CN114729198B

CN114729198B - Powder composition, film, and method for producing film

Info

Publication number: CN114729198B
Application number: CN202080078282.0A
Authority: CN
Inventors: 光永敦美; 尾泽纪生; 佐藤崇
Original assignee: Asahi Glass Co Ltd
Current assignee: AGC Inc
Priority date: 2019-11-11
Filing date: 2020-11-06
Publication date: 2023-07-04
Anticipated expiration: 2040-11-06
Also published as: JPWO2021095656A1; KR20220101067A; CN114729198A; WO2021095656A1; TW202124564A

Abstract

The invention provides a powder composition suitable for melt extrusion molding into a film excellent in dielectric properties and having adhesion, processability and low linear expansion, and a film suitable for a printed substrate material. A powder composition comprising a powder of a tetrafluoroethylene polymer containing units based on perfluoro (alkyl vinyl ether) or units based on hexafluoropropylene, a powder of an inorganic filler having a Mohs hardness of 3 to 9, and a powder of a thermoplastic aromatic polymer, which comprises these components and has at least a film having a sea-island structure composed of a sea phase comprising an aromatic polymer and an island phase comprising the tetrafluoroethylene polymer.

Description

Powder composition, film, and method for producing film

Technical Field

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

Background

In recent years, in the field of information communication, a printed circuit board used has been required to have a higher density from the viewpoints of higher frequency and miniaturization of signals.

As an insulator material in the printed board, a film formed by impregnating a glass cloth with a thermosetting resin or a film formed by an aromatic polymer such as polyimide or a liquid crystalline aromatic polymer is used.

In contrast, tetrafluoroethylene polymers having electric characteristics superior to those of aromatic polymers have been attracting attention, and powder compositions obtained by blending two kinds of powders and molded articles obtained therefrom have been proposed (see patent documents 1 to 4).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2002-265729

Patent document 2: japanese patent laid-open publication No. 2003-171538

Patent document 3: japanese patent laid-open publication No. 2003-200534

Patent document 4: japanese patent laid-open publication No. 2019-065061

Disclosure of Invention

Technical problem to be solved by the invention

Tetrafluoroethylene polymer has low surface tension, and its powder has extremely low affinity with aromatic polymer. Therefore, a molded article formed from a powder composition obtained by blending two kinds of powders has not only physical shape properties such as mechanical strength but also processability due to layer separation or the like, and it is difficult to sufficiently provide physical properties of two kinds of polymers. The present inventors have found that, when other fillers are further blended in the powder composition, such tendency tends to be remarkable, and thus it is difficult to exert the effect by blending other fillers.

The purpose of the present invention is to provide a powder composition suitable for forming a molded article having physical properties such as mechanical strength and the like and having physical properties such as 3, a film having physical properties such as 3, and a method for producing the same, each of which comprises a predetermined tetrafluoroethylene polymer, an aromatic polymer, and a filler.

Technical proposal adopted for solving the technical problems

The present invention has the following technical matters.

[1] A powder composition comprising: a tetrafluoroethylene polymer powder containing a perfluoro (alkyl vinyl ether) unit or hexafluoropropylene unit, an inorganic filler powder having a Mohs hardness of 3 to 9, and a thermoplastic aromatic polymer powder.

[2] The powder composition according to [1], wherein the tetrafluoroethylene polymer is a polymer having an oxygen-containing polar group, which contains a tetrafluoroethylene-based unit and a perfluoro (alkyl vinyl ether) -based unit.

[3] The powder composition according to [1] or [2], wherein the inorganic filler is a filler containing silica.

[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 an average particle diameter of the tetrafluoroethylene polymer powder is larger than an average particle diameter of the inorganic filler.

[7] The powder composition according to any one of [1] to [6], wherein the content of the aromatic polymer is larger than the content of the tetrafluoroethylene polymer.

[8] The powder composition according to any one of [1] to [7], wherein a ratio of the content of the inorganic filler to the content of the tetrafluoroethylene polymer is 0.2 to 0.6.

[9] The powder composition according to any one of [1] to [8], wherein the content of the tetrafluoroethylene polymer, the content of the inorganic filler, and the content of the aromatic polymer are 10 to 40 mass%, 5 to 40 mass%, and 20 to 85 mass% in this order.

[10] The powder composition according to any one of [1] to [9], which is used for melt extrusion molding.

[11] A method for producing a film by melt-extruding the powder composition of any one of [1] to [10] to obtain a film.

[12] A film, comprising: a tetrafluoroethylene polymer containing a perfluoro (alkyl vinyl ether) -based unit or a hexafluoropropylene-based unit, an inorganic filler having a mohs hardness of 3 to 9, and a thermoplastic aromatic polymer, said film having at least a sea-island structure composed of a sea phase containing said aromatic polymer and an island phase containing said tetrafluoroethylene polymer.

[13] The membrane of [12], wherein the amount of the tetrafluoroethylene polymer distributed in the surface region in the thickness direction of the membrane is higher than the amount of the tetrafluoroethylene polymer distributed in the central region in the thickness direction of the membrane.

[14] The film of [12] or [13], wherein the amount of distribution of the inorganic filler in the central region in the thickness direction of the film is higher than the amount of distribution 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. Mu.m.

Effects of the invention

According to the powder composition of the present invention, a molded article such as a film having not only physical properties such as mechanical strength but also physical properties such as 3 properties, which are high, can be obtained, wherein the molded article comprises a predetermined tetrafluoroethylene polymer powder, an aromatic polymer powder, and a filler powder, respectively.

Detailed Description

The following terms have the following meanings.

The "average particle diameter" is a cumulative 50% diameter based on the volume of the object obtained by the laser diffraction/scattering method.

"melting temperature (melting point)" refers to a temperature corresponding to the maximum value of a melting peak obtained by analyzing a polymer by a Differential Scanning Calorimeter (DSC) method.

