TW202106730A - Dispersion solution and molded product - Google Patents

Abstract

Provided is a dispersion solution that is excellent in terms of physical properties (dispersibility and coatability) of the solution itself and that can readily be molded into a molded product that is excellent in terms of heat conductivity, scratch resistance, electric properties, and the like; also provided is a molded product that is excellent in terms of heat conductivity, scratch resistance, electric properties, and the like. This dispersion solution contains a thermoplastic tetrafluoroethylene-based polymer powder having a melting temperature of 200 to 300 DEG C, a metal oxide filler containing over 50% by mass of metal oxide, a silicon oxide filler containing over 50% by mass of silicon oxide, and a polar dispersion medium in liquid form. The content of the metal oxide filler contained in the dispersion solution is 5% by mass or higher.

Description

Dispersion and molding

The present invention relates to a dispersion containing a tetrafluoroethylene polymer, a metal oxide filler, and a silica filler, and a molded product thereof.

Tetrafluoroethylene polymers such as polytetrafluoroethylene (PTFE) have excellent chemical resistance, water and oil repellency, heat resistance, electrical properties and other physical properties, and a dispersion containing its powder is used as a substrate coated with a tetrafluoroethylene polymer layer The surface material is more useful.

The dispersion liquid must be excellent in the physical properties of the liquid itself and the physical properties of the layer formed by it. Furthermore, in recent years, in the use of coating the surface of a metal substrate or the like, it is required to further improve the layer adhesion, thermal conductivity (heat dissipation), scratch resistance, and electrical characteristics of the latter physical properties. As a dispersion liquid suitable for this use, a dispersion liquid containing a tetrafluoroethylene-based polymer powder and a metal oxide filler has been proposed (refer to Patent Documents 1 to 3). Prior art literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. 2017-110220 Patent Document 2: Japanese Patent Laid-Open No. 2018-059032 Patent Document 3: International Publication No. 2018/110644

[The problem to be solved by the invention]

However, it is difficult to prepare a dispersion liquid containing a tetrafluoroethylene-based polymer powder that can easily form a layer with excellent physical properties while maintaining the physical properties of the liquid itself. The content of the metal oxide filler in the dispersion of Patent Documents 1 and 2 is restricted by the state of the dispersion medium and the particle size of the metal oxide filler, or the dispersibility of the dispersion is reduced (for example, refer to paragraph No. [0050] in Patent Document 1. ] Table 1, paragraph number [0054] Table 5). As a result, there is a problem in that the state of the dispersion is limited, and it is difficult to form a layer with excellent thermal conductivity, adhesiveness, and adhesiveness, and in particular, it is difficult to form a layer with excellent thermal conductivity (heat dissipation). Since the dispersion of Patent Document 3 contains a large amount of polymers other than the tetrafluoroethylene-based polymer (a water-soluble acrylic polymer containing sulfonic acid groups, etc.) as a contiguous component, it is difficult to adequately express the tetrafluoroethylene in the formed layer. Problems with the physical properties (durability and weather resistance, etc.) of ethylene-based polymers. The inventors conducted intensive research and found that by combining specific tetrafluoroethylene-based polymers with specific fillers, it is possible to easily form a layer having the physical properties of each filler and the physical properties of the tetrafluoroethylene-based polymer easily. The dispersion. [Technical means to solve the problem]

The present invention has the following aspects. [1] A dispersion liquid comprising: tetrafluoroethylene-based polymer powder having a melting temperature of 200-320°C and having thermoplasticity; a metal oxide filler containing more than 50% by mass of metal oxide; a silica filler, It contains more than 50% by mass of silica; and a polar liquid dispersion medium; the content of the above-mentioned metal oxide filler is more than 5% by mass. [2] The dispersion liquid of [1], wherein the tetrafluoroethylene-based polymer is at least one polymer selected from the group consisting of the following polymers: containing tetrafluoroethylene-based units and based on oxygen-containing polarity Tetrafluoroethylene-based units and perfluoro(propyl vinyl ether)-based polymers containing 2 mol% or more of tetrafluoroethylene-based units, and tetrafluoroethylene-based units and polymers based on A polymer of perfluoro (methyl vinyl ether) units. [3] The dispersion liquid of [1] or [2], wherein the metal oxide is at least one metal oxide selected from the group consisting of the following metal oxides: aluminum oxide, lead oxide, iron oxide, oxide Tin, magnesium oxide, titanium oxide, zinc oxide, antimony pentoxide, zirconium oxide, lanthanum oxide, neodymium oxide, cerium oxide and niobium oxide. [4] The dispersion liquid according to any one of [1] to [3], wherein the metal oxide filler further contains silicon oxide. [5] The dispersion liquid according to any one of [1] to [4], wherein the metal oxide filler is a filler having a particle shape and an average particle size greater than the average particle size of the powder, or a fibrous and average fiber A filler whose length is greater than the average particle size of the above-mentioned powder. [6] The dispersion liquid according to any one of [1] to [5], wherein the shape of the silica filler is spherical or scaly. [7] The dispersion liquid of any one of [1] to [6], wherein the structure of the silica filler is hollow. [8] The dispersion liquid according to any one of [1] to [7], wherein the mass ratio of the content of the silica filler to the content of the metal oxide filler is less than 1. [9] The dispersion liquid of any one of [1] to [8] has a viscosity of 10000 mPa·s or less at 25°C. [10] The dispersion liquid of any one of [1] to [9] has a thixotropic ratio of 1.0 to 2.5 at 25°C. [11] A method for producing a laminate, comprising applying the dispersion liquid of any one of [1] to [10] to a substrate layer, heating to volatilize the liquid dispersion medium, and further heating to make the tetrafluoroethylene The system polymer is fired to obtain a laminate having the above-mentioned base material layer and a polymer layer containing the above-mentioned tetrafluoroethylene-based polymer, the above-mentioned metal oxide filler, and the above-mentioned silica filler. [12] A molded article comprising: a tetrafluoroethylene-based polymer having a melting temperature of 200 to 320°C and having thermoplasticity; a metal oxide filler containing more than 50% by mass of a metal oxide; a silica filler, which Containing more than 50% by mass of silica; the content of the tetrafluoroethylene-based polymer is more than 50% by mass, and the sum of the content of the metal oxide filler and the content of the silica filler is more than 10% by mass. [13] The molded article as in [12] has a thickness of 1 to 1000 μm. [14] The formed article as [12] or [13] has a thermal conductivity of 1 W/mK or more. [15] The molded article of any one of [12] to [14] has a dielectric loss tangent of 0.005 or less. [Effects of Invention]

According to the present invention, it is possible to obtain a dispersion, a laminate, and a molded product. The dispersion liquid itself has good physical properties (dispersibility and coating properties), and can easily form excellent thermal conductivity, scratch resistance, electrical properties, etc. The polymer layer, the laminate and the molded article have the above-mentioned polymer layer.

The meanings of the following terms are as follows. "Polymer melt viscosity" is based on ASTM D1238, using a rheometer and a 2Φ-8L die, a sample (2 g) of the polymer that has been heated at the measurement temperature for 5 minutes in advance under a load of 0.7 MPa Keep the value measured at the measured temperature. The "melting temperature (melting point) of the polymer" is the temperature corresponding to the maximum value of the melting peak of the polymer measured by the differential scanning calorimetry (DSC, Differential Scanning Calorimetry) method. "Powder average particle size (D50)" is the cumulative 50% diameter of the powder based on the volume of the powder obtained by laser diffraction and scattering methods. That is, the particle size distribution of the powder is measured by laser diffraction and scattering methods, and the total volume of the clusters of the powder particles is 100%, and the cumulative curve is calculated. The cumulative volume on the cumulative curve is 50%. Particle size. "Powder D90" is the cumulative 90% diameter of the powder measured in the same way. The D50 and D90 of the powder are obtained by dispersing the powder in water and analyzing it by the laser diffraction-scattering method using a laser diffraction and scattering particle size distribution measuring device (LA-920 measuring device manufactured by Horiba Manufacturing Co., Ltd.) . "Viscosity of dispersion" is the value measured at room temperature (25°C) with a rotation speed of 30 rpm using a type B viscometer. Repeat the measurement 3 times and take the average of the 3 measurements. "Thixotropic dispersion ratio" so-called, refers to the speed of the viscosity measured at 60 rpm to obtain the condition η ₂ is the measured speed is divided by the viscosity at 30 rpm of the condition η ₁ of the calculated value. Repeat the viscosity measurement of each 3 times, and take the average of the 3 measurements. "Ten-point average roughness (Rzjis)" is the value specified by the appendix JA of JIS B 0601:2013. The so-called "peel strength" refers to the length of the laminated body cut into a rectangular shape (length 100 mm, width 10 mm) fixed at a position of 50 mm at one end of the length direction, and a stretching speed of 50 mm/min from one end of the length direction The maximum load (N/cm) applied when the polymer layer is peeled from the substrate (aluminum foil) at 90° with respect to the laminate. "The thermal conductivity of the molded article" is the value measured in accordance with ASTM D5470. The "unit" of a polymer can be an atomic group directly formed from a monomer by polymerization reaction, or it can be an atomic group after a part of the structure is transformed by processing the polymer obtained by polymerization reaction by a specific method. The monomer A-based unit contained in the polymer is also simply referred to as "monomer A unit". "(Meth)acrylate" is a collective term for acrylate and methacrylate.

