KR20220080069A - plate-shaped composite material - Google Patents

Abstract

To provide an excellent plate-shaped composite material that is harmonized with various characteristics such as relative permittivity and dielectric loss tangent. A plate-shaped composite material comprising a fluororesin and a filler, wherein the filler is a porous inorganic fine particle aggregate formed by agglomeration of inorganic fine particles having an average primary particle diameter of 5 to 200 nm, and a non-porous inorganic particle having an average primary particle diameter of 0.2 to 50 μm including fine particles, wherein the total content of the porous inorganic fine particle aggregate and the non-porous inorganic fine particle is 20 to 90 mass% of the composite material, and the non-porous relative to the total content of the porous inorganic fine particle aggregate and the non-porous inorganic fine particle It is characterized in that the mass ratio of the content of the inorganic fine particles (content of the non-porous inorganic fine particles/(content of the porous inorganic fine particle aggregate + the content of the non-porous inorganic fine particle)) is 0.15 to 0.90, characterized in that the dielectric constant, dielectric It becomes an excellent composite material with harmonization of various properties such as tangent.

Description

plate-shaped composite material

The present invention relates to a plate-shaped composite material suitable for a substrate or the like of a microstrip patch antenna used as a millimeter wave radar or the like.

In recent years, in the automobile industry, research and development on ADAS (Advanced Driving Assistance System) and automatic driving has been actively conducted, and the importance of millimeter wave radar as a sensing technology supporting these is increasing. As a millimeter wave radar for automobiles, from the viewpoint of small size, high performance, and low price, the use of "Microstrip patch antenna", which is a flat antenna in which an antenna element (patch), etc. is printed and wired on a resin substrate, is preferred, In order to improve the performance, the design of the antenna pattern and the examination of the substrate material are in progress.

As a substrate material used for these antennas, polytetrafluoroethylene (PTFE) with a small dielectric loss tangent is one of the most promising ones, and in order to improve mechanical properties, thermal properties and electrical properties, boron nitride, silicon dioxide (silica), It is proposed to mix|blend particulate fillers, such as titanium oxide (titania), and fillers, such as glass fiber and carbon fiber (refer patent documents 1 and 2.).

Patent Document 1: Japanese Patent Laid-Open No. Hei 03-212987 Patent Document 2: Japanese Patent Laid-Open No. Hei 06-119810

The present invention provides an excellent plate-shaped composite material in which various properties such as relative permittivity and dielectric loss tangent are harmonized.

The present inventors, as a result of repeated intensive studies to solve the above problems, include specific porous inorganic fine particle aggregates and specific nonporous inorganic fine particles in a specific range in the fluorine-based resin, so that various characteristics such as dielectric constant and dielectric loss tangent It has been found to be an excellent composite material in harmony.

That is, the present invention is as follows.

<1> A plate-shaped composite material comprising a fluorine-based resin and a filler, wherein the filler is a porous inorganic fine particle aggregate formed by agglomeration of inorganic fine particles having an average primary particle diameter of 5 to 200 nm, and an average primary particle diameter of 0.2 to 50 μm including non-porous inorganic fine particles, wherein the total content of the porous inorganic fine particle aggregate and the non-porous inorganic fine particle is 20 to 90 mass% of the composite material, and the total content of the porous inorganic fine particle aggregate and the non-porous inorganic fine particle is The mass ratio of the content of the non-porous inorganic fine particles to the (content of the non-porous inorganic fine particles/(the content of the porous inorganic fine particle aggregate + the content of the non-porous inorganic fine particle)) is 0.15 to 0.90, characterized in that composite material.

<2> The plate-shaped composite material according to <1>, wherein the porosity is 15% by volume or more.

ADVANTAGE OF THE INVENTION According to this invention, the outstanding plate-shaped composite material which harmonized with respect to various characteristics, such as a dielectric constant and a dielectric loss tangent, can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an SEM photographed image of a porous inorganic fine particle aggregate formed by aggregation of inorganic fine particles having an average primary particle diameter of 5 to 200 nm (a photograph substituted for drawings).
2 is a graph showing the relationship between the filler content and dielectric loss tangent of plate-shaped composite materials according to Examples and Comparative Examples.
3 is a graph showing the relationship between the filler content and the coefficient of thermal expansion of plate-shaped composite materials according to Examples and Comparative Examples.

When this invention is demonstrated, although specific example is given and demonstrated, unless it deviates from the meaning of this invention, it is not limited to the following content, It can change suitably and implement.

≪Plate-shaped composite material≫

A plate-shaped composite material (hereinafter, sometimes abbreviated as “composite material”), which is an aspect of the present invention, is a plate-shaped composite material containing a fluorine-based resin and a filler, and the filler includes an “average primary particle diameter of 5 to A porous inorganic fine particle aggregate formed by agglomeration of 200 nm inorganic fine particles (hereinafter, may be abbreviated as "inorganic fine particle aggregate")", and "non-porous inorganic fine particle having an average primary particle diameter of 0.2 to 50 μm (hereinafter, " It may be abbreviated as "non-porous inorganic fine particles"), and the total content of the inorganic fine particle aggregate and the non-porous inorganic fine particle is 20 to 90 mass% of the composite material, and the inorganic fine particle aggregate and the non-porous inorganic fine particle It is characterized in that the mass ratio of the content of the non-porous inorganic fine particles to the total content (content of the non-porous inorganic fine particles/(content of the inorganic fine particle aggregate + the non-porous inorganic fine particle content)) is 0.15 to 0.90.

As a result of repeated intensive studies on plate-shaped composite materials that can be used as substrates such as microstrip patch antennas, the present inventors have found that, by including inorganic fine particle aggregates and non-porous inorganic fine particles within the above range, the advantages of each filler are It has been found to be an excellent composite material that is appropriately expressed and harmonized with various characteristics such as relative permittivity and dielectric loss tangent.

Hereinafter, "fluororesin" and "fillers", such as "inorganic fine particle aggregate" and "nonporous inorganic fine particle", etc. are demonstrated in detail.

<Fluorine-based resin>

The kind of fluororesin is not specifically limited, The fluororesin used for a board|substrate etc. can be employ|adopted suitably.

Examples of the fluorine-based resin are usually polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), tetrafluoroethylene/hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTEF), tetra fluoroethylene/ethylene copolymer (ETFE), chlorotrifluoroethylene/ethylene copolymer (ECTFE), and polyvinylidene fluoride (PVDF), but PTFE is particularly preferred. These can be used individually or in combination of 2 or more types.

It is preferable that the fluorine-based resin is "fibrillated (fibrous structure)". It is more preferable that the fibers in fibrillation are oriented not only in one direction but in multiple directions, and it is particularly preferable that the fibrils and inorganic fine particle aggregates described later are connected to form a "three-dimensional fine mesh structure" do. When the fluorine-based resin is fibrillated, particularly when a three-dimensional fine mesh structure is formed, excellent mechanical strength and dimensional stability can be ensured as a composite material. In addition, about the fibrillation of a fluororesin, etc., it can confirm by surface observation by SEM etc. In addition, the fibrillation of the fluorine-based resin can be advanced, for example, by applying a shear force, more specifically, the multi-step rolling described later, and the three-dimensional fine mesh structure is a two-way (異) described later.方向) performing by multi-stage rolling is mentioned.

<Filler>

The composite material contains inorganic fine particle aggregates and non-porous inorganic fine particles as fillers. The inorganic fine particle aggregate is specifically as shown in the SEM image of FIG. 1 , and a plurality of inorganic fine particles are fused to form an aggregate. and having voids between the inorganic fine particles and being porous. In addition, the inorganic fine particles in the aggregate may be fused at the time of formulation, and the fusion may be released by subsequent mixing with a fluororesin or the like.

On the other hand, the "non-porous" of the non-porous inorganic fine particles is an expression for the characteristic "porous" in the inorganic fine particles, and the non-porous inorganic fine particles should just be inorganic fine particles that are not "porous". That is, the non-porous inorganic fine particles do not have to have no pores, and may have pores as long as it is not recognized as "porous".

