Highly weatherable acrylic multilayer foil with improved mechanical properties

Abstract

To provide an acrylic foil which can be easily applied or laminated on a substrate and has high weathering resistance and excellent mechanical properties.SOLUTION: The multilayer foil of the invention comprises at least one layer with a homogeneous distribution of silica particles in an acrylic polymer matrix and at least one further layer.EFFECT: The multilayer foil of the invention is very suitable for surface protection of materials such as polyvinyl chloride (PVC) and for use in high pressure laminates (HPL).SELECTED DRAWING: None

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to an acrylic multilayer foil comprising at least one layer in which particulate silica is uniformly distributed in an acrylic polymer matrix and at least one further layer. This multilayer foil has particularly high weather resistance and excellent mechanical properties. The foil of the present invention is therefore highly suitable for the surface protection of materials such as polyvinyl chloride (PVC) and for use in high-pressure laminates (HPL), in particular continuous pressure laminates (CPL).

[0002] prior art HPL is used in a wide range of applications, such as tabletops, doors, furniture, kitchen worktops, and as cladding for building walls, balconies or facades. For example, EP-A-3094493 and EP-A-0166153 describe HPL for indoor and outdoor use.

[0003] For indoor applications, UV protection is usually not required, but HPL for outdoor applications necessarily must have a UV-protective top layer, since the melamine resin in HPL deteriorates rapidly even after short-term exposure to solar UV radiation. Recently, acrylic foils containing one of several UV absorbers have become widely used as top layers for this purpose.

[0004] Although acrylic foils have excellent inherent resistance to solar UV rays, they only have moderate resistance to mechanical damage and can be easily scratched. On the other hand, untreated acrylic materials such as polymethyl methacrylate (PMMA) have poor adhesion to common scratch-resistant coatings, and scratch-resistant HPL with UV protection is not commercially available. Therefore, HPL used for cladding building walls, balconies, and facades only has moderate scratch resistance, and their vulnerability to vandalism has been a long-standing issue, especially in socially problematic urban areas. Furthermore, building walls, balconies, and facades are often exposed to corrosive substances such as bird droppings and urine. Therefore, they must have adequate chemical resistance.

[0005] Furthermore, purely physical adhesion of acrylic foil to HPL reactive resin-coated paper is not sufficient to ensure its stability over many years, and weathering can even cause partial or complete peeling of the acrylic foil from the HPL surface. To overcome this drawback, EP 1664191 proposes laminating the acrylic foil to the melamine resin-impregnated paper on HPL using an adhesion promoter, such as a copolymer containing carboxylic anhydride units. During the HPL preparation procedure, the carboxylic anhydride units chemically react with the melamine resin. The combination of physical and chemical bonding of the acrylic foil to the HPL reactive resin-coated paper, along with the use of UV protection, allows for the preparation of decorative HPL that is stable for years of outdoor use.

[0006] WO 2015 / 180995 discloses a three-layer foil with particularly strong adhesion to HPL substrates and excellent optical properties, in which the outermost layer is a layer comprising a fluoropolymer, the middle layer is a PMMA layer comprising at least one UV absorber and / or UV stabilizer, and the innermost layer is a PMMA layer comprising at least one adhesion promoter that improves adhesion to the substrate.

[0007] However, the long-term weathering stability of the copolymers described in WO 2015 / 180995 is often lower than that of pure PMMA. As a result, even if such copolymers are located under a UV-absorbing PMMA layer, delamination of HPL coated with such materials can occur after prolonged exposure to UV radiation. The moderate weathering stability of these copolymers becomes even more problematic when they are located on top of a PMMA layer and directly exposed to solar UV radiation. For this reason, these copolymers typically cannot be used to attach scratch-resistant layers to acrylic foils intended for outdoor use.

[0008] Object of the invention The object of the present invention was therefore to provide new acrylic foils for finishing HPL that exhibit good initial and long-term adhesion when laminated to HPL. These HPLs should not show signs of delamination even after long-term outdoor use and should have excellent mechanical properties, in particular high scratch resistance.

[0009] Another goal of the present invention was to provide an acrylic foil that not only has high inherent weather resistance but also ensures adequate protection of articles such as HPL from moisture, wind, solar UV radiation and mechanical damage.

[0010] A further aspect of the present invention was to provide an HPL for outdoor use having the above characteristics.

[0011] Finally, another goal of the present invention was to provide a cost-effective preparative method for the production of HPL with desired properties.

[0012] Summary of the Invention The present invention is based on the surprising discovery that incorporating granular silica substantially uniformly into an impact-modified acrylic layer of a multilayer foil significantly improves the adhesion properties of said layer. This layer can be directly coated with a liquid coating composition, such as a scratch-resistant or anti-graffiti coating. Furthermore, this layer has significantly higher UV resistance than conventional adhesion-promoting layers with anhydride-based copolymers. Therefore, HPL with such foils is highly suitable for outdoor use in urban areas.

[0013] As will be readily understood by those skilled in the art, the term "foil" as used herein refers to a sheet having a thickness of less than 5 mm, more preferably less than 1 mm. While the foils of the present invention can be advantageously used as protective coatings, the term "foil" as used herein should generally be distinguished from the term "film." A film is typically the top layer of a multilayer substrate and cannot be handled separately from the aforementioned substrate. In contrast to a film, the foils of the present invention are not necessarily layers of a multilayer article, i.e., they are not necessarily attached to any substrate, and thus can be handled separately and used for a variety of different purposes.

[0014] The silica particles are substantially uniformly dispersed in the molding composition of Layer A, which results in excellent adhesion-promoting effects. As used herein, the term "uniformly" means that the concentration of silica particles within the layer is substantially constant. This observation is quite surprising, since silica particles are often used to reduce adhesion, i.e., as an anti-blocking agent. For example, U.S. Patent Application Publication No. 2015 / 0044441 describes a multilayer PMMA foil that may contain 0.01 to 0.5 wt. % of an anti-blocking agent, such as SiO2 particles. This document also describes the use of 0.5 to 20 wt. % of a matting agent, such as SiO2 particles, in the PMMA layer.

[0015] The inventors have further found that during the preparation of the foils of the present invention, particularly by the co-extrusion method, silica particles remain visible on the surface of the resulting foil. In a preferred embodiment, the silica particles protrude (project) from the foil surface (see Figure 13). This phenomenon is believed to be responsible for the observed adhesion-enhancing effect. The material of layer A also has excellent heat resistance and can therefore be advantageously processed by thermoplastic methods, such as co-extrusion, to form multilayer foils having layers A, B, and optionally C.

[0016] In its first aspect, the present invention relates to a multilayer foil having at least a layer A and a layer B, wherein layer A comprises, based on the total weight of layer A: 0.0 to 78.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0 wt. % of one or more impact modifiers; 2.0 to 40.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 38.0 wt% of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers A molding composition comprising: The cumulative content of polyalkyl(meth)acrylate and one or more impact modifiers in the molding composition of layer A is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, and particularly preferably at least 85% by weight, based on the weight of layer A.

[0017] Layer B contains, based on the total weight of Layer B: 0.0 to 100.0% by weight of polyalkyl (meth)acrylate; 0.0 to 95.0 wt. % of one or more impact modifiers; 0.0 to 40.0% by weight of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising A molding composition comprising: The cumulative content of polyalkyl(meth)acrylate and one or more impact modifiers in the molding composition of Layer B is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, even more preferably at least 90% by weight, and particularly preferably at least 95% by weight, based on the weight of Layer B. In this application, the cumulative content of polyalkyl(meth)acrylate and one or more impact modifiers will be referred to as the "content of impact-modified polyalkyl(meth)acrylate."

[0018] In a further aspect thereof, the present invention relates to a multilayer foil having at least a layer A and a layer B, wherein layer A comprises, based on the total weight of layer A: 0.0 to 78.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0 wt. % of one or more impact modifiers; 2.0 to 40.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 38.0 wt% of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers A molding composition comprising: The content of impact-modifying polyalkyl(meth)acrylate in the molding composition of layer A is at least 50% by weight, based on the weight of layer A, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, and particularly preferably at least 85% by weight.

[0019] Layer B contains, based on the total weight of Layer B: 40.0 to 100.0% by weight of a fluoropolymer; 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; Glass beads 0.0 to 30.0% by weight The molding composition comprises:

[0020] The materials used in this invention have excellent thermal stability, making them well suited for thermoplastic processing such as extrusion, injection molding, and foil forming methods such as the chill roll method. Multilayer foils having layers A, B, and optionally C are usually produced by coextrusion.

[0021] The multilayer foil of the present invention is superior to commercially available foils in terms of weather resistance and mechanical resistance and has improved stability over long periods, typically more than 10 years. As used herein, the term "stability" refers not only to the inherent stability of the foil against weathering and mechanical damage, but also to the durability of its protective effect.

[0022] Furthermore, the multilayer foil of the present invention offers the following advantages: The multilayer foil can be applied to various substrates at various temperatures and using various lamination techniques. When the layer containing granular silica is applied to the substrate, it provides excellent long-term adhesion between the foil and the substrate. In particular, the foil has excellent adhesion to melamine and phenolic resin-based substrates, such as HPL. The layer containing granular silica can be coated directly and uniformly with a liquid coating composition, thereby providing excellent adhesion between the coating layer and the multilayer foil, which makes it possible to impart desired foil properties, such as improved scratch resistance, in a particularly cost-effective manner. - The foil with layers A, B and optionally C can be produced in a cost-effective manner in an extrusion plant. Layer D can then be applied uniformly as a liquid coating onto layer A, if desired. The foil has excellent weather resistance and is also resistant to chemicals. When fluoropolymers are used as the top layer, the foil is practically impermeable to water vapor, has stain-resistant properties, very good chemical resistance to, for example, commercial cleaning compositions and alcoholic beverages, and can be easily cleaned.

[0023] In a further aspect thereof, the present invention relates to a method for producing a foil having a layer A consisting of a moulding composition A, which foil is produced in a foil moulding process, preferably a chill roll process, by 0.0 to 78.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0 wt. % of one or more impact modifiers; 2.0 to 40.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 38.0 wt% of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers Molded from composition A comprising The content of impact-modifying polyalkyl(meth)acrylate in the molding composition of layer A is at least 50% by weight, based on the weight of layer A, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, and particularly preferably at least 85% by weight.

[0024] Yet another aspect of the invention relates to a multilayer article, preferably HPL, comprising a substrate at least partially covered by a foil as defined above, and comprising, starting from the outer surface, layers in the following order: - layer D forming the outer surface of the multilayer article, - layer A, - Tier B and - Layer C, if present.

[0025] Yet another aspect of the invention relates to a multilayer article, preferably a high-pressure laminate, comprising a substrate at least partially covered by a foil as defined above, and comprising, starting from the outer surface, layers in the following order: - Tier C, if present - Tier B and - Tier A.

[0026] Finally, a further aspect of the present invention relates to a method for producing a multilayer article as defined above, which method comprises the step of coating a substrate with a foil of the present invention by coextrusion, lamination or extrusion lamination, wherein the at least partially crosslinked material of the coating layer D is preferably subjected to further crosslinking. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 shows a multilayer foil of the invention consisting of layers A and B. [Figure 2] FIG. 1 shows a multilayer foil having layers A, B and C. [Figure 3] FIG. 1 shows a multilayer foil comprising layers A and B and coated with layer D. [Figure 4] FIG. 1 shows a multilayer foil comprising layers A, B and C and coated with layer D. [Figure 5] FIG. 1 shows a multilayer foil having layers A, B and C. [Figure 6] FIG. 1 shows a substrate coated with a multilayer foil of the present invention comprising layers A and B and coated with layer D. [Figure 7] FIG. 1 shows a substrate coated with a multilayer foil of the present invention comprising layers A, B and C, coated with layer D. [Figure 8] FIG. 1 shows a substrate coated with a multilayer foil of the present invention having layers A and B. [Figure 9] FIG. 1 shows a substrate coated with a multilayer foil of the present invention comprising layers A, B and C, coated with layer D. [Figure 10] FIG. 1 shows a substrate coated with a multilayer foil of the present invention comprising layers A, B and C, coated with layer D. [Figure 11] FIG. 1 shows a substrate coated with a multilayer foil of the present invention having layers A, B and C. [Figure 12]FIG. 1 shows a substrate coated with a multilayer foil of the present invention having layers A, B and C. [Figure 13] Figure 1 shows a micrograph of a multilayer foil according to the invention obtained with a scanning electron microscope JEOL JSM IT 3000. Magnification: 750x, 10 kV, SED detector. The foil sample was frozen in liquid nitrogen, mechanically fractured and the newly obtained surface was analyzed.

[0028] Detailed Description of the Preferred Embodiments A foil having layers A, B and optionally C can be obtained by a method such as coextrusion, where layer A is formed from a molding composition in which silica particles are substantially uniformly dispersed in an impact-modified polyalkyl(meth)acrylate matrix. Layer D can then be applied onto layer A as a liquid coating.

[0029] The following embodiments of the multilayer foil of the invention have shown particularly advantageous properties.

[0030] Foil embodiment 1 The multilayer foil consists of layers A, B and C (see Figure 2). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0031] Layer B contains, based on the total weight of Layer B: 0.0 to 99.9% by weight, preferably 10.0 to 89.9% by weight, of a polyalkyl(meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0032] Layer C, based on the total weight of Layer C, 40.0 to 100.0% by weight, preferably 70.0 to 100.0% by weight, more preferably 85.0 to 100.0% by weight of a fluoropolymer; Polyalkyl (meth)acrylate 0.0 to 60.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 15.0% by weight The molding composition comprises:

[0033] Foil embodiment 2 The multilayer foil consists of layers A, B and C (see Figure 2). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0034] Layer B contains, based on the total weight of Layer B: 0.0 to 99.8% by weight, preferably 10.0 to 89.8% by weight, of a polyalkyl(meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a benzotriazole-type ultraviolet absorber; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0035] Layer C, based on the total weight of Layer C, 40.0 to 100.0% by weight, preferably 70.0 to 100.0% by weight, more preferably 85.0 to 100.0% by weight of a fluoropolymer; Polyalkyl (meth)acrylate 0.0 to 60.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 15.0% by weight The molding composition comprises:

[0036] Foil embodiment 3 The multilayer foil consists of layers A, B and C (see Figure 2). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0037] Layer B contains, based on the total weight of Layer B: 0.0 to 99.8% by weight, preferably 10.0 to 89.8% by weight, of a polyalkyl(meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.0 to 40.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 20.0% by weight of a fluoropolymer; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a benzotriazole-type ultraviolet absorber; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers; The molding composition comprises:

[0038] Layer C, based on the total weight of Layer C, 40.0 to 100.0% by weight, preferably 70.0 to 100.0% by weight, more preferably 85.0 to 100.0% by weight of a fluoropolymer; Polyalkyl (meth)acrylate 0.0 to 60.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 15.0% by weight The molding composition comprises:

[0039] Foil embodiment 4 The multilayer foil consists of layers A, B and C (see Figure 2). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0040] Layer B contains, based on the total weight of Layer B: 0.0 to 99.8% by weight, preferably 10.0 to 89.8% by weight, of a polyalkyl(meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.0 to 40.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 20.0% by weight of a fluoropolymer; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a benzotriazole-type ultraviolet absorber; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers; The molding composition comprises:

[0041] Layer C, based on the total weight of Layer C, 40.0 to 97.0 wt. % of a fluoropolymer, preferably 85.0 to 97.0 wt. %; 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; Glass beads 3.0 to 30.0% by weight, preferably 3.0 to 15.0% by weight The molding composition comprises:

[0042] Foil embodiment 5 The multilayer foil consists of layers A and B (see Figure 1). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 40.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; The molding composition comprises:

[0043] Layer B contains, based on the total weight of Layer B: 40.0 to 100.0% by weight, preferably 70.0 to 100.0% by weight, more preferably 85.0 to 100.0% by weight of a fluoropolymer; Polyalkyl (meth)acrylate 0.0 to 60.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 15.0% by weight The molding composition comprises:

[0044] Foil embodiment 6 The multilayer foil consists of layers A and B (see Figure 1). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 40.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0045] Layer B contains, based on the total weight of Layer B: 40.0 to 97.0 wt. % of a fluoropolymer, preferably 85.0 to 97.0 wt. %; 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; Glass beads 3.0 to 30.0% by weight, preferably 3.0 to 15.0% by weight The molding composition comprises:

[0046] Foil embodiment 7 The multilayer foil consists of layers A and B (see Figure 1). Layer A contains, based on the total weight of layer A: 0.0 to 76.0% by weight, preferably 0.0 to 62.0% by weight, more preferably 0.0 to 50.0% by weight, even more preferably 0.0 to 40.0% by weight, and particularly preferably 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; 20.0 to 96.0% by weight, preferably 30.0 to 92.0% by weight, more preferably 40.0 to 90.0% by weight, even more preferably 50.0 to 90.0% by weight, and particularly preferably 60.0 to 90.0% by weight of one or more impact modifiers; 2.0 to 20.0% by weight, preferably 4.0 to 25.0% by weight, more preferably 5.0 to 20.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 2.0 to 20.0 wt. %, preferably 4.0 to 25.0 wt. %, more preferably 5.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0047] Layer B contains, based on the total weight of Layer B: 40.0 to 100.0% by weight, preferably 70.0 to 100.0% by weight, more preferably 85.0 to 100.0% by weight of a fluoropolymer; Polyalkyl (meth)acrylate 0.0 to 60.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 15.0% by weight The molding composition comprises:

