JP6221490B2 - Easily deformable aggregate and method for producing the same, heat conductive resin composition, heat conductive member and method for producing the same, and heat conductive adhesive sheet - Google Patents

Description

  The present invention relates to an easily deformable aggregate having thermal conductivity and a method for producing the same, a thermally conductive resin composition containing the easily deformable aggregate, and thermal conductivity produced using the thermally conductive resin composition. It is related with a member, its manufacturing method, and a heat conductive adhesive sheet.

In recent years, the development of the electronics field has been remarkable, and in particular, electronic devices have been reduced in size, weight, density, and output, and demands for these performances have become increasingly sophisticated. In order to increase the density of electronic circuits, high insulation reliability and miniaturization are required. In addition, there is a strong demand for improvement in heat dissipation for preventing deterioration of electronic equipment due to heat generation associated with higher output of electronic equipment.
In the electronics field, a polymer material is suitably used as an insulating material. Therefore, in order to improve heat dissipation, it is desired to improve the thermal conductivity of the polymer material. Although there is a limit to improving the thermal conductivity (heat dissipation) of the polymer material, the thermal conductivity (heat dissipation) can be improved by mixing the thermally conductive particles with the polymer material. Such a material can be suitably used for a heat conductive member such as an adhesive sheet or a pressure sensitive adhesive sheet having heat conductivity.

For example, Patent Document 1 discloses a molding resin containing a nanocomposite polyamide resin in which a layered silicate is uniformly dispersed and a thermally conductive inorganic filler. As the thermally conductive inorganic filler, alumina, magnesium oxide, silica, zinc oxide, boron nitride, silicon carbide, silicon nitride and the like are disclosed.
Thermally conductive inorganic fillers are required to have improved thermal conductivity so that the molded body can be imparted with thermal conductivity with a smaller amount than in the past.

Patent Document 2 discloses a method of obtaining spherical composite particles having an average particle diameter of 3 to 85 μm with improved thermal conductivity by granulating and sintering high thermal conductivity particles having an average particle diameter of 10 μm or less. It is disclosed.
Specifically, after heat-conductive particles such as alumina, aluminum nitride, or crystalline silica are coated with a silane coupling agent or a thermosetting resin, the heat conductivity is 800 ° C. or higher, preferably 1000 to 2800 ° C. Has been proposed (see paragraphs [0009], [0021] to “0022” and [0028] to [0032]).
According to Patent Document 2, it is described that sintering is performed in order to increase the cohesive force of the composite particles. However, as a result of sintering at a temperature close to the melting point of the thermally conductive particles after granulation, the binder used during granulation disappears. Therefore, the cohesive force of the composite particles after sintering is never high. Rather, the composite particles after sintering are brittle and cannot maintain a granulated state, and are easy to collapse.
If it is sufficiently sintered at a temperature higher than the melting point, the heat conductive particles are fused and integrated so that a high cohesive force can be obtained. End up.

  Patent Document 3 discloses a powder composition containing inorganic powder such as alumina, magnesium oxide, boron nitride, or aluminum nitride and a thermosetting resin composition, and processed into powder, granulated powder, or granules. Has been. However, since the used inorganic powder has a large size and uses a thermosetting resin composition, the resin is cured in the aggregate to obtain a hard powder composition having strong bonds. .

  In Patent Document 4, composite particle powder obtained by coating the surface of alumina particle powder with a surface modifier and further attaching carbon powder to the surface is heated and fired at 1350 to 1750 ° C. in a nitrogen atmosphere. (See [Claims], paragraphs [0034], [0042], [0046] to [0049]).

  Patent Document 5 discloses a spherical aluminum nitride sintered powder having an average particle diameter of 10 to 500 μm and a porosity of 0.3% or more. Specifically, a slurry containing an aluminum nitride powder containing 10% by mass or more of a powder having a primary particle size of 0.1 to 0.8 μm and a sintering aid such as lithium oxide or calcium oxide is spray-dried, Furthermore, a method for producing a spherical aluminum nitride sintered powder fired at 1400 to 1800 ° C. is described (see claims 1 and 4, paragraph [0035]).

  Similarly to Patent Document 2, Patent Documents 4 and 5 are sintered at a high temperature, and the sintering aid or the like and aluminum nitride are firmly bonded. Integrated large and hard aluminum nitride particles are obtained.

Patent Document 6 discloses a secondary aggregate obtained by isotropic aggregation of primary particles of flaky boron nitride.
Specifically, after calcining the flaky boron nitride at around 1800 ° C., the granule composed of primary particles obtained by pulverization is fired at 2000 ° C., the porosity is 50% or less, and the average pore diameter is A method for obtaining a secondary aggregate having a strength of 0.05 to 3 μm is disclosed (see paragraphs [0010], [0011] [0014], [0026], and “0027”).

  In Patent Document 7, a spherical boron nitride aggregate obtained by agglomerating irregularly shaped non-spherical boron nitride particles is fired at 1800 to 2100 ° C., and the ratio of the fracture strength to the bulk strength is less than 6.5 MPa · cc / g. Disclosed is a method in which spherical boron nitride is not pulverized to a preferred size range, further subjected to surface treatment, and used as a filler for a thermally conductive composition. (Paragraphs [0012], [0016], [0017], [0026])

  Patent Document 8 discloses a silicon nitride sintered body, and Patent Document 9 discloses a spherical zinc oxide particle powder that has been subjected to a sintering process.

However, as the demand for heat dissipation increases, conventional thermal conductive particles or granulated bodies thereof cannot sufficiently meet the demand.
Therefore, there has been a demand for a material for imparting thermal conductivity, which can provide the same level of thermal conductivity as before with a smaller amount of use, or can provide higher thermal conductivity with the amount of use as conventional. ing.

  On the other hand, as a heat conductive member using heat conductive particles, for example, Patent Documents 10 and 11 disclose heat conductive adhesive sheets using inorganic particles. In order to increase the thermal conductivity of such a thermal conductive member, it is effective to increase the filling rate of the particles. However, as the amount of the particles decreases, the amount of the polymer material decreases. Decrease in substrate followability occurs. In particular, in adhesive sheet applications, the adhesive component is reduced by increasing the filling rate, and the adhesiveness is lost.

  Patent Documents 12 and 13 disclose a method for controlling the orientation of particles by applying a magnetic field or an electric field to a thermally conductive member in order to form contact (heat transfer path) of particles with a low particle filling rate. Yes. However, this method is not practical when considering industrialization.

  Patent Document 14 discloses a method in which secondary particles are arranged close to each other in a coating film to form a tertiary aggregate and exhibit high thermal conductivity with a low filling amount. In this document, a silane coupling agent is used as a binder for granulation, and the secondary particles are dried at 150 ° C. for 4 hours or more to cause a coupling reaction, whereby operability as a granulated body. However, the flexibility of the particles is lost. Therefore, both thermal conductivity and adhesive strength are insufficient.

As described above, in the heat conductive resin composition using the conventional heat conductive particles or the secondary particles (aggregates), high heat conductivity and excellent film formability, substrate followability of the obtained film Is difficult to achieve.
Moreover, in the adhesive sheet, in the heat conductive resin composition using the conventional heat conductive particles or the secondary particles (aggregates), high heat conductivity and excellent film formability, obtained film base material It is difficult to achieve followability and adhesion.

JP 2006-342192 A JP-A-9-59425 JP 2000-239542 A JP 2006-256940 A JP 2006-206393 A JP 2010-157563 A Japanese translation of PCT publication No. 2008-510878 Japanese Patent Laid-Open No. 2007-039306 JP 2009-249226 A JP-A-6-162855 JP 2004-217861 A JP 2006-335957 A JP 2007-332224 A JP 2010-84072 A

An object of the present invention is to provide a thermal conductivity-imparting material that can impart the same level of thermal conductivity as before with a smaller amount of use, or that can impart higher thermal conductivity with the amount of level of conventional use. That is.
Another object of the present invention is to provide a thermally conductive resin composition having high thermal conductivity, excellent film formability, and excellent substrate followability when deposited on a substrate. That is.
Another object of the present invention is to provide a heat conductive member having high heat conductivity.

The present invention relates to an aggregate obtained by aggregating non-spherical heat conductive particles with an organic binder, which is easily deformed with respect to pressure but hardly collapses.
That is, the present invention includes 100 parts by mass of non-spherical heat conductive particles (A) having an average primary particle size of 0.1 to 15 μm and 0.1 to 30 parts by mass of the organic binder (B), The present invention relates to an easily deformable aggregate (D) having a particle diameter of 2 to 100 μm and an average compressive force required for a compression deformation rate of 10% of 5 mN or less.

  The present invention also dissolves the above easily deformable aggregate (D) in an amount of 20 to 90% by volume based on the solid content, the binder resin (E) in an amount of 10 to 80% by volume based on the solid content, and the binder resin (E). It is related with the heat conductive resin composition (G) containing the solvent (F) to do.

The present invention also relates to a heat conductive member (H) including a heat conductive layer obtained by removing the solvent (F) from the above heat conductive resin composition (G).
The present invention also relates to a heat conductive member (I) formed by pressurizing the heat conductive member (H).

  The easily deformable agglomerates of the present invention can impart the same thermal conductivity to the heat conductive member with a smaller amount of use, or higher heat conductivity with the same amount of the conventional heat conductivity. It is a thermal conductivity imparting material that can be imparted to a member.

"Easily deformable aggregate (D)"
The easily deformable aggregate (D) of the present invention comprises 100 parts by mass of non-spherical heat conductive particles (A) having an average primary particle size of 0.1 to 15 μm and an organic binder (B) of 0.1 to 0.1 parts. 30 parts by mass, the average particle size is 2 to 100 μm, and the average compressive force required for a compression deformation rate of 10% is 5 mN or less.