Hereinafter, the "inorganic fine particle aggregate" and the "non-porous inorganic fine particle" will be described in detail.

(Inorganic fine particle aggregate)

The material of the inorganic fine particles in the inorganic fine particle aggregate is usually oxides of typical elements such as silicon oxide (silicon monoxide, silicon dioxide (silica), etc.) and aluminum oxide (alumina) (composite oxides are also included); transition metal oxides (composite oxides are also included), such as titanium oxide (titanium dioxide (titania) etc.), iron oxide, and zirconium oxide (zirconium dioxide (zirconia)); Although nitrides of typical elements, such as boron nitride and silicon nitride, etc. are mentioned, The oxide of a typical element is preferable, and silicon dioxide (silica) is especially preferable. If it is the oxide of a typical element, the dielectric constant of a composite material can be suppressed very low, and a composite material can be manufactured at lower cost. In addition, although the crystallinity of an inorganic fine particle is although it does not specifically limit, In the case of silicon dioxide, it is amorphous normally.

The average primary particle diameter of the inorganic fine particles in the inorganic fine particle aggregate is 5 to 200 nm, but preferably 10 nm or more, more preferably 15 nm or more, still more preferably 20 nm or more, and preferably 150 nm or more. or less, more preferably 120 nm or less, still more preferably 100 nm or less, particularly preferably 80 nm or less, and most preferably 70 nm or less. If it is within the above range, it is difficult to destroy the inorganic fine particle aggregate even when processing such as mixing, molding, rolling, etc. is performed, good voids can be ensured between the inorganic fine particles, and it is easy to ensure a smooth surface as a plate-shaped composite material. . In addition, let the average primary particle diameter of the inorganic fine particle in an inorganic fine particle aggregate be the numerical value obtained by measuring a particle diameter by observation by SEM, and averaging the measured value. Specifically, it is a procedure in which 100 inorganic fine particle aggregates are randomly selected, each particle diameter (the long diameter of the particle) is measured, and the obtained particle diameter is averaged to obtain a numerical value.

The average particle diameter of the primary aggregate of inorganic fine particles in the inorganic fine particle aggregate is usually 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, and usually 400 nm or less, preferably 380 nm or less, More preferably, it is 350 nm or less. The average particle diameter of the secondary aggregate (aggregate of the primary aggregate) of the inorganic fine particles in the inorganic fine particle aggregate is usually 0.1 µm or more, preferably 1 µm or more, more preferably 2 µm or more, and is usually 100 µm or less, preferably Preferably it is 90 micrometers or less, More preferably, it is 80 micrometers or less. Moreover, it is preferable that the inorganic fine particle aggregate in a composite material is in the state of a secondary aggregate. If it is a state of a secondary aggregate, it will become easy to form the above-mentioned three-dimensional fine mesh structure. In addition, the average particle diameter of a primary aggregate and the average particle diameter of a secondary aggregate are computable by the method similar to the average primary particle diameter of the inorganic fine particle in the inorganic fine particle aggregate mentioned above.

The BET specific surface area of the inorganic fine particle aggregate is usually 10 m/g or more, preferably 20 m/g or more, more preferably 30 m/g or more, still more preferably 40 m/g or more, and usually 250 m/g or more. g or less, preferably 240 m 2 /g or less, more preferably 210 m 2 /g or less, still more preferably 150 m 2 /g or less, particularly preferably 80 m 2 /g or less. If it is within the above range, a high porosity can be ensured as a composite material, and an increase in dielectric loss tangent can be suppressed. In particular, when the BET specific surface area is too high, the dielectric loss tangent of the composite material tends to be high. In addition, the BET specific surface area of the inorganic fine particle aggregate is a numerical value calculated by substituting the gas adsorption amount measured by the gas adsorption method (especially nitrogen adsorption isotherm) into the BET equation, make it as

The inorganic fine particle aggregate has an apparent specific gravity of usually 10 g/L or more, preferably 20 g/L or more, more preferably 30 g/L or more, still more preferably 40 g/L or more, and usually 100 g/L or more. or less, preferably 90 g/L or less, more preferably 80 g/L or less, still more preferably 70 g/L or less, particularly preferably 60 g/L or less. If it is in the said range, a high porosity can be ensured as a composite material, and it becomes difficult to destroy an inorganic fine particle aggregate. In addition, the apparent specific gravity of the inorganic fine particle aggregate is measured by filling the inorganic fine particle aggregate in a container capable of measuring a volume such as a 250 mL measuring cylinder, and measuring the packing mass (X g) and filling volume (Y mL) of the inorganic fine particle aggregate. and divide the filling mass by the filling volume ([apparent specific gravity (g/L)]=X/Y×1000).

Examples of the inorganic fine particle aggregate include Mizukasil series (manufactured by Mizusawa Chemical Industry Co., Ltd.), Silicia series (manufactured by Fuji Silicia, Ltd.), AEROSIL series (manufactured by Nippon Aerosil Corporation), Nipsil series (manufactured by Tosoh Silica Corporation), and the like. A commercial item can be used suitably, Especially, the fumed silica of AEROSIL series (made by Nippon Aerosil Corporation) is especially preferable.

(non-porous inorganic fine particles)

The material of the non-porous inorganic fine particles is usually an oxide (composite oxide is also included) of typical elements such as silicon oxide (silicon monoxide, silicon dioxide (silica), etc.) and aluminum oxide (alumina); transition metal oxides (composite oxides are also included), such as titanium oxide (titanium dioxide (titania) etc.), iron oxide, and zirconium oxide (zirconium dioxide (zirconia)); and nitrides of typical elements such as boron nitride and silicon nitride, and among them, silicon oxide is preferable. Further, examples of the composite oxide include cordierite, talc, wollastonite, mullite, steatite, forsterite, and the like. The material of the non-porous inorganic fine particles is not limited to one type, and two or more types may be combined.

The average primary particle diameter of the non-porous inorganic fine particles is 0.2 to 50 µm, but preferably 0.3 µm or more, more preferably 0.4 µm or more, still more preferably 0.5 µm or more, preferably 40 µm or less, more preferably preferably 30 μm or less, more preferably 20 μm or less, particularly preferably 10 μm or less, most preferably 5 μm or less. If it is within the above range, a suitable specific surface area can be obtained, a good dielectric loss tangent can be ensured, the surface of the composite material can be easily made a smooth surface, and the material is more suitable for a high frequency substrate. In addition, let the average primary particle diameter of nonporous inorganic fine particles be the numerical value obtained by measuring a particle diameter by observation by SEM, and averaging the measured value. Specifically, it is a procedure in which 100 inorganic fine particle aggregates are randomly selected, each particle diameter (the long diameter of the particle) is measured, and the obtained particle diameter is averaged to obtain a numerical value.

The nonporous inorganic fine particles have a BET specific surface area of usually 0.1 m 2 /g or more, preferably 0.5 m 2 /g or more, more preferably 1 m 2 /g or more, still more preferably 2 m 2 /g or more, and usually 30 m 2 /g or less, preferably 25 m 2 /g or less, more preferably 20 m 2 /g or less, still more preferably 15 m 2 /g or less, particularly preferably 10 m 2 /g or less. If it is within the above range, good dielectric loss tangent can be ensured, the surface of the composite material can be easily made a smooth surface, and the material is more suitable for a high frequency substrate. In addition, the BET specific surface area of the non-porous inorganic fine particles is a numerical value calculated by substituting the gas adsorption amount measured by the gas adsorption method (especially the nitrogen adsorption isotherm) into the BET formula, and is a numerical value before use in the manufacture of the composite material. to indicate

The dielectric constant of the nonporous inorganic fine particles is usually 10 or less, preferably 8 or less, more preferably 7 or less, still more preferably 6 or less, particularly preferably 5 or less, and usually 3 or more. In addition, let the dielectric constant of a nonporous inorganic fine particle be the numerical value determined by the method based on Japanese Industrial Standard JIS C2565.

