wall panels or roof panels, as furniture film, in particular in the manufacture of plywood board or chipboard and/or as a graphic film, in particular a printed film.

(28) The invention also therefore relates to a floor covering, wall panels and roof panels, a furniture film, plywood and chipboard and graphic film, in particular printed film, comprising a multi-layered composite film in accordance with the invention.

(29) A floor covering in accordance with the invention advantageously then comprises another layer E which is a substrate layer which adjoins the layer C and is connected to the layer C directly, via a bonding layer or adhesive layer, by lamination or by mechanical connecting elements, wherein the substrate layer E preferably comprises one of the following layers: a layer which prevents slipping, a heat-insulating layer, a sound-absorbing and in particular impact sound-absorbing layer, a heat-conducting layer, an adhesive layer, a plywood layer or chipboard layer, a wood-plastic composite (WPC) layer and a fibre-reinforced concrete layer.

(30) As described above, the invention similarly relates to a method for manufacturing a multi-layered composite film in accordance with the invention, characterised in that the layered composite of the layers A and B is coextruded in a first step and hot-melt laminated with the decorative substrate layer at a temperature above the fusion temperature of the layered composite in a second step, while simultaneously one or more patterns is/are plastically embossed on the visible side of the multi-layered composite film in the same step, wherein the temperature of the layered composite does not drop below the fusion temperature of the layered composite A-B between the first and second method steps.

(31) The second method step is then advantageously performed at a temperature of 150 to 300 C. As already stated, the method in accordance with the invention is preferably performed continuously. The embossment on the visible side is preferably synchronised with the decorative pattern printed on the decorative layer.

(32) Coextrusion is then performed in a conventional way under conditions which will be familiar to the person skilled in the art. The particular properties of the multi-layered composite films in accordance with the invention are achieved by performing the method steps of hot-melt laminating and embossing, which are known in their own right, simultaneously and without an additional heating cycle, in a continuous operation.

(33) FIG. 1 shows a cross-section of an embodiment of the multi-layered composite film of the invention which exhibits the layer design A-B-C. In this example, the layers are composed of:

(34) Layer A (100 m) ionomer;

(35) Layer B (8 m) maleic-anhydride-modified polyethylene as a modified plastic for the tie;

(36) Layer C (120 m) paper or plastic film which is printed on using casein ink and coated (10 m) with primer.

(37) FIG. 2 shows a cross-section of another embodiment of the multi-layered composite film, for example as a floor covering which exhibits the layer design A-B-C-E. In this example, the layers are composed of:

(38) Layer A (100 m) ionomer;

(39) Layer B (8 m) maleic-anhydride-modified polyethylene as a modified plastic for the tie;

(40) Layer C (120 m) paper or plastic film which is printed on using casein ink and coated (10 m) with primer;

(41) Layer E (2000 m) WPC.

(42) FIG. 3 shows a cross-section of another embodiment of the multi-layered composite film, for example as a furniture film which exhibits the layer design D-A-B-C. In this example, the layers are composed of:

(43) Layer D (50 m) varnish;

(44) Layer A (110 m) thermoplastic polyurethane;

(45) Layer B (5 m) maleic-anhydride-modified polyethylene as a modified plastic for the tie;

(46) Layer C (100 m) PET which is printed on using casein ink and coated (10 m) with primer.

(47) FIG. 4 shows a cross-section of another embodiment of the multi-layered composite film, for example as a furniture film which exhibits the layer design D-A-B-C-E. In this example, the layers are composed of:

(48) Layer D (80 m) ionomer;

(49) Layer A (120 m) ionomer;

(50) Layer B (10 m) maleic-anhydride-modified polyethylene as a modified plastic for the tie;

(51) Layer C (90 m) paper which is printed on using casein ink and coated (10 m) with primer;

(52) Layer E (1500 m) plywood layer, wood or for example fibre-reinforced concrete.

