Resin composition excellent in dielectric properties, process for producing the same, varnish produced using the same, process for producing the varnish, and prepreg and metal-clad laminate using the resin composition and varnish

Abstract

A resin composition comprising a cyanate compound (A) having 2 or more cyanato groups in the molecule; a phenol compound (B); a silicone polymer (D) having at least one siloxane unit selected from the group consisting of a tri-functional siloxane unit represented by the formula RSiO 3/2 and tetra-functional siloxane unit represented by SiO 4/2 , polymerization degree of 7,000 or less, and at least one terminal functional group reactive with hydroxyl group; and inorganic filler (E).

1 . (canceled)  
   
   
       2 . A varnish comprising a resin composition including a cyanate compound (A) having 2 or more cyanato groups in the molecule; a phenol compound (B); a polyphenylene ether resin (C); a silicone polymer (D) having at least one siloxane unit selected from the group consisting of a tri-functional siloxane unit represented by the formula RSiO 3/2  (wherein, R is an organic group, and when 2 or more Rs are present in the silicone polymer, they may be the same or different) and tetra-functional siloxane unit represented by Si0 4/2 , polymerization degree of 7,000 or less and at least one terminal functional group reactive with hydroxyl group; and inorganic filler (E), treated with said silicone polymer (D), dissolved or dispersed in a solvent, wherein the non-volatile content of the varnish is 54% by weight or more.  
   
   
       3 . The varnish according to  claim 2 , wherein the equivalent ratio of said phenol compound (B) to cyanate compound (A) is 0.025 to 0.30 as the ratio of the phenolic hydroxylic group in said phenol compound (B) to cyanato group in said cyanate compound (A) (hydroxylic group/cyanato group ratio); said polyphenylene ether resin (C) is incorporated at 1 to 300 parts by weight per 100 parts by weight of said cyanate compound (A); said silicone polymer (D) is incorporated at 0.01 to 20% by weight on said inorganic filler (E); and said inorganic filler (E) is incorporated at 1 to 1,000 parts by weight per 100 parts by weight of total of said cyanate compound (A), phenol compound (B) and polyphenylene ether resin (C).  
   
   
       4 . A varnish comprising a resin composition including a cyanate compound (A) having 2 or more cyanato groups in the molecule; a phenol compound (B); a polyphenylene ether resin (C); and an inorganic filler (F) surface-treated with a silicone polymer (D) having at least one siloxane unit selected from the group consisting of a tri-functional siloxane unit represented by the formula RSiO 3/2  (wherein, R is an organic group, and when 2 or more Rs are present in the silicone polymer, they may be the same or different) and tetra-functional siloxane unit represented by Si0 4/2 , polymerization degree of 7,000 or less and at least one terminal functional group reactive with hydroxyl group, dissolved or dispersed in a solvent, wherein the non-volatile content of the varnish is 54% by weight or more.  
   
   
       5 . The varnish according to  claim 4 , wherein the equivalent ratio of said phenol compound (B) to cyanate compound (A) is 0.025 to 0.30 as the ratio of the phenolic hydroxylic group in said phenol compound (B) to the cyanato group in said cyanate compound (A) (hydroxylic group/cyanato group ratio); said polyphenylene ether resin (C) is incorporated at 1 to 300 parts by weight per 100 parts by weight of said cyanate compound (A); and said inorganic filler (F) is incorporated at 1 to 1,000 parts by weight per 100 parts by weight of total of said cyanate compound (A), phenol compound (B) and polyphenylene ether resin (C).  
   
   
       6 . A varnish comprising a resin composition including a phenol-modified cyanate ester oligomer produced by reacting a cyanate compound (A) having 2 or more cyanato groups in the molecule with a phenol compound (B) at an equivalent ratio of the phenolic hydroxylic group in the phenol compound (B) to the cyanato group in the cyanate compound (A) (hydroxylic group/cyanato group ratio) in a range from 0.01 to 0.30; phenol compound (B) incorporated at a hydroxylic group/cyanato group equivalent ratio in a range below 0.29 (this equivalent ratio is in a range from 0.025 to 0.30, with this phenol compound (B) combined with the phenol compound (B) used for production of the phenol-modified cyanate ester oligomer); polyphenylene ether resin (C); and inorganic filler (F) surface-treated with a silicone polymer (D) having at least one siloxane unit selected from the group consisting of a tri-functional siloxane unit represented by the formula RSiO 3/2  (wherein, R is an organic group, and when 2 or more Rs are present in the silicone polymer, they may be the same or different) and tetra-functional siloxane unit represented by SiO 4/2 , polymerization degree of 7,000 or less, and at least terminal functional group reactive with hydroxyl group, dissolved or dispersed in a solvent, wherein the non-volatile content of the varnish is 54% by weight or more.  
   
