JP2023114333A - Composition - Google Patents

Abstract

To provide a composition which contains a tetrafluoroethylene-based polymer and predetermined inorganic particles, is excellent in dispersibility and moldability, and can form a molded product low in linear expansion coefficient, dielectric constant and dielectric loss tangent and excellent in adhesion to a substrate, thermal conductivity and heat dissipation.SOLUTION: The composition contains a tetrafluoroethylene-based polymer and hydrophobic inorganic particles surface-treated with a coupling agent. The coupling agent is a compound in which a trialkoxysilyl group and a functional group are bonded via a linking group containing one or more selected from an imino bond, an amide bond, a urea bond, a urethane bond and a carbodiimide bond.SELECTED DRAWING: None

Description

The present invention relates to a composition comprising a tetrafluoroethylene-based polymer and inorganic particles.

In recent years, in order to respond to the high speed and high frequency of mobile communication devices such as mobile phones, materials with high thermal conductivity, low coefficient of linear expansion, low dielectric constant and low dielectric loss tangent are required for printed circuit boards of communication devices. A tetrafluoroethylene-based polymer, which has a low dielectric constant and a low dielectric loss tangent, has attracted attention.
In addition, in order to prevent problems caused by heat from high-heat-generating components, which accompanies the increasing speed and integration of circuits in electrical and electronic equipment, and the increasing density of electronic density mounting on circuit boards, printed circuit board materials must have heat dissipation properties. It has been demanded. In addition, there is a demand for a material that efficiently dissipates heat generated from electronic components and that has superior thermal conductivity and heat dissipation.
Compositions of tetrafluoroethylene-based polymers and inorganic particles have been investigated in order to obtain materials with low dielectric properties and excellent thermal conductivity. Patent Literature 1 discloses a resin composition for a circuit board containing a melt-processable fluororesin and boron nitride particles having a specific particle diameter and a particle abundance ratio within a predetermined range. Patent Literature 2 discloses a composition containing hexagonal boron nitride particles whose surfaces having a concave structure are treated with a metal coupling agent, and a resin.

WO2021/010320 JP 2019-137581 A

A tetrafluoroethylene-based polymer has a low surface tension and low affinity with other components. It may not be fully expressed.
The present inventors have found that the compositions of Patent Documents 1 and 2 described above have a low coefficient of linear expansion and excellent electrical properties, and form moldings that are particularly excellent in adhesion to the substrate, thermal conductivity, and heat dissipation. The inventors have found that it is difficult to obtain a composition capable of
The present inventors have found that a composition containing a tetrafluoroethylene-based polymer and predetermined inorganic particles surface-treated with a specific coupling agent is excellent in dispersibility and moldability, and the molded product has a coefficient of linear expansion, The inventors have found that the dielectric constant and dielectric loss tangent are low, and that they are excellent in adhesion to substrates, thermal conductivity, and heat dissipation, leading to the present invention.
It is an object of the present invention to provide such compositions.

The present invention has the following aspects.
[1] Containing a tetrafluoroethylene-based polymer and hydrophobic inorganic particles surface-treated with a coupling agent, the coupling agent comprising a trialkoxysilyl group and a functional group having an imino bond, an amide bond, or a urea A composition, which is a compound bonded via a linking group containing at least one selected from a bond, a urethane bond, and a carbodiimide bond.
[2] The composition of [1], wherein the tetrafluoroethylene-based polymer is a hot-melt tetrafluoroethylene-based polymer having a melting temperature of 180° C. or higher.
[3] The composition of [1] or [2], wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having an oxygen-containing polar group.
[4] The composition according to any one of [1] to [3], wherein the tetrafluoroethylene-based polymer is particulate.
[5] The composition according to any one of [1] to [4], wherein the inorganic particles have a surface hydroxyl group content of 50/nm ² or less.
[6] The composition according to any one of [1] to [5], wherein the inorganic particles are at least one selected from the group consisting of alumina, cristobalite, boron nitride, magnesium oxide, mica, forsterite and cordierite. .
[7] The composition according to any one of [1] to [6], wherein the inorganic particles have an average particle size of less than 15 μm.
[8] The composition according to any one of [1] to [7], wherein the coupling agent is at least one selected from benzotriazole-functional silane coupling agents and epoxy-functional silane coupling agents. .
[9] The composition according to any one of [1] to [8], wherein the content ratio (mass ratio) of the inorganic particles to the tetrafluoroethylene-based polymer is greater than 1.
[10] The composition of any one of [1] to [9], which is liquid or powdery.
[11] A cup, which is a compound in which a trialkoxysilyl group and a functional group are bonded via a linking group containing one or more selected from imino bonds, amide bonds, urea bonds, urethane bonds, and carbodiimide bonds. Hydrophobic inorganic particles surface-treated with a coupling agent, used in the composition according to any one of [1] to [10], wherein the hydrophobic inorganic particles are sheared in a solution containing a ring agent. manufacturing method.
[12] The method for producing inorganic particles according to [11], wherein the shearing treatment is performed by mixing in a tank equipped with a stirring mechanism using thin film rotation or a stirring mechanism using rotation and revolution.
[13] A composition containing a tetrafluoroethylene-based polymer and hydrophobic inorganic particles obtained by the production method of [11] or [12], and containing the tetrafluoroethylene-based polymer and the inorganic particles. A method for producing a composition according to any one of [1] to [10], which obtains
[14] Applying the composition of any one of [1] to [10] to the surface of a substrate and heating to form a polymer layer containing the tetrafluoroethylene-based polymer and the inorganic particles, and A laminate manufacturing method for obtaining a laminate having a substrate layer composed of a material and the polymer layer.
[15] A laminate having a substrate layer and a polymer layer containing the tetrafluoroethylene-based polymer and the inorganic particles, formed from the composition according to any one of [1] to [10].

ADVANTAGE OF THE INVENTION According to this invention, the composition which contains a tetrafluoroethylene-type polymer and a predetermined inorganic particle, and is excellent in dispersion stability and moldability is provided. From such a composition, a molded product having a low coefficient of linear expansion, a low dielectric constant and a low dielectric loss tangent, and excellent adhesion to a substrate, thermal conductivity and heat dissipation can be formed.