[0048] Foil embodiment 8 The multilayer foil consists of layers A and B (see Figure 1). Layer A contains, based on the total weight of layer A: 0.0 to 76.0% by weight, preferably 0.0 to 62.0% by weight, more preferably 0.0 to 50.0% by weight, even more preferably 0.0 to 40.0% by weight, and particularly preferably 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; 20.0 to 96.0% by weight, preferably 30.0 to 92.0% by weight, more preferably 40.0 to 90.0% by weight, even more preferably 50.0 to 90.0% by weight, and particularly preferably 60.0 to 90.0% by weight of one or more impact modifiers; 2.0 to 20.0% by weight, preferably 4.0 to 25.0% by weight, more preferably 5.0 to 20.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 2.0 to 20.0 wt. %, preferably 4.0 to 25.0 wt. %, more preferably 5.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0049] Layer B contains, based on the total weight of Layer B: 40.0 to 97.0 wt. % of a fluoropolymer, preferably 85.0 to 97.0 wt. %; 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; Glass beads 3.0 to 30.0% by weight, preferably 3.0 to 15.0% by weight The molding composition comprises:

[0050] Foil embodiment 9 The multilayer foil consists of layers A and B (see Figure 1). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0051] Layer B contains, based on the total weight of Layer B: 0.0 to 99.9% by weight, preferably 10.0 to 89.9% by weight, of a polyalkyl(meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0052] Foil embodiment 10 The multilayer foil consists of layers A and B (see Figure 1). Layer A contains, based on the total weight of layer A: 0.0 to 75.9% by weight, preferably 0.0 to 61.9% by weight, more preferably 0.0 to 49.9% by weight, even more preferably 0.0 to 39.9% by weight, and particularly preferably 0.0 to 29.9% by weight of polyalkyl (meth)acrylate; 20.0 to 96.0% by weight, preferably 30.0 to 92.0% by weight, more preferably 40.0 to 90.0% by weight, even more preferably 50.0 to 90.0% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 20.0% by weight, preferably 4.0 to 25.0% by weight, more preferably 5.0 to 20.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 2.0 to 20.0 wt. %, preferably 4.0 to 25.0 wt. %, more preferably 5.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0053] Layer B contains, based on the total weight of Layer B: 0.0 to 99.9% by weight, preferably 10.0 to 89.9% by weight, of a polyalkyl(meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0054] Foil embodiment 11 The multilayer foil consists of layers A and B (see Figure 1). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0055] Layer B contains, based on the total weight of Layer B: 0.0 to 77.9% by weight, preferably 0.0 to 64.8% by weight, more preferably 0.0 to 52.7% by weight, even more preferably 0.0 to 42.7% by weight, and particularly preferably 0.0 to 33.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0% by weight, preferably 30.0 to 95.0% by weight, more preferably 40.0 to 93.0% by weight, even more preferably 50.0 to 93.0% by weight, and particularly preferably 60.0 to 93.0% by weight of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a benzotriazole-type ultraviolet absorber; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 2.0 to 40.0 wt. %, preferably 5.0 to 35.0 wt. %, more preferably 7.0 to 30.0 wt. % of an adhesion-promoting copolymer comprising The molding composition comprises:

[0056] Foil embodiment 12 The multilayer foil consists of layers A and B (see Figure 1). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0057] Layer B contains, based on the total weight of Layer B: 0.0 to 79.9% by weight, preferably 0.0 to 66.8% by weight, more preferably 0.0 to 54.7% by weight, even more preferably 0.0 to 44.7% by weight, and particularly preferably 0.0 to 35.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0% by weight, preferably 30.0 to 95.0% by weight, more preferably 40.0 to 93.0% by weight, even more preferably 50.0 to 93.0% by weight, and particularly preferably 60.0 to 93.0% by weight of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a benzotriazole-type ultraviolet absorber The molding composition comprises:

[0058] Foil embodiment 13 The multilayer foil consists of layers A, B, and C (see Figure 5). Layer A contains, based on the total weight of Layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0059] Layer B contains, based on the total weight of Layer B: 0.0 to 99.8% by weight, preferably 10.0 to 89.8% by weight, of a polyalkyl(meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a benzotriazole-type ultraviolet absorber; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0060] Layer C, based on the total weight of Layer C, 0.0 to 77.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9 wt. % of one or more impact modifiers; 2.0 to 40.0% by weight of granular silica; 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0061] Foil embodiment 14 The multilayer foil consists of layers A, B and C (see Figure 2). Layer A contains, based on the total weight of layer A: 0.0 to 77.9% by weight, preferably 0.0 to 64.9% by weight, more preferably 0.0 to 52.9% by weight, even more preferably 0.0 to 42.9% by weight, and particularly preferably 0.0 to 32.9% by weight of polyalkyl (meth)acrylate; 20.0 to 97.9% by weight, preferably 30.0 to 94.9% by weight, more preferably 40.0 to 92.9% by weight, even more preferably 50.0 to 92.9% by weight, and particularly preferably 60.0 to 92.9% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.1 to 5.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0062] Layer B contains, based on the total weight of Layer B: 0.0 to 99.8% by weight, preferably 10.0 to 89.8% by weight, of a polyalkyl(meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a benzotriazole-type ultraviolet absorber; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0063] Layer C, based on the total weight of Layer C, 0.0 to 77.9% by weight, preferably 0.0 to 64.8% by weight, more preferably 0.0 to 52.7% by weight, even more preferably 0.0 to 42.7% by weight, and particularly preferably 0.0 to 33.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0% by weight, preferably 30.0 to 95.0% by weight, more preferably 40.0 to 93.0% by weight, even more preferably 50.0 to 93.0% by weight, and particularly preferably 60.0 to 93.0% by weight of one or more impact modifiers; 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of a benzotriazole-type ultraviolet absorber; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt % of maleic anhydride; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 2.0 to 40.0 wt. %, preferably 5.0 to 35.0 wt. %, more preferably 7.0 to 30.0 wt. % of an adhesion-promoting copolymer comprising The molding composition comprises:

[0064] Foil embodiment 15 The multilayer foil consists of layers D, A and B (see Figure 3).

[0065] Layer D comprises an at least partially crosslinked polyurethane (meth)acrylate.

[0066] Layers A and B correspond to those of embodiment 11 of the foil.

[0067] Foil embodiment 16 The multilayer foil consists of layers D, A and B (see Figure 3).

[0068] Layer D comprises an at least partially crosslinked polyurethane (meth)acrylate.

[0069] Layers A and B correspond to those of embodiment 12 of the foil.

[0070] Foil embodiment 17 The multilayer foil consists of layers D, A, B and C (see Figure 4).

[0071] Layer D comprises an at least partially crosslinked polyurethane (meth)acrylate.

[0072] Layers A, B and C correspond to those of embodiment 14 of the foil.

[0073] Foil embodiment 18 The multilayer foil consists of layers D, A, B and C (see Figure 4).

[0074] Layer D comprises an at least partially crosslinked polyurethane (meth)acrylate.

[0075] Layers A, B and C correspond to those of embodiment 13 of the foil.

[0076] The compositions of layers A, B, C and D are described in more detail below.

[0077] Layer A The foil of the invention has a layer A consisting of a molding composition comprising silica particles dispersed substantially uniformly in an impact-modified polyalkyl(meth)acrylate matrix. The content of impact-modified polyalkyl(meth)acrylate in layer A is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, and particularly preferably at least 85% by weight, based on the weight of layer A. Typically, the polymer matrix does not contain any fluoropolymer.

[0078] According to the present invention, the presence of one or more impact modifiers in the molding composition of Layer A is essential to ensure good tear resistance and excellent adhesive properties of the foil. Accordingly, Layer A contains 20.0 to 98.0 wt. % of one or more impact modifiers, based on the weight of Layer A. The rubber content of the one or more impact modifiers in the molding composition of Layer A is preferably 6.0 to 35.0 wt. %, preferably 10.0 to 30.0 wt. %, more preferably 12.0 to 25.0 wt. %, even more preferably 15.0 to 20.0 wt. %, and especially preferably 60.0 to 93.0 wt. % of the one or more impact modifiers, based on the weight of Layer A. Therefore, the content of polyalkyl(meth)acrylate in the molding composition of Layer A can be in the range of 0.0 to 78.0 wt %, preferably 0.0 to 65.0 wt %, more preferably 0.0 to 53.0 wt %, even more preferably 0.0 to 43.0 wt %, and particularly preferably 0.0 to 33.0 wt %, based on the weight of Layer A.

[0079] The molding composition of Layer A comprises, based on the total weight of Layer A: 0.0 to 78.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0 wt. % of one or more impact modifiers; 2.0 to 40.0% by weight of granular silica; 0.0 to 38.0 wt% of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; Preferably, 0.0 to 65.0% by weight of polyalkyl (meth)acrylate; 30.0 to 95.0 wt. % of one or more impact modifiers; 5.0 to 30.0% by weight of granular silica; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; More preferably, 0.0 to 53.0% by weight of polyalkyl (meth)acrylate; 40.0 to 93.0 wt. % of one or more impact modifiers; 7.0 to 20.0% by weight of granular silica; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; Even more preferably, 0.0 to 43.0% by weight of polyalkyl (meth)acrylate; 50.0 to 93.0 wt. % of one or more impact modifiers; 7.0 to 20.0% by weight of granular silica; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; Particularly preferably, 0.0 to 33.0% by weight of polyalkyl (meth)acrylate; 60.0 to 93.0 wt. % of one or more impact modifiers; 7.0 to 20.0% by weight of granular silica; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers may include:

[0080] The inventors have further discovered that the adhesion-promoting effect of the particulate silica in Layer A can be further enhanced by using the particulate silica in combination with an adhesion-promoting copolymer. In this embodiment, the molding composition of Layer A comprises, based on the total weight of Layer A: 0.0 to 76.0% by weight of polyalkyl (meth)acrylate; 20.0 to 96.0 wt. % of one or more impact modifiers; 2.0 to 20.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 2.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; Preferably, 0.0 to 62.0% by weight of polyalkyl (meth)acrylate; 30.0 to 92.0 wt. % of one or more impact modifiers; 4.0 to 25.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 4.0 to 25.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; More preferably, 0.0 to 50.0% by weight of polyalkyl (meth)acrylate; 40.0 to 90.0 wt. % of one or more impact modifiers; 5.0 to 20.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 5.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; Even more preferably, 0.0 to 40.0% by weight of polyalkyl (meth)acrylate; 50.0 to 90.0 wt. % of one or more impact modifiers; 5.0 to 20.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 5.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; Particularly preferably, 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; 60.0 to 90.0 wt. % of one or more impact modifiers; 5.0 to 20.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 5.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers may include:

[0081] Furthermore, if Layer A additionally contains a small amount of a fluoropolymer, the chemical resistance and impact resistance of Layer A can be further improved. Thus, in some embodiments, the polymer matrix of Layer A may contain at least one fluoropolymer, such as PVDF, and the fluoropolymer content is typically 0.0 to 38.0 wt %, preferably 0.0 to 28.0 wt %, and more preferably 0.0 to 18.0 wt %, based on the weight of Layer A.

[0082] Layer B The foil of the present invention typically further comprises a layer B directly adjacent to layer A (see Figure 1). The content of impact-modified polyalkyl(meth)acrylate in layer B is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, even more preferably at least 90% by weight, and particularly preferably at least 95% by weight, based on the weight of layer B. Layer B may optionally comprise at least one fluoropolymer such as PVDF, although the composition of layer B is typically different from the composition of layer A. Furthermore, layer B may comprise a small amount of particulate silica, although particulate silica is usually not present in layer B.

[0083] In one embodiment of the present invention, the composition of Layer B is, based on the total weight of Layer B, as follows: 0.0 to 100.0% by weight, preferably 10.0 to 90.0% by weight, of a polyalkyl (meth)acrylate; 0.0 to 95.0% by weight, preferably 10.0 to 90.0% by weight, of one or more impact modifiers; 0.0 to 40.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 20.0% by weight of a fluoropolymer; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight, preferably 0.2 to 4.0% by weight, more preferably 0.3 to 3.0% by weight of one or more ultraviolet stabilizers; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 95.0% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 20.0 wt. %, preferably 0.0 to 10.0 wt. % of an adhesion-promoting copolymer comprising is.

[0084] Preferably, the polyalkyl(meth)acrylate of Layer B is PMMA as described below and the fluoropolymer is PVDF. Furthermore, depending on the substrate to which the foil is applied, Layer B may be substantially free of adhesion-promoting copolymers.

[0085] In yet another embodiment of the present invention, Layer B comprises, based on the total weight of Layer B: 40.0 to 100.0% by weight of a fluoropolymer; 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; Glass beads 0.0 to 30.0% by weight The molding composition comprises:

[0086] The composition of Layer B can be further adjusted to meet the requirements regarding the desired final appearance of the foil.

[0087] If a foil having a matte appearance is desired, Layer B may contain, based on the total weight of Layer B: 40.0 to 97.0 wt. % of a fluoropolymer, preferably 85.0 to 97.0 wt. %; 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; Glass beads 3.0 to 30.0% by weight, preferably 3.0 to 15.0% by weight The molding composition may comprise:

[0088] To obtain a foil with a glossy appearance, Layer B contains, based on the total weight of Layer B: 40.0 to 100.0% by weight, preferably 70.0 to 100.0% by weight, more preferably 85.0 to 100.0% by weight of a fluoropolymer; Polyalkyl (meth)acrylate 0.0 to 60.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 15.0% by weight The molding composition may comprise:

[0089] Furthermore, in both of the above embodiments, it is advantageous in terms of the chemical resistance of the foil that layer B is substantially free of polyalkyl(meth)acrylate.

[0090] This composition of layer B is particularly advantageous when the foil of the invention is used to protect a substrate, so that layer A is directly adjacent to layer B, with layer B based on a fluoropolymer forming the outer surface of said substrate and thereby facing the environment. Layer A is located below layer B, i.e. closer to the surface of the substrate. Layer A therefore functions as an adhesion-promoting layer.

[0091] In this aspect, the glass beads are substantially uniformly dispersed in the polymer matrix of Layer B. In one embodiment, the polymer matrix comprises a combination of a fluoropolymer, e.g., PVDF, and at least one additional polymer, such as a polyalkyl(meth)acrylate, e.g., PMMA. In this embodiment, the fluoropolymer content is typically 40.0 to 100.0 wt. % and the polyalkyl(meth)acrylate content is 0.0 to 30.0 wt. % based on the total weight of Layer B. This corresponds to a fluoropolymer:polyalkyl(meth)acrylate weight ratio of about 1:1 to about 1:0. As one skilled in the art will readily appreciate, the exact composition of the polymer matrix in Layer A can be adjusted depending on the intended use of the foil. Particularly weather-resistant foils can be obtained by using a PMMA / PVDF combination when the weight ratio of PVDF to PMMA is 1.0:0.0 to 1:1 (w / w), more preferably 1.0:0.0 to 1.0:0.40 (w / w), and particularly preferably 1.0:0.0 to 1.0:0.30 (w / w).

[0092] Layer C Adhesion promotion layer C In addition to the above-mentioned layers A and B, the multilayer foil of the present invention may optionally include an adhesion-promoting layer C, such that layer B is located between layers A and C. In this embodiment, layer C acts as an adhesion-promoting layer and thus necessarily includes particulate silica, an adhesion-promoting copolymer, or a combination thereof. Generally, when the multilayer foil has layer C, layer B includes less than 3.0 wt. %, preferably less than 1.0 wt. %, of the adhesion-promoting copolymer, based on the weight of layer B.

[0093] To achieve good adhesion of the foil to a substrate such as HPL, the cumulative content of particulate silica and adhesion-promoting copolymer in layer C is selected to be at least 2.0% by weight, preferably at least 4.0% by weight, more preferably at least 6.0% by weight, and even more preferably at least 8.0% by weight, based on the weight of layer C, and the content of impact-modifying polyalkyl(meth)acrylate in layer C is at least 60% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, and even more preferably at least 80% by weight, based on the weight of layer C.

[0094] Generally, layer C is 0.0 to 78.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0 wt. % of one or more impact modifiers; 0.0 to 40.0% by weight of a fluoropolymer; 0.0 to 40.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 40.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0095] In one embodiment, Layer C comprises particulate silica and does not comprise an adhesion-promoting copolymer. Thus, in this embodiment, the composition of Layer C substantially corresponds to the composition of Layer A. Layer C comprises: 0.0 to 78.0% by weight, preferably 0.0 to 65.0% by weight, more preferably 0.0 to 53.0% by weight, even more preferably 0.0 to 43.0% by weight, and particularly preferably 0.0 to 33.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0% by weight, preferably 30.0 to 95.0% by weight, more preferably 40.0 to 93.0% by weight, even more preferably 50.0 to 93.0% by weight, and particularly preferably 60.0 to 93.0% by weight of one or more impact modifiers; 2.0 to 40.0% by weight, preferably 5.0 to 30.0% by weight, more preferably 7.0 to 20.0% by weight of granular silica; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0096] In yet another embodiment, Layer C comprises an adhesion-promoting copolymer and no particulate silica. Thus, in this embodiment, Layer C comprises: 0.0 to 78.0% by weight, preferably 0.0 to 65.0% by weight, more preferably 0.0 to 53.0% by weight, even more preferably 0.0 to 43.0% by weight, and particularly preferably 0.0 to 33.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0% by weight, preferably 30.0 to 95.0% by weight, more preferably 40.0 to 93.0% by weight, even more preferably 50.0 to 93.0% by weight, and particularly preferably 60.0 to 93.0% by weight of one or more impact modifiers; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 2.0 to 40.0 wt. %, preferably 5.0 to 35.0 wt. %, more preferably 7.0 to 30.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0097] In this embodiment, Layer C includes 2.0 to 40.0 wt %, preferably 5.0 to 35.0 wt %, and more preferably 7.0 to 30.0 wt % of the adhesion-promoting copolymer, based on the weight of Layer C. Thus, the amount of adhesion-promoting monomer in the molding composition of Layer C is typically 0.1 to 10.0 wt %, preferably 0.5 to 8.0 wt %, and more preferably 1.0 to 5.0 wt %, based on the weight of Layer C.