   
       7 . The varnish according to  claim 6 , wherein said polyphenylene ether resin (C) is incorporated at 1 to 300 parts by weight per 100 parts by weight of said cyanate compound (A); and said inorganic filler (F) is incorporated at 1 to 1,000 parts by weight per 100 parts by weight of total of said cyanate compound (A), phenol compound (B) and polyphenylene ether resin (C).  
   
   
       8 . A varnish comprising a resin composition including a phenol-modified cyanate ester oligomer containing a polyphenylene ether resin, produced by reacting a cyanate compound (A) with a phenol compound (B) in the presence of a polyphenylene ether resin (C) at an equivalent ratio of the phenolic hydroxylic group in the phenol compound (B) to the cyanato group in the cyanate compound (A) (hydroxylic group/cyanato group ratio) in a range from 0.01 to 0.30; phenol compound (B) incorporated at an equivalent ratio of the phenolic hydroxylic group in the phenol compound (B) to the cyanato group in the cyanate compound (A) (hydroxylic group/cyanato group ratio) in a range below 0.29 (this equivalent ratio is in a range from 0.025 to 0.30, with this phenol compound (B) combined with the phenol compound (B) used for production of the phenol-modified cyanate ester oligomer); and inorganic filler (F) surface-treated with a silicone polymer (D) having at least one siloxane unit selected from the group consisting of a tri-functional siloxane unit represented by the formula RSiO 3/2  (wherein, R is an organic group, and when 2 or more Rs are present in the silicone polymer, they may be the same or different) and tetra-functional siloxane unit represented by SiO 4/2 , polymerization degree of 7,000 or less, and at least one terminal functional group reactive with hydroxyl group, dissolved or dispersed in a solvent, wherein the non-volatile content of the varnish is 54% by weight or more.  
   
   
       9 . The varnish according to  claim 8 , wherein said polyphenylene ether resin (C) is incorporated at 1 to 300 parts by weight per 100 parts by weight of said cyanate compound (A); and said inorganic filler (F) is incorporated at 1 to 1,000 parts by weight per 100 parts by weight of total of said cyanate compound (A), phenol compound (B) and polyphenylene ether resin (C).  
   
   
       10 . The varnish according to  claim 6 , wherein said cyanate compound (A) is reacted to have a conversion of 10 to 70% by mol to produce said phenol-modified cyanate ester oligomer, or phenol-modified cyanate ester oligomer containing a polyphenylene ether resin.  
   
   
       11 . The varnish according to  claim 2 , wherein said cyanate compound (A) is at least one compound selected from those represented by the following formula (Ia):  
     
       
         
         
             
             
         
       
       (wherein, R 1  is an alkylene group of 1 to 3 carbon atoms, which may be substituted by a halogen atom, or represented by the general formula (II) or (III); R 2  and R 3  are each hydrogen atom on an alkyl group of 1 to 4 carbon atoms, and may be the same or different; and R 4  is an alkylene group of 1 to 3 carbon atoms):  
       
         
           
           
               
               
           
         
       
     
   
   
       12 . The varnish according to  claim 11 , wherein said cyanate compound having 2 or more cyanato groups in the molecule represented by the formula (I) is selected from the group consisting of 2,2-bis(4-cyanatophenyl)propane, bis(4-cyanatophenyl)ethane, bis(3,5-dimethyl-4-cyanatophenyl)methane, 2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane, α,α′-bis(4-cyanatophenyl)-m-diisopropylbenzene, and cyanate-esterified phenol-added dicyclopentadiene polymer.  
   