The following terms have the following meanings.
"Average particle diameter (D50)" is the volume-based cumulative 50% diameter of particles determined by a laser diffraction/scattering method. That is, the particle size distribution is measured by a laser diffraction/scattering method, and the cumulative curve is obtained with the total volume of the group of particles being 100%.
The D50 of the particles is obtained by dispersing the particles in water and analyzing them by a laser diffraction/scattering method using a laser diffraction/scattering particle size distribution analyzer (LA-920 measuring instrument manufactured by Horiba, Ltd.).
"Melting temperature" is the temperature corresponding to the maximum melting peak of the polymer as measured by differential scanning calorimetry (DSC).
"Glass transition point (Tg)" is a value determined by analyzing a polymer by dynamic viscoelasticity measurement (DMA).
"Viscosity" is determined by measuring a composition using a Brookfield viscometer at 25°C and a rotation speed of 30 rpm. The measurement is repeated 3 times, and the average value of the 3 measurements is taken.
The “thixotropic ratio” is a value calculated by dividing the viscosity η ₁ of the composition measured at a rotation speed of 30 rpm by the viscosity η ₂ measured at a rotation speed of 60 rpm. Each viscosity measurement is repeated three times, and the average value of the three measurements is taken.
A "unit" in a polymer means an atomic group based on the monomer formed by polymerization of the monomer. The units may be units directly formed by a polymerization reaction, or may be units in which some of said units have been converted to another structure by treatment of the polymer. Hereinafter, units based on monomer a are also simply referred to as "monomer a units".

The composition of the present invention (hereinafter also referred to as "this composition") comprises a tetrafluoroethylene-based polymer (hereinafter also referred to as "F polymer") and a hydrophobic inorganic polymer surface-treated with a coupling agent. particles (hereinafter also referred to as "present inorganic particles"), and the coupling agent has a trialkoxysilyl group and a functional group selected from an imino bond, an amide bond, a urea bond, a urethane bond and a carbodiimide bond. It is a compound bound via a linking group containing any one or more.

This composition has excellent dispersibility, and from this composition, it has high physical properties of F polymer and inorganic particles, low linear expansion coefficient, low dielectric constant and dielectric loss tangent, adhesion to substrates, heat conduction It is easy to form a molded product with excellent heat resistance and heat dissipation. Although the reason is not necessarily clear, it is considered as follows.

Since the F polymer has a low surface energy, the F polymers tend to agglomerate with each other. Furthermore, since the affinity between the F polymer and the inorganic particles is low, it is difficult to obtain a composition in which the F particles and the inorganic particles are well dispersed. This tendency tends to become more pronounced as the ratio of hydrophobic inorganic particles and inorganic particles contained in the composition increases. Adhesion to the material is also likely to decrease.
The present inorganic particles contained in the present composition are preferably produced by shearing hydrophobic inorganic particles in a solution containing a specific coupling agent. By such a method, surface roughening of the inorganic particles proceeds without impairing the properties and physical properties of the inorganic particles as a whole, and the trialkoxysilyl groups of the specific coupling agent are highly bonded to the surfaces of the roughened inorganic particles. The inorganic particles are formed. At this time, the functional groups possessed by the specific coupling agent are believed to be highly exposed on the surface of the present inorganic particles because they are bonded through specific rigid linking groups. This not only enhances the affinity between the F polymer and the inorganic particles and improves the dispersibility of the composition, but also allows the F polymer and the inorganic particles to interact with each other due to the action of the functional groups of the coupling agent during molding formation. It is believed that the formation of a network structure between particles is promoted, thereby improving the interfacial adhesion between the two components and the adhesion between the molding and the substrate.
As a result, the physical properties of the F polymer and the inorganic particles are highly equipped, specifically, the linear expansion coefficient, dielectric constant and dielectric loss tangent are low, and the adhesiveness to the substrate, thermal conductivity and heat dissipation are excellent. Moldings are believed to have been obtained from this composition.

The F polymer in the present invention is a polymer containing units (hereinafter also referred to as "TFE units") based on tetrafluoroethylene (hereinafter also referred to as "TFE").
The F polymer may be hot-meltable or non-hot-meltable. Here, the hot-melt polymer means a polymer having a temperature at which the melt flow rate is 1 to 1000 g/10 minutes under a load of 49 N. A non-thermally fusible polymer means a polymer that does not have a temperature at which the melt flow rate is 1 to 1000 g/10 minutes under a load of 49N.
The melting temperature of the heat-meltable F polymer is preferably 180° C. or higher, more preferably 200° C. or higher, and even more preferably 260° C. or higher. The melting temperature of the F polymer is preferably 325° C. or lower, more preferably 320° C. or lower. The melting temperature of the F polymer is preferably 180°C to 320°C. In this case, the present composition tends to be excellent in processability, and a molded article formed from the present composition tends to be excellent in heat resistance.

The glass transition point of F polymer is preferably 50° C. or higher, more preferably 75° C. or higher. The glass transition point of the F polymer is preferably 150° C. or lower, more preferably 125° C. or lower.
The fluorine content of the F polymer is preferably 70% by mass or more, more preferably 72 to 76% by mass. Such F polymer having a high fluorine content has particularly low affinity with inorganic particles, but according to the present invention, a composition excellent in dispersibility (this composition) can be obtained due to the mechanism of action described above.
The surface tension of the F polymer is preferably 16-26 mN/m. The surface tension of the F polymer can be measured by placing a droplet of a liquid mixture for wet tension test (manufactured by Wako Pure Chemical Industries, Ltd.) specified in JIS K 6768 on a flat plate made of the F polymer. .

F polymers are polytetrafluoroethylene (PTFE), polymers containing TFE units and ethylene-based units (ETFE), polymers containing TFE units and propylene-based units, TFE units and ethylene-based units and propylene-based (EFEP), polymer (PFA) containing TFE units and units based on perfluoro(alkyl vinyl ether) (PAVE) (PAVE units), polymers containing TFE units and units based on hexafluoropropylene (FEP ) are preferred, PFA and FEP are more preferred, and PFA is even more preferred. These polymers may also contain units based on other comonomers.
PAVE is preferably CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ and CF ₂ =CFOCF ₂ CF ₂ CF ₃ (hereinafter also referred to as “PPVE”), more preferably PPVE.

The F polymer preferably has an oxygen-containing polar group, more preferably a hydroxyl group-containing group or a carbonyl group-containing group, even more preferably a carbonyl group-containing group.
In this case, the F polymer easily interacts with the present inorganic particles, and the present composition tends to have excellent dispersibility. In addition, from the present composition, it is easy to obtain a molded article having a low coefficient of linear expansion, a low dielectric constant and a low dielectric loss tangent, and having excellent thermal conductivity and adhesiveness.
The hydroxyl group-containing group is preferably a group containing an alcoholic hydroxyl group, more preferably -CF ₂ CH ₂ OH and -C(CF ₃ ) ₂ OH.
A carbonyl group-containing group includes a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC(O)NH ₂ ), an acid anhydride residue (-C(O)OC(O)-), an imide Residue (-C(O)NHC(O)-, etc.), formyl group, halogenoformyl group, urethane group (-NHC(O)O-), carbamoyl group (-C(O)-NH ₂ ), ureido group (—NH—C(O)—NH ₂ ), oxamoyl group (—NH—C(O)—C(O)—NH ₂ ) and carbonate group (—OC(O)O—) are preferred, and acid anhydride Residues are more preferred.
When the F polymer has oxygen-containing polar groups, the number of oxygen-containing polar groups in the F polymer is preferably 10 to 5,000, more preferably 100 to 3,000 per 1×10 ⁶ carbon atoms in the main chain. The number of oxygen-containing polar groups in the F polymer can be quantified by the composition of the polymer or the method described in WO2020/145133.