The “easy deformability” in the present invention means that an average compressive force required for a compression deformation rate of 10% is 5 mN or less.
The “average compressive force required for a compression deformation rate of 10%” is an average value of a load for deforming particles by 10%, measured by a compression test. This can be measured, for example, with a micro compression tester (manufactured by Shimadzu Corporation, MCT-210).
Specifically, it can be measured as follows.
A very small amount of sample to be measured is magnified and observed with a microscope, an arbitrary particle is selected, this measured particle is moved to the lower part of the pressurized indenter, a load is applied to the pressurized indenter, and the measured particle is compressed. Deform. The tester includes a detector for measuring the compression displacement of the measurement target particle at the top of the pressurizing indenter. The detector measures the compression displacement of the particles to be measured, and obtains the deformation rate. Then, the compression force required for 10% compressive deformation of the particles to be measured (hereinafter also abbreviated as “10% compression deformation force”) is obtained. Similarly, “10% compressive deformation force” is obtained for any other particles to be measured, and the average value of “10% compressive deformation force” for 10 particles to be measured is “average required for 10% compression deformation rate”. Compressive force ".
The easily deformable aggregate (D) of the present invention is a state in which a plurality of small heat conductive particles (A) are aggregated as will be described later. The unit of

(Thermal conductive particles (A))
Thermally conductive particles (A) are not particularly limited as long as they have thermal conductivity,
For example,
Metal oxides such as aluminum oxide, calcium oxide, and magnesium oxide;
Metal nitrides such as aluminum nitride and boron nitride;
Metal hydroxides such as aluminum hydroxide and magnesium hydroxide;
Metal carbonates such as calcium carbonate and magnesium carbonate;
Metal silicates such as calcium silicate;
Hydrated metal compounds;
Crystalline silica, amorphous silica, silicon carbide, and composites thereof;
Metals such as gold and silver;
And carbon materials such as carbon black, graphene, carbon nanotube, and carbon fiber.
These may be used alone or in combination of two or more.

  When used in electronic material applications such as electronic circuits, the heat conductive particles (A) preferably have insulating properties, and metal oxides and metal nitrides are preferable, among which thermal conductivity and hydrolysis are preferred. Boron nitride is more preferable from the viewpoint of stability that it is difficult.

The shape of the heat conductive particles (A) is non-spherical.
In the present invention, “non-spherical” can be represented by “circularity”, for example. Here, the “circularity” can be expressed by the following equation when an arbitrary number of particles are selected from a photograph of the particles taken with an SEM, the area of the particles is S, and the circumference is L.
(Circularity) = 4πS / L ²
For the measurement of circularity, various image processing software or an apparatus equipped with image processing software can be used.
The “non-spherical particles” in the present invention have an average circularity of less than 0.9 when the average circularity of the particles is measured using a flow type particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics Co., Ltd. Say. Use of non-spherical heat conductive particles is preferable because the contact area between the particles increases, the efficiency of heat transfer between the heat conductive particles (A) increases, and the heat conductivity of the entire system can be improved. .

The non-spherical heat conductive particles (A) used for obtaining the easily deformable aggregate (D) have an average primary particle diameter of 0.1 to 15 μm, and preferably 0.3 to 13 μm. A plurality of types of thermally conductive particles (A) having different sizes can also be used.
If the average primary particle size is too small, the number of contacts between the primary particles in the aggregate increases, and the contact resistance increases, so the thermal conductivity tends to decrease. On the other hand, if the average primary particle size is too large, it tends to collapse even if an aggregate is prepared, and the aggregate itself is difficult to be formed.

In the present invention, “primary particles” represent the smallest particles that can exist alone, and “average primary particle size” means the major axis of the primary particle size observed with a scanning electron microscope. “Long diameter of primary particle diameter” means the maximum diameter of primary particles for spherical particles, and the maximum diameter or maximum diagonal line in the projected image of particles observed from the thickness direction for hexagonal or disk-like particles, respectively. Means long. Specifically, the “average primary particle size” is calculated as the number average of 300 major particles measured by the above method.
In addition, the fact that the easily deformable aggregate (D) of the present invention is “not easily disintegrated” means that, for example, the easily deformable aggregate (D) is placed in a glass sample tube so as to have a porosity of 70%. Even if shaken for 2 hours, the average particle size after shaking is 80% or more of the average particle size before shaking.

(Organic binder (B))
The organic binder (B) in the present invention plays a role of “tethering” for binding the heat conductive particles (A) to each other.
It does not restrict | limit especially as an organic binder (B), The molecular weight is not ask | required in the range which can play the role of a "tie".
As the organic binder (B), for example,
Surfactant, polyether resin, polyurethane resin, (unsaturated) polyester resin, alkyd resin, butyral resin, acetal resin, polyamide resin, (meth) acrylic resin, styrene / (meth) acrylic resin, polystyrene resin, nitrocellulose, Benzylcellulose, cellulose (tri) acetate, casein, shellac, gelatin, gilsonite, rosin, rosin ester, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, Carboxymethylcellulose, carboxymethylethylcellulose, carboxymethylnitrocell , Ethylene / vinyl alcohol resin, styrene / maleic anhydride resin, polybutadiene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinylidene fluoride resin, polyvinyl acetate resin, ethylene / vinyl acetate resin, vinyl chloride / vinyl acetate Resin, vinyl chloride / vinyl acetate / maleic acid resin, fluorine resin, silicone resin, epoxy resin, phenoxy resin, phenol resin, maleic acid resin, urea resin, melamine resin, benzoguanamine resin, ketone resin, petroleum resin, chlorinated polyolefin resin , Modified chlorinated polyolefin resin, and chlorinated polyurethane resin.
The organic binder (B) can use 1 type (s) or 2 or more types.

Since the organic binder (B) affects the deformability of the easily deformable aggregate (D) to be obtained, the organic binder (B) is preferably non-curable.
“Non-curing” means that the organic binder (B) does not self-crosslink at 25 ° C.
It is preferable not to use a component that functions as a curing agent for the organic binder (B).

When the heat conductive member (I) described later is an adhesive sheet, a water-soluble resin is suitable as the organic binder (B). Examples of the water-soluble resin include polyvinyl alcohol and polyvinyl pyrrolidone.
Depending on the application, a water-insoluble resin can be used as the organic binder (B). Examples of the water-insoluble resin include phenoxy resin and petroleum resin.

The easily deformable aggregate (D) of the present invention contains 0.1 to 30 parts by mass, preferably 1 to 10 parts by mass of the organic binder (B) with respect to 100 parts by mass of the heat conductive particles (A). To do.
If the amount of the organic binder (B) is less than 0.1 parts by mass, the heat conductive particles (A) cannot be sufficiently bound and sufficient strength cannot be obtained to maintain the form. It is not preferable. When the amount of the organic binder (B) is more than 30 parts by mass, the effect of binding the thermally conductive particles (A) is increased, but the organic binder is more than necessary between the thermally conductive particles (A). Since there is a possibility that the adhering agent (B) may enter and inhibit thermal conductivity, it is not preferable.

2-100 micrometers is preferable and, as for the average particle diameter of the easily deformable aggregate (D) of this invention, More preferably, it is 10-70 micrometers. When the average particle diameter of the easily deformable aggregate (D) is smaller than 2 μm, the number of the heat conductive particles (A) constituting the aggregate (D) is reduced, the effect as the aggregate is low, and the deformability is reduced. Is also not preferable. When the average particle diameter of the easily deformable aggregate (D) exceeds 100 μm, the mass of the easily deformable aggregate (D) per unit volume is increased, and there is a possibility of sedimentation when used as a dispersion. Absent.
The “average particle diameter” of the easily deformable aggregate (D) in the present invention is a value when measured with a particle size distribution meter (for example, Mastersizer 2000, manufactured by Malvern Instruments).

The specific surface area of the easily deformable aggregate (D) is not particularly limited, but is preferably 10 m ² / g or less, and more preferably 5 m ² / g or more. When it is larger than 10 m ² / g, the binder resin (E) described later tends to be adsorbed on the particle surface or the inside of the agglomerate, and the film formability and the adhesive force tend to be lowered.
"Specific surface area" is a value when measured with a BET specific surface area meter (for example, BELSORP-mini manufactured by Nippon Bell Co., Ltd.).

  The organic binder (B) can have a nitrogen atom. In this case, the non-covalent interaction between the nitrogen atom in the organic binder (B) and the skeleton of the binder resin (E) described later causes aggregation of the heat conductive members (H) and (I) described later. For example, when used as an adhesive sheet, the adhesive force is improved.

  The organic binder (B) having a nitrogen atom is not particularly limited, and in the various resins exemplified as the organic binder (B), a resin having one or more functional groups containing a nitrogen atom. Is mentioned.

  The organic binder (B) having a functional group containing a nitrogen atom may be a resin synthesized using a monomer having a functional group containing a nitrogen atom, or a resin not having a functional group containing a nitrogen atom May be modified by adding a functional group containing a nitrogen atom.

Examples of functional groups containing nitrogen atoms include:
Urethane group, thiourethane group, urea group, thiourea group, amide group, thioamide group, imide group, amino group, imino group, cyano group, hydrazino group, hydrazono group, hydrazo group, azino group, diazenyl group, azo group, ammonio Group, iminio group, diazonio group, diazo group, azide group, isocyanate group and the like.
Among these, a urethane group, an amide group, an amino group, and the like are preferable because the amount of nitrogen atom introduced can be easily controlled.

When the heat conductive member (I) described later is an adhesive sheet, a water-soluble resin is suitable as the organic binder (B). Examples of the water-soluble resin containing a nitrogen atom include polyethyleneimine, polyallylamine, polyacrylamide, and polyvinylpyrrolidone.
Depending on the application, a water-insoluble resin can be used as the organic binder (B). Examples of water-soluble resins containing nitrogen atoms include water-insoluble urethane resins and water-insoluble amide resins.

