WO2021095656A1

WO2021095656A1 - Powder composition, film, and method for producing film

Info

Publication number: WO2021095656A1
Application number: PCT/JP2020/041536
Authority: WO
Inventors: 敦美山邊; 紀生尾澤; 佐藤　崇
Original assignee: Ａｇｃ株式会社
Priority date: 2019-11-11
Filing date: 2020-11-06
Publication date: 2021-05-20
Also published as: KR20220101067A; CN114729198B; JPWO2021095656A1; CN114729198A; TW202124564A

Abstract

Provided are: a powder composition suitable for forming, by melt extrusion, films having excellent dielectric characteristics and having adhesion, processability, and low linear expansion; and a film suitable for use as a material for printed wiring boards.　The powder composition comprises a powder of a tetrafluoroethylene-based polymer including a unit based on a perfluoro(alkyl vinyl ether) or a unit based on hexafluoropropylene, a powder of an inorganic filler having a Mohs hardness of 3-9, and a powder of a thermoplastic aromatic polymer. The film comprises these ingredients and at least has a sea-island structure composed of a sea phase, which includes the aromatic polymer, and an island phase, which includes the tetrafluoroethylene-based polymer.

Description

Powder composition, film, and method for producing film

The present invention relates to a predetermined powder composition, a predetermined film, and a method for producing the same.

In recent years, in the field of information and communication, from the viewpoint of increasing the frequency and downsizing of signals, there is a demand for increasing the density of printed circuit boards used therein.
As the insulator material in the printed circuit board, a film formed by impregnating a glass cloth with a thermosetting resin and a film formed from an aromatic polymer such as polyimide or a liquid crystal aromatic polymer are used.
Further, a tetrafluoroethylene-based polymer having superior electrical properties to these aromatic polymers has attracted attention, and a powder composition obtained by blending both powders and a molded product formed from the powder composition have been proposed (Patent Documents). See 1-4).

JP-A-2002-265729 Japanese Unexamined Patent Publication No. 2003-171538 Japanese Unexamined Patent Publication No. 2003-200534 JP-A-2019-065061

Tetrafluoroethylene-based polymers have low surface tension, and their powders have extremely low affinity for aromatic polymers. Therefore, it is difficult for a molded product formed from a powder composition obtained by blending both powders to sufficiently have the physical characteristics of both polymers, not to mention the shape physical characteristics such as mechanical strength and processability due to layer separation and the like. .. The present inventors have found that when the powder composition is further blended with other fillers, such a tendency tends to be remarkable, and the effect of blending the other fillers is unlikely to be exhibited.
An object of the present invention is suitable for forming a molded product containing a predetermined tetrafluoroethylene polymer, aromatic polymer and filler, which are not limited to shape physical characteristics such as mechanical strength, and which have a high degree of three-party physical characteristics. The present invention provides a powder composition, a film having a high degree of physical characteristics of the three, and a method for producing the same.

The present invention has the following aspects.
[1] Tetrafluoroethylene polymer powder containing a unit based on perfluoro (alkyl vinyl ether) or a unit based on hexafluoropropylene, a powder of an inorganic filler having a moth hardness of 3 to 9, and a thermoplastic aromatic material. A powder composition comprising a polymer powder.
[2] The powder composition of [1], wherein the tetrafluoroethylene-based polymer is a polymer having an oxygen-containing polar group, which contains a unit based on tetrafluoroethylene and a unit based on perfluoro (alkyl vinyl ether).
[3] The powder composition of [1] or [2], wherein the inorganic filler is a filler containing silicon oxide.
[4] The powder composition according to any one of [1] to [3], wherein the aromatic polymer is polyimide, polyamideimide, polyester, polyesteramide, polyphenylene ether or polyphenylene sulfide.
[5] The powder composition according to any one of [1] to [4], wherein the aromatic polymer is a liquid crystal polymer.

[6] The powder composition according to any one of [1] to [5], wherein the average particle size of the powder of the tetrafluoroethylene polymer is larger than the average particle size of the inorganic filler.
[7] The powder composition according to any one of [1] to [6], wherein the content of the aromatic polymer is higher than the content of the tetrafluoroethylene-based polymer.
[8] The powder composition according to any one of [1] to [7], wherein the ratio of the content of the inorganic filler to the content of the tetrafluoroethylene polymer is 0.2 to 0.6.
[9] The content of the tetrafluoroethylene polymer, the content of the inorganic filler, and the content of the aromatic polymer are, in this order, 10 to 40% by mass, 5 to 40% by mass, and 20 to 85% by mass. A powder composition according to any one of [1] to [8].
[10] The powder composition according to any one of [1] to [9] used for melt extrusion molding.

[11] A method for producing a film, wherein the powder composition according to any one of [1] to [10] is melt-extruded to obtain a film.
[12] A tetrafluoroethylene-based polymer containing a unit based on perfluoro (alkyl vinyl ether) or a unit based on hexafluoropropylene, an inorganic filler having a hardness of 3 to 9 and a thermoplastic aromatic polymer. A film having at least a sea-island structure composed of a sea phase containing the aromatic polymer and an island phase containing the tetrafluoroethylene-based polymer.
[13] The distribution amount of the tetrafluoroethylene-based polymer in the surface region in the thickness direction of the film is higher than the distribution amount of the tetrafluoroethylene-based polymer in the central region in the thickness direction of the film, [12]. the film.
[14] The film of [12] or [13], wherein the distribution amount of the inorganic filler in the central region in the thickness direction of the film is higher than the distribution amount of the inorganic filler in the surface region in the thickness direction of the film.
[15] The film according to any one of [12] to [14], wherein the film has a thickness of 5 to 1000 μm.

According to the powder composition of the present invention, each of the predetermined tetrafluoroethylene polymer powder, aromatic polymer powder and filler powder is contained, and the physical characteristics of the three parties are not limited to the shape physical properties such as mechanical strength. A molded product such as a film having a high degree of the above can be obtained.