Examples of commercially available nonporous inorganic fine particles include fused silica such as SFP-130MC, SFP-30M, and FB-3SDC manufactured by Denka Corporation, cordierite powder FINE type manufactured by AGC Ceramics, and cordierite such as ELP-150N and ELP-325N. and talc, such as boron nitride such as FS-1, HP-P1, and HP40J series manufactured by Kokintetsu Mizushima, and Nanoace D-600, D-800, D-1000, and FG-15 manufactured by Nippon Talc. .

(Other fillers)

The composite material may contain an inorganic fine particle aggregate and a filler that does not correspond to the non-porous inorganic fine particle (hereinafter, it may be abbreviated as "other filler"), and only the inorganic fine particle aggregate and the non-porous inorganic fine particle as the filler. It is also preferable to include. Examples of other fillers include particulate fillers and fibrous fillers. Examples of particulate fillers include solid carbon such as carbon black and graphite; Hollow inorganic particles, such as a silica balloon and a glass balloon, etc. are mentioned, As a fibrous filler, glass fiber, carbon fiber, etc. are mentioned, for example. Other fillers are not limited to one type, You may combine two or more types.

It is preferable that the surface of the filler (including inorganic fine particle aggregates and non-porous inorganic fine particles) is modified with a surface modifying agent having a hydrophobic group (hereinafter sometimes abbreviated as "surface modifying agent").

Hereinafter, the modification by the "surface modifier" will be described in detail.

Examples of the hydrophobic group of the surface modifier include a fluoro group (-F), a hydrocarbon group (-C _n H _2n+1 (n=1 to 30)), and the like. Also, the fluoro group which emits liquid repellency is especially preferable.

The surface modifier may be chemically adsorbed (reacted) with respect to the surface of the filler, may be physically adsorbed to the surface of the filler, or may be a low molecular weight compound or a high molecular compound. The surface modifier chemically adsorbed (reacted) to the surface of the filler usually has a reactive functional group that reacts with the surface functional group of the filler (such as a hydroxyl group (-OH)), and the reactive functional group is an alkoxysilyl group (- SiOR (R has 1 to 6 carbon atoms), a chlorosilyl group (-SiCl), a bromosilyl group (-SiBr), a hydrosilyl group (-SiH), and the like. In addition, although a well-known method can be employ|adopted suitably as a method of modifying the surface of a filler with a surface modifier, making a filler and a surface modifier contact is mentioned.

The surface modifying agent can be used alone or in combination of two or more. For example, after reacting the surface modifying agent of a low molecular compound having a reactive functional group with the surface of the filler, a surface modifying agent of a high molecular compound having a hydrophobic group thereon is physically applied. may be adsorbed. If the material of the filler is silicon dioxide (silica) or the like, it may dissolve (decompose) when exposed to a basic aqueous solution.

The thermal decomposition temperature of the surface modifier is usually 250°C or higher, preferably 300°C or higher, more preferably 350°C or higher, still more preferably 360°C or higher, and particularly preferably 370°C or higher. If it is within the above range, decomposition can be suppressed even if a process, such as high temperature heating, is performed. The thermal decomposition temperature of the surface modifier is a temperature at which the weight decreases by 5% when the temperature is raised at 20°C/min by thermogravimetric reduction analysis (TG-DTA).

Examples of the surface modifying agent for a low molecular weight compound having a fluoro group and a reactive functional group include those represented by the following formula. In addition, the compound represented by the following formula is commercially available, and it can obtain suitably and can use it as a surface modifier.

Examples of the surface modifying agent for the polymer compound having a fluoro group include those represented by the following formula.

A commercially available solution may be used as the surface modifier, and suitable examples include T1770 by Tokyo Kasei Kogyo Co., Ltd. and Novec (registered trademark) 2202 by 3M. Novec (registered trademark) 2202 contains a high molecular compound having a fluoro group, and it is published that "fluoroalkylsilane polymer" is mix|blended. When Novec (registered trademark) 2202 is used as a surface modifier, it has a feature that it is easy to suppress the critical liquid-repellent tension of the composite material by a relatively simple operation.

The content of the surface modifier in the filler (content of organic matter) is usually 0.1 mass% or more, preferably 1 mass% or more, more preferably 2 mass% or more, still more preferably 3 mass% or more, particularly preferably Preferably it is 4 mass % or more, Usually 50 mass % or less, Preferably it is 40 mass % or less, More preferably, it is 30 mass % or less, More preferably, it is 25 mass % or less, Especially preferably, it is 20 mass % or less.

(composite material)

In the composite material, the total content of the inorganic fine particle aggregate and the non-porous inorganic fine particle is 20 to 90 mass %, and the "total content" refers to the content of the inorganic fine particle aggregate and the non-porous inorganic fine particle when the composite material is 100 mass %. The total content of the content is meant, and when the inorganic fine particle aggregate and/or the non-porous inorganic fine particles contain two or more types, all these total contents are meant. The total content of the inorganic fine particle aggregate and the non-porous inorganic fine particles is preferably 30 mass % or more, more preferably 40 mass % or more, still more preferably 50 mass % or more, preferably 80 mass % or less, more preferably Preferably it is 75 mass % or less, More preferably, it is 70 mass % or less. Further, when the total of the fluorine-based resin and the inorganic fine particle aggregate and the non-porous inorganic fine particle is 100 parts by mass, the total content of the inorganic fine particle aggregate and the non-porous inorganic fine particle is usually 20 to 90 parts by mass, preferably 30 parts by mass or more. , More preferably, it is 40 mass parts or more, More preferably, it is 50 mass parts or more, Preferably it is 80 mass parts or less, More preferably, it is 75 mass parts or less, More preferably, it is 70 mass parts or less. If it is in the said range, it will become easy to achieve harmony with respect to various characteristics, such as a dielectric constant and a dielectric loss tangent.

The composite material has a mass ratio of the content of the non-porous inorganic fine particles to the total content of the inorganic fine particle aggregate and the non-porous inorganic fine particle (the content of the non-porous inorganic fine particle / (the content of the inorganic fine particle aggregate + the non-porous inorganic fine particle) content)) is 0.15 to 0.90, preferably 0.2 or more, more preferably 0.3 or more, still more preferably 0.4 or more, most preferably 0.5 or more, preferably 0.8 or less, more preferably 0.75 or less; More preferably, it is 0.7 or less, and most preferably, it is 0.65 or less.

The total content of the filler in the composite material is usually 20 to 90 mass %, preferably 30 mass % or more, more preferably 40 mass % or more, still more preferably 50 mass % or more, and preferably 80 mass % or more. % or less, more preferably 75 mass% or less, still more preferably 70 mass% or less. Further, when the total of the fluororesin and the filler is 100 parts by mass, the total content of the filler is usually 20 to 90 parts by mass, preferably 30 parts by mass or more, more preferably 40 parts by mass or more, still more preferably It is 50 mass parts or more, Preferably it is 80 mass parts or less, More preferably, it is 75 mass parts or less, More preferably, it is 70 mass parts or less. If it is in the said range, it will become easy to achieve harmony with respect to various characteristics, such as a dielectric constant and a dielectric loss tangent.

The composite material may contain materials other than the above-described fluorine-based resin and filler (including inorganic fine particle aggregates and non-porous inorganic fine particles), but the total content of the fluorine-based resin and filler in the composite material is usually 60% by mass or more. , Preferably it is 70 mass % or more, More preferably, it is 80 mass % or more, More preferably, it is 90 mass % or more, Especially preferably, it is 100 mass %.

The shape of the composite material is plate-like, and the thickness is usually 2.0 to 3000 µm, preferably 10 µm or more, more preferably 50 µm or more, still more preferably 80 µm or more, and most preferably 100 µm or more. , preferably 2000 μm or less, more preferably 1000 μm or less, still more preferably 800 μm or less, particularly preferably 600 μm or less, most preferably 400 μm or less. If it is within the above range, it is possible to ensure a good dielectric constant and the like as a composite material.

The dimensions (maximum diameter, longitudinal or transverse length) of the composite material are usually 20 to 1500 mm, but preferably 30 mm or more, more preferably 40 mm or more, still more preferably 50 mm or more, and most preferably It is 60 mm or more, Preferably it is 1400 mm or less, More preferably, it is 1300 mm or less.

