KR20220101067A - Powder composition, film, and method for producing film - Google Patents

Abstract

To provide a powder composition suitable for melt extrusion molding a film having excellent dielectric properties, adhesion, processability and low linear expansion properties, and a film suitable for a printed circuit board material.
A 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 Mohs hardness of 3 to 9, and a thermoplastic aromatic A powder composition containing polymer powder, and a film having at least a sea-island structure composed of a sea containing an aromatic polymer and an island phase containing the above-mentioned tetrafluoroethylene 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.

BACKGROUND ART In recent years, in the field of information and communication, high-density printed circuit boards used therein are required from the viewpoints of high-frequency and downsizing of signals.

As an insulator material in a printed circuit board, the film shape|molded by making glass cloth impregnate a thermosetting resin, and the film shape|molded with aromatic polymers, such as polyimide and a liquid crystalline aromatic polymer, are used.

In addition, tetrafluoroethylene-based polymers superior in electrical properties to these aromatic polymers are attracting attention, and a powder composition obtained by blending both powders and a molded article formed therefrom have been proposed (see Patent Documents 1 to 4).

Japanese Laid-Open Patent Publication No. 2002-265729 Japanese Laid-Open Patent Publication No. 2003-171538 Japanese Laid-Open Patent Publication No. 2003-200534 Japanese Laid-Open Patent Publication No. 2019-065061

The tetrafluoroethylene polymer has a low surface tension, and the powder has very low affinity for the aromatic polymer. For this reason, it is difficult for a molded article formed of a powder composition blending both powders to have sufficient physical properties of both polymers, as well as shape physical properties such as mechanical strength and workability, due to layer separation or the like. When another filler is further blended with a powder composition, this tendency tends to become remarkable, and the present inventors know the point difficult to express the effect by the blend of another filler.

An object of the present invention is a powder composition suitable for the formation of a molded article, each containing a predetermined tetrafluoroethylene-based polymer, an aromatic polymer, and a filler, not limited to shape properties such as mechanical strength, and having high three-dimensional properties , a film highly equipped with three properties of physical properties, and a method for manufacturing the same.

The present invention has the following aspects.

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

[2] The powder of [1], wherein the tetrafluoroethylene-based polymer is a polymer having an oxygen-containing polar group including a tetrafluoroethylene-based unit and a perfluoro(alkylvinyl ether)-based unit. composition.

[3] The powder composition according to [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 diameter of the tetrafluoroethylene-based polymer powder is larger than the 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 greater than the content of the tetrafluoroethylene-based 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-based polymer is 0.2 to 0.6.

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

[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, wherein the powder composition according to any one of [1] to [10] is melt-extruded to obtain a film.

[12] A tetrafluoroethylene polymer comprising a unit based on perfluoro (alkylvinyl ether) or a unit based on hexafluoropropylene, an inorganic filler having a Mohs hardness of 3 to 9, and a thermoplastic aromatic polymer A film comprising 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] ] of 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 contains a predetermined tetrafluoroethylene-based polymer powder, an aromatic polymer powder, and a filler powder, and is not limited to shape properties such as mechanical strength, but has high three-dimensional properties Molded articles, such as a film to be used, are obtained.

The following terms have the following meanings.

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

The "melting temperature (melting point)" is a temperature corresponding to the maximum value of the melting peak obtained by analyzing a polymer by a differential scanning calorimetry (DSC) method.

A "glass transition point" is a value measured by analyzing a polymer by a dynamic viscoelasticity measurement (DMA) method.

"A substantially spherical inorganic filler" means an inorganic filler in which the ratio of spherical particles having a ratio of minor axis to major axis of 0.7 or more is 95% or more when observed with a scanning electron microscope (SEM).

The powder composition of the present invention (hereinafter also referred to as “the present composition”) is a unit based on perfluoro(alkylvinyl ether) (PAVE) (PAVE unit) or a unit based on hexafluoropropylene (HFP). A powder of a tetrafluoroethylene-based polymer (hereinafter also referred to as “TFE-based polymer”) containing (HFP unit), and an inorganic filler having a Mohs hardness of 3 to 9 (hereinafter, an inorganic filler having this specific hardness) It includes a powder of a “hard inorganic filler”) and a powder of a thermoplastic aromatic polymer (hereinafter, also referred to as “TAr polymer”).

When the present composition is subjected to melt extrusion molding, the physical properties of the TFE polymer (electrical properties such as low dielectric loss tangent, etc.), the physical properties of the TAr polymer (processability, optical properties, etc.), and the physical properties of the hard inorganic filler (low linear expansion property, etc.) Molded articles, such as a film, which achieved this balance are obtained. Although the reason is not necessarily clear, it thinks as follows.