The following terms have the following meanings.
The "average particle size" is the volume-based cumulative 50% diameter of the object determined by the laser diffraction / scattering method.
The "melting temperature (melting point)" is the temperature corresponding to the maximum value of the melting peak obtained by analyzing the polymer by the differential scanning calorimetry (DSC) method.
The "glass transition point" is a value measured by analyzing a polymer by a dynamic viscoelasticity measurement (DMA) method.
The "substantially spherical inorganic filler" is an inorganic particle in which the ratio of the minor axis to the major axis is 0.7 or more and the proportion of spherical particles is 95% or more when observed with a scanning electron microscope (SEM). Means a filler.

The powder composition of the present invention (hereinafter, also referred to as “the present composition”) is a unit based on perfluoro (alkyl vinyl ether) (PAVE) (PAVE unit) or a unit based on hexafluoropropylene (HFP) (HFP unit). A powder of a tetrafluoroethylene polymer (hereinafter, also referred to as "TFE polymer") containing the above, and an inorganic filler having a moth hardness of 3 to 9 (hereinafter, an inorganic filler having this specific hardness is referred to as a "hard inorganic filler". Also referred to as) powder, and a powder of a thermoplastic aromatic polymer (hereinafter, also referred to as “TAr polymer”).
When this composition is subjected to melt extrusion molding, the physical properties of the TFE polymer (electrical properties such as low dielectric adjunct), the physical properties of the TA polymer (processability, optical properties, etc.), and the physical properties of the hard inorganic filler (low) A molded product such as a film having a good balance with linear expandability and the like can be obtained. The reason is not always clear, but it can be considered as follows.

The TFE-based polymer can be said to be a thermoplastic and crystalline polymer, and is excellent in physical stress resistance and heat resistance, and the powder thereof has a predetermined hardness. Therefore, it is considered that the powder of the TFE-based polymer in the softened state is densely dispersed in the melted or softened TAr polymer while being pulverized and atomized by the hard inorganic filler during melt extrusion molding. Further, since the TFE polymer itself does not deteriorate (fibrilize or the like) during this dispersion, it is considered that the affinity between any of the components is not impaired.
As a result, when the present composition is subjected to melt extrusion molding, a molded product densely containing a hard inorganic filler having a sea-island structure composed of a sea phase containing a Tar polymer and a fine island phase containing a TFE-based polymer. Is also considered to be easily formed. Therefore, it is considered that the molded product obtained from the present composition is a molded product having a high degree of physical characteristics of the three (TFE-based polymer, TAr polymer and hard inorganic filler).
Specifically, a molded product (film, etc.) obtained by melt extrusion molding of this composition has physical properties such as low dielectric constant, low dielectric loss tangent property, low linear expansion coefficient, adhesiveness, and moldability. doing. Such a molded product can be suitably used as a material or member of a printed circuit board. The dielectric constant of the molded product obtained from the present composition measured at 10 GHz is preferably 2.0 to 4.0.

The TFE-based polymer in the present invention is a polymer containing TFE units and PAVE units or HFP units, that is, a polymer containing TFE units and PAVE units (PFA-based polymer), or a polymer containing TFE units and HFP units (a polymer containing TFE units and HFP units). It is a FEP-based polymer), and is more preferable to be a PFA-based polymer from the viewpoint of being more excellent in physical stress resistance and heat resistance and forming fine spherulites in a molded product to further enhance the adhesiveness.
As the PAVE, CF ₂ = CFOCF ₃ (PMVE), CF ₂ = CFOCF ₂ CF ₃ and CF ₂ = CFOCF ₂ CF ₂ CF ₃ (PPVE) are preferable.
The melting temperature (melting point) of the TFE polymer is preferably 260 to 320 ° C, more preferably 285 to 320 ° C.
The glass transition point of the TFE polymer is preferably 75 to 125 ° C, more preferably 80 to 100 ° C.

The TFE-based polymer preferably further has units based on other monomers.
Examples of the other monomers include olefins (ethylene, propylene, etc.), chlorotrifluoroethylene, fluoroolefins (hexafluoropropylene, fluoroalkylethylene, etc.), and monomers having an oxygen-containing polar group described later.
Specific examples of fluoroalkylethylene include CH ₂ = CH (CF ₂ ) ₂ F, CH ₂ = CH (CF ₂ ) ₄ F, CH ₂ = CF (CF ₂ ) ₂ H, CH ₂ = CF (CF ₂ ). ₄ H, and the like.

The TFE-based polymer preferably has an oxygen-containing polar group. The oxygen-containing polar group may be contained in the unit contained in the TFE-based polymer, or may be contained in the terminal group of the polymer main chain. The latter TFE-based polymer includes a TFE-based polymer having an oxygen-containing polar functional group as a terminal group derived from a polymerization initiator, a chain transfer agent, or the like, or an oxygen-containing polymer prepared by plasma treatment, ionization line treatment, or radiation treatment. Examples thereof include TFE-based polymers having a polar group.
As the oxygen-containing polar group, a hydroxyl group-containing group, a carbonyl group-containing group, and a phosphono group-containing group are preferable, a hydroxyl group-containing group and a carbonyl group-containing group are more preferable, and a carbonyl group-containing group is particularly preferable.
As the hydroxyl group-containing group, an alcoholic hydroxyl group-containing group is preferable, and -CF ₂ CH ₂ OH, -C (CF ₃ ) ₂ OH and 1,2-glycol group (-CH (OH) CH ₂ OH) are more preferable.
Examples of the carbonyl group-containing group include a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC (O) NH ₂ ), an acid anhydride residue (-C (O) OC (O)-), and the like. An imide residue (-C (O) NHC (O)-etc.) And a carbonate group (-OC (O) O-) are preferable, and an acid anhydride residue is more preferable.
When the TFE-based polymer has a carbonyl group-containing group, the number of carbonyl group-containing groups in the TFE-based polymer is preferably 10 to 5000, more preferably 50 to 2000, per ^{1 × 10 6 main chain carbon atoms.} .. The number of carbonyl group-containing groups in the TFE-based polymer can be quantified by the composition of the polymer or the method described in International Publication No. 2020/145133.