The oxygen-containing polar group may be contained in a unit based on a monomer in the F polymer, or may be contained in a terminal group of the main chain of the F polymer, the former being preferred. Examples of the latter embodiment include an F polymer having an oxygen-containing polar group as a terminal group derived from a polymerization initiator, a chain transfer agent, etc., and an F polymer obtained by subjecting the F polymer to plasma treatment or ionizing radiation treatment.
The monomer having a carbonyl group-containing group is preferably itaconic anhydride, citraconic anhydride and 5-norbornene-2,3-dicarboxylic anhydride (hereinafter also referred to as "NAH"), more preferably NAH.

The F polymer is preferably a polymer having carbonyl-containing groups containing TFE units and PAVE units, comprising units based on monomers containing TFE units, PAVE units and carbonyl-containing groups, for all units: More preferably, the polymer contains 90 to 99 mol %, 0.99 to 9.97 mol %, and 0.01 to 3 mol % of these units in this order. Specific examples of such F polymers include the polymers described in WO2018/16644.

In the present invention, the F polymer is preferably particulate (hereinafter referred to as "F particles"). D50 of F particles is preferably 0.01 μm or more, more preferably 0.3 μm or more, and even more preferably 1 μm or more. D50 of the F particles is preferably less than 10 μm, more preferably less than 8 μm. In this case, the present composition tends to be excellent in dispersibility and workability. In addition, from the present composition, it is easy to obtain a molded article having a low coefficient of linear expansion, a low dielectric constant and a low dielectric loss tangent, excellent adhesion to a substrate, excellent thermal conductivity and heat dissipation.
The specific surface area of the F particles is preferably 1 to 25 m ² /g.

One type of F particles may be used, or two or more types may be used. The F particles are preferably at least particles of a heat-melting F polymer, more preferably particles of a heat-melting F polymer having an oxygen-containing polar group and having a melting temperature of 180°C to 320°C. In this case, the dispersibility of the present composition is likely to be improved.

When two types of F particles are used, the F particles are preferably a mixture of hot melt F polymer particles and non-hot melt F polymer particles. In this case, the effect of suppressing aggregation by the particles of the hot-melt F polymer and the retention effect of the fibrillation of the non-heat-meltable F polymer are balanced, and the dispersibility of the present composition is likely to be improved. In addition, the molded article obtained therefrom exhibits the electrical properties of the non-thermally fusible F polymer to a high degree, and a molded article having a particularly low dielectric loss tangent is easily obtained.
The former particles are preferably particles of a heat-melting F polymer having a melting temperature of 200 to 320° C., more preferably particles of a heat-melting F polymer having a melting temperature of 180 to 320° C. and having an oxygen-containing polar group. preferable. Preferred embodiments of the heat-meltable F polymer having oxygen-containing polar groups in the former particles are the same as the preferred embodiments of the above-mentioned F polymer having oxygen-containing polar groups.
As the latter particles, particles of non-thermally fusible PTFE are preferred.
The ratio of the former particles to the total mass of the two types of F particles is preferably 50% by mass or less, more preferably 40% by mass or less. Moreover, the ratio is preferably 5% by mass or more, more preferably 10% by mass or more.
The former particles preferably have a D50 of 1 to 4 μm, and the latter particles preferably have a D50 of 0.1 to 1 μm.

The F particles may contain a resin or an inorganic compound other than the F polymer, and may form a core-shell structure in which the F polymer is the core and the resin or inorganic compound other than the F polymer is the shell. may form a core-shell structure in which a resin or an inorganic compound other than the F polymer is used as a core.
Here, examples of resins other than F polymer include aromatic polyesters, polyamideimides, polyimides and maleimides, and examples of inorganic compounds include silica and boron nitride.

The hydrophobic inorganic particles used in the present invention preferably have a surface hydroxyl group content of 100/nm ² or less, more preferably 50/nm ² or less.
The amount of surface hydroxyl groups per unit amount of inorganic particles is measured by the following method.
1.5 g of inorganic particles are weighed, adjusted with 0.1 mol/L hydrochloric acid so that the pH is about 3, and diluted with distilled water to make the total amount 150 g. 0.1 mol/L sodium hydroxide is added dropwise to this prepared solution, and the amount required to reach a pH of 9 is determined. Substituting this into the following formula (1), the amount of surface hydroxyl groups is calculated.
Amount of surface hydroxyl groups (number/nm ² )=[Amount of sodium hydroxide of 0.1 mol/L×6×10 ²³ ]/[Amount of inorganic particles×specific surface area] Equation (1)

The shape of the hydrophobic inorganic particles may be spherical, needle-like (fibrous), or plate-like. It may be crown-shaped, equiaxed, leaf-shaped, mica-shaped, block-shaped, tabular, wedge-shaped, rosette-shaped, network-shaped, or prismatic, and preferably scale-shaped. In this case, the inorganic particles tend to form thermally conductive paths in a molded article formed from the present composition, and the molded article tends to be excellent in thermal conductivity and low linear expansion.

Inorganic compounds in the hydrophobic inorganic particles include carbon, inorganic nitrides or inorganic oxides. For example, carbon fiber, glass, boron nitride, silicon nitride, aluminum nitride, beryllia, silica, cristobalite, alumina (aluminum oxide), wollastonite, mica, talc, cerium oxide, magnesium oxide, zinc oxide, forsterite (2MgO・SiO ₂ ), cordierite (2MgO.2Al _{2 O} 3.5SiO ₂ ) or titanium oxide. Among them, alumina, cristobalite, boron nitride, magnesium oxide, mica, forsterite and cordierite are preferred from the viewpoint of the dispersion stability of the present composition and the thermal conductivity and heat dissipation properties of moldings formed from the present composition. It is preferably at least one selected from the group, more preferably boron nitride, and still more preferably hexagonal boron nitride.
Specific examples of boron nitride particles include "UHP" series (manufactured by Showa Denko KK) and "GP" and "HGP" grades of the "Denka Boron Nitride" series (manufactured by Denka).
One type of hydrophobic inorganic particles may be used, or two or more types may be used.

