Thermally-conductive organic additive, resin composition, and cured product

Abstract

The present invention provides a thermally-conductive organic additive which (i) is an organic polymer, unlike a thermally-conductive inorganic filler such as ceramic, metal and a carbon material, (ii) is capable of imparting thermal conductivity to plastic by being added thereto, (iii) can reduce the weight of a composition even when added to a resin in a large amount, without causing abrasion on molds and deteriorating an electrical insulation property of the composition, and (iv) provides the composition with excellent molding processability. The present thermally-conductive organic additive includes a liquid crystalline thermoplastic resin which has a mainly-chain structure, wherein a main chain of the liquid crystalline thermoplastic resin contains mainly a repeating unit represented by the general formula (1): -M-Sp-  (1) wherein M represents a mesogenic group; and Sp represents a spacer, the liquid crystalline thermoplastic resin itself having thermal conductivity of not less than 0.45 W/(m·K).

1 . A thermally-conductive organic additive comprising a liquid crystalline thermoplastic resin which has a mainly-chain structure, wherein a main chain of the liquid crystalline thermoplastic resin contains mainly a repeating unit represented by the general formula (1):
   -M-Sp-  (1)
   wherein M represents a mesogenic group; and Sp represents a spacer,   the liquid crystalline thermoplastic resin per se having a thermal conductivity of not less than 0.45 W/(m·K).   
     
     
         2 . The thermally-conductive organic additive as set forth in  claim 1 , wherein the liquid crystalline thermoplastic resin contains mainly a repeating unit represented by the general formula (2):
   -A 1 -x-A 2 -y-R-z-  (2)
   wherein each of A 1  and A 2  independently represents a substituent group selected from an aromatic group, a condensed aromatic group, an alicyclic group, and an alicyclic heterocyclic group; each of x, y and z independently represents a direct bond, or a bivalent substituent group selected from the group consisting of —CH 2 —, —C(CH 3 ) 2 —, —O—, —S—, —CH 2 —CH 2 —, —C═C—, —C≡C—, —CO—, —CO—O—, —CO—NH—, —CH═N—, —CH═N—N═CH—, —N═N—, and —N(O)═N—; and R represents a bivalent substituent group which has a main chain length of 2 to 20 atoms and may be branched.   
     
     
         3 . The thermally-conductive organic additive as set forth in  claim 2 , wherein -A 1 -x-A 2 - of the liquid crystalline thermoplastic resin is a mesogenic group represented by the general formula (3): 
       
         
           
           
               
               
           
         
         wherein X independently represents an aliphatic hydrocarbon group, F, Cl, Br, I, CN, or NO 2 ; n is an integer of 0 to 4; and m is an integer of 2 to 4. 
       
     
     
         4 . The thermally-conductive organic additive as set forth in  claim 2 , wherein R of the liquid crystalline thermoplastic resin is a linear aliphatic hydrocarbon chain. 
     
     
         5 . The thermally-conductive organic additive as set forth in  claim 4 , wherein R of the liquid crystalline thermoplastic resin has a main chain length of even-numbered carbon atoms. 
     
     
         6 . The thermally-conductive organic additive as set forth in  claim 4 , wherein R of the liquid crystalline thermoplastic resin is of at least one kind selected from —(CH 2 ) 8 —, —(CH 2 ) 10 —, and —(CH 2 ) 12 —, the liquid crystalline thermoplastic resin having a number average molecular weight of 3000 to 40000. 
     
     
         7 . The thermally-conductive organic additive as set forth in  claim 2 , wherein -y-R-z- of the liquid crystalline thermoplastic resin is —O—CO—R—CO—O—. 
     
     
         8 . A thermally-conductive organic additive containing resin composition comprising a thermally-conductive organic additive (A) as recited in  claim 1  and an organic polymer (B), wherein the thermally-conductive organic additive (A) is added in 1 part by weight to 10000 parts by weight with respect to 100 parts by weight of the organic polymer (B). 
     
     
         9 . The thermally-conductive organic additive as set forth in  claim 1 , wherein the liquid crystalline thermoplastic resin contains lamellar crystals by not less than 10 Vol %. 
     
     
         10 . The thermally-conductive organic additive as set forth in  claim 1 , wherein the liquid crystalline thermoplastic resin has a crystallinity of not less than 7 Vol %. 
     
     
         11 . A resin composition comprising:
 (A) a liquid crystalline thermoplastic resin having a mainly-chain structure, wherein a main chain of the liquid crystalline thermoplastic resin contains mainly a repeating unit represented by the general formula (1):
   -M-Sp-  (1)
 
   wherein M represents a mesogenic group; and Sp represents a spacer;   (B) a thermoplastic resin other than the liquid crystalline thermoplastic resin (A); and   (C) an inorganic filler,   wherein (A) and (B) are comprised in a weight ratio of 10:90 to 90:10 in the resin composition.   
     
     
         12 . The resin composition as set forth in  claim 11 , wherein the liquid crystalline thermoplastic resin (A) contains lamellar crystals by not less than 10 Vol %. 
     
     
         13 . The resin composition as set forth in  claim 11 , wherein the liquid crystalline thermoplastic resin (A) has a crystallinity of not less than 7 Vol %. 
     
     
         14 . A resin composition comprising:
 (A) a thermally-conductive organic additive comprising a liquid crystalline thermoplastic resin which has a mainly-chain structure, wherein a main chain of the liquid crystalline thermoplastic resin contains mainly a repeating unit represented by the general formula (1):
   -M-Sp-  (1)
 
   wherein M represents a mesogenic group; and Sp represents a spacer;   (B) a thermosetting resin; and   (C) an inorganic filler.   
     
     
         15 . A cured product obtained from a resin composition as recited in  claim 14 .