As the TFE-based polymer having an oxygen-containing polar group, it is particularly preferable to have a unit based on a monomer having an oxygen-containing polar group.
As the above-mentioned monomer, a monomer having a hydroxyl group-containing group or a carbonyl group-containing group is preferable, and a monomer having a carbonyl group-containing group is more preferable.
Examples of the monomer having a carbonyl group-containing group include itaconic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride (also known as hymic anhydride; hereinafter also referred to as “NAH”) and maleic anhydride. Is preferable, and NAH is more preferable.
Suitable specific examples of TFE-based polymers include polymers containing TFE units, PAVE units and units based on monomers with oxygen-containing polar groups (1), 95.0-98.0 mol% TFE units and 2.0. Examples include polymers consisting of ~ 5.0 mol% PAVE units (2), polymers containing TFE units and PMVE units.
These polymers are particularly excellent in physical stress resistance, and when the powder composition is subjected to melt extrusion molding, fine spherulites are formed and it is easy to form a molded product having better adhesiveness. ..

As the polymer (1), a polymer containing a TFE unit and a PAVE unit and a monomer having a hydroxyl group-containing group or a carbonyl group-containing group is preferable. As the polymer (1), the TFE unit is 90 to 98 mol%, the PAVE unit is 1.5 to 9.97 mol%, and the unit based on the above monomer is 0.01 to 3 mol%, based on all the units. Polymers containing each are preferable.
Specific examples of the polymer (1) include the polymers described in International Publication No. 2018/16644.

As the polymer (2), a polymer consisting of only TFE units and PAVE units is preferable.
The content of PAVE units in the polymer (2) is preferably 2.1 mol% or more, more preferably 2.2 mol% or more, based on all the monomer units.
The polymer (2) preferably does not have an oxygen-containing polar group. The polymer (2) does not have oxygen-containing polar groups when the number of oxygen-containing polar groups contained in the polymer is less than 500 per ^{1 × 10 6} carbon atoms constituting the polymer main chain. It means that there is. The number of oxygen-containing polar groups is preferably 100 or less, more preferably less than 50. The lower limit of the number of oxygen-containing polar groups is usually 0.

The polymer (2) may be produced by using a polymerization initiator, a chain transfer agent, or the like that does not generate an oxygen-containing polar group as the terminal group of the polymer chain, and a TFE-based polymer having an oxygen-containing polar group is fluorinated. May be manufactured.
Examples of the fluorination treatment method include a method using fluorine gas (see JP-A-2019-194314, etc.).

At least a part of the fine particles constituting the powder of the TFE-based polymer may be fine particles containing components other than the TFE-based polymer, but the fine particles made of the TFE-based polymer are preferable. Examples of the components other than the TFE-based polymer include thermoplastic polymers. The thermoplastic polymer may be a Tar polymer.
Examples of the thermoplastic polymer other than the TA polymer include TFE-based polymers and polymers other than the TA polymer, which will be described later.
When the powder of the TFE-based polymer is a powder containing a polymer component other than the TFE-based polymer, the amount of the polymer component other than the TFE-based polymer is preferably 30% by mass or less, more preferably 15% by mass or less of the total polymer component. preferable. When the polymer component other than the TFE polymer is a Tar polymer, the content of the TAr polymer is preferably 20% by mass or less, more preferably 10% by mass or less of the total polymer components.

At least a part of the fine particles constituting the powder of the TFE-based polymer may be fine particles of the TFE-based polymer containing an inorganic filler.
As the material of the inorganic filler, oxides, nitrides, simple metals, alloys and carbons are preferable, and silicon oxide (silica) and metal oxides (berylium oxide, cerium oxide, alumina, soda alumina, magnesium oxide, zinc oxide and oxidation are preferable. Titanium etc.), boron nitride, and magnesium metasilicate (steatite) are more preferable, silica and boron nitride are more preferable, and silica is particularly preferable. The inorganic filler may be a hard inorganic filler, but in that case, it is a part of the total amount of the hard inorganic filler contained in the powder composition of the present invention, and the other is a powder of the hard inorganic filler.
The fine particles containing the TFE polymer and the inorganic filler preferably have the TFE polymer as the core and the particles having the inorganic filler on the surface of the core. Such particles are obtained, for example, by coalescing (colliding, agglomerating, etc.) particles of a TFE-based polymer and particles of an inorganic filler.
When the powder of the TFE-based polymer is a powder containing fine particles containing the TFE-based polymer and the inorganic filler, the TFE-based polymer is likely to be uniformly dispersed in the TA polymer during melt molding.
When at least a part of the powder of the TFE polymer is a powder containing fine particles containing the TFE polymer and the inorganic filler, the amount of the inorganic filler in the powder is preferably 50% by mass or less with respect to the powder. , 40% by mass or less is more preferable. When at least a part of the inorganic filler is a hard inorganic filler, the amount of the hard inorganic filler is preferably 40% by mass or less, more preferably 30% by mass or less with respect to the powder.

Further, the fine particles constituting the powder of the TFE polymer contain additives such as an organic filler, an organic pigment, a metal soap, a surfactant, an ultraviolet absorber, a lubricant, and a silane coupling agent, which will be described later. May be good. When such an additive is contained, the amount of the additive in the powder is preferably 10% by mass or less, more preferably 5% by mass or less, based on the powder.

The average particle size of the powder of the TFE polymer (that is, the average particle size of the fine particles constituting the powder of the TFE polymer) is preferably 0.1 to 200 μm, more preferably 1 to 100 μm. In this case, in the melt extrusion molding, the pulverization of the powder of the TFE polymer by the hard inorganic filler progresses to a high degree, and it is easy to form a molded product having a more dense sea-island structure.

