Solar cell sealing material and solar cell module

Abstract

A solar cell sealing material of the present invention is a solar cell sealing material that is used to seal a solar cell element and includes an ethylene.α-olefin copolymer, an organic peroxide (A) having a one-hour half-life temperature in a range of equal to or higher than 100° C. and equal to or lower than 130° C., and an organic peroxide (B) having a one-hour half-life temperature in a range of higher than 130° C. and equal to or lower than 160° C., and a ratio (X2/X1) of a content X2 of the organic peroxide (B) to a content X1 of the organic peroxide (A) in the solar cell sealing material is equal to or more than 0.05 and equal to or less than 1.10.

1 . A solar cell sealing material that is used to seal a solar cell element, the solar cell sealing material comprising:
 an ethylene.α-olefin copolymer;   an organic peroxide (A) having a one-hour half-life temperature in a range of equal to or higher than 100° C. and equal to or lower than 130° C.; and   an organic peroxide (B) having a one-hour half-life temperature in a range of higher than 130° C. and equal to or lower than 160° C.,   wherein a ratio (X 2 /X 1 ) of a content X 2  of the organic peroxide (B) to a content X 1  of the organic peroxide (A) in the solar cell sealing material is equal to or more than 0.05 and equal to or less than 1.10.   
     
     
         2 . The solar cell sealing material according to  claim 1 ,
 wherein MFR of the ethylene.α-olefin copolymer, which is on the basis of ASTM D1238 and measured under conditions of 190° C. and a load of 2.16 kg, is equal to or more than 0.1 g/10 minutes and less than 10 g/10 minutes.   
     
     
         3 . The solar cell sealing material according to  claim 1 ,
 wherein a total amount of the content X 1  of the organic peroxide (A) and the content X 2  of the organic peroxide (B) in the solar cell sealing material is equal to or more than 0.1 parts by mass and equal to or less than 3.0 parts by mass with respect to 100 parts by mass of the ethylene.α-olefin copolymer.   
     
     
         4 . The solar cell sealing material according to  claim 1 ,
 wherein a gel fraction is equal to or more than 55% and equal to or less than 100%.   
     
     
         5 . The solar cell sealing material according to  claim 1 ,
 wherein the organic peroxide (A) includes at least one kind selected from peroxyketals and peroxycarbonates.   
     
     
         6 . The solar cell sealing material according to  claim 5 ,
 wherein the organic peroxide (A) includes peroxyketals, and   
       the peroxyketals include 1,1-di(t-butylperoxy)cyclohexane. 
     
     
         7 . The solar cell sealing material according to  claim 1 ,
 wherein the organic peroxide (B) includes dialkyl peroxides.   
     
     
         8 . The solar cell sealing material according to  claim 7 ,
 wherein the organic peroxide (B) includes dialkyl peroxides, and   the dialkyl peroxides include 2,5-dimethyl-2,5-di(t-butylperoxy)hexane.   
     
     
         9 . The solar cell sealing material according to  claim 1 ,
 wherein the ethylene.α-olefin copolymer satisfies at least one of requirements a1) and a2) below,   a1) a density measured on the basis of ASTM D1505 is 0.865 to 0.895 g/cm 3 , and   a2) a shore A hardness measured on the basis of ASTM D2240 is 60 to 95.   
     
     
         10 . The solar cell sealing material according to  claim 1 , further comprising:
 a silane coupling agent,   wherein a content of the silane coupling agent in the solar cell sealing material is equal to or more than 0.1 parts by mass and equal to or less than 5.0 parts by mass with respect to 100 parts by mass of the ethylene.α-olefin copolymer.   
     
     
         11 . The solar cell sealing material according to  claim 1 , further comprising:
 a crosslinking aid,   wherein a content of the crosslinking aid in the solar cell sealing material is equal to or more than 0.1 parts by mass and equal to or less than 3.0 parts by mass with respect to 100 parts by mass of the ethylene.α-olefin copolymer.   
     
     
         12 . The solar cell sealing material according to  claim 1 ,
 wherein the solar cell sealing material has a sheet shape.   
     
     
         13 . A solar cell module comprising:
 a front surface-side transparent protective member;   a rear surface-side protective member;   a solar cell element; and   a sealing layer which is made of a crosslinked substance of the solar cell sealing material according to  claim 1  and seals the solar cell element between the front surface-side transparent protective member and the rear surface-side protective member.