The dispersion of the present invention contains: tetrafluoroethylene polymer (hereinafter also referred to as "F polymer") powder (hereinafter also referred to as "F powder"), which has a melting temperature of 200 to 300°C and has thermoplasticity; metal oxidation Material filler (hereinafter also referred to as "MO filler"), which contains more than 50% by mass of metal oxide; silica filler (hereinafter also referred to as "SO filler"), which contains more than 50% by mass of silica; and polar Liquid dispersion medium. The content of the MO filler contained in the dispersion of the present invention is 5% by mass or more. The dispersion of the present invention is a dispersion formed by dispersing each of F powder, MO filler and SO filler.

The dispersion of the present invention has excellent dispersibility and can easily form a compact F polymer formed with a high degree of dispersion of MO filler and SO filler (in addition to coating film, film, but also polymer formed on the surface of the substrate Layers and other aspects; the following is the same). The reason is not necessarily clear, but it is considered as follows: because the F polymer has specific physical properties, the F powder is excellent in dispersibility, and the F powder is highly fluid when the layer is formed, thereby promoting the homogeneous distribution of the filler in the layer. In addition, it is believed that the silicon oxide contained in the SO filler not only improves the physical properties of the layer (reduction of linear expansion, improvement of electrical properties, etc.), the homogeneous distribution and orientation of the MO filler are also improved. As a result, it is presumed that in the molded product, the MO filler and the SO filler are uniformly and firmly held in the matrix formed of the F polymer, and various physical properties are favorably imparted to the molded product. The above effects are more prominently manifested in the following preferred aspects of the present invention.

The D50 of the F powder of the present invention is preferably 40 μm or less, more preferably 20 μm or less, and particularly preferably 8 μm or less. The D50 of the F powder is preferably 0.01 μm or more, more preferably 0.1 μm or more, and particularly preferably 1 μm or more. In addition, the D90 of the F powder is preferably 80 μm or less, and more preferably 50 μm or less. When D50 and D90 are in this range, the fluidity and dispersibility of F powder are good, and the molded article is most likely to exhibit excellent electrical properties (low dielectric constant, low transmission loss, etc.), heat resistance, and scratch resistance. The bulk density of F powder is more preferably 0.08～0.5 g/mL. The densely packed bulk density of F powder is more preferably 0.1～0.8 g/mL. When the bulk density of the sparse filling or the bulk density of the dense filling is within the above range, the F powder has excellent properties.

The F powder of the present invention may also contain resins other than F polymer, but preferably contains F polymer as the main component. The content of the F polymer in the powder is preferably 80% by mass or more, more preferably 100% by mass. As said resin, heat resistant polymers, such as aromatic polyester, polyimide imide, thermoplastic polyimide, polyphenylene ether, polyphenylene ether, are mentioned.

The F polymer of the present invention is a thermoplastic polymer containing tetrafluoroethylene (TFE)-based units (hereinafter also referred to as "TFE units"). The melting temperature of the F polymer is preferably 200-320°C, 260-320°C. In this case, the filler is easily dispersed to a high degree when the molded article is formed, and the adhesiveness and surface flatness of the molded article are easily improved. The melt viscosity of the F polymer at 380°C is preferably 1×10 ² to 1×10 ⁶ Pa·s, more preferably 1×10 ³ to 1×10 ⁶ Pa·s.

As a preferable aspect of the F polymer, a polymer containing a TFE unit and a unit based on a monomer having an oxygen-containing polar group (hereinafter also referred to as "F polymer 1") can be cited. Since F polymer 1 has high dispersibility to the polar liquid dispersion medium and has a high affinity with each of the MO filler and SO filler, it highly interacts with the F polymer 1 and the liquid dispersion medium and is easy to be effective. It effectively inhibits the precipitation of F powder and the filler of the two in the dispersion. In addition, it is easy to have a fine spherulite structure on the surface. As a result, in the molded article formed from the dispersion, the filler of both is uniformly and firmly held in the matrix formed of the F polymer 1, and the molded article can be easily imparted with a metal oxide and silicon oxide based filler. Physical properties.

The oxygen-containing polar group of the F polymer 1 may be contained in the terminal part of the polymer main chain. In addition, it may be included in the polymer by surface treatment (radiation treatment, electron beam treatment, corona treatment, plasma treatment, etc.). In addition, the oxygen-containing polar group possessed by the F polymer 1 may also be a base prepared by modifying a polymer having a group capable of forming an oxygen-containing polar group. The oxygen-containing polar group contained in the polymer terminal group can be obtained by adjusting the components (polymerization initiator, chain transfer agent, etc.) used when the polymer is polymerized. The oxygen-containing polar group is a polar group containing oxygen atoms. However, the oxygen-containing polar group of the present invention does not contain the ester bond itself and the ether bond itself, but includes atomic groups having these bonds as characteristic groups.

The oxygen-containing polar group is preferably at least one group selected from the group consisting of a hydroxyl group, a carbonyl group-containing group, an acetal group and an alkylene oxide group, and more preferably: -CF ₂ CH ₂ OH, -C (CF ₃ ) ₂ OH, 1,2-diol group (-CH(OH)CH ₂ OH), acetal group, >C(O), -CF ₂ C(O)OH, >CFC(O)OH , Carboxyamido (-C(O)NH ₂ etc.), acid anhydride residues (-C(O)OC(O)-), imine residues (-C(O)NHC(O)- etc.) , Dicarboxylic acid residues (-CH(C(O)OH)CH ₂ C(O)OH, etc.), carbonate groups (-OC(O)O-), epoxy groups and oxetanyl groups, and Preferably it is an acid anhydride residue. In addition, from the viewpoint that it is difficult to damage the adhesion of the F powder, the oxygen-containing polar group is particularly preferably a polar group, a cyclic group or a cyclic acid anhydride residue or a cyclic imine residue of a cyclic group or its ring-opening group. The most preferred are cyclic anhydride groups, cyclic carbonate groups, cyclic acetal groups, 1,2-dicarboxylic acid residues, and 1,2-diol groups.

F polymer 1 is more preferably a polymer having the following units: TFE units, based on units of hexafluoropropylene, perfluoro(alkyl vinyl ether) (PAVE) or fluoroalkyl ethylene (FAE) (hereinafter also referred to as " PAE unit"), and a unit based on a monomer having an oxygen-containing polar group. Among all the units constituting F polymer 1, the ratio of TFE units, the ratio of PAE units, and the ratio of units based on the above monomers are preferably 50-99 mol%, 0-10 mol%, 0.01 ~3 mole%.

Examples of PAVE include: CF ₂ =CFOCF ₃ (PMVE), CF ₂ =CFOCF ₂ CF ₃ , CF ₂ =CFOCF ₂ CF ₂ CF ₃ (PPVE), CF ₂ =CFOCF ₂ CF ₂ CF ₂ CF ₃ , CF ₂ =CFO(CF ₂ ) ₈ F, preferably PMVE or PPVE. Examples of FAE include: CH ₂ =CH(CF ₂ ) ₂ F, CH ₂ =CH(CF ₂ ) ₃ F, CH ₂ =CH(CF ₂ ) ₄ F(PFBE), CH ₂ =CF(CF ₂ ) ₃ H, CH ₂ =CF(CF ₂ ) ₄ H. The PAE unit is preferably a PAVE-based unit.

The unit based on a monomer having an oxygen-containing polar group is preferably a unit based on a monomer having an acid anhydride residue, more preferably itaconic anhydride, citraconic anhydride, 5-nor 𦯉ene-2,3-dicarboxylic anhydride ( Hereinafter, it is also referred to as "NAH") or maleic anhydride, and NAH is more preferred. There may be one type of polar unit, or two or more types.