The hard inorganic filler in the present invention is an inorganic filler having a Mohs hardness of 3 to 9.
The Mohs hardness of the hard inorganic filler is preferably 5 or more, and more preferably 6 or more. In this case, in the melt extrusion molding, the pulverization of the powder of the TFE-based polymer by the hard inorganic filler is highly likely to proceed.
The hard inorganic filler may contain a component other than the inorganic component, but is preferably composed of an inorganic component. Examples of components other than the inorganic components include organic compounds such as organic substances used in surface treatment agents described later and soft inorganic compounds such as boron nitride.
As the hard inorganic filler, an inorganic filler composed of aluminum nitride, beryllium oxide (berilia), silicon oxide (silica), cerium oxide, aluminum oxide (alumina), magnesium oxide (magnesia), zinc oxide or titanium oxide is preferable.
The hard inorganic filler may consist of two or more kinds of inorganic components.

The hard inorganic filler preferably contains silicon oxide. The hard inorganic filler containing silicon oxide not only has a high hardness, but also tends to enhance the interaction with the TFE polymer. Therefore, it is easy to form a molded product having a more dense sea-island structure from the molded product containing such an inorganic filler in melt extrusion molding. In addition, its low line expansion is particularly likely to occur.
The content of silicon oxide in the hard inorganic filler is preferably 50% by mass or more, more preferably 75% by mass or more. The content of silicon oxide is preferably 100% by mass or less.
As the hard inorganic filler, berylia filler (Mohs hardness: 9), magnesia filler (Mohs hardness: 5.5) and silica filler (Mohs hardness: 7) are preferable, and silica filler is more preferable.
The silica filler is preferably a molten silica filler or an amorphous silica filler. In this case, the molded product tends to have the low thermal expansion property.

At least a part of the surface of the hard inorganic filler may be surface-treated. Examples of the surface treatment agent used for such surface treatment include polyhydric alcohols (trimethylolethane, pentaeristol, propylene glycol, etc.), saturated fatty acids (stearic acid, lauric acid, etc.), esters thereof, alkanolamines, amines (trimethylamine, etc.). Triethylamine etc.), paraffin wax, silane coupling agent, silicone, polysiloxane, and metal oxides such as aluminum, silicon, zirconium, tin, titanium, antimony, hydroxides of those metals, hydration oxidation of those metals Examples include phosphates of those metals.
As the silane coupling agent, a silane coupling agent having a functional group is preferable, and 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-Methoxyloxypropyltriethoxysilane and 3-isocyanatepropyltriethoxysilane are more preferred.

The average particle size of the hard inorganic filler powder (that is, the average particle size of the fine particles constituting the hard inorganic filler powder) is preferably 0.01 μm or more, more preferably 0.1 μm or more. Further, 10 μm or less is preferable, 2 μm or less is more preferable, and 1 μm or less is particularly preferable.
The average particle size of the hard inorganic filler is preferably equal to or less than the average particle size of the powder of the TFE polymer.
If the average particle size of the hard inorganic filler powder is within such a range, the powder of the TFE polymer is highly pulverized by the melt extrusion molding, and a molded product having a finer sea-island structure is formed. It's easy to do.
Specifically, a combination of a hard inorganic filler powder having an average particle size of more than 0.10 μm and 1 μm or less and a TFE polymer powder having an average particle size of 1 μm or more and 3 μm or less is preferable.

The shape of the fine particles constituting the hard inorganic filler is preferably substantially spherical. In the spherical particles accounting for 95% or more of the substantially spherical hard inorganic filler, the ratio of the minor axis to the major axis is preferably 0.8 or more, more preferably 0.9 or more. The above ratio is preferably less than 1.
The powder of the hard inorganic filler composed of substantially spherical fine particles tends to enhance the interaction with each component in melt extrusion molding.
Suitable specific examples of the hard inorganic filler powder include silica fillers having an average particle size of 1 μm or less (such as the “Admafine” series manufactured by Admatex), and an average particle size of more than 0.10 μm and 0.5 μm. Examples thereof include spherical fused silica (“SFP” series manufactured by Denka Co., Ltd., etc.) described below.

As the TA polymer in the present invention, aromatic polyimide, aromatic polyamideimide, aromatic polyester, aromatic polyesteramide, polyphenylene ether and polyphenylene sulfide are preferable.
As the Tar polymer, a liquid crystal polymer is preferable. The liquid crystal polymer is a Tar polymer that forms an anisotropic molten phase, and is generally called a thermotropic liquid crystal polymer. Specific examples of the liquid crystal polymer include thermoplastic and liquid crystalline aromatic polyester and aromatic polyester amide. The former is often referred to as a thermotropic liquid crystal polyester, and the latter is often referred to as a thermotropic liquid crystal polyester amide. An imide bond, a carbonate bond, a carbodiimide bond, an isocyanate bond, or the like may be further introduced into the liquid crystal polymer.

As described above, when the present composition is subjected to melt extrusion molding, the TFE polymer and the hard inorganic filler are highly dispersed in the TA polymer to form a molded product.
Therefore, the anisotropy of the physical properties derived from the liquid crystal polymer in the flow direction (MD direction) of the molded product, which is likely to occur when the Tar polymer is a liquid crystal polymer, is alleviated by the highly dispersed TFE polymer or hard inorganic filler. Easy to be done. In other words, a molded product (film or the like) obtained by melt extrusion molding from the present composition in which the Tar polymer is a liquid crystal polymer tends to be highly isotropic.
As a result, while having the physical characteristics peculiar to the liquid crystal polymer (mechanical properties such as strength, elasticity and vibration absorption, and electrical properties such as dielectric properties), the decrease in tensile strength and thermal expansion due to anisotropy is suppressed. It is easy to obtain the molded product. In particular, it is easy to obtain a molded product such as a film having excellent dimensional stability during immersion in a chemical solution or heat treatment.