The TFE-based polymer can be said to be a thermoplastic or crystalline polymer, and is excellent in physical stress resistance and heat resistance, and the powder has a predetermined hardness. Therefore, it is thought that during melt extrusion molding, the powder of the TFE-based polymer in a softened state is densely dispersed in the melted or softened TAr polymer while being pulverized and atomized by a hard inorganic filler. Moreover, at the time of this dispersion|distribution, since the quality (fibrillation etc.) of TFE-type polymer itself does not deteriorate, it is thought that the affinity between any component is not inhibited either.

Accordingly, it is also thought that, when the present composition is subjected to melt extrusion molding, a molded article densely containing a hard inorganic filler having a sea-island structure composed of a sea containing TAr polymer and a fine island phase containing a TFE-based polymer is easily formed. do. Therefore, it is thought that the molded article obtained from this composition becomes a molded article highly equipped with the physical properties of three (TFE-type polymer, TAr polymer, and a hard inorganic filler).

Specifically, the molded article (film, etc.) obtained by melt extrusion molding the present composition has physical properties such as low dielectric constant, low dielectric loss tangent, low coefficient of linear expansion, adhesiveness, and moldability. Such a molded product can be suitably used as a material or member of a printed circuit board. Moreover, it is preferable that the dielectric constant measured at 10 GHz of the molding obtained from this composition is 2.0-4.0.

The TFE-based polymer in the present invention is a polymer containing a TFE unit and a PAVE unit or an HFP unit, that is, a polymer containing a TFE unit and a PAVE unit (PFA-based polymer), or a TFE unit and an HFP unit. It is a polymer (FEP-type polymer), and it is more preferable that it is a PFA-type polymer from a viewpoint that it is more excellent in physical stress resistance and heat resistance, and the adhesiveness becomes higher by forming fine spheroids in a molded object.

As 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-based polymer is preferably 260 to 320°C, more preferably 285 to 320°C.

As a glass transition point of a TFE-type polymer, 75-125 degreeC is preferable and 80-100 degreeC is more preferable.

It is preferable that the TFE-type polymer further has a unit based on another monomer.

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 can be mentioned.

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 a terminal group of the polymer main chain. As the latter TFE-based polymer, 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 a TFE-based polymer having an oxygen-containing polar group prepared by plasma treatment, ionizing radiation treatment, or radiation treatment polymers.

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 a 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)-), 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. Incidentally, 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 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 (alias: hymic anhydride; hereinafter also referred to as “NAH”) and anhydride. Maleic acid is preferable, and NAH is more preferable.

Preferred specific examples of the TFE-based polymer include the polymer (1) comprising TFE units, PAVE units and units based on a monomer having an oxygen-containing polar group, 95.0 to 98.0 mol% of TFE units and 2.0 to 5.0 mol% of PAVE units Polymer (2) which consists of, a polymer containing a TFE unit, and a PMVE unit is mentioned.

These polymers are particularly excellent in physical stress resistance, and when the powder composition is subjected to melt extrusion molding, minute spheroids are formed and a molded article having better adhesion is easily formed.

The polymer (1) is preferably a polymer containing a TFE unit, a PAVE unit, and a monomer having a hydroxyl group-containing group or a carbonyl group-containing group. The polymer (1) is preferably a polymer comprising 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 all units. .

As a specific example of a polymer (1), the polymer of international publication 2018/16644 is mentioned.

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

It is preferable that it is 2.1 mol% or more, and, as for content of PAVE unit in polymer (2), it is more preferable that it is 2.2 mol% or more with respect to all the monomer units.

It is preferable that the polymer (2) does not have an oxygen-containing polar group. In addition, that the polymer (2) does not have an oxygen-containing polar group means that the number of oxygen-containing polar groups that the polymer has per 1×10 ⁶ carbon atoms constituting the polymer main chain is less than 500. 100 or less are preferable and, as for the number of oxygen-containing polar groups, less than 50 are more preferable. The lower limit of the number of oxygen-containing polar groups is usually 0 pieces.

The polymer (2) may be produced using a polymerization initiator or chain transfer agent that does not generate an oxygen-containing polar group as a terminal group of the polymer chain, or may be produced by subjecting a TFE-based polymer having an oxygen-containing polar group to fluorination treatment.

As a method of fluorination treatment, a method using fluorine gas (refer to Unexamined-Japanese-Patent No. 2019-194314, etc.) is mentioned.

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 is preferably a fine particle composed of a TFE-based polymer. As a component other than a TFE-type polymer, a thermoplastic polymer is mentioned, for example. The thermoplastic polymer may be a TAr polymer.

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

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 of the total polymer component, more preferably 15% by mass or less . Further, when the polymer component other than the TFE-based polymer is a TAr polymer, the content of the TAr polymer is preferably 20 mass% or less of the total polymer component, and more preferably 10 mass% or less.

