Electronic Device Module Comprising an Ethylene Multi-Block Copolymer

Abstract

An electronic device module comprises: A. At least one electronic device, e.g., a solar cell, and B. A polymeric material in intimate contact with at least one surface of the electronic device, the polymeric material comprising an ethylene multi-block copolymer. Typically, the polyolefin material is an ethylene multi-block copolymer with a density of less than about 0.90 grams per cubic centimeter (g/cc). The polymeric material can fully encapsulate the electronic device, or it can be laminated to one face surface of the device. Optionally, the polymeric material can further comprise a scorch inhibitor, and the copolymer can remain uncrosslinked or it can be crosslinked.

1 . An electronic device module comprising:
 A. At least one electronic device, and   B. An polymeric material in intimate contact with at least one surface of the electronic device, the polymeric material comprising (1) an ethylene multi-block copolymer with at least one property of (a) a molecular weight distribution of greater than about 1.3, (b) a density of less than about 0.90 g/cc, (c) a 2% secant modulus of less than about 150 megaPascal (mPa) as measured by ASTM D-882-02, (d) a melt point of less than about 125 C, (e) an α-olefin content of at least about 10 and less than about 80 weight percent (wt %) based on the weight of the copolymer, and (f) a Tg of less than about −35 C, (2) optionally, a free radical initiator, and (3) optionally, a co-agent.   
     
     
         2 . The module of  claim 1  in which the electronic device is a solar cell. 
     
     
         3 . The module of  claim 2  in which the free radical initiator is present in an amount of at least about 0.05 wt % based on the weight of the copolymer. 
     
     
         4 . The module of  claim 3  in which the coagent is present in an amount of at least about 0.05 wt % based on the weight of the copolymer. 
     
     
         5 . The module of  claim 4  in which the free radical initiator is a peroxide. 
     
     
         6 . The module of  claim 1  in which the polyolefin copolymer is crosslinked such that that the copolymer contains less than about 70 percent xylene soluble extractables as measured by ASTM 2765-95. 
     
     
         7 . The module of  claim 1  in which the polymeric material is in the form of a monolayer film in intimate contact with at least one face surface of the electronic device. 
     
     
         8 . The module of  claim 1  in which the polymeric material further comprises a scorch inhibitor in an amount from about 0.01 to about 1.7 wt %. 
     
     
         9 . The module of  claim 1  further comprising at least one glass cover sheet. 
     
     
         10 . The module of  claim 1  in which the polymeric material further comprises a polyolefin polymer grafted with an unsaturated organic compound containing at least one ethylenic unsaturation and at least one carbonyl group. 
     
     
         11 . The module of  claim 10  in which the unsaturated organic compound is maleic anhydride. 
     
     
         12 . The module of  claim 1  in which the ethylene multi-block copolymer is further characterized by at least one of (i) a molecular fraction that elutes between about 40 C and about 130 C when fractionated using TREF, characterized in that the fraction has a block index of at least 0.5 and up to about 1 and a MWD greater than about 1.3, and (ii) an average block index greater than zero and up to about 1.0 and an MWD greater than about 1.3. 
     
     
         13 . An electronic device module comprising:
 A. At least one electronic device, and   B. A polymeric material in intimate contact with at least one surface of the electronic device, the polymeric material comprising (1) an ethylene multi-block copolymer with at least one property of (a) a molecular weight distribution of greater than about 1.3, (b) a density of less than about 0.90 g/cc, (c) a 2% secant modulus of less than about 150 megaPascal (mPa) as measured by ASTM D-882-02, (d) a melt point of less than about 125 C, (e) an α-olefin content of at least about 10 and less than about 80 wt % based on the weight of the copolymer, and (f) a Tg of less than about −35 C, (2) a vinyl silane in an amount of at least about 0.1 wt % based on the weight of the copolymer, (3) free radical initiator in an amount of at least about 0.05 wt % based on the weight of the copolymer, and (4) optionally, a co-agent.   
     
     
         14 . The module of  claim 13  in which the electronic device is a solar cell. 
     
     
         15 . The module of  claim 14  in which the coagent is present in an amount of at least about 0.05 wt % based on the weight of the copolymer. 
     
     
         16 . The module of  claim 15  in which the free radical initiator is a peroxide. 
     
     
         17 . The module of  claim 16  in which the vinyl silane is at least one of vinyl tri-ethoxy silane and vinyl tri-methoxy silane. 
     
     
         18 . The module of  claim 13  in which the polyolefin copolymer is crosslinked such that that the copolymer contains less than about 70 percent xylene soluble extractables as measured by ASTM 2765-95. 
     
     
         19 . The module of  claim 13  in which the polymeric material is in the form of a monolayer film in intimate contact with at least one face surface of the electronic device. 
     
     
         20 . The module of  claim 13  in which the polymeric material further comprises a scorch inhibitor in an amount from about 0.01 to about 1.7 wt %. 
     
     
         21 . The module of  claim 13  in which the polymeric material further comprises a polyolefin polymer grafted with an unsaturated organic compound containing at least one ethylenic unsaturation and at least one carbonyl group. 
     
     
         22 . The module of  claim 21  in which the unsaturated organic compound is maleic anhydride. 
     
     
         23 . The module of  claim 13  in which the ethylene multi-block copolymer is further characterized by at least one of (i) a molecular fraction that elutes between about 40 C and about 130 C when fractionated using TREF, characterized in that the fraction has a block index of at least 0.5 and up to about 1 and a MWD greater than about 1.3, and (ii) an average block index greater than zero and up to about 1.0 and an MWD greater than about 1.3. 
     
     
         24 . An electronic device module comprising:
 A. At least one electronic device, and   B. A polymeric material in intimate contact with at least one surface of the electronic device, the polymeric material comprising an ethylene multi-block copolymer.   
     
     
         25 . An ethylene/non-polar alpha-olefin polymeric film characterized in that the film has (i) greater than or equal to 92% transmittance over the wavelength range of 400 to 1100 nanometers, and (ii) a water vapor transmission rate of less than about 50 grams per square meters per day (g/m 2 -day).