The anisotropic molten phase of the liquid crystal polymer may be confirmed, for example, by placing the polymer sample on a hot stage, heating the polymer sample in a nitrogen gas atmosphere, and observing the transmitted light of the polymer sample.
The melting temperature (melting point) of the liquid crystal polymer is preferably 250 to 370 ° C, more preferably 270 to 350 ° C.
Specific examples of the TAr polymer, which is a liquid crystal polymer, include "Laperos" manufactured by Polyplastics, "Vectra" manufactured by Celanese, "UENOLCP" manufactured by Ueno Fine Chemicals Industry, and "Sumika Super LCP" manufactured by Sumitomo Chemical Co., Ltd. Examples include "XYDAR" manufactured by SOLVAY SPECIALTY POLYMERS, "Zider" manufactured by JX Nikko Nisseki Energy Co., Ltd., and "Siberus" manufactured by Toray Industries, Inc.

The powder of the Tar polymer is a powder composed of fine particles containing the Tar polymer in a proportion of 50% by mass or more, and a powder composed of fine particles containing the Tar polymer in a proportion of 60 to 100% by mass is preferable. The fine particles constituting the powder may be fine particles containing components other than the Tar polymer. Such components include thermoplastic polymers other than TAr polymers, fibrous inorganic fillers, fibrous organic fillers, non-fibrous inorganic fillers, non-fibrous organic fillers, organic pigments, metal soaps, surfactants, and ultraviolet rays. Additives such as absorbents, lubricants and silane coupling agents can be mentioned. The thermoplastic polymer other than the Tar polymer may be a TFE-based polymer, and the non-fibrous inorganic filler may be a hard inorganic filler.
Ingredients other than TA polymer include glass fiber, carbon fiber (PAN-based carbon fiber, pitch-based carbon fiber), organic synthetic fiber (aromatic polyamide fiber, etc.), metal fiber (stainless fiber, aluminum fiber, etc.), inorganic fiber. Fibrous fillers such as (silicon carbide fiber, potassium titanate fiber, alumina fiber, etc.) and natural ore-based fiber (walasnite, asbestos, etc.) are preferable.

When the powder fine particles of the TA polymer contain a fibrous filler, the content of the fibrous filler in the powder is preferably 40% by mass or less, more preferably 35% by mass or less.
When the powder fine particles of the TA polymer contain a thermoplastic polymer other than the TA polymer, the content of the thermoplastic polymer in the powder is preferably 40% by mass or less, more preferably 20% by mass or less of the total polymer components. However, when the thermoplastic polymer is a TFE-based polymer, it is preferably 20% by mass or less, more preferably 10% by mass or less of the total polymer components.
When the powder fine particles of the TAr polymer contain additives other than the above, such as a non-fibrous inorganic filler, the content of such additives in the powder is preferably 30% by mass or less, more preferably 15% by mass or less. However, when the additive is a hard inorganic filler, the amount of the hard inorganic filler is preferably 20% by mass or less, more preferably 10% by mass or less with respect to the powder.

The average particle size of the tar polymer powder (that is, the average particle size of the fine particles constituting the tar polymer powder) is preferably 0.1 to 200 μm, more preferably 1 to 100 μm. In this case, in melt extrusion molding, the TFE polymer and the hard inorganic filler are dispersed in the Tar polymer, and it is easy to form a molded product having a dense sea-island structure.

The present composition may further contain powders other than TFE-based polymer powders, hard inorganic filler powders, and TAr polymer powders.
Examples of other powders include powders of thermoplastic polymers other than TFE polymers and TAr polymers, powders of polymers other than thermoplastic polymers, and powders of fillers other than hard inorganic fillers (such as the inorganic fillers and organic fillers). , Etc. can be mentioned. Examples of the organic filler include fibrous organic fillers made of polymer fibers that do not melt in melt extrusion molding.
Specific examples of the thermoplastic polymer include polyolefin polymers (polyethylene, polypropylene, polybutylene, acid-modified polyethylene, acid-modified polypropylene, acid-modified polybutylene, etc.) and fluoropolymers other than TFE-based polymers (polyfluorovinylidene, polytetrafluoro). (Ethethylene, etc.), styrene-based polymers (polystyrene, polyacrylonitrile styrene, polyacrylonitrile butadiene styrene, etc.), polycarbonate-based polymers, poly (meth) acrylic-based polymers, polyvinyl chloride, polyarelliton-based polymers, polyurethane-based polymers.
Examples of the polymer powder other than the thermoplastic polymer include a powder made of a cured product of a thermosetting resin, a powder of non-thermomeltable polytetrafluoroethylene, and the like.
Examples of the powder of the organic filler include powders composed of aromatic polyamide fibers, polyaramid fibers, polyparaphenylene benzoxazole fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers, polyethylene fibers and the like.
When the present composition contains the above other powder, the content of the other powder in the present composition is preferably 30% by mass or less, more preferably 15% by mass or less.

The composition is particularly preferably composed of three types of powders: a TFE-based polymer powder, a hard inorganic filler powder, and a TAr polymer powder. The content ratio of the powders of these three substances in the following composition refers to the ratio in the composition composed of these three types of powders.
The content of the TFE polymer in the present composition is preferably 5% by mass or more, more preferably 10% by mass or more. Further, 50% by mass or less is preferable, and 40% by mass or less is more preferable.
The content of the Tar polymer in the present composition is preferably 10% by mass or more, more preferably 20% by mass or more. Further, 90% by mass or less is preferable, and 80% by mass or less is more preferable.
The content of the TAr polymer in the present composition is preferably higher than the content of the TFE-based polymer. That is, the present composition preferably contains a Tar polymer as a main polymer component. In this case, since the interaction with the TFE-based polymer is likely to be enhanced, it is easy to form a molded product having a finer sea-island structure in melt extrusion molding. In addition, its low line expansion is particularly likely to occur.

The content of the hard inorganic filler in the present composition is preferably 5% by mass or more, more preferably 10% by mass or more. Further, 50% by mass or less is preferable, and 40% by mass or less is more preferable.
The ratio of the content of the hard inorganic filler to the content of the TFE polymer in the present composition is preferably 0.2 to 1.0, more preferably 0.2 to 0.6. In this case, in melt extrusion molding, the powder of the TFE polymer is highly pulverized, and it is easy to obtain a molded product in which the hard inorganic filler is highly dispersed. In addition, it is easy for the molded product to have the physical characteristics of the three parties.
The contents of the TFE polymer, the Tar polymer, and the hard inorganic filler in the present composition are preferably 10 to 40% by mass, 5 to 40% by mass, and 20 to 85% by mass in this order.