The organic binder (B) can have a reactive functional group.
In this case, the reaction of the reactive functional group in the organic binder (B) and the functional group in the binder resin (E), which will be described later, causes the heat conduction of the heat conductive members (H) and (I), which will be described later. The cross-linked structure in the layer develops, leading to improved heat resistance.
“Reactivity” as used herein refers to a functional group and a crosslinked structure of the binder resin (E) described later by heating the heat conductive member (H) and (I) described later including the aggregate (D) of the present invention. To form. In addition, it is preferable that a heating process is performed after the heat conductive members (H) and (I) described later are pressurized and the aggregate (D) is deformed or after the deformation. For example, if the functional group exhibits reactivity at a non-heating temperature such as 25 ° C. and exhibits reactivity before being compressed and deformed, the deformability of the easily deformable aggregate (D) is impaired.

  The organic binder (B) having a reactive functional group is not particularly limited, and in the various resins exemplified as the organic binder (B), a resin having one or more reactive functional groups. Is mentioned.

  The organic binder (B) having a reactive functional group may be a resin synthesized using a monomer having a reactive functional group, or a part of a resin having no reactive functional group may be modified. Further, a functional group having reactivity may be added.

Examples of reactive functional groups include epoxy groups, carboxyl groups, acetoacetyl groups, amino groups, imino groups, isocyanate groups, hydroxyl groups, and thiol groups.
From the viewpoint of heat resistance, the reactive functional group of the organic binder (B) is an epoxy group, an acetoacetyl group, an amino group, a hydroxyl group, or a carboxyl group, and the functional group in the binder resin (E) is an epoxy group, It is preferably a carboxyl group or a hydroxyl group.

  When the heat conductive member (I) described later is an adhesive sheet, a water-soluble resin is suitable as the organic binder (B). Examples of the water-soluble resin having a reactive functional group include carboxymethyl cellulose and polyallylamine.

(Thermal conductive fiber (P))
The easily deformable aggregate (D) can contain a heat conductive fiber (P). In this case, the thermal conductivity of the easily deformable aggregate (D) can be improved.

The heat conductive fiber (P) is not particularly limited as long as it is a fibrous material having good heat conductivity. It is preferable that at least the surface of the heat conductive fiber (P) is a metal.

As the heat conductive fiber (P), for example, metal (nano) wires, metal (nano) tubes, metal meshes, and the like containing metals such as copper, platinum, gold, silver, and nickel are used.
The “fibrous substance” as used herein refers to a substance having an average length (aspect ratio) of 5 or more with respect to an average fiber diameter.
For example, the heat conductive fiber has a diameter of 0.3 to 50000 nm and a length of 1 to 5000 μm.

  Examples of the metal fiber synthesis method include a casting method (Japanese Patent Laid-Open No. 2004-269987), an electron beam irradiation method (Japanese Patent Laid-Open No. 2002-67000), and a chemical reduction method (Japanese Patent Laid-Open No. 2007-146279, Chemical Physics Letters 380). (2003) 146-169).

As the heat conductive fiber (P),
(Nano) wires, (nano) tubes, or (nano) fibers based on silicon, metal oxides, metal nitrides, or carbon;
and,
Sheet-like fibrils made of graphite or graphene can also be used.
As used herein, “nanowire, nanotube, nanofiber” refers to those having an average fiber diameter of less than 1 μm.

  As the heat conductive fiber (P), the non-heat conductive fiber is made of a material mainly composed of metal such as copper, platinum, gold, silver, and nickel, silicon, metal oxide, metal nitride, or carbon. A coated material can also be used. Examples of the coating method include electroplating, electroless plating, hot dip galvanizing, and vacuum deposition.

  Among the heat conductive fibers (P), a (nano) wire containing a metal as a main component is preferable from the viewpoint of easy deformability, and a metal (nano) wire containing silver as a main component from the point of oxidation resistance (silver Nano) wires) are particularly preferred.

  The addition amount of the thermally conductive fiber (P) used for obtaining the easily deformable aggregate (D) is preferably 0.01 to 50 parts by mass with respect to 100 parts by mass of the thermally conductive particles (A). Preferably it is 0.1-10 mass parts. If the amount added is greater than 50 parts by mass, the heat conductive fibers (P) that are not included in the easily deformable aggregate (D) may increase.

  The easily deformable aggregate (D) can contain a fibrous carbon material (J) as a thermally conductive fiber (P) (however, excluding carbon particles having an average primary particle size of 0.1 to 10 μm). . In this case, the thermal conductivity of the easily deformable aggregate (D) can be improved.

The fibrous carbon material (J) has a function of assisting heat conduction between the heat conductive particles (A).
Preferably, the non-spherical heat conductive particles (A) or the heat conductive particles (A) having a small particle diameter can be used to reduce voids in the aggregate (D). Furthermore, the thermal conductivity is further improved by using the fibrous carbon material (J) together to assist the heat conduction between the heat conductive particles (A).
The fibrous carbon material (J) is preferably smaller than the heat conductive particles (A) used.

  Examples of the fibrous carbon material (J) include carbon fibers, graphite fibers, vapor grown carbon fibers, carbon nanofibers, and carbon nanotubes. These can use 1 type (s) or 2 or more types.

The fibrous carbon material (J) is preferable because a heat conduction path can be efficiently formed between the heat conductive particles (A).
The carbon material (J) preferably has an average fiber diameter of 5 to 30 nm and an average fiber length of 0.1 to 20 μm.

  The easily deformable aggregate (D) of the present invention preferably contains 0.5 to 10 parts by mass of the fibrous carbon material (J) with respect to 100 parts by mass of the heat conductive particles (A). It is more preferable to contain 5 parts by mass. Within the above range, a heat conduction path can be formed while maintaining insulation.

  In the easily deformable aggregate (D), non-spherical particles not containing a carbon material and a carbon material having an arbitrary shape other than a fibrous material can be used in combination as the heat conductive particles (A). In this case, the thermal conductivity of the easily deformable aggregate (D) can be improved.

The carbon material having any shape other than the fibrous shape has a function of assisting heat conduction between non-spherical particles not including the carbon material.
Preferably, the non-spherical heat conductive particles (A) or the heat conductive particles (A) having a small particle diameter can be used to reduce voids in the aggregate (D). Furthermore, a thermal conductivity is further improved by using a carbon material together as the thermally conductive particles (A) and assisting thermal conduction between the thermally conductive particles (A) not containing the carbon material.
The carbon material having an arbitrary shape other than the fibrous shape is preferably smaller than non-spherical particles not containing the carbon material.

  Examples of carbon materials other than fibrous materials include graphite, carbon black, fullerene, and graphene. These can use 1 type (s) or 2 or more types.

In particular, a plate-like carbon material is preferable because a heat conduction path can be efficiently formed between non-spherical particles not containing the carbon material.
The plate-like carbon material preferably has an average aspect ratio of 10 to 3000 and an average thickness of 0.1 to 500 nm.

  The easily deformable aggregate (D) of the present invention can contain other optional components other than those described above, if necessary.

(Production method)
The easily deformable aggregate (D) of the present invention includes, for example, heat conductive particles (A), an organic binder (B), optional components added as necessary, and a solvent for dissolving or dispersing these components. A slurry containing (C) can be obtained, and then obtained by the method (1) in which the solvent (C) is removed from the slurry.
The easily deformable aggregate (D) of the present invention is simply the above components excluding the solvent (C) (thermally conductive particles (A), organic binder (B), and optional components added as necessary). ) Can also be obtained by the method (2) of mixing.
The easily deformable aggregate (D) of the present invention comprises a thermally conductive particle (A), an organic binder (B), an optional component added as necessary, and a solvent for dissolving or dispersing these components ( It can also be obtained by the method (3) of removing the solvent (C) after or while spraying a liquid (solution or dispersion) containing C).
In order to obtain the easily deformable aggregate (D) having a more uniform composition, the above method (1) is preferable.

The solvent (C) disperses the heat conductive particles (A) and dissolves the organic binder (B). When using the heat conductive fiber (P) and / or the carbon material (J), the solvent (C) disperses them.
The solvent (C) is not particularly limited as long as it can dissolve the organic binder (B), and can be appropriately selected depending on the type of the organic binder (B).
As the solvent (C), for example, ester solvents, ketone solvents, glycol ether solvents, aliphatic solvents, aromatic solvents, alcohol solvents, ether solvents, water, and the like can be used.
1 type (s) or 2 or more types can be used for a solvent (C).

The solvent (C) preferably has a lower boiling point from the viewpoint of ease of removal, and preferably has a boiling point of 110 ° C. or lower, such as water, ethanol, methanol, and ethyl acetate.
The amount of the solvent (C) used is preferably small from the viewpoint of easy removal, but can be appropriately changed according to the solubility of the organic binder (B) or the apparatus for drying the solvent.

  The method for removing the solvent (C) from the slurry is not particularly limited, and a commercially available apparatus can be used. For example, it can be selected from methods such as spray drying, stirring drying, and stationary drying. Above all, sprayable particles can be easily sprayed from the viewpoint that a readily deformable aggregate (D) having a relatively round particle size can be obtained with high productivity, and a fast drying speed and a deformable easily deformable aggregate (D) can be obtained. Drying can be suitably used. In this case, the solvent (C) may be volatilized and removed while spraying the slurry in the form of a mist. Spray conditions and volatilization conditions can be selected as appropriate.

"Thermal conductive resin composition (G), thermal conductive member (H), (I)"
The thermally conductive resin composition (G) of the present invention comprises 20 to 90% by volume of the easily deformable aggregate (D) of the present invention, 10 to 80% by volume of a binder resin (E), and a binder resin (E The solvent (F) which melt | dissolves).

A thermally conductive resin composition (G) is applied onto a substrate to form a coating film, and the solvent (F) is removed from the coating film to form a thermally conductive layer. H) can be obtained.
Furthermore, the heat conductivity which improved the heat conductivity of the heat conductive member (H) by applying a pressure to the heat conductive member (H), and deforming the easily deformable aggregate (D) contained. A member (high thermal conductivity member) (I) can be obtained.

