KR20240065068A - Composition, method of making the composition and method of making the sheet - Google Patents

Abstract

The composition includes particles containing polytetrafluoroethylene, particles containing a heat-meltable tetrafluoroethylene-based polymer, a liquid compound having a surface tension of less than 72 dyn/cm, or water and a surfactant. Here, the mass-based content of the liquid compound or water is less than the total mass-based content of the particles containing polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene-based polymer. The surface tension of the mixture of water and surfactant is less than 72 dyn/cm.

Description

Composition, method of making the composition and method of making the sheet

The present disclosure relates to compositions, methods of making compositions, and methods of making sheets.

Polytetrafluoroethylene has excellent physical properties such as electrical insulation, water and oil repellency, chemical resistance, and heat resistance. For this reason, dispersions in which polytetrafluoroethylene particles are dispersed in water or an oil-based solvent are useful as materials for forming resists, adhesives, electrical insulating layers, lubricants, inks, paints, etc.

When polytetrafluoroethylene is used as the material, functional particles such as fluorine resins other than polytetrafluoroethylene and inorganic particles may be used together with polytetrafluoroethylene.

However, polytetrafluoroethylene has low surface energy, and its particles tend to agglomerate. Additionally, since the affinity between polytetrafluoroethylene particles and functional particles is low, it may be difficult to mix them without causing aggregation of the two.

As an example of a method of mixing a fluorine resin and inorganic particles, for example, a method of separately preparing co-agglomerated powder obtained from a dispersion containing polytetrafluoroethylene particles and inorganic particles and preparing a paste from it (Japanese publication) (see Patent Publication No. 2015-44288) is known. In addition, a method of preparing a paste by mixing a mixture of polytetrafluoroethylene particles, copolymer particles of tetrafluoroethylene and perfluoropropyl vinyl ether, and inorganic particles with a large amount of naphtha, a molding aid (Japanese Patent Publication 2015) -Refer to paragraph number “0050” of No. 164801) is known.

However, the method described in Japanese Patent Application Laid-Open No. 2015-44288 requires separate preparation of co-agglomerated powder, and is a method with low production efficiency. In addition, the method described in Japanese Patent Application Laid-Open No. 2015-164801 uses a large amount of naphtha as a molding aid to disperse polytetrafluoroethylene particles, etc., so removal of the molding aid is necessary and production efficiency is low.

The present disclosure has been made in consideration of the above-mentioned conventional circumstances, and the present disclosure is a composition that can shorten the process and time required for molding a molded article and can form a molded article with suppressed powder fall-off and generation of aggregates, The purpose is to provide a method for producing this composition and a method for producing a sheet using this composition.

Specific means to achieve the above task are as follows.

<1> Comprising particles containing polytetrafluoroethylene, particles containing a heat-meltable tetrafluoroethylene-based polymer, and a liquid compound having a surface tension of less than 72 dyn/cm, the polytetrafluoroethylene A composition in which the mass-based content of the liquid compound is less than the total mass-based content of the particles and the heat-meltable tetrafluoroethylene-based polymer.

<2> The composition according to <1>, wherein the liquid compound contains at least one selected from the group consisting of hydrocarbons and alcohols.

<3> The composition according to <1> or <2>, wherein the liquid compound contains at least one selected from the group consisting of ethylene glycol, glycerin, and propylene glycol.

<4> Particles containing polytetrafluoroethylene, particles containing a heat-meltable tetrafluoroethylene polymer, water, and a surfactant, particles containing the polytetrafluoroethylene, and the above A composition wherein the content based on the mass of the water is less than the total content based on the mass of the particles containing a heat-meltable tetrafluoroethylene polymer, and the surface tension of the mixture of the water and the surfactant is less than 72 dyn/cm.

<5> The composition according to any one of <1> to <4>, wherein the heat-meltable tetrafluoroethylene-based polymer has a melting temperature of 200 to 320°C.

<6> The composition according to any one of <1> to <5>, wherein the heat-meltable tetrafluoroethylene polymer has an oxygen-containing polar group.