The present composition is preferably produced by dry blending each component. For dry blending, a mixing device such as a tumbler, a Henschel mixer, a hopper, a Banbury mixer, a roll, or a lavender can be used.
The present composition is preferably used for melt extrusion molding, and is preferably molded into a film by melt extrusion molding.
The melt extrusion molding is preferably carried out by a method using a T-die, and the composition charged from the hopper is melt-kneaded in an extruder (uniaxial screw or biaxial screw) and installed at the tip of the extruder. It is more preferable to carry out by a method of extruding from the T-die to form a film.

The film obtained by melt extrusion is preferably further stretched. This gives a more isotropic film. The stretching treatment is a treatment in which the film is softened at a temperature equal to or lower than its melting point and stretched in one direction (1 axis: MD direction) or 2 directions (2 axes: MD direction and TD direction).
The stretching treatment is more preferably a biaxial stretching treatment from the viewpoint of obtaining an isotropic film.
Examples of the stretching method include an inflation method and a flat method. As the flat method, either simultaneous biaxial stretching or sequential biaxial stretching can be adopted.

In the production of a film by melt extrusion molding, the obtained film may be further subjected to a laminating treatment, a stretching treatment, a cooling treatment and a peeling treatment.
The laminating treatment is a treatment of laminating a release film on both sides or one side of the obtained film to form a laminated body.
Examples of the laminating method include a thermocompression bonding method and a surface treatment method, in which a thermocompression bonding roll, a thermal press device, and a laminator are used.
For example, when a thermocompression bonding roll is used, the obtained film and the release film may be laminated and passed through the thermocompression bonding roll for thermocompression bonding.
When a hot press device is used, the film obtained on the bottom plate of the hot press device and the release film may be laminated and thermocompression bonded to cool the film.

Further, using a pair of thermocompression bonding rolls, the composition in a molten state extruded from the T die is supplied to the gap between the two release films, and the laminate is formed in the gap between the thermocompression bonding rolls. Good.
When forming this laminated body, if a coextrusion method using a multilayer die is used, a multilayer body in which the film formed from the present composition and the release film are each layered can be formed.
The material of the release film is polyethylene, polypropylene, polyether ether ketone, polyether sulfone, polyimide, polyetherimide, polyarylate, polycarbonate, polystyrene, polyvinyl chloride, polyester, polyamide, polyamideimide, thermoplastic polyimide, polyphenylene sulfide. , Polytetrafluoroethylene, copolymer of tetrafluoroethylene and hexafluoropropylene, copolymer of polytetrafluoroethylene and ethylene, polyvinyl chloride, vinylidene polyfluoride, polyethylene trifluoride chloride.
The thickness of the release film is preferably 10 to 200 μm, more preferably 20 to 100 μm.

The stretching treatment is a treatment for obtaining a stretched product by stretching the laminated body while softening the release film layer of the laminated body obtained by the laminating treatment. This stretching treatment may be carried out continuously.
The cooling treatment is a treatment for cooling the stretched product obtained by the stretching treatment. Cooling may be natural cooling, or a cooling roll or the like may be used.
The peeling treatment is a treatment for peeling the peeling film from the cooled stretched product. The peeling process can be performed by a 90 ° peeling method or a 180 ° peeling method.
By such a series of treatments, a film having a more suppressed coefficient of thermal expansion can be obtained from the present composition.

Inflation molding may be used in the molding of the film.
In inflation molding, the melt-kneaded product of the present composition extruded from an annular die (round die, circular die) is stretched in two directions (MD direction and TD direction), so that the isotropic property of the film is likely to be improved. .. In insulation molding, since the melt-kneaded product is mechanically stretched in two directions by taking up and expanding, it is easy to mold a film in which polymer molecules are oriented in two directions.
Further, at this time, a film having a structure similar to that of the above-mentioned laminate may be formed by inflation molding.
That is, the composition and other thermoplastic polymers are melt-extruded from a cyclic die and inflation-molded to form a laminate.

The laminate that can be formed at this time is a two-layer laminate (type 1) composed of a film layer formed from one of the present compositions and one release film layer, and one piece between the two release film layers. A three-layer laminate in which a film layer formed from the composition is sandwiched (type 2), and a three-layer laminate in which one release film layer is sandwiched between two film layers formed from the present composition (type 2). 3) is mentioned, and a type 1 laminate or a type 3 laminate is preferable.
The thickness of the film layer formed from the present composition in these laminates is preferably 3 to 150 μm. The thickness of the release film layer is preferably at least twice the thickness of the film layer.
By such a series of treatments, a film having a more suppressed coefficient of thermal expansion can be obtained from the present composition.

The film of the present invention (hereinafter, also referred to as "the present film") contains a TFE-based polymer, an inorganic filler having a moth hardness of 3 to 9, a TAr polymer, a sea phase containing a TAr polymer, and a TFE-based polymer. It has a sea-island structure composed of an island fauna including.
The definitions of TFE-based polymers, hard inorganic fillers, and TAr polymers in the film are similar to those in the composition, including the preferred range.
In this film, the TFE-based polymer, the hard inorganic filler, and the TAr polymer may be uniformly distributed or may be unevenly distributed.

The distribution amount of the TFE-based polymer in the surface region in the thickness direction of the film is preferably higher than the distribution amount of the TFE-based polymer in the central region in the thickness direction of the film. In this case, the physical properties (particularly, the dielectric properties such as low dielectric contact and the adhesiveness) caused by the TFE polymer in this film are likely to be remarkably exhibited.
The distribution amount of the hard inorganic filler in the central region in the thickness direction of the film is preferably higher than the distribution amount of the hard inorganic filler in the surface region in the thickness direction of the film. In this case, the physical characteristics (particularly, low line expansion) caused by the hard inorganic filler in this film are likely to be remarkably exhibited.

