Multi-layer, substantially polyvinyl chloride- and polyolefin-free composite film

Abstract

The invention relates to a multilayer composite foil substantially free from polyvinyl chloride and polyolefins, more particularly a furniture foil, comprising ABS, especially ABS with admixtures, and/or polystyrene, especially polystyrene with admixtures and/or high shock-resistant polystyrene, and/or polyester, especially amorphous polyester copolymer, wherein a maximum tensile force ranging between 30 and 280 Newton is attained during a uniaxial tensile test of one test body consisting of the composite foil, wherein the uniaxial tensile test complies with special test regulations.

Description

The present invention concerns a multi-layer, substantially polyvinyl chloride- and polyolefin-free composite film, in particular furniture film, comprising at least one carrier layer which has ABS, in particular ABS with admixtures, and/or polystyrene, in particular polystyrene with admixtures and/or high-impact polystyrene, and/or polyester, in particular amorphous polyester copolymer.

When using thermoplastic decorative films in the furniture sector, particularly when high-shine surfaces are involved, high demands are made in terms of scratch resistance, abrasion resistance, chemical resistance, tension tearing resistance and optical values such as shine, long- and short-wave factors as well as surface fine roughness. Environmental awareness is also increasingly advancing into the furniture sector, so that demands are also additionally being made in terms of the material nature of the thermoplastic films. The materials and processes used at the present time do not always satisfy those conditions.

Furniture films of thermoplastic materials are produced for example by lamination/coating of a thin scratch-resistant layer on to a pigmented polyvinyl chloride (PVC) carrier film and subsequent application of a primer layer at the rear side. Admittedly, PVC carrier films substantially satisfy all physical and optical requirements as are made in respect of furniture films, but on the other hand nowadays they are deemed to be ecologically questionable. A more ecologically advantageous variant was marketed, using a base film of pigmented amorphous polyester copolymer, instead of the pigmented PVC base film. Further alternatives on a polyolefinic carrier basis are described in EP 0 987 102 A2, which contains a base of polyethylene and, besides the scratch-resistant coating, also an overlay film of transparent amorphous polyester copolymer. In addition, EP 0 704 482 B1 defines a plurality of structures in which polyolefins are homogenised with polymers of other chemical classes (styrene copolymers, polymethacrylates) and processed to constitute films for furniture and articles of furniture. EP 0 875 374 A2 describes a product for which a carrier film comprising polyolefins, ABS (=acrylonitrile-butadiene-styrene copolymers), ASA (=acrylonitrile-styrene-acrylic ester copolymers), AES (=thermoplastic quadrupolymer of acrylonitrile-ethylene-propylene-styrene), PET (=polyethylene terephthalate) or an amorphous polyester is laminated with an overlay film of an amorphous polyester. Japanese specification No 08311301 A describes an ABS film to which a defined addition of polycaprolactone is added as a processing aid for the calendering process. In addition it may also contain between 5 and 50 percent by weight of methacrylate raw material.

Co-extruded panels of polymethylmethacrylate (PMMA) and ABS are also known as high-shine film materials. The furniture films are produced in that case by co-extrusion by way of a wide-slot nozzle. An alternative form of processing represents thermoshaping of those films with subsequent adhesion thereof to wood fibre panels. A further alternative form of processing is represented by glueing on to flat surfaces and hot edging. In general terms, processing of the thermoplastic, high-shine furniture films and mats is effected by way of pressing, laminating or shaping on wood or foam cores. In order to be able to process the films on the existing machines the films must satisfy defined technical conditions. Thus in particular inter alia they must enjoy good thermoshapability at low temperatures (100° C.) and a corresponding processing window of between 90 and 120° C. In addition the film should have improved surface properties (shine, long wave, short wave, UV—(=ultraviolet light)resistance, scratch resistance, chemical resistance) as well as good adhesion properties to wood materials, pieces of wood or foam cores. Those demands are only partially or not at all fulfilled by the PVC-free films in the state of the art, which are the aim from an ecological point of view.

Therefore the object of the invention is to provide a composite film which on the one hand affords an ecologically appropriate alternative, which has defined surface qualities, to the PVC-based films substantially used hitherto in the state of the art, and which on the other hand satisfies the above-specified technical requirements.

In accordance with the invention that is achieved in that, in the single-axis tensile testing of a test body comprising the composite film, a maximum tensile force of between 30 Newtons and 280 Newtons occurs, wherein the single-axis tensile testing procedure satisfies the following testing specification:

a) a test body in accordance with type 1 B as set forth in ISO 527-2:1996 (incorporated by reference) Section 6 of a thickness which corresponds to the thickness of the composite film to be tested is stored prior to the beginning of the test for 24 hours at 23° C. and 50% relative air humidity;

b) the step of clamping the test body pretreated in that way into a testing apparatus in accordance with ISO 527-1:1996 (incorporated by reference) Section 5 is then effected, wherein the longitudinal axis of the test body is parallel to the composite film extrusion or calendering direction, and the prestressing is applied in accordance with ISO 527-1:1996 Sections 9.2 and 9.5;

c) subsequent implementation of the single-axis tensile test is effected in accordance with ISO 527-1:1996 at a constant testing speed of 800 mm/min and at a constant temperature of 80° C., wherein immediately prior in time to the beginning of implementation of the tensile test the clamped test body remains in a climatic chamber temperature-controlled at 80° C. for a period of 10 minutes, and

d) during the implementation of the tensile test recording of the tensile forces which occur is effected in dependence on the test time from the beginning of the testing procedure in a range of nominal stretch ε_t (in accordance with ISO 527-1:1996 Section 10.2) of between 0% and 100%.