When the hydrophobic inorganic particles are scaly hexagonal boron nitride particles, it is believed that the present composition and molded articles formed from the present composition tend to have a house-of-cards structure and form thermal conduction paths. As a result, the present composition is excellent in dispersibility, and the molded product tends to be excellent in low linear expansion, thermal conductivity and heat dissipation, which is preferable.

The average particle diameter (D50) of the hydrophobic inorganic particles is preferably less than 15 µm, more preferably less than 10 µm, and more preferably 8 µm or less. D50 of the hydrophobic inorganic particles is preferably 0.1 μm or more, more preferably 1 μm or more. Such hydrophobic inorganic particles with a small D50 tend to agglomerate themselves and have a low affinity for the F polymer. This composition) is obtained.
The aspect ratio of the hydrophobic inorganic particles is preferably 1 or more, more preferably 10 or more. The aspect ratio is preferably 10000 or less.

In the present inorganic particles, the hydrophobic inorganic particles have a linking group in which the trialkoxysilyl group and the functional group contain at least one selected from an imino bond, an amide bond, a urea bond, a urethane bond and a carbodiimide bond. The surface is treated with a coupling agent (hereinafter also referred to as "the present coupling agent") that is a compound that bonds via.
The trialkoxysilyl group in the present coupling agent includes, for example, a trimethoxysilyl group and a triethoxysilyl group.
Examples of the functional group in the present coupling agent include triazine group, isocyanate group, isocyanuric acid group, benzotriazole group, acid anhydride group, azasilacyclopentane group, imidazole group, epoxy group, (meth)acrylic group, ( meth) acryloyloxy group, alkenyl group and styryl group. Among them, a benzotriazole group or an epoxy group is preferred. The coupling agent may have a plurality of functional groups of different types, or may have a plurality of functional groups of the same type.
The linking group includes, for example, a divalent organic group (alkylene group, alkylene group having an etheric oxygen atom between carbon atoms, etc.) as a main chain, imino bond, amide bond, urea bond, urethane bond and carbodiimide bond. Any group containing one or more selected from may be used.

The present coupling agent is a compound having the above-described functional group and a trimethoxysilyl group at both ends of the main chain containing the linking group; a compound having a plurality of triethoxysilyl groups in the chain; a compound having a siloxane structure in the main chain containing the linking group and functional groups at both ends of the main chain; a butadiene structure in the main chain containing the linking group a compound having one acid anhydride group and one trimethoxysilyl group in the side chain; a compound having an alkoxysiloxane structure in the main chain containing the linking group and a plurality of epoxy groups in the side chain; can be.

Specific examples of the present coupling agent include 3-isocyanatopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, tris(trimethoxysilylpropyl) isocyanurate, tris(triethylsilylpropyl) isocyanurate, 1-(3- (trimethoxysilyl)propyl)-3,5-di-2-propenyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(3 -(trimethoxysilyl)propyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, N-[5-(trimethoxysilyl)-2-aza-1-oxo Pentyl]caprolactam, N-[5-(triethoxysilyl)-2-aza-1-oxopentyl]caprolactam, N-[3-(triethoxysilyl)propyl]-ethylcarbamate, N-[3-(tri methoxysilyl)propyl]-ethylcarbamate, 3,5-dimethyl-N-[3-(trimethoxysilyl)propyl]-1H-pyrazole-1-carboxamide, 3,5-dimethyl-N-[3-( triethoxysilyl)propyl]-1H-pyrazole-1-carboxamide, 2-[3-(trimethoxysilyl)propyl]succinic anhydride, 2-[3-(triethoxysilyl)propyl]succinic anhydride, N-(trimethoxysilyl-propyl)-1H-benzotriazole-1-carbodiamide, dihydro-3-(trimethoxysilyl-propyl)-2,5-furandione, 2,2-dimethoxy-1-phenyl-1 -aza-2-silacyclopentane, N-2-pyridinyl-N-(triethoxysilyl-propyl)-urea, 3-[(trimethoxysilyl)propyl]-1H-imidazole, 3-glycidoxypropyltrimethoxy Silane, 3-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, epoxy group-containing oligomeric silane coupling agent, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxy propyltriethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltriethoxysilane, p-styryltrimethoxysilane, vinyl Examples include trimethoxysilane and vinyltriethoxysilane.

Among them, the functional group in the present coupling agent is more preferably a benzotriazole group or an epoxy group. That is, the coupling agent is more preferably at least one selected from benzotriazole-functional silane coupling agents and epoxy-functional silane coupling agents.
Commercially available products can also be used as the present coupling agent, such as "X-12-1214A", "X-12-981S", "X-12-984S", and "KBM-303" manufactured by Shin-Etsu Chemical Co., Ltd. , "KBM-402", "KBE-402", "KBM-403", "KBE-403", "X-12-967C", "KBM-1403", and "KBM-4803" (all trade names). be done.

The method of producing the present inorganic particles by surface-treating the hydrophobic inorganic particles with the present coupling agent includes a method of mixing a solution containing the present coupling agent and the hydrophobic inorganic particles. In particular, as a method for producing the present inorganic particles, it is preferable to subject hydrophobic inorganic particles to a shearing treatment in a solution containing the present coupling agent. By such a method, the present inorganic particles can be formed by the mechanism of action described above, and it is believed that the affinity with the F polymer is enhanced.
The shearing treatment is preferably carried out by mixing in a tank equipped with a thin film swirl agitation mechanism or a rotation and revolution agitation mechanism.
A thin-film swirling high-speed mixer is an example of a tank equipped with a stirring mechanism using thin-film swirling. A thin-film swirling high-speed mixer spreads a solution containing hydrophobic inorganic particles and the coupling agent into a thin film on the inner wall of a cylindrical stirring vessel, swirls, and mixes while applying centrifugal force. It is a device.
Further, examples of the tank equipped with a stirring mechanism by rotation and revolution include a planetary mixer and a rotation/revolution stirrer. A planetary mixer is a stirring device having two stirring blades that rotate and revolve with each other.
In the shearing treatment, the mixture of the solution containing the coupling agent and the hydrophobic inorganic particles may be heated to promote the reaction of the coupling agent, preferably under heating and reflux conditions. A reaction catalyst may also accelerate the reaction of the coupling agent.

The solvent for the solution containing the coupling agent is preferably alcohol. As the alcohol, methanol, ethanol, isopropanol, butanol, etc. having a boiling point in the range of 50° C. to 200° C. at atmospheric pressure are preferred, and methanol or ethanol is more preferred.
The solvent is removed from the solution after the shearing treatment, and if necessary, it is further dried to obtain the present inorganic particles. A known method such as filtration or centrifugation can be applied to remove the solvent from the solution. Drying can be performed by a known drying means such as an oven or a ventilation drying oven at a temperature higher than the boiling point of the solvent for 10 to 300 minutes. Drying can be carried out under normal pressure or reduced pressure, and may be carried out in an atmosphere of air or an inert gas such as helium gas, neon gas, argon gas, or nitrogen gas.
Further, after drying, the present inorganic particles may be obtained by pulverizing the hydrophobic inorganic particles surface-treated with the present coupling agent, or may be classified to obtain the present inorganic particles.