The "glass transition temperature" is a value determined by analyzing a polymer by a dynamic viscoelasticity measurement (DMA) method.

The term "substantially spherical inorganic filler" refers to an inorganic filler in which the proportion of spherical particles having a ratio of a short diameter to a long diameter of 0.7 or more is 95% or more when observed by a Scanning Electron Microscope (SEM).

The powder composition of the present invention (hereinafter also referred to as "the present composition") comprises: a powder of tetrafluoroethylene polymer (hereinafter also referred to as "TFE polymer") containing perfluoro (alkyl vinyl ether) (PAVE) unit (PAVE unit) or Hexafluoropropylene (HFP) unit (HFP unit), a powder of inorganic filler having a mohs hardness of 3 to 9 (hereinafter also referred to as "hard inorganic filler" as inorganic filler having the specific hardness), and a powder of thermoplastic aromatic polymer (hereinafter also referred to as "TAr polymer").

When the composition is melt-extruded, a molded article such as a film having a balance between the physical properties of the TFE polymer (such as electrical properties such as low dielectric loss tangent), the physical properties of the TAr polymer (such as processability and optical properties), and the physical properties of the hard inorganic filler (such as low linear expansibility) can be obtained. The reason for this is not clear, but the following reasons are considered.

TFE-based polymers are also called thermoplastic and crystalline polymers, and are excellent in physical stress resistance and heat resistance, and the powder thereof has a predetermined hardness. Therefore, it is considered that, in the melt extrusion molding, the powder of TFE-based polymer in a softened state is pulverized by a hard inorganic filler to be micronized, and thus, is densely dispersed in the melted or softened TAr polymer. In addition, it is considered that, during the dispersion, the TFE-based polymer itself does not undergo deterioration (fibrillation or the like), and therefore, the affinity between any of the components is not impaired.

Accordingly, it is considered that when the present composition is melt-extruded, a molded article having a sea-island structure composed of a sea phase containing TAr polymer and a fine island phase containing TFE polymer and densely containing a hard inorganic filler is easily formed. Therefore, it is considered that the molded article obtained from the present composition is a molded article having the physical properties of 3 (TFE polymer, TAr polymer and hard inorganic filler) at a high level.

Specifically, a molded article (film or the like) obtained by melt extrusion molding the composition has physical properties such as low dielectric constant, low dielectric loss tangent, low linear expansion coefficient, adhesiveness, and moldability. Such a molded article can be advantageously used as a material or a component of a printed board. The dielectric constant of the molded article obtained from the composition is preferably 2.0 to 4.0 as measured at 10 GHz.

The TFE-based polymer of the present invention is a polymer comprising TFE units and PAVE units or HFP units, that is, a polymer comprising TFE units and PAVE units (PFA-based polymer) or a polymer comprising TFE units and HFP units (FEP-based polymer), and is more preferably a PFA-based polymer in view of more excellent physical stress resistance and heat resistance, and further, from the viewpoint of forming fine spherulites in a molded article, thereby improving adhesion.

As PAVE, CF is preferred ₂ ＝CFOCF ₃ (PMVE)、CF ₂ ＝CFOCF ₂ CF ₃ And CF (compact F) ₂ ＝CFOCF ₂ CF ₂ CF ₃ (PPVE)。

The melting temperature (melting point) of the TFE-based polymer is preferably 260 to 320℃and more preferably 285 to 320 ℃.

The glass transition temperature of the TFE-based polymer is preferably 75 to 125℃and more preferably 80 to 100 ℃.

The TFE-based polymer preferably also contains units based on other monomers.

Examples of the other monomer include olefins (ethylene, propylene, etc.), chlorotrifluoroethylene, fluoroolefins (hexafluoropropylene, fluoroalkyl ethylene, etc.), and monomers having an oxygen-containing polar group, which will be described later.

Specific examples of the fluoroalkyl ethylene 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。

The TFE-based polymer preferably has an oxygen-containing polar group. The oxygen-containing polar group may be contained in a unit contained in the TFE-based polymer or may be contained in a terminal group of the polymer main chain. The latter TFE polymer may be, for example, a TFE 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 a TFE polymer having an oxygen-containing polar group prepared by plasma treatment, ionizing radiation treatment, or radiation treatment.

The oxygen-containing polar group is preferably a hydroxyl-containing group, a carbonyl-containing group, or a phosphono-containing group, more preferably a hydroxyl-containing group or a carbonyl-containing group, and particularly preferably a carbonyl-containing group.

As the hydroxyl group-containing group, an alcoholic hydroxyl group-containing group is preferable, and-CF is more preferable ₂ CH ₂ OH、-C(CF ₃ ) ₂ OH and 1, 2-diol (-CH (OH) CH) ₂ OH)。

As the carbonyl group-containing group, preferred is a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC (O) NH) ₂ ) Anhydride residues (-C (O) OC (O) -), imide residues (-C (O) NHC (O) -, etc.), and carbonate groups (-OC (O) O-), more preferably anhydride residues.

In the case where the TFE polymer has carbonyl groups, the number of carbonyl groups in the TFE polymer is 1X 10 ⁶ The number of main chain carbon atoms is preferably 10 to 5000, more preferably 50 to 2000. In addition, the number of carbonyl groups in the TFE type polymer may be determined by polymerizationThe composition of the product or the method described in International publication No. 2020/145133.

The TFE-based polymer having an oxygen-containing polar group preferably contains a unit based on a monomer having an oxygen-containing polar group.

The monomer is preferably a monomer having a hydroxyl group or a carbonyl group, and more preferably a monomer having a carbonyl group.

As the monomer having a carbonyl group, itaconic anhydride, citraconic anhydride, 5-norbornene-2, 3-dicarboxylic anhydride (alias: nadic anhydride; hereinafter also referred to as "NAH") and maleic anhydride are preferable, and NAH is more preferable.

