Acrylic foils with improved UV-protection properties

18:

• A multi-layer foil, comprising:
• at least a layer A, and
• a layer B:
• wherein the layer A comprises, based on the total weight of the layer A:
• from 0.0 to 99.9 wt.-% of a polymethyl(meth)acrylate;
• from 0.0 to 95.0 wt.-% of one or several impact modifiers;
• from 0.0 to 30.0 wt.-% of a fluoropolymer;
• from 0.1 to 5.0 wt.-% of a first UV-absorber;
• and
• from 0.0 to 5.0 wt.-% of one or several UV-stabilizers;
• wherein a cumulative content of the polymethyl(meth)acrylate and of one or several impact modifiers in the layer A is at least 50 wt.-% and not more than 99.9 wt.-%, based on the weight of the layer A;
• wherein a spectral transmittance of the layer A at any wavelength λA is not more than 10%;
• wherein 270 nm≤λA≤360 nm;
• wherein the layer B comprises, based on the total weight of the layer B:
• from 0.0 to 99.9 wt.-% of a polymethyl(meth)acrylate;
• from 0.0 to 85.0 wt.-% of one or several impact modifiers;
• from 0.1 to 5.0 wt.-% of a second UV-absorber, which is distinct from the first UV-absorber;
• from 0.0 to 5.0 wt.-% of one or several UV-stabilizers;
• and
• from 0.0 to 20.0 wt.-% of an adhesion-promoting copolymer comprising
• (i) from 70.0 to 95.0 wt.-% methyl methacrylate;
• (ii) from 0.5 to 15.0 wt.-% maleic anhydride;
• and
• (iii) from 0.0 to 25.0 wt.-% of other vinyl-copolymerizable monomers having no functional groups other than the vinyl function, based on the weight of the adhesion-promoting copolymer;
• wherein a cumulative content of the polymethyl(meth)acrylate and of one or several impact modifiers in the layer B is at least 50 wt.-% and not more than 99.9 wt.-%, based on the weight of the layer B,
• wherein a spectral transmittance of the layer B at any wavelength λB is not more than 10%;
• wherein 270 nm≤λB≤370 nm;
• wherein the layer A comprises not more than 0.1 wt.-% of the second UV absorber;
• and
• wherein the layer B comprises not more than 0.1 wt.-% of the first UV absorber.

19:

• A multi-layer foil, comprising:
• at least a layer A, and
• a laver B;
• wherein the layer A comprises, based on the total weight of the layer A:
• from 0.0 to 99.0 wt.-% of a polymethyl(meth)acrylate;
• from 0.0 to 95.0 wt.-% of one or several impact modifiers;
• from 0.0 to 30.0 wt.-% of a fluoropolymer;
• from 1.0 to 30.0 wt.-% of a first UV-absorber,
• wherein the first UV-absorber is an inorganic particulate material;
• and
• from 0.0 to 5.0 wt.-% of one or several UV-stabilizers;
• wherein a cumulative content of the polymethyl(meth)acrylate and of one or several impact modifiers in the layer A is at least 50 wt.-% and not more than 97.0 wt.-%, based on the weight of the layer A;
• wherein a spectral transmittance of the layer A at any wavelength λA is not more than 20%;
• wherein 270 nm≤λA≤310 nm;
• wherein the layer B comprises, based on the total weight of the layer B:
• from 0.0 to 99.9 wt.-% of a polymethyl(meth)acrylate;
• from 0.0 to 85.0 wt.-% of one or several impact modifiers;
• from 0.1 to 5.0 wt.-% of a second UV-absorber, which is distinct from the first UV-absorber;
• from 0.0 to 5.0 wt.-% of one or several UV-stabilizers;
• and
• from 0.0 to 20.0 wt.-% of an adhesion-promoting copolymer comprising
• (i) from 70.0 to 95.0 wt.-% methyl methacrylate;
• (ii) from 0.5 to 15.0 wt.-% maleic anhydride;
• and
• (iii) from 0.0 to 25.0 wt.-% of other vinyl-copolymerizable monomers having no functional groups other than the vinyl function, based on the weight of the adhesion-promoting copolymer;
• wherein a cumulative content of the polymethyl(meth)acrylate and of one or several impact modifiers in the layer B is at least 50 wt.-% and not more than 99.9 wt.-%, based on the weight of the layer B;
• wherein a spectral transmittance of the layer B at any wavelength λB is not more than 10%;
• wherein 270 nm≤λB≤370 nm;
• wherein the layer A comprises not more than 0.1 wt.-% of the second UV absorber;
• and
• wherein the layer B comprises not more than 0.1 wt.-% of the first UV absorber.

