Composition, multilayer sheets made therefrom, and methods for making and using the same

Patent metadata

Field	Value
Publication number	US-9441106-B2
Application number	US-201113294523-A
Country	US
Kind code	B2
Filing date	Nov 11, 2011
Priority date	Nov 11, 2011
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

In an embodiment, a photovoltaic module, comprises a transparent superstrate; a backsheet, wherein the backsheet comprises a core layer comprising a core composition formed from a first polycarbonate comprising dimethyl bisphenol cyclohexane carbonate repeat units and bishpenol-A, wherein the first polycarbonate has the structure

wherein the dimethyl bisphenol cyclohexane carbonate repeat units are present in an amount of 10 wt. % to 50 wt. %, based on the total repeat units in the core composition; and a second polycarbonate selected from the group consisting of a bisphenol-A polycarbonate homopolymer, a polyphthalate carbonate copolymer, a polycarbonate copolymer comprising 2-phenyl-3,3-bis(4-hydroxyphenyl) phthalimidine carbonate and bisphenol-A carbonate repeat units, a polycarbonate copolymer comprising bisphenol-A carbonate and tetrabromobisphenol A carbonate repeat units, and combinations comprising at least one of the foregoing; and a photovoltaic cell between the superstrate and the backsheet.

First claim

The invention claimed is:

1. A multilayer sheet, comprising:
a core layer formed from a core composition comprising
a first polycarbonate comprising dimethyl bisphenol cyclohexane carbonate repeat units (X) and bisphenol-A carbonate repeat units (Y), where the first polycarbonate has the structure

wherein the dimethyl bisphenol cyclohexane carbonate repeat units are present in an amount of 10 wt. % to 40 wt. %, based on the total repeat units in the core composition;
a second polycarbonate comprising a polyphthalate carbonate copolymer comprising a bisphenol-A carbonate block (x) and an aromatic ester block (y) having the structure and

wherein the second polycarbonate does not comprise an isophthalate bisphenol-A ester block; and
a third polycarbonate comprising a bisphenol-A polycarbonate homopolymer; and

a first cap layer disposed on a surface of the core layer;
wherein the multilayer sheet is hydrothermally stable.

2. The multilayer sheet of claim 1 , wherein the second polycarbonate is present in an amount of 20 wt. % to 50 wt. %, and the third polycarbonate is present in an amount of 10 wt. % to 50 wt. %, based on a total weight of the composition of 100 wt. %.

3. The multilayer sheet of claim 2 , wherein the second polycarbonate is present in an amount of 40 wt. % to 50 wt. %, and the third polycarbonate is present in an amount of 10 wt. % to 25 wt. %, based on a total weight of the composition of 100 wt. %.

4. The multilayer sheet of claim 1 , wherein the thermal shrinkage of the multilayer sheet is less than 1% along the machine direction and the transverse direction after a thermal treatment at 150° C. for 30 minutes.

5. The multilayer sheet of claim 1 , wherein the sheet has greater than or equal to 30% retention of puncture resistance after a pressure cooker test at a temperature of 121° C., saturated water steam pressure of 1.2 bars, and 100% relative humidity for 72 hours.

6. The multilayer sheet of claim 1 , wherein the first cap layer comprises at least one of a polycarbonate and a UV light absorbing stabilizer, or a resorcinol polyarylate carbonate copolymer.

7. The multilayer sheet of claim 1 , further comprising a second cap layer, wherein the core layer is disposed between the first cap layer and the second cap layer, wherein the second cap layer comprises at least one of bisphenol-A polycarbonate, polycarbonate copolymers, polyethylene, or polypropylene.

8. The multilayer sheet of claim 1 , wherein the first cap layer comprises a fluoropolymer selected from the group consisting of polyvinylfluoride, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethyelene, ethylene-chlorotrifluoroethylene copolymer, tetrafluoroethylene hexafluoropropylene vinylidenefluoride, and combinations thereof.

9. The multilayer sheet of claim 1 , wherein the sheet has a thermal shrinkage of less than or equal to 3%.

10. The multilayer sheet of claim 1 , wherein the sheet has a water vapor transmission rate of less than or equal to 15 g/m 2 −24 hour.