As a preferred specific example of the TFE-based polymer, there can be mentioned: a polymer (1) comprising TFE units, PAVE units and units based on a monomer having an oxygen-containing polar group, a polymer (2) comprising 95.0 to 98.0 mol% of TFE units and 2.0 to 5.0 mol% of PAVE units, a polymer comprising TFE units and PMVE units.

In particular, these polymers are excellent in physical stress resistance, and when the powder composition is melt-extruded, a molded article having more excellent adhesion is easily formed by forming fine spherulites.

As the polymer (1), a polymer containing TFE units, PAVE units and units based on a monomer having a hydroxyl group or a carbonyl group is preferable. The polymer (1) preferably contains 90 to 98 mol% of TFE units, 1.5 to 9.97 mol% of PAVE units, and 0.01 to 3 mol% of units based on the above monomers, respectively, based on the total units.

As a specific example of the polymer (1), there can be mentioned a polymer described in International publication No. 2018/16644.

As the polymer (2), a polymer composed of only TFE units and PAVE units is preferable.

The PAVE unit content in the polymer (2) is preferably 2.1 mol% or more, more preferably 2.2 mol% or more, based on the total monomer units.

The polymer (2) preferably does not have an oxygen-containing polar group. In addition, the polymer (2) does not have an oxygen-containing polar groupThe term "clusters" means, per 1X 10 ⁶ The number of carbon atoms constituting the main chain of the polymer is less than 500, and the polymer has oxygen-containing polar groups. 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 using a polymerization initiator, a chain transfer agent, or the like that does not generate an oxygen-containing polar group as a terminal group of a polymer chain, or may be produced by subjecting a TFE-based polymer having an oxygen-containing polar group to a fluorination treatment.

Examples of the method of the fluorination treatment include a method using fluorine gas (see, for example, japanese patent application laid-open No. 2019-194314).

At least a part of the fine particles constituting the powder of the TFE-based polymer may be fine particles further containing a component other than the TFE-based polymer, but fine particles composed of the TFE-based polymer are preferable. Examples of the component other than the TFE-based polymer include thermoplastic polymers. As the thermoplastic polymer, TAr polymer can be used.

Examples of the thermoplastic polymer other than the TAr polymer include TFE-based polymers and TAr polymers, which will be described later.

When the powder of the TFE-based polymer is a powder further 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 mass% or less, more preferably 15 mass% or less of the total polymer components. In the case where the polymer component other than the TFE-based polymer is TAr polymer, the content of the TAr polymer is preferably 20 mass% or less, more preferably 10 mass% or less of the total polymer components.

At least a part of the fine particles of the TFE-based polymer constituting the powder may be fine particles of the TFE-based polymer containing an inorganic filler.

As the material of the inorganic filler, oxides, nitrides, metal simple substances, alloys, and carbons are preferable, silica (silica), metal oxides (beryllium oxide, cerium oxide, aluminum oxide, basic aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, and the like), boron nitride, and magnesium metasilicate (talc) 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 this 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 remainder is a powder of the hard inorganic filler.

The fine particles comprising a TFE-based polymer and an inorganic filler are preferably particles having a TFE-based polymer as a core and an inorganic filler on the surface of the core. Such particles are obtained, for example, by binding (impact, coagulation, etc.) particles of TFE-based polymer with particles of inorganic filler.

When the powder of the TFE-based polymer is a powder containing fine particles of the TFE-based polymer and an inorganic filler, the TFE-based polymer is easily and uniformly dispersed in the TAr polymer during melt molding.

When at least a part of the powder of the TFE-based polymer is a powder including fine particles containing the TFE-based polymer and an inorganic filler, the amount of the inorganic filler in the powder is preferably 50 mass% or less, more preferably 40 mass% or less, relative to the powder. In the case where at least a part of the inorganic filler is a hard inorganic filler, the amount of the hard inorganic filler is preferably 40 mass% or less, more preferably 30 mass% or less, relative to the powder.

The fine particles constituting the powder of the TFE-based polymer may further 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. When the 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, relative to the powder.

The average particle diameter of the powder of the TFE polymer (that is, the average particle diameter of the fine particles constituting the powder of the TFE polymer) is preferably 0.1 to 200. Mu.m, more preferably 1 to 100. Mu.m. In this case, the pulverization of the TFE polymer powder by the hard inorganic filler is highly advanced during melt extrusion molding, and a molded article having a more dense sea-island structure is easily formed.

The hard inorganic filler of 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, more preferably 6 or more. In this case, the pulverization of the TFE polymer powder by the hard inorganic filler is easily performed at a high level during melt extrusion molding.

The hard inorganic filler may further contain a component other than an inorganic component, but is preferably composed of an inorganic component. Examples of the components other than the inorganic component include organic compounds such as organic compounds to be used for surfactants and soft inorganic compounds such as boron nitride, which will be described later.

The hard inorganic filler is preferably an inorganic filler composed of aluminum nitride, beryllium oxide (berylia), silicon dioxide (silica), cerium oxide, aluminum oxide (aluminum), magnesium oxide (magnesia), zinc oxide, or titanium oxide.

The hard inorganic filler may be composed of 2 or more inorganic components.

The hard inorganic filler preferably contains silica. The hard inorganic filler containing silica not only has high hardness, but also its interaction with TFE-based polymer is easily enhanced. Therefore, a molded article containing the inorganic filler is likely to have a more dense island structure during melt extrusion molding. In addition, its low linear expansibility is particularly easy to exhibit.

The content of silica in the hard inorganic filler is preferably 50% by mass or more, more preferably 75% by mass or more. The content of silica is preferably 100 mass% or less.