[0098] In yet another embodiment, Layer C comprises an adhesion-promoting copolymer in combination with particulate silica. Thus, in this embodiment, Layer C comprises: 0.0 to 78.0% by weight, preferably 0.0 to 65.0% by weight, more preferably 0.0 to 53.0% by weight, even more preferably 0.0 to 43.0% by weight, and particularly preferably 0.0 to 33.0% by weight of polyalkyl (meth)acrylate; 20.0 to 98.0% by weight, preferably 30.0 to 95.0% by weight, more preferably 40.0 to 93.0% by weight, even more preferably 50.0 to 93.0% by weight, and particularly preferably 60.0 to 93.0% by weight of one or more impact modifiers; 1.0 to 20.0% by weight, preferably 2.0 to 17.0% by weight, more preferably 4.0 to 15.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 1.0 to 20.0 wt. %, preferably 3.0 to 20.0 wt. %, more preferably 7.0 to 15.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers The molding composition comprises:

[0099] In this embodiment, Layer C includes 1.0 to 20.0 wt %, preferably 3.0 to 20.0 wt %, and more preferably 7.0 to 15.0 wt % of the adhesion-promoting copolymer, based on the weight of Layer C. Thus, the amount of adhesion-promoting monomer in the molding composition of Layer C is typically 0.05 to 5.0 wt %, preferably 0.25 to 4.0 wt %, and more preferably 0.5 to 2.5 wt %, based on the weight of Layer C.

[0100] The presence of one or more impact modifiers in the molding composition of Layer C is essential to ensure good tear resistance and excellent adhesion of the foil. Layer C therefore contains 20.0 to 98.0 wt. %, preferably 30.0 to 95.0 wt. %, more preferably 40.0 to 93.0 wt. %, even more preferably 50.0 to 93.0 wt. %, and particularly preferably 60.0 to 93.0 wt. % of one or more impact modifiers, based on the weight of Layer C. Preferably, the rubber content of the one or more impact modifiers in the molding composition of Layer C is 6.0 to 35.0 wt. %, preferably 10.0 to 30.0 wt. %, more preferably 12.0 to 25.0 wt. %, even more preferably 15.0 to 20.0 wt. %, and particularly preferably 60.0 to 93.0 wt. % of the one or more impact modifiers, based on the weight of Layer C.

[0101] Fluoropolymer-based layer C In a further embodiment of the invention, Layer C comprises, based on the total weight of Layer C: 40.0 to 100.0% by weight of a fluoropolymer; 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; Glass beads 0.0 to 30.0% by weight The molding composition may comprise:

[0102] The composition of Layer C can be further tailored to meet the requirements for the desired final appearance of the multilayer foil.

[0103] If a foil having a matte appearance is desired, Layer C may contain, based on the total weight of Layer C: 40.0 to 97.0 wt. % of a fluoropolymer, preferably 85.0 to 97.0 wt. %; 0.0 to 30.0% by weight of polyalkyl (meth)acrylate; Glass beads 3.0 to 30.0% by weight, preferably 3.0 to 15.0% by weight The molding composition may comprise:

[0104] To obtain a foil with a glossy appearance, layer C comprises, based on the total weight of layer C: 40.0 to 100.0% by weight, preferably 70.0 to 100.0% by weight, more preferably 85.0 to 100.0% by weight of a fluoropolymer; Polyalkyl (meth)acrylate 0.0 to 60.0% by weight, preferably 0.0 to 30.0% by weight, more preferably 0.0 to 15.0% by weight The molding composition may comprise:

[0105] Furthermore, in both of the above embodiments, it is advantageous in terms of the chemical resistance of the foil that layer C is substantially free of polyalkyl(meth)acrylate.

[0106] This composition of layer C is particularly advantageous when the foil of the invention is used to protect a substrate, so that layer C, based on a fluoropolymer, forms the outer surface of said substrate and thus faces the environment. Layer A is located below layers C and B, i.e. is in direct contact with the surface of the substrate. In this embodiment, layer A therefore functions as an adhesion-promoting layer.

[0107] Layer D The multilayer foil of the present invention may further comprise a coating layer D adjacent to layer A. Due to the adhesion-promoting effect of the silica particles in layer A, coating layer D can be advantageously uniformly applied as a liquid coating composition and preferably subsequently at least partially cured. Coating layer D may comprise an at least partially crosslinked material selected from crosslinked polyurethanes, crosslinked polyurethane (meth)acrylates, crosslinked poly(meth)acrylates or mixtures thereof.

[0108] Coating layer D can be applied as a coating onto layer A by known methods, for example by roller. Coating layer D is preferably applied so that a closed film of coating composition is formed on layer A, the amount applied being preferably 20 to 150 g / m 2 In particular, the range of 50 to 100 g / m 2 The range is.

[0109] The composition of Layer D will be described in detail below.

[0110] Explanation of each component of layers A to D Silica particles The content of particulate silica dispersed in the polymer matrix of a layer is usually 2.0 to 40.0% by weight, more preferably 5.0 to 30.0% by weight, and particularly preferably 7.0 to 20.0% by weight, based on the total weight of the corresponding layer.

[0111] The presence of granular silica in the multilayer foil of the present invention serves several purposes. The presence of a defined amount of silica particles ensures that layer A of the foil has a rough, hydrophilic surface that can be easily coated with a liquid coating composition. The coating can be applied substantially to the surface of the layer by any method known in the prior art, including dipping, spraying, doctor knife coating, flow coating, and roller or roll application. The coating can be applied to the foil in a particularly easy and cost-effective manner by using roll-to-roll processing. Roll-to-roll manufacturing techniques are well known to those skilled in the art and involve continuous processing of the foil as it is continuously transported between two moving rolls. In a preferred embodiment, the coating of the foil with the intermediate layer is carried out at a temperature ranging from 60°C to 90°C at a speed of 1 m / min to 70 m / min, more preferably 10 m / min to 30 m / min.

[0112] Furthermore, the layer containing particulate silica has surprisingly high adhesion to materials such as melamine-based HPL. The multilayer foil of the present invention can therefore be used directly for laminating various substrates, such as HPL, by applying the layer facing the substrate. Importantly, in this embodiment, the presence of a copolymer containing an acid anhydride copolymer is no longer essential.

[0113] In order to achieve an optimum balance between good handling properties of the multilayer foil and good adhesion properties of the layers, the content of one or several impact modifiers in the layers n im It has been shown to be advantageous to ensure that (wt %) obeys the following relationship: 0.01 * n im ≦n si ≦0.4 * n im n si is the content (wt%) of particulate silica in the layer.

[0114] Granular silica content in the layer n siis 0.01 * n im Below this, the multilayer foil would in principle still serve its desired purpose, but the adhesion of various liquid coatings to the layer and of the layer to some substrates may be somewhat reduced.

[0115] On the other hand, the content of granular silica in the layer, n si is 0.4 * n im If it is higher than this, the brittleness of the layers increases, and as a result the multilayer foil of the invention becomes more difficult to handle.

[0116] Furthermore, in order to achieve an even better balance between the adhesive properties of the layer and its brittleness, the content of one or several impact modifiers in the layer n im It is particularly advantageous if (% by weight) obeys the following relationship: 0.03 * n im ≦n si ≦0.3 * n im where n is the content of one or more impact modifiers in the layer im It is particularly advantageous if (% by weight) obeys the following relationship: 0.05 * n im ≦n si ≦0.2 * n im n si is the content (wt%) of particulate silica in the layer.

[0117] The choice of particulate silica for use in the present invention is not particularly limited, and pyrogenic silica as well as precipitated silica can be used to advantage. Nevertheless, it is preferred that the specific surface area of ​​the silica be less than 200 m2, as measured by the BET method, standard ISO 9277. 2 / g, preferably above 300m 2 / g, more preferably 400m 2 / g, and even more preferably 500m 2It has been shown that the selection of granular silica having a specific surface area of ​​more than 850 m / g is particularly advantageous in terms of adhesion-promoting properties. 2 / g or less.

[0118] Furthermore, it has been found that a high dibutyl phthalate (DBP) absorption of the silica for use in the present invention is beneficial in terms of its adhesion-promoting properties. Silicas for use in the present invention preferably have a DBP absorption of 100 to 500 g / 100 g. More preferred are DBP absorptions in the range of 150 to 450 g / 100 g, and even more preferred are DBP absorptions in the range of 150 to 400 g / 100 g. DBP absorption can be determined according to method ASTM D6854-12a.

[0119] In a preferred embodiment, the silica particles have a weight average particle diameter d in the range of 1.0 μm to 20.0 μm, more preferably 2.0 μm to 15.0 μm. 50 The weight average particle diameter d 50 can be determined by methods known to those skilled in the art, for example by laser diffraction according to standard DIN ISO 13320-1 using commercially available equipment such as a Beckman Coulter Inc. LS 13 320 laser diffraction particle size analyzer.

[0120] Preferably, the silica particles have a 45 μm sieve residue measured according to ISO 3262-19 of 0.1% by weight or less, more preferably 0.01% by weight or less, i.e., a substantial absence of agglomerates with a particle size greater than 45 μm. This allows the silica particles to be dispersed in a particularly homogeneous manner in the matrix of the poly(meth)acrylate foil without the presence of large filler agglomerates, so that the resulting foil exhibits a substantially uniform appearance and has excellent mechanical properties. The presence of a significant amount of larger agglomerates of silica particles in the layer is disadvantageous because such agglomerates tend to cause the foil to crack, thereby reducing the initial tear strength at random locations of the foil.

[0121] Granular silica for use in the present invention typically has an SiO2 content of 95% by weight or more, more preferably 96% by weight or more, and even more preferably 97% by weight or more, based on ISO 3262-19. Furthermore, the use of hydrophilic silica has been shown to be particularly advantageous in terms of adhesion-promoting properties. By "hydrophilic" silica, we mean silica whose surface exhibits hydrophilic behavior when stirred into water, i.e., its surface is completely wetted by water, and thus its contact angle with water at 23±2°C is less than 90°. A simple method for determining whether a silica is "hydrophilic" is to stir it into water. For example, 0.5 g of silica is added to a beaker containing 200 ml of pure water, and the mixture is vigorously stirred (at approximately 100 rpm using a 3 cm diameter impeller) at a temperature of approximately 23±2°C. If the silica is dispersed in water, i.e., does not float on the surface, the silica can be said to be "hydrophilic," which can be assessed with the naked eye.

[0122] Hydrophilic precipitated silica and hydrophilic pyrogenic silica are also known as unmodified silica. Hydrophilic silicas have less than 10%, typically less than 5%, of their surface silanol groups replaced with hydrophobic functional groups such as alkoxy groups. In contrast, hydrophobic silicas are obtained by treating hydrophilic silica with halogenated silanes, alkoxysilanes, or silazanes to render it hydrophobic. Hydrophobic silicas differ from the hydrophilic starting silicas in, among other things, their silanol group density and water vapor adsorption.

[0123] The inventors have found that the silanol group density has a strong influence on the adhesion-promoting properties of granular silica. While not wishing to be bound by theory, the inventors believe that the silanol groups on the surface of the granular silica may chemically interact with the materials of the coating layer D, particularly the isocyanate-type curing agent. Furthermore, when a layer containing granular silica is used as an adhesion-promoting layer, the silanol groups on the surface of the granular silica are expected to interact with various substrate materials. Typically, the silanol group density is 0.5 SiOH / nm 2 or more, more preferably 0.5 to 20.0 SiOH / nm2 , and even more preferably 1.0 to 15.0 SiOH / nm 2 , and even more preferably 1.5 to 10.0 SiOH / nm 2 It is desirable that:

[0124] To determine the silanol group density, the number of silanol groups on the silica surface is first determined using lithium aluminum hydride. However, since hydrophilic precipitated silicas with high surface areas generally have a higher absolute number of silanol groups than hydrophilic precipitated silicas with low surface areas, the silanol group concentration alone is meaningless. As a result, it is necessary to relate the number of silanol groups to the surface area of ​​the silica. The appropriate surface area for this purpose is the BET surface area, because it represents the surface area available to relatively small molecules such as water.

[0125] The silanol group density can be determined according to the following procedure: First, the moisture content is measured by drying a silica sample at 105°C for 2 hours according to ISO 787-2. Then, 2-4 g of sample (accuracy of 1 mg) is transferred to a pressure-resistant glass apparatus (glass flask with a dropping funnel) equipped with a pressure measuring device. In this apparatus, the sample is dried at 120°C for 1 hour under reduced pressure (less than 1 hPa). At room temperature, approximately 40 ml of a 2 wt. % solution of lithium aluminum hydride in diglyme is added dropwise through the dropping funnel. If necessary, further solution is added dropwise until no further pressure increase is observed. The pressure increase resulting from the hydrogen generated when lithium aluminum hydride reacts with the silanol groups of the silica is determined by pressure measurement (using a known volume as a result of the calibration of the apparatus prior to the measurement) with an accuracy of ≤1 hPa. From this pressure increase, the silanol group concentration of the silica, taking into account the moisture content of the silica, can be calculated using the general gas equation. The effect of the solvent vapor pressure must be corrected accordingly. The silanol group density is calculated as follows: Silanol group density = silanol group concentration / BET specific surface area.

[0126] Generally, the tap density of the granular silica employed influences the adhesion-promoting properties of the corresponding layer, so that foils with particularly advantageous adhesion-promoting properties are obtained with granular silica having a tap density, measured in accordance with DIN EN ISO 787-11, of 10 g / l to 800 g / l, more preferably 40 g / l to 500 g / l, even more preferably 80 g / l to 300 g / l.

[0127] It is particularly preferred to use precipitated silica, as described, for example, in Ullmann's Encyclopaedia of Industrial Chemistry, 5th edition, vol. A23, pp. 642-647. The precipitated silica has a specific surface area of ​​850 m2, as measured by the BET method. 2 / g and are obtained by reacting at least one silicate, preferably an alkali metal silicate and / or an alkaline earth metal silicate, with at least one acidifying agent, preferably at least one mineral acid. In contrast to silica gel (see Ullmann's Encyclopaedia of Industrial Chemistry, 5th edition, vol. A23, pp. 629-635), precipitated silica is not composed of a homogeneous three-dimensional SiO2 network, but of individual aggregates and agglomerates. A special feature of precipitated silica is its high proportion of so-called internal surface area, which is reflected in its highly porous structure with micropores and mesopores.

[0128] Precipitated silicas for use in the present invention include, in particular, SIPERNAT® 160, SIPERNAT® 310, SIPERNAT® 320, SIPERNAT® 320DS, SIPERNAT® 325C, SIPERNAT® 350, SIPERNAT® 360, SIPERNAT® 383DS, SIPERNAT® 500LS, SIPERNAT® 570, SIPERNAT® 700, SIPERNAT® 22, SIPERNAT® 570 ... IPERNAT® 22S, SIPERNAT® 50LOS, SIPERNAT® 22, Tixosil® 38, Tixosil® 38A, Tixosil® 38D, Tixosil® 38X, Tixosil® 38AB, Tixosil® 39, Tixosil® 43, Tixosil® 331, Tixosil® 365, Zeoosil® 175BB, Zeosil® Flo-Gard™ 39, Zeosil™ 39AB, Zeosil™ 45, Flo-Gard™ FF320, Flo-Gard™ FF330, Flo-Gard™ FF350, Flo-Gard™ FF370, Flo-Gard™ FF390, Flo-Gard™ SP, Flo-Gard™ SP-D, Hi-Sil™ 213, Hi-Sil™ ABS, Hi-Sil™ HOA, Hi-Sil™ HOA-D, Hi-Sil™ SC50-D, Hi-Sil™ 6 0-M, Hi-Sil™ 72, Hi-Sil™ T-600, Hi-Sil™ T650, Hi-Sil™ 700, Hubersil™ 5170, Hubersorb™ 250, Hubersorb™ 250NF, Hubersorb™ 5121, Hubersorb™ 600, Hubersorb™ E, ZEOFREE™ 110SD, ZEOFREE™ 153, ZEOFREE™ 153B, ZEOFREE™ 182,Examples of such compounds include ZEOFREE (registered trademark) 51, ZEOFREE (registered trademark) 5111, ZEOFREE (registered trademark) 5112, ZEOFREE (registered trademark) 5161, ZEOFREE (registered trademark) 5161A, ZEOFREE (registered trademark) 5161S, ZEOFREE (registered trademark) 5175B, ZEOFREE (registered trademark) 5181, ZEOFREE (registered trademark) 5183, ZEOFREE (registered trademark) 80, and ZEOFREE (registered trademark) 684.

