Composite dielectric material, composite dielectric substrate, prepreg, coated metal foil, molded sheet, composite magnetic substrate, substrate, double side metal foil-clad substrate, flame retardant substrate, polyvinylbenzyl ether resin composition, and method for preparing thermosetting polyvinylbenzyl ether resin composition

Abstract

A composite dielectric material comprising a resin resulting from a polyvinylbenzyl ether compound and a dielectric ceramic powder dispersed therein is useful in the high-frequency region. A composite magnetic material comprising a polyvinylbenzyl ether compound and a magnetic powder is also provided as well as a flame retardant material comprising a polyvinylbenzyl ether compound and a flame retardant. These materials may be used in the fabrication of substrates, prepreg sheets, coated metal foils, molded items, and metal foil-clad substrates.

1 - 86 . (canceled)  
   
   
       87 . A method for preparing a thermosetting polyvinylbenzyl ether resin composition, comprising the step of dissolving a polyvinylbenzyl ether compound in a solvent capable of dissolving the compound.  
   
   
       88 . A method for preparing a thermosetting polyvinylbenzyl ether resin composition, comprising the steps of dissolving a polyvinylbenzyl ether compound in a solvent capable of dissolving the compound, removing the solvent from the polyvinylbenzyl ether compound, and obtaining a composition comprising the thus treated polyvinylbenzyl ether compound.  
   
   
       89 . The method of  claim 87 , wherein the composition cures into a product having a low dielectric dissipation factor.  
   
   
       90 . The method of  claim 87 , wherein said solvent has a dielectric constant of 2 to 16.  
   
   
       91 . The method of  claim 87 , wherein the polyvinylbenzyl ether compound has the following formula (1):  
     
       
         
         
             
             
         
       
       wherein R 1  denotes methyl or ethyl, R 2  denotes hydrogen or a hydrocarbon group of 1 to 10 carbon atoms, R 3  denotes hydrogen or a vinylbenzyl group in a molar ratio of hydrogen to vinylbenzyl from 60:40 to 0:100, and n is a number of 2 to 4.  
     
   
   
       92 . A thermosetting polyvinylbenzyl ether resin composition, obtained by the method of  claim 87 , and wherein said composition cures into a product having a Q of at least 250 at a frequency of 2 GHz.