As the hard inorganic filler, beryllium oxide filler (mohs hardness: 9), magnesium oxide 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 fused silica filler or an amorphous silica filler. In this case, the molded article easily has low thermal expansibility.

At least a part of the surface of the hard inorganic filler may be subjected to surface treatment. Examples of the surface treatment agent used for such surface treatment include: polyhydric alcohols (trimethylolethane, pentaerythritol, propylene glycol, etc.), saturated fatty acids (stearic acid, lauric acid, etc.), esters thereof, alkanolamines, amines (trimethylamine, triethylamine, etc.), paraffins, silane coupling agents, silicones, polysiloxanes, oxides of metals such as aluminum, silicon, zirconium, tin, titanium, antimony, etc., hydroxides of these metals, hydrated oxides of these metals, phosphates of these metals.

As the silane coupling agent, a silane coupling agent having a functional group is preferable, and 3-aminopropyl triethoxysilane, vinyl trimethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-methacryloxypropyl triethoxysilane, and 3-isocyanatopropyl triethoxysilane are more preferable.

The average particle diameter of the powder of the hard inorganic filler (that is, the average particle diameter of the fine particles constituting the powder of the hard inorganic filler) is preferably 0.01 μm or more, more preferably 0.1 μm or more. Further, it is preferably 10 μm or less, more preferably 2 μm or less, particularly preferably 1 μm or less.

The average particle diameter of the hard inorganic filler is preferably not more than the average particle diameter of the powder of the TFE-based polymer.

When the average particle diameter of the powder of the hard inorganic filler is within this range, the powder of the TFE-based polymer produced by the melt extrusion molding is highly pulverized, and a molded article having a more dense sea-island structure is easily formed.

Specifically, a combination of a powder of a hard inorganic filler having an average particle diameter of more than 0.10 μm and 1 μm or less and a powder of a TFE-based polymer having an average particle diameter of 1 μm or more and 3 μm or less is preferable.

The particles constituting the hard inorganic filler are preferably substantially spherical in shape. The ratio of the short diameter to the long diameter of the spherical particles, which is 95% or more of the hard inorganic filler having a substantially spherical shape, is preferably 0.8 or more, more preferably 0.9 or more. The above ratio is preferably less than 1.

The interaction between the powder of the hard inorganic filler composed of the substantially spherical fine particles and the components during melt extrusion molding is easily enhanced.

Examples of suitable powders of the hard inorganic filler include silica fillers having an average particle diameter of 1 μm or less (admafin series, etc. made by a company of a power Dou Ma, etc.), and spherical fused silica having an average particle diameter of more than 0.10 μm and 0.5 μm or less (SFP series, etc. made by a company of a power co., a power co.).

As the TAr polymer of the present invention, aromatic polyimide, aromatic polyamideimide, aromatic polyester amide, polyphenylene ether and polyphenylene sulfide are preferable.

As the TAr polymer, a liquid crystal polymer is preferable. The liquid crystal polymer is TAr polymer which forms an anisotropic melt phase and is generally referred to as thermotropic liquid crystal polymer. Specific examples of the liquid-crystalline polymer include thermoplastic and liquid-crystalline aromatic polyesters, which are often called thermotropic liquid-crystalline polyesters, and aromatic polyester amides, which are often called thermotropic liquid-crystalline polyester amides. The liquid crystal polymer may further have an imide bond, a carbonate bond, a carbodiimide bond, an isocyanurate bond, or the like introduced thereto.

As described above, when the present composition is subjected to melt extrusion molding, a molded article in which TFE-based polymer and hard inorganic filler are highly dispersed in TAr polymer can be formed.

Therefore, when the TAr polymer is a liquid crystal polymer, anisotropy of physical properties derived from the liquid crystal polymer in the flow direction (MD direction) of the molded article, which is easily exhibited, is easily alleviated by the highly dispersed TFE polymer and hard inorganic filler. In other words, isotropy of a molded article (film or the like) obtained by melt extrusion molding of the present composition comprising a TAr polymer as a liquid crystal polymer is easily improved.

As a result, it is easy to obtain a molded article having not only physical properties (mechanical properties such as strength, elasticity, vibration absorbability, and electrical properties such as dielectric characteristics) inherent to the liquid crystal polymer but also a reduction in tensile strength and thermal expansibility due to anisotropy. In particular, a molded article such as a film excellent in dimensional stability at the time of immersing in a chemical solution or at the time of heat treatment can be easily obtained.

The anisotropic molten phase of the liquid crystal polymer can be confirmed by placing the polymer sample on a heat stage, heating the polymer sample at a temperature rise in a nitrogen 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 ℃, more preferably 270 to 350 ℃.

Specific examples of the TAr polymer which is a liquid crystal polymer include: "LaPEROS" made by Baozhen Plastic Co., ltd., lapekine, a synthetic resin material, and a synthetic resin material "VECTRA (Lawsonia)", made by Sesamias, inc., incorporated, and its preparation method "UENOLCP" manufactured by Sumitomo chemical Co., ltd., and "SUMIKA SUPER" manufactured by Sumitomo chemical Co., ltd., "XYDAR" made by solvAY SPECIAL TY Polymers, inc., and "Xydar" made by JX Nigri energy Co., ltd. (J X, , dan, inc.), and "Sciberras" made by Torile, inc., respectively.

The powder of TAr polymer is composed of fine particles containing TAr polymer in a proportion of 50 mass% or more, preferably composed of fine particles containing TAr polymer in a proportion of 60 to 100 mass%. The fine particles constituting the powder may be fine particles further containing a component other than TAr polymer. Examples of the component (a) 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, ultraviolet absorbers, lubricants, and silane coupling agents. The thermoplastic polymer other than TAr polymer may be a TFE-based polymer, and the non-fibrous inorganic filler may be a hard inorganic filler.