In addition, the F polymer 1 may further include other units. The other units may be one type or two or more types. Examples of monomers forming other units include ethylene, propylene, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, and chlorotrifluoroethylene.

As a preferable aspect of the F polymer, a polymer containing 2 mol% or more of TFE units and perfluoropropyl vinyl ether-based units (hereinafter also referred to as "PPVE units") (hereinafter also referred to as "PPVE units") can be cited "F Polymer 2"). The F polymer 2 containing more than 2 mol% of PPVE units is easy to generate micro crystals, and is easy to be mixed with fillers to a high degree to form dense moldings. The F polymer 2 includes TFE units and PPVE units, and preferably contains 96-98 mol% of TFE units and 2-4 mol% of PPVE units.

As a preferable aspect of the F polymer, a polymer containing a TFE unit and a unit based on perfluoromethyl vinyl ether (hereinafter also referred to as "PMVE unit") (hereinafter also referred to as "F polymer 3") ). Since F polymer 3 contains PMVE units with short side chains, it is easy to generate tiny crystals, and it is easy to mix fillers to a high degree to form compact molded products. The F polymer 3 preferably contains 10-20 mol% of PMVE units. The F polymer 3 includes TFE units and PMVE units, and preferably contains 80-90 mol% of TFE units and 10-20 mol% of PMVE units.

The MO filler of the present invention is a filler containing more than 50% by mass of metal oxide. The metal oxide contained in the MO filler may be one type or two or more types. The content of the metal oxide in the MO filler is preferably 90% by mass or more, more preferably 95% by mass or more. The content of the metal oxide is preferably 100% by mass or less.

From the viewpoint of improving the thermal conductivity and scratch resistance of the molded article, the metal oxide is preferably at least one selected from the group consisting of the following metal oxides: aluminum oxide, lead oxide, iron oxide, and tin oxide , Calcium oxide, magnesium oxide, titanium oxide, zinc oxide, antimony pentoxide, zirconium oxide, lanthanum oxide, neodymium oxide, cerium oxide and niobium oxide. From the viewpoint of thermal conductivity, aluminum oxide or magnesium oxide is more preferred From the viewpoint of low dielectric loss tangent, magnesium oxide is more preferable.

Examples of magnesium oxide include hard-burned magnesium oxides such as fused magnesium oxide and magnesium oxide sintered products, and specific examples thereof include magnesia RF-10C and magnesia RF-50 (manufactured by UBE MATERIALS Co., Ltd.).

The MO filler preferably further contains silicon oxide (silicon dioxide). In this case, the interaction between the components in the dispersion is strong and the dispersibility is easily improved. The content of silicon oxide contained in the MO filler is preferably 0% by mass or more and 50% by mass or less, and more preferably 0% by mass or more and 20% by mass or less. The silica contained in the MO filler is preferably included on the surface of the filler, and is preferably included in a manner of covering the surface of the filler. In this case, not only the dispersibility of the dispersion liquid is improved, but also the balance of the physical properties derived from the metal oxide of the formed article formed therefrom is improved. In addition, it is easy to improve the water resistance of the molded article.

The silica contained in the MO filler is preferably a cured product derived from a silica filler, a silane coupling agent, reactive silicone, or silicone. The silane coupling agent is preferably 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane , 3-methacryloxypropyl triethoxysilane or 3-isocyanatopropyl triethoxysilane. The siloxane is preferably polysiloxane or oligomer-like siloxane, more preferably oligomer-like siloxane. The oligomer-like silicone is preferably an oligomer-like silicone having a reactive group in the side chain. Examples of the reactive group include a vinyl group, an amino group, an epoxy group, a methacryloxy group, an acryloxy group, and a mercapto group. The average degree of polymerization of the oligomeric silicone is preferably 2-20.

The oligomeric silicone is preferably a homopolymer of a silane coupling agent with a reactive group, or a copolymer of a silane coupling agent with a reactive group and a silane coupling agent without a reactive group, more preferably ethylene Homopolymer of methoxysilane, or copolymer of trimethoxysilane with amine group and trimethoxysilane with alkyl group. Specific examples of oligomeric silicones include the oligomeric silicones described in Japanese Patent Laid-Open No. 5-194544 and Japanese Patent Laid-Open No. 2000-178449. More specifically, Examples include Dynasylan 6490 or Dynasylan 1146 (manufactured by Evonik Degussa Japan Co., Ltd.). As a specific example of the MO filler containing silicon oxide, a filler containing magnesium oxide, calcium oxide, and silica in order of 94.0-99.7 mass%, 0.1-1.5 mass%, and 0.1-3.0 mass% can be cited. The MO filler is preferably obtained by mixing each component and firing it.

The MO filler may be particulate or fibrous. If a particulate filler is used, a part of the filler particles will be exposed on the surface of the molded product, and it is easier to improve the abrasion resistance and scratch resistance of the surface of the molded product. On the other hand, if a fibrous filler is used, since the surface flatness of the molded article is improved, the sliding properties of the surface become better, and therefore it is still easier to improve the scratch resistance.

The average particle diameter (D50) of the particulate filler is preferably 0.02 to 200 μm. In addition, the average fiber length of the fibrous filler is preferably 0.05 to 300 μm. The average fiber diameter of the fibrous filler is preferably 0.01-15 μm. The average particle diameter of the particulate filler is preferably equal to or greater than the average particle diameter of the powdered filler. In addition, the average fiber length of the fibrous filler is preferably more than the average particle diameter of the powdered filler. In this case, not only the precipitation of the filler in the dispersion is suppressed, but also the physical properties (heat transfer, scratch resistance, electrical properties, etc.) of the molded article are more easily improved.

As a preferable aspect of the MO filler, particles of alumina or magnesia, or fibers of alumina or magnesia are preferred. If the particles are used, it is easier to improve the abrasion resistance and scratch resistance of the surface of the molded article. On the other hand, if the fiber is used, it is easier to improve the scratch resistance of the surface of the molded article. Moreover, as a preferable aspect of the MO filler, magnesium oxide particles surface-treated with an oligomer-like siloxane having a reactive group, and magnesium oxide particles containing silicon oxide and calcium oxide can also be cited. This kind of filler is easy to improve the low dielectric loss tangent and low transmission loss of the molded article.

The MO filler may further include nitrides (boron nitride, silicon nitride, aluminum nitride, etc.). The content of nitride in this preferred aspect is preferably 5 to 75% by mass. In addition, as an aspect of the MO filler containing nitride, an aspect having a core-shell structure with a metal oxide as a core and a nitride as a shell can be cited. When forming the core-shell type MO filler, a sintering aid can be further used.

The SO filler of the present invention is a filler containing silica which is different from the MO filler. The content of silica in the SO filler exceeds 50% by mass, preferably 90% by mass or more. The content of silicon oxide is preferably 100% by mass or less. The SO filler is preferably silica filler, talc filler or talc filler. In this case, the interaction between the components in the dispersion is enhanced, which is easy to improve the dispersibility. In addition, it is easy to improve the balance of the physical properties of the molded product derived from silicon oxide, especially the electrical characteristics (low dielectric loss tangent, etc.).

The SO filler is preferably surface-treated at least a part of its surface. The shape of the SO filler can be any of granular, needle-like (fibrous), and plate-like. Specific shapes of SO fillers include: spherical, scaly, layered, leaf-shaped, almond-shaped, columnar, coronal, equiaxed, leaf-shaped, mica-shaped, massive, flat, and wedge-shaped. , Rose flower-shaped, net-shaped, angular columnar. The shape of the SO filler is preferably spherical or scaly. In this case, the interaction between the components in the dispersion is increased to increase the dispersibility, and to improve the balance of the physical properties of the formed product derived from the components.

The average particle size of the SO filler is preferably 0.1-10 μm. As a specific example of the filler containing spherical silica, a filler containing substantially spherical silica can be cited. Furthermore, the so-called substantially spherical filler means that 95% of spherical particles with the ratio of the short diameter to the long diameter of 0.7 or more when observed by Scanning Electron Microscope (SEM) The above inorganic fillers.

The filler containing spherical silica may have a single-layer structure or a multilayer structure. In addition, the spherical SO filler may also be sintered ceramics. As a specific example of the scaly SO filler, a filler having an average major diameter (average value of the diameter in the longitudinal direction) of 1 μm or more and 10 μm or less, and an average minor diameter of 0.01 μm or more and 1 μm or less can be cited. The flaky SO filler may have a single-layer structure or a multilayer structure. In addition, the scaly SO filler may also be sintered ceramics.