Besides the above-specified surface properties, it is particularly important in regard to the composite films according to the invention that they satisfy the criteria in respect of thermoshapability in the above-stated temperature ranges. Thermoshapability of the composite films is an aspect of central significance for the subsequent use thereof in the furniture industry as furniture films. In this respect the term thermoshapability is used in particular to mean that the composite films, with processes in accordance with the state of the art, can be precisely matched to the surface configuration of the item of furniture to be coated. Critical locations when applying such composite films are in particular corners, edges, recesses and so forth in the item of furniture. In that respect it is crucial that the composite films can also be adapted as exactly as possible to small corners, radii and edges.

In that respect it was found in accordance with the invention that those films which satisfy a single-axis tensile testing procedure as is set forth in the characterising portion of claim 1 and set out in greater detail hereinafter have the required properties in respect of thermoshapability. It is important in regard to the tensile testing that the test body is not pre-loaded prior to executing the tensile testing procedure according to the invention.

In the preferred embodiments it is provided that the carrier layer of the composite film is of a thickness of between 100 and 1000 μm. Composite films according to the invention in that range of thicknesses can be well processed. In addition they have the thickness necessary in regard to the quality requirements.

Particularly advantageous alternative configurations of the composite films provide that they have at least one carrier layer with amorphous polyester copolymer, wherein, in the single-axis tensile testing of such a composite film, a maximum tensile force of between 50 Newtons and 120 Newtons, preferably between 65 Newtons and 105 Newtons, occurs. It is advantageous with those films for the film to be of a thickness of between 200 and 600 μm, preferably between 300 and 450 μm. Another advantageous group of composite films provides that they have at least one carrier layer with ABS and/or polystyrene, preferably HIPS (high impact polystyrene), wherein in the single-axis tensile testing of such a composite film a maximum tensile force of between 50 Newtons and 230 Newtons, preferably between 105 Newtons and 230 Newtons, occurs. It is particularly desirable in that respect that, in the tensile testing of such a composite film, a maximum tensile force of between 105 Newtons and 180 Newtons occurs. In addition it is provided that those composite films are of a thickness of between 400 and 1000 μm, preferably between 600 and 800 μm.

Particularly preferred variants of the composite film have at least one carrier layer of ABS, in particular in ABS with admixtures and/or polystyrene, in particular polystyrene with admixtures and/or high impact polystyrene, and/or polyesters, in particular amorphous polyester copolymer. It is provided in that respect that the composite film, under a cover layer, has a single-layer extrudate or an at least double-layer co-extrudate, as the carrier layer. That represents a basic structure of the films according to the invention, which particularly well enjoys the properties required in the above-described test.

Preferred embodiments provide that at least one carrier layer of the composite film have UV-stabilisers and/or UV-absorbers and/or pigments, preferably for coloration purposes, and in a proportion by volume of between 0.1 and 10%. By virtue of that addition, the film attains its desired optical properties and also retains them even if it is exposed to sunlight over many years.

Preferred embodiments further provide that the carrier layer and/or at least one layer of the carrier layer have additives for Vicat reduction, with a proportion by weight of between 1 and 70%. A variant provides that the carrier layer and/or at least one layer of the carrier layer have polycaprolactone with a proportion by weight of between 0.5 and 15%. A further variant provides that the carrier layer and/or at least one layer of the carrier layer have amorphous polyester copolymer with a proportion by weight of between 30 and 70%. Those additives serve in particular to provide the composite film with superior physical properties.

In the case of a multilayer and preferably a double-layer structure of the co-extrudate of the carrier layer a preferred embodiment provides that in at least one layer—preferably facing away from the cover layer—the carrier layer has recycled material from the ongoing production process.

A primer layer can be applied to the side of the carrier layer, which is in opposite relationship to the cover layer of the composite film. The primer layer serves to connect the composite film to the body to which it is applied.

Preferred embodiments provide that, in the case of its single-layer structure, the carrier layer is of a thickness of between 94 and 98% of the overall thickness of the composite film.

Furthermore, preferred embodiments provide that the cover layer of the composite film is co-extruded together with the carrier layer and has PMMA or impact-resistant modified PMMA. A selected group of composite films according to the invention provides that the composite film is of an overall thickness of between 500 and 1000 μm, preferably between 500 and 800 μm. In addition it is provided in selected embodiments that the cover layer of the composite film is of a layer thickness of between 1 and 5%, preferably in the range of between 3 and 4%, of the overall thickness of the composite film.

In addition it is provided in selected embodiments that, in the case of a double-layer carrier layer, the first layer thereof is of a thickness of between 5 and 20%, preferably between 10 and 15%, of the overall thickness of the composite film, and the second layer of the carrier layer is of a thickness of between 74 and 93%, preferably between 75 and 85%, of the overall thickness of the composite film.