[0129] Unlike pyrogenic silica, precipitated silica can also be used for layers A and C and is known as AEROSIL® (see Ullmann's Encyclopaedia of Industrial Chemistry, 5th edition, vol. A23, pp. 635-642). Pyrogenic silica is obtained by flame hydrolysis from silicon tetrachloride. Due to the completely different preparation method, pyrogenic silica has, among other properties, different surface properties than precipitated silica. This is manifested, for example, by a lower density of silanol groups on the surface. Furthermore, no polyvalent anions are produced in the production of pyrogenic silica.

[0130] Suitable pyrogenic silicas of the AEROSIL® type from Evonik Industries AG are, for example, AEROSIL® 90, AEROSIL® 130, AEROSIL® 150, AEROSIL® 200, AEROSIL® 300, AEROSIL® 380, AEROSIL® Ox50, but also Cab-O-Sil® M5, Cab-O-Sil® EH5, Cab-O-Sil® S17, HDK T40, HDK N20, HDK N20E.

[0131] Polyalkyl(meth)acrylate Polyalkyl(meth)acrylates are usually obtained by free radical polymerization of a mixture containing an alkyl(meth)acrylate, typically methyl methacrylate (a) and at least one additional (meth)acrylate (b). These mixtures generally contain at least 50% by weight, preferably at least 60% by weight, particularly preferably at least 80% by weight, and even more preferably at least 90% by weight of methyl methacrylate (a), based on the weight of the monomers. The amount of methyl methacrylate (a) typically used is 50.0% to 99.9% by weight, preferably 80.0% to 99.0% by weight, particularly preferably 90.0% to 99.0% by weight, based on the weight of the monomers.

[0132] These mixtures for producing polyalkyl(meth)acrylates may contain other (meth)acrylates (b) copolymerizable with methyl methacrylate (a). The term "(meth)acrylate" as used herein is meant to encompass methacrylates, acrylates, and mixtures thereof. The (meth)acrylates may be derived from saturated alcohols, such as methyl acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, or from unsaturated alcohols, such as oleyl (meth)acrylate, 2-propynyl (meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, as well as aryl (meth)acrylates, such as benzyl (meth)acrylate or phenyl (meth)acrylate, cycloalkyl (meth)acrylates, and the like. Acrylates such as 3-vinylcyclohexyl (meth)acrylate, bornyl (meth)acrylate, hydroxyalkyl (meth)acrylates such as 3-hydroxypropyl (meth)acrylate, 3,4-dihydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycol di(meth)acrylates such as 1,4-butanediol (meth)acrylate, (meth)acrylates of ether alcohols such as tetrahydrofurfuryl (meth)acrylate, vinyloxyethoxyethyl (meth)acrylate, amides and nitriles of (meth)acrylic acid, and the like.

[0133] The amount of (meth)acrylic comonomer (b) generally used is 0.1% by weight to 50.0% by weight, preferably 1.0% by weight to 20.0% by weight, particularly preferably 1.0% by weight to 10.0% by weight, based on the weight of the monomer, and the compounds here can be used alone or in the form of a mixture.

[0134] The polymerization reaction is generally initiated by known free radical initiators. Among the preferred initiators, in particular azo initiators well known to those skilled in the art, such as AIBN and 1,1-azobiscyclohexanecarbonitrile, and peroxy compounds, such as methyl ethyl ketone peroxide, acetylacetone peroxide, dilauryl peroxide, tert-butyl 2-ethylperhexanoate, ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, dibenzoyl peroxide, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl carbonate, 2,5-bis( 2-ethylhexanoylperoxy)-2,5-dimethylhexane, tert-butyl 2-ethylperoxyhexanoate, tert-butyl 3,5,5-trimethylperoxyhexanoate, dicumyl peroxide, 1,1-bis(tert-butylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, cumyl hydroperoxide, tert-butyl hydroperoxide, bis(4-tert-butylcyclohexyl)peroxydicarbonate, or mixtures thereof.

[0135] The composition to be polymerized may contain not only the above-mentioned methyl methacrylate (a) and (meth)acrylate (b), but also other unsaturated monomers copolymerizable with methyl methacrylate and the above-mentioned (meth)acrylates. Among these, in particular, 1-alkenes such as 1-hexene, 1-heptene, branched alkenes such as vinylcyclohexane, 3,3-dimethyl-1-propene, 3-methyl-1-diisobutylene, 4-methyl-1-pentene, acrylonitrile, vinyl esters such as vinyl acetate, styrene, substituted styrenes with alkyl substituents in the side chains such as α-methylstyrene and α-ethylstyrene, maleic acid derivatives such as maleic anhydride, methylmaleic anhydride, maleimide, methylmaleimide, and dienes such as divinylbenzene.

[0136] The amount of these comonomers (c) generally used is 0.0% to 10.0% by weight, preferably 0.0% to 5.0% by weight, particularly preferably 0.0% to 2.0% by weight, based on the weight of the monomers, and the compounds here can be used individually or in the form of a mixture.

[0137] More preferably, the polymerizable component is (a) 50.0% by weight to 99.9% by weight of methyl methacrylate; (b) 0.1 wt% to 50.0 wt% of an acrylic acid ester of a C1 to C4 alcohol; (c) 0.0% by weight to 10.0% by weight of a monomer copolymerizable with the monomers (a) and (b); It is a polyalkyl(meth)acrylate that can be obtained by polymerizing a composition having the formula:

[0138] In yet another embodiment, a polyalkyl(meth)acrylate composed of 85.0 to 99.5% by weight of methyl methacrylate and 0.5 to 15.0% by weight of methyl acrylate is preferred, where the amounts are based on 100% by weight of the polymerizable components. Particularly advantageous copolymers can be obtained by copolymerizing 90.0 to 99.5% by weight of methyl methacrylate with 0.5 to 10.0% by weight of methyl acrylate, where the amounts are based on 100% by weight of the polymerizable components. For example, the polyalkyl(meth)acrylate can contain 91.0% by weight of methyl methacrylate and 9.0% by weight of methyl acrylate, 96.0% by weight of methyl methacrylate and 4.0% by weight of methyl acrylate, or 99.0% by weight of methyl methacrylate and 1.0% by weight of methyl acrylate. The Vicat softening point VSP (ISO 306:2013, method B50) of the aforementioned polyalkyl(meth)acrylates is typically at least 90°C, preferably from 95°C to 112°C.

[0139] The weight-average molar mass Mw of the polyalkyl(meth)acrylate is generally in the range of 50,000 g / mol to 300,000 g / mol. Particularly advantageous mechanical properties are obtained from foils containing polyalkyl(meth)acrylates with an average molar mass Mw ranging from 50,000 g / mol to 180,000 g / mol, preferably from 80,000 g / mol to 160,000 g / mol, in each case determined by GPC against PMMA calibration standards and THF as eluent. Furthermore, the polyalkyl(meth)acrylate preferably contains less than 20% by weight, more preferably less than 10% by weight, even more preferably less than 5% by weight, even more preferably less than 3% by weight, and even more preferably less than 1.5% by weight of oligomeric PMMA with a weight-average molar mass of 300 to 1500 g / m, as measured by SEC against PMMA standards.

[0140] In a particularly preferred embodiment, the polyalkyl(meth)acrylate comprises a polymerizable component having, by weight of the polymerizable composition, (a) 80.0% by weight to 99.0% by weight of methyl methacrylate; (b) 1.0 wt% to 20.0 wt% of an acrylic acid ester of a C1 to C4 alcohol; It can be obtained by polymerization of a composition comprising:

[0141] Impact modifier Impact modifiers for use in the present invention are well known and may have different chemical compositions and polymer structures. Impact modifiers may be crosslinked or thermoplastic. Furthermore, impact modifiers may be in granular form, as core-shell particles or as core-shell-shell particles. Typically, granular impact modifiers have an average particle size of 20 nm to 500 nm, preferably 50 nm to 450 nm, more preferably 100 nm to 400 nm, and most preferably 150 nm to 350 nm. The term "granular impact modifier" as used herein generally refers to crosslinked impact modifiers having a core, core-shell, core-shell-shell, or core-shell-shell-shell structure. The average particle size of a granular impact modifier can be determined by methods known to those skilled in the art, for example, by photon correlation spectroscopy according to standard DIN ISO 13321:1996.

[0142] In the simplest case, the particulate impact modifiers are crosslinked particles obtained by emulsion polymerization with an average particle size in the range of 10 to 150 nm, preferably 20 to 100 nm, and particularly preferably 30 to 90 nm. They generally consist of at least 20.0% by weight, preferably 20.0 to 99.0% by weight, and particularly preferably 30.0 to 98.0% by weight, of butyl acrylate, 0.1 to 2.0% by weight, preferably 0.5 to 1.0% by weight, of a crosslinking monomer, such as a polyfunctional (meth)acrylate, for example, allyl methacrylate, and, if necessary, 0.0 to 10.0% by weight, preferably 0.5 to 5.0% by weight, of other monomers, such as C1-C4-alkyl methacrylates, for example, ethyl acrylate or butyl methacrylate, preferably methyl acrylate, or other vinyl-polymerizable monomers, such as styrene.

[0143] More preferred impact modifiers are polymer particles obtained by emulsion polymerization, which may have a core-shell or core-shell-shell structure (see, for example, EP Patent Application Publication Nos. 0113924, 0522351, 0465049, and 0683028). In the present invention, it is typically necessary that the suitable average particle size of these emulsion polymers is in the range of 20 nm to 500 nm, preferably 50 nm to 450 nm, more preferably 150 nm to 400 nm, and most preferably 200 nm to 350 nm.

[0144] A three-layer or three-phase structure having a core and two shells can be prepared as follows: The innermost (hard) shell can be composed of, for example, methyl methacrylate, a small proportion of a comonomer such as ethyl acrylate, and a proportion of a crosslinker such as allyl methacrylate. The middle (soft) shell can be composed of, for example, a copolymer containing butyl acrylate and, optionally, styrene, while the outermost (hard) shell is the same as the matrix polymer, thus providing compatibility and good bonding to the matrix.

[0145] The proportion of polybutyl acrylate in the core or shell of the impact modifier with a two-layer or three-layer core-shell structure is crucial for the impact modifying effect and is preferably in the range of 20.0 to 99.0% by weight, particularly preferably 30.0 to 98.0% by weight, and even more preferably 40.0 to 97.0% by weight, based on the total weight of the impact modifier.

[0146] In addition to particulate impact modifiers containing polybutyl acrylate or polybutadiene copolymers, it is also possible to use impact modifiers containing siloxanes, however the use of such modifiers is less advantageous since their presence in polyalkyl(meth)acrylate foils tends to be detrimental to the printability of the foil.

[0147] Thermoplastic impact modifiers have a different mechanism of action than particulate impact modifiers. They are generally mixed with a matrix material. If domains are formed, as occurs, for example, when using block copolymers, the preferred size of these domains (which can be determined, for example, by electron microscopy) corresponds to the preferred size of the core-shell particles.

[0148] There are various classes of thermoplastic impact modifiers, including aliphatic thermoplastic polyurethanes (TPUs), such as the Desmopan® products available from Covestro AG. For example, the TPUs Desmopan® WDP 85784A, WDP 85092A, WDP 89085A, and WDP 89051D all have refractive indices between 1.490 and 1.500 and are particularly suitable as impact modifiers.

[0149] A further class of thermoplastic polymers for use according to the foil of the invention as impact modifiers are methacrylate-acrylate block copolymers, in particular acrylic TPEs, including PMMA-poly-n-butylacrylate-PMMA triblock copolymers, commercially available from Kuraray under the product name Kurarity®, where the poly-n-butylacrylate blocks form nanodomains of 10 nm to 20 nm in size in the polymer matrix.

[0150] In addition to the thermoplastic impact modifiers mentioned above, thermoplastic impact modifiers, including PVDF, can also be used, however, the use of such modifiers in Layers A and C is less advantageous as they tend to impair the adhesion-promoting properties of the layers.

[0151] Fluoropolymer Depending on the intended use of the foil of the invention, the fluoropolymer may be chosen from polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE), polyethylenetetrafluoroethylene (ETFE), fluorinated ethylene-propylene (FEP) or mixtures thereof.

[0152] The PVDF polymer used for the foil is generally a transparent, semi-crystalline thermoplastic fluoropolymer. Advantageously, PVDF has a high crystalline melting point. If the crystalline melting point of PVDF is at least 150°C, more preferably at least 160°C, the foil will have particularly high heat resistance. The upper limit of the crystalline melting point is preferably about 175°C, which is equal to the crystalline melting point of PVDF. More preferably, the weight-average molar mass Mw of PVDF, as determined by GPC, is in the range of 50,000 to 300,000 g / mol, more preferably 80,000 to 250,000 g / mol, and even more preferably 150,000 to 250,000 g / mol.

[0153] The basic unit of PVDF is vinylidene fluoride, which is obtained by polymerizing it in high-purity water under controlled conditions of pressure and temperature with a specific catalyst. Vinylidene fluoride can be obtained, for example, by using hydrogen fluoride and methyl chloroform as starting materials and chlorodifluoroethane as a precursor. In principle, any commercially available grade of PVDF is suitable for use in the present invention, such as Kynar® grades from Arkema, Dyneon® grades from Dyneon, and Solef® grades from Solvay. For example, the following commercially available products can be used: Kynar (registered trademark) 720 (vinylidene fluoride content: 100% by weight, crystalline melting point: 169°C) and Kynar (registered trademark) 710 (vinylidene fluoride content: 100% by weight, crystalline melting point: 169°C) manufactured by Arkema; ​​T850 (vinylidene fluoride content: 100% by weight, crystalline melting point: 173°C) manufactured by Kureha Corporation; Solef (registered trademark) 1006 (vinylidene fluoride content: 100% by weight, crystalline melting point: 174°C) and Solef (registered trademark) 1008 (vinylidene fluoride content: 100% by weight, crystalline melting point: 174°C) manufactured by Solvay Solexis.

[0154] PVDF has three bonding modes of monomers: head-to-head, tail-to-tail, and head-to-tail. Of these, head-to-head and tail-to-tail bonds are called "hetero bonds." The chemical resistance of Layer A is particularly high when the "proportion of hetero bonds" in PVDF is 10 mol% or less. From the viewpoint of reducing the proportion of hetero bonds, PVDF is preferably a resin produced by suspension polymerization. The proportion of hetero bonds is determined by the ratio of PVDF defined in European Patent Application Publication No. 2756950. 19 The fluoropolymer's viscosity can be determined from the peaks in the F-NMR spectrum. Typically, fluoropolymers are not crosslinked, making them suitable for thermoplastic processing. PVDF may contain a matting agent to the extent that it does not impair the transparency of Layer A. Both organic and inorganic matting agents can be used.

[0155] In one embodiment, the fluoropolymer is a predominantly amorphous or microcrystalline PVDF with a haze value of less than 5. The haze value is measured for this purpose in accordance with ASTM D1003 on a 30 μm thick pure fluoropolymer (PVDF) foil at 23° C. Examples of particularly suitable PVDF types with appropriately low haze values ​​are Solef® 9009 from Solvay, T850 from Kureha and Kynar® 9000HD from Arkema.

[0156] UV absorbers and stabilizers Light stabilizers are well known and are described in detail by way of example in Hans Zweifel, Plastics Additives Handbook, Hanser Verlag, 5th Edition, 2001, p. 141 ff. Light stabilizers are understood to include UV absorbers, UV stabilizers and free radical scavengers.

[0157] UV absorbers can be from the group of, for example, substituted benzophenones, salicylates, cinnamates, oxanilides, benzoxazinones, hydroxyphenylbenzotriazoles, triazines or benzylidene malonates. The best-known representative of UV stabilizers / free radical scavengers is provided by the group of sterically hindered amines (hindered amine light stabilizers, HALS).

[0158] Preferably, the combination of UV absorber and UV stabilizer consists of the following components: - UV absorbers of the benzotriazole type, - triazine-type ultraviolet absorbers, - UV stabilizers (HALS compounds).

[0159] These components can be used in the form of individual substances or in the form of mixtures.

[0160] Benzotriazole-type UV absorbers are known in the prior art and are typically 2-(2'-hydroxyphenyl)benzotriazole. Corresponding compounds include, in particular, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(5'-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)- 5-Chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-methylphenyl)-5-chloro-benzotriazole, 2-(3'-sec-butyl-5'-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-4'-octyloxyphenyl)benzotriazole, 2-(3',5'-di-tert-amyl-2'-hydroxyphenyl)benzotriazole, 2-(3',5'-bis-(α,α-dimethylbenzyl)-2'-hydroxyphenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)-carbonylethyl]-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)carbonylethyl]-2'-hydroxyphenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-methylphenyl)benzotriazole '-Hydroxy-5'-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2'-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-ylphenol]; Transesterification products of 2-[3'-tert-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxyphenyl]-2H-benzotriazole with polyethylene glycol 300; [R-CH2CH2-COO-CH2CH2-, where R=3'-tert-butyl-4'-hydroxy-5'-2 Further examples of UV absorbers of the benzotriazole type that can be used include 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-[2-hydroxy-3'-(α,α-dimethylbenzyl)-5'-(1,1,3,3-tetramethylbutyl)-phenyl]benzotriazole, 2-[2-hydroxy-3'-(1,1,3,3-tetramethylbutyl)-5'-(α,α-dimethylbenzyl)-phenyl]benzotriazole.α-dimethylbenzyl)phenyl]benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-3-sec-butyl-5-tert-butylphenyl)benzotriazole and 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, phenol, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)]. These compounds are commercially available from BASF SE (Ludwigshafen, Germany), for example as Tinuvin® 360 and Tinuvin® 234.