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 carbon are preferable, and silicon oxide (silica), metal oxides (beryllium oxide, cerium oxide, alumina, soda alumina, magnesium oxide, zinc oxide, titanium oxide, etc.) , boron nitride, and magnesium metasilicate (steatite) are more preferable, silica and boron nitride are still more preferable, and silica is particularly preferable. Although a hard inorganic filler may be sufficient as an inorganic filler, In that case, it is a part of the whole amount of the hard inorganic filler contained in the powder composition of this invention, Other is hard inorganic filler powder.

The microparticles|fine-particles containing a TFE-type polymer and an inorganic filler use a TFE-type polymer as a core, The particle|grains which have an inorganic filler on the surface of this core are preferable. Such particles are obtained by, for example, coalescing (collision, agglomeration, etc.) particles of a TFE-based polymer and particles of an inorganic filler.

When the TFE-based polymer powder is a powder containing the TFE-based polymer and fine particles containing an inorganic filler, the TFE-based polymer tends to be 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 comprising fine particles including the TFE-based polymer and the inorganic filler, the amount of the inorganic filler in the powder is preferably 50% by mass or less, and 40% by mass or less with respect to the powder. more preferably. Moreover, when at least one part of an inorganic filler is a hard inorganic filler, 40 mass % or less is preferable with respect to powder, and, as for the quantity of the hard inorganic filler, 30 mass % or less is more preferable.

Further, the fine particles constituting the powder of the TFE polymer may contain additives such as organic fillers, organic pigments, metal soaps, surfactants, ultraviolet absorbers, lubricants, and silane coupling agents, which will be described later. When such additives are included, the amount of such additives in the powder is preferably 10 mass% or less, more preferably 5 mass% or less, relative to the powder.

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

The hard inorganic filler in this invention is an inorganic filler whose Mohs' Hardness is 3-9.

As Mohs' Hardness of a hard inorganic filler, 5 or more are preferable and 6 or more are more preferable. In this case, in melt extrusion molding, the pulverization of the TFE-based polymer powder by the hard inorganic filler is highly likely to proceed.

Although the hard inorganic filler may contain components other than an inorganic component, it is preferable that it consists of an inorganic component. As components other than an inorganic component, organic compounds, such as organic substances used for the surface treatment agent mentioned later, and soft inorganic compounds, such as boron nitride, are mentioned.

As the hard inorganic filler, an inorganic filler made of aluminum nitride, beryllium oxide (beryllia), 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 2 or more types of inorganic components.

It is preferable that a silicon oxide is included as a hard inorganic filler. The hard inorganic filler containing silicon oxide not only has high hardness, but it is easy to promote interaction with a TFE-type polymer. Therefore, it is easy to form the molded object which has a more precise|minute sea-island structure in melt extrusion molding from the molding containing such an inorganic filler. Moreover, the low linear expansibility is especially easy to express.

50 mass % or more is preferable and, as for content of the silicon oxide in a hard inorganic filler, 75 mass % or more is more preferable. As for content of silicon oxide, 100 mass % or less is preferable.

As the hard inorganic filler, a beryllia filler (Mohs hardness: 9), a magnesia filler (Mohs hardness: 5.5), and a silica filler (Mohs hardness: 7) are preferable, and a silica filler is more preferable.

It is preferable that a silica filler is a fused silica filler or an amorphous silica filler. In this case, it is easy to provide the molded article with the low thermal expansibility.

As for the hard inorganic filler, at least a part of the surface may be surface-treated. As a surface treatment agent used for such surface treatment, polyhydric alcohols (trimethylolethane, pentaerythritol, propylene glycol, etc.), saturated fatty acids (stearic acid, lauric acid, etc.), esters thereof, alkanolamines, amines (trimethylamine, triethylamine, etc.), paraffin wax, silane coupling agent, silicon, polysiloxane, and oxides of metals such as aluminum, silicon, zirconium, tin, titanium, and antimony, hydroxides of those metals, hydroxides of those metals, and metals and phosphate.

As the silane coupling agent, a silane coupling agent having a functional group is preferable, 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane , 3-methacryloxypropyltriethoxysilane and 3-isocyanatepropyltriethoxysilane are more preferable.

The average particle diameter of the hard inorganic filler powder (that is, the average particle diameter of the fine particles constituting the hard inorganic filler powder) is preferably 0.01 µm or more, and more preferably 0.1 µm or more. Moreover, 10 micrometers or less are preferable, 2 micrometers or less are more preferable, and 1 micrometer or less is especially preferable.

It is preferable that the average particle diameter of the hard inorganic filler is equal to or less 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, in melt extrusion molding, the pulverization of the powder of the TFE-based polymer by it is highly advanced, and it is easy to form a molded article having a denser sea-island structure.

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

It is preferable that the shape of the microparticles|fine-particles which comprises a hard inorganic filler is substantially spherical shape. In the spherical particles occupying 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, and more preferably 0.9 or more. The ratio is preferably less than 1.