For example, using the thermally conductive resin composition (G) to obtain a thermally conductive sheet as the thermally conductive member (H), and applying pressure by sandwiching the thermally conductive sheet between the object to be radiated and the heat radiating member Thus, a thermally conductive sheet with improved thermal conductivity can be obtained as the thermally conductive member (I). This heat conductive sheet can efficiently transmit the heat of the object to be radiated to the heat radiating member.
As the heat conductive member (H), a heat conductive sheet having adhesiveness or tackiness can be obtained. In this case, the article to be radiated and the radiating member can be bonded together at the time of pressurization.

  By applying pressure and heat to the thermally conductive resin composition (G) and deforming the easily deformable aggregate (D) contained therein, the sheet-like thermally conductive member (I) can be obtained directly. it can.

The heat conductive member (I) can also be obtained directly by applying pressure to the easily deformable aggregate (D) itself to deform the easily deformable aggregate (D). In this case, the organic binder (B) constituting the easily deformable aggregate (D) also serves as the binder resin (E).
For example, by sandwiching the easily deformable aggregate (D) between the heat dissipation target article and the heat dissipation member and applying pressure to deform the easily deformable aggregate (D), the heat of the heat dissipation target article is efficiently increased. It can be transmitted well to the heat dissipation member.

As an article for heat dissipation,
Various electronic components such as integrated circuits, IC chips, hybrid packages, multi-modules, power transistors and LED (light emitting diode) substrates;
Examples include articles that are used in building materials, vehicles, aircraft, ships, and the like, are easily heated, and need to release the heat to the outside in order to prevent performance deterioration.

In order to achieve high thermal conductivity, it is important to form more heat conduction paths in the direction in which heat is to be transmitted.
In the easily deformable aggregate (D) of the present invention, since the heat conductive particles (A) are aggregated, the distance between the particles is close and the heat conduction path is formed in advance, so that the heat conduction is efficiently performed. be able to.
In addition, since the easily deformable aggregate (D) of the present invention is “easy to deform”, high thermal conductivity can be realized. That is, when a force is applied to the easily deformable aggregate (D), the easily deformable aggregate (D) does not collapse, and the heat conductive particles (A) in the easily deformable aggregate (D) are not separated. By improving the adhesion, a previously formed heat conduction path can be enhanced. In addition, since the position of the thermally conductive particles (A) constituting the easily deformable aggregate (D) can be easily changed, the easily deformable aggregate (D) is formed between the heat radiation target article and the heat dissipation member. Follows the shape of the interface, the contact area between the heat radiation target article or heat radiating member and the heat conductive particles (A) increases, and the heat inflow area and the heat propagation path can be dramatically increased.
Thus, since the easily deformable aggregate (D) of the present invention is “easy to deform”, it has excellent thermal conductivity. That is, the easily deformable aggregate (D) of the present invention imparts the same thermal conductivity to the heat conductive member with a smaller amount of use, or higher heat with the same amount of the conventional one. Conductivity can be imparted to the thermally conductive member.

The thermal conductivity (W / m · K) is the thermal diffusivity (mm ² / s) representing the rate at which heat is conducted through the sample, and the specific heat capacity (J / (g · K)) and density (g / cm ³ ) and obtained by the following formula.
Thermal conductivity (W / m · K) = thermal diffusivity (mm ² / s) × specific heat capacity (J / (g · K)) × density (g / cm ³ )

  For the measurement of the thermal diffusivity, for example, a periodic heating method, a hot disk method, a temperature wave analysis method, a flash method, or the like can be selected according to the shape of the measurement sample. In the data described in this specification, the thermal diffusivity was measured by a flash method using a Xenon flash analyzer LFA447 NanoFlash (manufactured by NETZSCH).

As binder resin (E) used when obtaining a heat conductive resin composition, for example,
Polyurethane resin, polyester resin, polyester urethane resin, alkyd resin, butyral resin, acetal resin, polyamide resin, acrylic resin, styrene-acrylic resin, styrene resin, nitrocellulose, benzylcellulose, cellulose (tri) acetate, casein, shellac, gilsonite , Gelatin, styrene-maleic anhydride resin, polybutadiene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinylidene fluoride resin, polyvinyl acetate resin, ethylene vinyl acetate resin, vinyl chloride / vinyl acetate copolymer resin, vinyl chloride / Vinyl acetate / maleic acid copolymer resin, fluorine resin, silicone resin, epoxy resin, phenoxy resin, phenol resin, maleic acid resin, urea resin, melamine resin, benzoguanami Resin, ketone resin, petroleum resin, rosin, rosin ester, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, carboxymethylethylcellulose, carboxymethyl Examples thereof include nitrocellulose, ethylene / vinyl alcohol resin, polyolefin resin, chlorinated polyolefin resin, modified chlorinated polyolefin resin, and chlorinated polyurethane resin.
Binder resin (E) can use 1 type (s) or 2 or more types.
Among these, urethane resins are preferably used from the viewpoint of flexibility, and epoxy resins are preferably used from the viewpoint of insulation and heat resistance when used as an electronic component.
In addition, it is preferable that the organic binder (B) which comprises an easily deformable aggregate (D) is non-curable in order to ensure easy deformability. On the other hand, as the binder resin (E), the binder resin (E) itself can be cured or can be cured by reaction with an appropriate curing agent.

When the organic binder (B) has a reactive functional group, the binder resin (E) preferably has a functional group that reacts with the reactive functional group of the organic binder (B).
Examples of the functional group of the binder resin (E) include an epoxy group, a carboxyl group, an acetoacetyl group, an ester group, an amino group, an imino group, an isocyanate group, a hydroxyl group, and a thiol group. The binder resin (E) can have one type or two or more types of functional groups.

A heat conductive resin composition (G) contains an easily deformable aggregate (D), binder resin (E), and a solvent (F). The solvent (F) used is used for uniformly dispersing the easily deformable aggregate (D) and the binder resin (E) in the thermally conductive resin composition (G).
As the easily deformable aggregate (D), one kind may be used alone, the average particle diameter, the kind of the heat conductive particles (A) or the average primary particle diameter, or the organic binder (B). Different types or amounts may be used in combination.

It is important to appropriately select the solvent (F) that can dissolve the binder resin (E) and does not dissolve the organic binder (B) constituting the easily deformable aggregate (D). is there. When the heat conductive resin composition (G) is obtained, if the solvent (F) that dissolves the organic binder (B) is used, the aggregation state of the easily deformable aggregate (D) cannot be maintained.
For example, when a water-soluble resin such as polyvinyl alcohol or polyvinyl pyrrolidone is selected as the organic binder (B), the solvent (F) for obtaining the heat conductive resin composition (G) may be toluene or xylene. A non-aqueous solvent may be selected.
When a water-insoluble resin such as phenoxy resin or petroleum resin is selected as the organic binder (B), the solvent (F) for obtaining the thermally conductive resin composition (G) is water or an aqueous solution such as alcohol. A solvent may be selected.
As used herein, “insoluble” means that 1 g of the organic binder (B) is added to 100 g of the solvent (F), stirred at 25 ° C. for 24 hours, and precipitation is confirmed visually.

At this time, content of easily deformable aggregate (D) can be suitably selected according to the target heat conductivity and a use. In order to obtain high thermal conductivity, the content of the easily deformable aggregate (D) is preferably 20 to 90% by volume based on the solid content of the thermal conductive resin composition (G). It is preferable that it is -80 volume%.
If the content is less than 20% by volume, the effect of adding the easily deformable aggregate (D) is thin and sufficient thermal conductivity cannot be obtained. On the other hand, when it exceeds 90% by volume, the content of the binder resin (E) is relatively reduced, and the formed heat conductive members (H) and (I) become brittle, or the heat conductive member (I) There is a possibility that voids may be formed in the surface, and there is a possibility that the thermal conductivity is gradually lowered while using the thermal conductive member (I).
The “volume%” as used herein refers to the heat conductive particles (A), the organic binder (B), and optional components blended as necessary with respect to the solid content in the heat conductive resin composition (G). The theoretical value calculated based on the mass ratio of the thermally conductive fiber (P) and / or the carbon material (J), etc., and the binder resin (E) and the specific gravity of each component is shown.

The heat conductive resin composition (G) can be used in combination with heat conductive particles that are not aggregated. By also using non-aggregated thermally conductive particles, the gap between the easily deformable aggregates (D) is filled, or when a gap is generated when the easily deformable aggregates (D) are deformed, the heat conduction A further improvement effect of thermal conductivity can be expected by filling the gaps between the conductive particles (A).
Examples of the thermally conductive particles that can be used in combination include those exemplified as the thermally conductive particles (A).

The heat conductive resin composition (G) may further contain a flame retardant and / or a filler as necessary.
Examples of the flame retardant include aluminum hydroxide and magnesium hydroxide.

Various other additives can be added to the heat conductive resin composition (G) as necessary. Examples of the additive include a coupling agent for increasing the adhesion to the substrate, an ion scavenger for increasing the insulation reliability at the time of moisture absorption, and a leveling agent.
When the organic binder (B) has a reactive functional group and the binder resin (E) has a functional group that reacts with the reactive functional group of the organic binder (B), a thermally conductive resin composition ( A curing agent for enhancing heat resistance can be added to G). Heat resistance can be improved by making an organic binder (B) react not only with binder resin (E) but with a hardening | curing agent.
One or more additives can be used.

A heat conductive resin composition (G) can be manufactured by stirring and mixing an easily deformable aggregate (D), a binder resin (E), a solvent (F), and other optional components as necessary. it can.
A general stirring method can be used for stirring and mixing. Examples of the stirring mixer include a disper, a scandex, a paint conditioner, a sand mill, a raking machine, a medialess disperser, a three roll, a bead mill, and the like.

  After stirring and mixing, it is preferable to go through a defoaming step in order to remove bubbles from the heat conductive resin composition (G). Examples of the defoaming method include vacuum defoaming and ultrasonic defoaming.

