Thermoset adhesive films

Abstract

This invention is a film adhesive prepared from an adhesive composition comprising a polymer system, a film forming rubber compound, and curing agents for the polymeric system. The polymer system comprises a base polymer and electron donor and electron acceptor functionality.

1 . A film adhesive prepared from materials comprising 
 (i) a rubbery polymer prepared from acrylic, vinyl, or conjugated diene monomers, containing no electron donor or acceptor functionality, and having a weight average molecular weight in the range of 300,000 to 1,500,000;    (ii) an independent electron donor compound selected from the group consisting of vinyl ethers and compounds containing a carbon to carbon double bond attached to an aromatic ring and conjugated with the unsaturation in the ring;    (iii) an independent electron acceptor compound; and    (iv) a free radical initiator;    characterized in that the film adhesive can be cured within two minutes at a temperature below 300° C.    
     
     
         2 . The film adhesive according to  claim 1  in which the rubbery polymer (i) is an acrylic polymer, a styrene-acrylic copolymer, or a acrylonitrile-butadiene copolymer.  
     
     
         3 . The film adhesive according to  claim 1  in which the independent electron donor compound (ii) is a vinyl ether selected from the group consisting of bis[4-(vinyloxy)butyl]terephthalate, bis[4(vinyloxy)butyl] (4-methyl-1,3-phenylene)-biscarbamate, bis[4-(vinyloxy) butyl] 1,6-hexanediylbiscarbamate, 4-(vinyloxy)-butyl stearate, and bis[4-(vinyloxy) butyl] (methylenedi-4,1-phenylene)-biscarbamate.  
     
     
         4 . The film adhesive according to  claim 1  in which the independent electron donor compound (ii) is a compound containing a carbon to carbon double bond attached to an aromatic ring and conjugated with the unsaturation in the ring and are selected from the group consisting of:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         5 . The film adhesive according to  claim 1  in which the independent electron acceptor compound (iii) is selected from the group consisting of fumarates, maleates, acrylates, and maleimides.  
     
     
         6 . The film adhesive according to  claim 5  in which the independent electron acceptor compound (iii) is a bismaleimide selected from the group consisting of N,N′-ethylene-bis-maleimide, N,N′-butylene-bis-maleimide, N,N′-phenylene-bis-maleimide, N,N′-hexamethylene-bis-maleimide, N,N′-4,4′-diphenyl methane-bis-maleimide, N,N′-4,4′-diphenyl ether-bis-maleimide, N,N′-4,4′-diphenyl sulfone-bis-maleimide, N,N′-4,4′-dicyclohexyl methane-bis-maleimide, N,N′-xylylene-bis-maleimide, and N,N′-diphenyl cyclohexane-bis-maleimide.  
     
     
         7 . A film adhesive prepared from 
 (i) a rubbery polymer prepared from acrylic, vinyl, or conjugated diene monomers, substituted with pendant electron acceptor functionality, and having a weight average molecular weight in the range of 300,000 to 1,500,000,    (ii) an independent electron donor compound selected from the group consisting of vinyl ethers and compounds containing a carbon to carbon double bond attached to an aromatic ring and conjugated with the unsaturation in the ring;    (iii) optionally, an independent electron acceptor compound;    (iv) a free radical initiator;    characterized in that the film adhesive can be cured within two minutes at a temperature below 300° C.    
     
     
         8 . The film adhesive according to  claim 7  in which the rubbery polymer (i) is an acrylic, styrene-acrylic copolymer, or a acrylonitrile-butadiene copolymer.  
     
     
         9 . The film adhesive according to  claim 7  in which the independent electron donor compound (ii) is a vinyl ether selected from the group consisting of bis[4-(vinyloxy)butyl]terephthalate, bis[4(vinyloxy)butyl] (4-methyl-1,3-phenylene)-biscarbamate, bis[4-(vinyloxy) butyl] 1,6-hexanediylbiscarbamate, 4-(vinyloxy)-butyl stearate, and bis[4-(vinyloxy) butyl] (methylenedi-4,1-phenylene)-biscarbamate.  
     
     
         10 . The film adhesive according to  claim 7  in which the independent electron donor compound (ii) is a compound containing a carbon to carbon double bond attached to an aromatic ring and conjugated with the unsaturation in the ring and are selected from the group consisting of:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         11 . The film adhesive according to  claim 7  in which the independent electron acceptor compound (iii) is selected from the group consisting of fumarates, maleates, acrylates, and maleimides.  
     
     
         12 . The film adhesive according to  claim 7  in which the independent electron acceptor compound (iii) is a bismaleimide selected from the group consisting of N,N′-ethylene-bis-maleimide, N,N′-butylene-bis-maleimide, N,N′-phenylene-bis-maleimide, N,N′-4,4′-diphenyl ether-bis-maleimide, N,N′-4,4′-diphenyl sulfone-bis-maleimide, N,N′-4,4′-dicyclohexyl methane-bis-maleimide, N,N′-xylylene-bis-maleimide, and N,N′-diphenyl cyclohexane-bis-maleimide.  
     