[0161] The benzotriazole-type UV absorber can also be used in combination with other UV absorbers, such as bismalonate-type UV absorbers. An example of such a combination is Eusorb® BLA 4200M (a commercial product containing Tinuvin® 329 and Hostavin® B-CAP) available from Eutec Chemical Co. Ltd.

[0162] The amount of benzotriazole-type UV absorber in layer B is 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, very particularly preferably 0.5 to 3.0% by weight, based on the weight of PMMA-based layer B. It is also possible to use mixtures of different benzotriazole-type UV absorbers.

[0163] The triazine type ultraviolet absorber is typically a 2-(2-hydroxyphenyl)-1,3,5-triazine derivative. The 2-(2-hydroxyphenyl)-1,3,5-triazine preferably used includes, in particular, 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-( 2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropanol) 2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[4-(dodecyloxy / tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,Examples of suitable UV absorbers include 5-triazine, 2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]phenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2,4-bis(4-[2-ethylhexyloxy]-2-hydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine. Triazine-type UV absorbers, such as 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol, can also be used. These compounds are commercially available, for example, from BASF SE (Ludwigshafen, Germany) under the trademarks Tinuvin® 1600, Tinuvin® 1577, or Tinuvin® 1545.

[0164] The amount of triazine-type UV absorber is in the range of 0.1 to 5.0% by weight, preferably 0.2 to 3.0% by weight, very particularly preferably 0.5 to 2.0% by weight, based on the weight of the layer. It is also possible to use mixtures of different triazine-type UV absorbers.

[0165] Sterically hindered amines, or HALS (hindered amine light stabilizers), are known UV stabilizers. They can be used to inhibit aging in coatings and plastics, especially polyolefin plastics (Kunststoffe, 74 (1984) 10, pp. 620-623; Farbe + Lack, Volume 96, 9 / 1990, pp. 689-693). The tetramethylpiperidine group present in HALS compounds is responsible for the stabilizing effect. This class of compounds can have no substituent on the piperidine nitrogen, or alternatively, the piperidine nitrogen can be substituted with an alkyl or acyl group. Sterically hindered amines do not absorb in the ultraviolet range. They can capture the free radicals formed, whereas UV absorbers cannot. Examples of HALS compounds which have a stabilizing effect and which can also be used in the form of mixtures are bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro(4,5)-decane-2,5-dione, bis(2,2,6,6-tetramethyl-4-piperidyl)succinate, poly(N-β-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine succinate) or bis(N-methyl-2,2,6,6-tetramethyl-4-piperidyl)sebacate.

[0166] The amount of HALS compound used in each of layers A, B and C is typically 0.0 to 5.0% by weight, preferably 0.1 to 3.0% by weight, and very particularly preferably 0.2 to 2.0% by weight, based on the weight of layer B. It is also possible to use mixtures of different HALS compounds.

[0167] Other costabilizers that can be used are the HALS compounds mentioned above, disulfites such as sodium disulfite, and sterically hindered phenols and phosphites. Such costabilizers may be present in a concentration of 0.1 to 5.0 wt. %, based on the weight of the layer.

[0168] Sterically hindered phenols are particularly suitable for use in the foils of the present invention. Preferred sterically hindered phenols include, in particular, 6-tert-butyl-3-methylphenyl derivatives, 2,6-di-tert-butyl-p-cresol, 2,6-tert-butyl-4-ethylphenol, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl-m-cresol), 4,4'-thiobis(6-tert-butyl-m-cresol), 4,4'-dihydroxydiphenylcyclohexane, alkylated bisphenols, styrenated phenols, 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propanol, pionate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenyl), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), stearyl-β(3,5-di-4-butyl-4-hydroxyphenyl)propionate, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane.Commercially available sterically hindered phenols include SUMILIZER BHT BP-76, WXR, GA-80, and BP-101 (Sumitomo Chemical Co., Ltd.), IRGANOX® 1076, IRGANOX® 565, IRGANOX® 1035, IRGANOX® 1425WL, IRGANOX® 3114, IRGANOX® 1330, and IRGANOX® 1010 (BASF SE), MARK AO-50, -80, -30, -20, -330, and -60 (ADEKA ARGUS), as well as TOMINOX SS, TT (Yoshitomi Pharmaceutical Co., Ltd.), IONOX WSP (ICI), SANTONOX® (MONSANTO), ANTAGE CRYSTAL (Kawaguchi Chemical Industry Co., Ltd.), NOCLIZER Examples include NS-6 (Ouchi Shinko Chemical Industry Co., Ltd.), TOPANOL (registered trademark) CA (ICI), and CYANOX (registered trademark) 1790 (ACC).

[0169] Typically, Layers A, B, or C comprise, based on the total weight of Layer B: 0.5 to 4.0% by weight of a benzotriazole-type compound as a first ultraviolet absorber; 0.5 to 3.0% by weight of a triazine-type compound as a second ultraviolet absorber; 0.2 to 2.0% by weight of HALS type compound as ultraviolet stabilizer may include:

[0170] In embodiments of the present invention in which the multilayer foil has two or more layers containing polymethyl(meth)acrylate, it has been shown to be advantageous in terms of weather resistance and enhanced UV protection if the layer facing the environment contains at least one triazine-type UV absorber and the layer below it contains at least one benzotriazole-type UV absorber. Furthermore, the inventors have found that the triazine-type UV absorber can be replaced by inorganic UV absorbers such as titanium dioxide, tin dioxide or glass in the form of glass beads or glass powder without affecting the long-term stability of the resulting multilayer foil.

[0171] For example, if the multilayer foil is intended to be used such that layer A faces the substrate, thereby acting as an adhesion-promoting layer, the molding composition of layer A may be in a range of from 100 to 1500 wt %, based on the weight of the molding composition: 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers Including, The molding composition of Layer B comprises, based on the weight of the molding composition: 0.1 to 5.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers Advantageously, it comprises:

[0172] In embodiments in which Layer A is coated with Layer D, the molding composition of Layer A comprises, by weight of the molding composition: 0.1 to 5.0% by weight of a triazine-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers Including, The molding composition of Layer B comprises, based on the weight of the molding composition: 0.1 to 5.0% by weight of a benzotriazole-type ultraviolet absorber; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers Advantageously, it comprises:

[0173] Adhesion promoting copolymer Typically, the adhesion-promoting copolymer comprises, by weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5% by weight of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; Includes:

[0174] The vinyl copolymerizable monomer (iii) can be selected from the group of vinyl aromatic monomers, such as α-halogen styrenes, p-methylstyrene, p-tert-butylstyrene, vinylnaphthalene, as well as preferably α-methylstyrene and styrene, with styrene being particularly preferred.

[0175] As used herein, the term "adhesion-promoting monomer" (ii) refers to a monomer having a polymerizable double bond and a reactive functional group capable of reacting with an amino or methylol group. Therefore, the adhesion-promoting copolymer can be chemically interacted with the melamine resin of HPL by contacting it with a material containing methylol melamine and its derivatives, specifically, a melamine resin or its precursor, and then heating the mixture. The reaction temperature for the reactive functional group varies depending on factors such as the presence or absence of a catalyst and the pH value, but is preferably 50 to 200°C, more preferably 110 to 170°C. Since HPL is generally produced at temperatures between 110 and 170°C, the adhesion-promoting copolymer chemically reacts with the melamine resin of HPL.

[0176] Examples of functional groups reactive to amino or methylol groups include, but are not limited to, hydroxyl, carboxyl, amino, amide, acid anhydride, imide, and epoxy groups, with acid anhydride and carboxyl groups being particularly useful. Thus, adhesion-promoting monomers particularly suitable for use in the present invention include, but are not limited to, unsaturated carboxylic acid anhydrides, unsaturated dicarboxylic acid anhydrides, and unsaturated dicarboxylic acid imides. The use of maleic anhydride, methacrylic anhydride, methacrylic acid, maleic anhydride or itaconic anhydride, N-phenylmaleimide, and N-cyclohexylmaleimide has been shown to provide particularly advantageous adhesion-promoting properties. It is particularly advantageous to use GMA (glycidyl methacrylate), maleic acid derivatives such as maleic acid, maleic anhydride (MA), methylmaleic anhydride, maleimide, methylmaleimide, maleamide (MA), phenylmaleimide and cyclohexylmaleimide, fumaric acid derivatives, methacrylic anhydride, acrylic anhydride. The most promising results have been observed with maleic anhydride and methacrylic anhydride.

[0177] In a preferred embodiment, the adhesion-promoting copolymer comprises, by weight of the copolymer: (i) 50.0 to 95.0% by weight, preferably 60.0 to 90.0% by weight, more preferably 70.0 to 85.0% by weight, and even more preferably 70 to 80% by weight of methyl methacrylate; (ii) 0.2 to 25.0% by weight, preferably 0.5 to 20.0% by weight, more preferably 1.0 to 15.0% by weight, and even more preferably 5.0 to 12.0% by weight of maleic anhydride; (iii) 0.0 to 25.0% by weight, preferably 2.0 to 15.0% by weight, of another vinyl copolymerizable monomer having no functional group other than a vinyl functional group; Includes:

[0178] In a most preferred embodiment, the adhesion-promoting copolymer is a copolymer of MMA, styrene and maleic anhydride.

[0179] Glass beads In some embodiments, glass beads may be used in a fluoropolymer matrix to impart an aesthetically appealing matte appearance to the foil. Depending on the desired gloss level of the foil, the content of glass beads dispersed in the polymer matrix is ​​typically 3.0 to 30.0 wt. %, more preferably 5.0 to 20.0 wt. %, and particularly preferably 10.0 to 15.0 wt. %, based on the total weight of the corresponding layer.

[0180] The glass beads may have an aspect ratio of at least about 4: 1, more preferably at least about 2: 1. Ideally, the glass beads are substantially spherical, i.e., have an aspect ratio of about 1:1.

[0181] The glass beads advantageously have a narrow size distribution. The size distribution can be measured by conventional equipment such as a Malvern particle size analyzer, e.g., Mastersizer 2000. Typically, the glass beads are solid (i.e., non-hollow) glass beads, are not limited to any chemical composition, and can have either a smooth or etched surface. Surface etching can be conveniently carried out by contacting the glass beads with nitric acid for a time sufficient to provide the desired degree of surface etching. To achieve optimal adhesion between the glass beads and the fluoropolymer matrix, the glass beads may have a siloxane layer.

[0182] Depending on the desired optical properties and surface roughness of the foil, the size of the glass beads (average diameter, weight average) is typically selected to be 2.0 μm to 30.0 μm, preferably 5.0 μm to 20.0 μm, and even more preferably 8.0 μm to 15.0 μm. Typically, when glass beads with an average diameter of less than 2.0 μm are used, the surface of the resulting foil no longer appears smooth. On the other hand, when glass beads with an average diameter of more than 30.0 μm are used, the surface roughness becomes relatively large, which is undesirable in many applications.

[0183] Glass bead size - so-called d 50 The particle size (i.e., 50 volume percent of the particles have a particle size less than the specified average particle size) can be measured according to the laser diffraction measurement standard ISO 13320 (2009). Typically, the size of the glass beads is determined by laser light scattering (room temperature 23°C) using a Malvern Mastersizer 2000 from Malvern Instruments equipped with a Minidisperser MS1 at 2000 revolutions per minute (refractive index of dispersion of particles in butyl acetate: 1,462) and evaluated by Fraunhofer diffraction. Another equally suitable instrument for this purpose is the Beckman Coulter LS 13 320 laser diffraction particle size analyzer.

[0184] The inventors have found that both the foils of the invention and substrates laminated with said foils exhibit a particularly uniform matte appearance when at least 20% by weight, more preferably at least 40% by weight, even more preferably at least 60% by weight, and in some cases at least 80% by weight of the glass beads, based on the weight of the glass beads employed, have a diameter higher than the average thickness of the layer in which they are located. Without wishing to be bound by theory, it is believed that in such embodiments the ability of the glass beads to resist external mechanical pressure at the elevated temperatures during the lamination process is particularly high.

[0185] The average thickness of the foil and the average thickness of the individual layers are advantageously determined using micrographs obtained with a scanning electron microscope, such as a JEOL JSM-IT300 (commercially available from JEOL GmbH, Freising, Germany). Sample pieces of a size suitable for measurement can be obtained by freezing the foil in liquid nitrogen and mechanically fracturing it. The newly obtained fracture surface is photographed using a scanning electron microscope.

[0186] To achieve good mechanical properties of the foil, the glass beads are preferably solid, i.e., their refractive index, measured at 20°C for the Na-D line (589 nm), is selected to differ from the refractive index of the polymeric material matrix in layer B based on fluoropolymer by 0.01 to 0.2 units.

[0187] The chemical composition of the glass beads is not particularly limited, and virtually any type of glass available on the market can be used, including fused silica glass, soda-lime silica glass, sodium borosilicate glass, lead oxide glass, aluminosilicate glass, and oxide glass, with soda-lime silica glass being particularly preferred.

[0188] The refractive index of soda lime silica glass is usually 1.51 to 1.52. In a particularly preferred embodiment, the glass beads have the following composition: SiO2 70.0 to 75.0% by weight, Na2O 12.0~15.0% by weight, K2O 0.0~1.5% by weight, CaO 7.0~12.0% by weight, MgO 0.0~5.0% by weight, Al2O30.1~2.5% by weight, Fe2O30.0~0.5wt% It has.

[0189] Examples of suitable glass beads are Spheriglass® products available from Potters Industries LLC, such as Spheriglass® 7025 and Spheriglass® 5000, or Omicron® glass beads Omicron® NP3 and Omicron® NP5 available from Sovitec Mondial SA.

[0190] In some embodiments, the polymer matrix of the fluoropolymer-based layer essentially consists of one or more fluoropolymers, such as PVDF. In these embodiments, the fluoropolymer content is typically 85.0 to 97.0 wt. %, more preferably 88.0 to 95.0 wt. %, and particularly preferably 90.0 to 92.0 wt. %, based on the total weight of the fluoropolymer-based layer. Thus, the fluoropolymer-based layer typically contains 4.0 to 15.0 wt. %, preferably 5.0 to 12.0 wt. %, and particularly preferably 8.0 to 10.0 wt. % of glass beads, based on the total weight of the fluoropolymer-based layer B.

[0191] Coating layer D In one embodiment of the present invention, the foil further comprises a coating layer D adjacent to layer A. Due to the adhesion-promoting effect of the silica particles in layer A, coating layer D can be advantageously uniformly applied as a liquid coating composition and preferably subsequently at least partially cured. Furthermore, coating layer D exhibits excellent adhesion to layer A, characterized by a value of 3 or less, preferably 2 or less, more preferably 1 or less in a crosshatch test.

[0192] Coating layer D may comprise an at least partially crosslinked material selected from crosslinked polyurethanes, crosslinked polyurethane (meth)acrylates, crosslinked poly(meth)acrylates or mixtures thereof.

[0193] Crosslinked polyurethane The use of crosslinked polyurethanes as scratch-resistant coatings is known in the prior art and is described, for example, in US Patent Application Publication No. 2009 / 0085235. These materials are highly suitable for forming highly weather-resistant nano- or microstructured surfaces. Furthermore, Layer D, based on crosslinked polyurethane, exhibits good adhesion to Layer A, as described above.

[0194] Crosslinked polyurethane (meth)acrylate In a further embodiment, coating layer D may comprise an at least partially crosslinked polyurethane (meth)acrylate. Crosslinked polyurethane (meth)acrylates are known in the prior art and are described, for example, in WO 2017 / 109118 and WO 97 / 49746. The coating composition forming layer D comprises a resin component, a hardener component, and optionally further additives such as a radical initiator. The resin component and the hardener component are present in stoichiometric amounts.

[0195] These materials are applied to Layer A in the form of a liquid coating composition and allowed to dry at a well-defined elevated temperature. Under these conditions, the free hydroxyl groups in the resin component react with the isocyanate groups of the hardener component to form a urethane (meth)acrylate prepolymer coating. Importantly, the reactivity of the (meth)acrylic double bonds in the resin component is preserved during this stage. This provides a flexible, tack-free coated multilayer foil that is easy to handle and can be stored in roll form at room temperature for a sufficient period of time. Importantly, undesirable blocking of the roll does not occur, and the coated multilayer foil can be easily unwound for application to a substrate.

[0196] In the second reaction step, typically upon application of the coated foil onto a substrate, a polymerization reaction of the (meth)acrylic double bonds in the resin component of Layer D occurs, which is induced by high temperature and pressure and is accelerated in the presence of a radical initiator.

[0197] Therefore, coatings containing crosslinked polyurethane (meth)acrylates are typically cured in two separate steps. However, in some applications it may be more advantageous to use crosslinked polyurethane (meth)acrylates that can be cured in three or more separate steps.

[0198] Typically, the resin component contains a free reactive (meth)acrylic double bond and at least two reactive hydroxyl groups per molecule. Most preferably, the resin component has the following general formula (I): [ka] (In the formula, R 1 is an alkylene or aliphatic polyether or polyester group, and R 2 and R 3 is an aliphatic group or an alicyclic group, and i=2 to 6, preferably 3 to 5).