The porosity of the composite material is usually 10 to 90% by volume, but preferably 15% by volume or more, more preferably 20% by volume or more, still more preferably 30% by volume or more, particularly preferably 40% by volume or more, Preferably it is 80 volume% or less, More preferably, it is 70 volume% or less, More preferably, it is 60 volume% or less. If it is in the said range, characteristics, such as a dielectric constant and thermal expansion coefficient, favorable as a composite material can be ensured. In addition, the porosity of the composite material is a numerical value calculated by measuring the volume of the composite material, the specific gravity and mass of the fluororesin (mixed mass), and the specific gravity and mass (mixing mass) of the filler, and substituting it into the following formula.

[Porosity (volume %)] = ([volume of composite material]-[mass of fluororesin / specific gravity of fluororesin]-[mass of filler / specific gravity of filler])/[volume of composite material] x 100

The dielectric constant (frequency: 10 GHz) of the composite material is usually 3.0 or less, preferably 2.60 or less, more preferably 2.40 or less, still more preferably 2.00 or less, particularly preferably 1.80 or less, and usually 1.55 or more. The relative dielectric constant of the composite material is a numerical value of the real part εr' calculated by measuring the complex dielectric constant by the cavity resonator perturbation method (measurement frequency: 10 GHz).

The dielectric loss tangent (frequency: 10 GHz) of the composite material is usually 0.01 or less, preferably 0.008 or less, more preferably 0.006 or less, still more preferably 0.004 or less, particularly preferably 0.002 or less, and usually 0.0005 or more. In addition, the relative permittivity of the composite material is determined by measuring the complex permittivity by the cavity resonator perturbation method (measurement frequency: 10 GHz) and calculated by measuring the ratio of the imaginary part (εr') to the real part (εr') (εr"/εr) ').

The coefficient of thermal expansion (Z-axis direction) of the composite material is usually 100 ppm/K or less, preferably 90 ppm/K or less, more preferably 80 ppm/K or less, still more preferably 70 ppm/K or less, particularly preferably It is preferably 60 ppm/K or less, most preferably 50 ppm/K or less, and is usually 5 ppm/K or more. In addition, the thermal expansion coefficient (Z-axis direction) of the composite material was determined by laser interferometry (laser thermal extensometer, measurement temperature range: -50 to 200°C, temperature increase rate: 2°C/min, atmosphere: He, load: 17 g) It is set as the numerical value computed from the formula based on Japanese Industrial Standard JIS R3251-1990 using

The tensile strength of the composite material is usually 1 to 50 MPa, preferably 5 MPa or more, more preferably 7 MPa or more, still more preferably 10 MPa or more, preferably 45 MPa or less, more preferably 40 MPa or more. Hereinafter, more preferably, it is 35 MPa or less. The tensile strength is a numerical value measured in accordance with the method specified in Japanese Industrial Standard JIS K7161 (refer to the detailed conditions mentioned later.).

The tensile modulus of elasticity of the composite material is usually 0.05 to 1 GPa, preferably 0.08 GPa or more, more preferably 0.1 GPa or more, still more preferably 0.15 GPa or more, preferably 0.8 GPa or less, more preferably 0.6 GPa or more. Hereinafter, more preferably, it is 0.4 GPa or less. The tensile modulus of elasticity is a numerical value measured in accordance with the method specified in Japanese Industrial Standards JIS K7161 (refer to the detailed conditions mentioned later.).

<Use of Composite Material>

The use of the composite material is not particularly limited, but preferably an electronic circuit board, more preferably a circuit board for a mobile phone or a computer, and a microstrip patch antenna board for millimeter wave radar. That is, a substrate (hereinafter, sometimes abbreviated as "substrate") made of the above-described composite material is also mentioned as an aspect of the present invention.

Although the substrate is made of a composite material, it is preferable to have a layer (hereinafter, sometimes abbreviated as "resin layer") made of a thermoplastic resin adhered to one or both surfaces of the composite material. As resin, a fluorine-type resin is especially preferable.

As the fluorine-based resin, polytetrafluoroethylene (PTFE, melting point: 327°C), perfluoroalkoxyalkane (PFA, melting point: 310°C), tetrafluoroethylene/hexafluoropropylene copolymer (FEP, melting point: 260°C) ), polychlorotrifluoroethylene (PCTEF, melting point: 220°C), tetrafluoroethylene-ethylene copolymer (ETFE, melting point: 270°C), chlorotrifluoroethylene-ethylene copolymer (ECTFE, melting point: 270°C) ), polyvinylidene fluoride (PVDF, melting point: 151 to 178°C), with PTFE and PFA being particularly preferred. These can be used individually or in combination of 2 or more types.

The thickness of the resin layer is usually 0.050 to 30 µm, but preferably 0.100 µm or more, more preferably 0.40 µm or more, still more preferably 1.0 µm or more, most preferably 1.5 µm or more, and preferably 20 µm or more. or less, more preferably 10 µm or less, still more preferably 8.0 µm or less, particularly preferably 6.0 µm or less, and most preferably 5.0 µm or less. The substrate is exposed to various chemicals used in the manufacturing process of antennas and the like. For example, when exposed to a treatment liquid with high permeability, the treatment liquid permeates therein, resulting in poor appearance or a change in characteristics of the substrate. Since the resin layer also has a function of suppressing penetration of the processing liquid, if it is within the above range, peeling of the conductor layer or the like can be effectively suppressed, and when exposed to a processing liquid with high permeability used in the manufacture of electronic circuit boards, etc. Even if it is, it becomes difficult to generate|occur|produce an appearance defect or a characteristic change. In addition, the thickness of a resin layer shall mean the numerical value which measured about 5-10 points|pieces with respect to the distance from the thickness direction terminal of a resin layer to the interface of a composite material and a resin layer, and averaged these.

The resin layer may be laminated not only on one side of the composite material (adhesive), but also on both surfaces of the composite material.

The peel strength of the composite material and the resin layer is usually 0.2 to 2.5 N/mm, preferably 0.3 N/mm or more, more preferably 0.4 N/mm or more, still more preferably 0.5 N/mm or more, preferably is 2.4 N/mm or less, more preferably 2.2 N/mm or less, still more preferably 2 N/mm or less. Peel strength is set as the numerical value measured based on the method prescribed|regulated to Japanese Industrial Standards JIS C6481:1996 (refer the thing mentioned later for detailed conditions.).

A conductor layer is normally formed in a board|substrate, and a conductor layer is a metal layer normally. Moreover, when it has a resin layer, a conductor layer is laminated|stacked on the resin layer.

As for the metal species of a metal layer, normally gold (Au), silver (Ag), platinum (Pt), copper (Cu), aluminum (Al), the alloy containing these metal species, etc. are mentioned.

The thickness of the metal layer is usually 5 µm or more, preferably 10 µm or more, more preferably 15 µm or more, and is usually 50 µm or less, preferably 45 µm or less, and more preferably 40 µm or less.

The maximum height Rz of the contact surface of the conductor layer to the composite material or resin layer is usually 0.020 µm or more, preferably 0.050 µm or more, more preferably 0.10 µm or more, still more preferably 0.20 µm or more, particularly preferably It is 0.30 micrometer or more, Usually 10 micrometers or less, Preferably it is 8.0 micrometers or less, More preferably, it is 6.0 micrometers or less, More preferably, it is 4.0 micrometers or less, Especially preferably, it is 2.0 micrometers or less. In addition, "maximum height Rz" means a numerical value determined by a method based on Japanese industrial standard JIS B0601:2013 (It is a Japanese industrial standard created without changing technical content with respect to International Organization for Standardization Standard ISO4287.) do. In addition, "the maximum height Rz of the contact surface of the conductor layer with respect to the composite material or resin layer" is directly measured, and the maximum height Rz of the material used for the conductor layer may be used as it is.