As the component other than TAr polymer, fibrous fillers such as glass fibers, carbon fibers (PAN-based carbon fibers, pitch-based carbon fibers), organic synthetic fibers (aramid fibers and the like), metal fibers (stainless steel fibers, aluminum fibers and the like), inorganic fibers (silicon carbide fibers, potassium titanate fibers, aluminum oxide fibers and the like), natural mineral fibers (wollastonite, asbestos and the like) and the like are preferable.

When the fine powder particles of the TAr 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 fine powder particles of the TAr polymer further contain a thermoplastic polymer other than the TAr polymer, the content of the thermoplastic polymer in the powder is preferably 40 mass% or less, more preferably 20 mass% or less of the total polymer components. However, when the thermoplastic polymer is a TFE-based polymer, the amount of the thermoplastic polymer is preferably 20 mass% or less, more preferably 10 mass% or less of the total polymer components.

When the fine powder particles of the TAr polymer further contain an additive other than the above-described one, such as a non-fibrous inorganic filler, the content of the additive in the powder is preferably 30 mass% or less, more preferably 15 mass% or less. However, when the additive is a hard inorganic filler, the amount of the hard inorganic filler is preferably 20 mass% or less, more preferably 10 mass% or less, relative to the powder.

The average particle diameter of the powder of the TAr polymer (i.e., the average particle diameter of the fine particles constituting the powder of the TAr polymer) is preferably 0.1 to 200. Mu.m, more preferably 1 to 100. Mu.m. In this case, the TFE polymer and the hard inorganic filler are dispersed in the TAr polymer during melt extrusion molding, and a molded article having a dense sea-island structure is easily formed.

The composition may further contain a powder other than the powder of TFE-based polymer, the powder of hard inorganic filler, and the powder of TAr polymer.

Examples of the other powder include powders of a TFE polymer and a thermoplastic polymer other than TAr polymer, powders of a polymer other than a thermoplastic polymer, and powders of a filler other than a hard inorganic filler (such as an inorganic filler or an organic filler). The organic filler may be a fibrous organic filler composed of fibers of a polymer which is not melted during melt extrusion molding.

Specific examples of the thermoplastic polymer include polyolefin polymers (polyethylene, polypropylene, polybutene, acid-modified polyethylene, acid-modified polypropylene, acid-modified polybutene, etc.), fluorine polymers other than TFE polymers (polyvinylidene fluoride, polytetrafluoroethylene, etc.), styrene polymers (polystyrene, polyacrylonitrile styrene, polyacrylonitrile butadiene styrene, etc.), polycarbonate polymers, poly (meth) acrylic polymers, polyvinyl chloride, polyacrylate polymers, and polyurethane polymers.

Examples of the powder of the polymer other than the thermoplastic polymer include a powder composed of a cured product of a thermosetting resin, a powder of non-heat-fusible polytetrafluoroethylene, and the like.

Examples of the powder of the organic filler include powders of aramid fiber, poly (p-phenylene benzobisoxazole) fiber, polyphenylene sulfide fiber, polyester fiber, acrylic fiber, nylon fiber, polyethylene fiber, and the like.

When the present composition further contains the above-mentioned other powder, the content of the other powder in the present composition is preferably 30 mass% or less, more preferably 15 mass% or less.

The present composition is particularly preferably a composition comprising 3 kinds of powder, i.e., powder of TFE-based polymer, powder of hard inorganic filler and powder of TAr polymer. The content ratio of the 3 kinds of powder in the present composition is hereinafter referred to as the ratio in the composition composed of the 3 kinds of powder.

The content of the TFE-based polymer in the present composition is preferably 5 mass% or more, more preferably 10 mass% or more. Further, it is preferably 50% by mass or less, more preferably 40% by mass or less.

The content of the TAr polymer in the present composition is preferably 10% by mass or more, and more preferably 20% by mass or more. Further, it is preferably 90 mass% or less, more preferably 80 mass% or less.

In the present composition, the content of TAr polymer is preferably larger than the content of TFE-based polymer. That is, the present composition preferably comprises TAr polymer as the major polymer component. In this case, since the interaction with the TFE-based polymer is easily enhanced, a molded article having a more dense sea-island structure is easily formed during melt extrusion molding. In addition, its low linear expansibility is particularly easy to exhibit.

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, it is preferably 50% by mass or less, more preferably 40% by mass or less.

The ratio of the content of the hard inorganic filler to the content of the TFE-based polymer in the present composition is preferably 0.2 to 1.0, more preferably 0.2 to 0.6. In this case, the powder of the TFE-based polymer is highly pulverized during melt extrusion molding, and a molded article having a highly dispersed hard inorganic filler is easily obtained. Further, the molded article is likely to have physical properties of 3.

The content of each of the TFE-based polymer, TAr polymer, and hard inorganic filler in the present composition is preferably 10 to 40 mass%, 5 to 40 mass%, and 20 to 85 mass% in this order.

The present compositions are preferably manufactured by dry blending the individual ingredients. For dry blending, a mixing device such as a belladonna, a henschel mixer, a hopper, a banbury mixer, a roll, and Brabender (Brabender) can be used.

The present composition is preferably used for melt extrusion molding, preferably by melt extrusion molding into a film.

The melt extrusion molding is preferably performed by a method using a T-die, and more preferably by a method in which the present composition fed from a hopper is melt kneaded in an extruder (uniaxial screw or biaxial screw) and extruded by a T-die provided at the front end of the extruder to form a film.

The film obtained by melt extrusion molding is preferably further subjected to stretching treatment. Thereby, a more isotropic film can be obtained. The stretching treatment refers to a treatment of softening the film at a temperature of its melting point or lower and stretching in 1 direction (uniaxial: MD direction) or 2 directions (biaxial: MD direction and TD direction).

The stretching treatment is more preferably a biaxial stretching treatment from the viewpoint of obtaining an isotropic film.