The content of F particles in the present composition is preferably 10% by mass or more, more preferably 20% by mass or more. The content of F particles is preferably 50% by mass or less.
The content of the present inorganic particles in the present composition is preferably 10% by mass or more, more preferably 20% by mass or more. The content of the present inorganic particles is preferably 70% by mass or less, more preferably 60% by mass or less.
The content ratio (mass ratio) of the present inorganic particles to the content of the F particles in the present composition is preferably 0.5 or more, more preferably 1.0 or more, and still more preferably more than 1. The above ratio is preferably 3 or less, more preferably 2 or less.
When the content and content ratio of the F particles and the present inorganic particles are within such ranges, the present composition tends to have excellent dispersibility due to the mechanism of action described above. In addition, a molded article having a low coefficient of linear expansion, a low dielectric constant and a low dielectric loss tangent, and excellent adhesiveness to a substrate, thermal conductivity and heat dissipation can easily be obtained from the present composition.

The present composition may further contain other inorganic particles different from the present inorganic particles as long as the effects of the present invention are not impaired. The shape of the other inorganic particles may be spherical, acicular, fibrous or plate-like. Other inorganic particles include carbon fiber, glass, boron nitride, aluminum nitride, beryllia, silica, wollastonite, talc, cerium oxide, aluminum oxide, magnesium oxide, zinc oxide or titanium oxide.
When the present composition further contains other inorganic particles different from the present inorganic particles, the content thereof is preferably 1 to 20% by mass or less with respect to the entire composition.

The composition may further contain other resins different from the tetrafluoroethylene-based polymer. Such other resins may be contained as particles in the present composition, or may be dissolved or dispersed in the liquid dispersion medium when the present composition contains a liquid dispersion medium described later.
Other resins include polyester resins such as liquid crystalline aromatic polyesters, polyimide resins, polyamideimide resins, epoxy resins, maleimide resins, urethane resins, polyphenylene ether resins, polyphenylene oxide resins, and polyphenylene sulfide resins.
The other resin is preferably an aromatic polymer, more preferably at least one aromatic imide polymer selected from the group consisting of aromatic polyimides, aromatic polyamic acids, aromatic polyamideimides, and aromatic polyamideimide precursors. . The aromatic polymer is preferably included in the composition as a varnish dissolved in a liquid carrier medium.
When the present composition further contains other resins, the content thereof is preferably 0.1 to 5% by mass or less based on the total composition.

The present composition may be in the form of a powder, a liquid containing a liquid dispersion medium (dispersion, slurry), or a paste. Alternatively, the present composition in powder form may be further melted to form the present composition in pellet form.
The liquid dispersion medium is preferably a compound that is liquid at 25°C under atmospheric pressure and has a boiling point of 50 to 240°C. One type of liquid dispersion medium may be used, or two or more types may be used. When two liquid dispersion media are used, the two liquid dispersion media are preferably compatible with each other.

The liquid dispersion medium is preferably a compound selected from the group consisting of water, amides, ketones and esters.
Amides include N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropanamide, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy- N,N-dimethylpropanamide, N,N-diethylformamide, hexamethylphosphorictriamide, 1,3-dimethyl-2-imidazolidinone.
Ketones include acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl n-pentyl ketone, methyl isopentyl ketone, 2-heptanone, cyclopentanone, cyclohexanone, cycloheptanone.
Esters include methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, ethyl 3-ethoxypropionate, γ-butyrolactone, γ- Valerolactone can be mentioned.

When the present composition contains a liquid dispersion medium, the content of the liquid dispersion medium is preferably 10 to 70% by mass or more based on the entire composition.
When the present composition contains a liquid dispersion medium, the solid content concentration in the present composition is preferably 30% by mass or more, more preferably 40% by mass or more. The solid content concentration is preferably 90% by mass or less, more preferably 60% by mass or less.
In addition, solid content means the total amount of the substance which forms solid content in the molding formed from this composition. Specifically, the F particles and the present inorganic particles are solid content, and when the present composition contains other resins or other inorganic particles, these other resins or other inorganic particles are also solid content, The total mass ratio of these components is the solid content concentration in the present composition.

When the present composition contains a liquid dispersion medium, the present composition preferably further contains a surfactant from the viewpoint of improving dispersion stability. Such surfactants are preferably nonionic surfactants.
Specific examples of nonionic surfactants include "Futergent" series (manufactured by Neos), "Surflon" series (manufactured by AGC Seimi Chemical), "Megafac" series (manufactured by DIC), "Unidyne" series (manufactured by DIC). Daikin Industries, Ltd.), “BYK-347”, “BYK-349”, “BYK-378”, “BYK-3450”, “BYK-3451”, “BYK-3455”, “BYK-3456” (BYK-Chemie Japan), “KF-6011”, “KF-6043” (manufactured by Shin-Etsu Chemical Co., Ltd.), “Tergitol” series (manufactured by Dow Chemical Co., Ltd., “Tergitol TMN-100X”, etc.).
When the present composition contains a nonionic surfactant, the content of the nonionic surfactant in the present composition is preferably 0.1 to 10% by mass based on the entire present composition.

The composition may further contain a silane coupling agent, if desired. Examples of the silane coupling agent include the same silane coupling agents that may be used for surface treatment of hydrophobic inorganic particles. When the present composition contains a silane coupling agent, the content of the silane coupling agent in the present composition is preferably 0.1 to 10% by mass based on the entire present composition.

The present composition further contains a thixotropic agent, a viscosity modifier, an antifoaming agent, a dehydrating agent, a plasticizer, a weathering agent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a brightener, a colorant, Additives such as a conductive agent, a mold release agent, a surface treatment agent other than the silane coupling agent described above, and a flame retardant may be contained.