Other embodiments provide that, as the cover layer, a transparent scratch-resistant coating is laminated on to the carrier layer or applied by thermal transfer printing. In regard to this group of the composite films according to the invention it is provided that the composite film is of an overall thickness of between 200 and 600 μm, preferably between 300 and 450 μm. In comparison with the composite films in which the cover layer of the composite film is co-extruded together with the carrier layer in a co-extrusion process, it is thus possible here to achieve a thinner overall thickness for the composite film if the cover layer is applied by lamination.

In these embodiments it is further provided that the cover layer of the composite film is of a layer thickness of between 1 and 5%, preferably between 1 and 3%, of the overall thickness of the composite film.

Preferred embodiments provide in this respect that, in the case of a double-layer carrier layer, the first layer thereof is of a thickness of between 20 and 40%, preferably between 25 and 35% of the overall thickness of the composite film and the second layer of the carrier layer is of a thickness of between 60 and 75%, preferably between 65 and 70% of the overall thickness of the composite film.

Other preferred embodiments provide that a transparent scratch-resistant coating is applied to the carrier layer by printing or lacquering, as the cover layer. In that case the composite films are of an overall thickness of between 200 and 600 μm, preferably between 300 and 450 μm. These embodiments further provide that the cover layer of the composite film is of a layer thickness of between 1 and 5%, preferably between 1 and 3%, of the overall thickness of the composite film.

In the case of a double-layer carrier layer of the composite film, selected embodiments provide that the first layer thereof is of a thickness of between 20 and 40%, preferably between 25 and 35%, of the overall thickness of the composite film, and the second layer of the carrier layer is of a thickness of between 60 and 75%, preferably between 65 and 70%, of the overall layer of the composite film.

A select embodiment provides moreover that the carrier layer has an additional co-extruded layer facing towards the primer layer, the additional layer preferably comprising amorphous polyester copolymer with anti-blocking additive.

Another preferred embodiment provides that the cover layer is of a multi-layer structure and is laminated in the form of a ready pre-product on to the carrier layer. In that respect it is preferably provided that the cover layer has four layers, wherein the first layer is a transparent scratch-resistant coating, preferably with UV-stabilisers and/or UV-absorbers, the second layer is a transparent overlay film comprising amorphous polyester copolymer, preferably with UV-stabilisers and/or UV-absorbers, the third layer is a decorative layer and the fourth layer is a primer layer. It is provided in these films in accordance with the invention that the composite film is of an overall thickness of between 200 and 600 μm, preferably between 300 and 450 μm. In addition embodiments according to the invention in that respect provide that the cover layer is of a thickness of between 30 and 40%, preferably between 33 and 37%, of the overall thickness of the composite film.

Other embodiments according to the invention provide that the side of the carrier layer, which is opposite to the decorative layer, has at least one decorative layer and/or at least one colour cover layer and/or at least one primer layer, wherein preferably the cover layer has a transparent scratch-resistant coating with UV-stabilisers and/or UV-absorbers. It is provided in those preferred embodiments that the co-extruded carrier layer is at least 80% and preferably 95% of the overall thickness of the composite film. In addition it is provided in preferred embodiments that the first layer of the carrier layer is chemically and/or mechanically matted.

Further embodiments provide that the carrier layer is transparent. Preferred embodiments further provide that the decorative and/or colour cover layer or layers is or are applied to the carrier layer using copper intaglio printing and/or flexographic printing and/or screen printing and/or offset printing. By virtue of the application of the decorative layers or colour cover layers on the side of the carrier layer, which after application of the composite film to the article of furniture faces towards the article of furniture, the decorative or colour cover layers is or are particularly well protected by the carrier layer from abrasion and damage in use of the article of furniture.

Further features and details of the present invention will be apparent from the specific description hereinafter.

In the drawing:

FIG. 1 is a diagrammatic view relating to the testing process for composite films according to the invention, and

FIGS. 2 through 5 show embodiments according to the invention of various composite films.

The testing process diagrammatically shown in FIG. 1 serves to determine the deformation characteristics of co-extruded composite films in a single-axis tensile testing procedure for determining the deformability of those films for example on diaphragm pressing installations (=a type of installation often used in the processing of composite films).

In accordance with the invention a tensile testing operation is effected in accordance with ISO 527-1:1996 at a defined testing temperature at a constant testing speed. In this respect the variation in the testing tensile force which is necessary to maintain the constant testing speed throughout the entire duration of the testing procedure is recorded in dependence on the testing time. The tensile force which occurs at a maximum during the tensile testing procedure serves as a criterion in regard to the deformability of the films on diaphragm pressing installations.

FIG. 1 diagrammatically shows the test body 21 which is clamped between the gripping clamps 22 and 23 and pulled in the direction 26 at a constant speed with a pulling device 25 and thereby stretched. The tensile forces which occur in that case at the test body are recorded by means of a force measuring device 24 in dependence on time. The nominal stretch is measured by suitable means (not shown here) in accordance with ISO 527-1:1996.

The testing apparatus which is used for the deformation tests must satisfy the conditions defined in ISO 527-1:1996 Section 5.

A test body of type 1B in accordance with ISO 527-2:1996 Section 6 is used for the tensile testing operations. The removal of the test bodies from the composite film to be tested should be effected in such a way that the longitudinal axis of the test body is parallel to the extrusion direction or calendering direction. Production of the test bodies must be effected by milling of the films by means of a suitable milling template. The edges of the milled test bodies must be free from tears or milling burrs. If required the milled test bodies must be fine-ground at the edges while still in the template by means of abrasive paper (international grain size 220).