The thickness of this film is preferably 5 to 1000 μm, more preferably 10 to 200 μm.
The film is preferably produced by melt extrusion of the composition. In this case, it is easy to manufacture films of various arbitrary embodiments described above without impairing processability such as mechanical strength and bendability.
As a method for producing the film, it is preferable to use the T die coating method. Specifically, the melt-kneaded composition is discharged from the T die in a molten state and brought into contact with a cooling roll to form a film. Is preferable. It is preferable that the melt-kneaded composition is heated and held in a non-contact heating unit before coming into contact with the cooling roll.
It is preferable that the composition cooled by the cooling roll is formed into a film while being conveyed by the conveying roller, and is wound by the take-up roll to be formed into a long film.

It is preferable that the present film has a metal layer formed on its surface to form a metal-clad laminate. Examples of the metal include various metals such as copper, nickel, aluminum, silver, gold and tin, and alloys thereof (stainless steel and the like).
Examples of such a metal-clad laminate include a single-sided metal-clad laminate having a metal layer and the present film in this order, a metal layer, and a double-sided metal-clad laminate having the present film layer and the metal layer in this order. Further, these metal-clad laminates may have further another layer (prepreg layer, glass member layer, ceramic member layer, other resin film layer).
As a method of forming a metal layer on the surface of this film, a metal foil is attached to the surface of this film by a laminating method or a thermocompression bonding method, or a metal layer is formed on the surface of this film by a sputtering method or a vapor deposition method. Method, method of forming a metal layer on the surface of this film by electroless plating or electrolytic plating after electroless plating, printing method using metal conductive ink (screen printing method, inkjet method, A method of forming a metal layer on the surface of the present film by the ion plating method) can be mentioned.
As the metal foil, a copper foil such as a rolled copper foil or an electrolytic copper foil is preferable.

The surface of the film may be surface-treated in order to further improve the adhesiveness with the metal layer. Examples of the surface treatment include plasma treatment, corona treatment, flame treatment, and itro treatment.
Such a metal-clad laminate can be used as a material or member for a printed circuit board, a high heat dissipation substrate, an antenna substrate, or the like.
For example, a printed circuit board can be obtained by etching the metal layer of the metal-clad laminate to form a pattern circuit. At this time, after forming the pattern circuit, an interlayer insulating film may be formed on the pattern circuit, and a pattern circuit may be further formed on the interlayer insulating film.
Further, a solder resist may be laminated on the pattern circuit, or a coverlay film may be laminated. The coverlay film is typically composed of a base film and an adhesive layer formed on the surface thereof, and the surface on the adhesive layer side is attached to the printed circuit board. This film may be used as the base film of the coverlay film. Further, an interlayer insulating film (adhesive layer) using this film may be formed on the pattern circuit, and a polyimide film may be laminated as a coverlay film.

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto.
The raw materials used are shown below.
1. 1. Preparation of each component PFA-based powder 1: Contains 98.0 mol%, 0.1 mol%, and 1.9 mol% of TFE units, NAH units, and PPVE units in this order, and contains a carbonyl group-containing group as the main chain carbon number. Powder (average particle size: 2.0 μm) composed of 1000 PFA-based polymers (melting temperature: 300 ° C.) per 1 × 10 ^{6 pieces}
PFA-based powder 2: A powder (average particle size) composed of a PFA-based polymer (melting temperature: 305 ° C.) having 40 ^{carbonyl group-containing groups per 1 × 10 6} main chain carbon atoms, which is composed of TFE units and PPVE units. : 2.4 μm)
Aromatic powder 1: Liquid crystal polymer powder that is an aromatic polymer containing 30% by mass of glass fiber (melting temperature: 320 ° C; manufactured by Ueno Fine Chemicals Industry, "UENO LCP 6030G")
Inorganic filler 1: Silica filler having a Mohs hardness of 7 and a substantially spherical shape (average particle size: 0.5 μm; manufactured by Admatex, “Admafine SO-C2”)
Inorganic filler 2: Silica filler having a Mohs hardness of 7 and a substantially spherical shape (average particle size: 5 μm)
Inorganic filler 3: Mohs hardness is 1, talc filler (average particle size: 0.7 μm)

The evaluation of the dimensional stability of the film was based on JIS C 6488: 1996.
From the widthwise edge of the obtained film, a 30 cm square square sample having two sides along the flow direction and two sides along the width direction was cut out.
Line segments with a length of 25 cm are drawn on the diagonal lines of the surface of this sample (the 45 ° direction in which the angle formed by the flow direction is 45 ° and the 135 ° direction orthogonal to the 45 ° direction), and each line segment is drawn. Punch holes were formed around both ends of the.
The sample was immersed in an aqueous iron chloride solution, the distance between the centers of the two punch holes before and after immersion was measured, and the expansion / contraction rate of the film in the oblique direction during etching was determined.
The sample was heat-treated at 150 ° C. for 30 minutes and then cooled to 25 ° C., and the distance between the centers of the two punch holes before and after the heat treatment was measured to determine the expansion / contraction rate of the film in the oblique direction during the heat treatment. ..

2. Production example of powder composition and film [Example 1]
A powder composition 1 was prepared by dry-blending PFA-based powder 1 (20 parts by mass), aromatic powder 1 (100 parts by mass), and hard inorganic filler 1 (15 parts by mass). The powder composition 1 was put into a twin-screw extruder (manufactured by Technobel Co., Ltd., "KZW15TW-45MG"), melt-kneaded (screw rotation speed: 200 rpm, set resin temperature: 370 ° C.), and a T-die installed at the tip thereof. To form a flat film 1 (thickness: 100 μm) by discharging at 2.0 kg / hr.
The film 1 showed high adhesiveness to the copper foil, and its dielectric constant was 2.9, which was excellent in dielectric properties. Further, the stretch ratio in the diagonal direction of the film in the etching of the film 1 and the stretch ratio (absolute value) in the diagonal direction of the film in the heat treatment are both less than 0.1%, and the film 1 has dimensional stability. It was excellent.
[Examples 2 to 4]
Films 2 to 4 were obtained in the same manner as in Film 1, except that the types and amounts of the respective powders and inorganic fillers were changed as shown in Table 1 below.