The stretching method may, for example, be a inflation method or a plane expansion method (flat method). The rolling method may be any method of simultaneous biaxial stretching or sequential biaxial stretching.

When a film is produced by melt extrusion molding, the obtained film may be further subjected to lamination treatment, stretching treatment, cooling treatment, and peeling treatment.

The lamination process is a process of laminating a release film on both surfaces or one surface of the obtained film to form a laminate.

Examples of the lamination method include a thermocompression bonding method and a surface treatment method, and in this case, a thermocompression bonding roller, a thermocompression bonding apparatus, and a laminator (roller) may be used.

For example, when a thermocompression bonding roller is used, the obtained film and the release film may be overlapped and thermocompression bonded by the thermocompression bonding roller.

When the hot press apparatus is used, the obtained film and the release film are overlapped on a bottom plate of the hot press apparatus, and then the film and the release film are thermally press-bonded and cooled.

Further, the present composition in a molten state extruded from a T-die can be supplied to a gap between two release films by using a pair of thermocompression bonding rollers, and a laminate can be formed by using the gap portion of the thermocompression bonding rollers.

When the laminate is formed, a multilayer body in which a film formed from the composition and a release film are formed into respective layers can be formed by a coextrusion method using a multilayer die.

Examples of the material of the release film include polyethylene, polypropylene, polyether ether ketone, polyether sulfone, polyimide, polyether imide, polyacrylate, polycarbonate, polystyrene, polyvinyl chloride, polyester, polyamide imide, thermoplastic polyimide, polyphenylene sulfide, polytetrafluoroethylene, a copolymer of tetrafluoroethylene and hexafluoropropylene, a copolymer of polytetrafluoroethylene and ethylene, polyvinyl fluoride, polyvinylidene fluoride, and polytrifluoroethylene.

The thickness of the release film is preferably 10 to 200. Mu.m, more preferably 20 to 100. Mu.m.

The stretching treatment is a treatment for obtaining a stretched product by stretching the laminate while softening the release film layer of the laminate obtained in the lamination treatment. The stretching treatment may also be performed continuously.

The cooling treatment is a treatment of cooling the stretched product obtained by the stretching treatment. The cooling may be natural cooling, or may be a cooling roll or the like.

The peeling treatment is a treatment of peeling the release film from the cooled stretched product. The peeling treatment is performed by a 90 ° peeling method or a 180 ° peeling method.

By the above-described series of treatments, a film with a further suppressed thermal expansion coefficient can be obtained from the present composition.

In the film formation, blow molding may be used.

In blow molding, since the melt kneaded product of the present composition extruded from the annular die (circular die, annular die) is stretched in 2 directions (MD direction and TD direction), isotropy of the film is easily improved. In blow molding, since the melt-kneaded product is mechanically stretched in 2 directions by stretching and expansion, it is easy to form a film in which polymer molecules are oriented in 2 directions.

In this case, a film having a similar structure to the laminate may be formed by blow molding.

That is, the present composition and another thermoplastic polymer are melt extruded from an annular die and formed into a laminate by blow molding.

Examples of the laminate that can be formed at this time include: a 2-layer laminate (type 1) composed of 1 film layer of the present composition and 1 release film layer, a 3-layer laminate (type 2) composed of 2 release film layers with 1 film layer of the present composition interposed therebetween, and a 3-layer laminate (type 3) composed of 2 film layers composed of the present composition with 1 release film layer interposed therebetween, preferably a type 1 laminate or a type 3 laminate.

In these laminates, the thickness of the film layer formed from the present composition is preferably 3 to 150. Mu.m. The thickness of the release film layer is preferably not less than the thickness of the film layer and not more than 2 times the thickness of the film layer.

By the above-described series of treatments, a film having a further suppressed thermal expansion coefficient can also be obtained from the present composition.

The film of the present invention (hereinafter also referred to as "the present film") comprises a TFE-based polymer, an inorganic filler having a mohs hardness of 3 to 9, and a TAr polymer, and has a sea-island structure composed of a sea phase comprising TAr polymer and an island phase comprising TFE-based polymer.

The definition of TFE-based polymer, hard inorganic filler and TAr polymer in the present film each includes the same preferred ranges as those in the present composition.

The TFE polymer, the hard inorganic filler and the TAr polymer in the film can be uniformly distributed or concentrated.

The TFE-based polymer distribution amount in the surface region in the thickness direction of the present film is preferably higher than the TFE-based polymer distribution amount in the central region in the thickness direction of the film. In this case, the film tends to exhibit significantly physical properties (particularly, dielectric properties such as low dielectric loss tangent and adhesiveness) due to the TFE polymer.

The amount of the hard inorganic filler distributed in the central region in the thickness direction of the present film is preferably higher than the amount of the hard inorganic filler distributed in the surface region in the thickness direction of the film. In this case, physical properties (particularly, low linear expansibility and the like) due to the hard inorganic filler in the present film are easily remarkably exhibited.

The thickness of the film is preferably 5 to 1000. Mu.m, more preferably 10 to 200. Mu.m.

The present film is preferably produced by melt extrusion molding the present composition. In this case, it is easy to produce films of any of the above-mentioned various forms without impairing the mechanical strength, bendability, and other processability.

As a method for producing the present film, a T die coating method is preferably used, and specifically, the present composition after melt-kneading is preferably extruded from a T die in a molten state and is brought into contact with a cooling roll to form a film. The present composition is preferably heated and held by a non-contact heating unit before contacting with the cooling roll.

The present composition cooled by the cooling roll is preferably formed into a film shape while being transported by a transport roll and then wound by a winding roll to form a long film.

The film is preferably a metal-clad laminate by forming a metal layer on the surface thereof. Examples of the metal include: copper, nickel, aluminum, silver, gold, tin, and the like, and alloys of these metals (stainless steel, and the like).