As a certain scatter in respect of the measurement values is to be expected in any measuring or testing procedure, implementation of the tensile testing is to be carried out on a plurality of test bodies from one and the same composite film, in which case the arithmetic mean must be in the value range according to the invention, having regard to the standard deviation.

The choice of the number of test bodies is based on ISO 527-1:1996 Section 7.1, that testing specification requiring only one testing direction (parallel to the extrusion direction).

Based on ISO 527-1:1996 Sections 7.2 and 7.3 test bodies which break in the shoulder region or which stretch out of shape into the shoulder region must be rejected. Test bodies which have slipped out of the gripping clamp or in which an obvious fault has resulted in premature failure may also not be included in the evaluation. Repetition tests with a corresponding number of new test bodies have to be carried out.

Before carrying out the tensile testing operation, based on ISO 291 (incorporated by reference) (‘Plastic materials normal climates for conditioning and testing’) the test bodies are stored for 24 hours at 23° C. room temperature and a relative air humidity of 50%.

Implementation of the test according to the invention is effected at elevated temperature T₁=80° C. For that purpose the testing apparatus must be provided with a suitable climate chamber. The test bodies pre-treated as described above are clamped in the testing apparatus and heated for 10 minutes in the climate chamber which is temperature-controlled at 80° C. After the expiry of that period of time the tensile testing procedure is started.

The dimensions of the test bodies, the clamping of the test bodies and the application of the prestressing are effected in accordance with ISO 527-1:1996 Sections 9.2 through 9.5.

The tensile testing operation is effected in a speed-controlled mode at a testing speed of 800 mm/min, which is constant for the duration of the tensile testing operation.

With this testing method, the tensile force which currently applies at any moment in time is variable and, after application of the constant testing speed, arises out of the resistance to stretch, which is variable in respect of time, of the test body.

Evaluation and representation of the test results are effected in accordance with ISO 527-1:1996 Section 10.

It is possible to use both stress-stretch diagrams (see ISO 527-1:1996 FIG. 1) and also tensile force/stretch diagrams, for evaluating the tensile test. The relationship between tensile stress and tensile force can be found from ISO 527-1:1996 Section 10.1.

Evaluation of the tensile test is effected within a stretch range of between 0% and 100%, in that case the nominal stretch ε_t of the test body, as defined in ISO 527-1:1996 Section 10.2, is used.

The test report may contain all information which is set forth in ISO 527-1:1996 Section 12.

Accordingly the test bodies which were taken from the films corresponding to this patent must have a maximally occurring tensile force which is at least in the range of between 30 and 280 Newtons (N) in the above-described tensile test within a nominal stretch range of between 0 and 100%. A further subdivision of the required tensile force range for specific film types is specified hereinbefore.

FIG. 2 shows a diagrammatic view of the layer structure of the embodiments of the composite film A1 through A7.

The specific layer structure of these embodiments and the percentage thickness proportions of the layers 1 through 4 and additives in the individual layers and remarks on the layers are to be found in the listing set forth hereinafter:

