Bisaminophenyl-based curatives and amidine-based curatives and cure accelerators for perfluoroelastomeric compositions

Abstract

Novel monoamidine, monoamidoxime and bisamidine curatives, co-curatives and cure accelerators are provided for use with perfluoroelastomeric compositions as well as novel synthesis methods for making monoamidine- and monoamidoxime-based curatives, co-curatives and cure accelerators. Also provided are diphenyl-based curatives, co-curatives and cure accelerators having sufficiently high molecular weight such that the melting temperature of the curatives, co-curatives and cure accelerators is no greater than about 240° C., and more preferably no greater than about 230° C.

We claim:  
     
         1 . A curative for perfluoroelastomeric compositions having formula (I):  
       
         
           
           
               
               
           
         
       
       wherein Y is selected from the group consisting of substituted alkyl, alkoxy, aryl, aralkyl or aralkoxy groups of from 1 to about 22 carbon atoms; substituted or unsubstituted halogenated alkyl, alkoxy, aryl, aralkyl or aralkoxy groups of from about 1 to about 22 carbon atoms, and perfluoroalkyl, perfluoroalkoxy, perfluoroaryl, perfluoroaralkyl or perfluoroaralkoxy groups of from 1 to about 22 carbon atoms; and R 1  is hydrogen; substituted or unsubstituted lower alkyl or alkoxy groups of from 1 to about 6 carbon atoms; and an amino group; and R 2  is R 1  or hydroxyl.  
     
     
         2 . The curative according to  claim 1 , wherein Y is a perfluorinated alkyl group having about 1 to about 9 carbon atoms.  
     
     
         3 . The curative according to  claim 1 , wherein Y is selected from the group consisting of perfluoroalkyl, perfluoroalkoxy, substituted and unsubstituted aryl groups and substituted and unsubstituted halogenated aryl groups.  
     
     
         4 . The curative according to  claim 1 , wherein the curative is selected from the group consisting of perfluorooctanamidine, heptafluorobutyrylamidine, benzamidine, trifluoromethylbenzamidoxime, trifluoromethoxylbenzamidoxime, and combinations thereof.  
     
     
         5 . The curative according to  claim 1 , wherein the curative is capable of curing perfluoroelastomeric compositions comprising at least one cyano curesite monomer.  
     
     
         6 . The curative according to  claim 1 , wherein R 2  is hydroxyl, hydrogen or a substituted or unsubstituted alkyl group of from 1 to about 6 carbon atoms.  
     
     
         7 . The curative according to  claim 6 , wherein R 2  is hydroxyl or hydrogen.  
     
     
         8 . The curative according to  claim 1 , wherein R 1  is hydrogen or a substituted or unsubstituted lower alkyl group of from 1 to about 6 carbon atoms and R 2  is hydroxyl or hydrogen.  
     
     
         9 . The curative according to  claim 8 , wherein R 1  is hydrogen.  
     
     
         10 . The curative according to  claim 1 , wherein the curative is a perfluoroalkylamidine.  
     
     
         11 . The curative according to  claim 1 , wherein the curative is an arylamidine.  
     
     
         12 . The curative according to  claim 1 , wherein the curative is an arylamidoxime.  
     
     
         13 . A cure accelerator for perfluoroelastomeric compositions having formula (I):  
       
         
           
           
               
               
           
         
       
       wherein Y is selected from the group consisting of substituted alkyl, alkoxy, aryl, aralkyl or aralkoxy groups of from 1 to about 22 carbon atoms; substituted or unsubstituted halogenated alkyl, alkoxy, aryl, aralkyl or aralkoxy groups of from about 1 to about 22 carbon atoms, and perfluoroalkyl, perfluoroalkoxy, perfluoroaryl, perfluoroaralkyl or perfluoroaralkoxy groups of from 1 to about 22 carbon atoms; and R 1  is hydrogen; substituted or unsubstituted lower alkyl or alkoxy groups of from 1 to about 6 carbon atoms; and an amino group; and R 2  is R 1  or hydroxyl.  
     
     
         14 . The cure accelerator according to  claim 13 , wherein Y is a perfluorinated alkyl group having about 1 to about 9 carbon atoms.  
     
     
         15 . The cure accelerator according to  claim 13 , wherein the cure accelerator is selected from the group consisting of perfluorooctanamidine, heptafluorobutyrylamidine, benzamidine, trifluoromethylbenzamidoxime, trifluoromethoxylbenzamidoxime, and combinations thereof.  
     
     
         16 . The monoamidine-based cure accelerator according to  claim 13 , wherein the cure accelerator is capable of accelerating the cure of perfluoroelastomeric compositions comprising at least one cyano curesite monomer.  
     
