The present invention relates to a surface treatment composition comprising, on the basis of 100 wt % of the solid part of the composition, 20-40 wt % of a water-soluble polyurethane resin, 40-60 wt % of a silane-based sol-gel resin in which three types of silane compounds are cross-linked, 5-15 wt % of a curing agent, 0.5-1.5 wt % of a corrosion inhibitor, 0.1-1.0 wt % of a molybdenum-based compound, 1.0-3.0 wt % of a silane coupling agent; 1.0-2.0 wt % of an organometallic complex, 1.0-2.0 wt % of an acid scavenger, 0.1-1.0 wt % of an aluminum-based compound, and 1.0-2.0 wt % of a lubricant. A ternary hot-dip galvannealed steel sheet treated with a chromium-free surface treatment coating agent, according to an exemplary embodiment in the present invention, has excellent resistance to blackening, alkali and corrosion, and provides excellent effects without concern for problems, in chromium treatment, of additional equipment installation, an increase in manufacturing costs and environmental pollution.

A thermal-conductive silicone composition containing (A) 0.5 to 2.5 mass % of a crosslinked silicone gel containing (a) an organopolysiloxane having at least two aliphatic unsaturated hydrocarbon groups per molecule, and having a kinematic viscosity at 25° C. of 10,000,000 mm.sup.2/s or more, and (b) an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms per molecule; (B) 12.5 to 19.5 mass % of a hydrolysable organopolysiloxane compound; and (C) 80 to 85 mass % of aluminum nitride particles having an average particle size of 0.5 pm or more and 1.5 pm or less. A content of coarse particles in the aluminum nitride particles is 1.0 volume % or less relative to the whole. The coarse particles are 10 pm or more in a particle size distribution by laser diffraction. A thermal-conductive silicone composition has excellent coating workability and favorable pumping-out resistance, and is capable of attaining low thermal resistance by being thinly compressed.

A thermally conductive sheet has a thermally conductive resin composition layer, wherein the thermally conductive resin composition layer is made of a thermally conductive resin composition (1) including an inorganic filler and a binder resin (3). The inorganic filler includes a boron nitride particle (2), the content of the inorganic filler in the thermally conductive resin composition layer is 65% by volume or more, and the boron nitride particle (2) has an average aspect ratio of 7 or less, which is calculated from a major axis and a minor axis of a primary particle measured by a specific method. The thermally conductive resin composition layer has a thickness of 200 μm or less.

A thermally conductive silicone composition contains a silicone polymer and a thermally conductive inorganic filler. The ratio X of the BET specific surface area (m.sup.2/g) to the average particle size (μm) of the thermally conductive inorganic filler is 0.1 or more. The thermally conductive inorganic filler is surface treated with a first surface treatment agent and further surface treated with a second surface treatment agent. The first surface treatment agent contains an organic silane compound represented by R.sup.11SiR.sup.12.sub.x(OR.sup.13).sub.3-x (where R.sup.11 is, e.g., a monovalent aliphatic hydrocarbon group having 1 to 4 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, R.sup.12 is, e.g., a methyl group, and R.sup.13 is, e.g., a hydrocarbon group having 1 to 4 carbon atoms). The second surface treatment agent contains a silicone polymer that has a kinematic viscosity of 1000 mm.sup.2/s or less and does not have a hydrolyzable group. Thus, the present invention provides a thermally conductive silicone composition that has improved viscoelasticity and heat resistance, and a method for producing the thermally conductive silicone composition.

A thermally conductive silicone composition contains a silicone polymer and a thermally conductive inorganic filler. The thermally conductive inorganic filler is surface treated with a first surface treatment agent and further surface treated with a second surface treatment agent. The first surface treatment agent contains an organic silane compound represented by R.sup.11SiR.sup.12.sub.x(OR.sup.13).sub.3-x (where R.sup.11 is, e.g., a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a hydrocarbon group having an alkoxysilyl group, R.sup.12 is, e.g., a methyl group, and R.sup.13 is, e.g., a hydrocarbon group having 1 to 4 carbon atoms). The second surface treatment agent contains a silicone polymer that has a kinematic viscosity of 10 to 1000 mm.sup.2/s and does not have a hydrolyzable group. Thus, the present invention provides a thermally conductive silicone composition that has a low slurry viscosity and achieves high extrudability and high moldability, and a method for producing the thermally conductive silicone composition.

A modified aluminum nitride particle comprises an aluminum nitride core and a shell surrounding the aluminum nitride core. The shell comprises a crosslinked organic polymer. Methods of making the modified aluminum nitride particle by admicellar polymerization are also disclosed.

A thermoplastic resin (A) including, in its main chain structure, a unit (i) having a biphenyl group, a unit (ii) having a substituent biphenyl group, a unit (iii) having a specific number of atoms in its main chain, and a unit (iv) having a specific number of atoms in its main chain provides a thermoplastic resin which has a low liquid crystal phase transition temperature and a low isotropic phase transition temperature, is highly thermally conductive, and can be processed by molding at a low melting temperature.

The thermosetting resin composition of the present invention includes an epoxy resin (A), a curing agent (B), and thermally conductive particles (C), in which the epoxy resin (A) includes a mesogen skeleton and has a softening point of 60° C. or lower, and a thermal conductivity λ.sub.200 of a cured product of the thermosetting resin composition at 200° C. is 12.0 W/(m.Math.K) or higher.

A composition contains the following components: (a) 15 to 49.8 volume-percent of a first polysiloxane that is has a viscosity in a range of 50 centiStokes to 550 Stokes as determined according to ASTM D4283-98; (b) 0.2 to 5 volume-percent of an organoclay; (c) 50-74 volume-percent roundish or crushed thermally conductive fillers including: (i) 5 to 15 volume-percent small thermally conductive fillers having a median particle size in a range of 0.1 to 1.0 micrometers; (ii) 10 to 25 volume-percent medium thermally conductive fillers having a median particle size in a range of 1.1 to 5.0 micrometers; (iii) 25 to 50 volume-percent large thermally conductive fillers having a median particle size in a range of 5.1 to 50 micrometers; and (d) 0 to 5 volume-percent of an alkoxy functional linear polysiloxane different from the first polysiloxane and/or an alkoxy functional linear silane; where volume-percent values are relative to composition volume.

The present application disclose a method for preparing an oriented heat conducting sheet, which includes the following steps: Step S1, preparing a fluid composition for the heat conducting sheet; Step S2, placing the fluid composition obtained in the step S1 in an orientation molding device, applying a circumferential high-speed shear force to the fluid composition layer by layer to enable thermal conducting fillers in the fluid composition to be oriented along a shear direction to form an oriented thin-layer composition, and collecting the thin-layer composition layer by layer in a die to form a continuous multi-layer aggregate; Step S3, heat curing the multi-layer aggregate to obtain an oriented composition block; and S4, slicing the oriented composition block along the direction perpendicular to an orienting direction of the oriented composition block to obtain an oriented heat conducting sheet.