A1 - Co-extrudate - overall thickness 0.75 mm
Layer 1 - thickness: 4%  PMMA + preferably 0.1-3% pigments for
                         colouring + UV stabilisation preferably comprising
                         UV-stabilisers and/or UV-absorbers
or:                      PMMA + UV stabilisation
layer 2 - thickness: 15% ABS + 0.5-10% pigments for colouring + optionally UV stabilisation
or:                      ABS + 0.5-10% pigments + optionally UV
                         stabilisation + optionally additive for Vicat
                         reduction: 10% polycaprolactone or 50% amorphous polyester
                         copolymer
layer 3 - thickness: 80% ABS + 0.5-10% pigments for colouring
or:                      ABS + 0.5-10% pigments + additive for Vicat
                         reduction; 10% polycaprolactone or 50%
                         amorphous polyester copolymer + recycled
                         material from ongoing production process
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layers 2 and 3 are the carrier layer
                         the layers 1 through 3 are produced in the co-
                         extrusion process
                         layer 1 is the cover layer
                         in layer 1 both impact-modified and also
                         standard PMMA can be used
                         the layer 2 can be omitted but is generally
                         produced.
A2 - Co-extrudate - overall thickness 0.75 mm
Layer 1 - thickness: 4%  PMMA + 0.1-3% pigments for colouring + UV
                         stabilisation preferably comprising UV-stabilisers
                         and/or UV-absorbers
or:                      PMMA + UV stabilisation
layer 2 - thickness: 15% HIPS (=high impact polystyrene) + 0.5-10%
                         pigments for colouring + optionally UV
                         stabilisation
or:                      HIPS + 0.5-10% pigments + optionally UV
                         stabilisation + optionally additive for Vicat
                         reduction: 2% polycaprolactone or 50%
                         amorphous polyester copolymer
layer 3 - thickness: 80% HIPS + 0.5-10% pigments for colouring + recycled
                         material from the ongoing production
                         process
or:                      HIPS + 0.5-10% pigments + additive for Vicat
                         reduction; 2% polycaprolactone or 50%
                         amorphous polyester copolymer + recycled
                         material from ongoing production process
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layers 2 and 3 are the carrier layer
                         the layers 1 through 3 are produced in the co-
                         extrusion process
                         layer 1 is the cover layer
                         in layer 1 both impact-modified and also
                         standard PMMA can be used
                         the layer 2 can be omitted but is generally
                         produced.
A3 - Co-extrudate - overall thickness 0.75 mm
Layer 1 - thickness: 4%  PMMA + 0.1-3% pigments for colouring + UV
                         stabilisation preferably comprising UV-stabilisers
                         and/or UV-absorbers
or:                      PMMA + UV stabilisation
layer 2 - thickness: 15% amorphous polyester copolymer + 0.5-10%
                         pigments for colouring + optionally UV
                         stabilisation
layer 3 - thickness: 80% amorphous polyester copolymer + 0.5-10%
                         pigments for colouring + recycled material from
                         ongoing production process
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layers 2 and 3 are the carrier layer
                         the layers 1 through 3 are produced in the co-
                         extrusion process
                         layer 1 is the cover layer
                         in layer 1 both impact-modified and also
                         standard PMMA can be used
                         the layer 2 can be omitted but is generally
                         produced.
A4 - Laminate - overall thickness 0.40 mm
Layer 1 - thickness: 2%  Transparent scratch-resistant coating + optionally
                         UV stabilisation
layer 2 - thickness: 30% ABS + 0.5-10% pigments for colouring + optionally
                         UV stabilisation
or:                      ABS + 0.5-10% pigments + optionally UV
                         stabilisation + optionally additive for Vicat
                         reduction: 10% polycaprolactone or 50%
                         amorphous polyester copolymer
layer 3 - thickness: 67% ABS + 0.5-10% pigments for colouring
or:                      ABS + 0.5-10% pigments + additive for Vicat
                         reduction; 10% polycaprolactone or 50%
                         amorphous polyester copolymer + recycled
                         material from ongoing production process
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layer 1 is applied inline or exline by
                         lamination or thermal transfer printing
                         the layers 2-3 are produced in the co-extrusion
                         process and are the carrier layer
                         the layer 2 can be omitted but is generally
                         produced.
A5 - Laminate - overall thickness 0.40 mm
Layer 1 - thickness: 2%  Transparent scratch-resistant coating + optionally
                         UV stabilisation
layer 2 - thickness: 30% HIPS + 0.5-10% pigments for colouring + optionally
                         UV stabilisation
or:                      HIPS + 0.5-10% pigments + optionally UV
                         stabilisation + optionally additive for Vicat
                         reduction: 2% polycaprolactone or 50%
                         amorphous polyester copolymer
layer 3 - thickness: 67% HIPS + 0.5-10% pigments for colouring
or:                      HIPS + 0.5-10% pigments + additive for Vicat
                         reduction; 2% polycaprolactone or 50%
                         amorphous polyester copolymer + recycled
                         material from ongoing production process
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layer 1 is applied inline or exline by
                         lamination or thermal transfer printing
                         the layers 2-3 are produced in the co-extrusion
                         process and are the carrier layer
                         the layer 2 can be omitted but is generally
                         produced.
A6 - Lacquering - overall thickness 0.40 mm
Layer 1 - thickness: 2%  Transparent scratch-resistant coating + optionally
                         UV stabilisation
layer 2 - thickness: 30% ABS + 0.5-10% pigments for colouring + optionally
                         UV stabilisation
or:                      ABS + 0.5-10% pigments + optionally UV
                         stabilisation, additive for Vicat reduction: 10%
                         polycaprolactone or 50% amorphous polyester
                         copolymer
layer 3 - thickness: 67% ABS + 0.5-10% pigments for colouring
or:                      ABS + 0.5-10% pigments + additive for Vicat
                         reduction; 10% polycaprolactone or 50%
                         amorphous polyester copolymer + recycled
                         material from ongoing production process
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layer 1 is applied by printing or lacquering
                         the layers 2-3 are produced in the co-extrusion
                         process and are the carrier layer
                         the layer 2 can be omitted but is generally
                         produced.
A7 - Lacquering - overall thickness 0.40 mm
Layer 1 - thickness: 2%  Transparent scratch-resistant coating + optionally
                         UV stabilisation
layer 2 - thickness: 30% HIPS + 0.5-10% pigments for colouring + optionally
                         UV stabilisation
or:                      HIPS + 0.5-10% pigments + optionally UV
                         stabilisation + additive for Vicat reduction: 2%
                         polycaprolactone or 50% amorphous polyester
                         copolymer
layer 3 - thickness: 67% HIPS + 0.5-10% pigments for colouring
or:                      HIPS + 0.5-10% pigments + additive for Vicat
                         reduction; 2% polycaprolactone or 50%
                         amorphous polyester copolymer + recycled
                         material from ongoing production process
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layer 1 is applied by printing or lacquering
                         the layers 2-3 are produced in the co-extrusion
                         process and are the carrier layer
                         the layer 2 can be omitted but is generally
                         produced.