The manufacturing method of the heat conductive member (H) of the present invention is:
Applying a thermally conductive resin composition (G) on a substrate to form a coating film;
Removing the solvent (F) from the coating film to form a heat conductive layer.

The method for producing the heat conductive member (I) of the present invention comprises:
Preparing a thermally conductive member (H);
And pressurizing the heat conductive layer.

  As the heat conductive members (H) and (I), a heat conductive sheet or the like can be manufactured. A heat conductive sheet may be called a heat conductive film.

Examples of the substrate include plastic films such as polyester film, polyethylene film, polypropylene film, and polyimide film;
and,
A film obtained by releasing the plastic film (hereinafter referred to as a release film);
Examples thereof include metal bodies or metal foils such as aluminum, copper, stainless steel, and beryllium copper.

  Examples of the method for applying the thermally conductive resin composition (G) to the substrate include knife coating, die coating, lip coating, roll coating, curtain coating, bar coating, gravure coating, flexographic coating, dip coating, spray coating, and screen. Examples thereof include a coat, a dispenser, an ink jet and a spin coat.

The thickness of the heat conductive layer can be appropriately determined according to the application.
In applications such as a heat conductive sheet, which is disposed between a heat source and a heat sink and used to release heat, the thickness of the heat conductive layer is usually 10 to 200 μm from the viewpoint of heat conductivity and various physical properties, The thickness is preferably 30 to 150 μm. In addition, in applications such as a housing such as a package in which heat from a heat source is not trapped, the thickness of the heat conductive layer can be set to 200 μm or more, and in some cases, about 1 mm in view of strength and the like. .

  Moreover, in order to reinforce adhesiveness with a member to be cooled, a strong adhesive layer may be provided on both surfaces of the heat conductive member of the present invention, and used as a three-layer laminate.

In the heat conductive member (H), the contact resistance between the easily deformable aggregates (D) is preferably as small as possible in order to improve the heat conductivity.
By selecting the easily deformable aggregate (D) having an appropriate size with respect to the thickness of the heat conductive member (H), the total contact resistance in the heat conductive member (H) can be reduced. .
Specifically, the ratio of the average particle diameter of the easily deformable aggregate (D) to the thickness of the heat conductive member (H) is preferably 20% or more, and more preferably 50% or more.
The ratio of the average particle diameter of the easily deformable aggregate (D) to the thickness of the heat conductive member (H) may be 100% or more. In this case, the heat conductive member (I) is formed by sandwiching the heat conductive member (H) between the heat dissipation object and the heat dissipation member, applying pressure, and deforming the easily deformable aggregate (D). A heat conduction path that penetrates can be formed.

  When it is desired to obtain a thick heat conductive member (H) according to the application, it is possible to efficiently form a heat conduction path by laminating a plurality of heat conductive members (H) having the above ratio of 20% or more. is there.

After the heat conductive layer (H) is manufactured by forming a heat conductive layer on an arbitrary base material, another arbitrary base material is stacked, and press-pressed under heating, and the heat conductive member (I) is Can be obtained.
At least one of the two substrates can be a release film. In this case, the release film can be peeled off.
When two base materials are used as release films, the two release films are peeled off to isolate the heat conductive layer, which can be used as the heat conductive member (I).

The pressure press processing method is not particularly limited, and a known press processing machine can be used.
Although the temperature at the time of pressurization can be selected suitably, if it uses as a thermosetting adhesive sheet, it is desirable to heat above the temperature which the thermosetting of binder resin (E) occurs.
If necessary, it can be pressed under reduced pressure.
The pressure at the time of pressing can be appropriately selected as long as a pressure capable of deforming the easily deformable aggregate (D) can be applied, but is preferably 1 MPa or more.

  By directly molding the heat conductive resin composition (G) containing no solvent (F) under pressure, a highly heat-conductive molded product can be obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, a following example does not restrict | limit the right range of this invention at all. In Examples, “parts” and “%” represent “parts by mass” and “mass%”, “vol%” represents “volume%”, and Mw represents a mass average molecular weight, unless otherwise specified. Represent.

  Average primary particle diameter of thermally conductive particles (A), average particle diameter of easily deformable aggregates (D), circularity of thermally conductive particles (A), compressive deformation ratio of easily deformable aggregates (D) 10 %, Compressibility of easily deformable aggregate (D) (retention rate of average particle diameter after shaking test), shape of carbon material (J), heat conductive member (H), The thermal conductivity of (I), the adhesive strength of the thermal conductive member (I) (adhesive sheet), and the heat resistance of the thermal conductive member (I) were determined as follows.

<Average primary particle size>
The major axis of particles having a primary particle size of 300 observed with a scanning electron microscope was measured, and the number average was determined.
In the case of spherical particles, the “major primary particle diameter” is the maximum primary particle diameter,
In the case of hexagonal plate-like or disk-like particles, “major diameter of primary particle diameter” means the maximum diameter or the maximum diagonal length in the projected image of the particles observed from the thickness direction, respectively.

<Average particle size>
It measured using the particle size distribution meter master sizer 2000 by Malvern Instruments. A dry unit was used. The air pressure was 2.5 bar. The feed rate was optimized by the sample.

<Circularity>
The average circularity was measured using a flow type particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics Co., Ltd. About 5 mg of particles to be measured were dispersed in 10 ml of toluene to prepare a dispersion, and the dispersion was irradiated with ultrasonic waves (20 kHz, 50 W) for 5 minutes to adjust the dispersion concentration to 5,000 to 20,000 particles / μl. Using this dispersion, measurement was carried out with the above-mentioned apparatus, the circularity of the equivalent-circle diameter particle group was measured, and the average circularity was determined.

<Average compression force required for 10% compression deformation>
Using a micro compression tester (manufactured by Shimadzu Corporation, MCT-210), a load for deforming the particles by 10% was measured for 10 particles randomly selected in the measurement region. The average value was defined as the average compression force required for a compression deformation rate of 10%.

<Difficult to disintegrate (retention rate of average particle diameter after shaking test)>
The easily deformable aggregate (D) was put in a glass sample tube so that the porosity was 70%, and after shaking for 2 hours with a shaker, the particle size distribution was measured. As a maintenance ratio of the average particle diameter after the shaking test, a ratio of the average particle diameter after the treatment to the average particle diameter before the treatment was obtained.
The case where the average particle diameter after the treatment was 80% or more of the average particle diameter before the treatment was determined as “hard to disintegrate”.

<Thermal conductivity>
A sample sample was cut into a 15 mm square, gold was deposited on the sample surface, coated with carbon by carbon spray, and then the thermal diffusivity at 25 ° C. in the sample environment was measured with a xenon flash analyzer LFA447 NanoFlash (NETZSCH). . The specific heat capacity was measured using a high-sensitivity differential scanning calorimeter DSC220C manufactured by SII Nano Technology. The density was calculated using an underwater substitution method. From these parameters, the thermal conductivity was determined.

<Heat resistance>
Thermally conductive member (I) (adhesive sheet) (3-layer sample: Cu foil (40 μm thickness) / thermal conductive layer / aluminum plate (250 μm thickness)) on the molten solder at 260 ° C., the aluminum plate surface Float for 3 minutes after contact. Then, the external appearance of the sample was visually observed to evaluate the state of occurrence of foaming and floating / peeling of the heat conductive member (I).
“Foaming” is a state in which bubbles are generated at the interface between the heat conductive layer and the Cu foil (40 μm).
“Floating / peeling” is a state in which the heat conductive layer is lifted off the aluminum plate and peeled off.
The evaluation criteria are as follows.
Excellent (◎): No change in appearance,
Good (○): Small foaming is slightly observed,
Possible (△): Foaming is observed,
Impossible (x): generation of severe foaming or floating / peeling is observed.

Abbreviations in the table are shown below.
H ₂ O: ion exchange water,
Tol: Toluene
IPA: 2-propanol
MEK: methyl ethyl ketone.

<Resin synthesis example 1>
Polyester polyol obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube (Corporation) “Kuraray polyol P-1011” manufactured by Kuraray, Mn = 1006) 401.9 parts by mass, 12.7 parts by mass of dimethylolbutanoic acid, 151.0 parts by mass of isophorone diisocyanate, and 40 parts by mass of toluene were charged under a nitrogen atmosphere. It was made to react at 3 degreeC, 300 mass parts of toluene was added to this, and the urethane prepolymer solution which has an isocyanate group was obtained.
Next, 27.8 parts by mass of isophorone diamine, 3.2 parts by mass of di-n-butylamine, 342.0 parts by mass of 2-propanol, and 396.0 parts by mass of toluene have the obtained isocyanate group. 815.1 parts by mass of a urethane prepolymer solution was added, reacted at 70 ° C. for 3 hours, diluted with 144.0 parts by mass of toluene and 72.0 parts by mass of 2-propanol, Mw = 54,000, acid value = 8 mgKOH / g of polyurethane polyurea resin (E-1) was obtained.

<Resin synthesis example 2>
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, dropping device, introduction tube, and nitrogen introduction tube, 292.1 parts by mass of polycarbonate diol (Kuraray polyol C-2090: manufactured by Kuraray Co., Ltd.), tetrahydroanhydrophthalic acid 44.9 parts by mass of acid (Licacid TH: manufactured by Shin Nippon Rika Co., Ltd.) and 350.0 parts by mass of toluene as a solvent were charged, and the mixture was heated to 60 ° C. with stirring in a nitrogen stream and dissolved uniformly. . Subsequently, the flask was heated to 110 ° C. and reacted for 3 hours. Then, after cooling to 40 ° C., 62.9 parts by mass of a bisphenol A type epoxy resin (YD-8125: manufactured by Toto Kasei Co., Ltd.) and 4.0 parts by mass of triphenylphosphine as a catalyst were added, and the temperature was raised to 110 ° C. And allowed to react for 8 hours. After cooling to room temperature, the solid content was adjusted to 35% with toluene to obtain a solution of carboxyl group-containing modified ester resin (E-2) having Mw = 25000.