   
       13 . The varnish according to  claim 2 , wherein said phenol compound (B) is at least one selected from the compounds represented by the following formula (IV) or (Va):  
     
       
         
         
             
             
         
       
       (wherein, R 5  and R 6  are each hydrogen atom or methyl group, and may be the same or different; and “m” is an integer of 1 to 3)  
       
         
           
           
               
               
           
         
       
       (wherein, R 7  is hydrogen atom or methyl group; R 8  is methyl, ethyl or 2,2-dimethylpropyl; and “n” is an integer of 1 to 2).  
     
   
   
       14 . The varnish according to  claim 13 , wherein said phenol compound represented by the formula (IV) is at least one compound selected from the group consisting of p-(α-cumyl)phenol, and mono-, di- and tri-α-methylbenzyl)phenol.  
   
   
       15 . The varnish according to  claim 13 , wherein said phenol compound represented by the formula (Va) is at least one compound selected from the group consisting of p-tert-butylphenol, 2,4- or 2,6-di-tert-butylphenol, p-tert-aminophenol and p-tert-octylphenol.  
   
   
       16 . The varnish according to  claim 2 , wherein said polyphenylene ether resin (C) is an alloyed polymer of poly(2,6-dimethyl-1,4-phenylene) ether and polystyrene, or alloyed polymer of poly(2,6-dimethyl-1,4-phenylene) ether and styrene/butadiene copolymer which contains the poly(2,6-dimethyl-1,4-phenylene) ether at 50% or more.  
   
   
       17 . The varnish according to  claim 2 , wherein said silicone polymer (D) is composed of the tri-functional siloxane unit represented by the formula RSiO 3/2 , and has a polymerization degree of 2 to 7,000.  
   
   
       18 . The varnish according to  claim 2 , wherein said silicone polymer (D) is composed of the tetra-functional siloxane unit represented by the formula Si0 4/2  and has a polymerization degree of 7,000 or less.  
   
   
       19 . The varnish according to  claim 2 , wherein said silicone polymer (D) is composed of a bi-functional siloxane unit represented by the formula R 2 SiO 2/2  (wherein, R 2  is the same as R) and the tetra-functional siloxane unit, and has a polymerization degree of 7,000 or less.  
   
   
       20 . The varnish according to  claim 2 , wherein said silicone polymer (D) is composed of the tri- and tetra-functional siloxane unit, and has a polymerization degree of 7,000 or less.  
   
   
       21 . The varnish according to  claim 2 , wherein said silicone polymer (D) is composed of the bi-functional siloxane unit represented by the formula R 2 SiO 2/2  (wherein, R 2  is the same as R) and the tri-functional siloxane unit, and has a polymerization degree of 7,000 or less.  
   
   
       22 . The varnish according to  claim 2 , wherein said silicone polymer (D) is composed of the bi-functional siloxane unit represented by the formula R 2 SiO 2/2  (wherein, R 2  is the same as R) and tri- and tetra-functional siloxane unit, and has a polymerization degree of 7,000 or less.  
   
   
       23 . The varnish according to  claim 2 , wherein the tetra-functional siloxane unit accounts for 15% by mol or more of the total siloxane units.  
   
   
       24 . The varnish according to  claim 2 , wherein the tri-functional siloxane unit accounts for 15% by mol or more of the total siloxane units.  
   
   
       25 . The varnish according to  claim 2 , wherein said inorganic filler (E) is at least one selected from the group consisting of alumina, titanium oxide, mica, silica, beryllia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay, talc, aluminum borate, and silicon carbide.  
   
   
       26 . The varnish according to  claim 4 , wherein said inorganic filler (F) is surface-treated with a coupling agent together with the silicone polymer (D).  
   
   
       27 . The varnish according to  claim 26 , wherein said coupling agent is a silane-based one.  
   
   
       28 . The varnish according to  claim 26 , wherein said coupling agent is a titanate-based one.  
   
   
       29 . The varnish according to  claim 2 , wherein a flame-retardant (G) is incorporated as a component.  
   
   
       30 . The varnish according to  claim 29 , wherein said flame-retardant (G) has no reactivity with said cyanate compound (A).  
   
   
       31 . The varnish according to  claim 29 , wherein said flame-retardant (G) is at least one alicyclic one selected from the group consisting of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane, tetrabromocyclooctane and hexabromocyclododecane.  
   