The powder of the hard inorganic filler which consists of substantially spherical microparticles|fine-particles is easy to promote interaction with each component in melt extrusion molding.

Preferred specific examples of the hard inorganic filler powder include silica fillers having an average particle diameter of 1 μm or less (“Adma Fine” series manufactured by Admatex, etc.), spherical fused silica having an average particle diameter of more than 0.10 μm and 0.5 μm or less (Denka Corporation). manufactured "SFP" series, etc.) are mentioned.

As the TAr 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 melt phase, and is generally called a thermotropic liquid crystal polymer. Specific examples of the liquid crystal polymer include thermoplastic and liquid crystalline aromatic polyesters and aromatic polyester amides, the former being called thermotropic liquid crystalline polyester and the latter being called thermotropic liquid crystalline polyester amide in many cases. An imide bond, a carbonate bond, a carbodiimide bond, an isocyanurate 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-based polymer and the hard inorganic filler are highly dispersed in the TAr polymer to form a molded article.

For this reason, the anisotropy of the physical properties derived from the liquid crystal polymer in the flow direction (MD direction) of the molded product, which is easily expressed when the TAr polymer is a liquid crystal polymer, is easily alleviated by the highly dispersed TFE-based polymer or hard inorganic filler. . In other words, a molded article (such as a film) obtained by melt extrusion molding from the present composition in which the TAr polymer is a liquid crystal polymer tends to have high isotropy.

As a result, it is easy to obtain a molded article in which a decrease in tensile strength and thermal expansibility due to anisotropy is suppressed while having physical properties inherent to the liquid crystal polymer (mechanical properties such as strength, elasticity and vibration absorption, and electrical properties such as dielectric properties). . In particular, it is easy to obtain a molded article such as a film having excellent dimensional stability during chemical immersion or heat treatment.

The anisotropic melt phase of the liquid crystal polymer may be confirmed by, for example, placing the polymer sample on a hot stage, heating the polymer sample at an elevated temperature in a nitrogen gas atmosphere, and observing the transmitted light of the polymer sample.

250-370 degreeC is preferable and, as for the melting temperature (melting point) of a liquid crystal polymer, 270-350 degreeC is more preferable.

Specific examples of the liquid crystal polymer TAr polymer include “Laferose” manufactured by Polyplastics, “Vectra” manufactured by Celanese, “UENOLCP” manufactured by Ueno Pharmaceutical, “Sumika Super LCP” manufactured by Sumitomo Chemical, and SOLVAY SPECIALTY POLYMERS. "XYDAR" manufactured by the company, "Zyder" manufactured by JX Nikko Niseki Energy, and "Siberas" manufactured by Toray Corporation are mentioned.

The TAr polymer powder 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 microparticles|fine-particles which comprise the said powder may be microparticles|fine-particles containing components other than TAr polymer. Examples of such components include thermoplastic polymers other than TAr polymer, 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. Additives, such as these are mentioned. The thermoplastic polymer other than the TAr polymer may be a TFE polymer, and the non-fibrous inorganic filler may be a hard inorganic filler.

Examples of components other than the TAr polymer include glass fibers, carbon fibers (PAN-based carbon fibers, pitch-based carbon fibers), organic synthetic fibers (aromatic polyamide fibers, etc.), metal fibers (stainless steel fibers, aluminum fibers, etc.), inorganic fibers (carbonized fibers). Fibrous fillers, such as silicon fiber, potassium titanate fiber, alumina fiber, etc.) and natural ore type fiber (wollastonite, asbesto, etc.) are preferable.

When the powder fine particles of the TAr polymer contain a fibrous filler, the content of the fibrous filler in the powder is preferably 40 mass% or less, more preferably 35 mass% or less.

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

When the powder fine particles of the TAr polymer contain additives other than the above such as non-fibrous inorganic fillers, the content of these additives in the powder is preferably 30 mass% or less, more preferably 15 mass% or less. However, when an additive is a hard inorganic filler, 20 mass % or less is preferable with respect to powder, and, as for the quantity of the hard inorganic filler, 10 mass % or less is more preferable.

The average particle diameter of the TAr polymer powder (that is, the average particle diameter of 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-based polymer and the hard inorganic filler are dispersed in the TAr polymer to easily form a molded article having a dense sea-island structure.

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

Examples of the other powder include powders of thermoplastic polymers other than TFE polymers and TAr polymers, powders of polymers other than thermoplastic polymers, powders of fillers other than hard inorganic fillers (the inorganic fillers, organic fillers, etc.). 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-based polymers (polyethylene, polypropylene, polybutylene, acid-modified polyethylene, acid-modified polypropylene, acid-modified polybutylene, etc.), fluorine-based polymers other than TFE-based polymers (polyvinylidene fluoride, polytetrafluoroethylene, etc.), styrene-based polymers (polystyrene, polyacrylonitrile styrene, polyacrylonitrile-butadiene styrene, etc.), polycarbonate-based polymers, poly(meth)acrylic-based polymers, polyvinyl chloride, polyarylate-based polymers, Polyurethane-type polymer is mentioned.

