Multiple layer film and composite material produced therefrom
View Patent ↗A film comprising the following layers: I. a layer based on a polyamide whose monomer units contain an average of at least 8 carbon atoms, II. an immediately adjacent layer composed of a moulding composition comprising a polyamide as in I. and a copolymer having functional groups is used for the production of a composite with a substrate which comprises PA6, PA66, PA6/66 or PPA, giving secure adhesion.
1. A film, comprising:
a polyamide layer comprising at least 40% by weight of at least one polyamide selected from the group consisting of PA6, PA66, PA6/66 and a copolyamide, wherein the copolyamide is obtained from PA6, PA66 and PA6/66 and comprises at most 50% of total monomer units replaced by aromatic monomer units;
a second layer formed directly on the polyamide layer, wherein the second layer is obtained from a molding composition consisting of a polyamide composition (a) in an amount of from 50 to 99 parts by weight, a copolymer (b) in an amount of from 1 to 50 parts by weight with respect to a total amount of the polyamide composition (a) and the copolymer (b), and optionally at least one additive selected from the group consisting of a flame retardant, a stabilizer, an antistatic agent, a filler, a dye, and a pigment; and
a first layer formed directly on the second layer, wherein the first layer comprises a molding composition which comprises at least 60% by weight of a polyetheresteramide, the monomer units of the polyamide of the polyetheresteramide comprise an average of at least 8 carbon atoms,
wherein:
the polyamide composition (a) consists of a polyamide (α) in an amount of from 40 to 100% by weight, and a polyamide (β) in an amount of 0 to 60% with respect to a total amount of the polyamide (α) and the polyamide (β);
the polyamide (α) is PA612;
the polyamide (β) is at least one selected from the group consisting of PA6, PA66, PA6/66, and a copolyamide, wherein the copolyamide is obtained from PA6, PA66 and PA6/66 and comprises at most 50% of total monomer units replaced by aromatic monomer units;
the copolymer (b) comprises a first monomer unit in an amount of from 70 to 99.9% by weight and a second monomer unit in an amount of 0.1 to 30% by weight;
the first monomer unit is a monomer unit of at least one vinyl compound selected from the group consisting of an acrylic acid derivative, a methacrylic acid derivative, an α-olefin and a vinylaromatic compound; and
the second monomer unit comprises a functional group selected from the group consisting of a carboxylic anhydride group, an epoxy group, and an oxazoline group.
2. The film according to claim 1 , wherein the molding composition of the first layer comprises at least one of a pigment, a dye, and a metal flake.
3. The film according to claim 1 , further comprising an outer layer.
4. The film according to claim 1 , wherein the copolymer (b) is a polyolefin having an unsaturated anhydride grafted thereon.
5. The film according to claim 4 , wherein the polyolefin is an ethylene-propylene rubber or an ethylene-propylene-diene rubber.
6. The film according to claim 1 , wherein the copolymer (b) comprises the first monomer unit in an amount of from 85 to 99% by weight and the second monomer units in an amount of 1 to 15% by weight.
7. The film according to claim 1 , wherein the first monomer unit of the copolymer (b) is represented by formula (III):
wherein R 1 is H or CH 3 .
8. The film according to claim 1 , wherein the second monomer unit of the copolymer (b) is represented by formula (VII):
wherein R 1 is H or CH 3 .
9. The film according to claim 1 , wherein the second monomer unit of the copolymer (b) is represented by formula (VIII):
wherein R 1 is H or CH 3 .
10. The film according to claim 1 , further comprising an outer layer on the first layer, wherein the outer layer comprises at least one of a polyamide, an acrylate polymer, a fluoropolymer or a clear polyurethane-based lacquer.
11. The film according to claim 10 , wherein the polymer constitution of the outer layer is the same as the polymer constitution of the first layer.
12. The film according to claim 1 , wherein the molding composition consists of the polyamide composition (a) in an amount of from 50 to 99 parts by weight, the copolymer (b) in an amount of from 1 to 50 parts by weight with respect to a total amount of the polyamide composition (a) and the copolymer (b), and optionally at least one additive selected from the group consisting of a stabilizer, a dye and a pigment.
13. A method of preparing the film according to claim 1 , the method comprising forming the second layer directly on the polyamide layer and forming the first layer directly on the second layer.
14. A composite part, comprising the film of claim 1 applied to a polyamide substrate.
15. The composite part according to claim 14 , wherein the film is applied on the polyamide substrate by adhesive bonding, pressing, lamination or extrusion, or by an injection-molding method, foaming method, or compression-molding method for reverse coating.
16. The composite part according to claim 14 , wherein the composite part is an engine cover, a battery cover, a battery casing or a cover or a casing for electronics components.
17. The composite part according to claim 14 , wherein:
the polymer constitution of the polyamide (β) is the same as the polymer constitution of the polyamide layer.
18. The composite part according to claim 14 , wherein the film is applied directly to the polyamide substrate.
19. A method of preparing the composite part according to claim 14 , the method comprising applying the film on the polyamide substrate.