Method of Bonding Perfluoroelastomeric Materials to a Surface

Abstract

The invention includes a method of bonding a perfluoroelastomer material to first surface that includes: (a) contacting a first surface with a bonding agent comprising a curable perfluoropolymer and a curing agent; (b) curing the bonding agent to form a perfluoroelastomer material that is bonded to the first surface. In the practice of such method, the bonding agent may be a solution prepared by dissolving the curable perfluoroelastomer and the curing agent in a solvent. In an embodiment of the invention, the perfluoroelastomer material formed in step (b) is a coating layer or, alternatively, the first surface is a surface of a perfluoroelastomer member and the perfluoroelastomer material formed is a perfluoroelastomer weld.

1 . A method of bonding a perfluoroelastomer material to first surface comprising:
 (a) contacting a first surface with a bonding agent comprising a curable perfluoropolymer and a curing agent; and   (b) curing the bonding agent to form a perfluoroelastomer material that is bonded to the first surface.   
     
     
         2 . The method of  claim 1 , wherein the bonding agent is a solution prepared by dissolving the curable perfluoroelastomer and the curing agent in a solvent. 
     
     
         3 . The method of  claim 2 , wherein the solvent is a fluorinated solvent. 
     
     
         4 . The method of  claim 2 , wherein the perfluoroelastomer material formed in step (b) is a coating layer. 
     
     
         5 . The method of  claim 2  wherein the bonding agent is prepared by a method comprising:
 (i) forming a first solution of the curable perfluoropolymer and a first solvent;   (ii) forming a second solution of the curing agent and a second solvent; and   (iii) combining the first solution and the second solution.   
     
     
         6 . The method of  claim 5 , wherein the first solvent and the second solvent are identical. 
     
     
         7 . The method of  claim 1 , wherein the curing step (b) further comprises heating for a time period sufficient to effectively cure the perfluoroelastomer material. 
     
     
         8 . The method of  claim 1 , wherein the curing step further comprises heating to about 149° C. (300° F.). 
     
     
         9 . The method of  claim 1 , wherein step (a) comprises spraying the bonding agent onto the surface. 
     
     
         10 . The method of  claim 1 , wherein the curable perfluoropolymer has at least one curesite monomer comprising a cyano group. 
     
     
         11 . The method according to  claim 1 , wherein the curing agent is selected from the group consisting of a monoamidine, a monoamidoxime, an aryldioxime, perfluorooctamidine, heptafluorobutyrlamidine, a bisphenol or a derivative thereof, a tetraphenyltin, a triazine, and a peroxide-based curing system. 
     
     
         12 . The method of  claim 1 , wherein the first surface is a surface of a perfluoroelastomer member and the perfluoroelastomer formed is a perfluoroelastomer weld. 
     
     
         13 . The method of  claim 12 , wherein step (a) further comprises contacting the bonding agent to a second surface and step (c) further comprises curing the bonding agent to form a perfluoroelastomer weld between the first surface and the second surface, wherein upon curing the perfluoroelastomer weld comprises essentially the same perfluoroelastomer as the perfluoroelastomer member. 
     
     
         14 . The method of  claim 13 , further comprising post-curing the perfluoroelastomer weld. 
     
     
         15 . The method of  claim 14 , wherein the perfluoroelastomer weld is about 95% cured. 
     
     
         16 . The method of  claim 14 , wherein the perfluoroelastomer member and the weld form a part and the method further comprises post-curing the part. 
     
     
         17 . The method of  claim 13 , wherein the bonding agent is produced by the steps comprising:
 compounding a perfluoroelastomer formulation to form a compound; and   dissolving the compound in a solvent to form a solution, wherein the bonding agent is contacted with the first surface by coating the first surface with the bonding agent.   
     
     
         18 . A method of forming a perfluoroelastomer coating comprising (a) dissolving a curable perfluoropolymer and a curing agent in a solvent to form a solution, (b) applying the solution to a surface; and (c) curing the perfluoropolymer to form a cured perfluoroelastomeric coating on the surface. 
     
     
         19 . The method according to  claim 18 , wherein step (c) comprises heating the coating layer for a sufficient period of time to effectively cure the perfluoropolymer. 
     
     
         20 . The method according to  claim 18 , wherein the curing step further comprises heating the coating layer to about 149° C. (300° F.). 
     
     
         21 . The method according to  claim 18 , wherein step (a) further comprises
 (i) forming a first solution of the curable perfluoropolymer and a first solvent;   (ii) forming a second solution of the curing agent and a second solvent; and   (iii) combining the first solution and the second solution.   
     
     
         22 . The method according to  claim 21 , wherein the first solvent and the second solvent are identical. 
     
     
         23 . The method according to  claim 18 , wherein step (b) comprises spraying the solution onto the surface. 
     
     
         24 . The method according to  claim 18 , wherein the curable perfluoropolymer has at least one curesite monomer comprising a cyano group. 
     
     
         25 . The method according to  claim 18 , wherein the curing agent is selected from the group consisting of a monoamidine, a monoamidoxime and an aryldioxime. 
     
     
         26 . The method according to  claim 25 , wherein the curing agent is perfluorooctanaidine or heptafluorobutyrlamidine. 
     