[0199] The resin component of general formula (I) preferably has general formula (II): [ka] (wherein i=2 to 6, preferably 3 to 5, and R 1 is formed from a polyfunctional (meth)acrylate monomer having at least one free hydroxyl group according to the alkyl or aliphatic polyether or polyester group, which is reacted with a diisocyanate in a two-fold stoichiometric excess, based on the reactive hydroxyl groups in the (meth)acrylate monomer, to form a urethane group. The free isocyanate group is then reacted with a trihydric, preferably polyfunctional, alcohol to form a second urethane group containing both a free reactive (meth)acrylic double bond and at least two reactive hydroxyl groups per molecule.

[0200] The curing agent component has the general formula (III): R 3 -[N=C=O] j (III) where j is at least 2, preferably 3, and R 3 is an aliphatic or cycloaliphatic residue), which is usually blocked in its reactivity at room temperature.

[0201] The coating composition further comprises a radical former that is stable at room temperature, as well as an inhibitor to prevent premature crosslinking of the (meth)acrylic double bonds. Further optional additives in the composition are typically fillers, color pigments, flame retardants, UV absorbers, and free radical scavengers.

[0202] In the first process step, the coating composition is applied to Layer A of the multilayer foil and partially cured, preferably at a temperature below 100°C. During this stage, the free hydroxyl groups in the resin component react with the isocyanate groups of the curing agent component to form a urethane acrylate prepolymer coating containing reactive (meth)acrylic double bonds. Premature reaction of these (meth)acrylic double bonds can be advantageously prevented by adding an appropriate inhibitor. By carefully controlling the reaction temperature during this process step, the polyaddition reaction occurs only between the free hydroxyl groups of the resin component and the functional groups of the curing agent component, while the reactivity of the (meth)acrylic double bonds of the resin component remains unaffected. This produces a flexible multilayer foil containing a partially coated Layer D. This foil is easy to handle and can be stored for a sufficiently long period of time without undesirable curling.

[0203] In another method step, a multilayer foil containing a urethane acrylate prepolymer coating containing reactive (meth)acrylic double bonds in Layer D is laminated onto a substrate, which may be, for example, wood, plastic, or metal, and a plastic or metal film. Preferably, the substrate is a high-pressure laminate (HPL). The press stack is typically made of multiple substrate materials impregnated with a synthetic resin, which has the partially cured Layer D on at least one multilayer foil as its outermost layer. This press stack is pressed under high pressure and at a temperature above the drying temperature, preferably above 140°C, so that an additional crosslinking reaction of the reactive (meth)acrylic double bonds in Layer D occurs to form a urethane acrylate polymer. Thus, the cured Layer D forms a scratch-resistant polyurethane (meth)acrylate-based coating.

[0204] In a further embodiment, the coating composition may comprise a mixture of components A-C and optionally D, in which case: - component A is a polymerizable (meth)acrylate compound having at least two groups having a (meth)acrylic double bond per molecule and having no hydroxy group, - Component B is a polymerizable (meth)acrylate compound having one or more groups having a (meth)acrylic double bond and at least two hydroxy groups per molecule, component C is a polyurethane prepolymer having at least two hydroxy groups per molecule and no isocyanate groups, - Component D, if present, is a resin having an aminoplast structure with at least two hydroxy groups per molecule.

[0205] Component A typically comprises a compound selected from formula (A1) and (A2), more preferably a mixture of compounds of formula (A1) and (A2). In particular, component A is preferably composed of compounds of formula (A1) and (A2): [ka] (In the formula, R 4 and R 6 are each independently selected from an aliphatic hydrocarbon group, an aliphatic polyether group, and an aliphatic polyester group; R 5 is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, n=2 to 9, preferably 2 to 4, and m=2 to 9, preferably 2 to 4. m acrylic ester groups H2C=CH-C(O)-O- are each a group R 4 is bonded to the group R via an ester group. 6 n acrylate groups are bonded to

[0206] Preferably, R 4 and R 6are independently selected from linear or branched, preferably branched, alkyl groups, particularly preferably alkyl groups having 3 to 10, more preferably 3 to 6, C atoms. 5 is preferably an alkyl group which is open-chain (i.e., linear or branched) or cyclic or which can combine open-chain or branched units, particularly preferably an alkyl group having 3 to 20, more preferably 6 to 12, C atoms. R is preferably in the form of an alkyl group in formula (A1). 4 For example, provides m+1 valencies for bonding to adjacent groups. This applies to other components of the coating system as well.

[0207] [ka] (In the formula, R 7 is an aliphatic hydrocarbon group, and o=2 to 6, preferably 3 to 5. Preferably, R 7 is a linear or branched, preferably branched, alkyl group, particularly preferably an alkyl group having 3 to 10, more preferably 3 to 6 C atoms).

[0208] Component B preferably comprises a compound of formula (B1), particularly preferably consists of a compound of formula (B1): [ka] (In the formula, R 8 is selected from an aliphatic hydrocarbon group, an aliphatic polyether group, or an aliphatic polyester group; R 9 and R 10 are independently an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and p is 2 to 9, preferably 2 to 4. p acrylic ester groups H2C=CH-C(O)-O- are each a group R 8 is bonded to the group R via an ester group. 10 has two hydroxy groups attached to it.

[0209] R 8is preferably a linear or branched, preferably a branched alkyl group, particularly preferably an alkyl group having 3 to 10, more preferably 3 to 6, carbon atoms. 9 is preferably an alkyl group which is open-chain (i.e. linear or branched) or cyclic or which can combine open-chain or branched units, particularly preferably an alkyl group having 3 to 20, more preferably 6 to 12, C atoms. 10 is preferably an alkyl group which is open-chain (i.e. linear or branched) or cyclic or which can combine open-chain or branched units, particularly preferably a linear or branched alkyl group having 3 to 20, more preferably 3 to 10, C atoms.

[0210] Component C is a polyurethane prepolymer having at least two hydroxy groups per molecule and no isocyanate groups, where the hydroxy groups are generally alcoholic hydroxy groups. The polyurethane prepolymer may be linear or branched. It is preferably formed from a polyisocyanate having 2 to 4, preferably 2, isocyanate groups and a polyalcohol having 2 to 4, preferably 2 or 3, alcoholic hydroxy groups. The polyisocyanate and polyhydric alcohol are preferably aliphatic compounds. In the polyurethane prepolymer, the number of subunits formed from polyisocyanate and the number of subunits formed from polyalcohol are preferably 2 to 20, more preferably 2 to 9, respectively. The number of hydroxy groups per molecule of the polyurethane prepolymer is preferably 2 to 9, more preferably 2 to 5.

[0211] Preferred for component C are polyurethane prepolymers that, in addition to at least two hydroxy groups, do not contain any other reactive groups. The term "reactive groups" refers to possible reactions between the components of the coating system; i.e., in these particularly preferred polyurethane prepolymers of component C, the at least two hydroxy groups are the only groups that can react with other components of the coating system to form covalent bonds.

[0212] Component C preferably comprises a polyurethane prepolymer selected from formula (C1) and (C2), i.e., component C comprises a compound of formula (C1) and / or a compound of formula (C2). In particular, component C is preferably composed of a polyurethane prepolymer selected from compounds of formula (C1) and (C2). Also preferred is a combination of compounds (C1) and (C2).

[0213] [ka] (In the formula, R 11 is independently selected at each occurrence from an aliphatic hydrocarbon group optionally substituted with one or more hydroxyl groups, an aliphatic polyether group, and an aliphatic polyester group; R 12 is independently selected at each occurrence from an aliphatic group or an alicyclic hydrocarbon group, and q is 2 to 9.

[0214] All groups R 11 are the same and all groups R 12 are preferably the same.

[0215] Preferably, R 11 is a linear or branched, preferably branched alkyl group, particularly preferably an alkyl group having 3 to 10, more preferably 3 to 6 carbon atoms. 11 R may be substituted with one or more hydroxy groups. Preferably, there are 0, 1 or 2 such hydroxy substituents. 12is preferably an alkyl group which is open-chain (i.e. linear or branched) or cyclic or which can combine open-chain or branched units, particularly preferably an alkyl group having 3 to 20, more preferably 6 to 12 C atoms.

[0216] [ka] (In the formula, R 11 and R 11a is independently selected at each occurrence from an aliphatic hydrocarbon group optionally substituted with one or more OH groups, an aliphatic polyether group, and an aliphatic polyester group; R 12 is independently at each occurrence an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and q is 2 to 9.

[0217] For formula (C2), all groups R 11 and R 11a are the same and all groups R 12 Preferably, R 11 and R 11a are each a linear or branched, preferably branched alkyl group, particularly preferably an alkyl group having 3 to 10, more preferably 3 to 6 carbon atoms. 11 and R 11a may be substituted with one or more hydroxy groups. Preferably, R 11 has one or two hydroxy substituents, and R 11a has 0 or 1 hydroxy substituents. 12 is preferably an alkyl group which is open-chain (i.e. linear or branched) or cyclic or which can combine open-chain or branched units, particularly preferably an alkyl group having 3 to 20, more preferably 6 to 12 C atoms.

[0218] Optional component D is a resin having an aminoplast structure with at least two hydroxy groups per molecule, where the hydroxy groups are generally alcoholic hydroxy groups. The basic structure of the resin of component D can also have a group formed by the reaction of the hydroxy groups, such as an ester group or a urethane group. Preferably, there are 2 to 30, more preferably 10 to 30, hydroxy groups per molecule. The resin having an aminoplast structure is preferably a cured resin in the form of powder. The average molar mass (Mn) of the resin of optional component D is preferably 1,000 g / mol to 1,000,000 g / mol. The resin having an aminoplast structure is preferably a resin having a urea-formaldehyde resin structure obtainable by polymerization (particularly polycondensation) of formaldehyde and urea, and more preferably a powdered cured resin having a urea-formaldehyde resin structure.

[0219] The coating composition for forming layer D is present as a mixture of components A, B, C, and optionally D, optionally in a solvent. Examples of solvents include esters such as ethyl acetate, butyl acetate, 2-butoxyethyl acetate, aliphatic, alicyclic, and aromatic hydrocarbons, alcohols, glycols, glycol ethers, or ketones. The concentration of components A through C, and, if present, D, in the solvent can be, for example, 65% to 95% by weight, based on the total weight of the solution.

[0220] To prepare the resin component of the coating composition, components A to C, and, if present, D, can be provided and mixed. Alternatively, starting products such as mixed-functionality compounds, such as polyols, polyisocyanates, and / or polyacrylates, can be mixed with one or more hydroxyl groups to prepare components A, B, and C during the synthesis of the resin component, particularly for providing components A (e.g., compounds of formula (A1)), B, and C. For example, the resin component can be prepared by a single-stage or multi-stage synthesis at a temperature of 30 to 130°C. Preferably, during the synthesis of the resin component, a resin having an aminoplast structure as component D is present in the synthesis mixture from the start of the synthesis.

[0221] During the preparation of the resin component, the mixture is preferably thermally heated to a temperature of 30 to 130° C. after addition of the resin D having an aminoplast structure.

[0222] In the resin component, component A is preferably present in an amount of 40.0 to 80.0% by weight, component B is present in an amount of 19.0 to 55.0% by weight, component C is present in an amount of 0.5 to 5.0% by weight, and optional component D is present in an amount of 0.5 to 7.0% by weight, where the total weight of components A to C and optionally A to D is 100% by weight. In a more preferred embodiment, the resin component contains 15.0 to 45.0 wt% of the component of formula (A1), 15.0 to 45.0 wt% of the component of formula (A2) (wherein the total amount of (A1) and (A2) is 40.0 to 80.0 wt%), 19.0 to 55.0 wt% of the component of formula (B1), 0.5 to 5.0 wt% of the components (C1) and (C2), and 0.5 to 7.0 wt% of optional component D. Again, the total of the components equals 100 wt%.

[0223] In an even more preferred embodiment, the resin component contains 20.0 to 40.0 wt% of the component of formula (A1), 20.0 to 40.0 wt% of the component of formula (A2) (wherein the total amount of (A1) and (A2) is 40.0 to 80.0 wt%), 25.0 to 47.0 wt% of the component of formula (B1), 0.6 to 3.0 wt% of the components (C1) and (C2), and 1.0 to 5.0 wt% of the component D. Again, the total of the components is 100 wt%.

[0224] In a particularly preferred embodiment, the resin component contains 25.0 to 35.0 wt% of the component of formula (A1), 25.0 to 35.0 wt% of the component of formula (A2) (wherein the total amount of (A1) and (A2) is 50.0 to 70.0 wt%), 30.0 to 42.0 wt% of the component of formula (B1), 0.8 to 2.0 wt% of the components (C1) and (C2), and 2.0 to 4.5 wt% of the component D. Again, the total of the components is 100 wt%.

[0225] Crosslinked poly(meth)acrylate Crosslinked poly(meth)acrylates are also suitable for forming layer D. Corresponding coating compositions are known in the prior art and are described, in particular, in WO 2008 / 155149. Such coating compositions typically contain at least 40% by weight of a (meth)acrylate having at least two double bonds and two different polymerization initiators, preferably at least one photoinitiator and at least one thermal initiator. It is also possible to use two different thermal initiators that act at different temperatures. The (meth)acrylate may preferably be selected from 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and pentaerythrityl tetraacrylate, or a mixture thereof.

[0226] The coating composition may further comprise a lubricant, a colorant, a metallic pigment, a UV stabilizer, a filler, or a nanomaterial.

[0227] Similar to compositions containing polyurethane (meth)acrylates, coatings based on crosslinked poly(meth)acrylates can also be cured in several different process steps. Thus, after the coating is applied to layer A, a pre-cure is carried out. The resulting material is relatively flexible, which is advantageous in terms of handling the multilayer foil. After the coated multilayer foil is applied to the substrate, the final curing of the coating is carried out in a second process step. Due to the high degree of crosslinking, the resulting layer D has high scratch resistance.

[0228] Further Additives The molding composition forming any layer of the present invention may further optionally contain additional additives selected from colorants, dispersants, flow improvers, lubricants, fillers, heat stabilizers, etc. These compounds are well known to those skilled in the art and need not be described in detail here, provided that the properties of the composition are not adversely affected by the following additives.

[0229] Foil characteristics Depending on the envisaged purpose, the foil of the invention may have a total thickness between 1.0 μm and 300.0 μm, more preferably between 1.0 μm and 200.0 μm, even more preferably between 5.0 μm and 100.0 μm.

[0230] The thickness of the foils and their layers according to the present invention can be determined by mechanical scanning according to the standard ISO 4593-1993. Furthermore, the thickness of the foils and their individual layers can be determined using a scanning electron microscope. For this purpose, foil samples can be frozen in liquid nitrogen, mechanically fractured, and the newly obtained surface analyzed.

[0231] The layer A usually has a thickness of 1.0 μm to 30.0 μm, preferably 5.0 μm to 20.0 μm.

[0232] Layer B usually has a thickness of 10.0 μm to 200.0 μm, preferably 15.0 μm to 150.0 μm.

[0233] When present, the adhesion-promoting layer C typically has a thickness of 1.0 μm to 30.0 μm, preferably 2.0 μm to 20.0 μm.

[0234] Due to the presence of protruding silica particles in layer A, the outer surface of layer A of the multilayer foil typically has a roughness value Rz according to DIN 4768 of at least 0.7 μm, preferably 1.0 to 50.0 μm, more preferably 2.0 to 40.0 μm, even more preferably 5.0 to 30.0 μm. Roughness measurements can be carried out using commercially available equipment such as the Form Talysurf 50 from Rank Taylor Hobson GmbH.

[0235] The gloss (R60°) of the outer surface of layer A according to DIN 67530 (01 / 1982) is usually at most 40, preferably at most 30, in particular 15 to 30. The gloss measurement can be carried out using an RL laboratory reflectometer, for example a reflectometer from Fa. Dr. Hach-Lange.

[0236] Foil manufacturing method Depending on the intended application, the foils of the present invention can be produced in any desired thickness. Surprising factors here are their ability to retain a uniform degree of mattness even under mechanical pressure at elevated temperatures, for example during lamination processes, their exceptional weather resistance and mechanical stability, and the extremely high weather resistance and mechanical protection they provide to substrates. However, for the purposes of the present invention, relatively thin plastic moldings, i.e., films or foils, characterized by thicknesses in the range of 10.0 to 200.0 μm, preferably 40.0 to 120.0 μm, and particularly preferably 50.0 to 90.0 μm, are preferred.

[0237] The mixtures of the individual components of layers A, B, and C can be prepared by dry blending the components in powder, granular, or preferably pelletized form. Such mixtures can also be processed to give ready-to-use molding compositions by melting and blending the individual components in the molten state or by melting a dry premix of the individual components. For example, this can be done in a single-screw or twin-screw extruder. The resulting extrudate can then be pelletized. Conventional additives, auxiliaries, and / or fillers can be incorporated directly or added later by the end user, if desired.

[0238] The multilayer foils of the invention can then be produced by methods known per se, for example by coextrusion or lamination, or extrusion lamination.

[0239] One particular manufacturing variant relates to a method comprising a step in which the foil of the invention is formed by a foil forming method, preferably the chill roll method.

[0240] Application of multilayer foils onto substrates The foil according to the invention can be used in a wide range of applications. One of the preferred applications of the foil is the coating of plastic moldings or metal articles. In particular, the substrate to be protected by the foil may be melamine resin-impregnated paper, an optionally fiber-reinforced polymeric material, preferably polyvinyl chloride (PVC), polycarbonate (PC) or polypropylene (PP), or a metal, preferably steel or aluminum, and the coextruded foil is applied directly to the substrate.