The structure of the SO filler is preferably hollow. In this case, the linear expansion and electrical properties (especially low dielectric property and low dielectric loss tangent) of the molded article obtained from it are easy to balance. The hollow ratio of the hollow SO filler (the average of the volume ratio of the voids of each filler particle) is preferably 50 to 80%. In addition, the compressive strength of the hollow SO filler is preferably 20 MPa or more.

Specific examples of SO fillers include spherical silica fillers ("Admafine" series manufactured by Admatechs, "SFP" series manufactured by Denka Company, etc.), hollow silica fillers (made by Pacific Cement Company, etc.) E-SPHERES" series, "SiliNax" series manufactured by Nippon Steel Mining Company, "Ecco sphere" series manufactured by Emerson & Cuming, etc.), talc filler ("SG" series manufactured by Japanese Talc Company, etc.), lump talc filler (The "BST" series manufactured by Japan Talc Company, etc.). One type of SO filler may be used alone, or two or more types may be used. SO fillers can also be used in combination with hollow fillers and non-hollow fillers. In this case, the dispersion stability of the dispersion is easy to be excellent, and the low linear expansion and low dielectric loss tangent of the molded product are easy to be excellent.

The polar liquid dispersion medium of the present invention is a liquid component that disperses F powder, MO filler and SO filler, and is a compound that is liquid at 25°C. The liquid dispersion medium may be protic or aprotic. In addition, the liquid dispersion medium may be an aqueous solvent or a non-aqueous solvent. A liquid dispersion medium may be used individually by 1 type, and may use 2 or more types together. The liquid dispersion medium is preferably water, amide, alcohol, arylene, ester, ketone or glycol ether, more preferably water, ketone or amide, and still more preferably ketone or amide.

Specific examples of the liquid dispersion medium include: water, methanol, ethanol, isopropanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2 -Pyrolidone, dimethyl sulfide, diethyl ether, dioxane, ethyl lactate, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isopropyl ketone, cyclopentanone, cyclohexanone , Ethylene glycol monoisopropyl ether, cellosolve (methyl cellosolve, ethyl cellosolve, etc.). The liquid dispersion medium is particularly preferably water, methyl ethyl ketone, cyclohexanone or N-methyl-2-pyrrolidone.

From the viewpoint of further improving the dispersibility of F powder, MO filler, and SO filler, the dispersion of the present invention preferably further contains a nonionic surfactant (dispersant). In addition, it is believed that the nonionic surfactant also plays a role in increasing the viscosity of the dispersion, and also functions as an anti-precipitation agent to prevent the precipitation of the F powder and the filler of the two in the dispersion. Examples of the nonionic surfactant include: non-polymeric compounds containing hydroxyl and polyoxyalkylene groups (1), compounds containing hydrolyzable silyl groups (2), non-polymers containing fluorine-containing groups and hydroxyl groups Shape compound (3), polyhydroxy compound (4), acetal group or hemiacetal group-containing polymer (5), and hydroxyl group or polyoxyalkylene-containing polymer (6).

Specific examples of the compound (1) include oxyalkylene glycol and oxyalkylene glycol monoether. More specifically, the general formula: R ¹ O(CH ₂ CH ₂ O) _m1 H The compound represented (where R ¹ is a hydrogen atom or an alkyl group with 10-15 carbon atoms, and m1 represents the average number of added moles and is an integer of 1-15). As a specific example of the compound (2), a silicon compound represented by the ^{general formula: (R 21} ) _m21 -Si-(OR ²² ) _4-m21 ^{(where R 21} is an alkyl group with 1 to 12 carbon atoms, R ²² is an alkyl group having 1 to 4 carbon atoms, and m21 is an integer of 1 to 3). As a specific example of the compound (3), a compound represented by the general formula: R ³³ -O-(CH ₂ CH ₂ O) _m31 (CH ₂ CH(CH ₃ )O) _m32 H (wherein R ³¹ is For the polyfluoroalkyl group having 1 to 12 carbon atoms, m31 is an integer of 1 to 12, b is an integer of 1 to 20, and m32 is an integer of 0 to 12).

Specific examples of the polyhydroxy compound (4) include: polyvinyl alcohol, polyethylene glycol, polyethylene oxide, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, starch , Agarose, lactose. Specific examples of the polymer (5) include a ternary polymer containing a unit based on ethylene butyraldehyde, a unit based on vinyl acetate, and a unit based on vinyl alcohol. Furthermore, the ratio of each unit is not particularly limited, and it is set in consideration of the ease of interaction with the F polymer, metal oxide, and solvent. Specific examples of the polymer (6) include fluorine-based surfactants, silicone-based surfactants, and acetylene-based surfactants.

The nonionic surfactant is preferably a polymer having an alcoholic hydroxyl group or a polyoxyalkylene group, a perfluoroalkyl group, a perfluoroalkyl group or a perfluoroalkenyl group having an etheric oxygen atom in the side chain, respectively Nonionic surfactant (hereinafter also referred to as "polymer dispersant F"). In this case, the affinity of the nonionic surfactant for each component is balanced. In addition to the dispersibility of the powder and filler in the dispersion, the film-forming properties are also easily improved.

It is more preferable that the polymer dispersant F has a fluorine content of 10 to 50% by mass and a hydroxyl value of 10 to 35 mg KOH/g. As the polymer dispersant F, a polymer containing a fluorine (meth)acrylate-based unit and an oxyalkylene glycol mono(meth)acrylate-based unit can be cited. Furthermore, this polymer is a polymer other than F polymer. As a specific example of the former (meth)acrylate, CH ₂ =C(CH ₃ )C(O)OCH ₂ CH ₂ (CF ₂ ) ₆ F, CH ₂ =CHC(O)OCH ₂ CH ₂ (CF ₂ ) ₆ F、CH ₂ =C(CH ₃ )C(O)OCH ₂ CH ₂ (CF ₂ ) ₄ F、CH ₂ =CClC(O)OCH ₂ CH ₂ (CF ₂ ) ₄ F、CH ₂ =C(CH ₃ )C(O)OCH ₂ CH ₂ CH ₂ CH ₂ OCF(CF ₃ )C(=C(CF ₃ ) ₂ )(CF(CF ₃ ) ₂ ), CH ₂ =CH ₃ C(O )OCH ₂ CH ₂ CH ₂ CH ₂ OCF(CF ₃ )C(=C(CF ₃ ) ₂ )(CF(CF ₃ ) ₂ ).

Specific examples of the latter (meth)acrylate include: CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₄ OH, CH ₂ =C(CH ₃ )C(O)( OCH ₂ CH ₂ ) ₉ OH、CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₂₃ OH、CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₆₆ OH、 CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₉₀ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₁₂₀ OH, CH ₂ =CHC(O)( OCH ₂ CH ₂ ) ₄ OH、CH ₂ =CHC(O)(OCH ₂ CH ₂ ) ₈ OH、CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH(CH ₃ )) ₄ OH、CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH(CH ₃ )) ₈ OH、CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH(CH ₃ )) ₉ OH、CH ₂ =C (CH ₃ )C(O)(OCH ₂ CH(CH ₃ )) ₁₃ OH、CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₄ -(OCH ₂ CH(CH ₃ )) ₃ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₁₀ -(OCH ₂ CH ₂ CH ₂ CH ₂ ) ₅ OH.

From the viewpoint of improving the coating properties of the dispersion (inhibiting the fall of F powder when the polymer layer is formed from the dispersion, etc.) and the smoothness of the molded product, the dispersion of the present invention preferably further contains a binder. As the binder, maleimide resin, polyimide resin, polyimide resin, polyimide resin, (meth)acrylic resin, polyurethane resin, glyoxal resin, or phenol The resin is more preferably maleimide resin, polyimide resin, or polyimide resin. Furthermore, these resins are preferably thermoplastic resins, and particularly preferably those whose glass transition temperature is below the melting temperature of the F polymer. In addition, these resins are preferably binder resins dissolved in a liquid dispersion medium.

The content of the F polymer in the dispersion of the present invention is preferably 5% by mass or more, preferably 10-60% by mass, more preferably 20-40% by mass. In this case, it is easy to form a molded product with excellent physical properties (especially electrical properties). The content of the MO filler in the dispersion of the present invention is 5% by mass or more, preferably 8% by mass or more, and more preferably 10% by mass or more. Furthermore, the upper limit thereof is generally preferably 50% by mass, and more preferably 40% by mass. The content of the SO filler in the dispersion of the present invention is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more. Furthermore, the upper limit is preferably 40% by mass, more preferably 30% by mass. The ratio of the content of the SO filler to the content of the MO filler in the dispersion of the present invention is less than 1, preferably 0.8 or less. The ratio is preferably 0.2 or more, more preferably 0.5 or more.