3. 3. Evaluation 3-1. Evaluation of dimensional thermal stability The dimensional change rate of each film was measured as follows and evaluated according to the following criteria. The evaluation of the dimensional stability of the film was based on JIS C 6488: 1996.
A 30 cm square square sample was cut out from each film.
A line segment having a length of 25 cm was drawn on the surface of this sample to form punch holes centered on both ends of the line segment.
After heating the sample at 150 ° C. for 30 minutes, heat treatment is performed to cool it to 25 ° C., the distance between the centers of the two punch holes before and after the heat treatment is measured, and the absolute value of the stretch ratio of the film in the heat treatment is determined by the dimensional heat. The rate of change was used.
[Evaluation criteria]
〇: Dimensional heat change rate is less than 1.5% Δ: Dimensional heat change rate is 1.5 or more and 2% or less ×: Dimensional heat change rate is more than 2%

3-2. Evaluation of Adhesiveness The adhesiveness of each film was measured as follows and evaluated according to the following criteria.
Each film and a solid copper foil were placed facing each other and heat-pressed (temperature: 340 ° C., pressing force: 15 kN / m) to obtain a laminate having a film layer and a copper foil layer. A rectangular test piece having a length of 100 mm and a width of 10 mm was cut out from this laminated body. The copper foil layer was peeled from the film layer to a position 50 mm from one end in the length direction of the test piece. When peeling, the test piece is peeled 90 degrees at a tensile speed of 50 mm / min using a tensile tester (manufactured by Orientec) with the position 50 mm from one end in the length direction as the center, and the measurement distance is 10 mm to 30 mm. The average load up to was measured and used as the peel strength (N / cm).
[Evaluation criteria]
〇: The peel strength is 10 N / cm or more.
Δ: The peel strength is 5 N / cm or more and less than 10 N / cm.
X: The peel strength is less than 5 N / cm.

As a result of freezing each film in liquid nitrogen, cutting the film, and observing the cut surface with a scanning electron microscope (FE-SEM manufactured by Hitachi High Technologies America), the films 1 to 4 are the sea containing the liquid crystal polymer 1. It had a sea-island structure composed of a phase and an island phase containing PFA-based polymer 1 or 2. Further, in the films 1 to 3, the distribution amount of the PFA-based polymer in the surface region in the film thickness direction was higher than the distribution amount of the PFA-based polymer in the central region in the film thickness direction.

The powder composition of the present invention and the film of the present invention have high frequency characteristics, particularly electronic devices (radars, network routers, backplanes, wireless infrastructures, automobile sensors, engines) that require reduction of transmission loss in the millimeter wave band. It is useful as a material or member of a printed circuit board used for (management sensor, etc.).
The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2019-204147 filed on November 11, 2019 are cited here and incorporated as disclosure of the specification of the present invention. Is.

Claims

Tetrafluoroethylene polymer powder containing a unit based on perfluoro (alkyl vinyl ether) or a unit based on hexafluoropropylene, an inorganic filler powder having a Mohs hardness of 3 to 9, and a thermoplastic aromatic polymer powder. A powder composition comprising a body.
The powder composition according to claim 1, wherein the tetrafluoroethylene-based polymer is a polymer having an oxygen-containing polar group containing a unit based on tetrafluoroethylene and a unit based on perfluoro (alkyl vinyl ether).
The powder composition according to claim 1 or 2, wherein the inorganic filler is a filler containing silicon oxide.
The powder composition according to any one of claims 1 to 3, wherein the aromatic polymer is polyimide, polyamideimide, polyester, polyesteramide, polyphenylene ether or polyphenylene sulfide.
The powder composition according to any one of claims 1 to 4, wherein the aromatic polymer is a liquid crystal polymer.
The powder composition according to any one of claims 1 to 5, wherein the average particle size of the powder of the tetrafluoroethylene polymer is larger than the average particle size of the inorganic filler.
The powder composition according to any one of claims 1 to 6, wherein the content of the aromatic polymer is higher than the content of the tetrafluoroethylene-based polymer.
The powder composition according to any one of claims 1 to 7, wherein the ratio of the content of the inorganic filler to the content of the tetrafluoroethylene polymer is 0.2 to 0.6.
Claims that the content of the tetrafluoroethylene polymer, the content of the inorganic filler, and the content of the aromatic polymer are, in this order, 10 to 40% by mass, 5 to 40% by mass, and 20 to 85% by mass. Item 2. The powder composition according to any one of Items 1 to 8.
The powder composition according to any one of claims 1 to 9, which is used for melt extrusion molding.
A method for producing a film, wherein the powder composition according to any one of claims 1 to 10 is melt-extruded to obtain a film.
The aromatic polymer contains a tetrafluoroethylene polymer containing a unit based on perfluoro (alkyl vinyl ether) or a unit based on hexafluoropropylene, an inorganic filler having a Morse hardness of 3 to 9, and a thermoplastic aromatic polymer. A film having at least a sea-island structure composed of a sea phase containing the above and an island phase containing the tetrafluoroethylene-based polymer.
The film according to claim 12, wherein the distribution amount of the tetrafluoroethylene-based polymer in the surface region in the thickness direction of the film is higher than the distribution amount of the tetrafluoroethylene-based polymer in the central region in the thickness direction of the film. ..
The film according to claim 12 or 13, wherein the distribution amount of the inorganic filler in the central region in the thickness direction of the film is higher than the distribution amount of the inorganic filler in the surface region in the thickness direction of the film.
The film according to any one of claims 12 to 14, wherein the film has a thickness of 5 to 1000 μm.