Varnish, prepreg, film with resin, metal foil-clad laminate, and printed circuit board

Abstract

The invention provides a varnish produced through reaction between a compound having an amino group and a resin having a functional group capable of reacting with an amino group, and having a polycyclic structure, wherein a portion of a plurality of the functional group of the resin is caused to react with the amino group of the compound in a solvent, and also a varnish produced through reaction between a compound having a phenolic hydroxyl group and a resin having a functional group capable of reacting with a phenolic hydroxyl group, and having a polycyclic structure, wherein a portion of a plurality of the functional group of the resin is caused to react with the phenolic hydroxyl group of the compound in the solvent. The invention also provides a prepreg, a resin-coated film, a metal-foil-clad laminate, and a printed wiring board produced by use of any of the varnishes.

1 . A varnish produced through reaction between a compound having an amino group and a resin having a plurality of epoxy groups, and having a polycyclic structure, wherein a portion of the plurality of the epoxy groups of the resin is caused to react with the amino group of the compound in a solvent, wherein the reaction forms a reaction product, and wherein the reaction product has a weight average molecular weight in the range of 800 to 4000. 
     
     
         2 . The varnish according to  claim 1 , which is produced through reaction between the compound having the amino group and said resin, and between a compound having a phenolic hydroxyl group and said resin, wherein another portion of the plurality of the epoxy groups of the resin is caused to react with the phenolic hydroxyl group of the compound in the solvent. 
     
     
         3 . The varnish according to  claim 1 , wherein the compound having an amino group is any of guanamine, dicyandiamide, and aminotriazine novolak. 
     
     
         4 . A varnish produced through reaction between a compound having a phenolic hydroxyl group and a resin having a plurality of epoxy groups, and having a polycyclic structure, wherein a portion of the plurality of the epoxy groups of the resin is caused to react with the phenolic hydroxyl group of the compound in a solvent, wherein the reaction forms a reaction product, and wherein the reaction product has a weight average molecular weight in the range of 800 to 4000. 
     
     
         5 . The varnish according to  claim 2 , wherein the compound having a phenolic hydroxyl group is a phenol novolak resin or a cresol novolak resin. 
     
     
         6 . The varnish according to  claim 1 , wherein the resin has at least one structure selected from the group consisting of a biphenyl structure, a naphthalene structure, a biphenyl novolak structure, an anthracene structure, and a dihydroanthracene structure. 
     
     
         7 . The varnish according to  claim 1 , the varnish containing a resin component having a structure represented by the following formula (1): 
       
         
           
           
               
               
           
         
       
       wherein R 1  represents the residue of a compound having an amino group. 
     
     
         8 . The varnish according to  claim 7 , wherein the ratio of the molar fraction of the structure represented by formula (1) to the sum of the molar fraction of the structure represented by formula (1) and that of a structure represented by the following formula (2): 
       
         
           
           
               
               
           
         
       
       is 40% or less. 
     
     
         9 . A prepreg produced by applying, to a substrate, a varnish as recited in  claim 1 , and drying the resultant product under heating. 
     
     
         10 . A prepreg according to  claim 9 , wherein the substrate is a glass woven fabric, a glass nonwoven fabric, an aramid woven fabric, or an aramid nonwoven fabric. 
     
     
         11 . A resin-coated film produced by applying, to a film, a varnish as recited in  claim 1 , and drying the resultant product under heating. 
     
     
         12 . A metal-foil-clad laminate comprising a prepreg as recited in  claim 9  and a conductor layer provided on at least one surface of the prepreg. 
     
     
         13 . A metal-foil-clad laminate comprising a resin-coated film as recited in  claim 11 , and a conductor layer provided on at least one surface of the film. 
     
     
         14 . A printed wiring board produced by forming a wiring pattern on the conductor layer provided on at least one surface of a metal-foil-clad laminate as recited in  claim 12 . 
     
     
         15 . The varnish according to  claim 4 , wherein the compound having a phenolic hydroxyl group is a phenol novolak resin or a cresol novolak resin. 
     
     
         16 . The varnish according to  claim 4 , wherein the resin has at least one structure selected from the group consisting of a biphenyl structure, a naphthalene structure, a biphenyl novolak structure, an anthracene structure, and a dihydroanthracene structure. 
     
     
         17 . A prepreg produced by applying, to a substrate, a varnish as recited in  claim 4 , and drying the resultant product under heating. 
     
     
         18 . A resin-coated film produced by applying, to a film, a varnish as recited in  claim 4 , and drying the resultant product under heating. 
     
     
         19 . A prepreg produced by applying, to a substrate, a varnish as recited in  claim 7 , and drying the resultant product under heating. 
     
     
         20 . A resin-coated film produced by applying, to a film, a varnish as recited in  claim 7 , and drying the resultant product under heating. 
     
     
         21 . The varnish according to  claim 1 , wherein the resin has at least one structure selected from the group consisting of a biphenyl structure, a biphenyl novolak structure, a naphthalene structure, a naphthalene novolak structure, an anthracene structure, and a dihydroanthracene structure. 
     
     
         22 . The varnish according to  claim 4 , wherein the resin has at least one structure selected from the group consisting of a biphenyl structure, a biphenyl novolak structure, a naphthalene structure, a naphthalene novolak structure, an anthracene structure, and a dihydroanthracene structure. 
     
     
         23 . The varnish according to  claim 1 , which further includes a solvent for said reaction product. 
     
     
         24 . The varnish according to  claim 4 , which further includes a solvent for said reaction product.