The content of the liquid dispersion medium in the dispersion of the present invention is preferably 15 to 55% by mass, more preferably 25 to 50% by mass. In this case, the coating properties of the dispersion are excellent, and the film-forming properties are also easily improved. Moreover, when the dispersion liquid of the present invention contains a nonionic surfactant, the content is preferably 0.1-10% by mass, more preferably 0.5-5% by mass. In this case, the dispersibility of the powder and filler in the dispersion is further improved, and the physical properties (thermal conductivity, scratch resistance, etc.) of the molded article are easily further improved. Moreover, when the dispersion liquid of the present invention contains a binder, its content is preferably 0.1-30% by mass, more preferably 1-10% by mass. The ratio of the content of the binder resin to the content of the F polymer is preferably 1.0 or less, and more preferably 0.01 to 0.5.

The sum of the content of the F polymer, the content of the MO filler, and the content of the SO filler contained in the dispersion of the present invention is preferably 20% by mass or more, more preferably 30% by mass or more, and still more preferably 40% by mass or more. As described above, since the F polymer interacts with the fillers of both in the dispersion liquid to a high degree, even when the above sum is high, the dispersion liquid of the present invention has excellent dispersibility and coatability. The above sum is preferably 80% by mass or less. In addition, the mass ratio of the content of the MO filler relative to the content of the F polymer is preferably 0.1 or more, more preferably 0.3 or more. The quality is preferably 2 or less, and more preferably 1 or less. The quality of the content of the SO filler relative to the content of the F polymer is preferably 0.1 or more, more preferably 0.2 or more. The quality is preferably 2 or less, and more preferably 1 or less. As described above, since the F polymer, the MO filler, and the SO filler interact highly in the dispersion, even when the quality is relatively high, the dispersion of the present invention has excellent dispersibility and coatability. As a result, it is possible to easily form a molded article containing both fillers uniformly and at a high concentration from the dispersion of the present invention. The above-mentioned quality is preferably 2 or less, and more preferably 1 or less.

The dispersion of the present invention may further contain other resins. Examples of the above-mentioned other resins include epoxy resins, liquid crystal polyester resins, polyolefin resins, cyanate ester resins, vinyl ester resins, urea resins, diallyl phthalate resins, melanin resins, and guanamine resins. , Melamine-urea co-condensation resin, styrene resin, polycarbonate resin, polyarylate resin, polyimide, polyarylene, aromatic polyamide resin, aromatic polyether amide, polyphenylene sulfide, polyarylene Ether ketone, polyphenylene ether. These other resins may be dissolved in the dispersion liquid, or may not be dissolved in the dispersion liquid. In addition, other resins may be thermosetting or thermoplastic. Also, other resins can be modified. In addition, the dispersion of the present invention may further include: a thixotropy imparting agent, a defoaming agent, a silane coupling agent, a dehydrating agent, a plasticizer, a weathering agent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, and a whitening agent. Agent, coloring agent, conductive agent, release agent, surface treatment agent, viscosity regulator, flame retardant.

The viscosity of the dispersion of the present invention at 25°C is preferably 10000 mPa·s or less, more preferably 50 to 5000 mPa·s, and still more preferably 100 to 1000 mPa·s. In this case, the dispersion is not only excellent in dispersibility, but also excellent in handleability. In addition, the thixotropic ratio of the dispersion of the present invention is preferably 1.0 to 2.5, and more preferably 1.2 to 2.0. In this case, not only the dispersibility of the dispersion liquid is excellent, but the homogeneity of the molded product is also easily improved.

The dispersion of the present invention contains a large amount of F powder, MO filler and silicic acid filler, and has excellent dispersion stability. In addition, the molded product can highly possess the physical properties of the F polymer and the physical properties of the filler. If the dispersion liquid of the present invention is used, a thick molded product with a thermal conductivity of 1 W/mK or more, or a molded product with a dielectric loss tangent of 0.005 or less can be easily obtained.

The manufacturing method of the laminate of the present invention is to apply the dispersion of the present invention to the substrate layer, heat to volatilize the polar liquid dispersion medium, and then heat to sinter the F polymer to obtain a substrate layer containing A method of a laminate of polymer layers of F polymer, MO filler and SO filler (hereinafter also referred to as "this laminate").

As the base layer of the present invention, metal substrates (metal foils such as copper, nickel, aluminum, titanium, alloys of these, etc.), resin films (polyimide, polyarylate, polyarylene, polyarylene, Films of polyamide, polyetheramide, polyphenylene sulfide, polyaryletherketone, polyamideimide, liquid crystal polyester, liquid crystal polyesteramide, etc.), prepreg (fiber-reinforced resin substrate) Predecessor). As the base material layer, a metal substrate and a resin film are preferable.

The metal substrate is preferably a copper foil, more preferably a rolled copper foil with no difference between the front and back sides, or an electrolytic copper foil with a difference between the front and back sides, and more preferably a rolled copper foil. The rolled copper foil has a small surface roughness, so even when the laminate is processed into a printed wiring board, the transmission loss can be reduced. An anti-rust layer (oxide film such as chromate, etc.), a heat-resistant layer, a roughening treatment layer, and a silane coupling agent treatment layer can be provided on the surface of the metal substrate. As the resin film, a polyimide film is preferred. The thickness of the substrate layer is preferably 0.1 to 150 μm. Specifically, if the base material layer is a metal foil, the thickness of the base material layer is preferably 1-30 μm. If the substrate layer is a resin film, the thickness of the substrate layer is preferably 1 to 150 μm, more preferably 10 to 50 μm.

The dispersion liquid may be applied to only one surface of the base material layer, or the dispersion liquid may be applied to both surfaces of the base material layer. In the former case, a laminate having a substrate layer and a polymer layer on one surface of the substrate layer can be obtained. In the latter case, a laminate having a substrate layer and a substrate layer on both surfaces can be obtained. Laminated body of polymer layers. The latter layered body is less likely to warp, so it has excellent processing rationality. The coating of the dispersion liquid can be implemented by the following methods: spray method, roll coating method, spin coating method, gravure coating method, micro gravure coating method, gravure offset method, knife coating method, contact coating method, bar type Coating method, die nozzle coating method, jet Meyer rod method, slit die nozzle coating method and other methods. Furthermore, heating is preferably performed in the temperature range where the F polymer is fired. Heating can be carried out at a fixed temperature or at different temperatures. As a heating method, a method of using an oven, a method of using a ventilated drying oven, and a method of irradiating hot rays such as infrared rays can be cited. The heating can be carried out under either the normal pressure or the reduced pressure.

In addition, the present laminate only needs to have a polymer layer in contact with at least one surface of the base layer. Examples of the layer structure include: base layer/polymer layer, base layer/polymer layer/base layer, polymer layer/base layer/polymer layer, base layer/polymer layer/other Substrate layer/polymer layer/substrate layer. Furthermore, the so-called "base material layer/polymer layer" means that a base material layer and a polymer layer are laminated in this order, and the composition of other layers is also the same. Furthermore, the definition of another substrate layer, including the scope and preferred aspects, is the same as the above-mentioned substrate layer.

In the present laminate, the thickness of the polymer layer is preferably 1-100 μm, more preferably 5-75 μm, and still more preferably 10-50 μm. The peel strength of the polymer layer and the substrate layer of the laminate is also higher. The peel strength is preferably 10 N/cm or more. In addition, the thermal conductivity of the polymer layer is preferably 1 W/m·K or more, more preferably 2 W/m·K or more, and still more preferably 3 W/m·K or more. The upper limit of the thermal conductivity of the polymer layer is 100 W/m·K.

Since this laminate has a polymer layer containing F powder, MO filler and SO filler, it has excellent physical properties such as heat resistance, electrical properties, thermal conductivity (heat dissipation), and scratch resistance. It is used as a flexible printed wiring board and rigid printed wiring. Electronic substrate materials such as substrates or heat-dissipating substrates, especially heat-dissipating substrates used in automobiles, are useful. For example, if the base layer of the laminate is a metal foil, the metal foil can be etched and processed into a metal conductor wiring (transmission circuit) of a specific pattern to produce a printed wiring board. The printed wiring board has a metal conductor wiring and a polymer layer in this order. Examples of the structure include metal conductor wiring/polymer layer, and metal conductor wiring/polymer layer/metal conductor wiring. In addition, a plurality of printed wiring boards of the above-mentioned configuration may be multilayered. Moreover, the bonding sheet, the interlayer insulating film, the solder resist, and the cover layer film in the printed wiring board can also be formed by the dispersion liquid of this invention.