<7> The ratio of the particles containing the polytetrafluoroethylene to the total of the particles containing the polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene polymer is 40 to 80 mass. % Phosphorus The composition according to any one of <1> to <6>.

<8> The composition according to any one of <1> to <7>, further comprising inorganic particles.

<9> The composition according to <8>, wherein the inorganic particles include at least one selected from the group consisting of silica, boron nitride, and titanium dioxide.

<10> The composition according to <8> or <9>, wherein the content of the inorganic particles is 15% by mass or more based on the total amount of the composition.

<11> The composition according to any one of <1> to <10>, further comprising an aromatic polymer or a precursor thereof.

<12> The composition according to any one of <1> to <11>, which is a kneaded product.

<13> Particles containing polytetrafluoroethylene, particles containing a heat-meltable tetrafluoroethylene polymer, and a liquid compound having a surface tension of less than 72 dyn/cm are kneaded, and the polytetrafluoroethylene is mixed. A method for producing a composition, wherein a composition is obtained in which the mass-based content of the liquid compound is less than the total mass-based content of the particles containing it and the particles containing the heat-meltable tetrafluoroethylene-based polymer.

<14> Particles containing polytetrafluoroethylene, particles containing a heat-meltable tetrafluoroethylene-based polymer, water, and a surfactant are mixed, and the particles containing the polytetrafluoroethylene and the above are mixed. Obtaining a composition in which the mass-based content of the water is less than the total mass-based content of particles containing a heat-meltable tetrafluoroethylene polymer, and the surface tension of the mixture of the water and the surfactant is less than 72 dyn/cm, Method for producing the composition.

<15> A method for producing a sheet, wherein a sheet is obtained by molding the composition according to any one of <1> to <12>.

According to the present disclosure, a composition that can shorten the processes and time required for molding a molded product and form a molded product with suppressed powder fall-off and generation of agglomerates, a method for producing the composition, and a method using the composition A method of manufacturing a sheet is provided.

Hereinafter, embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not essential, unless specifically stated. The same applies to the numerical values and their ranges, and do not limit the present disclosure.

In the present disclosure, the numerical range indicated using “~” includes the numerical values written before and after “~” as the minimum and maximum values, respectively.

In the numerical range described stepwise during the present disclosure, the upper limit or lower limit value described in one numerical range may be replaced with the upper limit or lower limit value of another numerical range described stepwise. In addition, in the numerical range described in the present disclosure, the upper or lower limit of the numerical range may be replaced with the value shown in the synthesis example.

In the present disclosure, each component may contain multiple types of corresponding substances. When multiple types of substances corresponding to each component exist in the composition, the content rate or content of each component means the total content rate or content of the multiple types of substances present in the composition, unless otherwise specified.

In the present disclosure, the particles corresponding to each component may contain multiple types of particles. When multiple types of particles corresponding to each component exist in the composition, the particle diameter of each component means the value for the mixture of the multiple types of particles present in the composition, unless otherwise specified.

In the present disclosure, the word “layer” includes cases where the layer is formed in the entire area when observing the area where the layer exists, as well as cases where the layer is formed only in a part of the area.

In the present disclosure, the word “lamination” indicates stacking layers, and two or more layers may be combined, and two or more layers may be detachable.

In the present disclosure, “polymer” is a compound formed by polymerizing monomers. In other words, “polymer” has a plurality of units based on monomers.

In the present disclosure, “unit” in a polymer means an atomic group based on the monomer formed by polymerization of the monomer. The unit may be a unit formed directly through a polymerization reaction, or may be a unit in which a part of the unit is converted into a different structure by processing the polymer. Hereinafter, the unit based on monomer a is also simply described as “monomer a unit.”

In the present disclosure, “melting temperature” is the temperature corresponding to the maximum value of the melting peak of the polymer measured by differential scanning calorimetry (DSC).

In the present disclosure, “melt flow rate” means the melt mass flow rate of a polymer as defined in JIS K 7210-1:2014 (ISO1133-1:2011).

In the present disclosure, “glass transition point (Tg)” is a value measured by analyzing a polymer using a dynamic viscoelasticity measurement (DMA) method.