FIG. 3 shows a composite film according to the invention in which the carrier layer is of a triple-layer structure. The precise layer structure is for example as follows:

A8 - Laminate - overall thickness 0.40 mm
Layer 1 - thickness: 2%  Transparent scratch-resistant coating +
                         optionally UV stabilisation
                         (preferably comprising UV-
                         stabilisers and/or UV-absorber)
layer 2 - thickness: 10% amorphous polyester copolymer + 0.5-10%
                         pigments for colouring + optionally UV
                         stabilisation (preferably comprising UV-
                         stabilisers and/or US-absorber) +
                         optionally anti-
                         blocking additive
layer 3 - thickness: 85% amorphous polyester copolymer + 0.5-10%
                         pigments for colouring +
                         recycled material from
                         ongoing production process
layer 5 - thickness: 2%  amorphous polyester
                         copolymer + anti-blocking
                         additive
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layer 1 is applied inline or exline by
                         lamination or thermal transfer printing
                         the layers 2, 3 and 5 are produced in the co-
                         extrusion process and are the carrier layer.

FIG. 4 shows the structure of a composite film according to the invention in which the cover layer is of a multi-layer structure. The precise layer structure is for example as follows:

A9 - Laminate - overall thickness 0.40 mm
Layer 6 - thickness: 2%  Transparent scratch-resistant
                         coating + optionally
                         UV stabilisation
layer 7 - thickness: 30% transparent overlay film comprising amorphous
                         polyester copolymer +
                         optionally UV-stabilisation
layer 8 - thickness: 1%  decorative layer
layer 9 - thickness: 1%  primer (applied by printing)
layer 2 - thickness: 20% HIPS + 0.5-10% pigments
                         for colouring + optionally
                         UV stabilisation
or:                      HIPS + 0.5-10% pigments + optionally UV
                         stabilisation + additive for Vicat reduction: 2%
                         polycaprolactone or 50% amorphous polyester
                         copolymer
layer 3 - thickness: 45% HIPS + 0.5-10% pigments for colouring
or:                      HIPS + 0.5-10% pigments + additive for Vicat
                         reduction; 2% polycaprolactone or 50%
                         amorphous polyester copolymer + recycled
                         material from ongoing production process
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layer 6 is applied by printing or
                         lacquering to the layer 7
                         the layer 7 can be chemically or mechanically
                         matted, it is produced using an extrusion
                         process layers 8 and 9
                         are applied to the layer 7 by
                         copper intaglio, flexographic, screen or offset
                         printing
                         the layers 2-3 are produced in the co-extrusion
                         process and are the carrier layer
                         the layer 2 can be omitted but is generally
                         produced
                         the overall structure is afforded by
                         lamination or a pressing operation
                         of the intermediate product
                         of layers 6-9 (=pre-product)
                         with the previously
                         co-extruded intermediate product
                         consisting of the
                         layers 2 and 3
                         the layer 4 is applied to the overall laminate by
                         printing.

FIG. 5 shows a composite film according to the invention whose main characteristic is that the decorative layers are applied between the carrier layer and the primer layer, under the carrier layer. The precise layer structure in that respect is for example as follows:

A10 - Lacquering - overall thickness 0.40 mm
Layer 1 - thickness: 2%  Transparent scratch-resistant
                         coating + optionally
                         UV stabilisation (preferably comprising UV-
                         stabilisers and/or UV-absorber);
                         (high shine-matt)
layer 10 - thickness:    amorphous polyester
10%                      copolymer + anti-blocking
                         additive + optionally UV
                         stabilisation (preferably
                         comprising UV-stabilisers and/or UV-absorber)
layer 11 - thickness:    amorphous polyester copolymer + recycled
83%                      material from ongoing production process
layer 12 - thickness: 2% amorphous polyester
                         copolymer + anti-blocking
                         additive
layer 13 - thickness: 1% decorative layer (for example wood fibre)
layer 14 - thickness: 1% colour cover layer (for example wood brown)
layer 4 - thickness: 1%  primer (applied by printing).
Remarks:                 the layer 10 can be chemically or mechanically
                         matted, it is produced using
                         an extrusion process
                         the layers 10-12 are produced in the co-
                         extrusion process and are the carrier layer
                         layers 13 and 14 are
                         applied by copper intaglio,
                         flexographic, screen or offset printing.

The materials shown in the various embodiments in FIGS. 2 through 5 involve the following material characteristics:

1. PMMA: polymethylmethacrylate

• • impact-resistance modifier content: 0-30% by weight, preferably 0-15%
  • E-modulus tension in accordance with ISO 527;1800-3400 MPa, preferably 2500-3300 MPa
  • Vicat softening temperature, ° C., ISO 306 (incorporated by reference) (50° C./h 50N); 90-109° C., preferably 100-109° C.

2. ABS: acrylonitrile-butadiene-styrene copolymer

• • melt flow rate MFR (ISO 1133 (incorporated by reference) (220° C./10 kg) in g/10 min, between 3.5 and 8, preferably between 4.0 and 6.5
  • E-modulus tension in accordance with ISO 527;1400-2300 MPa,
  • Vicat softening temperature, ° C., ISO 306 (50° C./h 50N); 90-103° C., preferably 99-101° C.

3. HIPS: polystyrene impact modified (high impact)

• • melt flow rate MFR (ISO 1133 (220° C./10 kg) in g/10 min, between 3.5 and 6.5
  • E-modulus tension in accordance with ISO 527;1100-2100 MPa,
  • acrylonitrile proportion of 4-12%
  • Vicat softening temperature, ° C., ISO 306 (50° C./h); 82-93° C., preferably 90-93° C.