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

Examples of the organic filler powder include aromatic polyamide fibers, polyaramid fibers, polyparaphenylenebenzoxazole fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers, polyethylene fibers, and the like. .

When this composition contains the said other powder, 30 mass % or less is preferable and, as for content of the other powder in this composition, 15 mass % or less is more preferable.

The present composition is particularly preferably a composition composed of three types of powder: TFE-based polymer powder, hard inorganic filler powder, and TAr polymer powder. The content ratio of these three powders in this composition below means the ratio in the composition which consists of these three types of powder.

As content of the TFE-type polymer in this composition, 5 mass % or more is preferable, and 10 mass % or more is more preferable. Moreover, 50 mass % or less is preferable, and 40 mass % or less is more preferable.

As content of TAr polymer in this composition, 10 mass % or more is preferable, and 20 mass % or more is more preferable. Moreover, 90 mass % or less is preferable, and 80 mass % or less is more preferable.

It is preferable that the content of the TAr polymer in the present composition is higher than the content of the TFE-based polymer. In short, it is preferable that the present composition contains a TAr polymer as a main polymer component. In this case, since the interaction with the TFE-based polymer tends to be enhanced, it is easy to form a molded article having a denser sea-island structure in melt extrusion molding. Moreover, the low linear expansibility is especially easy to express.

As content of the hard inorganic filler in this composition, 5 mass % or more is preferable, and 10 mass % or more is more preferable. Moreover, 50 mass % or less is preferable, and 40 mass % or less is more preferable.

As ratio of content of the hard inorganic filler with respect to content of a TFE-type polymer in this composition, 0.2-1.0 is preferable and 0.2-0.6 are more preferable. In this case, in melt extrusion molding, the powder of the TFE-based polymer is highly pulverized, and a molded article in which the hard inorganic filler is highly dispersed is easily obtained. Moreover, in a molded article, it is easy to provide the physical property of three characters highly.

The content of each of the TFE-based polymer, the TAr polymer, and the 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.

It is preferable to dry blend each component, and to manufacture this composition. In the case of dry blending, mixing apparatuses, such as a tumbler, a Henschel mixer, a hopper, a Banbury mixer, a roll, and a Brabender, can be used.

It is preferable that this composition is used for melt extrusion molding, and it is preferable to shape|mold into a film by melt extrusion molding.

Melt extrusion molding is preferably carried out by a method using a T-die, melt-kneading the present composition charged from a hopper in an extruder (single screw or twin screw), and extruding from a T-die installed at the tip of the extruder to make a film It is more preferable to carry out by the method of molding.

The film obtained by melt extrusion molding is preferably further subjected to a stretching treatment. Thereby, a more isotropic film is obtained. An extending|stretching process is a process of softening a film at the temperature below the melting|fusing point, and extending|stretching in one direction (1-axis: MD direction) or two directions (two-axis: MD direction and TD direction).

From the viewpoint of obtaining an isotropic film, the stretching treatment is more preferably a biaxial stretching treatment.

An inflation method and a flat method are mentioned as an extending|stretching method. As a flat system, either system of simultaneous biaxial stretching and sequential biaxial stretching is employable.

In manufacture of the film by melt-extrusion molding, you may give a lamination process, an extending|stretching process, a cooling process, and a peeling process to the film obtained further.

Lamination process is a process which laminates a peeling film on both surfaces or single side|surface of the film obtained, and forms a laminated body.

As a lamination method, a thermocompression bonding method and a surface treatment method are mentioned, In that case, a thermocompression bonding roll, a hot press apparatus, and a laminator are used.

For example, when using a thermocompression bonding roll, what is necessary is just to overlap the film obtained and a peeling film, to pass through a thermocompression bonding roll, and to perform thermocompression bonding.

In the case of using a hot press device, the film obtained on the bottom plate of the hot press device and the release film may be laminated, thermocompression-bonded, and cooled.

Moreover, using a pair of thermocompression bonding rolls, you may supply this composition in a molten state extruded from a T-die to the clearance gap of two peeling films, and you may shape|mold a laminated body in the clearance gap part of this thermocompression bonding roll.

In the formation of this laminate, if a coextrusion method using a multilayer die is used, a multilayer body in which a film formed of the present composition and a release film are respectively used as layers can be formed.

Examples of the release film material include polyethylene, polypropylene, polyetheretherketone, polyethersulfone, 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 fluoride, polyvinylidene fluoride, poly 3 Ethylene fluorochloride is mentioned.