In the present disclosure, the “volume average particle diameter (D50)” of the particles is the cumulative 50% diameter based on the volume of the particles, which is determined by a laser diffraction/scattering method. That is, the particle size distribution is measured by a laser diffraction/scattering method, a cumulative curve is obtained with the total volume of the particle population being 100%, and the point on the cumulative curve at which the cumulative volume is 50% is the particle size.

The D50 of a particle is obtained by dispersing the particle in water and analyzing it by a laser diffraction/scattering method using a laser diffraction/scattering type particle size distribution measuring device (e.g., LA-920 measuring instrument manufactured by Horiba Seisakusho). .

In the present disclosure, the “aspect ratio” of a particle refers to the ratio of the major axis to the minor axis (major axis/minor axis) when the particle is observed with an SEM. The aspect ratio of the particles is the average value of the aspect ratios of 100 randomly selected and measured particles.

In the present disclosure, the “specific surface area” is a value calculated by measuring particles by the gas adsorption (constant volume method) BET multipoint method, and is obtained using NOVA4200e (manufactured by Quantachrome Instruments).

In this disclosure, “surface tension” refers to a value measured under conditions of 25°C by the plate method (Wilhelmy method). Surface tension can be measured using an automatic surface tension meter CBVP-Z type (manufactured by Kyowa Interface Science Co., Ltd.).

The first composition of the present disclosure contains particles (hereinafter also referred to as PTFE particles) containing polytetrafluoroethylene (hereinafter also referred to as PTFE) and a heat-meltable tetrafluoroethylene-based polymer (hereinafter also referred to as PTFE). PTFE comprising particles containing (hereinafter also referred to as F polymer) (hereinafter also referred to as F particles) and a liquid compound (hereinafter also referred to as a specific liquid compound) having a surface tension of less than 72 dyn/cm. It is a composition in which the mass-based content of the specific liquid compound is lower than the total mass-based content of the particles and the F particles.

The second composition of the present disclosure includes PTFE particles, F particles, water, and a surfactant, and the content by mass of the water is less than the total content by mass of the PTFE particles and the F particles, and the water and the surface tension of the mixture of the surfactant is less than 72 dyn/cm.

Additionally, the unit of surface tension “dyn/cm” is the same as “mN/m”, and 1 dyn/cm is 1 mN/m.

Hereinafter, the first composition and the second composition are collectively referred to as the present composition.

With this composition, the processes and time required for molding a molded product can be shortened, and a molded product with suppressed powder fall-off and generation of aggregates can be formed. Although the reason is not clear, it is inferred as follows.

In addition to PTFE particles, this composition uses F particles containing F polymer, which has high homogeneity with PTFE and is relatively easy to interact with components other than PTFE. Therefore, in this composition, the presence of F particles promotes the interaction between PTFE particles and components other than PTFE particles.

In addition, since both PTFE and F polymer are resins with low surface tension, the wettability of the F particles is promoted by the composition containing a specific liquid compound with low surface tension, or water and a surfactant, thereby improving the wettability of the PTFE particles. It is promoted.

As a result, it is assumed that if the content of the specific liquid compound or water in the present composition is less than the total content of the PTFE particles and F particles, the PTFE particles and F particles are well mixed and uniformly distributed, and the generation of aggregates is suppressed. .

By being able to reduce the specific liquid compound or water contained in the present composition, the removal time for the specific liquid compound or water can be shortened when obtaining a molded article using the present composition. As a result, according to this composition, the time required for molding a molded article can be shortened.

In addition, it is assumed that by suppressing the generation of aggregates, the falling off of powder from the molded product obtained by molding the present composition is suppressed. Furthermore, it is assumed that by suppressing the generation of aggregates, the physical properties such as electrical properties and adhesiveness of the molded product obtained by molding the present composition are improved.

Hereinafter, each component constituting the present composition will be described.

