THERMALLY CONDUCTIVE POLYMER COMPOSITION

1 . A thermally conductive polymer composition comprising:

(a) 30 to 60 parts by weight of a polymer, and

(b) 100 parts by weight of a boron nitride filler comprising:

(b-1) 70 to 99 parts by weight of a spherical boron nitride filler, and

(b-2) 1 to 30 parts by weight of a sheet boron nitride filler having a thickness of 5 to 500 nm, a surface area of 4 to 50 m 2 /g and an aspect ratio of 100:1 to 10000:1.

2 . The thermally conductive polymer composition of claim 1 , wherein a particle diameter (D 50 ) of the spherical boron nitride filler is 1 to 150 μm.

3 . The thermally conductive polymer composition of claim 1 , wherein a surface area of the spherical boron nitride filler is 1 to 50 m 2 /g.

4 . The thermally conductive polymer composition of claim 1 , wherein a particle diameter (D 50 ) of the sheet boron nitride filler is 1 to 50 μm.

5 . The thermally conductive polymer composition of claim 1 , wherein the polymer is selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyolefin, polyamide, polyester, AS resin, ABS resin, cyclic polyolefin, polycarbonate, polymethylpentene, polyether imide, polyphenyleneether, polyacetal, polyphenylene sulfide, liquid crystal polymer, polyallylate, polysulfone, polyether ether ketone (PEEK), polyethersulfone, polysulfone, polyamide imide, polyimide, fluorine, fluorinated resin, epoxy, novolak, isothiocyanate, melamine, urea, imide, aromatic polycarbodiimide, phenoxy, phenol, acrylic resin, vinylester, urethane, resol, silicone, acrylic polymer, polyisoprene, polybutadiene, polyisobutylene, styrene-butadiene copolymer, ethylene acrylic elastomer, nitrile elastomer (butadiene and acrylonitrile), EPDM (ethylene propylene diene) elastomer, polyurethane-polyether block copolymer, polyamide-polyether block copolymer, siloxane elastomer, chloroprene, fluoroelastomers, perfluoroelastomer, and a mixture thereof.

6 . The thermally conductive polymer composition of claim 1 , wherein a thermal conductivity of the thermally conductive polymer composition is 3.4 W/mK or higher measured according to ASTM E-1461.

7 . A thermally conductive polymer film comprising the thermally conductive polymer composition of claim 1 .

8 . The thermally conductive polymer film of claim 7 , wherein a thickness of the thermally conductive polymer film is 5 to 2000 μm.

9 . A thermally conductive polymer paste composition comprising:

(a) 30 to 60 parts by weight of a polymer, and

(b) 100 parts by weight of a boron nitride filler comprising:

(b-1) 70 to 99 parts by weight of a spherical boron nitride filler, and

(b-2) 1 to 30 parts by weight of a sheet boron nitride filler having a thickness of 5 to 500 nm, a surface area of 4 to 50 m 2 /g and an aspect ratio of 100:1 to 10000:1; and

(c) 2 to 60 parts by weight of a solvent.

10 . The thermally conductive polymer paste composition of claim 9 , wherein a particle diameter (D 50 ) of the spherical boron nitride filler is 1 to 150 μm.

11 . The thermally conductive polymer paste composition of claim 9 , wherein a surface area of the spherical boron nitride filler is 1 to 50 m 2 /g.

12 . The thermally conductive polymer paste composition of claim 9 , wherein a particle diameter (D 50 ) of the sheet boron nitride filler is 1 to 50 μm.

13 . The thermally conductive polymer paste composition of claim 9 , wherein the polymer is selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyolefin, polyamide, polyester, AS resin, ABS resin, cyclic polyolefin, polycarbonate, polymethylpentene, polyether imide, polyphenyleneether, polyacetal, polyphenylene sulfide, liquid crystal polymer, polyallylate, polysulfone, polyether ether ketone (PEEK), polyethersulfone, polysulfone, polyamide imide, polyimide, fluorine, fluorinated resin, epoxy, novolak, isothiocyanate, melamine, urea, imide, aromatic polycarbodiimide, phenoxy, phenol, acrylic resin, vinylester, urethane, resol, silicone, acrylic polymer, polyisoprene, polybutadiene, polyisobutylene, styrene-butadiene copolymer, ethylene acrylic elastomer, nitrile elastomer (butadiene and acrylonitrile), EPDM (ethylene propylene diene) elastomer, polyurethane-polyether block copolymer, polyamide-polyether block copolymer, siloxane elastomer, chloroprene, fluoroelastomers, perfluoroelastomer, and a mixture thereof.

14 . The thermally conductive polymer paste composition of claim 9 , wherein the solvent is selected from the group consisting of texanol, 1-phenoxy-2-propanol, terpineol, carbitol acetate, ethylene glycol, butyl carbitol, dibutyl carbitol, butyl acetate, dibuthyl acetate propylene glycol phenyl ether, ethylene glycol monobutyl ether and a mixture thereof.

15 . A method of manufacturing a thermally conductive polymer layer comprising:

applying a thermally conductive polymer paste composition on a substrate, the thermally conductive polymer paste composition comprising:

(a) 30 to 60 parts by weight of a polymer,

(b) 100 parts by weight of a boron nitride filler comprising:

(b-1) 70 to 99 parts by weight of a spherical boron nitride filler, and

(b-2) 1 to 30 parts by weight of a sheet boron nitride filler having thickness of 5 to 500 nm, surface area of 4 to 50 m 2 /g and aspect ratio of 100:1 to 10000:1, and

(c) 2 to 60 parts by weight of a solvent; and

drying the applied thermally conductive polymer paste composition.