As a preferable aspect of the printed wiring board formed by this laminated body, the aspect which has a transmission circuit, a polymer layer, and an aluminum board|substrate formed by the metal foil or processing in this order can also be mentioned. Examples of the configuration of the above aspect include: metal foil/polymer layer/aluminum substrate, transmission circuit formed by processing metal foil/polymer layer/aluminum substrate, metal foil/polymer layer/aluminum substrate/polymer layer/ Metal foil, the above-mentioned transmission circuit/polymer layer/aluminum substrate/polymer layer/the above-mentioned transmission circuit, the above-mentioned transmission circuit/polymer layer/aluminum substrate/polymer layer/metal foil.

As a preferable aspect of the printed wiring board formed by this laminated body, the aspect which has a transmission circuit, a polymer layer, and a resin film layer formed by the metal foil or processing in this order can also be mentioned. The configuration of the above aspect includes: metal foil/polymer layer/resin film layer, transmission circuit formed by processing metal foil/polymer layer/resin film layer, metal foil/polymer layer/resin film layer/polymer Material layer/metal foil, the above-mentioned transmission circuit/polymer layer/resin film layer/polymer layer/the above-mentioned transmission circuit, the above-mentioned transmission circuit/polymer layer/resin film layer/polymer layer/metal foil.

The polymer layer of the present invention contains F polymer with excellent adhesiveness and heat resistance and SO filler with excellent electrical properties with high uniformity, and contains a large amount of MO filler, so it is easy to interact with any substrate (metal foil or transmission circuit and Aluminum substrate) is firmly bonded. This type of laminate or printed wiring board can also be called an aluminum-based laminate or aluminum-based printed wiring board with excellent heat resistance and thermal conductivity. It can be suitably used in a high-temperature environment and requires high heat dissipation. The purpose of the power module (LED lighting, etc.).

From the viewpoint of further improving adhesiveness, the polymer layer of these aspects can be surface-treated. As a method of surface treatment, methods using corona treatment, plasma treatment, electron beam treatment, etc. can be cited. Furthermore, from the viewpoint of further improving adhesiveness, an adhesive layer (a layer formed by a silane coupling agent, etc.) may be further formed on the surface of the polymer layer. The thickness of the polymer layer is preferably 1 to 200 μm, more preferably 3 to 20 μm. As the material of the aluminum substrate, aluminum and aluminum alloy can be cited. From the viewpoint of annealing resistance, the aluminum alloy is preferably an alloy of aluminum and manganese, magnesium, or chromium. The surface of the aluminum substrate can be roughened or coated. The thickness of the aluminum substrate is preferably 0.5-3 mm. If the thickness of the polymer layer and the aluminum substrate are in the above ranges, it is easy to form a circuit substrate with higher heat dissipation.

The molded article of the present invention contains F polymer, MO filler, and SO filler. The content of the polymer contained in the molded article is 50% by mass or more, and the sum of the contents of the MO filler and the SO filler contained in the molded article is 10% by mass or more. The definitions of F polymer, MO filler and SO filler in the molded article of the present invention, including their preferred aspects and ranges, are the same as the description of the manufacturing method of the dispersion and laminate of the present invention. The molded article of the present invention is preferably a single-layer film composed of a polymer layer.

It is believed that in the molding of the present invention, the MO filler and SO filler are uniformly and firmly maintained in the matrix of the F polymer, and the physical properties (thermal conductivity, scratch resistance, electrical properties, etc.) based on metal oxides and silica are good. To play. In addition, since the F polymer has an oxygen-containing polar group, the molded article exhibits high adhesiveness on its surface. Therefore, the molded article of the present invention can be used as a heat dissipation film, a protective film, etc., as long as it is bonded to a circuit board on which a semiconductor chip is mounted so as to cover the semiconductor chip. In addition, the molded article of the present invention can also be suitably used as an adhesive layer between electronic parts and heat sinks accompanied by heat generation.

The content of the F polymer contained in the molded article of the present invention is preferably 50% by mass or more, more preferably 60 to 80% by mass. In this case, it is easy to form a polymer layer with excellent physical properties (especially electrical properties). The sum of the content of the MO filler and the content of the SO filler contained in the molded article of the present invention is 10% by mass or more, preferably 20% by mass or more. Furthermore, the upper limit of the sum of the contents of the MO filler and the SO filler contained in the molded article of the present invention is 50% by mass. The polymer layer containing a large amount of metal oxide filler can further better exhibit the physical properties (thermal conductivity, scratch resistance, etc.) based on the metal oxide. In addition, the polymer layer containing a large amount of SO filler can further better exhibit the physical properties (electrical properties, low linear expansion, etc.) based on silica.

The content of the MO filler contained in the molded article of the present invention is preferably 5% by mass or more, more preferably 20% by mass or more. In addition, the upper limit is usually 45% by mass. The content of the SO filler contained in the molded product is preferably 5% by mass or more, more preferably 20% by mass or more. In addition, the upper limit is usually 45% by mass.

The thickness of the molded article of the present invention is preferably 1 to 1000 μm, more preferably 5 to 100 μm, and still more preferably 10 to 50 μm. As long as it is a molded product of this thickness, it can fully ensure mechanical strength and exhibit high flexibility (softness). Therefore, it is useful as a heat dissipation film, a protective film, and the like.

The thermal conductivity of the molded article of the present invention is preferably 1 W/mK or more, more preferably 2 W/m·K or more, and still more preferably 3 W/m·K or more. The upper limit of the thermal conductivity of the molded product is 100 W/m·K. Since the molded product has excellent thermal conductivity, it is useful as a heat dissipation film. The dielectric loss tangent of the molded article is preferably 0.005 or less, more preferably 0.003 or less. The lower limit of the dielectric loss tangent of the molded article is zero. Since the molded article of the present invention is excellent in low dielectric loss tangent, it is useful as a material for a substrate for electronic equipment such as a printed circuit board.

In addition, in order to improve electrical insulation or mechanical strength, a fibrous base material may be embedded in the molded product. As the fiber substrate, heat-resistant heat-resistant woven fabrics are preferred, glass fiber woven fabrics, carbon fiber woven fabrics, aromatic polyamide fiber woven fabrics or metal fiber woven fabrics are more preferred, and glass fiber woven fabrics are more preferred. Or carbon fiber woven cloth. In particular, from the viewpoint of improving electrical insulation, it is preferable to use a plain woven glass fiber woven fabric containing E glass yarn for electrical insulation specified in JIS R 3410:2006 as the fiber substrate. At this time, if the fiber substrate is treated with a silane coupling agent, the adhesion with the F polymer will be further improved.

The molded product of the present invention can also be obtained by applying the dispersion of the present invention to the surface of the substrate layer and heating to form a polymer layer containing F polymer, MO filler and SO filler, and then removing the base.材层。 The material layer. In other words, it can also be said that the molded product of the present invention is obtained by removing the substrate from the laminate of the present invention. Here, the molded article in which the fiber base material is embedded can also be produced by impregnating the fiber base material with the dispersion of the present invention, and then heating the fiber base material to sinter the F powder.

When manufacturing this molded article, the removal of the base material layer can use either wet etching or dry etching. When the base material layer is a metal foil, it is preferable that the metal foil is removed by wet etching. In this case, it is preferable to perform wet etching using an acid solution. If the F polymer has an oxygen-containing polar group, it is activated by an acid solution, so it is easy to further improve the adhesion of the surface (contact surface) of the molded article after the metal foil is removed. Here, as an example of activation of the oxygen-containing polar group, the conversion of an acid anhydride group into a 1,2-dicarboxylic acid group can be cited. Furthermore, as the acid solution, an inorganic acid aqueous solution such as hydrochloric acid, dilute nitric acid, or hydrofluoric acid can be used. In addition, in the case of using a roughened metal foil, the surface (contact surface) of the film is transferred with minute irregularities. Therefore, when other substrates are adhered to the surface of the molded article, the adhesion with other substrates becomes better.

As described above, if wet etching is used to remove the metal foil, it is possible to prevent damage to the minute concave and convex shapes transferred to the surface of the molded article, and to remove the metal foil reliably. If the molded article of the present invention and the base layer are thermocompression bonded, a laminate having the base layer and the molded article can be obtained. The definition of the substrate layer, including its preferred aspect and range, is the same as the description of the laminate of the present invention.