   
       32 . The varnish according to  claim 29 , wherein said flame-retardant (G) is at least one selected from the group consisting of bis(tribromophenoxy)ethane, a brominated triphenylcyanurate represented by the formula (VI), brominated polyphenylene ether represented by the formula (VII) and brominated polystyrene represented by the formula (VIII):  
     
       
         
         
             
             
         
       
       (wherein, “l,” “m,” and “n” are each an integer of 1 to 5)  
       
         
           
           
               
               
           
         
       
       (wherein, “n” is an integer)  
       
         
           
           
               
               
           
         
       
       (wherein, “m” is an integer of 1 to 5, and “n” is an integer).  
     
   
   
       33 . The varnish according to  claim 2 , further including an epoxy resin (H) having two or more glycidyl in the molecule.  
   
   
       34 . The varnish according to  claim 33 , wherein said epoxy resin (H) is at least one selected from the group consisting of bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, biphenyl type epoxy resin, epoxy resin having a naphthalene structure, epoxy resin having an aralkyl structure, epoxy resin represented by the formula (IX) and epoxy resin having a cyclopentadiene structure, represented by the formula (X):  
     
       
         
         
             
             
         
       
       (wherein, R 9  is hydrogen atom or an alkyl group of 1 to 4 carbon atoms; R 10  is an alkyl group of 1 to 4 carbon atoms; and “n” is an average of 1 to 7)  
       
         
           
           
               
               
           
         
       
       (wherein, “n” is an integer).  
     
   
   
       35 . The varnish according to  claim 2 , wherein an antioxidant (I) selected from the group consisting of a phenol-based one and organosulfur-based one is incorporated as a component.  
   
   
       36 . The varnish according to  claim 35 , wherein said phenol-based antioxidant (I) is a bisphenol-based one.  
   
   
       37 . A process for producing a varnish, wherein the cyanate compound (A) or the phenol-modified cyanate ester oligomer according to  claim 6  and phenol compound (B) are incorporated in a treatment solution containing the silicone polymer (D) and inorganic filler (E), in which the inorganic filler (E) is surface-treated, and wherein the non-volatile content of the varnish is 54% by weight or more.  
   
   
       38 . A process for producing a varnish, wherein the cyanate compound (A) or phenol-modified cyanate ester oligomer according to  claim 6  and phenol compound (B) are dissolved or dispersed in the solvent, and the resultant solution or dispersion is incorporated with the inorganic filler (F) surface-treated with the silicone polymer (D) or a treatment solution containing the inorganic filler (F) in which the inorganic filler (F) is surface-treated with the silicone polymer (D), wherein the non-volatile content of the varnish is 54% by weight or more.  
   
   
       39 . A process for producing a varnish, comprising: 
 surface treating inorganic filler (E) in a treatment solution containing silicone polymer (D), and    incorporating resultant treatment solution containing the inorganic filler with    (1) cyanate compound (A) or a phenol-modified cyanate oligomer produced by reacting the cyanate compound (A) with phenol compound (B), and phenol compound (B) and polyphenylene ether resin (C), or    (2) phenol-modified cyanate oligomer containing polyphenylene ether resin produced by reacting the cyanate compound (A) with the phenol compound (B) in the presence of the polyphenylene ether resin (C), and phenol compound (B), wherein the non-volatile content of the varnish is 54% by weight or more.    
   
   
       40 . A process for producing a varnish, wherein 
 (1) cyanate compound (A) or a phenol-modified cyanate oligomer produced by reacting the cyanate compound (A) with the phenol compound (B), and phenol compound (B) and polyphenylene ether resin (C), or    (2) phenol-modified cyanate oligomer containing polyphenylene ether resin produced by reacting the cyanate compound (A) with the phenol compound (B) in the presence of the polyphenylene ether resin (C)    are dissolved or dispersed in a solvent, and resultant solution or dispersion is incorporated with inorganic filler (F) surface-treated with silicone polymer (D) or a treatment solution containing the inorganic filler (F) in which the inorganic filler (F) is surface-treated with the silicone polymer (D), wherein the non-volatile content of the varnish is 54% by weight or more.    
   
