Multilayered film and photovoltaic module including the same

Patent metadata

Field	Value
Publication number	US-9379264-B2
Application number	US-201313891057-A
Country	US
Kind code	B2
Filing date	May 9, 2013
Priority date	Nov 10, 2010
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A multilayered film, a back sheet for a photovoltaic cell, methods of manufacturing the film and cell, and a photovoltaic module including the film and cell are provided. The multilayered film includes a resin layer formed on a substrate, and the resin layer contains a fluorine-based polymer and a reactive functional group having an equivalent weight of 30,000 or less. The resin layer containing the fluorine-based polymer has good durability and weatherability and is highly adhesive to the substrate at an interface between the resin layer and the substrate. Also, since a drying process may be performed at a low temperature during manufacture of the multilayered film, manufacturing costs may be reduced, productivity may be increased, and degradation in the quality of products due to thermal deformation or thermal shock may be prevented. The multilayered film may be effectively used as, for example, a back sheet for various photovoltaic modules.

First claim

What is claimed is:

1. A multilayered film comprising:
a substrate; and
a resin layer directly disposed on the substrate and including a fluorine-based polymer and an acrylic polymer containing a reactive functional group,
wherein an equivalent weight of the reactive functional group with respect to a mixture of the fluorine-based polymer and the acrylic polymer of the resin layer is 2,000 to 20,000,
wherein the acrylic polymer has a weight-average molecular weight of a hundred thousand to five million, and
wherein the acrylic polymer is contained at a content of 2 to 30% by weight in the mixture of the fluorine-based polymer and the acrylic polymer containing the reactive functional group, which are included in the resin layer.

2. The film of claim 1 , wherein the reactive functional group includes at least one selected from the group consisting of a carboxyl group, an amide group, an amino group, an epoxy group, a hydroxyl group, an acid anhydride group, an isocyanate group, a sulfonic acid group, an aziridine group, an amine group, a urea group, a phosphoric acid group, a cyano group, a cyanate group, an imidazole group, an oxazoline group, and an imine group.

3. The film of claim 1 , wherein the acrylic polymer containing the reactive functional group is a copolymer of at least one selected from the group consisting of (meth)acrylate, alkyl (meth)acrylate, and isobornyl (meth)acrylate and at least one monomer containing a reactive functional group.

4. The film of claim 3 , wherein the alkyl (meth)acrylate includes at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate.

5. The film of claim 3 , wherein the monomer containing the reactive functional group includes at least one selected from the group consisting of a carboxyl group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, a hydroxyl group-containing monomer, an acid anhydride group-containing monomer, an isocyanate group-containing monomer, a sulfonic acid group-containing monomer, an aziridine group-containing monomer, an amine group-containing monomer, a urea group-containing monomer, a phosphoric acid group-containing monomer, a cyano group-containing monomer, a cyanate group-containing monomer, an imidazole group-containing monomer, an oxazoline group-containing monomer, and an imine group-containing monomer.

6. The film of claim 3 , wherein the monomer containing the reactive functional group includes a carboxyl group-containing monomer, an epoxy group-containing monomer, or an oxazoline group-containing monomer.

7. The film of claim 3 , wherein the monomer containing the reactive functional group includes at least one selected from the group consisting of glycidyl (meth)acrylate, glycidyl alkyl (meth)acrylate, (meth)acrylic acid, isocyanato alkyl (meth)acrylate, (meth)acrylonitrile, cyclohexyl maleimide, hydroxy alkyl (meth)acrylate, maleic anhydride, p-toluene sulfonic acid, phosphoric acid, (meth)acrylamide, aminoalkyl (meth)acrylate, vinyl imidazole, and 2-isopropenyl-2-oxazoline.

8. The film of claim 3 , wherein the acrylic polymer containing the reactive functional group further includes a polymerizable monomer.

9. The film of claim 8 , wherein the polymerizable monomer includes styrene, chlorostyrene, chloromethyl styrene, or methyl styrene.