When the present composition contains a liquid dispersion medium and is liquid, the viscosity thereof is preferably 10 mPa·s or more, more preferably 100 mPa·s or more. The viscosity of the present composition is preferably 10000 mPa·s or less, more preferably 3000 mPa·s or less.
When the present composition contains a liquid dispersion medium and is liquid, its thixotropic ratio is preferably 1.0 to 3.0.
When the present composition contains water as a liquid dispersion medium, its pH is more preferably 8 to 10 from the viewpoint of improving long-term storage stability. The pH of the present composition can be controlled by adding a pH adjuster (amine, ammonia, citric acid, etc.) or a pH buffer (tris(hydroxymethyl)aminomethane, ethylenediaminetetraacetic acid, ammonium hydrogencarbonate, ammonium carbonate, ammonium acetate, etc.). can be adjusted by

The present composition is obtained by mixing the F particles, the present inorganic particles, and, if necessary, other resins, other inorganic particles, liquid dispersion media, surfactants, silane coupling agents, additives, and the like.
The present composition may be obtained by mixing the F particles and the present inorganic particles all at once, or may be obtained by separately sequentially mixing them, or by preparing a masterbatch of these in advance and mixing it with the remaining ingredients. may The order of mixing is not particularly limited, and the method of mixing may be batch mixing or mixing in multiple batches.
Mixing devices for obtaining the present composition include stirring devices equipped with blades such as Henschel mixers, pressure kneaders, Banbury mixers and planetary mixers, ball mills, attritors, basket mills, sand mills, sand grinders, dyno mills, Dispermat, SC mill, spike mill, and agitator mill equipped with media, microfluidizer, nanomizer, ultimizer, ultrasonic homogenizer, dissolver, disper, high-speed impeller, thin-film swirling high-speed mixer, rotation-revolution agitator and dispersing devices with other mechanisms such as V-type mixers.

As a suitable method for producing the present composition containing a liquid dispersion medium, the F particles, the present inorganic particles, and a part of the liquid dispersion medium are kneaded in advance to obtain a kneaded product, and the kneaded product is added to the remaining A production method of obtaining the present composition by adding it to a liquid dispersion medium can be exemplified. The liquid dispersion medium used for kneading and addition may be the same type of liquid dispersion medium or different types of liquid dispersion mediums. Other resins, other inorganic particles, surfactants, silane coupling agents, and additives may be mixed during kneading or may be mixed during addition. Mixing in kneading is preferably carried out using a planetary mixer or a rotation-revolution stirrer.

The kneaded product obtained by kneading may be in the form of a paste (such as a paste having a viscosity of 1,000 to 100,000 mPa s), or in the form of a wet powder (wet powder having a viscosity of 10,000 to 100,000 Pa s as measured by a capillograph. (dough), etc.).
The viscosity measured by the capillograph is defined by using a capillary with a capillary length of 10 mm and a capillary radius of 1 mm, a furnace body diameter of 9.55 mm, a load cell capacity of 2 t, a temperature of 25 ° C., and a shear rate of It is a value measured as 1s ⁻¹ .

A molded product such as a sheet can be obtained by subjecting the composition to a molding method such as extrusion.
When the composition contains a liquid dispersion medium and is liquid, it is preferred to extrude the composition into a sheet. The sheet obtained by extrusion may be further subjected to press molding, calender molding, or the like, and cast. The sheet is preferably further heated to remove the liquid dispersion medium and calcine the F polymer.
If the composition is in powder form, it is preferred to melt extrude the composition. Extrusion can be carried out using a single-screw extruder, a multi-screw extruder, or the like.
In addition, the present composition may be injection molded to obtain a molded product.
When forming a molded article, the present composition may be directly melt-extruded or injection-molded. The composition is melt-kneaded to form pellets, and the pellets are melt-extruded or injection-molded to form articles such as sheets. may be obtained.

The thickness of the sheet obtained from this composition is preferably 1 µm or more, more preferably 10 µm or more, and even more preferably 25 µm or more. The thickness of the sheet is preferably 200 μm or less, more preferably 100 μm or less.
The coefficient of linear expansion of the sheet is preferably 100 ppm/°C or less, more preferably 80 ppm/°C or less. The lower limit of the linear expansion coefficient of the sheet is 30 ppm/°C. The coefficient of linear expansion means the value obtained by measuring the coefficient of linear expansion of the test piece in the range of 25° C. or more and 260° C. or less according to the measurement method specified in JIS C 6471:1995.
The thermal conductivity in the in-plane direction of the sheet is preferably 1.0 W/m·K or more, more preferably 3.0 W/m·K or more. The upper limit of the sheet thermal conductivity is 20 W/m·K.

A laminate can be formed by laminating such a sheet on a substrate. As a method for producing a laminate, a co-extruder is used as the extruder, a method of extruding the present composition together with the raw material of the substrate, a method of extruding the present composition on the substrate, a method of extruding the sheet and the substrate A method of thermocompression bonding the material and the like can be mentioned.
As the base material, metal substrates (copper, nickel, aluminum, titanium, metal foils of their alloys, etc.), heat-resistant resin films (polyimide, polyamide, polyetheramide, polyphenylene sulfide, polyaryletherketone, polyamideimide, Liquid crystalline polyester, heat-resistant resin film such as tetrafluoroethylene polymer), prepreg substrate (precursor of fiber reinforced resin substrate), ceramic substrate (ceramic substrate such as silicon carbide, aluminum nitride, silicon nitride), glass substrate be done.

Examples of the shape of the substrate include planar, curved, and uneven shapes. Moreover, the shape of the substrate may be any of foil, plate, film, and fiber.
The ten-point average roughness of the substrate surface is preferably 0.01 to 0.05 μm.
The surface of the substrate may be surface-treated with a silane coupling agent or plasma-treated. Examples of such silane coupling agents include 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3 - Silane coupling agents with functional groups such as isocyanatopropyltriethoxysilane are preferred.
The peel strength between the sheet and the substrate is preferably 2 kN/m or more, more preferably 2.5 kN/m or more. The peel strength is preferably 10 kN/m or less.

By disposing the present composition on the surface of a substrate to form a polymer layer containing the F polymer and the present inorganic particles, a laminate having a substrate layer composed of the substrate and a polymer layer can be obtained.
The polymer layer is preferably formed by disposing the present composition containing a liquid dispersion medium on the surface of a substrate, removing the dispersion medium by heating, and baking the F polymer by further heating.
Examples of the base material include those similar to the base material that can be laminated with the sheet described above, and preferred embodiments thereof are also the same.

Examples of the method for disposing the present composition include a coating method, a droplet discharge method, and an immersion method, and roll coating, knife coating, bar coating, die coating, and spraying are preferred.
Heating for removing the liquid dispersion medium is preferably carried out at 100 to 200° C. for 0.1 to 30 minutes. In this heating, the liquid dispersion medium does not have to be completely removed, and may be removed to such an extent that the layer formed by the packing of the F particles and the present inorganic particles can maintain a self-supporting film. Also, during the heating, air may be blown to facilitate the removal of the liquid dispersion medium by air-drying.
Heating for sintering the F polymer is preferably performed at a temperature equal to or higher than the sintering temperature of the F polymer, and more preferably at 360 to 400° C. for 0.1 to 30 minutes.
A heating apparatus for each heating includes an oven and a ventilation drying oven. The heat source in the apparatus may be a contact heat source (hot air, hot plate, etc.) or a non-contact heat source (infrared radiation, etc.).
Further, each heating may be performed under normal pressure or under reduced pressure.
Moreover, the atmosphere in each heating may be either an air atmosphere or an inert gas (helium gas, neon gas, argon gas, nitrogen gas, etc.) atmosphere.