     
         17 . The monoamidine-based cure accelerator according to  claim 13 , wherein the cure accelerator is capable of accelerating the cure of perfluoroelastomeric compositions comprising bisaminophenol and its derivatives.  
     
     
         18 . A bisamidine-based cure accelerator for perfluoroelastomeric compositions as represented by formula (II):  
       
         
           
           
               
               
           
         
       
       wherein D is selected from the group consisting of unsubstituted or substituted halogenated alkyl, alkoxy, aryl, aralkyl or aralkoxy groups having from about 1 to about 22 carbon atoms; and perfluoroalkyl, perfluoroalkoxy, perfluoroaryl, perfluoroaralkyl or perfluoroalkoxy groups of from 1 to about 22 carbon atoms; and R 1  and R 2  are each independently selected to be hydrogen; substituted or unsubstituted lower alkyl or alkoxy groups of from 1 to about 6 carbon atoms and an amino group.  
     
     
         19 . The bisamidine-based cure accelerator according to  claim 18 , wherein R 1  and R 2  are both hydrogen.  
     
     
         20 . The bisamidine-based cure accelerator according to  claim 18 , wherein the cure accelerator is capable of accelerating the cure of perfluoroelastomers comprising at least one cyano curesite monomer.  
     
     
         21 . The bisamidine-based cure accelerator according to  claim 18 , wherein the cure accelerator is selected from the group consisting of perfluorosuberamidine and perfluorosebacamidine.  
     
     
         22 . A curable perfluoroelastomeric composition, comprising: 
 (a) a perfluoropolymer having at least one curesite monomer comprising a cyano functional group;    (b) at least one monoamidine-based or monoamidoxime-based curative.    
     
     
         23 . The curable perfluoroelastomeric composition according to  claim 22 , wherein the perfluoropolymer is a tetrapolymer of tetrafluoroethylene, perfluoroalkylvinylether, a primary cyano curesite monomer and a secondary cyano curesite monomer.  
     
     
         24 . The curable perfluoroelastomeric composition according to  claim 22 , further comprising a bisamidine-based cure accelerator.  
     
     
         25 . The curable curable perfluoroelastomeric composition according to  claim 22 , further comprising bisaminophenol and its derivatives.  
     
     
         26 . A curable perfluoroelastomeric composition, comprising: 
 (a) a perfluoropolymer having at least one curesite monomer comprising a cyano functional group;    (b) a functionalized diphenyl-based curative; and    (c) a cure accelerator selected from the group consisting of at least one monoamidine-based cure accelerator, at least one monoamidoxime-based cure accelerator, at least one bisamidine-based cure accelerator and combinations thereof.    
     
     
         27 . The curable perfluoroelastomeric composition according to  claim 26 , wherein wherein the perfluoropolymer is a perfluoropolymer that is a tetrapolymer of tetrafluoroethylene, perfluoroalkylvinylether, a primary cyano curesite monomer and a secondary cyano curesite monomer.  
     
     
         28 . The curable perfluoroelastomeric composition according to  claim 26 , wherein the diphenyl-based curative has a sufficiently high molecular weight so that the melting point is no greater than about 240° C.  
     
     
         29 . The curable perfluoroelastomeric composition according co  claim 28 , wherein the melting point is no greater than about 230° C.  
     
     
         30 . The curable perfluoroelastomeric composition according to  claim 29 , wherein the melting point is no greater than about 225° C.  
     
     
         31 . The curable perfluoroelastomeric composition according to  claim 26 , wherein the functionalized diphenyl-based curative has formula (III):  
       
         
           
           
               
               
           
         
       
       wherein r is 0 or 1; 
 R 3  and R 4  are each independently selected from the group consisting of a carbon atom; substituted and unsubstituted and branched and straight chain carbon groups of from about 2 to about 22 carbon atoms selected from the group consisting of alkyl groups, halogenated alkyl groups, and perfluorinated alkyl groups, each of which groups may be interrupted by at least one oxygen atom;  
 each Z is independently selected from the group consisting of an amino, mercapto, sulfhydryl, or hydroxyl group;  
 each J is independently selected to be formula (IV):  
                     
 or A; and  
 each A is independently selected from the group consisting of formula (IV); a fluorine atom; and unsubstituted and substituted and branched and straight chain carbon-based groups which are selected from group consisting of alkyl, halogenated alkyl, and perfluoroalkyl groups of from 1 to about 22 carbon atoms; each of which groups may be interrupted by at least one oxygen atom; wherein when r is 0 and R 3  is a carbon atom, at least one of J and each A is not formula (IV).  
 