The thickness ((thickness of resin layer)-(maximum height Rz of conductor layer)) obtained by subtracting the maximum height Rz of the conductor layer from the thickness of the resin layer is usually 0.005 µm or more, preferably 0.010 µm or more, more preferably 0.050 µm or more. μm or more, more preferably 0.10 μm or more, particularly preferably 0.50 μm or more, usually 29.98 μm or less, preferably 20 μm or less, more preferably 15 μm or less, still more preferably 10 μm or less, particularly preferably preferably 5.0 μm or less. If it is within the above range, since the thickness of the resin layer is sufficiently ensured, even when exposed to a highly permeable processing liquid used for manufacturing an electronic circuit board, etc., it becomes difficult to generate an appearance defect or a change in characteristics.

<Method for manufacturing composite material>

The composite material is manufactured by a manufacturing method (hereinafter, sometimes abbreviated as "manufacturing method of a composite material") including the following resin preparation process, filler preparation process, mixing process, molding process, and rolling process. it is preferable

- A resin preparation step of preparing a fluorine-based resin (hereinafter, it may be abbreviated as a “resin preparation step”).

- Filler preparation process of preparing a filler (Hereinafter, it may abbreviate as "filler preparation process".).

- A mixing step of mixing the fluororesin, the filler, and a volatile additive to obtain a precursor composition (hereinafter, it may be abbreviated as a “mixing step”).

- A shaping|molding process of shaping|molding the said precursor composition and obtaining a to-be-rolled object which can be rolled (Hereinafter, it may abbreviate as "molding process".).

- A rolling process of rolling the to-be-rolled object to obtain a composite material (hereinafter, it may be abbreviated as "rolling process").

Hereinafter, "resin preparation process", "filler preparation process", "mixing process", "forming process", "rolling process", etc. are demonstrated in detail.

Although a resin preparation process is a process of preparing a fluororesin, you may obtain a fluororesin, or you may manufacture it by yourself. The average particle diameter (median diameter d50) of the prepared fluorine-based resin granulated product (particles after secondary particles) is usually 0.5 µm or more, preferably 1.0 µm or more, more preferably 10 µm or more, More preferably, it is 30 micrometers or more, Usually 700 micrometers or less, Preferably it is 300 micrometers or less, More preferably, it is 150 micrometers or less, More preferably, it is 100 micrometers or less, Especially preferably, it is 50 micrometers or less. It becomes easy to disperse|distribute a fluororesin and a filler uniformly as it is in an above-mentioned range. In addition, the granulated material of a fluororesin can be determined by the method based on Japanese Industrial Standard JIS Z8825:2001.

Although a filler preparation process is a process of preparing a filler, a filler (an inorganic fine particle aggregate and non-porous inorganic fine particle are included.) may be obtained or you may manufacture by yourself. The average particle diameter (median diameter d50) of the filler to be prepared, especially the granulated material of the inorganic fine particle aggregate (particles after the secondary particles) is usually 0.1 µm or more, preferably 0.5 µm or more, more preferably 1 µm or more, further Preferably it is 3 micrometers or more, Usually 500 micrometers or less, Preferably it is 200 micrometers or less, More preferably, it is 100 micrometers or less, More preferably, it is 50 micrometers or less, Especially preferably, it is 20 micrometers or less. The average particle diameter (median diameter d50) of the granulated material of the nonporous inorganic fine particles (particles after the secondary particles) is usually 1 µm or more, preferably 3 µm or more, more preferably 5 µm or more, still more preferably 10 It is more than micrometer, Usually 2000 micrometers or less, Preferably it is 1000 micrometers or less, More preferably, it is 500 micrometers or less, More preferably, it is 100 micrometers or less, Especially preferably, it is 50 micrometers or less. It becomes easy to disperse|distribute a fluororesin and a filler uniformly as it is in an above-mentioned range. In addition, the granulated material of a filler can be determined by the method based on Japanese Industrial Standard JIS Z8825:2001.

Moreover, it is preferable that the surface of a filler is modified with the above-mentioned surface modifier.

The particle diameter ratio (average particle diameter of fluorine resin (median diameter d50)/average particle diameter of inorganic fine particle aggregates (median diameter d50)) of the average particle diameter of the granulated material of the fluorine-based resin to be prepared and the granulated material of the inorganic fine particle aggregate is usually 150 or less, preferably 100 or less, more preferably 60 or less, still more preferably 40 or less, particularly preferably 30 or less, most preferably 10 or less, and usually 1 or more. The particle diameter ratio of the average particle diameter of the prepared granulated material of the fluorine-based resin and the granulated material of non-porous inorganic fine particles (average particle diameter of the fluorine-based resin (median diameter d50)/average particle diameter of the non-porous inorganic fine particles (median diameter d50)) is, It is usually 500 or less, preferably 300 or less, more preferably 200 or less, still more preferably 100 or less, particularly preferably 50 or less, most preferably 30 or less, and usually 0.01 or more. It becomes easy to disperse|distribute a fluororesin and a filler uniformly as it is in an above-mentioned range.

The mixing step is a step of obtaining a precursor composition by mixing a fluororesin, a filler, and a volatile additive, and mixing can be performed by appropriately employing a known method such as a dry or wet method, a mixer, or the like.

The rotation speed (circumferential speed) of a stirrer etc. in the case of a dry type is 0.5 m/sec or more normally, Preferably it is 1 m/sec or more, More preferably, it is 5 m/sec or more, More preferably, it is 10 m. /sec or more, particularly preferably 15 m/sec or more, usually 200 m/sec or less, preferably 180 m/sec or less, more preferably 140 m/sec or less, still more preferably 100 m/sec or less , particularly preferably 50 m/sec or less, and most preferably 20 m/sec or less. It becomes easy to disperse|distribute a fluororesin and a filler uniformly as it is in an above-mentioned range.

In the case of dry mixing, the mixing time is usually at least 10 seconds, preferably at least 20 seconds, more preferably at least 30 seconds, still more preferably at least 40 seconds, particularly preferably at least 1 minute, most preferably over 5 minutes. or more, usually 60 minutes or less, preferably 50 minutes or less, more preferably 40 minutes or less, still more preferably 30 minutes or less, particularly preferably 20 minutes or less, and most preferably 15 minutes or less. It becomes easy to disperse|distribute a fluororesin and a filler uniformly as it is in an above-mentioned range.

The rotation speed (circumferential speed) of the stirrer or the like in the wet case is usually 1 m/sec or more, preferably 5 m/sec or more, more preferably 10 m/sec or more, still more preferably 15 m/sec or more, It is particularly preferably 20 m/sec or more, most preferably 25 m/sec or more, usually 160 m/sec or less, preferably 130 m/sec or less, more preferably 100 m/sec or less, still more preferably is 80 m/sec or less, particularly preferably 60 m/sec or less, and most preferably 40 m/sec or less. It becomes easy to disperse|distribute a fluororesin and a filler uniformly as it is in an above-mentioned range.

In the case of wet mixing, the mixing time is usually 5 seconds or longer, preferably 10 seconds or longer, more preferably 20 seconds or longer, still more preferably 30 seconds or longer, particularly preferably 40 seconds or longer, most preferably 50 seconds or longer. or more, usually 60 minutes or less, preferably 50 minutes or less, more preferably 40 minutes or less, still more preferably 20 minutes or less, particularly preferably 10 minutes or less, and most preferably 5 minutes or less. It becomes easy to disperse|distribute a fluororesin and a filler uniformly as it is in an above-mentioned range.

The volatile additive has a function of sufficiently enclosing voids in the composite material by finally volatilizing and removing it. The volatile additive means a compound that has a boiling point of 30 to 300° C. and is liquid at room temperature (25° C.), and the boiling point of the volatile additive is preferably 50° C. or more, more preferably 100° C. or more, still more preferably It is 200 degreeC or more, Preferably it is 280 degrees C or less, More preferably, it is 260 degrees C or less, More preferably, it is 240 degrees C or less.

Examples of the volatile additive include hydrocarbons, ethers, esters, and alcohols with low reactivity, but aliphatic saturated hydrocarbons are preferable. Specifically, hexane (boiling point: 69 °C), heptane (boiling point: 98 °C), octane (boiling point: 126 °C), nonane (boiling point: 151 °C), decane (boiling point: 174 °C), undecane (boiling point: 196 °C) ), dodecane (boiling point: 215°C), tridecane (boiling point: 234°C), tetradecane (boiling point: 254°C), and the like. These can be used individually or in combination of 2 or more types.