10. The film of claim 1 , wherein the fluorine-based polymer includes a homopolymer, a copolymer, or a mixture thereof, which includes, in a polymerized form, at least one monomer selected from the group consisting of vinylidene fluoride (VDF), vinyl fluoride (VF), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), chlorotrifluoroethylene (CTFE), trifluoroethylene, hexafluoroisobutylene, perfluoro-butylethylene, perfluoro(methylvinylether) (PMVE), perfluoro(ethylvinylether) (PEVE), perfluoro(propylvinylether) (PPVE), perfluoro(hexylvinylether) (PHVE), perfluoro-2,2-dimethyl-1,3-dioxole (PDD), and perfluoro-2-methylene-4-methyl-1,3-dioxolane (PMD).

11. The film of claim 1 , wherein the fluorine-based polymer includes a homopolymer or copolymer containing vinyl fluoride (VF) in a polymerized form; a homopolymer or copolymer containing vinylidene fluoride (VDF) in a polymerized form; or a mixture thereof.

12. The film of claim 1 , wherein the fluorine-based polymer includes a copolymer of vinylidene fluoride (VDF) or vinyl fluoride (VF) and at least one comonomer selected from the group consisting of tetrafluoroethylene (TFE), hexafluoropropylene (HFP), chlorotrifluoroethylene (CTFE), trifluoroethylene, hexafluoroisobutylene, perfluoro-butylethylene, PMVE, PEVE, PPVE, PHVE, PDD, and PMD; or mixture thereof.

13. The film of claim 12 , wherein the comonomer is contained at a content of 0.5 to 50% by weight.

14. The film of claim 1 , wherein the fluorine-based polymer has a weight-average molecular weight (MW) of 50,000 to 1,000,000.

15. The film of claim 1 , wherein the fluorine-based polymer has a melting point of 80° C. to 175° C.

16. The film of claim 1 , wherein the resin layer including the fluorine-based polymer and the acrylic polymer containing the reactive functional group contains 50% or less by weight of the acrylic polymer containing the reactive functional group.

17. The film of claim 1 , wherein the substrate is aluminum (Al), iron (Fe); or a single sheet, a stacked sheet, or a co-extrusion of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polybutylene terephthalate (PBT).

18. The film of claim 1 , wherein at least one surface of the substrate is treated with at least one selected from the group consisting of plasma, corona, primer, a coupling agent, and heat.

19. The film of claim 1 , wherein the substrate has a thickness of 50 μm to 500 μm.

20. The film of claim 1 , wherein the resin layer including the fluorine-based polymer and the acrylic polymer containing the reactive functional group has a thickness of approximately 3 μm to 50 μm.

21. The film of claim 1 , wherein the resin layer including the fluorine-based polymer and the acrylic polymer containing the reactive functional group further includes a pigment, a filler, an ultraviolet (UV) stabilizer, a thermal stabilizer, or barrier particles.

22. The film of claim 1 , wherein the resin layer including the fluorine-based polymer and the acrylic polymer containing the reactive functional group is a coating layer formed by coating a resin composition.

23. A back sheet for a photovoltaic cell, comprising:
a substrate; and
a resin layer disposed on the substrate and including a fluorine-based polymer and an acrylic polymer containing a reactive functional group,
wherein an equivalent weight of the reactive functional group with respect to a mixture of the fluorine-based polymer and the acrylic polymer of the resin layer is 2,000 to 20,000,
wherein the acrylic polymer has a weight-average molecular weight of a hundred thousand to five million, and
wherein the acrylic polymer is contained at a content of 2 to 30% by weight in the mixture of the fluorine-based po

Assignees

• Lg Chemical Ltd

Inventors

• Kim Hyun Cheol
• Kwon Yoon Kyung
• Ko Hyun Seong
• Park Hyo Soon
• Ahn Do Won

Classifications

• C08J7/0427

  with only one layer of a composition containing a polymer binder (with more layers C08J7/042) · CPC title

• B32B2307/7242

  Non-permeable · CPC title

• B32B2255/10

  on synthetic resin layer or on natural or synthetic rubber layer · CPC title

• B32B27/36

  comprising polyesters · CPC title

• B32B2255/26

  Polymeric coating · CPC title