<Resin synthesis example 3>
A 4-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel was charged with 98.5 parts by mass of butyl acrylate, 1.5 parts by mass of acrylic acid, and 150.0 parts by mass of ethyl acetate. The mixture was heated to 70 ° C. under nitrogen substitution, and 0.15 parts by mass of azobisisobutyronitrile was added to initiate polymerization. 0.13 parts by mass of azobisisobutyronitrile was added from 3 hours to 5 hours after every 1 hour after the start of polymerization, and the polymerization was further carried out for 2 hours. Thereafter, 150.0 parts by mass of ethyl acetate was added to terminate the polymerization, and a solution of an acrylic resin (E-3) having a solid content of 25% and Mw = 84000 was obtained.

(Fiber synthesis example 1: Silver nanowire)
To 100 ml of ethylene glycol heated to 160 ° C., 10 ml of an ethylene glycol solution of 0.15 mM silver nitrate was added over 10 seconds. Ten minutes later, the temperature was raised to 170 ° C., and 200 ml of 100 mM silver nitrate ethylene glycol solution and 200 ml of 600 mM polyvinyl pyrrolidone (Mw 40000) ethylene glycol solution were added over 210 minutes. Furthermore, it heated at 170 degreeC for 3 hours.
Subsequently, the resulting solution was reprecipitated three times with isopropanol, whereby about 0.3 mass of silver nanowires having an average fiber diameter of 500 nm and an average length of 10 μm (aspect ratio of 20) having a silver content of 3.0 mg / ml was obtained. %, A dispersion liquid (P1) dispersed in isopropanol was obtained.

(Fiber synthesis example 2: copper wire)
Sodium borohydride aqueous solution in which sodium borohydride and distilled water are mixed so as to be 5.0 mol / l as a metal ion reducing agent, and 0.2 ml of copper acetate dissolved in 10 ml of distilled water 100 ml was prepared. To a sodium borohydride aqueous solution, 0.5 g of a water-soluble polymer polyvinyl pyrrolidone (PVP) was added and dissolved by stirring.
Subsequently, a mixed gas adjusted to have a nitrogen to oxygen ratio of 3: 1 was bubbled into the reducing aqueous solution for about 60 minutes, and then the water temperature was set to 20 ° C. and 10 ml of the aqueous copper acetate solution was added dropwise. The mixture was stirred well for about 60 minutes while maintaining the water temperature at 20 ° C. The produced black reaction liquid was recovered, and a dispersion liquid (P2) in which about 0.18% by mass of copper wire having an average fiber diameter of 12 μm and an average length of 100 μm (aspect ratio 8.3) with a copper content of 1.8 mg / ml was dispersed. )

(Fiber synthesis example 3: Metal-coated polymer nanofiber)
Using a copolymer of acrylonitrile / glycidyl methacrylate = 35/65 (Mw = 40,000), 70 parts by mass of polymer nanofibers were produced by electrospinning. Further, this and 200 mL of hydrazinium hydroxide were mixed in a 2500 mL flask and stirred overnight. Then, after washing 6 times with 5000 mL of methanol, it was dried in vacuum at 50 ° C. for 24 hours.
By immersing 70 parts by weight of hydrazine modified polymer nanofibers in a mixture of 50 mL of 0.1 M AgNO ₃ solution, 5 mL of 1 M KOH solution and 10 mL of concentrated NH ₃ solution in a sealed glass bottle, went. Further, after washing with 5000 mL of methanol 6 times, the polymer nanofiber (P3) coated with silver having an average fiber diameter of 100 nm and an average length of 15 μm (aspect ratio 150) is obtained by drying at 50 ° C. for 24 hours in a vacuum. It was.

Example 1
Boron nitride particles as thermal conductive particles (A) (“NX-1” manufactured by Momentive Performance Materials Japan, average primary particle size: 0.7 μm, circularity: 0.6) 100 parts by mass, organic As a binder (B), a 4% by weight aqueous solution of polyvinyl alcohol (“GOHSENOL NL-05” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.): 25 parts by mass (solid content: 1 part by mass), and thermally conductive particles in the slurry (A) Ion-exchanged water as solvent (C): 125 parts by mass was stirred with a disper at 1000 rpm for 1 hour so that the concentration was 40% by weight to obtain a slurry. This slurry is spray-dried in a mini-spray dryer (“B-290” manufactured by Nihon Büch) in an atmosphere of 125 ° C., and the average compression force required for an average particle size of about 15 μm and a compression deformation rate of 10%: about 0.3 mN The retention rate of the average particle diameter after the shaking test: 85% easily deformable aggregate (D-1) was obtained.

(Example 2)
Except that the 4% by weight aqueous solution of polyvinyl alcohol that was 25 parts by mass (solid content: 1 part by mass) was 50 parts by mass (solid content: 2 parts by mass) and the ion-exchanged water that was 125 parts by mass was 100 parts by mass. In the same manner as in Example 1, an easily deformable aggregate (D) having an average particle diameter of about 5 μm, an average compression force required for a compression deformation ratio of 10%: about 1 mN, and an average particle diameter maintenance ratio after a shaking test of 85% -2) was obtained.

(Example 3)
The 4 mass% polyvinyl alcohol solution which was 25 mass parts (solid content: 1 mass part) was 125 mass parts (solid content: 5 mass parts), and the ion-exchange water which was 125 mass parts was 25 mass parts. In the same manner as in Example 1, an easily deformable aggregate having an average particle size of about 10 μm, an average compression force required for a compression deformation rate of 10%: about 1.5 mN, and an average particle size maintenance rate after a shaking test of 95% (D-3) was obtained.

Example 4
Boron nitride particles as thermal conductive particles (A) (“NX-5” manufactured by Momentive Performance Materials Japan Co., Ltd., average primary particle size: 5 μm, circularity: 0.55) 100 parts by mass, the polyvinyl alcohol An average particle diameter of about 25 μm was obtained in the same manner as in Example 1 except that 8% by weight aqueous solution of “GOHSENOL NL-05”: 125 parts by mass (solid content: 10 parts by mass) and ion-exchanged water: 25 parts by mass were used. Further, an easily deformable aggregate (D-4) having an average compression force required for a compression deformation rate of 10%: about 3 mN and an average particle diameter maintenance rate after a shaking test of 87% was obtained.

(Example 5)
Boron nitride particles (“PT160” manufactured by Momentive Performance Materials Japan Co., Ltd., average primary particle size: 8 μm, circularity: 0.25) 100 parts by mass as the thermally conductive particles (A), the polyvinyl alcohol “Gosenol” NL-05 "4 mass% aqueous solution: 50 parts by mass (solid content: 2 parts by mass) and ion-exchanged water: 100 parts by mass In the same manner as in Example 1, the average particle size was about 30 µm, compression An easily deformable aggregate (D-5) having an average compressive force required for a deformation rate of 10%: about 2.4 mN and an average particle size retention rate after a shaking test of 85% was obtained.

(Example 6)
Boron nitride particles as thermal conductive particles (A) (“PT140” manufactured by Momentive Performance Materials Japan Co., Ltd., average primary particle size: 10 μm, circularity: 0.4) 100 parts by mass, the polyvinyl alcohol “Gosenol NL-05 "20% by mass aqueous solution: 120 parts by mass (solid content: 30 parts by mass) and ion-exchanged water: 30 parts by mass In the same manner as in Example 1, an average particle size of about 50 µm, compression An easily deformable aggregate (D-6) having an average compressive force required for a deformation rate of 10%: about 3.2 mN and an average particle size maintenance rate after a shaking test of 88% was obtained.

(Example 7)
Boron nitride particles as thermal conductive particles (A) (“PT120” manufactured by Momentive Performance Materials Japan Co., Ltd., average primary particle size: 13 μm, circularity: 0.47) 100 parts by mass, the polyvinyl alcohol “GOHSENOL” NL-05 "4 mass% aqueous solution: 50 parts by mass (solid content: 2 parts by mass) and ion-exchanged water: 100 parts by mass In the same manner as in Example 1, the average particle size was about 100 µm, and compression An easily deformable aggregate (D-7) having an average compressive force required for a deformation rate of 10%: about 0.8 mN and an average particle size retention rate after a shaking test of 82% was obtained.

(Example 8)
Boron nitride particles (“PT140” manufactured by Momentive Performance Materials Japan, average primary particle size: 10 μm, circularity: 0.4) 100 parts by mass as the thermally conductive particles (A), an organic binder ( Example 4 except that 4 mass% aqueous solution of polyvinylpyrrolidone (“K-85W” manufactured by Nippon Shokubai Co., Ltd.): 125 mass parts (solid content: 5 mass parts) and ion-exchanged water: 25 mass parts were used as B). 1, an easily deformable aggregate (D) having an average particle diameter of about 20 μm, an average compression force required for a compression deformation ratio of 10%: about 1.2 mN, and an average particle diameter maintenance ratio after a shaking test of 90% -8) was obtained.

Example 9
Modified with an acetoacetyl group as the organic binder (B) in place of the 4% by weight aqueous solution: 25 parts by mass (solid content: 1 part by mass) of the polyvinyl alcohol “GOHSENOL NL-05” used in Example 1 Except using polyvinyl alcohol (Nippon Synthetic Chemical Co., Ltd. "GOHSEFIMAR Z-100" 4 mass% aqueous solution: 125 mass parts (solid content: 5 mass parts) and ion-exchanged water at 25 mass parts. In the same manner as in Example 1, an easily deformable aggregate having an average particle diameter of about 15 μm, an average compression force required for a compression deformation ratio of 10%: about 1.8 mN, and an average particle diameter maintenance ratio after a shaking test of 90% ( D-9) was obtained.