Examples of the metal-clad laminate include: a single-sided metal-clad laminate having a metal layer and a film in this order, and a double-sided metal-clad laminate having a metal layer, a film layer and a metal layer in this order. These metal-clad laminates may further have other layers (prepreg layers, glass member layers, ceramic member layers, and other resin film layers).

As a method for forming a metal layer on the surface of the present film, there can be mentioned: a method of attaching a metal foil to the surface of the present film by a lamination method or a thermocompression method, a method of forming a metal layer on the surface of the present film by a sputtering method or an evaporation method, a method of forming a metal layer on the surface of the present film by an electroplating method (including electroless plating and electrolytic plating after electroless plating), a method of forming a metal layer on the surface of the present film by a printing method (screen printing method, inkjet method, ion plating method) using a metal conductive ink.

Further, as the metal foil, a copper foil such as a rolled copper foil or an electrolytic copper foil is preferable.

In order to further improve the adhesion with the metal layer, the surface of the present film may be subjected to surface treatment. As the surface treatment, there can be exemplified: plasma treatment, corona treatment, flame treatment, ITRO treatment.

The metal-clad laminate can be used as a material or a component such as a printed board, a high heat radiation board, or an antenna board.

For example, if the metal layer of the metal-clad laminate is etched to form a pattern circuit, a printed board can be obtained. In this case, after forming the pattern circuit, an interlayer insulating film may be formed on the pattern circuit, and then the pattern circuit may be formed on the interlayer insulating film.

In addition, a solder resist may be laminated on the pattern circuit, or a coating film may be laminated. The coating film is generally composed of a base film and an adhesive layer formed on the surface thereof, and one surface of the adhesive layer is attached to a printed board. As the base film of the coating film, the present film can be used. Further, an interlayer insulating film (adhesive layer) using the film may be formed on the pattern circuit, and a polyimide film may be laminated as a coating film.

Examples

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

The raw materials used are as follows.

1. Preparation of the ingredients

PFA-based powder 1: from a composition comprising 98.0 mol%, 0.1 mol%, 1.9 mol% TFE unit, NAH unit and PPVE unit in this order and every 1X 10 ⁶ Powder (average particle diameter: 2.0 μm) of a PFA polymer having 1000 carbonyl groups in its main chain carbon atoms (melting temperature: 300 ℃ C.)

PFA-based powder 2: consisting of TFE units and PPVE units and each 1X 10 ⁶ Powder (average particle diameter: 2.4 μm) of PFA polymer having 40 carbonyl groups in its main chain carbon atoms (melting temperature: 305 ℃ C.)

Aromatic powder 1: powder of liquid Crystal Polymer comprising 30% by mass of glass fiber which is aromatic Polymer (melting temperature: 320 ℃ C.; UENO LCP 6030G manufactured by Kogyo Co., ltd.)

Inorganic filler 1: a silica filler (average particle diameter: 0.5 μm; admafin SO-C2 manufactured by Yakeama technology Co., ltd.) having a substantially spherical shape and a Mohs hardness of 7

Inorganic filler 2: approximately spherical silica filler (average particle diameter: 5 μm) having Mohs hardness of 7

Inorganic filler 3: talc filler having Mohs hardness of 1 (average particle diameter: 0.7 μm)

Evaluation of dimensional stability of film according to JIS C6481: 1996.

A square sample of 30cm square having 2 sides in the flow direction and 2 sides in the width direction was cut out from one end in the width direction of the obtained film.

A line segment 25cm long was drawn on a diagonal line (45 ° direction at an angle of 45 ° to the flow direction, and 135 ° direction orthogonal to the 45 ° direction) of the sample surface, and punched holes centered on both ends of each line segment were formed.

The sample was immersed in an aqueous solution of ferric chloride, and the distance between the 2 punching centers before and after immersion was measured to determine the elongation and contraction of the film in the oblique direction during etching.

The sample was heated at 150℃for 30 minutes and then cooled to 25℃to measure the distance between the centers of 2 punched holes before and after the heat treatment, and the elongation and contraction of the film in the oblique direction during the heat treatment were determined.

2. Powder composition and film production example

Example 1

PFA-based powder 1 (20 parts by mass), aromatic-based powder 1 (100 parts by mass) and hard inorganic filler 1 (15 parts by mass) were dry-blended to prepare powder composition 1. The powder composition 1 was fed into a biaxial extruder (KZW 15TW-45MG made by TECHNOVEL Co., ltd.) (screw speed: 200rpm, resin temperature: 370 ℃ C.) and was discharged from a T-die provided at the tip thereof at 2.0kg/hr to form a flat film 1 (thickness: 100 μm).

Film 1 exhibits high adhesion to copper foil, has a dielectric constant of 2.9, and is excellent in dielectric characteristics. Further, the film 1 has an elongation percentage (absolute value) in the oblique direction at the time of etching and an elongation percentage (absolute value) in the oblique direction at the time of heat treatment of less than 0.1%, and the film 1 is excellent in dimensional stability.

Examples 2 to 4

Films 2 to 4 were obtained in the same manner as film 1, except that the kinds and amounts of the respective powders and inorganic fillers were changed as shown in table 1 below.

3. Evaluation

3-1 evaluation of dimensional Heat stability

The dimensional change rate of each film was measured as follows, and evaluated according to the following criteria. Further, evaluation of dimensional stability of the film was performed in accordance with JIS C6481: 1996.

Square samples of 30cm square were cut from each film.

A line segment 25cm long was drawn on the surface of the sample, and punched holes were formed with both ends of the line segment as the respective centers.

The sample was heated at 150℃for 30 minutes and then cooled to 25℃to measure the distance between the centers of 2 punched holes before and after the heat treatment, and the absolute value of the elongation and contraction rate of the film at the time of the heat treatment was used as the dimensional heat change rate.