As mentioned above, although the manufacturing method of the dispersion liquid of this invention, a laminated body, and a molded object were demonstrated, this invention is not limited to the structure of the said embodiment. For example, the dispersion and the molded article of the present invention may have other arbitrary configurations added to the configurations of the above-mentioned embodiments, respectively, or may be replaced with arbitrary configurations that produce the same effect. In addition, in the method of manufacturing a laminate of the present invention, other arbitrary steps may be added to the configuration of the above-mentioned embodiment, respectively, and may be replaced with arbitrary steps that produce the same effect. [Example]

Hereinafter, the present invention will be described in detail with examples, but the present invention is not limited by these. 1. Preparation of each ingredient [powder] Powder 1: Powder (D50) which contains TFE units, NAH units and PPVE units in order of 98.0 mol%, 0.1 mol%, and 1.9 mol%, and a copolymer with oxygen-containing polar groups (melting temperature: 300°C) : 1.8 μm, D90: 5.2 μm) Powder 2: A powder containing a copolymer (melting temperature 305°C) containing 97.5 mol%, 2.5 mol% of TFE units and PPVE units in sequence without oxygen-containing polar groups (D50: 18.8 μm, D90: 52.3 μm) ) Powder 3: Powder containing a copolymer (melting temperature of 305°C) containing 98.7 mol%, 1.3 mol% of TFE units and PPVE units in sequence without oxygen-containing polar groups (D50: 0.3 μm, D90: 0.9 μm) ) Powder 4: powder containing non-melting PTFE (D50: 3.2 μm)

[Filler] MO1: Granular magnesium oxide filler (D50: 10 μm; "magnesia RF-10C" manufactured by UBE MATERIALS Co., Ltd.; content of magnesium oxide: more than 50% by mass) MO2: Alumina filler (D50: 3 μm ; "AA-3" manufactured by Sumitomo Chemical Company; alumina content: more than 50% by mass) SO1: spherical and hollow silica filler (D50: 4 μm; "E-SPHERES" manufactured by Pacific Cement Corporation ; Silica content: more than 50% by mass) SO2: scaly talc filler (D50: 4.8 μm, average long diameter: 5.7 μm, average short diameter: 0.3 μm, aspect ratio: 20, "BST" manufactured by Japan Talc "; Silicon oxide content: more than 50% by mass) [Binder] Varnish 1: Thermoplastic aromatic polyimide (PI1) dissolved in NMP varnish [Non-ionic surfactant] Surfactant 1: CH2=C(CH ₃ )C(O)OCH ₂ CH ₂ (CF ₂ ) ₆ F and CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₂₃ OH copolymer [liquid dispersion medium ] NMP: N-methyl-2-pyrrolidone

2. Preparation of dispersion (example 1) First, the powder 1, varnish 1, surfactant 1, and NMP are put into the crucible, and zirconia balls are put into it. After that, the crucible was rotated at 150 rpm for 1 hour, thereby preparing the composition. Put filler MO1, filler SO1, surfactant 1, and NMP into another crucible, and put zirconia balls. After that, the crucible was rotated at 150 rpm for 1 hour, thereby preparing the composition. Put the combination of the two into another crucible, and put the zirconia balls. After that, the crucible was rotated at 150 rpm for 1 hour to obtain powder 1 (20 parts by mass), filler MO1 (10 parts by mass), filler SO1 (5 parts by mass), PI1 (1 part by mass), and surfactant 1 ( 4 parts by mass) and NMP (60 parts by mass) of dispersion liquid 1.

(Examples 2～8) Except that the types and amounts of powder, filler, varnish, surfactant, and liquid dispersion medium were changed as shown in the following table, dispersions 2 to 8 were obtained in the same manner as in Example 1.

[Table 1] Dispersion number powder filler Adhesive resin Surfactant Liquid dispersion medium 1 Powder 1 (20) MO1(10) SO1(5) PI1(1) Surfactant 1 (4) NMP(60) 2 Powder 2 (20) MO1(10) SO1(5) PI1(1) Surfactant 1 (4) NMP(60) 3 Powder 3 (20) MO1(10) SO1(5) PI1(1) Surfactant 1 (4) NMP(60) 4 Powder 4 (20) MO1(10) SO1(5) PI1(1) Surfactant 1 (4) NMP(60) 5 Powder 1 (20) MO1(10) PI1(1) Surfactant 1 (4) NMP(65) 6 Powder 1 (20) SO1(5) SO2(10) PI1(1) Surfactant 1 (4) NMP(60) 7 Powder 1 (20) MO2(10) SO1(5) PI1(1) Surfactant 1 (4) NMP(60) 8 Powder 1 (15) SO1(7) MO1(13) PI1(1) Surfactant 1 (4) NMP(60) ※The value in each bracket in the column of powder, filler, polyimide, surfactant and liquid dispersion medium is the content in the dispersion (unit: mass%).

3. Evaluation 3-1. Evaluation of the dispersion 3-1-1. Evaluation of the dispersion stability After storing each dispersion in a container at 25°C, visually confirm its dispersibility, and determine the dispersion stability according to the following criteria to evaluate. [Evaluation Criteria] ◯: No agglutinate was recognized. △: Agglomerates were also observed to be deposited on the bottom of the container. If shearing is applied and then stirring is applied, it will redisperse evenly. ×: Agglomerates were also observed to be deposited on the bottom of the container. It is difficult to redisperse even if shearing and stirring are applied. 3-1-2. Measurement of viscosity Use a type B viscometer to measure the viscosity of each dispersion at room temperature (25°C) at a rotation speed of 30 rpm. Repeat the measurement of each viscosity three times, and set the average value of the three measurements as the viscosity. 3-1-3. Evaluation of thixotropy A type B viscometer was used to measure the viscosity of each dispersion under the condition of 30 rpm at room temperature (25°C), and set it as the viscosity η ₁ . Similarly, the viscosity was measured under the condition of a rotation speed of 60 rpm and set as the viscosity η ₂ . Divide η ₂ by η _{1 to} calculate the thixotropic ratio. Repeat the viscosity measurement of each for 3 times, and take the average of the 3 measurements.

3-2. Evaluation of multilayer body 3-2-1. Evaluation of Adherence First, the dispersion liquid 1 was applied on the surface of a copper foil with a thickness of 18 μm in a roll-to-roll manner by a reverse gravure coating method to form a liquid coating. Then, the copper foil formed with the liquid coating film was put in a drying oven at 120°C for 5 minutes, and dried by heating. After that, in a far-infrared oven under a nitrogen atmosphere, the dry film was heated at 340°C for 3 minutes. Thereby, the laminated body 1 with the polymer layer (thickness 10 μm) formed on the surface of the copper foil was manufactured.

Except changing the dispersion liquid 1 to be as shown in the dispersion liquids 2 to 8, the layered bodies 2 to 8 were obtained in the same manner as the layered body 1. At this time, the dry coating formed by the dispersion liquid 8 is more likely to fall off than the liquid coating formed by the dispersion liquid 1. Cut out rectangular test pieces (length 100 mm, width 10 mm) from the resulting laminates 1 to 3 and 5 to 8. Then, at a position 50 mm away from one end in the length direction of the test piece, the copper foil and the polymer layer were peeled off from one end in the length direction at 90° with respect to the test piece at a stretching speed of 50 mm/min. Then, the maximum load applied at this time was measured, and the peel strength (N/cm) was evaluated based on the following criteria. Furthermore, the laminated body 4 was not evaluated because it did not have a uniform polymer layer. [Assessment criteria] ○: 10 N/cm or more △: 5 N/cm or more and less than 10 N/cm ×: less than 5 N/cm

3-2-2. Evaluation of transmission loss A transmission line is formed in each of the laminates 1 to 3 and 5 to 8 to produce a printed circuit board. The formation of the transmission line uses a microstrip line. A vector network analyzer ("E8361A" manufactured by Keysight Technologie) was used to process the 28 GHz signal in the printed circuit board, and the Universal Test Fixture was used as a probe to measure the S21 parameter representing the transmission loss. At this time, the characteristic impedance of the line is set to 50 Ω, and the length of the transmission line of the printed circuit board is set to 50 mm to measure the transmission loss.