The amount of the volatile additive added is usually 1 part by mass or more, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 20 parts by mass or more, when the total of the fluororesin and the filler is 100 parts by mass. , Particularly preferably 30 parts by mass or more, usually 200 parts by mass or less, preferably 150 parts by mass or less, more preferably 130 parts by mass or less, still more preferably 110 parts by mass or less, particularly preferably 100 parts by mass or less. is below. If it is in the said range, good porosity can be ensured as a composite material.

It is preferable that a mixing process adds and mixes a solvent in addition to a fluororesin, a filler, and a volatile additive. The solvent has a function of making the precursor composition into a paste and uniformly dispersing it. As a solvent, lower alcohols, such as water, methanol, ethanol, isopropanol, and a butanol, etc. are mentioned. These can be used individually or in combination of 2 or more types.

The molding step is a step of obtaining a rollable product by molding the precursor composition. Examples of the molding machine used in the molding step include an FT die (fishtail extrusion die), a press machine, an extrusion molding machine, and a calender roll. In particular, FT dice are preferable.

The rolling process is a process of obtaining a composite material by rolling the rolled object, preferably "multi-step rolling" in which the operation of laminating the obtained rolled object and performing rolling as the rolled object is repeated a plurality of times, and in the rolling direction of the previous time It is especially preferable that it is "two-way multi-step rolling" in which the to-be-rolled object is rolled in different directions. The two-way multi-step rolling includes, for example, repeating the operation of stacking rolled products so as to face the same rolling direction to obtain a rolled product, and rotating the rolled product by 90° from the previous rolling direction to perform rolling. .

The number of laminations of the rolled products in the multistage rolling is usually 2 or more, preferably 3 or more, more preferably 4 or more, still more preferably 10 or more, particularly preferably 30 or more, and usually 2000 or less, preferably It is 1000 or less, More preferably, it is 700 or less, More preferably, it is 500 or less, Especially preferably, it is 300 or less.

The rolling ratio of the rolling step is usually 10 or more, preferably 20 or more, more preferably 40 or more, still more preferably 50 or more, particularly preferably 100 or more, and usually 20000 or less, preferably 15000 or less, more Preferably it is 10000 or less, More preferably, it is 5000 or less, Especially preferably, it is 3000 or less.

As an apparatus used for a rolling process, a press machine, an extrusion molding machine, a rolling roll (for example, calender roll), etc. are mentioned.

The manufacturing method of a composite material or the manufacturing method of a board|substrate may include other processes, and the following process is mentioned specifically,.

- Additive removal process of removing the said volatile additive from the said rolling material (Hereinafter, it may abbreviate as "additive removal process".).

- A heat compression step of heating and compressing the rolled product (hereinafter, it may be abbreviated as a “heat compression step”).

- A resin layer forming step of forming a resin layer containing a fluorine-based resin on one or both surfaces of the composite material (hereinafter, may be abbreviated as “resin layer forming step”).

- Another layer forming step of forming a conductor layer on one or both surfaces of the composite material (hereinafter, it may be abbreviated as “conductor layer forming step”).

- A patterning process of patterning the conductor layer (hereinafter, it may be abbreviated as "patterning process").

Hereinafter, "additive removal process", "heat compression process", "resin layer formation process", "conductor layer formation process", "patterning process", etc. are demonstrated in detail.

Although an additive removal process is a process of removing the said volatile additive from a rolled product, the method of heating a rolled product in the heating furnace which can be used for drying normally is mentioned. Heating conditions can be suitably selected according to the boiling point of a volatile additive, etc.

A heat compression process is a process of heat-compressing a rolled product, Usually, the method of heat-compressing using a press machine etc. is mentioned. Although heat compression conditions can be selected suitably, it is preferable to apply pressure uniformly in-plane with respect to a rolled product.

The resin layer forming step is a step of forming a resin layer containing a fluorine-based resin on one or both surfaces of the composite material. A method of bonding by heating and pressurization is exemplified. By heating and pressurizing the resin film containing the fluorine-based resin, the fluorine-based resin permeates into the composite material, so that peeling of the conductor layer or the like can be effectively suppressed, and a good dielectric constant or the like can be secured as a composite material.

The thickness of the resin film containing the fluororesin is usually 0.050 µm or more, preferably 0.10 µm or more, more preferably 0.40 µm or more, still more preferably 1.0 µm or more, particularly preferably 1.5 µm or more, and usually 30 μm or less, preferably 20 μm or less, more preferably 10 μm or less, still more preferably 8.0 μm or less, particularly preferably 6.0 μm or less, most preferably 5.0 μm or less.

The pressure in the resin layer forming step is usually 0.01 MPa or more, preferably 0.10 MPa or more, more preferably 0.50 MPa or more, still more preferably 0.80 MPa or more, particularly preferably 1.00 MPa or more, and usually 50 MPa or more. Below, Preferably it is 40 MPa or less, More preferably, it is 30 MPa or less, More preferably, it is 20 MPa or less, Especially preferably, it is 10 MPa or less. If it is in the said range, peeling of a conductor layer etc. can be suppressed effectively, and favorable dielectric constant etc. can be ensured as a composite material.

The temperature in the resin layer forming step is usually 250°C or higher, preferably 280°C or higher, more preferably 300°C or higher, still more preferably 320°C or higher, particularly preferably 340°C or higher, and usually 500°C. Hereinafter, it is preferably 480°C or less, more preferably 460°C or less, still more preferably 440°C or less, and particularly preferably 420°C or less. If it is in the said range, peeling of a conductor layer etc. can be suppressed effectively, and favorable dielectric constant etc. can be ensured as a composite material.

The heat press time in the resin layer forming step is usually 1 second or longer, preferably 30 seconds or longer, more preferably 1 minute or longer, still more preferably 2 minutes or longer, particularly preferably 3 minutes or longer, usually It is 180 minutes or less, Preferably it is 120 minutes or less, More preferably, it is 60 minutes or less, More preferably, it is 30 minutes or less, Especially preferably, it is 20 minutes or less. If it is in the said range, peeling of a conductor layer etc. can be suppressed effectively, and favorable dielectric constant etc. can be ensured as a composite material.

As an apparatus used for a resin layer formation process, a press machine, a hot roll laminating machine, a belt press machine, etc. are mentioned.

The conductor layer forming step is a step of forming a conductor layer on one or both surfaces of the composite material, and examples of the method for forming the conductor layer include sputtering, plating, pressure bonding of metal foil, lamination, and the like.

The patterning process is a process of patterning the metal layer, and examples of the patterning process include an additive method using a photoresist or the like, a subtractive method by etching, and the like.

Example

The present invention will be more specifically described below with reference to examples, but changes may be made as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

<Example 1>

As an inorganic fine particle aggregate, hydrophilic fumed silica (manufactured by Nippon Aerosil, product number "AEROSIL50", BET specific surface area 50±15 m/g, average primary particle diameter 40 nm, secondary aggregate average particle diameter 0.2 μm) was used. , was modified using triethoxy-1H,1H,2H,2H-tridecafluoro-n-octylsilane (manufactured by Tokyo Kasei Kogyo Co., Ltd., part number "T1770") represented by the following formula as a surface modifier.

Specifically, to 832.9 g of isopropanol, 40.8 g of a surface modifier, 22.1 g of acetic acid, 43.2 g of pure water, and 80 g of inorganic fine particle aggregates were added and stirred for 24 hours to obtain a dispersion of inorganic fine particle aggregates. . Next, the dispersion was heated at 100°C for 1 hour and further heated at 200°C for 2 hours to obtain a surface-modified inorganic fine particle aggregate.

Next, fused silica (manufactured by Denka, product number "SFP-130MC", BET specific surface area of 6.2 m / g, average primary particle diameter of 0.6 µm) as non-porous inorganic fine particles, triethoxy-1H as a surface modifier, 1H,2H,2H-tridecafluoro-n-octylsilane (manufactured by Tokyo Chemical Industry Co., Ltd., part number "T1770") was used for modification.