4. Amorphous polyester copolymer:

• • E-modulus tension in accordance with ISO 527:1600-2400 MPa
  • Vicat softening temperature, ° C., ISO 306:80-90° C., preferably 85° C.

Claims

1. A multi-layer, substantially polyvinyl chloride- and polyolefin-free composite film, comprising at least one carrier layer which has ABS or polystyrene or polyester, characterised in that in the single-axis tensile testing of a test body comprising the composite film, a maximum tensile force of between 30 Newtons and 280 Newtons occurs, wherein the single-axis tensile testing procedure satisfies the following testing specification (FIG. 1):

a) a test body in accordance with type 1 B as set forth in ISO 527-2:1996 Section 6 of a thickness which corresponds to the thickness of the composite film to be tested is stored prior to the beginning of the test for 24 hours at 23° C. and 50% relative air humidity;

b) the step of clamping the test body pretreated in that way into a testing apparatus in accordance with ISO 527-1:1996 Section 5 is then effected, wherein the longitudinal axis of the test body is parallel to the composite film extrusion or calendering direction, and the prestressing is applied in accordance with ISO 527-1:1996 Sections 9.2 and 9.5;

c) subsequent implementation of the single-axis tensile test is effected in accordance with ISO 527-1:1996 at a constant testing speed of 800 mm/min and at a constant temperature of 80° C., wherein immediately prior in time to the beginning of implementation of the tensile test the clamped test body remains in a climatic chamber temperature-controlled at 80° C. for a period of 10 minutes, and

d) during the implementation of the tensile test recording of the tensile forces which occur is effected in dependence on the test time from the beginning of the testing procedure in a range of nominal stretch εt (in accordance with ISO 527-1:1996 Section 10.2) of between 0% and 100%.

2. A composite film according to claim 1 which is a furniture film.

3. A composite film according to claim 1 characterised in that the ABS is an ABS with admixtures.

4. A composite film according to claim 1 characterised in that the polystyrene is a polystyrene with admixtures or a high impact polystyrene.

5. A composite film according to claim 1 characterised in that the polyester is an amorphous polyester copolymer.

6. A composite film according to claim 1 characterised in that the carrier layer of the composite film is of a thickness of between 100 and 1000 μm.

7. A composite film according to claim 1 characterised in that it has at least one carrier layer with amorphous polyester copolymer, wherein in the single-axis tensile testing of such a composite film a maximum tensile force of between 50 Newtons and 120 Newtons, or between 65 Newtons and 105 Newtons, occurs.

8. A composite film according to claim 7 characterised in that it is of a thickness of between 200 and 600 μm, or between 300 and 450 μm.

9. A composite film according to claim 1 characterised in that it has at least one carrier layer with ABS or polystyrene wherein in the single-axis tensile testing of such a composite film a maximum tensile force of between 50 Newtons and 230 Newtons, or between 105 Newtons and 235 Newtons, occurs.

10. A composite film according to claim 9 characterised in that in the tensile testing of such a composite film a maximum tensile force of between 105 Newtons and 180 Newtons occurs.

11. A composite film according to claim 9 characterised in that the polystyrene is HIPS.

12. A composite film according to claim 9 characterised in that it is of a thickness of between 400 and 1000 μm, or between 600 and 800 μm.

13. A composite film according to claim 1 characterised in that the composite film under a cover layer has a single-layer extrudate or at least double-layer co-extrudate as the carrier layer.

14. A composite film according to claim 13 characterised in that at least one layer of the composite film has UV-stabilisers or UV-absorbers or pigments in a proportion by volume of between 0.1 and 10%.

15. A composite film according to claim 13 characterised in that the carrier layer or at least one layer of the carrier layer has additives for Vicat reduction with a proportion by weight of between 1 and 70%.

16. A composite film according to claim 13 characterised in that the carrier layer or at least one layer of the carrier layer have polycaprolactone in a proportion by weight of between 0.5 and 15%.

17. A composite film according to claim 13 characterised in that the carrier layer or at least one layer of the carrier layer have amorphous polyester copolymer in a proportion by weight of between 30 and 70%.

18. A composite film according to claim 13 characterised in that the carrier layer, in the case of a multi-layer, in at least one layer has recycled material from the ongoing production process.

19. A composite film according to claim 18 characterised in that the carrier layer has a double-layer structure.

20. A composite film according to claim 13 characterised in that a primer layer is applied to the side of the carrier layer, which is in opposite relationship to the cover layer of the composite film.

21. A composite film according to claim 13 characterised in that in the case of the single-layer structure thereof the carrier layer is of a thickness of between 94 and 98% of the overall thickness of the composite film.

22. A composite film according to claim 13 characterised in that the cover layer of the composite film is co-extruded together with the carrier layer and has PMMA or impact-resistant modified PMMA.

23. A composite film according to claim 13 characterised in that the composite film has an overall thickness of between 500 and 1000 μm, or between 500 and 800 μm.

24. A composite film according to claim 13 characterised in that the cover layer of the composite film is of a layer thickness of between 1 and 5%, or in the range of from 3 to 4%, of the overall thickness of the composite film.