As a measure of transmission loss, one of the circuit network parameters used to express the characteristics of high-frequency electronic circuits or high-frequency electronic parts, namely "S21-parameter", is set as the transmission loss value. The closer the value is to 0, the smaller the transmission loss. [Assessment criteria] ○: -1.0 dB or more and less than 0 dB △: -1.2 dB or more and less than -1.0 dB ×: less than -1.2 dB

3-3. Evaluation of film 3-3-1. Evaluation of thermal conductivity The copper foil of the laminate 1 was removed by etching with an aqueous ferric chloride solution, and the film 1 was obtained. Except that the layered body 1 was changed to the layered bodies 2, 3, and 5-8, the films 2, 3, and 5-8 were obtained in the same manner as the film 1. Furthermore, the film 8 is more brittle than the film 1.

Then, cut a 10 mm×10 mm square test piece from the center of each film, measure the thermal conductivity (W/m·K) in the in-plane direction, and evaluate it based on the following criteria. [Assessment criteria] ○: 3 W/m·K or more △: 1 W/m·K or more and less than 3 W/m·K ×: Less than 1 W/m·K

3-3-2. Evaluation of Dielectric Loss Tangent Cut a 5 cm×10 cm square test piece from the center of the membranes 1 to 3 and 5 to 8, and use the SPDR (Split Post Dielectric Resonator) method to measure the dielectric loss tangent of the membrane (measurement frequency: 10 GHz). [Assessment criteria] 〇: Less than 0.0010 △: more than 0.0010 and less than 0.0025 ×: more than 0.0025

The above results are collectively shown in Table 2.

[Table 2] Dispersion, laminate or film number 1 2 3 4 5 6 7 8 Dispersions Dispersion stability 〇 〇 △ X △ 〇 〇 〇 Viscosity [mPa・s] 400 500 800 11000 500 600 800 700 Thixotropy ratio 1.5 1.4 1.5 3.0 1.5 1.4 1.6 1.5 Layered body Continuity 〇 〇 △ - 〇 〇 〇 △ Transmission loss 〇 △ △ - X 〇 〇 〇 membrane Thermal conductivity 〇 △ △ - X 〇 〇 〇 Dielectric loss tangent 〇 〇 △ - X △ 〇 〇

Furthermore, the film 7 exposes a part of alumina particles on its surface. In addition, if corona treatment is performed on the surface of the utilization film 3 under a nitrogen atmosphere containing vinyl acetate, it is confirmed that the adhesion is improved.

4. Production of circuit board with aluminum base The dispersion liquid 7 was applied on the surface of a copper foil with a thickness of 12 μm in a roll-to-roll manner by a reverse gravure coating method to form a liquid coating. Then, the copper foil on which the liquid coating film was formed was placed in a drying oven at 120°C for 5 minutes, and dried by heating. After that, in a far-infrared oven under a nitrogen atmosphere, the dry film was heated at 340°C for 3 minutes. By this, a laminate with a polymer layer (thickness: 5 μm) formed on the surface of the copper foil was manufactured. Then, the polymer layer of the laminate was opposed to the aluminum substrate, and thermocompression bonding was performed at 300°C to obtain a laminate in which a copper foil, a polymer layer, and an aluminum substrate were sequentially laminated. Furthermore, the copper foil of the laminate is etched to form a transmission circuit, and an aluminum-based circuit board is obtained. The thermal conductivity of the circuit board is 10 W/m·K or more, and the heat dissipation is excellent.

5. The production of film by spray coating Using the dispersion liquid 7, the surface of an aluminum foil having a thickness of 18 μm was coated by a spray coating method to form a liquid coating film. Then, the aluminum foil formed with the liquid coating film was placed in a drying oven at 120°C for 5 minutes, and dried by heating. After that, the step of coating and drying by spray coating was repeated 4 times. After that, in a far-infrared oven under a nitrogen atmosphere, the dry film was heated at 340°C for 3 minutes. Thereby, a laminate 9 having a polymer layer (thickness: 200 μm) formed on the surface of the aluminum foil was obtained. The aluminum foil of the laminated body 9 is removed by etching, and the film 9 is obtained. The thermal conductivity of the film 9 was measured in the same manner as the method described in the above-mentioned "3-3-1". As a result, the thermal conductivity of the film 9 was evaluated as "o". [Industrial availability]

The dispersion and the molded article of the present invention are used to form antenna parts, printed wiring boards, aircraft parts, automotive parts, power semiconductor parts, heat exchangers, sports equipment, food industry products, saws, gaskets, gaskets, sliding Materials for coatings such as bearings are more useful. The coating layer formed from the dispersion and molded article of the present invention is excellent in chemical resistance, water and oil repellency, heat resistance, electrical properties, etc., especially in adhesiveness, thermal conductivity (heat dissipation), electrical properties, and scratch resistance . The dispersion and the molded article of the present invention are used as substrates for electronic equipment such as radar, network routers, backplanes, wireless infrastructure, etc., which require heat dissipation and high-frequency characteristics, or substrates for various sensors for automobiles, and substrates for engine management sensors. The material of the printed wiring board used is particularly suitable. In addition, the dispersion and the molded article of the present invention are also suitable as materials for forming the outer surface coating layer of heat exchangers (heat sinks, heat transfer tubes, etc.) such as cold and heat equipment that require heat dissipation and antifouling properties. Furthermore, the Japanese patent application No. 2019-095078 filed on May 21, 2019, the Japanese patent application No. 2019-144674 filed on August 6, 2019, and the Japanese patent application filed on November 25, 2019 The specification of No. 2019-212480, the scope of patent application, the drawings, and the entire content of the specification are incorporated herein as the disclosure content of the specification of the present invention.

Claims (15)

A dispersion liquid comprising: tetrafluoroethylene polymer powder with a melting temperature of 200-320°C and thermoplasticity; a metal oxide filler containing more than 50% by mass of metal oxide; a silica filler containing more than 50% by mass of silica; and polar liquid dispersion medium; the content of the above-mentioned metal oxide filler is more than 5% by mass. The dispersion liquid of claim 1, wherein the above-mentioned tetrafluoroethylene-based polymer is at least one polymer selected from the group consisting of: tetrafluoroethylene-based units and oxygen-containing polar groups-based monomers Polymers containing tetrafluoroethylene-based units and perfluoro(propyl vinyl ether)-based units containing 2 mol% or more, and containing tetrafluoroethylene-based units and perfluoroethylene-based ( Methyl vinyl ether) unit polymer. The dispersion of claim 1 or 2, wherein the metal oxide is at least one metal oxide selected from the group consisting of the following metal oxides: aluminum oxide, lead oxide, iron oxide, tin oxide, magnesium oxide, Titanium oxide, zinc oxide, antimony pentoxide, zirconium oxide, lanthanum oxide, neodymium oxide, cerium oxide and niobium oxide. The dispersion liquid according to any one of claims 1 to 3, wherein the above-mentioned metal oxide filler further contains silica. The dispersion liquid of any one of claims 1 to 4, wherein the metal oxide filler is a filler having a particle shape and an average particle size equal to or greater than the average particle size of the powder, or is fibrous and an average fiber length of the powder Fillers above the average particle size. The dispersion liquid of any one of claims 1 to 5, wherein the shape of the silica filler is spherical or scaly. The dispersion liquid of any one of claims 1 to 6, wherein the structure of the silica filler is hollow. The dispersion liquid of any one of claims 1 to 7, wherein the mass ratio of the content of the silica filler to the content of the metal oxide filler is less than 1. Such as the dispersion of any one of claims 1 to 8, its viscosity at 25°C is 10000 mPa·s or less. For example, the dispersion liquid of any one of claims 1 to 9 has a thixotropic ratio of 1.0 to 2.5 at 25°C. A method for manufacturing a laminate, comprising applying a dispersion liquid according to any one of claims 1 to 10 to a substrate layer, heating to volatilize the liquid dispersion medium, and further heating to fire the tetrafluoroethylene-based polymer , Thereby obtaining a laminate having the base material layer and a polymer layer containing the tetrafluoroethylene-based polymer, the metal oxide filler, and the silica filler. A molded article comprising: a tetrafluoroethylene-based polymer with a melting temperature of 200-320°C and thermoplasticity; a metal oxide filler containing more than 50% by mass of metal oxide; a silica filler containing more than 50% Mass% of silicon oxide; the content of the tetrafluoroethylene-based polymer is 50% by mass or more, and the sum of the content of the metal oxide filler and the content of the silica filler is 10% by mass or more. For example, the molded article of claim 12 has a thickness of 1 to 1000 μm. For example, the molded article of claim 12 or 13 has a thermal conductivity of 1 W/mK or more. For the molded article of any one of claims 12 to 14, the dielectric loss tangent is 0.005 or less.