Encapsulating material for solar cell and solar cell module
| Title: | Encapsulating material for solar cell and solar cell module |
|---|---|
| Patent Number: | 9,349,895 |
| Publication Date: | May 24, 2016 |
| Appl. No: | 13/882218 |
| Application Filed: | October 31, 2011 |
| Abstract: | An encapsulating material for solar cell excellent in a balance among properties including transparency, flexibility, adhesiveness, heat resistance, appearance, crosslinking properties, electrical properties and calender moldability. The encapsulating material includes an ethylene/α-olefin copolymer satisfying the following requirements: (a1) the content ratio of structural units derived from ethylene is from 80 to 90 mol % and the content ratio of structural units derived from α-olefin having 3 to 20 carbon atoms is from 10 to 20 mol %; (a2) MFR is equal to or more than 2 g/10 minutes and less than 10 g/10 minutes as measured under the conditions of a temperature of 190 degrees centigrade and a load of 2.16 kg in accordance with ASTM D1238; (a3) the density is from 0.865 to 0.884 g/cm3 as measured in accordance with ASTM D1505; and (a4) the shore A hardness is from 60 to 85 as measured in accordance with ASTM D2240. |
| Inventors: | Ikenaga, Shigenobu (Chiba, JP); Takeuchi, Fumito (Chiba, JP); Watanabe, Keiji (Ichihara, JP); Ito, Tomoaki (Ichihara, JP) |
| Assignees: | MITSUI CHEMICALS, INC. (Tokyo, JP), MITSUI CHEMICALS TOHCELLO, INC. (Tokyo, JP) |
| Claim: | 1. A solar cell module comprising: a transparent surface protective member; a back surface protective member; a solar cell element; and an encapsulating layer for encapsulating said solar cell element between said transparent surface protective member and said back surface protective member to be formed by crosslinking an encapsulating material for solar cell, wherein the encapsulating layer is in direct contact with at least one side of the solar cell element, and the encapsulating material for solar cell comprises an ethylene/α-olefin copolymer satisfying the following requirements (a1) to (a4) and (a11): (a1) the content ratio of structural units derived from ethylene is from 80 to 90 mol % and the content ratio of structural units derived from α-olefin having 3 to 20 carbon atoms is from 10 to 20 mol %; (a2) MFR is equal to or more than 2 g/10 minutes and less than 10 g/10 minutes as measured under the conditions of a temperature of 190 degrees centigrade and a load of 2.16 kg in accordance with ASTM D1238; (a3) the density is from 0.865 to 0.884 g/cm 3 as measured in accordance with ASTM D1505; (a4) the shore A hardness is from 60 to 85 as measured in accordance with ASTM D2240; and (a11) the extracted amount of said ethylene/α-olefin copolymer in methyl acetate is equal to or less than 5.0 weight %. |
| Claim: | 2. The solar cell module according to claim 1 , wherein the encapsulating material for solar cell further satisfies the following requirement (a5): (a5) the volume resistivity is from 1.0×10 13 to 1.0×10 18 Ω·cm as measured at a temperature of 100 degrees centigrade with an applied voltage of 500V in accordance with JIS K6911. |
| Claim: | 3. The solar cell module according to claim 1 , wherein said ethylene/α-olefin copolymer further satisfies the following requirement (a6): (a6) the content of aluminum element in said ethylene/α-olefin copolymer is from 10 to 500 ppm. |
| Claim: | 4. The solar cell module according to claim 2 , wherein said ethylene/α-olefin copolymer further satisfies the following requirement (a6): (a6) the content of aluminum element in said ethylene/α-olefin copolymer is from 10 to 500 ppm. |
| Claim: | 5. The solar cell module according to claim 1 , wherein the encapsulating material for solar cell further contains organic peroxide having a one-minute half-life temperature in the range of 100 to 170 degrees centigrade in an amount of 0.1 to 3 weight parts, based on 100 weight parts of said ethylene/α-olefin copolymer. |
| Claim: | 6. The solar cell module according to claim 1 , wherein said ethylene/α-olefin copolymer is polymerized in the presence of a catalyst for olefin polymerization comprising a metallocene compound, and at least one compound selected from the group consisting of an organic aluminumoxy compound and an organic aluminum compound. |