10-200 micrometers is preferable and, as for the thickness of a peeling film, 20-100 micrometers is more preferable.

An extending|stretching process is a process which extends|stretches the said laminated body, and obtains a stretched product, softening the peeling film layer of the laminated body obtained by lamination|stacking process. You may perform this extending|stretching process continuously.

A cooling process is a process which cools the stretched material obtained by an extending|stretching process. Natural cooling may be carried out and cooling may use a cooling roll etc.

A peeling process is a process which peels a peeling film from the cooled stretched material. A peeling process can be performed by the 90 degree peeling method or the 180 degree peeling method.

By such a series of processes, the film by which the coefficient of thermal expansion was suppressed more is obtained from this composition.

In shaping|molding of a film, you may use inflation shaping|molding.

In inflation molding, since 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), the isotropy of the film tends to improve. In inflation molding, since the melt-kneaded product is mechanically stretched in two directions by taking-up and expansion, it is easy to form a film in which polymer molecules are oriented in two directions.

Moreover, you may form the film of the structure similar to the laminated body mentioned above by inflation molding at this time.

That is, this composition and another thermoplastic polymer are melt-extruded from an annular die, and it is set as a laminated body by inflation molding.

Examples of the laminate that can be formed at this time include a two-layer laminate (Type 1) consisting of a film layer formed of one present composition and one release film layer, and a film layer formed of one present composition between two release film layers. a three-layer laminate (Type 2) sandwiched therebetween, and a three-layer laminate (Type 3) in which one release film layer is sandwiched between two film layers formed of the present composition; A laminate or a laminate of type 3 is preferred.

As thickness of the film layer formed from this composition in these laminated bodies, 3-150 micrometers is preferable. Moreover, as thickness of a peeling film layer, the thickness of the said film layer or more and 2 times or less are preferable.

Also by such a series of processes, the film by which the thermal expansion coefficient was suppressed more is obtained from this 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 Mohs hardness of 3 to 9, and a TAr polymer, and a sea and TFE-based polymer containing a TAr polymer. It has a sea-island structure composed of an island including

In the present film, the definitions of the TFE-based polymer, the hard inorganic filler, and the TAr polymer are the same as those in the present composition, including preferred ranges.

In the present film, the TFE-based polymer, the hard inorganic filler, and the TAr polymer may be present in a uniformly distributed manner, or may exist in an unbalanced manner.

It is preferable that the distribution amount of the TFE-type polymer in the surface region in the thickness direction of the present film is higher than the distribution amount of the TFE-type polymer in the central region in the thickness direction of the film. In this case, the physical properties resulting from the TFE-based polymer in the present film (especially dielectric properties such as low dielectric loss tangent and adhesive properties) are remarkably easily expressed.

It is preferable that the distribution amount of the hard inorganic filler in the center area|region in the thickness direction of this film is higher than the distribution amount of the hard inorganic filler in the surface area in the thickness direction of a film. In this case, the physical properties (especially, low linear expansion property, etc.) resulting from the hard inorganic filler in this film are remarkably easy to express.

As thickness of this film, 5-1000 micrometers is preferable and 10-200 micrometers is more preferable.

It is preferable to manufacture this film by melt extrusion molding of this composition. In this case, it is easy to manufacture the film of the various arbitrary aspects mentioned above, without impairing workability, such as mechanical strength and bendability.

It is preferable to use the T-die coating method as a manufacturing method of this film, Specifically, it is preferable to discharge the melt-kneaded present composition from a T-die in a molten state, and to make contact with a cooling roll, and to shape|mold into a film. It is preferable that the melt-kneaded composition be heated and maintained in a non-contact heating unit before being brought into contact with a cooling roll.

It is preferable that this composition cooled by a cooling roll is shape|molded into a film shape while conveying by a conveyance roller, is wound up with a winding roll, and is shape|molded into a long film.

It is preferable that this film forms a metal layer on the surface, and sets it as a metal-clad laminate. As a metal, various metals, such as copper, nickel, aluminum, silver, gold|metal|money, tin, and these alloys (stainless steel etc.) are mentioned.

As such a metal-clad laminate, the single-sided metal-clad laminate which has a metal layer and this film in this order, and the double-sided metal-clad laminate which has a metal layer, this film layer, and a metal layer in this order is mentioned. Moreover, these metal-clad laminates may have further other layers (prepreg layer, glass member layer, ceramic member layer, another resin film layer).

As a method of forming a metal layer on the surface of the film, a method of adhering a metal foil to the surface of the film by a lamination method or a thermocompression bonding method, a method of forming a metal layer on the surface of the film by a sputtering method or a vapor deposition method, a plating method (including electroless plating and electrolytic plating after electroless plating.) by a method of forming a metal layer on the surface of the present film by The method of forming a metal layer on the surface of this film is mentioned.

