Photoreactive hot-melt adhesive composition

Abstract

It is an object to provide a photoreactive hot-melt adhesive composition which exhibits high adhesive strength immediately after combination of adherends and excellent bond strength after completion of curing and provides a highly durable bonded laminate. A photoreactive hot-melt adhesive composition containing: (a) a bisphenol F epoxy resin that assumes a solid form at ordinary temperature; (b) at least one compound selected from the group consisting of a compound represented by the following formula (1), a copolymer of tetramethylene oxide and ethylene oxide and a copolymer of tetramethylene oxide and propylene oxide; and (c) a cationic photoinitiator; R1−(OR2) n −OR3   Formula (1) (In the formula, R1 and R3 independently represent any of a hydrogen atom, a glycidyl group, and a monofunctional substituted or unsubstituted hydrocarbon group having 1-8 carbon atoms; R2 represents a bifunctional, substituted or unsubstituted hydrocarbon group having 2-8 carbon atoms; and n is an integer of 2 or larger. In (OR2) n , R2's of OR2's may be all identical to or different from each other).

1 . A photoreactive hot-melt adhesive composition containing: 
 (a) a bisphenol F epoxy resin that assumes a solid form at ordinary temperature;    (b) a compound having a polyoxyalkylene group in its main chain and any of a hydroxyl group, an epoxy group and an alkoxyl group containing 1-8 carbon atoms at its terminal; and    (c) a cationic photoinitiator.    
     
     
         2 . A photoreactive hot-melt adhesive composition containing: 
 (a) a bisphenol F epoxy resin that assumes a solid form at ordinary temperature;    (b) at least one compound selected from the group consisting of a compound represented by the following formula (1), a copolymer of tetramethylene oxide and ethylene oxide and a copolymer of tetramethylene oxide and propylene oxide; and    (c) a cationic photoinitiator;    R1—(OR2) n —OR3   Formula (1)    (In the formula, R1 and R3 independently represent any of a hydrogen atom, a glycidyl group and a monofunctional substituted or unsubstituted hydrocarbon group having 1-8 carbon atoms; R2 represents a bifunctional, substituted or unsubstituted hydrocarbon group having 2-8 carbon atoms; and n is an integer of 2 or larger. In (OR2) n , R2's of OR2's may be all identical to or different from each other.)    
     
     
         3 . The photoreactive hot-melt adhesive composition as recited in  claim 2 , wherein said compound (b) is the compound represented by the formula (1).  
     
     
         4 . The photoreactive hot-melt adhesive composition as recited in  claim 3 , wherein said compound represented by the formula (1) is polytetramethylene ether glycol or polyethylene glycol.  
     
     
         5 . The photoreactive hot-melt adhesive composition as recited in  claim 3 , wherein said compound represented by the formula (1) is polyethylene glycol diglycidyl ether.  
     
     
         6 . The photoreactive hot-melt adhesive composition as recited in  claim 2 , wherein said compound (b) is a copolymer of tetramethylene oxide and ethylene oxide.  
     
     
         7 . The photoreactive hot-melt adhesive composition as recited in  claim 1  or  2 , wherein said compound (b) is a copolymer of tetramethylene oxide and propylene oxide.  
     
     
         8 . The photoreactive hot-melt adhesive composition as recited in any one of claims  1 - 7 , characterized as further containing a cationically polymerizable resin that assumes a liquid form at ordinary temperature.  
     
     
         9 . The photoreactive hot-melt adhesive composition as recited in  claim 8 , wherein said cationically polymerizable resin that assumes a liquid form at ordinary temperature is a bisphenol A epoxy resin or a hydrogenated bisphenol A epoxy resin.  
     
     
         10 . The photoreactive hot-melt adhesive composition as recited in  claim 8 , wherein said cationically polymerizable resin is a resin having a structure including an alkylene oxide skeleton and represented by the following formula (2);  
       
         
           
           
               
               
           
         
       
       (in the formula, R 4  and R 5  independently represent a hydrogen atom or a methyl group; R 6  and R 7  independently represent a cationically polymerizable, reactive group represented by the following formula (3); Y represents an alkylene group; and m and n independently represent 0 or a positive integer of 1 or larger);  
       
         
           
           
               
               
           
         
       
       (in the formula, R 8 , R 9 , R 10 , and R 11  independently represent any of a hydrogen atom and methyl, ethyl, isopropyl, isoamyl and phenyl groups; R 12 , R 13  and R 14  independently represent any of a hydrogen atom and organic groups; and m and n independently represent 0, 1 or 2).  
     
     
         11 . The photoreactive hot-melt adhesive composition as recited in any one of claims  2 - 4  and  8 - 10 , wherein said compound represented by the formula (1) is not an epoxy compound and incorporated in the amount of 5-40 parts by weight, based on 100 parts by weight of all epoxy resins.  
     
     
         12 . The photoreactive hot-melt adhesive composition as recited in any one of claims  2 ,  3 ,  5  and  8 - 10 , wherein said compound represented by the formula (1) is an epoxy compound and incorporated in the amount of 5-40 parts by weight, based on 100 parts by weight of all epoxy resins excepting the compound represented by the formula (1).  
     
     
         13 . The photoreactive hot-melt adhesive composition as recited in any one of claims  2  and  6 - 10 , wherein said compound (b) is a copolymer of tetramethylene oxide and ethylene oxide or a copolymer of tetramethylene oxide and propylene oxide and incorporated in the amount of 1-40 parts by weight, based on 100 parts by weight of all epoxy resins.  
     
     
         14 . The photoreactive hot-melt adhesive composition as recited in any one of claims  1 - 13 , wherein a polyester compound that assumes a solid form at ordinary temperature is excluded.