20:

• The foil according to claim 18, further comprising an adhesion-promoting layer C,
• wherein the layer C comprises, based on the total weight of the layer C:
• from 0.0 to 95.0 wt.-% of a polymethyl(meth)acrylate;
• from 0.0 to 75.0 wt.-% of one or several impact modifiers;
• from 0.0 to 5.0 wt.-% of a UV-absorber;
• from 0.0 to 5.0 wt.-% of one or several UV-stabilizers;
• and
• from 5.0 to 80.0 wt.-% of an adhesion-promoting copolymer comprising
• (i) from 70.0 to 95.0 wt.-% methyl methacrylate;
• (ii) from 0.5 to 15.0 wt.-% maleic anhydride;
• and
• (iii) from 0.0 to 25.0 wt.-% of other vinyl-copolymerizable monomers having no functional groups other than the vinyl function, based on the weight of the adhesion-promoting copolymer;
• wherein a cumulative content of the polymethyl(meth)acrylate and of one or several impact modifiers in the layer C is at least 20.0 wt.-% and not more than 95.0 wt.-%, based on the weight of the layer C;
• and
• wherein the layer B comprises less than 3.0 wt.-%, based on the weight of the layer B, of said adhesion-promoting copolymer.

21:

• The foil according to claim 20, further comprising a fluoropolymer-based layer D, which is adjacent to the layer A, the layer D comprising, based on the total weight of the layer D:
• from 40.0 to 100.0 wt.-% of at least one fluoropolymer;
• from 0.0 to 60.0 wt.-% of a polymethyl(meth)acrylate;
• and
• from 0.0 to 30.0 wt.-% of substantially spherical glass beads.

24:

• The foil according to claim 23, wherein
• the layer A comprises from 0.5 to 3.0 wt-%, based on the weight of the layer A, of a triazine type compound as a first UV absorber;
• and
• the layer B comprises from 0.5 to 4.0 wt.-%, based on the weight of the layer B, of a benzotriazole type compound as a second UV absorber.

26:

• The foil according to claim 25, wherein the polymethyl(meth)acrylate is polymethyl methacrylate having an average molar weight Mw of from 80 000 g/mol to 220 000 g/mol and is obtainable by polymerization of a composition whose polymerizable constituents comprise, based on the weight of the polymerizable composition:
• (a) from 50.0 to 99.9 wt.-% of methyl methacrylate,
• (b) from 0.1 to 50.0 wt.-% of an acrylic acid ester of a C1-C4 alcohol, and
• (c) from 0.0 to 10.0 wt.-% of at least one further monomer co-polymerizable with the monomers (a) and (b).

27:

• The foil according to claim 26, wherein
• the layer A has a thickness from 10.0 μm to 100.0 μm;
• and
• the layer B has a thickness from 10.0 μm to 80.0 μm;
• the layer C, if present, has a thickness from 1.0 μm to 20.0 μm;
• the layer D, if present, has a thickness from 1.0 μm to 40.0 μm;
• and
• the layer E, if present, has a thickness from 10.0 μm to 80.0 μm.

31:

• A coated article having an outer surface and comprising a substrate which is at least partially covered by a foil according to claim 18, wherein the foil is optionally a co-extruded foil and comprises the following layers located in the following order, starting from the outer surface:
• optionally, layer D;
• the layer A;
• optionally, layer E;
• the layer B;
• and
• optionally, layer C;
• wherein the adhesion-promoting layer C comprises, based on the total weight of the layer C:
• from 0.0 to 95.0 wt.-% of a polymethyl(meth)acrylate;
• from 0.0 to 75.0 wt.-% of one or several impact modifiers;
• from 0.0 to 5.0 wt.-% of a UV-absorber;
• from 0.0 to 5.0 wt.-% of one or several UV-stabilizers;
• and
• from 5.0 to 80.0 wt.-% of an adhesion-promoting copolymer comprising
• (i) from 70.0 to 95.0 wt.-% methyl methacrylate;
• (ii) from 0.5 to 15.0 wt.-% maleic anhydride;
• and
• (iii) from 0.0 to 25.0 wt.-% of other vinyl-copolymerizable monomers having no functional groups other than the vinyl function, based on the weight of the adhesion-promoting copolymer;
• wherein a cumulative content of the polymethyl(meth)acrylate and of one or several impact modifiers in the layer C is at least 20.0 wt.-% and not more than 95.0 wt.-%, based on the weight of the layer C;
• and
• wherein fluoropolymer-based layer D, which is adjacent to the layer A, comprises, based on the total weight of the layer D:
• from 40.0 to 100.0 wt.-% of at least one fluoropolymer;
• from 0.0 to 60.0 wt.-% of a polymethyl(meth)acrylate;
• and
• from 0.0 to 30.0 wt.-% of substantially spherical glass beads;
• and
• wherein layer E, which is located between the layer A and the layer B, comprises a combination of the first UV absorber and the second UV absorber.