Moreover, as metal foil, copper foils, such as a rolled copper foil and an electrolytic copper foil, are preferable.

In order to further improve adhesiveness with a metal layer, you may surface-treat the surface of this film. Plasma treatment, corona treatment, flame treatment, and ytto treatment are mentioned as surface treatment.

Such a metal-clad laminate can be used as a material or member for a printed circuit board, a high heat dissipation board, and an antenna board.

For example, if the metal layer of such a metal clad laminate is etched and a pattern circuit is formed, a printed circuit board will be obtained. 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.

Moreover, a soldering resist may be laminated|stacked on a pattern circuit, and a coverlay film may be laminated|stacked. A coverlay film is typically comprised from a base film and the adhesive bond layer formed in the surface, and the surface by the side of an adhesive bond layer is affixed to a printed circuit board. As a base film of a coverlay film, you may use this film. Moreover, on a pattern circuit, you may form the interlayer insulating film (adhesive layer) using this film, and you may laminate|stack a polyimide film as a coverlay film.

Example

Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

The raw materials used are shown below.

1. Preparation of each ingredient

PFA-based powder 1: A PFA-based polymer having 1000 carbonyl group-containing groups per 1 × 10 ⁶ main chain carbon atoms containing 98.0 mol%, 0.1 mol%, 1.9 mol% of TFE units, NAH units and PPVE units in this order ( Melting temperature: 300°C) powder (average particle diameter: 2.0 µm)

PFA-based powder 2: Powder consisting of a PFA-based polymer (melting temperature: 305°C) having 40 carbonyl group-containing groups composed of TFE units and PPVE units per 1 × 10 ⁶ main chain carbon atoms (average particle diameter: 2.4 µm)

Aromatic powder 1: A liquid crystal polymer powder that is an aromatic polymer containing 30% by mass of glass fiber (melting temperature: 320° C.; manufactured by Ueno Pharmaceutical Co., Ltd., “UENO LCP 6030G”)

Inorganic filler 1: Mohs hardness is 7, and a substantially spherical silica filler (average particle diameter: 0.5 µm; manufactured by Admatex, "Adma Fine SO-C2")

Inorganic filler 2: Silica filler having a Mohs hardness of 7 and having a substantially spherical shape (average particle diameter: 5 µm)

Inorganic filler 3: Mohs hardness is 1, talc filler (average particle diameter: 0.7 μm)

Evaluation of the dimensional stability of the film was based on JIS C 6481: 1996.

A 30 cm square sample having two sides along the flow direction and two sides along the width direction was cut out from the edge of the obtained film in the width direction.

On the diagonal of the surface of this sample (the 45° direction in which the angle formed with the flow direction is 45°, and the 135° direction orthogonal to the 45° direction), a line segment of 25 cm in length is drawn, and the amount of each line segment is Punch holes were formed centered on each end.

The sample was immersed in an aqueous iron chloride solution, the distance between the centers of two punch holes before and after immersion was measured, and the stretch rate of the diagonal direction of the film in etching was calculated|required.

After heating the sample at 150 ° C. for 30 minutes, heat treatment to cool to 25 ° C. is performed, the distance between the centers of the two punch holes before and after the heat treatment is measured, and the stretch rate in the oblique direction of the film in the heat treatment is determined did.

2. Preparation of powder composition and film

[Example 1]

The PFA-based powder 1 (20 parts by mass), the aromatic powder 1 (100 parts by mass), and the hard inorganic filler 1 (15 parts by mass) were dry blended to prepare a powder composition 1. Powder composition 1 was put into a twin-screw extruder (manufactured by Technobel, "KZW15TW-45MG"), melt-kneaded (screw rotation speed: 200 rpm, set resin temperature: 370° C.), and 2.0 kg from a T-die installed at the tip It discharged at /hr to shape|mold the flat film 1 (thickness: 100 micrometers).

Film 1 showed high adhesiveness with respect to copper foil, the dielectric constant was 2.9, and was excellent in the dielectric characteristic. Moreover, both the stretching rate in the diagonal direction of the film in the etching of the film 1 and the stretching rate (absolute value) in the diagonal direction of the film in the heat treatment were less than 0.1%, and the film 1 was excellent in dimensional stability. .

[Examples 2 to 4]

Except having changed the kind and quantity of each powder and inorganic filler as shown in following Table 1, it carried out similarly to Film 1, and obtained Films 2-4.

3. Evaluation

3-1. Evaluation of dimensional thermal stability

The dimensional change rate of each film was measured as follows, and it evaluated according to the following criteria. In addition, evaluation of the dimensional stability of a film was based on JIS C 6481: 1996.

From each film, a 30 cm square sample was cut out.

A line segment with a length of 25 cm was drawn on the surface of this sample, and punch holes were formed centering on both ends of the line segment.

