Peroxide-curable fluoropolymer composition including solvent and method of using the same

Abstract

A curable composition that includes an amorphous, peroxide-curable fluoropolymer having a first solubility parameter, a solvent having a second solubility parameter, and a peroxide. The amorphous, peroxide-curable fluoropolymer is present from 60 percent to 97.5 percent by weight versus the weight of the curable composition, and the solvent is present from 1 percent to 39 percent by weight versus the weight of the curable composition. The absolute value of the first solubility parameter minus the second solubility parameter is less than or equal to 8.2 (MPa) 1/2 . The solvent may have a solubility parameter in a range from 9.6 (MPa) 1/2 to 26 (MPa) 1/2 . Methods of making a cured fluoroelastomer from the curable composition are also disclosed.

1 . A curable composition comprising:
 an amorphous, peroxide-curable fluoropolymer having a first solubility parameter, wherein the amorphous, peroxide-curable fluoropolymer is present from 60 percent to 97.5 percent by weight versus the weight of the curable composition,   a solvent having a second solubility parameter, wherein the solvent is present from 1 percent to 39 percent by weight versus the weight of the curable composition, and   a peroxide,   
       wherein the absolute value of the first solubility parameter minus the second solubility parameter is less than or equal to 8.2 (MPa) 1/2 . 
     
     
         2 . The curable composition of  claim 1 , wherein the absolute value of the first solubility parameter minus the second solubility parameter is less than or equal to 4.1 (MPa) 1/2 . 
     
     
         3 . The curable composition of  claim 1 , wherein the amorphous peroxide-curable fluoropolymer is not present at 80 percent by weight versus the weight of the curable composition. 
     
     
         4 . The curable composition of  claim 1 , wherein the amorphous peroxide-curable fluoropolymer is present in a range from 60 percent by weight to less than 80 percent by weight versus the weight of the curable composition. 
     
     
         5 . The curable composition of  claim 1 , wherein the amorphous peroxide-curable fluoropolymer is present in a range from greater than 80 percent by weight to 97.5 percent by weight versus the weight of the curable composition. 
     
     
         6 . The curable composition of  claim 1 , further comprising a crosslinker. 
     
     
         7 . The curable composition of  claim 6 , wherein the crosslinker is tri(methyl)allyl isocyanurate, triallyl isocyanurate, tri(methyl)allyl cyanurate, poly-triallyl isocyanurate, xylylene-bis(diallyl isocyanurate), N,N′-m-phenylene bismaleimide, diallyl phthalate, tris(diallylamine)-s-triazine, triallyl phosphite, 1,2-polybutadiene, ethyleneglycol diacrylate, diethyleneglycol diacrylate, or CH 2 ═CH—R f1 —CH═CH 2  wherein R f1  is a perfluoroalkylene having from 1 to 8 carbon atoms. 
     
     
         8 . The curable composition of  claim 1 , wherein the amorphous, peroxide-curable fluoropolymer comprises a bromo- or iodo-cure site. 
     
     
         9 . The curable composition of  claim 1 , wherein the curable composition has a viscosity at 25° C. in a range from 100 poise to 24,000 poise. 
     
     
         10 . The curable composition of  claim 1 , wherein the peroxide is an acyl peroxide. 
     
     
         11 . The curable composition of  claim 1 , wherein the solvent has a boiling point in a range from 30° C. to 200° C. 
     
     
         12 . The curable composition of  claim 1 , having at least one of a delta torque at 130° C. for 12 minutes greater than 0.5 dNm as measured by a sealed torsion shear rotorless curemeter in accordance with ASTM D 5289-07 or a tan delta after 12 minutes at 130° C. of less than 0.3 as measured by a sealed torsion shear rotorless curemeter in accordance with ASTM D 5289-07. 
     
     
         13 . The curable composition of  claim 1 , wherein the solvent comprises at least one of acetone, 2-butanone, 4-methyl-2-pentanone, cyclohexanone, methyl formate, ethyl formate, methyl acetate, ethyl acetate, n-butyl acetate, tert-butyl acetate, or dimethyl carbonate. 
     
     
         14 . A method of making a cured fluoroelastomer, the method comprising:
 providing the curable composition of  claim 1 , and   heating the curable composition at a cure temperature to make the cured fluoroelastomer.   
     
     
         15 . The method of  claim 14 , wherein the method does not include first removing the solvent before heating the curable composition. 
     
     
         16 . The method of  claim 14 , wherein the cured fluoroelastomer has an average light transmission in a range from 360 nanometers to 1100 nanometers of at least 70 percent. 
     
     
         17 . A curable composition comprising:
 an amorphous, peroxide-curable fluoropolymer, wherein the amorphous, peroxide-curable fluoropolymer is present from 60 percent to 97.5 percent by weight versus the weight of the curable composition,   a solvent having a solubility parameter in a range from 9.6 (MPa) 1/2  to 26 (MPa) 1/2 , wherein the solvent is present from 1 percent to 39 percent by weight versus the weight of the curable composition, and   a peroxide.   
     
     
         18 . The curable composition of  claim 17 , wherein the solubility parameter of the solvent is in a range from 13.7 (MPa) 1/2  to 21.9 (MPa) 1/2 . 
     
     
         19 . The curable composition of  claim 17 , wherein the amorphous peroxide-curable fluoropolymer is present in a range from 60 percent by weight to less than 80 percent by weight versus the weight of the curable composition. 
     
     
         20 . The curable composition of  claim 17 , wherein the amorphous peroxide-curable fluoropolymer is present in a range from greater than 80 percent by weight to 97.5 percent by weight versus the weight of the curable composition.