   
       41 . The process for producing a varnish according to  claim 40 , wherein said phenol-modified cyanate oligomer containing the polyphenylene ether resin is produced by reacting the cyanate compound (A) with the phenol compound (B) in the presence of the polyphenylene ether resin (C) in the solution or dispersion in which the polyphenylene ether resin (C) is dissolved or dispersed beforehand at an equivalent ratio of the phenolic hydroxylic group in the phenol compound (B) to the cyanato group in the cyanate compound (A) (hydroxylic group/cyanato group ratio) in a range from 0.01 to 0.30.  
   
   
       42 . A process for producing a varnish, wherein the varnish produced by the process according to  claim 37  is further incorporated with flame-retardant (G), epoxy resin (H) and/or antioxidant (I).  
   
   
       43 . A prepreg which is obtainable by impregnating a base material with the varnish according to  claim 2 , and then drying the same at 80 to 200° C.  
   
   
       44 . A metal-clad laminate comprising one or more sheets of the prepreg according to  claim 43 , placed one on another to produce the laminate when two or more sheets are used, wherein the sheet or laminate is coated with a metal-clad at least on one side and heated under pressure.  
   
   
       45 . The varnish according to  claim 25 , wherein said inorganic filler (E) is clay, and the clay is fired clay.  
   
   
       46 . The varnish according to  claim 2 , wherein said solvent is at least one selected from the group consisting of alcohols, ketones, aromatic hydrocarbons, esters and amides.  
   
   
       47 . The varnish according to  claim 2 , wherein the phenol compound (B) is a monovalent phenol compound.  
   
   
       48 . The varnish according to  claim 6 , wherein said phenol-modified cyanate ester includes triazine rings containing a component derived from the phenol compound (B).  
   
   
       49 . The varnish according to  claim 48 , wherein a number of cyanato groups extending from a respective triazine ring is 1 or 2.  
   
   
       50 . The varnish according to  claim 6 , wherein the phenol compound (B) is a monovalent phenol compound.  
   
   
       51 . An article of manufacture comprising a plurality of prepregs, at least one of said plurality of prepregs being formed by a process of impregnating a base material for a prepreg with the varnish of  claim 2 , to form an impregnated base material, and drying the impregnated base material, the plurality of prepregs being laminated to each other to form a laminate of prepregs.  
   
   
       52 . The article of manufacture according to  claim 51 , further comprising a metal layer on the laminate of prepregs, thereby forming a metal-clad laminate.  
   
   
       53 . The article of manufacture according to  claim 52 , wherein the metal layer is a wiring layer, and the article of manufacture is a printed wiring board.  
   
   
       54 . An article of manufacture comprising a plurality of prepregs, at least one of said plurality of prepregs being formed by a process of impregnating a base material for a prepreg with the varnish of  claim 4 , to form an impregnated base material, and drying the impregnated base material, the plurality of prepregs being laminated to each other to form a laminate of prepregs.  
   
   
       55 . The article of manufacture according to  claim 54 , further comprising a metal layer on the laminate of prepregs, thereby forming a metal-clad laminate.  
   
   
       56 . The article of manufacture according to  claim 55 , wherein the metal layer is a wiring layer, and the article of manufacture is a printed wiring board.  
   
   
       57 . The varnish according to  claim 2 , wherein the non-volatile content of the varnish is 63% by weight or less.  
   
   
       58 . The varnish according to  claim 4 , wherein the non-volatile content of the varnish is 63% by weight or less.  
   
   
       59 . The varnish according to  claim 6 , wherein the non-volatile content of the varnish is 63% by weight or less.  
   
   
       60 . The varnish according to  claim 8 , wherein the non-volatile content of the varnish is 63% by weight or less.  
   
   
       61 . The process according to  claim 37 , wherein the non-volatile content of the varnish is 63% by weight or less.  
   
   
       62 . The process according to  claim 38 , wherein the non-volatile content of the varnish is 63% by weight or less.  
   
   
       63 . The process according to  claim 39 , wherein the non-volatile content of the varnish is 63% by weight or less.  
   
   
       64 . The process according to  claim 40 , wherein the non-volatile content of the varnish is 63% by weight or less.