Specifically, to 83.3 g of isopropanol, 6.8 g of a surface modifier, 2.1 g of acetic acid, 4.3 g of pure water, and 80 g of non-porous inorganic fine particles were added and stirred for 24 hours to obtain a dispersion of non-porous inorganic fine particles. Next, the dispersion was heated at 100°C for 1 hour and further heated at 200°C for 2 hours to obtain surface-modified nonporous inorganic fine particles.

Next, using a high-speed flow mixer, polytetrafluoroethylene (hereinafter, sometimes abbreviated as "PTFE"), the inorganic fine particle aggregate, the nonporous inorganic fine particle, and the volatile additive were mixed. Specifically, polytetrafluoroethylene (manufactured by Daikin, product number "Polypron PTFE F-104", average particle diameter of 550 µm) was prepared, and in consideration of the solid content, an inorganic surface modified with polytetrafluoroethylene After adding the particulate aggregate and non-porous inorganic particulate in a mass ratio of 44:46:10, stirring and mixing for 1 minute at a rotation speed of 14 m/sec and a temperature of 24°C, hydrocarbon oil (manufactured by ExxonMobil, part no. Isofar M”) was added so that 65 parts by mass when the total of polytetrafluoroethylene, the inorganic fine particle aggregate, and the non-porous inorganic fine particles were 100 parts by mass, the mixture was mixed at a rotation speed of 3 m/sec and a temperature of 24° C. for 5 minutes. to obtain a paste.

The paste was passed through a pair of rolling rolls to obtain an elliptical mother sheet (sheet-shaped molded article) having a thickness of 3 mm, a width of 10 to 50 mm, and a length of 150 mm, and a plurality of these mother sheets were produced. Next, two sheets of this mother sheet were laminated in the same rolling direction, and the laminate was passed between the rolling rolls in the previous rolling direction and rolled to produce a plurality of first rolled laminated sheets. Next, the rolling direction of the 1st rolling lamination|stacking sheet of 4 sheets was matched, it laminated|stacked, it rolled in the same direction, and produced the 2nd rolling lamination sheet. Thus, the process of laminating|stacking and rolling the sheet|seat was repeated 5 times in total, counting from lamination|stacking rolling of the mother sheet|seat, and the 3rd rolling lamination|stacking sheet was produced (the number of structural layers 512). Next, 4 sheets of the third rolled lamination sheet are laminated, the lamination sheet is rotated 90 degrees from the previous rolling direction while the sheet surface is parallel, and the lamination sheet is passed between the rolling rolls, and the gap between the rolling rolls is 0.5 mm It narrowed and rolled several times at a time to obtain a sheet with a thickness of about 0.18 mm. The obtained rolled laminated sheet was heated at 150 degreeC for 20 minutes, the volatile additive was removed, and the sheet-like composite material was produced.

Next, Fluon (registered trademark) PTFE Dispersion AD939E (manufactured by AGC, solid content: 60% by mass) is dip-coated on one side of the polyimide carrier so that the WET thickness is 4 μm, 150°C for 5 minutes, 380°C A resin film used as a resin layer was produced by heating in A Cu foil (JX Kinzoku Corporation, part number "BHFX-HS-92F") serving as a conductor layer is prepared, a resin film and Cu foil are laminated, and the resin conductor sheet is pressed with a press machine at a pressure of 6 MPa and a temperature of 360° C. for 10 minutes. was produced. This resin conductor sheet and the above-mentioned sheet-like composite material were laminated and press-molded at 360°C for 5 minutes at 4 MPa to prepare a laminated sheet with a conductor layer. Moreover, about the obtained laminated sheet, the peeling strength of the plate-shaped composite material mentioned later and a resin conductor sheet was measured. Next, the obtained laminated sheet was immersed in a 38 mass % ferric chloride aqueous solution (manufactured by Sunhayato Co., Ltd., etching solution H-200A) for 30 minutes to remove the conductor layer, washed with pure water, and dried to form a plate-shaped composite material got

<Example 2>

The composite material was carried out in the same manner as in Example 1, except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the non-porous inorganic fine particle were added so that the mass ratio was 44:28:28 at the time of mixing in the high-speed flow mixer. got

<Example 3>

The composite material was carried out in the same manner as in Example 1 except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the non-porous inorganic fine particle were added so that the mass ratio was 44:15:41 at the time of mixing in the V-type mixer. got

<Example 4>

As the non-porous inorganic fine particles, cordierite powder (FINE type manufactured by AGC Ceramics), an average particle diameter of 25 µm, was used and mixed with polytetrafluoroethylene and surface-modified inorganic fine particle aggregates when mixed in a high-speed flow mixer. The nonporous inorganic fine particles are added so that the mass ratio is 44:30:26, and the volatile additive is added so that 50 parts by mass when the total of polytetrafluoroethylene, the inorganic fine particle aggregate and the nonporous inorganic fine particle is 100 parts by mass, A composite material was obtained in the same manner as in Example 1.

<Example 5>

The composite material was carried out in the same manner as in Example 1, except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the nonporous inorganic fine particle were added so that the mass ratio was 38:28:34 at the time of mixing in the high-speed flow mixer. got

<Example 6>

The composite material was carried out in the same manner as in Example 1, except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the non-porous inorganic fine particle were added so that the mass ratio was 34:28:38 during mixing in a high-speed flow mixer. got

<Example 7>

The composite material was carried out in the same manner as in Example 1, except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the non-porous inorganic fine particle were added in a mass ratio of 30:28:42 during mixing in a high-speed flow mixer. got

<Example 8>

The composite material was carried out in the same manner as in Example 1, except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the nonporous inorganic fine particle were added in a mass ratio of 26:28:46 during mixing in a high-speed flow mixer. got

<Comparative Example 1>

The composite material was carried out in the same manner as in Example 1, except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the nonporous inorganic fine particle were added in a mass ratio of 60:40:0 during mixing in a high-speed flow mixer. got

<Comparative Example 2>

When mixing in a high-speed flow mixer, polytetrafluoroethylene, surface-modified inorganic fine particle aggregate and nonporous inorganic fine particle are added in a mass ratio of 40:60:0, and a volatile additive is added to polytetrafluoroethylene and inorganic fine particle aggregate. A composite material was obtained in the same manner as in Example 1, except that 100 parts by mass was added when the total of the and non-porous inorganic fine particles was 100 parts by mass.

<Comparative Example 3>

When mixing in a high-speed flow mixer, polytetrafluoroethylene, surface-modified inorganic fine particle aggregate and nonporous inorganic fine particle are added so that the mass ratio is 20:80:0, and a volatile additive is added to polytetrafluoroethylene and inorganic fine particle aggregate. A composite material was obtained in the same manner as in Example 1, except that 150 parts by mass was added when the total of the porous inorganic fine particles was 100 parts by mass.

<Comparative Example 4>

When mixing in a high-speed flow mixer, polytetrafluoroethylene, surface-modified inorganic fine particle aggregate and nonporous inorganic fine particle are added so that the mass ratio is 60:0:40, and a volatile additive is added to polytetrafluoroethylene and inorganic fine particle aggregate. A composite material was obtained in the same manner as in Example 1, except that 45 parts by mass was added when the total of the and non-porous inorganic fine particles was 100 parts by mass.