25. A composite film according to claim 13 characterised in that in the case of a double-layer carrier layer the first layer thereof is of a thickness of between 5 and 20%, or between 10 and 15%, of the overall thickness of the composite film and the second layer of the carrier layer is of a thickness of between 74 and 93%, or between 75 and 85%, of the overall thickness of the composite film.

26. A composite film according to claim 13 characterised in that as the cover layer a transparent scratch-resistant coating is laminated on the carrier layer or applied by thermal transfer printing.

27. A composite film according to claim 26 characterised in that the composite film is of an overall thickness of between 200 and 600 μm, or between 300 and 450 μm.

28. A composite film according to claim 26 characterised in that the cover layer of the composite film is of a layer thickness of between 1 and 5%, or between 1 and 3%, of the overall thickness of the composite film.

29. A composite film according to claim 26 characterised in that in the case of a double-layer carrier layer the first layer thereof is of a thickness of between 20 and 40%, or between 25 and 35%, of the overall thickness of the composite film and the second layer of the carrier layer is of a thickness of between 60 and 75%, or between 65 and 70%, of the overall thickness of the composite film.

30. A composite film according to claim 26 characterised in that as the cover layer a transparent scratch-resistant coating is applied to the carrier layer by printing or lacquering.

31. A composite film according to claim 30 characterised in that the composite film is of an overall thickness of between 200 and 600 μm, or between 300 and 450 μm.

32. A composite film according to claim 26 characterised in that the cover layer of the composite film is of a layer thickness of between 1 and 5%, or between 1 and 3%, of the overall thickness of the composite film.

33. A composite film according to claim 30 characterised in that in the case of a double-layer carrier layer the first layer thereof is of a thickness of between 20 and 40%, or between 25 and 35%, of the overall thickness of the composite film and the second layer of the carrier layer is of a thickness of between 60 and 75%, or between 65 and 70%, of the overall thickness of the composite film.

34. A composite film according to claim 13 characterised in that the carrier layer has an additional co-extruded layer facing towards the primer layer.

35. A composite film according to claim 34 characterised in that the additional co-extruded layer comprises amorphous polyester copolymer with anti-blocking additive.

36. A composite film according to claim 13 characterised in that the cover layer is of a multi-layer structure and is laminated as a finished pre-product on to the carrier layer.

37. A composite film according to claim 36 characterised in that the cover layer has four layers, wherein the first layer is a transparent scratch-resistant coating, the second layer is a transparent overlay film comprising amorphous polyester copolymer, the third layer is a decorative layer and the fourth layer is a primer layer.

38. A composite film according to claim 36 characterised in that the composite film is of an overall thickness of between 200 and 600 μm, or between 300 and 450 μm.

39. A composite film according to claim 36 characterised in that the cover layer is of a thickness of between 30 and 40%, or between 33 and 37%, of the overall thickness of the composite film.

40. A composite film according to claim 13 characterised in that the side of the carrier layer, which is in opposite relationship to the cover layer, has at least one decorative layer or at least one colour cover layer or at least one primer layer.

41. A composite film according to claim 40 characterised in that the cover layer has a transparent scratch-resistant coating with UV-stabilisers and/or UV-absorbers.

42. A composite film according to claim 40 characterised in that the co-extruded carrier layer is at least 80% of the overall thickness of the composite film.

43. A composite film according to claim 40 characterised in that the first layer of the carrier layer is chemically and/or mechanically matted.

44. A composite film according to claim 40 characterised in that the decorative or colour cover layer(s) is(are) applied to the carrier layer by copper intaglio printing or flexographic printing or screen printing or offset printing.

45. A composite film according to claim 40 characterised in that the carrier layer is transparent.

46. A multi-layer, substantially vinyl- and polyolefin-free composite film, which has at least one carrier layer comprising ABS or polystyrene or polyester characterised in that the composite film under a cover layer has a single-layer extrudate or at least double-layer co-extrudate as the carrier layer.

47. A composite film according to claim 46 which is a furniture film.

48. A composite film according to claim 46 characterised in that the ABS is an ABS with admixtures.

49. A composite film according to claim 46 characterised in that the polystyrene is a polystyrene with admixtures or a high impact polystyrene.

50. A composite film according to claim 46 characterised in that the polyester is an amorphous polyester copolymer.

51. A composite film according to claim 46 characterised in that as the cover layer a transparent scratch-resistant coating is laminated on the carrier layer or applied by thermal transfer printing.

52. A composite film according to claim 46 characterised in that as the cover layer a transparent scratch-resistant coating is applied to the carrier layer by printing or lacquering.

53. A composite film according to claim 46 characterised in that the carrier layer has an additional co-extruded layer facing towards the primer layer, or comprising amorphous polyester copolymer with anti-blocking additive.

54. A composite film according to claim 53 characterised in that the additional co-extruded layer comprises amorphous polyester copolymer with anti-blocking additive.

55. A composite film according to claim 46 characterised in that the cover layer is of a multi-layer structure and is laminated as a finished pre-product on to the carrier.

56. A composite film according to claim 46 characterised in that the side of the carrier layer, which is in opposite relationship to the cover layer, has at least one decorative layer or at least one colour cover layer or at least one primer layer.

57. A composite film according to claim 56 characterised in that the cover layer has a transparent scratch-resistant coating with US-stabilisers or UV-absorbers.