PTFE may be a homopolymer of tetrafluoroethylene (hereinafter also referred to as TFE), a trace amount of perfluoro(alkylvinyl ether) (hereinafter also referred to as PAVE), or hexafluoropropylene (hereinafter referred to as HFP). ), so-called modified PTFE, which is a copolymer of TFE and a comonomer such as fluoroalkyl ethylene, may be used. The proportion of TFE units in PTFE is 99.5 mol% or more of all units, and is preferably 99.9 mol% or more.

PTFE is preferably non-heat meltable.

PTFE is preferably PTFE with a number average molecular weight (Mn) calculated based on the following formula (1) of 200,000 or more.

Mn = 2.1 × 10 ¹⁰ × ΔHc ^-5.16 ... (One)

In formula (1), Mn represents the number average molecular weight of PTFE, and ΔHc represents the heat of crystallization (cal/g) of PTFE measured by differential scanning calorimetry.

The D50 of the PTFE particles is preferably 0.1 μm or more, and more preferably 0.2 μm or more. The D50 of the PTFE particles is preferably 3 μm or less, and more preferably 0.5 μm or less.

The content of PTFE particles in this composition is preferably 5 to 60 mass%, more preferably 10 to 50 mass%, and still more preferably 10 to 40 mass%.

The content of PTFE particles in this composition may be 10 to 60 mass%, 12 to 50 mass%, or 12 to 40 mass% from the viewpoint of the stretching strength of the formed sheet.

The specific surface area of the PTFE particles is preferably 1 to 20 m ² /g.

One type of PTFE particle may be used, or two or more types may be used.

The PTFE particles may contain components other than PTFE, but particles made of PTFE are preferable. The PTFE content in the PTFE particles is preferably 90% by mass or more, and more preferably 99% by mass or more.

Other components that may be included in PTFE particles include other resins or inorganic compounds described later.

F polymer is heat meltable.

A heat-meltable polymer refers to a polymer at which a melt flow rate is 1 to 1000 g/10 min under the condition of a load of 49 N.

The melting temperature of the F polymer is preferably 200°C or higher, and more preferably 260°C or higher. The melting temperature of the F polymer is preferably 320°C or lower, and more preferably 310°C or lower.

The glass transition point of the F polymer is preferably 50°C or higher, and more preferably 75°C or higher. The glass transition point of the F polymer is preferably 150°C or lower, and more preferably 125°C or lower.

The fluorine content of the F polymer is preferably 70% by mass or more, and more preferably 72 to 76% by mass.

The surface tension of the F polymer is preferably 16 to 26 dyn/cm. In addition, the surface tension of the F polymer can be measured by placing a droplet of a wet index reagent (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) on a flat plate made of the F polymer.

F polymers with a high fluorine content have excellent physical properties such as electrical properties, but have low surface tension and tend to have low affinity with other components such as liquid compounds. However, since the present composition contains a liquid compound with low surface tension, or water and a surfactant, it is presumed that the PTFE particles and F particles are well mixed and uniformly distributed, thereby suppressing the generation of aggregates.

The F polymer may be a polymer containing TFE units and trace amounts of other units.

F polymers are polymers containing TFE units and ethylene-based units, polymers containing TFE units and propylene-based units, polymers containing TFE units and PAVE-based units (tetrafluoroethylene and perfluoroethylene Copolymers of Roalkoxyethylene, also referred to as PFA) and polymers containing TFE units and units based on HFP (tetrafluoroethylene-hexafluoropropylene copolymer, also referred to as FEP) are preferred, and PFA and FEP are more preferred, and PFA is more preferred. These polymers may further contain units based on other comonomers.

PAVE is preferably CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ and CF ₂ =CFOCF ₂ CF ₂ CF ₃ (hereinafter also referred to as PPVE), and more preferably PPVE.

The proportion of TFE units in the F polymer is less than 99.5 mol% of all units, and is preferably 90 to 99.0 mol%.

The F polymer preferably has an oxygen-containing polar group. Examples of the oxygen-containing polar group include a hydroxyl group-containing group or a carbonyl group-containing group. From the viewpoint of improving adhesiveness, the oxygen-containing polar group is preferably a carbonyl group-containing group.

The hydroxyl group-containing group is preferably a group containing an alcoholic hydroxyl group, and -CF ₂ CH ₂ OH and -C(CF ₃ ) ₂ OH are more preferable.

