Use of carbon black for oxidative and heat stability in solar module applications

Abstract

An edge seal for manufacturing two-pane or multi-pane insulating glass or solar modules includes a sealant and a bonding agent. The sealant contains a polymer modified with special reactive groups and has the following overall composition: olefinic polymers included in an amount from about 10% to about 90% by weight of the total composition; at least one filler included in an amount from about 10% to about 65% by weight of the total composition; at least one inorganic filler that is a thermal and oxidative stabilizer in an amount from about 2% to about 30%; at least one of a desiccant and a water scavenger included in an amount from about 2.5% to about 25% by weight of the total composition; and at least one aging resistor including an anti-oxidant or UV stabilizer included in an amount from about 0% to about 3% by weight of the total composition.

1 . An edge seal for manufacturing two-pane or multi-pane insulating glass or solar modules, the edge seal including a sealant and a bonding agent, wherein the sealant contains a polymer modified with special reactive groups and has the following overall composition:
 a) olefinic polymers or combinations thereof included in an amount from about 10% to about 90% by weight of the total composition;   b) at least one filler included in an amount from about 10% to about 65% by weight of the total composition;   c) at least one inorganic filler that is a thermal and oxidative stabilizer in an amount from about 2% to about 30% by weight of the total composition;   d) at least one of a desiccant and water scavenger included in an amount from about 2.5% to about 25% by weight of the total composition; and   e) at least one aging resistor including an anti-oxidant or UV stabilizer included in an amount from about 0.1% to about 3% by weight of the total composition.   
     
     
         2 . The edge seal of  claim 1  wherein the olefinic polymers are included in an amount from about 10% to about 60% by weight of the total composition and a silane modified polymer is included in an amount from about 5% to about 35% by weight of the total composition. 
     
     
         3 . The edge seal of  claim 2  wherein the fillers further include fine particle fillers in an amount from about 5% to about 60% by weight of the total composition. 
     
     
         4 . The edge seal of  claim 2  wherein the olefinic polymers are selected from the group consisting of polyisobutylene, polybutene, butyl rubber (polyisobutylene-isoprene), styrene block copolymers, SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butylene-styrene), SEPS (styrene-ethylene-propylene-styrene), SIBS (styrene-isoprene-butadiene-styrene), SPIBS (styrene-polyisobutylene-styrene), also in modified form, and amorphous copolymers and/or terpolymers of α-olefins (APAO). 
     
     
         5 . The edge seal of  claim 2  wherein the silane modified polymer is selected from the group consisting of polyisobutylene, polybutene, butyl rubber (polyisobutylene-isoprene), styrene block copolymers, SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butylene-styrene), SEPS (styrene-ethylene-propylene-styrene), SIBS (styrene-isoprene-butadiene-styrene), SPIBS (styrene-polyisobutylene-styrene), and amorphous copolymers and/or terpolymers of α-olefins (APAO). 
     
     
         6 . The edge seal of  claim 5  wherein the APAO polymers are modified with at least one group of formula (1) which is a terminal group or is distributed statistically within the chain 
       
         
           
           
               
               
           
         
       
       where -A- is
   —(CH 2 ) m —  (2),
 
   —S—(CH 2 ) m —  (3) or
 
 
       
         
           
           
               
               
           
         
         and R 1  and R 2  are the same or different and are an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, 
         X is a hydroxyl group or a hydrolyzable group, 
         a is 0,1,2 or 3 and b is 0,1 or 2, the sum of a and b being greater than or equal to 1, and where n is a whole number between 0 and 18, m is a whole number between 0 and 4 and R 3  is 
       
       
         
           
           
               
               
           
         
       
     
     
         7 . The edge seal of  claim 3  wherein the fine particle fillers of the sealant are selected from the group comprising ground and precipitated chalks, lime, silicates, silicon oxides and Carbon blacks. 
     
     
         8 . The edge seal of  claim 7  wherein the chalks of the sealant are surface-treated calcium carbonate. 
     
     
         9 . The edge seal of  claim 7  wherein the silicates of the sealant are selected from the group consisting of talc, kaolin, mica, silicon oxides, silicas and calcium or magnesium silicates. 
     
     
         10 . The edge seal of  claim 1  wherein the inorganic filler is carbon black. 
     
     
         11 . The edge seal of  claim 1  wherein the desiccants or water scavengers of the sealant are selected from the group consisting of molecular sieves, phosphorous pentoxide, calcium oxide, anhydrous salt, epoxidized vegetable oil, carbodiimide, p-toluenesulfonyl isocyanate or combinations thereof. 
     
     
         12 . The edge seal of  claim 1  wherein the desiccants or water scavengers of the sealant are selected from molecular sieves (zeolites) of types 3A to 10A. 
     
     
         13 . The edge seal of  claim 1  wherein the aging resistors of the sealant are selected from the group comprising sterically hindered phenols, thioethers, mercapto compounds, phosphorus esters, benzotriazoles, benzophenones, HALS (Hindered Amine Light Stabilizers) and antioxidants. 
     
     
         14 . The edge seal of  claim 2  wherein the olefinic polymers are included in an amount from about 30% to about 50% by weight and have an number average molecular weight from about 5,000 D to about 1,000,000 D, the silane modified polymer is included in an amount from about 5% to about 25% by weight, and the desiccants or water scavengers are included in an amount up to about 15% by weight of the total composition. 
     