The polymer layer is formed through the steps of disposing the present composition and heating. These steps may be performed once each, or may be repeated twice or more. For example, the present composition may be placed on the surface of a substrate and heated to form a polymer layer, and further the present composition may be placed on the surface of the polymer layer and heated to form a second polymer layer. . In addition, at the stage where the present composition is placed on the surface of the substrate and heated to remove the liquid dispersion medium, the present composition may be further placed on the surface and heated to form a polymer layer.
The composition may be placed on only one surface of the substrate or may be placed on both sides of the substrate. In the former case, a laminate having a base layer and a polymer layer on one surface of the base layer is obtained, and in the latter case, a base layer and a polymer layer are obtained on both surfaces of the base layer. A laminate is obtained.

Preferred specific examples of the laminate include a metal foil and a metal-clad laminate having a polymer layer on at least one surface of the metal foil, a polyimide film, and a multilayer film having a polymer layer on both surfaces of the polyimide film. is mentioned.
The thickness of the polymer layer, the dielectric constant, the dielectric loss tangent, the coefficient of linear expansion, the thermal conductivity in the in-plane direction, and the preferred ranges of the peel strength between the polymer layer and the substrate layer are as follows in the sheet obtained from the above composition: The thickness, dielectric constant, dielectric loss tangent, coefficient of linear expansion, thermal conductivity in the in-plane direction, and the preferred range of peel strength between the sheet and the substrate are the same.

The composition is useful as a material for imparting insulation, heat resistance, corrosion resistance, chemical resistance, water resistance, impact resistance, and thermal conductivity.
Specifically, the present composition can be used for printed wiring boards, thermal interface materials, substrates for power modules, coils used in power devices such as motors, automotive engines, heat exchangers, vials, syringes, Ampoules, medical wires, secondary batteries such as lithium ion batteries, primary batteries such as lithium batteries, radical batteries, solar cells, fuel cells, lithium ion capacitors, hybrid capacitors, capacitors, capacitors (aluminum electrolytic capacitors, tantalum electrolytic capacitors, etc.) ), electrochromic elements, electrochemical switching elements, electrode binders, electrode separators, and electrodes (positive and negative electrodes).
The composition is also useful as an adhesive to bond parts together. Specifically, the composition can be used for adhesion of ceramic parts, adhesion of metal parts, adhesion of electronic parts such as IC chips, resistors and capacitors on substrates of semiconductor elements and module parts, adhesion of circuit boards and heat sinks, LED It can be used for bonding chips to substrates.
In addition, the present composition can also be suitably used in applications requiring electrical conductivity, such as the field of printed electronics. Specifically, it can be used to manufacture energization elements in printed circuit boards, sensor electrodes, and the like.

Molded articles, sheets and laminates formed from the present composition are useful as antenna parts, printed circuit boards, aircraft parts, automobile parts, sporting goods, food products, heat dissipation parts, paints, cosmetics and the like.
Specifically, electric wire coating materials (wires for aircraft, etc.), enameled wire coating materials used for motors such as electric vehicles, electrical insulating tapes, insulating tapes for oil drilling, oil transportation hoses, hydrogen tanks, printed circuit boards materials, separation membranes (microfiltration membranes, ultrafiltration membranes, reverse osmosis membranes, ion exchange membranes, dialysis membranes, gas separation membranes, etc.), electrode binders (for lithium secondary batteries, fuel cells, etc.), copy rolls, Furniture, automobile dashboards, home appliance covers, sliding parts (load bearings, yaw bearings, slide shafts, valves, bearings, bushes, seals, thrust washers, wear rings, pistons, slide switches, gears, cams, belt conveyors , food conveyor belts, etc.), tension ropes, wear pads, wear strips, tube ramps, test sockets, wafer guides, wear parts for centrifugal pumps, chemical and water supply pumps, tools (shovels, files, awls, saws, etc.), Boilers, hoppers, pipes, ovens, baking molds, chutes, racket guts, dies, toilet bowls, container coverings, mounting heat dissipation substrates for power devices, heat dissipation materials for wireless communication devices, transistors, thyristors, rectifiers, transformers, power MOS FETs , CPUs, heat radiating fins, metal heat radiating plates, blades for wind turbines, wind power generation equipment, aircraft, etc., PC and display housings, electronic device materials, interior and exterior of automobiles, processing machines and vacuum ovens that heat under low oxygen conditions, It is useful as a sealing material for plasma processing equipment, heat radiation components in processing units such as sputtering and various dry etching equipment, and electromagnetic wave shields.

Molded articles, sheets and laminates formed from the present composition are particularly suitable for electronic applications such as flexible printed wiring boards for car electronics such as LED headlamps, power control units or electric control units, rigid printed wiring boards and the like. It is useful as a substrate material such as a heat dissipation sheet, a heat dissipation substrate, and a heat dissipation substrate for automobiles.
When using the molded article, sheet or laminate formed from the present composition as a heat dissipating member, the molded article, sheet or laminate may be directly adhered to a target substrate, or may be coated with a silicone adhesive layer or the like. may be attached to the target substrate via the adhesive layer.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these.
1. Preparation of each component [F polymer]
F particle 1: 97.9 mol%, 0.1 mol% and 2.0 mol% of TFE units, NAH units and PPVE units in this order, and a carbonyl group-containing group per 1 × 10 ⁶ main chain carbon atoms Particles (D50: 2.1 μm, non-hollow) of tetrafluoroethylene-based polymer (melting temperature: 300° C.) having 1000 particles
[Hydrophobic inorganic particles]
Inorganic particles 1: plate-like boron nitride particles (hexagonal system, average particle size (D50) 11 μm)
[Coupling agent]
Coupling agent 1: "X-12-1214A" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., N-(trimethoxysilyl-propyl)-1H-benzotriazole-1-carbodiamide; trimethoxysilyl group and benzotriazole group is bonded via a linking group containing a carbodiimide bond)
Coupling agent 2: "X-12-984S" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., a compound in which a triethoxysilyl group and a glycidyl ether group are bonded via a linking group containing a urethane bond)
Coupling agent 3: “KBM-904” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycoxidopropyltrimethoxysilane)
[Liquid dispersion medium]
NMP: N-methyl-2-pyrrolidone

2. Production example of composition [Example 1]
A methanol solution containing coupling agent 1 and inorganic particles 1 were sheared for 5 hours using a planetary mixer while being heated under reflux at 80°C. After the contents were filtered, the filtrate was dried to obtain inorganic particles 1 surface-treated with coupling agent 1 (hereinafter referred to as “BN-T ₁₁ ”).
BN-T ₁₁ (22 parts by mass) obtained above, F particles 1 (11 parts by mass) and NMP (20 parts by mass) are kneaded in a rotation or revolution stirrer to obtain a wet powder-like dough 1, and NMP (47 parts by mass) was added and stirred to obtain composition 1 as a dispersion.