     
         27 . The method according to  claim 18 , wherein the solution comprises about 1% to about 25% by weight of the perfluoropolymer based on the total weight of the solution. 
     
     
         28 . The method according to  claim 27 , wherein the solution comprises about 1% to about 10% by weight of the perfluoropolymer based on the total weight of the solution. 
     
     
         29 . The method according to  claim 28 , wherein the solution comprises about 1% to about 5% by weight of the perfluoropolymer based on the total weight of the solution. 
     
     
         30 . The method according to  claim 29 , wherein the solution comprises about 0.01% to about 5% by weight of the curing agent, based on the total weight of the solution. 
     
     
         31 . The method according to  claim 30 , wherein the solution comprises about 0.01% to about 1.5% by weight of the curing agent based on the total weight of the solution. 
     
     
         32 . The method according to  claim 31 , wherein the solution comprises about 0.25% to about 1% by weight of the curing agent based upon total weight of the solution. 
     
     
         33 . A coated substrate comprising a cured perfluoroelastomer coating applied on at least one surface of the substrate. 
     
     
         34 . The coated substrate according to  claim 33 , wherein the perfluoroelastomer coating is formed by a curing reaction of a curable perfluoropolymer and a curing agent in a solution applied to the surface of the substrate. 
     
     
         35 . The coated substrate according to  claim 34 , wherein the curable perfluoropolymer has at least one curesite monomer having a cyano group and the curing agent is a monoamidine, monoamidoxime or aryldioxime. 
     
     
         36 . The coated substrate according to  claim 35 , wherein the curing agent is perfluorooctanamidine or heptafluorobutyrlamidine. 
     
     
         37 . A method of bonding a perfluoroelastomer member to a surface, comprising:
 (a) contacting a first surface of a perfluoroelastomer member with a bonding agent comprising:
 a curable perfluoropolymer, and 
 a curing agent; 
   (b) placing the bonding agent also in contact with a second surface; and   (c) curing the bonding agent to form a perfluoroelastomer weld between the first and second surface, wherein upon curing the perfluoroelastomer weld comprises essentially the same perfluoroelastomer as the perfluoroelastomer member.   
     
     
         38 . The method of  claim 37 , further comprising post-curing the perfluoroelastomer weld. 
     
     
         39 . The method of  claim 38 , wherein the perfluoroelastomer weld is about 95% cured. 
     
     
         40 . The method of  claim 38 , wherein the perfluoroelastomer member and the weld form a part and the method further comprises post-curing the part. 
     
     
         41 . The method of  claim 40 , wherein the part is a seal. 
     
     
         42 . The method of  claim 40 , wherein the part is homogeneous. 
     
     
         43 . The method of  claim 38 , wherein the perfluoroelastomer weld is homogeneous with the perfluoroelastomer member. 
     
     
         44 . The method of  claim 38 , wherein the first and second surfaces are on the same perfluoroelastomer member. 
     
     
         45 . The method of  claim 38 , wherein in step (a) the perfluoroelastomer member is about 75% to about 95% cured. 
     
     
         46 . The method of  claim 37 , wherein step (b) further comprises:
 placing the first surface and the second surface within a fixture; and   positioning the first surface, the bonding agent and the second surface within the fixture, such that the first surface, the bonding agent and the second surface are in contact.   
     
     
         47 . The method of  claim 37 , wherein step (c) further comprises heating the bonding agent for a sufficient period of time to effectively cure the bonding agent. 
     
     
         48 . The method of  claim 37 , wherein step (c) further comprises heating the perfluoroelastomer bonding agent to about 149° C. (300° F.). 
     
     
         49 . The method of  claim 37 , wherein the bonding agent further comprises a solvent and the bonding agent is contacted with the first surface by coating the first surface with the bonding agent. 
     
     
         50 . The method of  claim 49 , wherein the solvent is a fluorinated solvent. 
     
     
         51 . The method of  claim 37 , wherein the curing agent is at least one of a bisphenol or a derivative thereof, a tetraphenyltin, a triazine, and a peroxide-based curing system. 
     
     
         52 . The method of  claim 37 , wherein the bonding agent is produced by the steps comprising:
 compounding a perfluoroelastomer formulation to form a compound; and   dissolving the compound in a solvent to form a solution, wherein the bonding agent is contacted with the first surface by coating the first surface with the bonding agent and the bonding agent is contacted with the first surface by coating the first surface with the bonding agent.   
     
     
         53 . The method of  claim 52 , wherein the step of dissolving comprises:
 forming the compound into pieces;   adding about 70% to about 95% by weight solvent to the pieces of the compound, and   dispersing the particulates of the pieces while dissolving the pieces on a ball mill.   
     
     
         54 . The method of  claim 52 , wherein the solvent is added in an amount of about 90% to about 95% by weight of the solution. 
     
     
         55 . A method of bonding a perfluoroelastomer seal to a gland, comprising:
 placing a bonding agent comprising a curable perfluoropolymer and curing agent within gaps formed between a perfluoroelastomer seal and a gland; and   curing the bonding agent; wherein upon curing, the perfluoropolymer forms essentially the same perfluoroelastomer as the perfluoroelastomer seal.