(Example 10)
Boron nitride particles “NX-5” as thermal conductive particles (A): 100 parts by mass, 4% by mass toluene solution of polyester resin (Toyobo Co., Ltd .: Byron 200) as organic binder (B): 125 masses Average particle size in the same manner as in Example 1, except that 25 parts by mass of toluene (solid content: 5 parts by mass) was used instead of 25 parts by mass of toluene instead of ion-exchanged water, and the spray drying temperature was changed from 125 ° C to 140 ° C. An easily deformable aggregate (D-10) having a diameter of about 25 μm, an average compressive force required for a compressive deformation ratio of 10%: about 4 mN, and an average particle diameter maintenance ratio after a shaking test of 88% was obtained.

(Example 11)
Instead of the polyester resin used in Example 10, a 10% by weight toluene solution of a polyurethane resin (Toyobo Co., Ltd .: Byron UR-1400) as an organic binder (B): 20 parts by mass (solid content: 2 parts by mass) In the same manner as in Example 10, except that toluene was changed to 100 parts by mass, the average particle size required was about 3.8 mN for the average particle size of about 20 μm and the compression deformation rate was 10%, and the average after the shaking test. Maintenance rate of particle size: 88% easily deformable aggregate (D-11) was obtained.

Example 12
Boron nitride particles “NX-5” as heat conductive particles (A): 100 parts by mass, 20% by mass aqueous solution of polyvinyl alcohol “Gosenol NL-05” as organic binder (B): 10 parts by mass (solid (Dispersion: 2 parts by mass), dispersion of silver nanowires obtained in Fiber Synthesis Example 1 (P1): 333.3 parts by mass (solid content: 1 part by mass), and ion-exchanged water: 6.7 parts by mass And stirred at 1000 rpm for 1 hour to obtain a slurry.
This slurry is spray-dried in a mini-spray dryer (“B-290” manufactured by Nihon Büch) in an atmosphere of 125 ° C., and the average compression force required for an average particle size of about 30 μm and a compression deformation rate of 10% is about 1. An easily deformable aggregate (D-12) having a maintenance rate of 2 mN and an average particle diameter after the shaking test of 92% was obtained.

(Example 13)
Boron nitride particles “PT140” as heat conductive particles (A): 100 parts by mass, and 20% by mass aqueous solution of polyvinyl alcohol “GOHSENOL NL-05” as organic binder (B): 25 parts by mass (solid content: 5 parts by mass), a dispersion of copper silver nanowires obtained in Fiber Synthesis Example 2 (P2) solution: 222.2 parts by mass (solid content: 0.4 parts by mass), and ion-exchanged water: 2.8 parts by mass Except for use, in the same manner as in Example 12, the average particle size of about 50 μm, the average compression force required for the compression deformation rate of 10%: about 0.6 mN, the maintenance rate of the average particle size after the shaking test: 89% Deformable aggregate (D-13) was obtained.

(Example 14)
Boron nitride particles “NX-1”: 100 parts by mass as thermal conductive particles (A), 20% by mass aqueous solution of polyvinyl alcohol “Gosenol NL-05” as organic binder (B): 75 parts by mass (solid Min: 15 parts by mass), metal-coated polymer nanofibers (P3) obtained in Fiber Synthesis Example 2: 40 parts by mass, and ion-exchanged water: 35 parts by mass. An easily deformable aggregate (D-14) having a diameter of about 15 μm, an average compressive force required for a compressive deformation ratio of 10%: about 4 mN, and an average particle diameter maintenance ratio after shaking test of 93% was obtained.

(Example 15)
Boron nitride particles “NX-1” as heat conductive particles (A): 100 parts by mass, 4% by mass aqueous solution of polyvinyl alcohol “Gosenol NL-05” as organic binder (B): 125 parts by mass (solid Min: 5 parts by mass), carbon nanotube dispersion (“LB200” manufactured by Cano Technology, average fiber diameter of 11 nm, average fiber length of 10 μm) as carbon material (J): 100 parts by mass (solid content: 5 parts by mass), and ions Exchange water: Same as Example 12 except that 25 parts by mass was used, average particle size of about 15 μm, average compression force required for compression deformation rate of 10%: about 2.4 mN, average particle size after shaking test Maintenance rate: 88% easily deformable aggregates (D-15) were obtained.

(Example 16)
Boron nitride particles “NX-5” as heat conductive particles (A): 100 parts by mass, polyvinyl alcohol “Gosenol NL-05” as organic binder (B): 50 parts by mass (solid content: 2 parts by mass) ), XG Sciences (scale-like graphene powder M grade, average aspect ratio 3000, average thickness 3 nm): 1 part by mass, and ion-exchanged water: 100 parts by mass, except that 100 parts by mass were used as the carbon material (J). Similarly, an easily deformable aggregate (D16) having an average particle diameter of about 30 μm, an average compression force required for a compression deformation ratio of 10%: about 3 mN, and an average particle diameter maintenance ratio after a shaking test of 86% was obtained. .

(Comparative Example 1)
Instead of boron nitride particles “NX-1” as thermal conductive particles (A), boron nitride particles “SGP” (manufactured by Denki Kagaku Kogyo Co., Ltd., average primary particle size: about 18 μm, circularity: 0.5, compression The average compressive force required for a deformation rate of 10% is about 150 mN), except that the above-mentioned polyvinyl alcohol 4 mass% aqueous solution: 125 parts by weight (solid content: 5 parts by weight) and ion-exchanged water: 25 parts by mass are used. In the same manner as in Example 3, an attempt was made to obtain an easily deformable aggregate, but a product (D′-1) that was easily disintegrated and did not form an aggregate was obtained.

(Comparative Example 2)
An attempt was made to obtain an easily deformable aggregate in the same manner as in Example 4 except that polyvinyl alcohol was not used and ion exchange water was changed to 150 parts by mass. A product (D′-2) was obtained.

(Comparative Example 3)
The average compressive force required for an average particle size of about 80 μm and a compressive deformation rate of 10% is about 10 mN in the same manner as in Example 4 except that the 20% by weight aqueous solution of polyvinyl alcohol is 250 parts by weight (solid content: 50 parts by weight). The retention rate of the average particle diameter after the shaking test: 90% easily deformable aggregates (D′-3) were obtained.

(Comparative Example 4)
Without using a 4% by mass aqueous solution of polyvinyl alcohol, using a silane coupling agent (“KBM-04” (10% by mass solution) manufactured by Shin-Etsu Chemical Co., Ltd.): 20 parts by mass (solid content: 2 parts by mass), ion-exchanged water A slurry was obtained in the same manner as in Example 5 except that the content was 130 parts by mass. The slurry was spray-dried and cured in an atmosphere of 125 ° C., and an average compression force required for an average particle diameter of about 40 μm and a compression deformation rate of 10%: About 42 mN, an easily deformable aggregate (D′-4) having an average particle diameter maintenance rate after shaking test of 75% was obtained.

(Comparative Example 5)
A slurry similar to that of Comparative Example 4 was obtained, and the slurry was spray-dried in an atmosphere of 125 ° C. and then sintered at 3000 ° C. above the melting point of boron nitride, and the average required for an average particle diameter of about 40 μm and a compression deformation rate of 10%. An easily deformable aggregate (D′-5) having a compressive force of about 150 mN and an average particle diameter retention rate after shaking test of 97% was obtained.

(Comparative Example 6)
A slurry similar to that of Example 1 was obtained, and this slurry was spray-dried in an atmosphere of 125 ° C. and then heated at 800 ° C. above the decomposition temperature of the organic binder to obtain an easily deformable aggregate. It was easy to do and the product (D'-6) which does not comprise the state of an aggregate was obtained.

Table 1 shows main production conditions and evaluation results in Examples 1 to 16 and Comparative Examples 1 to 6.
As shown in Table 1, in order to produce an aggregate, the average primary particle diameter of the heat conductive particles (A) is 15 μm or less, and it is necessary to use an organic binder (B). As shown in Comparative Examples 4 and 5, the thermally conductive particles (A) are firmly bound to each other, such as using a silane coupling agent as an organic binder or sintering at a melting point of alumina or higher. And, it becomes poorly deformable.

(Example 101)
45.0 parts by mass of the easily deformable aggregate (D-1) (average particle size 15 μm) obtained in Example 1 and the polyurethane polyurea resin (E) obtained in Resin Synthesis Example 1 as the binder resin (E) -1) 20.0 parts by mass of 25% MEK solution and 2.0 parts by mass of 50% MEK solution of bisphenol A type epoxy resin ("Epicoat 1001" manufactured by Japan Epoxy Resin Co., Ltd.) are mixed by disper stirring. After adjusting the solvent (F) to 7.1 parts by weight of isopropyl alcohol and 28.4 parts by weight of toluene so that the solid content is 50% by weight, the mixture is ultrasonically degassed, and the content of easily deformable aggregates is 70 vol. % Heat conductive resin composition (G-1) was obtained.
The obtained thermally conductive resin composition was applied to a release-treated sheet (a release-treated polyethylene terephthalate film having a thickness of 75 μm) using a comma coater, dried by heating at 100 ° C. for 2 minutes, and the thickness of the thermally conductive layer Obtained the heat conductive member (H-1) of 50 micrometers. The thermal conductivity was 8 (W / m · K).

(Example 102)
The release treatment sheet was stacked on the heat conductive layer of the heat conductive member (H-1) obtained in Example 101, and pressed at 150 ° C. for 2 hours at 2 MPa. The thickness of the heat conductive layer was 48 μm, and easily deformable. A heat conductive member (I-2) having an aggregate content of 70 vol% and a heat conductivity of 10 (W / m · K) was obtained.

