Filler-loaded high thermal conductive dispersion liquid composition having excellent segregation stability, method for producing said dispersion liquid composition, filler-loaded high thermal conductive material using said dispersion liquid composition, method for producing said material, and molded article obtained using said material

A method for producing a filler-loaded high thermal conductive material, the method comprising:

• a step (1) of obtaining a powder composition, which contains organic polymer particles containing thermoplastic polymer particles, and high thermal conductive filler particles which contain graphite-like filler particles selected from the group consisting of a graphite, hexagonal boron nitride, hexagonal silicon carbide, molybdenum disulfide, tungsten disulfide, and mixtures thereof, by pulverizing 5 to 70 parts by weight of the organic polymer particles and 30 to 95 parts by weight of the high thermal conductive filler particles with respect to 100 parts by weight of the total amount of these components by using a pulverizing machine, which performs grinding with frictional force or impact force, to cause delamination or cohesive failure while maintaining an average planar particle size of the graphite-like filler particles having a graphite-like structure, in the powder composition, the vicinity of the high thermal conductive filler particles being covered with the micronized organic polymer particles and the covered particles being uniformly dispersed;
• a step (2) of uniformly dispersing the powder composition using 25 to 250 parts by weight of a liquid reactive dispersing medium and/or a dispersing medium containing a thermoplastic polymer having a deflection temperature under load or a melting point lower than that of the thermoplastic polymer particles used in the powder composition by 5 to 150° C. with respect to 100 parts by weight of the powder composition to prepare a dispersion liquid composition having conditions that a thermal conductive infinite cluster exhibiting a thermal conductivity of 1 to 35 W/mK is formed and a concentration of the high thermal conductive filler particles is equal to or more than a percolation threshold;
• a crosslinking step (3) of allowing the dispersion liquid composition to react under a condition that the liquid reactive dispersing medium forms a crosslinked polymer when the dispersing medium comprises the liquid reactive dispersing medium;
• a fluidizing step (4) of fluidizing the thermoplastic polymer used in the dispersing medium at a temperature that is equal to or lower than a deflection temperature under load or a melting point of the thermoplastic polymer used in the powder composition and is equal to or higher than a deflection temperature under load or a melting point of the thermoplastic polymer used in the dispersing medium when the dispersing medium comprises the thermoplastic resin;
• a step (5) of molding by heating the material formed in the crosslinking step (3) and/or the fluidizing step (4) at a pressure of 0 to 1000 kgf/cm2 and at a temperature equal to or higher than a deflection temperature under load or a melting point of the thermoplastic polymer particles used in the powder composition;
• and
• a step (6) of cooling and solidifying the material formed in the step (5).