[0241] In this case, it is particularly advantageous to coat plastic moldings containing or made of PVC. The protected substrate is advantageously, for example, a window profile made of aluminum, wood, plastic or composite material, to which a decorative foil, preferably made of PC, SAN or PVC, can be attached. This article is then protected from weathering by using the foil according to the invention. Another preferred application of the foil according to the invention is the design of high-specification, durable surface finishes for substrate materials. Furthermore, the foil according to the invention can advantageously be used in traffic control materials (TCM).

[0242] As mentioned above, the foil of the invention can be applied onto a substrate so that layer A is in direct contact with the surface of the substrate, thereby acting as an adhesion-promoting layer. In this embodiment, when the foil of the invention consists essentially of layers A and B, layer B faces the environment and layer A is located between layer B and the substrate. When the foil of the invention further comprises layer C, layer B faces the environment and layer B is located between layer C and layer A. The layers are therefore arranged in the following order: - Tier C (if present) - Layer B - Tier A - Base material.

[0243] Furthermore, if the multilayer foil of the invention comprises a coating layer D, then the coating layer D faces the environment and the layers are in the following order: - Layer D - Tier A - Layer B - Tier C (if present) - Base material.

[0244] A further aspect of the invention is a method for producing a coated article comprising applying a foil onto a surface of a substrate as described above, the coated article comprising a substrate having an outer surface, the substrate being at least partially covered by a foil, the foil having layers arranged in the following order, starting from the outer surface of the coated article: - Tier C (if present) - Layer B - Tier A - Base material Or, alternatively, - Layer D - Tier A - Layer B - Tier C (if present) - Base material.

[0245] The application of the foil according to the invention to a substrate is in any case relatively simple. The foil is preferably applied to the substrate to be protected by co-extrusion. The application of the foil to the material to be protected by foil lamination is also possible. A preferred use is characterized in that the foil is applied to the material to be protected by extrusion lamination. Preferably, extrusion lamination is carried out at a temperature of 120°C or higher and with the application of a mechanical pressure of 1 MPa or higher, preferably 2 MPa or higher, more preferably 4 MPa or higher, more preferably 6 MPa or higher, more preferably 7 MPa or higher.

[0246] In one embodiment of the present invention, the article itself may be a foil or sheet that can be conveniently stored and / or handled in roll form.

[0247] In a preferred embodiment, the coated article of the present invention may be a high-pressure laminate (HPL), a medium-pressure laminate (MPL), or a continuous pressure laminate (CPL). Accordingly, one aspect of the present invention relates to a method for producing a high-pressure laminate using such a foil. In a particularly preferred embodiment, a multilayer material obtainable using the foil of the present invention is a decorative high-pressure laminate (HPL) according to standards EN 438-2 and EN 438-6, which consists of layers of a fibrous material (e.g., paper) web impregnated with a curable resin, which are bonded to each other by the high-pressure process described below. The surface layer of the material, which has a decorative color or pattern on one or both sides, is impregnated with an aminoplastic-based resin, such as a melamine resin. The amino or methylolamino groups present in the decorative layer during the high-pressure process then serve as reaction partners for covalent bonding to a surface-finishing polymethacrylate layer (in this case, the foil). Corresponding high-pressure laminates are described, inter alia, in U.S. Patent Application Publication No. 2017 / 0197391.

[0248] The preparation of the HPL is typically carried out batchwise at a pressure of 1 MPa to 20 MPa, preferably 4 MPa to 15 MPa, more preferably 6 MPa to 10 MPa, and a temperature of 120° C. to 220° C. Under these conditions, the coating layer D, if present, typically undergoes final crosslinking, thereby forming a coating with high scratch resistance.

[0249] The high-pressure method produces a long-lasting bond between the decorative layer and the polymethacrylate layer applied according to the invention. The temperature set during the method and the resulting interpenetration of the melamine resin-saturated decorative paper into the foil ensure sufficient formation of covalent bonds and thus a long-lasting bond to the material.

[0250] The high pressure method is defined as the simultaneous use of heat (temperatures above 120°C) and high pressure (above 3 MPa) so that the curable resin flows and then hardens to produce a relatively high density (at least 1.35 g / cm) with the required surface structure. 3The result is a homogeneous, non-porous material of 1000 MPa (0.25 psi). The high-pressure process can be carried out batchwise or roll-to-roll, i.e., continuously. The latter product is usually called Continuous Pressure Laminate (CPL).

[0251] The method for producing CPL involves providing a curable resin-based support, such as a phenolic resin-based or melamine resin-based support structure. The support structure can include several individual layers, typically paper layers. The paper layer can be utilized as a cardboard layer. One or all of these layers preferably comprise a phenolic resin or a melamine resin. The support structure typically has a thickness of 0.1 mm to 2 mm, more preferably 0.2 mm to 1.5 mm, even more preferably 0.3 mm to 1.2 mm, even more preferably 0.4 mm to 1.0 mm, and even more preferably 0.5 mm to 0.8 mm. The CPL method involves pressing the multilayer foil of the present invention together with the support structure. The time during which the material is exposed to pressure and temperature is typically significantly shorter than in the HPL batch process. In the CPL process, the layers can be pressed into a continuous, endless plate, for example, by using a double-sided heated double-belt press. The double-belt press can include a structured belt (i.e., a belt with a structured / embossed surface). The pressing pressure can be lower than in the production of HPL. Preferably, the pressing is carried out at a pressure of 1.0 MPa to 10 MPa, more preferably 1.5 MPa to 8.0 MPa, even more preferably 2.0 MPa to 6.0 MPa, even more preferably 2.5 MPa to 4.5 MPa, and most preferably 3.0 MPa to 3.5 MPa in the CPL method. The temperature during this step is typically kept in the range of 120°C to 200°C, more preferably 140°C to 180°C, and even more preferably 150°C to 170°C. Under these conditions, coating layer D, if present, typically undergoes final crosslinking, thereby forming a coating with high scratch resistance.

[0252] Table 1 below lists embodiments of the multilayer article of the present invention having particularly advantageous properties. The multilayer article comprises a substrate coated with a multilayer foil according to preferred embodiments 1 to 18 above, and optionally a coating layer D. The embodiments are shown schematically in Figures 6 to 12.

[0253] [Table 1]

[0254] SEM images SEM images were obtained using a JEOL JSM IT300 scanning electron microscope commercially available from JEOL Ltd. Foil samples were frozen in liquid nitrogen, mechanically fractured, and the newly obtained surfaces analyzed.

[0255] The measured parameters were: Variable current of electrons from a tungsten filament (cathode) Vacuum system: rotary pump / oil diffusion pump XYZ rotation and tilt: fully motorized Working distance (WD): 5-70mm (common: 10mm) Sample rotation: 360° Specimen tilt: -5 to 90° (depending on WD) Magnification: 750x Maximum resolution: approx. 3nm Detector: Secondary electron detector (SED) Backscattered electrons (BSE, 5 divisions) Energy Dispersive X-ray Analysis (EDS)

[0256] Sample preparation To measure the foil thickness, the samples were frozen using liquid nitrogen and mechanically fractured. For this purpose, brittle fracture was performed. The fracture surfaces were analyzed.

[0257] Conductive layer All standards were sputtered with gold to provide a conductive surface.

[0258] Image Measurement The average foil thickness and the average thickness of the individual layers were measured on SEM images. All images were stored in an SEM image database along with the relevant measurement parameters to allow for subsequent measurements of existing images.

[0259] The following examples explain the invention in more detail without limiting it.

[0260] Example Multilayer foils were produced by adapter coextrusion using a 35 mm diameter single-screw extruder and a 25 mm diameter single-screw coextruder at 240-250 °C (melt temperature at the extrusion die) and an extrusion speed of 7.3 m / min, using a chill roll method. For three-layer foils, a second 25 mm diameter single-screw coextruder was used. Alternatively, production can be achieved by a multiple manifold coextrusion method, or a combination of adapter and multiple manifold coextrusion.

[0261] The adhesion promoter used was a copolymer of 75% by weight of MMA, 15% by weight of styrene and 10% by weight of maleic anhydride, the weight average molar mass Mw of which was approximately 100,000 g / mol (determined by GPC against PMMA standard).

[0262] Granular silica available from Evonik Industries AG, Hanau, approximately 700 ml 2 A precipitated hydrophilic silica having a specific surface area of ​​0.1g / g (measured by the BET method according to ISO 9277) was used.

[0263] PMMA1 referred to in the following examples is a copolymer of 96% by weight of methyl methacrylate and 4% by weight of methyl acrylate with a weight-average molar mass Mw of 155,000 g / mol (determined by GPC against PMMA standards) and is available from Röhm GmbH, Darmstadt.

[0264] PMMA2 referred to in the following examples is a copolymer of 99% by weight of methyl methacrylate and 1% by weight of methyl acrylate with a weight-average molar mass Mw of 110,000 g / mol (determined by GPC against PMMA standards) and is available from Röhm GmbH, Darmstadt.

[0265] PMMA3 referred to in the following examples is a copolymer of 96% by weight of methyl methacrylate and 4% by weight of methyl acrylate with a weight-average molar mass Mw of 115,000 g / mol (determined by GPC against PMMA standards) and is available from Röhm GmbH, Darmstadt.

[0266] Impact modifiers 1, 3 and 4 referred to in the examples below are acrylic core-shell impact modifiers based on butyl acrylate.

[0267] Impact Modifier 2, referred to in the examples below, is an acrylic core-shell-shell impact modifier based on butyl acrylate.

[0268] Tinuvin® 360 (a benzotriazole-type UV absorber) and Tinuvin® 1600 (a triazine-type UV absorber) are commercially available from BASF SE, Ludwigshafen.

[0269] Chimassorb® 119 is a hindered amine light stabilizer (HALS) commercially available from BASF SE, Ludwigshafen.

[0270] Production Example 1 (according to the present invention) The molding compound for forming Layer A was prepared using a twin-screw extruder. Using a single-screw extruder with a diameter of 35 mm and a single-screw co-extruder with a diameter of 25 mm, the compound was extruded at a melt temperature of 240 to 250°C at an extrusion speed of 7.3 m / min to prepare a three-layer foil with a total thickness of 75 μm.

[0271] The foil had the following composition: Layer A was 10 μm thick and had the following composition: a) 87.0 wt. % of impact modifier 1 b) 10.0 wt. % granular silica c) 2.0 wt. % Tinuvin® 1600 d) 1.0 wt% dispersant.

[0272] Layer B was 60 μm thick and had the following composition: a) 19.7 wt. % of impact modifier 2 b) 55.3 wt% PMMA1 c) 22.2 wt% PMMA3 d) 2.7% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0273] Layer C was 5 μm thick and had the following composition: a) 78.5 wt. % of impact modifier 1 b) 20.0 wt. % adhesion promoter c) 1.3% by weight of Tinuvin® 360 d) 0.2% by weight of Chimassorb® 119.

[0274] Production Example 2 (Comparative Example) A three-layer foil with a total thickness of 75 μm was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: Layer A was 10 μm thick and had the following composition: a) 16.8 wt. % of impact modifier 2 b) 67.6 wt% PMMA2 c) 10.0 wt. % granular silica d) 0.5% by weight of Tinuvin® 360 e) 5.1 wt% ready-to-use mixture of Irganox® 1076 with several dispersants.

[0275] Layer B was 60 μm thick and had the following composition: a) 19.7 wt. % of impact modifier 2 b) 55.3 wt% PMMA1 c) 22.2 wt% PMMA3 d) 2.7% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0276] Layer C was 5 μm thick and had the following composition: a) 78.5 wt. % of impact modifier 1 b) 20.0 wt. % adhesion promoter c) 1.3% by weight of Tinuvin® 360 d) 0.2% by weight of Chimassorb® 119.

[0277] Production Example 3 (according to the present invention) A three-layer foil with a total thickness of 75 μm was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: Layer A was 10 μm thick and had the following composition: a) 65.6 wt. % of impact modifier 1 b) 11.3 wt. % of impact modifier 3 c) 11.3 wt% PMMA d) 10.0 wt. % granular silica e) 1.9% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0278] Layer B was 60 μm thick and had the following composition: a) 19.7 wt. % of impact modifier 2 b) 55.3 wt% PMMA1 c) 22.2 wt% PMMA3 d) 2.7% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0279] Layer C was 5 μm thick and had the following composition: a) 78.5 wt. % of impact modifier 1 b) 20.0 wt. % adhesion promoter c) 1.3% by weight of Tinuvin® 360 d) 0.2% by weight of Chimassorb® 119.

[0280] Production Example 4 (according to the present invention) A three-layer foil with a total thickness of 75 μm was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: Layer A was 10 μm thick and had the following composition: a) 92.5 wt. % of impact modifier 1 b) 7.5 wt.% granular silica.

[0281] Layer B was 60 μm thick and had the following composition: a) 19.7 wt. % of impact modifier 2 b) 55.3 wt% PMMA1 c) 22.2 wt% PMMA3 d) 2.7% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0282] Layer C was 5 μm thick and had the following composition: a) 78.5 wt. % of impact modifier 1 b) 20.0 wt. % adhesion promoter c) 1.3% by weight of Tinuvin® 360 d) 0.2% by weight of Chimassorb® 119.

[0283] Production Example 5 (according to the present invention) A three-layer foil with a total thickness of 75 μm was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: Layer A was 10 μm thick and had the following composition: a) 62.0 wt. % of impact modifier 1 b) 10.6 wt. % impact modifier 3 c) 10.6 wt% PMMA d) 15.0 wt. % granular silica e) 1.8% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0284] Layer B was 60 μm thick and had the following composition: a) 19.7 wt. % of impact modifier 2 b) 55.3 wt% PMMA1 c) 22.2 wt% PMMA3 d) 2.7% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0285] Layer C was 5 μm thick and had the following composition: a) 78.5 wt. % of impact modifier 1 b) 20.0 wt. % adhesion promoter c) 1.3% by weight of Tinuvin® 360 d) 0.2% by weight of Chimassorb® 119.

[0286] Production Example 6 (Comparative Example) A two-layer foil with a total thickness of 45 μm was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: Layer A was 40 μm thick and had the following composition: a) 18.6 wt. % of impact modifier 2 b) 75.1 wt% PMMA2 c) 0.5% by weight of Tinuvin® 360 d) 5.8 wt% ready-to-use mixture of Irganox® 1076 with several dispersants.

[0287] Layer B was 5 μm thick and had the following composition: a) 78.5 wt. % of impact modifier 1 b) 20.0 wt. % adhesion promoter c) 1.3% by weight of Tinuvin® 360 d) 0.2% by weight of Chimassorb® 119.

[0288] Production Example 7 (Comparative Example) A two-layer hydrophilic coating was applied onto layer A of the foil of Preparation Example 6 according to the following procedure: Preparation of the intermediate layer A first copolymer consisting of 88% by weight of methyl methacrylate and 12% by weight of γ-methacryloyloxypropyltrimethoxysilane and a second copolymer consisting of 20% by weight of methyl methacrylate and 80% by weight of butyl methacrylate were dissolved in butyl acetate in a 1:1 ratio and applied as a thin film to the foil. After casting, the coated foil was dried in an oven at 80°C for 20 minutes.

[0289] Preparation of hydrophilic coating A 25% by weight anionic silica sol (30% by weight solids) containing 0.1% by weight of the potassium salt of the 3-sulfopropyl ester of O-ethyldithiocarboxylic acid and 0.4% by weight of an ethoxylated fatty alcohol was applied to the foil with the intermediate layer in a thin film, made up to 100 parts with deionized water. After air drying, the foil with the intermediate layer and hydrophilic coating was dried in a convection oven at 80°C for 20 minutes.

[0290] Production Example 8 (Comparative Example) Layer A of the foil of Preparation Example 6 was subjected to a corona treatment.

[0291] Preparation Example 9 (according to the present invention) A two-layer foil with a total thickness of 75 μm was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: Layer A was 5 μm thick and had the following composition: a) 82.8 wt. % of impact modifier 1 b) 10.0 wt. % adhesion promoter c) 5.0 wt. % granular silica d) 1.8% by weight ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119 e) 0.5 wt.% dispersant.

[0292] Layer B was 70 μm thick and had the following composition: a) 10.3 wt. % of impact modifier 2 b) 89.5 wt% PMMA2 c) 0.2% by weight of Chimassorb® 119.

[0293] Production Example 10 (Comparative Example) A monolayer foil consisting of monolayer A and having a mechanically textured surface (produced with a textured embossing roller) was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 30.0 wt. % of impact modifier 1 b) 10.0 wt. % of impact modifier 2 c) 45.3 wt% PMMA2 d) 12.5 wt% PMMA3 e) 2.2% by weight of a ready-to-use mixture of Tinuvin® 360 and Chimassorb® 119.

[0294] Production Example 11 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 100.0 wt% PMMA1.