(Example 103)
The polyurethane polyurea resin (E) obtained in Resin Synthesis Example 1 as 37.0 parts by mass of the easily deformable aggregate (D-2) (average particle size 5 μm) obtained in Example 2 and the binder resin (E) -1) 52.0 parts by mass of 25% MEK solution and 5.2 parts by mass of 50% MEK solution of bisphenol A type epoxy resin (“Epicoat 1001” manufactured by Japan Epoxy Resin Co., Ltd.) The solvent (F) was adjusted to 2.3 parts by weight of isopropyl alcohol and 9.2 parts by weight of toluene so that the solid content was 50% by weight, and then ultrasonically degassed so that the content of easily deformable aggregates was 50 vol. % Heat conductive resin composition (G-3) was obtained.
The obtained heat conductive resin composition (G-3) was coated on a release treatment sheet (a release treatment polyethylene terephthalate film having a thickness of 75 μm) using a comma coater, and dried by heating at 100 ° C. for 2 minutes. A heat conductive member (H-3) having a heat conductive layer thickness of 60 μm and a heat conductivity of 6.5 (W / m · K) was obtained. Further, the release treatment sheet is stacked on the heat conductive layer and pressed at 150 ° C. and 2 MPa for 1 hour, and the heat conductive layer (I / W · m · K) having a thickness of 55 μm and a heat conductivity of 8 (W / m · K) -3) was obtained.

(Example 104) to (Example 121)
Based on the composition of Table 2, the thermal conductive compositions (G-4) to (G-21), the thermal conductive members (H-4) to (H-21), and the thermal conductive member in the same manner as in Example 103. (I-4 to I-21) were obtained.

(Comparative Example 101)
45.0 parts by mass of boron nitride powder (“NX-1” manufactured by Momentive Performance Materials Japan, average primary particle size: 0.7 μm, circularity 0.6) and binder resin (E), 20.0 parts by mass of 25% MEK solution of polyurethane polyurea resin (E-1) obtained in Resin Synthesis Example 1 and 50% MEK solution of bisphenol A type epoxy resin (“Epicoat 1001” manufactured by Japan Epoxy Resin Co., Ltd.) 2.0 parts by mass with disper stirring, and after adjusting the solvent (F) to 7.1 parts by mass of isopropyl alcohol and 28.4 parts by mass of toluene so that the solid content is 50% by weight, ultrasonic desorption is performed. Foaming was performed to obtain a thermally conductive resin composition (G′-1) having a boron nitride content of 70 vol%.
The obtained thermally conductive resin composition (G′-1) was applied to a release-treated sheet (a release-treated polyethylene terephthalate film with a thickness of 75 μm) using a comma coater, and dried by heating at 100 ° C. for 2 minutes. A heat conductive member (H′-1) having a heat conductive layer thickness of 50 μm and a heat conductivity of 0.7 (W / m · K) was obtained. Further, the release treatment sheet was stacked on the heat conductive layer and pressed at 150 ° C. and 2 MPa for 1 hour to obtain a heat conductive member (I′-1) having a heat conductive layer thickness of 45 μm. The thermal conductivity of this sheet was as low as 0.7 (W / m · K).

(Comparative Example 102)
The polyurethane polyurea resin (E-1) obtained in Resin Synthesis Example 1 was used as 37.0 parts by mass of (D′-1) (cannot form an aggregate) obtained in Comparative Example 1 and the binder resin (E). ) And 52.0 parts by mass of a 50% MEK solution of bisphenol A type epoxy resin (“Epicoat 1001” manufactured by Japan Epoxy Resin Co., Ltd.) by stirring with a disper. F) After adjusting 2.3 parts by weight of isopropyl alcohol and 9.2 parts by weight of toluene so that the solid content becomes 50% by weight, ultrasonic degassing was performed, and the content of (D′-1) was 50 vol. % Heat conductive resin composition (G′-2) was obtained.
The obtained thermally conductive resin composition (G′-2) was applied to a release-treated sheet (a release-treated polyethylene terephthalate film with a thickness of 75 μm) using a comma coater, and dried by heating at 100 ° C. for 2 minutes. A heat conductive member (H′-2) having a heat conductive layer thickness of 50 μm and a heat conductivity of 0.9 (W / m · K) was obtained. Further, the release treatment sheet was stacked on the heat conductive layer and pressed at 150 ° C. and 2 MPa for 1 hour to obtain a heat conductive member (I′-2) having a heat conductive layer thickness of 43 μm. The thermal conductivity of this sheet was as low as 1 (W / m · K).

(Comparative Example 103) to (Comparative Example 110)
Based on the composition of Table 2, in the same manner as in Comparative Example 102, the heat conductive compositions (G′-3) to (G′-10), the heat conductive members (H′-3) to (H′-10), Thermally conductive members (I′-3 to I′-10) were obtained. Any thermal conductive member (I ′) had a thermal conductivity of 0.3 to 0.9 (W / m · K). It was low.
At this time, in Comparative Example 109, the filling amount of the heat conductive particles (D-1) was excessive, and a continuous film could not be formed. In Comparative Example 110, the organic binder (B) was dissolved in the solvent while the binder (E), the solvent (F), and the easily deformable aggregate (D-11) were being mixed. The collapse of was observed.
In addition, only the solvent (F) in Table 2 was added as a solvent.

In Table 2, each symbol represents the following components.
Byron UR6100: Polyester urethane resin (Toyobo Co., Ltd.)
Polysol AX-590: Water-based emulsion resin (made by Showa Denko KK)
Polysol AD-11: Water-based emulsion resin (made by Showa Denko KK)
AO-509: Spherical alumina (manufactured by Admatechs, average primary particle size is 10 μm)

As shown in Table 2, the thermally conductive resin composition (G) of the present invention provides a thermally conductive member (I) excellent in thermal conductivity and heat resistance.
Although heat conductive particles are contained in the heat conductive resin composition (G) as in Comparative Examples 101 to 103 and 107, the heat conductive particles are not aggregates, or heat transfer as in Comparative Examples 104 to 106. When the conductive resin composition (G) contains aggregates of thermally conductive particles, but the aggregates are not easily deformable, sufficient thermal conductivity cannot be expressed. Further, as shown in Comparative Example 104, when the amount of the organic binder (B) is excessive, sufficient thermal conductivity cannot be exhibited in that the organic binder (B) inhibits thermal conductivity.
As shown in Comparative Example 108, if the amount of the easily deformable aggregate (D) in the composition is insufficient, sufficient thermal conductivity may not be exhibited. As shown in Comparative Example 109, if the amount of the easily deformable aggregate (D) in the composition is excessive, film formation may not be possible. As shown in Comparative Example 110, a sufficient thermal conductivity cannot be exhibited even if the aggregate collapses during the production of the resin composition.

The easily deformable aggregate of the present invention and the heat conductive resin composition containing the same can be preferably used for a heat conductive member such as a heat conductive adhesive sheet.

Claims (12)

100 parts by mass of non-spherical thermally conductive particles (A) having an average primary particle size of 0.1 to 15 μm and an average circularity of less than 0.9 ;
Including 0.1 to 30 parts by mass of an organic binder (B) selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, modified polyvinyl alcohol, polyester resin, and polyurethane resin ,
An easily deformable aggregate (D) having an average particle diameter of 2 to 100 μm and an average compression force required for a compression deformation rate of 10% of 5 mN or less.
However, the non-spherical thermally conductive particles (A) have a diameter of 0.3 to 50000 nm, a thermally conductive fiber (P) having a length of 1 to 5000 μm, an average fiber diameter of 5 to 30 nm, and an average fiber length. The average circularity is 0.9 excluding the carbon material (J) of 0.1 to 20 μm and the plate-like or scale-like carbon material having an average aspect ratio of 10 to 3000 and an average thickness of 0.1 to 500 nm. Smaller than boron nitride. The organic binder (B) has a nitrogen atom, according to claim 1 Symbol placement of easily deformable aggregates (D). The easily deformable aggregate (D) according to claim 1 or 2 , wherein the organic binder (B) has a reactive functional group. The easily deformable aggregate (D) according to any one of claims 1 to 3, wherein the noncircular thermally conductive particles (A) have an average circularity of 0.25 to 0.6 . The easily deformable aggregate (D) according to any one of claims 1 to 4 is 20 to 90% by volume based on the solid content, the binder resin (E) is 10 to 80% by volume based on the solid content, and the binder resin. The heat conductive resin composition (G) containing the solvent (F) which melt | dissolves (E). The thermally conductive resin composition according to claim 5, wherein the organic binder (B) constituting the easily deformable aggregate (D) is a water-soluble resin, and the binder resin (E) is a water-insoluble resin. (G). The heat conductive member (H) containing the heat conductive layer by which a solvent (F) is removed from the heat conductive resin composition (G) of Claim 5 or 6 . The heat conductive member (H) of Claim 7 whose ratio of the average particle diameter of the easily deformable aggregate (D) with respect to the thickness of the said heat conductive layer is 20% or more. The heat conductive member (I) formed by pressurizing the heat conductive member (H) according to claim 7 or 8 . The heat conductive member (H) according to claim 7 or 8 , or the heat conductive member (I) according to claim 9 ,
A thermally conductive adhesive sheet having a release film on at least one surface. It is a manufacturing method of the easily deformable aggregate (D) of any one of Claims 1-4,
100 parts by mass of thermally conductive particles (A) having an average primary particle size of 0.1 to 15 μm and an average circularity of less than 0.9 ;
0.1 to 30 parts by mass of an organic binder (B) selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, modified polyvinyl alcohol, polyester resin, and polyurethane resin ;
Obtaining a slurry containing a solvent (C) capable of dissolving the organic binder and (B),
Removing the solvent (C) from the slurry.
Manufacturing method of easily deformable aggregate (D).
However, the non-spherical thermally conductive particles (A) have a diameter of 0.3 to 50000 nm, a thermally conductive fiber (P) having a length of 1 to 5000 μm, an average fiber diameter of 5 to 30 nm, and an average fiber length. The average circularity is 0.9 excluding the carbon material (J) of 0.1 to 20 μm and the plate-like or scale-like carbon material having an average aspect ratio of 10 to 3000 and an average thickness of 0.1 to 500 nm. Smaller than boron nitride. Applying the thermally conductive resin composition (G) according to any one of claims 1 to 6 on a substrate to form a coating film;
Removing the solvent (F) from the coating film to form a heat conductive layer;
Pressing the heat conductive layer.
Manufacturing method of heat conductive member (I).