[Example 2]
Inorganic particles 1 surface-treated with coupling agent 2 (hereinafter referred to as "BN-T ₂₁ ), and in the same manner as in Example 1, Composition 2, which is a dispersion containing BN-T ₂₁ , F particles 1 and NMP, was obtained.
[Example 3]
Inorganic particles 1 surface-treated with coupling agent 3 (hereinafter, “BN-T ₃₁ ), and in the same manner as in Example 1, Composition 3, which is a dispersion containing BN-T ₃₁ , F particles 1 and NMP, was obtained.

[Example 4]
Inorganic particles 1 (22 parts by mass), F particles 1 (11 parts by mass) and NMP (20 parts by mass) are kneaded in a rotation or revolution stirrer to obtain a wet powder-like dough, and NMP (47 parts by mass). was added and stirred to obtain composition 4 as a dispersion.
[Example 5]
F particles 1 (15 parts by mass) and NMP (25 parts by mass) are kneaded in a rotation or revolution stirrer to obtain a wet powder-like dough, and NMP (60 parts by mass) is added and stirred to obtain a dispersion liquid. A composition 5 was obtained.

3. Evaluation of Dispersion Stability of Composition After each composition was stored in a container at 25° C., its dispersibility was visually confirmed, and dispersion stability was evaluated according to the following criteria.
[Evaluation criteria]
◯: Aggregate is not visually recognized.
Δ: Sedimentation of aggregates was also visually observed at the bottom of the container, but re-dispersion was easy.
x: Aggregates were also visually observed at the bottom of the container, and redispersion was difficult.
From the standpoint of dispersion stability, composition 3 was not subjected to the production and evaluation of the laminate described below.

4. Production Example of Laminate The composition 1 was applied to the surface of a long copper foil using a bar coater to form a wet film. Then, the copper foil on which the wet film was formed was passed through a drying furnace at 110° C. for 5 minutes to dry it, thereby forming a dry film. The copper foil with dry film was then heated in a nitrogen oven at 380° C. for 3 minutes. Thus, a laminate 1 having a copper foil and a polymer layer having a thickness of 50 μm containing the fused and sintered F particles 1 and BN-T ₁₁ on its surface was produced.
Laminates 2, 4 and 5 were prepared from compositions 2, 4 and 5 in the same manner as laminate 1.

5. Evaluation of laminate 5-1. Evaluation of Thermal Conductivity of Laminate For each laminate, the copper foil of the laminate was removed by etching with an aqueous ferric chloride solution to prepare a sheet as a single polymer layer. A 10 mm×10 mm square test piece was cut out from the center of the prepared sheet, and the thermal conductivity (W/m·K) in the in-plane direction was measured and evaluated according to the following criteria.
[Evaluation criteria]
○: More than 2 W/m・K △: 1 W/m・K or more and 2 W/m・K or less ×: Less than 1 W/m・K

5-2. Evaluation of Peel Strength of Laminate A rectangular test piece (length 100 mm, width 10 mm) was cut out from each laminate. Then, the copper foil and the polymer layer were separated from one longitudinal end of the test piece at a position 50 mm from one end in the longitudinal direction, and at a pulling speed of 50 mm/min at 90° to the test piece.
The maximum load applied at this time was measured as the peel strength (N/m) and evaluated according to the following criteria.
[Evaluation criteria]
○: 2 kN/m or more ×: less than 2 kN/m The above results are summarized in Table 1.

As is clear from the above results, the present composition has excellent dispersion stability, and the laminate formed from the present composition exhibits the physical properties of the F polymer and the inorganic particles at a high level, and has excellent adhesion to the substrate and thermal conductivity. Excellent heat dissipation.

Claims (15)

It contains a tetrafluoroethylene-based polymer and hydrophobic inorganic particles surface-treated with a coupling agent. A composition that is a compound that is linked via a linking group that includes any one or more selected from a bond and a carbodiimide bond. The composition according to claim 1, wherein the tetrafluoroethylene-based polymer is a hot-melt tetrafluoroethylene-based polymer having a melting temperature of 180°C or higher. The composition according to claim 1 or 2, wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having an oxygen-containing polar group. The composition according to any one of claims 1 to 3, wherein the tetrafluoroethylene-based polymer is particulate. The composition according to any one of claims 1 to 4, wherein the inorganic particles have a surface hydroxyl group content of 50/ ^nm2 or less. The composition according to any one of claims 1 to 5, wherein the inorganic particles are at least one selected from the group consisting of alumina, cristobalite, boron nitride, magnesium oxide, mica, forsterite and cordierite. The composition according to any one of claims 1 to 6, wherein the inorganic particles have an average particle size of less than 15 µm. The composition according to any one of claims 1 to 7, wherein the coupling agent is at least one selected from benzotriazole-functional silane coupling agents and epoxy-functional silane coupling agents. The composition according to any one of claims 1 to 8, wherein the content ratio (mass ratio) of the inorganic particles to the tetrafluoroethylene-based polymer is greater than 1. The composition according to any one of claims 1 to 9, which is in liquid or powder form. A coupling agent that is a compound in which a trialkoxysilyl group and a functional group are bonded via a linking group containing one or more selected from an imino bond, an amide bond, a urea bond, a urethane bond, and a carbodiimide bond. The hydrophobic inorganic particles surface-treated with a coupling agent used in the composition according to any one of claims 1 to 10, wherein the hydrophobic inorganic particles are sheared in a solution containing Production method. 12. The method for producing inorganic particles according to claim 11, wherein the shearing treatment is carried out by mixing in a tank equipped with a thin film swirl agitation mechanism or a rotation and revolution agitation mechanism. A composition containing the tetrafluoroethylene-based polymer and the inorganic particles is obtained by mixing the tetrafluoroethylene-based polymer and the hydrophobic inorganic particles obtained by the production method of claim 11 or 12. A method for producing the composition according to any one of 1 to 10. The composition according to any one of claims 1 to 10 is applied to the surface of a substrate and heated to form a polymer layer containing the tetrafluoroethylene-based polymer and the inorganic particles, and the substrate A method for producing a laminate, which obtains a laminate having a base layer composed of and the polymer layer. A laminate comprising a substrate layer and a polymer layer containing the tetrafluoroethylene-based polymer and the inorganic particles, formed from the composition according to any one of claims 1 to 10.