(53) FIG. 5 shows a schematic and typical design of the method in accordance with the invention, wherein a composite made of a layer A, which consists for example of ionomer, is coextruded in the nozzle 1 at a temperature of 200 to 280 C. with a (substrate-side) tie layer B as a molten mass 2 and then immediately connected on the substrate side, at the same temperature, to a layer of paper C/3 which is printed on and which is fed via a roller 4, for example a rubber roller. The layer C and the layered composite A-B are hot-melt laminated and simultaneously embossed on the visible side between the embossing roller 5 and the roller 4 at temperatures in the range of for example 150 to 300 C. simultaneously or immediately after they have been converged.

EXAMPLES

Example 1

(54) A multi-layered composite film exhibiting the following sequence of layers was manufactured according to the method in accordance with the invention, wherein the layers A and B were coextruded at 250 C. and then immediately hot-melt laminated with the layer of film C (which has a wood grain pattern printed on it in casein ink and is provided with primer) while still at 230 C. and at a pressing force of 30 kN, wherein a plastic wood-texture pattern was embossed on the visible side.

(55) Layer A (300 m) ionomer (Surlyn 1706 by Dupont);

(56) Layer B (10 m) maleic-anhydride-modified polyethylene as a modified plastic for the tie;

(57) Layer C (120 m) polypropylene film which is printed on using casein ink and coated (10 m) with primer.

(58) Table 1 lists some parameters for characterising the multi-layered composite film of Example 1.

(59) TABLE-US-00001 TABLE 1 Overall thickness A-B-C 431 m Embossing depth index I.sub.P (averaged from 14.1 two measurement values, dimensionless) Density 0.973 g/cm.sup.3 Grammage 4.189 g/100 cm.sup.2 Young's modulus, longitudinal 458 Mpa Young's modulus, transverse 406 Mpa Maximum force, longitudinal 177 N (6.47 SO mm.sup.2) Maximum force, transverse 159 N (6.47 SO mm.sup.2) Maximum elongation, longitudinal 246% Maximum elongation, transverse 201% Elongation at rupture, longitudinal 246% Elongation at rupture, transverse 201% Tensile strength, longitudinal 27 Mpa Tensile strength, transverse 25 Mpa Tearing strength, longitudinal 27 Mpa Tearing strength, transverse 25 Mpa Breaking force, longitudinal 175 N Breaking force, transverse 159 N (DIN EN ISO 527-3/1B/200) The average surface roughness R.sub.Z was determined using the MAHR perfometer.

Example 2

(60) A multi-layered composite film exhibiting each of the following sequences of layers was manufactured according to the method in accordance with the invention, wherein the layers A and B were coextruded at 250 C. and then immediately hot-melt laminated with a layer of paper C (which has a wood grain pattern printed on it in casein ink and is provided with 15 m of primer) while still at 230 C. and at a pressing force of 30 kN, wherein a plastic wood-texture pattern was embossed on the visible side.

(61) Film 2a

(62) Layer A (50 m) ionomer (Surlyn 1706 by Dupont de Nemours);

(63) Layer B (10 m) maleic-anhydride-modified polyethylene as a modified plastic for the tie;

(64) Layer C (105 m) decorative paper which is printed on using casein ink and coated (15 m) with primer.

(65) Overall thickness A-B-C: 165 m

(66) Film 2b

(67) Layer A (250 m) ionomer (Surlyn 1706 by Dupont de Nemours);

(68) Layer B (10 m) maleic-anhydride-modified polyethylene as a modified plastic for the tie;

(69) Layer C (105 m) decorative paper which is printed on using casein ink and coated (15 m) with primer.

(70) Overall thickness A-B-C: 365 m

(71) The layered composite films were laminated with chipboard/hot-melt adhesion and tested for scratch resistance (DIN 438-2), abrasion resistance, wear resistance (DIN EN 13329) and resistance to staining (DIN 438-2), wherein the layered composites in accordance with the invention exhibit good to very good results throughout.