| Claim: | 7. The solar cell module according to claim 1 , wherein the encapsulating material for solar cell comprises an ethylene resin composition containing a silane coupling agent in an amount of 0.1 to 5 weight parts, based on 100 weight parts of said ethylene/α-olefin copolymer. |
| Claim: | 8. The solar cell module according to claim 7 , wherein said ethylene resin composition further comprises at least one kind selected from the group consisting of an ultraviolet absorber, a heat-resistant stabilizer and a hindered amine type light stabilizer in an amount of 0.005 to 5 weight parts, based on 100 weight parts of said ethylene/α-olefin copolymer. |
| Claim: | 9. The solar cell module according to claim 7 , wherein said ethylene resin composition further comprises a crosslinking aid in an amount of 0.05 to 5 weight parts, based on 100 weight parts of said ethylene/α-olefin copolymer. |
| Claim: | 10. The solar cell module according to claim 1 , the encapsulating material for solar cell is obtained by melt-kneading said ethylene/α-olefin copolymer and an additive and then calender-molding the melt-kneaded mixture at the calender molder in a sheet form. |
| Claim: | 11. The solar cell module according to claim 1 , wherein, for said ethylene/α-olefin copolymer, (a7) the B value determined from the 13 C-NMR spectrum and the following equation (1) is from 0.9 to 1.5, and (a8) the intensity ratio of Tαβ to Tαα (Tαβ/Tαα) in the 13 C-NMR spectrum is equal to or less than 1.5: B Value=[ P OE ]/(2 ×[P O ]×[P E ]) (1) wherein, in the equation (1), [P E ] represents the molar fraction of structural units derived from ethylene contained in said ethylene/α-olefin copolymer; [P O ] represents the molar fraction of structural units derived from α-olefin having 3 to 20 carbon atoms contained in said ethylene/α-olefin copolymer; and [P OE ] represents the molar fraction of an α-olefin/ethylene chain contained in the total dyad chain. |
| Claim: | 12. The solar cell module according to claim 1 , wherein (a9) the molecular weight distribution (Mw/Mn) of said ethylene/α-olefin copolymer is in the range of 1.2 to 3.5 as measured by gel permeation chromatography (GPC). |
| Claim: | 13. The solar cell module according to claim 1 , wherein (a10) the content ratio of chlorine ion of said ethylene/α-olefin copolymer is equal to or less than 2 ppm as detected from an extract subjected to solid-phase extraction by ion chromatography. |
| Claim: | 14. The solar cell module according to claim 1 , wherein the encapsulating material for solar cell is in a sheet form. |
| Patent References Cited: | 5955198 September 1999 Hashimoto et al. 2001/0014718 August 2001 Kagami et al. 2003/0176124 September 2003 Koike et al. 2004/0186237 September 2004 Kagami et al. 2007/0071970 March 2007 Koike et al. 2007/0251572 November 2007 Hoya et al. 2007/0267059 November 2007 Nishijima et al. 2010/0108127 May 2010 Hayes 2010/0313956 December 2010 Nishijima et al. 2013/0000694 January 2013 Bunea et al. 1165529 November 1997 9-183871 July 1997 9-234815 September 1997 2000-289157 October 2000 2005-126571 May 2005 2006-210906 August 2006 2008-205448 September 2008 2010-053298 March 2010 2010-155915 July 2010 2010-258439 November 2010 WO 9710295 March 1997 WO 02/074532 September 2002 WO 2006/057361 June 2006 WO 2008/036708 March 2008 WO 2010/051422 May 2010 WO 2010/114028 October 2010 |
| Other References: | International Search Report (PCT/ISA/210) issued on Jan. 24, 2012, by the Japanese Patent Office as the International Searching Authority for International Application No. PCT/JP2011/006095. cited by applicant Japanese Office Action dated Apr. 12, 2013, issued in corresponding Japanese Patent Application No. 2012-541740 (3 pages). cited by applicant Extended Search report issued in corresponding European Application No. 11837740 on Nov. 20, 2014 (6 pages). cited by applicant Office Action issued in the corresponding Taiwanese Patent Application on May 13, 2015 (8 pages). cited by applicant |
| Assistant Examiner: | Branch, Catherine S |
| Primary Examiner: | Choi, Ling |
| Attorney, Agent or Firm: | Buchanan, Ingersoll & Rooney PC |
| Accession Number: | edspgr.09349895 |
| Database: | USPTO Patent Grants |
| Language: | English |
|---|