Fluoropolymer containing laminates
The multilayer film serves as a laminate. The film is a multilayered structure that, in its base form, encompasses an intermediate layer with first and second outer layer affixed to opposing sides of the intermediate layer. The first outer layer is a semi-crystalline fluoropolymer. The intermediate layer includes a polyester and the second outer layer is an olefinic polymer. The layers are bonded together in the noted order to provide the multilayer film.
1. A multilayer film comprising:
a first outer layer of a semi-crystalline fluoropolymer with a tensile modulus of less than 100,000 psi;
an intermediate layer of a polyester having at least two planar directions and a first and second surface, wherein the intermediate layer has a shrinkage of less than about 1% in each planar direction when held for 15 minutes at 150° C. measured in accordance with ASTM 2305-02; and
a second outer layer of an olefinic polymer, wherein the first outer layer and the second outer layer are bonded to opposing sides of the intermediate layer.
2. A multilayer film of claim 1 wherein the first outer layer comprises interpolymerized units of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride.
3. A multilayer film of claim 1 wherein the first outer layer comprises interpolymerized units of tetrafluoroethylene and ethylene.
4. The multilayer film of claim 1 further comprising applying a tie layer between the first layer and the intermediate layer, the second layer and intermediate layer, or both.
5. A multilayer film of claim 1 wherein the intermediate layer is polyethylene terephthalate.
6. A multilayer film of claim 1 wherein the second outer layer comprises interpolymerized units of ethylene vinyl actetate.
7. A multilayer film of claim 1 wherein the thickness of the second outer layer is greater than or about twice the combined thickness of the first outer layer and the intermediate layer.
8. A multilayer film of claim 1 wherein the thickness of the multilayer film is greater than 15 mils.
9. A multilayer film of claim 1 wherein the fluoropolymer has a tensile modulus of less than 80,000 psi.
10. A multilayer film of claim 1 wherein the shrinkage rate of the multilayer film is less than 1% at 150° C. when held for 15 minutes measured in accordance with ASTM 2305-02.
11. An article comprising the multilayer film of claim 1 applied to a substrate.
12. The article of claim 11 , wherein the substrate is a solar cell.
13. The article of claim 12 , wherein the substrate is a backing layer on the solar cell.