11. The multilayer sheet of claim 1 , wherein the sheet passes a minimum of 1,000 hours of a damp heat test at conditions of 85° C. and 85% relative humidity.

12. The multilayer sheet of claim 1 , wherein the multilayer sheet has a retention of puncture resistance after environmental exposure of greater than or equal to 50%.

13. The multilayer sheet of claim 12 , wherein the retention of puncture resistance after environmental exposure is greater than or equal to 60%.

14. A method of making a multilayer sheet, comprising:
co-extruding a core layer and a first cap layer, wherein the core layer comprises a core composition comprising
a first polycarbonate comprising dimethyl bisphenol cyclohexane carbonate repeat units (X) and bisphenol-A carbonate repeat units (Y), wherein the first polycarbonate has the structure

wherein the dimethyl bisphenol cyclohexane carbonate repeat units are present in an amount of 10 wt. % to 40 wt. %, based on the total repeat units in the core composition;
a second polycarbonate comprising a polyphthalate carbonate copolymer comprising a bisphenol-A carbonate block (x) and an aromatic ester block (y) having the structure

wherein the second polycarbonate does not comprise an isophthalate bisphenol-A ester block; and
a third polycarbonate comprising a bisphenol-A polycarbonate homopolymer; and

wherein the first cap layer is disposed on a surface of the core layer and wherein the first cap layer comprises a member selected from the group consisting of polycarbonate and a UV light absorbing stabilizer, a resorcinol polyarylate carbonate copolymer, and combinations thereof;
wherein the multilayer sheet is hydrothermally stable.

15. The method of claim 14 , further comprising co-extruding a second cap layer comprising polycarbonate, wherein the core layer is disposed between the first cap layer and the second cap layer.

16. The method of claim 14 , further comprising laminating a second cap layer comprising a polyolefin to the core layer, wherein an adhesive layer is disposed between the core layer and the second cap layer, and wherein the core layer is disposed between the first cap layer and the adhesive layer.

17. A photovoltaic module, comprising:
a transparent superstrate;
a backsheet, wherein the backsheet comprises a core layer comprising a core composition comprising a first polycarbonate comprising dimethyl bisphenol cyclohexane carbonate repeat units (X) and bisphenol-A carbonate repeat units (Y), wherein the first polycarbonate has the structure

wherein the dimethyl bisphenol cyclohexane carbonate repeat units are present in an amount of 10 wt. % to 40 wt. %, based on the total repeat units in the core composition;
a second polycarbonate comprising a polyphthalate carbonate copolymer comprising a bisphenol-A carbonate block (x) and an aromatic ester block (y) having the structure

wherein the second polycarbonate does not comprise an isophthalate bisphenol-A ester block; and
a third polycarbonate comprising a bisphenol-A polycarbonate homopolymer; and

a first cap layer disposed on a surface of the core layer; and
a photovoltaic cell between the superstrate and the backsheet;
wherein the backsheet is hydrothermally stable.

18. The photovoltaic module of claim 17 , wherein the first cap layer comprises polycarbonate and a UV light absorbing stabilizer.

19. The photovoltaic module of claim 18 , further comprising a second cap layer, wherein the core layer is disposed between the first cap layer and the second cap layer, wherein the second cap layer comprises a member selected from the group consisting of polycarbonate, ethylene vinyl acetate copolymer with a vinyl acetate content of 2 wt. % to 10 wt. %, polyethylene, polypropylene, cyclic olefin copolymer, and combi

Assignees

• Zhou Jian
• Van Zyl Andries Jakobus Petrus
• Pai-Paranjape Vandita
• Tryson Glen Robert
• Niemeyer Matthew Frank
• Sabic Global Technologies Bv

Inventors

• Zhou Jian
• Van Zyl Andries Jakobus Petrus
• Pai-Paranjape Vandita
• Tryson Glen Robert
• Niemeyer Matthew Frank

Classifications

• H10F19/85

  Protective back sheets · CPC title

• B32B2457/12

  Photovoltaic modules · CPC title

• B32B27/365

  comprising polycarbonates · CPC title

• B32B2270/00

  Resin or rubber layer containing a blend of at least two different polymers · CPC title

• B32B27/08 Primary

  of synthetic resin · CPC title