A method for bonding components of a fuel cell

Abstract

The invention is related to a method for bonding components of a PEM fuel cell with a frame and/or amongst one another, wherefore an adhesive curable by electromagnetic radiation in the range of visible light or UV is applied to the frame and/or the at least one component. The invention is characterized in that the adhesive is activated by the electromagnetic radiation and heated after the frame and/or components are brought into contact; or the frame and/or the components are brought into contact and the adhesive is exposed to electromagnetic radiation for activating and heating; to reduce its viscosity before the adhesive is finally cured. The adhesive is a cationic epoxy which contains water.

What is claimed is: 
     
         1 . A method for bonding components of a PEM fuel cell with a frame and/or amongst one another, wherefore an adhesive curable by electromagnetic radiation in the range of visible light or UV is applied to the frame and/or the at least one component, wherein the adhesive is activated by the electromagnetic radiation and heated after the frame and/or the components are brought into contact; or
 the frame and/or the components are brought into contact and the adhesive is exposed to electromagnetic radiation for activating and heating; wherein the heat reduces the viscosity of the adhesive before it is finally cured;   characterized in that   the adhesive is a cationic epoxy which contains water.   
     
     
         2 . The method according to  claim 1 ,
 wherein   the cationic epoxy has a water content of 100 to 500 ppm, preferably 200 to 450 ppm.   
     
     
         3 . The method according to  claim 1 ,
 wherein   the cationic epoxy has a viscosity of less than 100 mPas at 75° C.   
     
     
         4 . The method according to  claim 1   wherein   the heating is done up to temperatures of 100 to 200° C., preferably up to 120 to 170° C.   
     
     
         5 . The method according to  claim 1   wherein   the components of the PEM fuel cell have a microporous surface layer at least on a surface bonded to the other component and/or the frame.   
     
     
         6 . The method according to  claim 1 ,
 wherein   the heat is produced in the components through application of electromagnetic radiation, preferably in the range of visible light or UV.   
     
     
         7 . The method according to  claim 1 ,
 wherein   the adhesive is free of thermally crosslinking constituents.   
     
     
         8 . The method according to  claim 1 ,
 wherein   the components and/or the frame held one on to the other by means of a hold-down device, wherein the irradiation with electromagnetic radiation occurs through at least one window in the hold-down device, transparent to the radiation.   
     
     
         9 . The method according to  claim 8 ,
 wherein   at least one region adjacent to the transparent window in the hold-down device is cooled, in particular actively cooled.   
     
     
         10 . The method according to  claim 1 ,
 wherein   in the case of bonding a frame to a component, such as a catalyst coated membrane, the application of electromagnetic radiation at least for heating is carried out from the side of the frame through the same.   
     
     
         11 . The method according to  claim 1 ,
 wherein   in the case of bringing the frame and/or the components into contact and heating the adhesive by electromagnetic radiation, the activation and the heating is done by the electromagnetic radiation in the same single exposure of the adhesive to the electromagnetic radiation.   
     
     
         12 . Use of the method according to  claim 1 ,
 for bonding a full-surface catalyst coated membrane as one of the components, to the frame.   
     
     
         13 . Use of the method according to  claim 1 ,
 for bonding at least one gas-diffusion layer as the component with a catalyst coated membrane as a further component and/or with the frame.   
     
     
         14 . The use according to  claim 12 ,
 wherein   at least one, preferably two gas-diffusion layers are bonded to a previously bonded and cured composite of the full-surface catalyst coated membrane and the frame.   
     
     
         15 . The method according to  claim 2 , wherein the cationic epoxy has a viscosity of less than 100 mPas at 75° C. 
     
     
         16 . The method according to  claim 15 , wherein the heating is done up to temperatures of 100 to 200° C., preferably up to 120 to 170° C. 
     
     
         17 . The method according to  claim 16 , wherein the components of the PEM fuel cell have a microporous surface layer at least on a surface bonded to the other component and/or the frame. 
     
     
         18 . The method according to  claim 17 , wherein the heat is produced in the components through application of electromagnetic radiation, preferably in the range of visible light or UV. 
     
     
         19 . The method according to  claim 18 , wherein the adhesive is free of thermally crosslinking constituents. 
     
     
         20 . The method according to  claim 19 , wherein the components and/or the frame are held one on to the other by means of a hold-down device, wherein the irradiation with electromagnetic radiation occurs through at least one window in the hold-down device, transparent to the radiation.