     
     
         32 . The curable perfluoroelastomeric composition according to  claim 31 , wherein the diphenyl-based formula has formula III wherein r is 0, R 3  is a carbon atom, J is formula IV, one A is trifluoromethyl and the other A is selected from the group consisting of linear and branched chain perfluoroalkyl and perfluoroalkylether groups of from 2 to 22 carbon atoms.  
     
     
         33 . The curable perfluoroelastomeric composition according to  claim 31 , wherein r is 1, each A and each J are a fluorine atom, R 3  is a carbon atom and R 4  is selected from the group consisting of linear and branched chain perfluoroalkylene and perfluoroalkylether groups of from 2 to 22 carbon atoms, and wherein one A and one J are both bonded to the terminal carbon atom of R 4 .  
     
     
         34 . The curable perfluorelastomeric composition according to  claim 32 , wherein the Z-substituted aminophenyl group on R 4  is also bonded to the terminal carbon of R 4  which has the A and the J.  
     
     
         35 . A curative for a perfluoroelastomeric composition, the curative having formula (III):  
       
         
           
           
               
               
           
         
       
       wherein r is 0 or 1; 
 R 3  and R 4  are each independently selected from the group consisting of a carbon atom; substituted and unsubstituted and branched and straight chain carbon groups of from about 2 to about 22 carbon atoms selected from the group consisting of alkyl groups, halogenated alkyl groups, and perfluorinated alkyl groups, each of which groups may be interrupted by at least one oxygen atom;  
 each Z is independently selected from the group consisting of an amino, mercapto, sulfhydryl, or hydroxyl group;  
 each J is independently selected to be formula (IV):  
                     
 or A; and  
 each A is independently selected from the group consisting of formula (IV); a fluorine atom; and unsubstituted and substituted and branched and straight chain carbon-based groups which are selected from group consisting of alkyl, halogenated alkyl, and perfluoroalkyl groups of from 1 to about 22 carbon atoms; each of which groups may be interrupted by at least one oxygen atom; wherein when r is 0 and R 3  is a carbon atom, at least one of J and each A is not formula (IV).  
 
     
     
         36 . A curative for a perfluoroelastomeric composition, comprising a functionalized diphenyl-based curative which has a sufficiently high molecular weight so that the melting point is no greater than about 240° C.  
     
     
         37 . The curative according to  claim 36 , wherein the melting point is no greater than about 230° C.  
     
     
         38 . The curative according to  claim 37 , wherein the melting point is no greater than about 225° C.  
     
     
         39 . The curative according to  claim 36 , wherein the perfluoroelastomeric composition comprises a perfluoropolymer having at least one cyano group containing curesite monomer.  
     
     
         40 . A method for using a compound having formula (I):  
       
         
           
           
               
               
           
         
       
       wherein Y is selected from the group consisting of substituted alkyl, alkoxy, aryl, aralkyl or aralkoxy groups of from 1 to about 22 carbon atoms; substituted or unsubstituted halogenated alkyl, alkoxy, aryl, aralkyl or aralkoxy groups of from about 1 to about 22 carbon atoms, and perfluoroalkyl, perfluoroalkoxy, perfluoroaryl, perfluoroaralkyl or perfluoroaralkoxy groups of from 1 to about 22 carbon atoms; and R 1  is hydrogen; substituted or unsubstituted lower alkyl or alkoxy groups of from 1 to about 6 carbon atoms; and an amino group; and R 2  is R 1  or hydroxyl, wherein the compound is used as a curative for a perfluoroelastomeric composition.  
     
     
         41 . The method according to  claim 40 , wherein the perfluoroelastomeric composition comprises a perfluoropolymer having at least one cyano-group containing curesite monomer.  
     
     
         42 . A method for curing a perfluoroelastomeric composition comprising using a mixture of (i) at least one compound selected from the group consisting of monoamidine-based compounds, monoamidoxime-based compounds, and mixtures thereof and (ii) at least one bisamidine-based compound as co-curatives for the perfluoroelastomeric composition.  
     
     
         43 . A method for accelerating curing of a perfluoroelastomeric composition, comprising using a cure accelerator for a curative, wherein the cure accelerator is selected from the group consisting of a monoamidine-based compound, a monoamidoxime-based compound, a bisamidine-based compound and combinations thereof.  
     
     
         44 . A method for curing a perfluoroelastomeric composition comprising using a functionalized diphenyl-based curative having a sufficiently high molecular weight such that the melting point is no greater than about 240° C as a curative for the perfluoroelastomeric composition.  
     
     
         45 . The method according to  claim 44 , wherein the melting point is no greater than about 230° C.