[ evaluation criterion ]

And (2) the following steps: the thermal change rate of the dimension is less than 1.5 percent

Delta: the dimensional heat change rate is 1.5-2%

X: the thermal change rate of the dimension is more than 2 percent

3-2 evaluation of adhesion

The adhesiveness of each film was measured as follows, and evaluated according to the following criteria.

Each film was placed opposite to the scale-free copper foil, and hot-pressed (temperature: 340 ℃ C., pressurizing force: 15 kN/m) to obtain a laminate having a film layer and a copper foil layer. Rectangular test pieces having a length of 100mm and a width of 10mm were cut from the laminate. The copper foil layer was peeled from the film layer from one end of the test piece in the longitudinal direction to a position of 50 mm. At the time of peeling, a tensile tester (orintec) was used to conduct peeling at a tensile rate of 50 mm/min at a position 50mm away from one end of the test piece in the longitudinal direction, and the average load was measured at a distance of 10mm to 30mm as peel strength (N/cm).

[ evaluation criterion ]

And (2) the following steps: the peel strength is 10N/cm or more.

Delta: the peel strength is 5N/cm or more and less than 10N/cm.

X: the peel strength is less than 5N/cm.

TABLE 1

Film numbering	1	2	3	4	5
						PFA-based powder	1(20)	1(30)	1(30)	2(30)	2(30)
Aromatic powder	1(100)	1(100)	1(100)	1(100)	1(100)
						Inorganic filler	1(15)	2(15)	1(15)	1(15)	3(15)
Dimensional thermal stability	○	△	○	△	×
						Adhesion to	△	△	○	△	×

The numerical value in parentheses is the content of the components in the film (unit: parts by mass)

The films 1 to 4 had a sea-island structure composed of a sea phase containing the liquid crystal polymer 1 and an island phase containing the PFA polymer 1 or 2, as a result of cutting the respective films after freezing in liquid nitrogen and observing the cut surfaces by a scanning electron microscope (FE-SEM manufactured by hitachi high tech co.). In the films 1 to 3, the PFA-based polymer in the surface region in the thickness direction of the film was distributed more than the PFA-based polymer in the central region in the thickness direction of the film.

Industrial applicability

The powder composition of the present invention and the film of the present invention can be used as a material or a component of a printed board for electronic devices (radar, network router, chassis, wireless infrastructure, sensors for automobiles, engine management sensors, etc.) that require high frequency characteristics, in particular, transmission loss in the milliwave band needs to be reduced.

Further, the entire contents of the specification, claims and abstract of Japanese patent application No. 2019-204147 filed on 11/2019 are incorporated herein by reference as if fully set forth in the specification of the present invention.

Claims

1. A powder composition comprising: a tetrafluoroethylene polymer powder containing a perfluoro (alkyl vinyl ether) unit or hexafluoropropylene unit, an inorganic filler powder having a Mohs hardness of 3 to 9, and a thermoplastic aromatic polymer powder, wherein,

the inorganic filler is silicon dioxide or boron nitride,

the aromatic polymer is polyimide, polyamide imide, polyester amide, polyphenyl ether or polyphenyl thioether,

the content of the tetrafluoroethylene polymer, the content of the inorganic filler, and the content of the aromatic polymer are 10 to 40 mass%, 5 to 40 mass%, and 20 to 85 mass% in this order,

The ratio of the content of the inorganic filler to the content of the tetrafluoroethylene polymer is 0.2 to 0.6,

the aromatic polymer is present in an amount greater than the tetrafluoroethylene polymer,

the tetrafluoroethylene polymer powder has an average particle diameter larger than that of the inorganic filler.

2. The powder composition according to claim 1, wherein the tetrafluoroethylene polymer is a polymer having an oxygen-containing polar group containing a tetrafluoroethylene-based unit and a perfluoro (alkyl vinyl ether) -based unit.

3. The powder composition according to claim 1 or 2, wherein the inorganic filler is a filler comprising silica.

4. The powder composition according to claim 1 or 2, wherein the aromatic polymer is a liquid crystal polymer.

5. The powder composition according to claim 1 or 2, which is used for melt extrusion molding.

6. A method for producing a film by melt-extruding the powder composition according to any one of claims 1 to 5.

7. A film, comprising: a tetrafluoroethylene polymer containing a perfluoro (alkyl vinyl ether) -based unit or a hexafluoropropylene-based unit, an inorganic filler having a mohs hardness of 3 to 9, and a thermoplastic aromatic polymer, wherein the inorganic filler is silica or boron nitride, the aromatic polymer is polyimide, polyamideimide, polyester, polyesteramide, polyphenylene ether or polyphenylene sulfide, the content of the tetrafluoroethylene polymer, the content of the inorganic filler, the content of the aromatic polymer are 10 to 40 mass%, 5 to 40 mass%, 20 to 85 mass%, the ratio of the content of the inorganic filler to the content of the tetrafluoroethylene polymer is 0.2 to 0.6, the content of the aromatic polymer is greater than the content of the tetrafluoroethylene polymer, the average particle diameter of the powder of the tetrafluoroethylene polymer is greater than the average particle diameter of the inorganic filler, and the film has at least a sea island structure composed of a sea phase containing the aromatic polymer and an island phase containing the tetrafluoroethylene polymer.

8. The film according to claim 7, wherein a distribution amount of the tetrafluoroethylene-based polymer in a surface region in a thickness direction of the film is higher than a distribution amount of the tetrafluoroethylene-based polymer in a central region in the thickness direction of the film.

9. The film according to claim 7 or 8, wherein a distribution amount of the inorganic filler in a central region in a thickness direction of the film is higher than a distribution amount of the inorganic filler in a surface region in the thickness direction of the film.

10. The film according to claim 7 or 8, wherein the film has a thickness of 5 to 1000 μm.