[0295] Production Example 12 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 74.8 wt. % of impact modifier 4 b) 10.0 wt. % Degacryl® 6615 (acrylic bead polymer) available from Evonik Industries AG c) 13.3 wt% PMMA d) 1.9% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0296] Production Example 13 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 66.5 wt. % of impact modifier 4 b) 20.0 wt. % Degacryl® 6615 (acrylic bead polymer) available from Evonik Industries AG c) 11.8 wt% PMMA d) 1.7% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0297] Production Example 14 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 78.1 wt. % of impact modifier 4 b) 6.0 wt. % Spheriglass® Potters 5000 CP-01 (glass beads) available from Potters Industries LLC c) 13.9 wt% PMMA d) 2.0 wt. % ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0298] Production Example 15 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 70.6 wt. % of impact modifier 4 b) 15.0 wt. % Spheriglass® Potters 5000 CP-01 (glass beads) available from Potters Industries LLC c) 12.6 wt% PMMA d) 1.8% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0299] Production Example 16 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 70.6 wt. % of impact modifier 4 b) Omicron® NP3 (glass beads) with a 15.0 wt. % P1 coating available from Sovitec Mondial SA c) 12.6 wt% PMMA d) 1.8% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0300] Production Example 17 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 70.6 wt. % of impact modifier 4 b) 15.0 wt. % SIPERNAT® 44MS (zeolite) available from Evonik Industries AG c) 12.6 wt% PMMA d) 1.8% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0301] Production Example 18 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 70.6 wt. % of impact modifier 4 b) 15.0 wt. % granular silica c) 12.6 wt% PMMA d) 1.8% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0302] The composition of the single layer foil therefore corresponds to the composition of layer A of the multilayer foil of the invention.

[0303] Production Example 19 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 70.6 wt. % of impact modifier 4 b) 15.0 wt. % SILBOND® 600 MST (silane-treated quartz filler) available from Quarzwerke GmbH c) 12.6 wt% PMMA d) 1.8% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0304] Production Example 20 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 70.6 wt. % of impact modifier 4 b) 15.0 wt. % SILBOND® 600 VST (silane-treated quartz filler) available from Quarzwerke GmbH c) 12.6 wt% PMMA d) 1.8% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0305] Production Example 21 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 62.3 wt. % of impact modifier 4 b) 25.0 wt. % Spheriglass® Potters 7010 CP-01 (glass beads) available from Potters Industries LLC c) 11.1 wt% PMMA d) 1.6% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0306] Production Example 22 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 62.3 wt. % of impact modifier 4 b) 25.0% by weight of SpheriWhite® 5000 CP-01 (glass beads) available from PQ Corporation c) 11.1 wt% PMMA d) 1.6% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0307] Production Example 23 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 62.3 wt. % of impact modifier 4 b) 25.0% by weight of SpheriWhite® 3000 CP-00 (glass beads) available from PQ Corporation c) 11.1 wt% PMMA d) 1.6% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0308] Production Example 24 (Comparative Example) A monolayer foil consisting of monolayer A was prepared under the same conditions as in Preparation Example 1. This foil had the following composition: a) 62.3 wt. % of impact modifier 4 b) 25.0% by weight of SpheriWhite® 3000 CP-01 (glass beads) available from PQ Corporation c) 11.1 wt% PMMA d) 1.6% by weight of a ready-to-use mixture of Tinuvin® 360, Tinuvin® 1600 and Chimassorb® 119.

[0309] Preparation of Polyurethane-(Meth)acrylate Coating Compositions Preparation of prepolymer solution The preparation was carried out according to the procedure of Austrian Patent No. 404241, Example 1. A glass reactor equipped with a stirring blade was used. The empty reactor was heated to 70°C for 1 hour to dry the internal reactor surface area. During the reaction, dry air was supplied to the reactor below the liquid surface. Then, 591.3 g of dipentaerythritol tetraacrylate, 250.1 g of isophorone diisocyanate, 118.3 g of n-butyl acetate, 0.96 g of dibutyltin dilaurate as a catalyst, and 5.41 g of 4-methoxyphenol as a polymerization inhibitor were added to the reactor.

[0310] The reaction mixture was stirred at 60°C for approximately 4 hours until the content of free isocyanate groups had decreased to half of its initial value (determined according to DIN 53185) due to the formation of urethane bonds. 150.8 g of 2-ethyl-2-(hydroxymethyl)-1,3-propanediol was then added to the reaction mixture, and the reaction was stirred for an additional 3 hours until the isocyanate content had fallen to less than 0.5% due to the formation of additional urethane bonds. The reaction mixture was cooled to room temperature, and 6.97 g of 4-methoxyphenol dissolved in 150.5 g of n-butyl acetate was added.

[0311] Preparation of the coating system 60.00 parts by weight of the above resin component solution was mixed with the following: 20.00 parts by weight of Tolonate™ HDT LV2 (an aliphatic polyisocyanate based on hexamethylene diisocyanate trimer, available from Worlee-Chemie GmbH, Hamburg) as a curing agent component 1.20 parts by weight of tert-butyl perbenzoate as a radical former 0.14 parts by weight of Kosmos® T12N (dibutyltin dilaurate, available from Evonik Industries AG) as catalyst 18.66 parts by weight of n-butyl acetate as diluent.

[0312] Coating of foil with scratch-resistant composition Test series (a) - Application of a 60 μm thick coating layer A polyurethane (meth)acrylate coating system was applied onto layer A of the foils of Preparation Examples 1 and 6. The thickness of coating layer D was approximately 60 μm. The resulting foils were dried at a temperature of 90° C. for 4 minutes, which resulted in a partial curing of the coating.

[0313] Test series (b) - application of a coating layer of 20 to 30 μm thickness Further samples of polyurethane (meth)acrylate coating composition were applied onto layer A of the foils of Preparation Examples 1 to 24 and onto layer B of the foil of Preparation Example 6. The thickness of coating layer D was approximately 20-30 μm. The resulting foils were dried at a temperature below 100° C., which results in a partial cure of the coating.

[0314] Preparation and testing of HPL The foils of Production Examples 1 and 6 of Test Series (a) and the foils of Production Examples 1 to 24 of Test Series (b), coated as described above, were used to prepare HPL. The HPL was prepared by simultaneous lamination of a phenolic resin-impregnated paper layer and a superimposed protective foil according to the conditions described in the specification. Layer C, if present, was in direct contact with the resin-impregnated paper layer and thereby acted as an adhesion-promoting layer. Layer A, coated with a partially cured polyurethane (meth)acrylate coating composition (Layer D), formed the outer surface of the coated HPL. The core of the HPL consisted of phenolic resin-impregnated paper. Between these and the protective foil was melamine resin-impregnated decorative paper. Anthracite-colored HPL was prepared and used for subsequent tests.

[0315] The HPL samples were stored in hot water at 100 °C for 2 hours, or alternatively at 65 °C for 48 hours. Afterwards, the adhesion was tested using the crosshatch test according to standard ISO EN 2409 (2013) with a single cutting hand tool.

[0316] The crosshatch test results were rated as follows: 0 The cut edges are perfectly smooth and not a single grid square is missing. 1 Small pieces of coating are missing at the intersections of the grid lines. The missing area does not exceed 5% of the grid area. 2. The coating is flaking off along the cutting edge and / or grid line intersections. The flaking area is greater than 5% but not more than 15% of the grid area. 3 The coating is partially or completely removed in a wide band along the cutting edge and / or some squares are partially or completely removed. The removed area is more than 15% but not more than 35% of the cross-cut area. 4 Wide bands of coating missing along the cut edges and / or some squares completely or partially missing. The delamination area is greater than 35% but not more than 65% of the cross-cut area. 5 There is some delamination that can no longer be classified as characteristic 4 of lattice cutting.

[0317] The results of test series (a) are summarized in Table 2.

[0318] [Table 2]

[0319] The multilayer foil of Example 1 (according to the invention) showed excellent initial adhesion and long-term resistance in a humid environment, whereas the multilayer foil of Example 6 (comparative example) showed insufficient initial adhesion and was not used for long-term testing.

[0320] The results of test series (b) are summarized in Table 3.

[0321] [Table 3]

[0322] The multilayer foils of Examples 1, 3-5, and 9 (inventive examples) and the single layer foil of Example 18 (comparative example) showed excellent initial adhesion and long-term durability in a humid environment, however, the foil of Example 18 was brittle and difficult to handle.

[0323] The foils of Examples 11 to 13, 15, 16 and 21 to 24 (comparative examples) also had excellent initial adhesive strength, although their long-term durability in a humid environment was insufficient.

[0324] Further testing The HPL obtained with the foil of Preparation Example 1 of test series (b) was subjected to further tests, the results of which are summarized in Table 4.

[0325] [Table 4]

[0326] Thus, the multilayer foil or Example 1 exhibited excellent chemical resistance and long-term resistance in hot and humid environments as well as high tensile strength. [Explanation of symbols]

[0327] 1 layer A 2. Impact-modified polyalkyl(meth)acrylate matrix 3. Silica particles 4 layer B 5 layer C 6 Coating layer D 7 Impact-modified polyalkyl(meth)acrylate matrix 8. Adhesion-promoting layer C having silica particles 9 Base material 10 Silica particles

Claims

1. A multilayer foil having at least a layer A and a layer B, The layer A contains, based on the total weight of the layer A, 0.0 to 78.0% by weight of polyalkyl(meth)acrylate; 20.0 to 98.0 wt. % of one or more impact modifiers; 2.0 to 40.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5 wt % of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 38.0 wt. % of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; A molding composition comprising: the cumulative content of the polyalkyl(meth)acrylate and one or more impact modifiers in the molding composition of layer A is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, and particularly preferably at least 85% by weight, based on the weight of layer A; The layer B contains, based on the total weight of the layer B, 0.0 to 100.0% by weight of polyalkyl(meth)acrylate; 0.0 to 95.0 wt. % of one or more impact modifiers; 0.0 to 40.0 wt. % of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0 wt. % of one or more ultraviolet stabilizers; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5 wt % of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising A molding composition comprising: the cumulative content of polyalkyl (meth)acrylate and one or more impact modifiers in the molding composition of Layer B is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, even more preferably at least 90% by weight, and particularly preferably at least 95% by weight, based on the weight of Layer B; Multi-layer foil.

2. A multilayer foil having at least a layer A and a layer B, The layer A contains, based on the total weight of the layer A, 0.0 to 78.0% by weight of polyalkyl(meth)acrylate; 20.0 to 98.0 wt. % of one or more impact modifiers; 2.0 to 40.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5 wt % of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 20.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 38.0 wt. % of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; A molding composition comprising: the cumulative content of the polyalkyl(meth)acrylate and one or more impact modifiers in the molding composition of layer A is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, and particularly preferably at least 85% by weight, based on the weight of layer A; The layer B contains, based on the total weight of the layer B, 40.0 to 100.0 wt. % of a fluoropolymer; 0.0 to 30.0% by weight of polyalkyl(meth)acrylate; 0.0 to 30.0% by weight of glass beads A molding composition comprising: Multi-layer foil.

3. The content n of one or more impact modifiers in the polyalkyl (meth)acrylate foil, based on the total weight of the layer A ｉｍ (wt %) is related by the following formula: 0.01 ＊ n ｉｍ ≦n ｓｉ ≦0.4 ＊ n ｉｍ [In the formula, n ｓｉ 3. The foil according to claim 1, wherein ρ is the content (in wt. %) of granular silica in the foil.

4. The granular silica has a viscosity of 200 mm as measured by the BET method in accordance with ISO 9277. ２ / g, preferably more than 300m ２ / g, more preferably 400m ２ / g, and even more preferably 500m ２ 4. The foil according to claim 1, having a specific surface area of ​​more than 1 / g.

5. 5. A foil according to any one of claims 1 to 4, wherein the particulate silica is a precipitated silica or a pyrogenic silica, preferably a hydrophilic precipitated silica or a hydrophilic pyrogenic silica.

6. The granular silica has a weight average particle diameter d of 1.0 μm to 20.0 μm, preferably 2.0 μm to 15.0 μm, as measured by a laser diffraction method in accordance with ISO 13320. ５０ 6. A foil according to claim 1, which is a precipitated silica, preferably having

7. The granular silica has a viscosity of 0.5 SiOH / nm ２ or more, more preferably 0.5 to 20.0 SiOH / nm ２ , and even more preferably 1.0 to 15.0 SiOH / nm ２ , and even more preferably 1.5 to 10.0 SiOH / nm ２ 7. The foil according to claim 1, having a silanol group density of 0.1 to 0.

5.

8. 8. The foil of any one of claims 1 to 7, wherein the particulate silica has a DBP absorption, measured according to ASTM D6854-12a, of 100 to 500 g / 100 g, preferably 150 to 450 g / 100 g, even more preferably 150 to 400 g / 100 g.

9. 9. The foil according to claim 1, wherein the granular silica has a tap density, determined according to DIN EN ISO 787-11, of from 10 g / l to 800 g / l, more preferably from 40 g / l to 500 g / l, even more preferably from 80 g / l to 300 g / l.

10. the polyalkyl(meth)acrylate is a polymethyl methacrylate having a weight-average molar mass Mw of 50,000 g / mol to 180,000 g / mol, preferably 80,000 g / mol to 160,000 g / mol, and the polymerizable component comprises, based on the weight of the polymerizable composition: (a) 50.0 to 99.9 wt % of methyl methacrylate; (b) 0.1 to 50.0 wt. % of an acrylic acid ester of a C1 to C4 alcohol; (c) 0.0 to 10.0 wt. % of at least one additional monomer copolymerizable with said monomers (a) and (b); 10. A foil according to claim 1, obtainable by polymerization of a composition comprising:

11. 11. The foil according to claim 1, wherein the one or more impact modifiers are particulate impact modifiers selected from core, core-shell, core-shell-shell and core-shell-shell-shell impact modifiers.

12. The layer B contains, based on the total weight of the layer B, 0.5 to 4.0 wt % of a benzotriazole-type compound as a first ultraviolet absorber; 0.5 to 3.0 wt % of a triazine-type compound as a second ultraviolet absorber; 0.2 to 2.0% by weight of a HALS type compound as an ultraviolet stabilizer 12. The foil according to claim 1, comprising:

13. the foil further comprises a layer C, the layer B being located between the layers A and C; The layer B contains, based on the total weight of the layer B, 0.0 to 100.0% by weight of polyalkyl(meth)acrylate; 0.0 to 95.0 wt. % of one or more impact modifiers; 0.0 to 40.0 wt. % of a fluoropolymer; 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; A molding composition comprising: The layer C is 0.0 to 78.0% by weight of polyalkyl(meth)acrylate; 20.0 to 98.0 wt. % of one or more impact modifiers; 0.0 to 40.0% by weight of granular silica; an adhesion-promoting copolymer, comprising, based on the weight of the adhesion-promoting copolymer: (i) 70.0 to 99.5 wt % of methyl methacrylate; (ii) 0.5 to 15.0 wt. % of an adhesion-promoting monomer; (iii) 0.0 to 25.0% by weight of other vinyl copolymerizable monomers having no functional groups other than vinyl functional groups; 0.0 to 40.0 wt. % of an adhesion-promoting copolymer comprising 0.0 to 5.0% by weight of one or more ultraviolet absorbers; 0.0 to 5.0% by weight of one or more ultraviolet stabilizers; A molding composition comprising: the cumulative content of the polyalkyl(meth)acrylate and one or more impact modifiers in the molding composition of Layer C is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, and even more preferably at least 80% by weight, based on the weight of Layer C; 13. The foil according to any one of claims 1 and 3 to 12, wherein the cumulative content of said particulate silica and said adhesion-promoting copolymer is at least 2.0 wt.-%, preferably at least 4.0 wt.-%, more preferably at least 6.0 wt.-%, even more preferably at least 8.0 wt.-%, based on the weight of said layer C.

14. The foil further comprises a Layer C, the Layer C comprising, based on the total weight of the Layer C: 40.0 to 100.0 wt. % of a fluoropolymer; 0.0 to 30.0% by weight of polyalkyl(meth)acrylate; 0.0 to 30.0% by weight of glass beads 13. The foil according to claim 1, which consists of a molding composition comprising:

15. Layer A has a thickness of 1.0 μm to 30.0 μm, Layer B has a thickness of 15.0 μm to 150.0 μm, The foil of any one of claims 1 and 3 to 14, wherein layer C, if present, has a thickness of from 1.0 μm to 30.0 μm.

16. 16. The foil of any one of claims 1, 3 to 13, and 15, wherein the foil further comprises a coating layer D adjacent to layer A, the coating layer D comprising an at least partially crosslinked material selected from crosslinked polyurethanes, crosslinked polyurethane (meth)acrylates, crosslinked poly(meth)acrylates, or mixtures thereof.

17. A multilayer article, preferably a high-pressure laminate, having an outer surface comprising a substrate at least partially covered by a foil according to any one of claims 1, 3 to 13, 15 and 16, which is subjected to the following steps, starting from the outer surface of the multilayer article: - layer D, if present, forming the outer surface of said multilayer article; - Layer A Layer B; and Layer C, if present 1. A multilayer article, preferably a high pressure laminate, comprising:

18. A multilayer article, preferably a high-pressure laminate, comprising a substrate at least partially covered with a foil according to any one of claims 1 to 16, which is applied, starting from the outer surface, in the following order: - optionally layer C Layer B; and - Layer A 1. A multilayer article, preferably a high pressure laminate, comprising:

19. 19. A method for producing a multilayer article according to claim 17 or 18, comprising the step of coating a substrate with a foil according to any one of claims 1 to 16 by coextrusion, lamination or extrusion lamination, wherein the at least partially crosslinked material of the coating layer D, if present, is preferably subjected to further crosslinking.

20. 20. A method according to claim 19, wherein the multilayer article is a high pressure laminate and the step of coating the substrate with the foil according to any one of claims 1 to 16 is carried out at a pressure of 1 MPa to 20 MPa, preferably 4 MPa to 15 MPa, more preferably 6 MPa to 10 MPa, and at a temperature of 120°C to 220°C.

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