     
         13 . A film adhesive prepared from 
 (i) a rubbery polymer prepared from acrylic, vinyl, or conjugated diene monomers, substituted with pendant electron donor functionality, and having a weight average molecular weight in the range of 300,000 to 1,500,000,    (ii) an independent electron acceptor compound;    (iii) optionally, an independent electron donor compound selected from the group consisting of vinyl ethers and compounds containing a carbon to carbon double bond attached to an aromatic ring and conjugated with the unsaturation in the ring; and    (iv) a free radical initiator;    characterized in that the film adhesive can be cured within two minutes at a temperature below 300° C.    
     
     
         14 . The film adhesive according to  claim 13  in which the rubbery polymer (i) is an acrylic, styrene-acrylic copolymer, or a acrylonitrile-butadiene copolymer.  
     
     
         15 . The film adhesive according to  claim 15  in which the independent electron acceptor compound (ii) is selected from the group consisting of fumarates, maleates, acrylates, and maleimides.  
     
     
         16 . The film adhesive according to  claim 13  in which the independent electron acceptor compound (ii) is a bismaleimide selected from the group consisting of N,N′-ethylene-bis-maleimide, N,N′-butylene-bis-maleimide, N,N′-phenylene-bis-maleimide, N,N′-hexamethylene-bis-maleimide, N,N′-4,4′-diphenyl methane-bis-maleimide, N,N′-4,4′-diphenyl ether-bis-maleimide, N,N′-4,4′-diphenyl sulfone-bis-maleimide, N,N′4,4′-dicyclohexyl methane-bis-maleimide, N,N′-xylylene-bis-maleimide, and N,N′-diphenyl cyclohexane-bis-maleimide.  
     
     
         17 . The film adhesive according to  claim 13  in which the independent electron donor compound (iii) is a vinyl ether selected from the group consisting of bis[4-(vinyloxy)butyl]terephthalate, bis[4(vinyloxy)butyl] (4-methyl-1,3-phenylene)-biscarbamate, bis[4-(vinyloxy) butyl] 1,6-hexanediylbiscarbamate, 4-(vinyloxy)-butyl stearate, and bis[4-(vinyloxy) butyl] (methylenedi-4,1-phenylene)-biscarbamate.  
     
     
         18 . The film adhesive according to  claim 13  in which the independent electron donor compound (iii) is a compound containing a carbon to carbon double bond attached to an aromatic ring and conjugated with the unsaturation in the ring and are selected from the group consisting of:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         19 . A rubbery film adhesive prepared from 
 (i) a rubbery polymer prepared from acrylic, vinyl, or conjugated diene monomers, substituted with pendant electron donor and pendant electron acceptor functionality, and having a weight average molecular weight in the range of 300,000 to 1,500,000, or    (ii) a combination of (a) a rubbery polymer prepared from acrylic, vinyl, or conjugated diene monomers, substituted with pendant electron donor functionality and having a weight average molecular weight in the range of 300,000 to 1,500,000, and (b) a rubbery polymer prepared from acrylic, vinyl, or conjugated diene monomers, substituted with pendant electron acceptor functionality and having a weight average molecular weight in the range of 300,000 to 1,500,000;    (iii) optionally, an independent electron donor compound selected from the group consisting of vinyl ethers and compounds containing a carbon to carbon double bond attached to an aromatic ring and conjugated with the unsaturation in the ring;    (iv) optionally, an independent electron acceptor compound; and    (v) a free radial initiator;    characterized in that the film adhesive can be cured within two minutes at a temperature below 300° C.    
     
     
         20 . The film adhesive according to  claim 19  in which the rubbery polymers of (i) and (ii) are acrylics, styrene-acrylic copolymers, or acrylonitrile-butadiene copolymers, or combinations of those.  
     
     
         21 . The film adhesive according to  claim 19  in which independent electron donor compound (ii) is a vinyl ether selected from the group consisting of bis[4-(vinyloxy)butyl]terephthalate, bis[4(vinyloxy)butyl] (4-methyl-1,3-phenylene)-biscarbamate, bis[4-(vinyloxy) butyl] 1,6-hexanediylbiscarbamate, 4-(vinyloxy)-butyl stearate, and bis[4-(vinyloxy) butyl] (methylenedi-4,1-phenylene)-biscarbamate.  
     
     
         22 . The film adhesive according to  claim 19  in which the independent electron donor compound (ii) is a compound containing a carbon to carbon double bond attached to an aromatic ring and conjugated with the unsaturation in the ring and are selected from the group consisting of:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         23 . The film adhesive according to  claim 19  in which the independent electron acceptor compound (iii) is selected from the group consisting of fumarates, maleates, acrylates, and maleimides.  
     
     
         24 . The film adhesive according to  claim 19  in which the independent electron acceptor compound (iii) is a bismaleimide selected from the group consisting of N,N′-ethylene-bis-maleimide, N,N′-butylene-bis-maleimide, N,N′-phenylene-bis-maleimide, N,N′-hexamethylene-bis-maleimide, N,N′4,4′-diphenyl methane-bis-maleimide, N,N′-4,4′-diphenyl ether-bis-maleimide, N,N′-4,4′-diphenyl sulfone-bis-maleimide, N,N′-4,4′-dicyclohexyl methane-bis-maleimide, N,N′-xylylene-bis-maleimide, and N,N′-diphenyl cyclohexane-bis-maleimide.