     
         15 . A solar module comprising:
 a first substrate;   a second substrate;   at least one photovoltaic cell disposed between the first and second substrates;   a sealant in contact with the first and second substrates to form a moisture vapor barrier to hinder moisture vapor from reaching the at least one photovoltaic cell, wherein the sealant includes:
 an olefinic polymer; 
 at least one of a silane modified APAO and a silane modified polyisobutylene; 
 at least one filler; 
 at least one inorganic filler that is a thermal and oxidative stabilizer; 
 at least one of a water scavenger and a desiccant; and 
 at least one aging resistor, and 
   
       wherein the sealant electrically insulates the photovoltaic cell. 
     
     
         16 . The solar module of  claim 15  wherein at least one of the first and second substrates is at least one of glass, polymeric and metallic. 
     
     
         17 . The solar module of  claim 15  wherein the olefinic polymer includes a polyisobutylene in an amount from about 10% to about 60% by weight of the total composition, the at least one of the silane modified APAO and the silane modified polyisobutylene is included in an amount from about 5% to about 30% by weight of the total composition, the filler is included in an amount from about 10% to about 60% by weight of the total composition, the at least one inorganic filler is a carbon black in the amount from about 2% to about 30%, the at least one of the water scavenger and the desiccant is included in an amount from about 2.5% to about 25% by weight of the total composition, and the aging resistor is included in an amount from 0.1% to about 3% by weight of the total composition. 
     
     
         18 . The solar module of  claim 17  wherein the carbon black is oxidatively post treated by a furnace process and included in an amount from 5 to 30% by weight of the total sealant composition, wherein the sealant composition has a volume resistivity of greater than 1×10 10  ohms·cm. 
     
     
         19 . A compound used in a solar module having a photovoltaic cell, the compound comprising:
 an olefinic polymer;   at least one of a silane modified APAO and a silane modified polyisobutylene;   at least one filler;   at least one inorganic filler that is a thermal and oxidative stabilizer including a carbon black;   at least one of a water scavenger and a desiccant; and   at least one aging resistor, and   wherein the compound electrically insulates the photovoltaic cell.   
     
     
         20 . The compound of  claim 19  wherein the olefinic polymer includes a polyisobutylene in an amount from about 10% to about 60% by weight of the total compound, the at least one of the silane modified APAO and the silane modified polyisobutylene is included in an amount from about 5% to about 30% by weight of the total compound, the filler is included in an amount from about 10% to about 60% by weight of the total compound, the carbon black in the amount from about 2% to about 30%, the at least one of the water scavenger and the desiccant is included in an amount from about 2.5% to about 25% by weight of the total compound, and the aging resistor is included in an amount from 0.1% to about 3% by weight of the total compound. 
     
     
         21 . An edge seal for manufacturing two-pane or multi-pane insulating glass or solar modules, the edge seal including a sealant and a bonding agent, wherein the sealant contains a polymer modified with special reactive groups and has the following overall composition:
 a) olefinic polymers or combinations thereof included in an amount from about 30% to about 90% by weight of the total composition;   b) at least one filler included in an amount from about 10% to about 65% by weight of the total composition;   c) a carbon black wherein the carbon black is included in an amount greater than about 5% by weight of the total composition;   d) at least one of a desiccant and water scavenger included in an amount from about 2.5% to about 25% by weight of the total composition; and   e) at least one aging resistor including an anti-oxidant or UV stabilizer included in an amount from about 0.1% to about 3% by weight of the total composition.   
     
     
         22 . The edge seal of  claim 21  wherein the carbon black is oxidatively post treated by a furnace process and included in an amount from 5 to 20% by weight of the total sealant composition, wherein the sealant composition has a volume resistivity of greater than 1×10 6  ohms·cm. 
     
     
         23 . The edge seal of  claim 21  wherein the bonding agent and the sealant are compatible to produce a seal that is substantially stable to external influences of high temperature and thermal cycling. 
     
     
         24 . A sealing compound for use in a solar module having a first substrate and a second substrate, wherein the sealing compound is disposed between the first substrate and the second substrate, the sealing compound comprising:
 an olefinic polymer in an amount greater than about 30% by weight of the total compound;   at least one of a silane modified APAO and a silane modified polymer in an amount less than 35% by weight of the total compound;   a filler;   a carbon black wherein the carbon black is included in an amount greater than about 5% by weight of the total compound;   at least one of a water scavenger and a desiccant; and   an aging resistor.   
     
     
         25 . The sealing compound of  claim 24  wherein the carbon black is oxidatively post treated by a furnace process and included in an amount from 5 to 20% by weight of the total compound, wherein the sealing compound has a volume resistivity of greater than 1×10 6  ohms·cm. 
     
     
         26 . The sealing compound of  claim 24  wherein the sealing compound is oxidatively stable after 4000 hrs of exposure to temperatures greater than 110° C. 
     
     
         27 . The sealing compound of  claim 24  wherein the sealing compound produces a seal that is substantially stable to external influences of high temperature and thermal cycling. 
     
     
         28 . A sealing compound for use in a solar module having a first substrate and a second substrate, wherein the sealing compound is disposed between the first substrate and the second substrate, the sealing compound comprising:
 an olefinic polymer;   at least one of a silane modified APAO and a silane modified;   a filler;   a carbon black as a thermal and oxidative stabilizer;   at least one of a water scavenger and a desiccant; and   an aging resistor, and   wherein the sealing compound has a relative thermal index of at least about 105° C.