After heating the sample at 150 ° C. for 30 minutes, heat treatment to cool to 25 ° C. is performed, the distance between the centers of two punch holes before and after the heat treatment is measured, and the absolute value of the expansion and contraction rate of the film in the heat treatment is measured. It was set as the rate of thermal change.

[Evaluation standard]

○: Dimensional thermal change rate is less than 1.5%

△: Dimensional thermal change rate of 1.5 or more and 2% or less

×: Dimensional thermal change rate exceeds 2%

3-2. Adhesion evaluation

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

Each of the films and the copper foil were placed facing each other, and hot-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 laminate. The copper foil layer was peeled from the film layer to the position of 50 mm from the one end of the longitudinal direction of a test piece. At the time of peeling, a position of 50 mm from one end in the longitudinal direction of the test piece is taken as the center, and using a tensile tester (manufactured by Orientec Co., Ltd.), peeled at 90 degrees at a tensile rate of 50 mm/min, and a measurement distance of 10 mm to 30 The average load to mm was measured and it was set as peeling strength (N/cm).

[Evaluation standard]

(circle): Peeling strength is 10 N/cm or more.

(triangle|delta): Peeling strength is 5 N/cm or more and less than 10 N/cm.

x: Peeling strength is less than 5 N/cm.

Each film was frozen in liquid nitrogen, then cut, and the cut surface was observed with a scanning electron microscope (manufactured by Hitachi High-Technologies, FE-SEM). As a result, Films 1 to 4 were the resolution containing liquid crystal polymer 1. And it had a sea-island structure composed of an island phase containing the PFA-based polymer 1 or 2. Moreover, in films 1-3, the distribution amount of the PFA-type polymer in the surface area in the thickness direction of the film was higher than the distribution amount of the PFA-type polymer in the center area|region in the thickness direction of the film.

The powder composition of the present invention and the film of the present invention have high-frequency characteristics, particularly electronic devices requiring reduction of transmission loss in the millimeter wave band (radars, network routers, backplanes, wireless infrastructure, automobile sensors, engine management sensors, etc.) It is useful as a material or member of a printed circuit board used for

In addition, the specification of Japanese Patent Application No. 2019-204147, a claim, and the abstract for which it applied on November 11, 2019 is referred here, and it takes in as an indication of this specification.

Claims (15)

A tetrafluoroethylene polymer powder containing a unit based on perfluoro (alkylvinyl ether) or a unit based on hexafluoropropylene, an inorganic filler powder having a Mohs hardness of 3 to 9, and a thermoplastic aromatic A powder composition comprising polymer powder. The method of claim 1,
The powder composition, wherein the tetrafluoroethylene-based polymer is a polymer having an oxygen-containing polar group including units based on tetrafluoroethylene and units based on perfluoro(alkylvinyl ether). 3. The method according to claim 1 or 2,
The powder composition wherein the inorganic filler is a filler containing silicon oxide. 4. The method according to any one of claims 1 to 3,
The powder composition wherein the aromatic polymer is polyimide, polyamideimide, polyester, polyesteramide, polyphenylene ether or polyphenylene sulfide. 5. The method according to any one of claims 1 to 4,
The powder composition, wherein the aromatic polymer is a liquid crystal polymer. 6. The method according to any one of claims 1 to 5,
The powder composition, wherein the average particle diameter of the powder of the tetrafluoroethylene polymer is larger than the average particle diameter of the inorganic filler. 7. The method according to any one of claims 1 to 6,
The powder composition, wherein the content of the aromatic polymer is higher than the content of the tetrafluoroethylene-based polymer. 8. The method according to any one of claims 1 to 7,
A powder composition wherein a ratio of the content of the inorganic filler to the content of the tetrafluoroethylene-based polymer is 0.2 to 0.6. 9. The method according to any one of claims 1 to 8,
The content of the tetrafluoroethylene-based polymer, the content of the inorganic filler, and the content of the aromatic polymer are, in this order, 10 to 40 mass%, 5 to 40 mass%, and 20 to 85 mass%, a powder composition. 10. The method according to any one of claims 1 to 9,
A powder composition 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. A tetrafluoroethylene polymer comprising a unit based on perfluoro (alkylvinyl ether) or a unit based on hexafluoropropylene, an inorganic filler having a Mohs hardness of 3 to 9, and a thermoplastic aromatic polymer, , a film having at least a sea-island structure composed of a sea containing the aromatic polymer and an island phase containing the tetrafluoroethylene-based polymer. 13. The method of claim 12,
The film, 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. 14. The method according to claim 12 or 13,
The film whose distribution amount of the said inorganic filler in the center area|region in the thickness direction of the said film is higher than the distribution amount of the said inorganic filler of the surface area in the thickness direction of the said film. 15. The method according to any one of claims 12 to 14,
The film has a thickness of 5 to 1000 μm.