<Comparative Example 5>

The composite material was carried out in the same manner as in Comparative Example 4 except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the nonporous inorganic fine particle were added in a mass ratio of 40:0:60 during mixing in a high-speed flow mixer. got

<Comparative Example 6>

The composite material was carried out in the same manner as in Comparative Example 4 except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the non-porous inorganic fine particle were added in a mass ratio of 20:0:80 during mixing in a high-speed flow mixer. got

<Comparative Example 7>

The composite material was carried out in the same manner as in Example 1, except that polytetrafluoroethylene, the surface-modified inorganic fine particle aggregate and the non-porous inorganic fine particle were added in a mass ratio of 44:50:6 during mixing in a high-speed flow mixer. got

<Comparative Example 8>

As the non-porous inorganic fine particles, cordierite powder (FINE type manufactured by AGC Ceramics), an average particle diameter of 25 µm, was used and mixed with polytetrafluoroethylene and surface-modified inorganic fine particle aggregates when mixed in a high-speed flow mixer. The nonporous inorganic fine particles are added so that the mass ratio is 44:0:56, and the volatile additive is added so that 30 parts by mass when the total of the polytetrafluoroethylene, the inorganic fine particle aggregate and the nonporous inorganic fine particle is 100 parts by mass, A composite material was obtained in the same manner as in Example 1.

<Comparative Example 9>

When mixing in a high-speed flow mixer, polytetrafluoroethylene, surface-modified inorganic fine particle aggregate and non-porous inorganic fine particle are added in a mass ratio of 70:30:0, and a volatile additive is added to polytetrafluoroethylene and inorganic fine particle aggregate. A composite material was obtained in the same manner as in Example 1, except that 54 parts by mass was added when the total of the porous inorganic fine particles was 100 parts by mass.

<Comparative Example 10>

When mixing in a high-speed flow mixer, polytetrafluoroethylene, surface-modified inorganic fine particle aggregate and nonporous inorganic fine particle are added so that the mass ratio is 50:50:0, and a volatile additive is added to polytetrafluoroethylene and inorganic fine particle aggregate. A composite material was obtained in the same manner as in Example 1, except that 82 parts by mass was added when the total of the porous inorganic fine particles was 100 parts by mass.

<Comparative Example 11>

When mixing in a high-speed flow mixer, polytetrafluoroethylene, surface-modified inorganic fine particle aggregate and nonporous inorganic fine particle are added so that the mass ratio is 30:70:0, and a volatile additive is added to polytetrafluoroethylene and inorganic fine particle aggregate. A composite material was obtained in the same manner as in Example 1, except that 122 parts by mass was added when the total of the porous inorganic fine particles was 100 parts by mass.

For each obtained plate-shaped composite material, the porosity, peel strength, dielectric constant/dielectric loss tangent, tensile strength/tensile modulus, and coefficient of thermal expansion were measured as follows. A result is shown to Tables 1-3.

<porosity>

The volume of the composite material, the specific gravity and mass of polytetrafluoroethylene (PTFE) (compounded mass), the specific gravity and mass of the inorganic fine particle aggregate (compounded mass), the specific gravity and mass of the nonporous inorganic fine particle (compounded mass), and other fillers It was calculated by measuring the specific gravity and mass (mixed mass) of and substituting in the following formula.

[Porosity (%)]=([volume of composite material]-[mass of PTFE/ specific gravity of PTFE]-[mass of inorganic fine particle aggregate/ specific gravity of inorganic fine particle aggregate]-[mass of non-porous inorganic fine particle / non-porous inorganic Specific gravity of fine particles]-[mass of other fillers/specific gravity of other fillers])/[volume of composite material]×100

<Peel strength>

For each of the composite materials of Examples 1 to 8 and Comparative Examples 1 to 11, a copper clad laminate test for printed wiring boards in conformity with Japanese Industrial Standards JIS C6481:1996 was conducted. A test piece with a length of about 100 mm was prepared in a state in which the conductor layer was laminated with a width of 10 mm, and the average value of the load when the conductor layer portion was peeled in a direction of 90° at a speed of 50 mm/min was taken as the peel strength. measured.

<Relative permittivity, dielectric loss tangent>

The measurement frequency was 10 GHz, the complex dielectric constant was measured by the cavity resonator perturbation method, and the real part (εr') was defined as the relative dielectric constant. Further, the dielectric loss tangent was obtained from the ratio (εr″/εr′) of the real part and the imaginary part (εr″).

Using a dielectric constant measurement device (“Network Analyzer N5230C” manufactured by Agilent Technologies, Inc. and “Cavity Resonator 10 GHz” manufactured by Oyo Kaihatsu, Kanto Denshi), a rectangular sample (sample size width 2 mm × length 70) was used from each sheet. mm) was cut out and measured.

<Tensile strength and tensile modulus>

The tensile strength (tensile breaking strength) and tensile modulus of the plate-shaped composite material were measured in accordance with the method specified in Japanese Industrial Standards JIS K7161. More specifically, a tabletop precision universal testing machine Autograph AGS-X (manufactured by Shimadzu Corporation) was used as a tensile testing machine, and a measurement temperature of 25° C., a tensile speed of 100 mm/min, and an initial distance between grippers of 10 mm were measured. Under the condition, a tensile test was performed in the longitudinal direction (MD direction) of a specimen of dumbbell type No. 1 or dumbbell type No. 2 (parallel width of 10 mm). Then, the maximum tensile force recorded until the test piece is cut is obtained, and the value obtained by dividing this by the cross-sectional area of the test piece is taken as the tensile strength (unit: MPa). The tensile modulus (unit: GPa) was used as the slope of the stress/strain curve to be used.

<Coefficient of thermal expansion>

The average coefficient of thermal expansion of -50°C to 200°C was employed as the coefficient of thermal expansion, and was calculated using the TMA (Thermal Mechanical Analysis) method.

Using a thermomechanical analyzer (manufactured by BRUKER AXS, "TMA4000SA"), a composite material having a width of 4 mm and a length of 20 mm was fixed in the longitudinal direction, and a load of 2 g was applied. The residual stress of the material was removed by heating from room temperature to 200°C at a temperature increase rate of 10°C/min and holding for 30 minutes. Then, after cooling to -50 degreeC at 10 degreeC/min, hold|maintaining for 15 minutes, it heated up to 200 degreeC at 2 degreeC/min. The average coefficient of thermal expansion of -50 degreeC - 200 degreeC in the temperature rising process of the 2nd time was made into the coefficient of thermal expansion.

Fig. 2 shows graphs showing the relationship between the total filler content and dielectric loss tangent of the composite materials of Examples 5 to 8, Comparative Examples 2 to 3, and 10 to 11, Examples 5 to 8, Comparative Examples 2 to 3, and 9 to 11 3 is a graph showing the relationship between the total filler content of the composite material and the coefficient of thermal expansion. From the graph of FIG. 2, if the filler is an agglomerate of porous inorganic fine particles such as fumed silica alone, the dielectric loss tangent increases with an increase in the content of the filler, and by blending inorganic fine particles such as fused silica, it can be significantly suppressed it is clear that there is It is also clear from the graph of Fig. 3 that the increase in the coefficient of thermal expansion accompanying a decrease in the content of the porous inorganic fine particle aggregate can be suppressed by appropriate mixing of the non-porous inorganic fine particle. That is, the plate-shaped composite material in which the porous inorganic fine particle aggregate and the non-porous inorganic fine particle are appropriately blended can be said to be an excellent material in which various properties are harmonized.

In the said Example, although it showed about the specific form in this invention, the said Example is only a mere illustration and is not interpreted limitedly. Various modifications apparent to those skilled in the art are intended to be within the scope of the present invention.

The composite material according to one aspect of the present invention can be used as a circuit board for mobile phones and computers, and as a board for a microstrip patch antenna for millimeter wave radar, and the like.

Claims (2)

As a plate-shaped composite material comprising a fluorine-based resin and a filler,
The filler comprises a porous inorganic fine particle aggregate formed by aggregation of inorganic fine particles having an average primary particle diameter of 5 to 200 nm, and non-porous inorganic fine particles having an average primary particle diameter of 0.2 to 50 μm,
The total content of the porous inorganic fine particle aggregate and the non-porous inorganic fine particle is 20 to 90 mass% of the composite material, and the content of the non-porous inorganic fine particle relative to the total content of the porous inorganic fine particle aggregate and the non-porous inorganic fine particle A mass ratio (content of the non-porous inorganic fine particles/(content of the porous inorganic fine particle aggregate + the content of the non-porous inorganic fine particle)) is 0.15 to 0.90. The plate-shaped composite material according to claim 1, wherein the porosity is 15% by volume or more.

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