Photocurable and thermosetting resin composition and printed circuit boards made by using the same

Abstract

A photocurable and thermosetting composition comprises (A) a carboxyl group-containing resin having at least one carboxyl group in its molecule, (B) a photopolymerization initiator having an oxime linkage represented by the following general formula (I), (C) a reactive diluent, and (D) an epoxy compound having two or more epoxy groups in its molecule. The above-mentioned photopolymerization initiator (B) is incorporated into a formulation which is different from at least a formulation into which the above-mentioned carboxyl group-containing resin (A) and the above-mentioned reactive diluent (C) are incorporated to formulate a system comprising at least two parts.

1 . A method of storing a multi-part photocurable and thermosetting resin composition in the form of a multi-part system comprising in combination at least two compositions, which comprises: preparing a composition containing (A) a carboxyl group-containing resin having at least one carboxyl group in its molecule and (C) a reactive diluent, and a composition containing (D) an epoxy compound having two or more epoxy groups in its molecule, and further comprising (B) a photopolymerization initiator having an oxime linkage represented by the following general formula (I), said photopolymerization initiator (B) being incorporated into a composition which is different from the composition into which said carboxyl group-containing resin (A) and said reactive diluent (C) are incorporated, and storing said compositions in individual states. 
       
         
           
           
               
               
           
         
       
     
     
         2 . The method of storing a multi-part photocurable and thermosetting resin composition according to  claim 1 , wherein said carboxyl group-containing resin (A) is a carboxyl group-containing photosensitive resin having two or more photosensitive unsaturated double bonds in its molecule. 
     
     
         3 . The method of storing a multi-part photocurable and thermosetting resin composition according to  claim 1 , wherein said photopolymerization initiator (B) having the oxime linkage represented by said general formula (I) is a compound represented by the following general formula (II): 
       
         
           
           
               
               
           
         
       
       wherein one or two of R is a group represented by the following formula (III) and the remainder is a hydrogen atom, a halogen atom, a methyl group, or a phenyl group, and X represents an oxygen atom, a sulfur atom, or a carbonyl group, 
       
         
           
           
               
               
           
         
       
       wherein R 1  represents a hydrogen atom, a methyl group, a phenyl group, a biphenyl group, or a phenyl group or biphenyl group severally substituted by an alkyl group of 1-6 carbon atoms. 
     
     
         4 . The method of storing a multi-part photocurable and thermosetting resin composition according to  claim 1 , further comprising another photopolymerization initiator (B-I) other than said photopolymerization initiator (B) and/or a sensitizer (B-II), wherein said other photopolymerization initiator (B-I) and/or said sensitizer (B-II) being incorporated into a composition which is different from the composition into which said carboxyl group-containing resin (A) and said reactive diluent (C) are incorporated. 
     
     
         5 . The method of storing a multi-part photocurable and thermosetting resin composition according to  claim 1 , wherein said reactive diluent (C) is a liquid photosensitive compound having at least one unsaturated double bond in its molecule and present in an amount of 2 to 50 parts by weight, based on 100 parts by weight of said carboxyl group-containing resin (A). 
     
     
         6 . The method of storing a multi-part photocurable and thermosetting resin composition according to  claim 1 , further comprising an inorganic filler and/or an organic filler (E), wherein said inorganic filler and/or said organic filler (E) being incorporated into either one of said compositions. 
     
     
         7 . The method of storing a multi-part photocurable and thermosetting resin composition according to  claim 1 , wherein said photopolymerization initiator (B) is a compound represented by the following general formula (IV): 
       
         
           
           
               
               
           
         
       
       wherein R 2  represents a methyl group or an ethyl group.