Carbonyl group-containing groups include carboxyl group, alkoxycarbonyl group, amide group, isocyanate group, carbamate group (-OC(O)NH ₂ ), acid anhydride residue (-C(O)OC(O)-), and imide residue (- C(O)NHC(O)-, etc.) and carbonate groups (-OC(O)O-) are preferred, and acid anhydride residues are more preferred.

The number of oxygen-containing polar groups in the F polymer is preferably 10 to 5,000, more preferably 100 to 3,000 per 1 x 10 ⁶ carbon atoms in the main chain. In addition, the number of oxygen-containing polar groups in the F polymer can be quantified by the composition of the polymer or the method described in International Publication No. 2020/145133.

The oxygen-containing polar group may be contained in a unit based on a monomer in the F polymer or may be contained in a terminal group of the main chain of the F polymer, with the former being preferred. Examples of the latter embodiment include F polymers having oxygen-containing polar groups as terminal groups derived from polymerization initiators, chain transfer agents, etc., and F polymers obtained by plasma treatment or ionizing radiation treatment of F polymers.

The monomer having a carbonyl group-containing group is preferably itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic anhydride (hereinafter also referred to as NAH), and NAH is more preferable.

The F polymer contains a TFE unit and a PAVE unit, and is preferably a polymer having a carbonyl group-containing group, and includes a TFE unit, a PAVE unit, and a unit based on a monomer having a carbonyl group-containing group, and these units are included for all units. It is more preferable that it is a polymer containing 90 to 99 mol%, 0.99 to 9.97 mol%, and 0.01 to 3 mol% in this order. Specific examples of such F polymer include the polymer described in International Publication No. 2018/16644.

The D50 of the F particles is preferably 0.1 μm or more, more preferably 0.3 μm or more, more preferably more than 0.3 μm, and especially preferably 1 μm or more. The D50 of the F particles is preferably 25 μm or less, more preferably 10 μm or less, and still more preferably 8 μm or less.

The content of F particles in this composition is preferably 3 to 60 mass%, more preferably 5 to 60 mass%, further preferably 10 to 50 mass%, and particularly preferably 12 to 40 mass%.

The content of F particles in this composition may be 3 to 40 mass%, 3 to 20 mass%, or 3 to 16 mass% from the viewpoint of the stretching strength of the formed sheet.

The specific surface area of the F particles is preferably 1 to 25 m ² /g.

One type of F particle may be used, or two or more types may be used.

F particles are particles containing F polymer, and particles made of F polymer are preferable.

The F particles may contain PTFE in addition to the F polymer, and may also contain other resins or inorganic compounds. In addition, PTFE particles and F particles are classified according to the presence or absence of F polymer, and particles containing F polymer are referred to as F particles. For example, particles containing PTFE and F polymer are F particles.

The F particles may form a core-shell structure containing an F polymer in the core and another resin or inorganic compound in the shell, or a core-shell structure containing an F polymer in the shell and another resin or inorganic compound in the core. It may form a shell structure.

Other resins include aromatic polyester, polyamidoimide, polyimide, and polybismaleimide.

Examples of the inorganic compound include the same inorganic substances as those that may be contained in the inorganic particles described later, and among them, silica and boron nitride are preferable.

In this composition, the ratio of PTFE particles to the total of PTFE particles and F particles is preferably 40% by mass or more, and more preferably 45% by mass. The proportion of PTFE particles is preferably 80% by mass or less, and more preferably 70% by mass or less. If the ratio of PTFE particles is within the above range, the composition has excellent uniformity and the generation of aggregates is easily suppressed. Additionally, molded articles formed from this composition tend to have excellent electrical properties. In particular, when the proportion of PTFE particles is 40% by mass or more, the sheet formed from the present composition is likely to have excellent stretching processability. Additionally, if the proportion of PTFE particles is 80% by mass or less, powder fall-off during stretching processing of the sheet formed from the present composition is likely to be suppressed.

The specific liquid compound is not particularly limited as long as it is a liquid compound with a surface tension of less than 72 dyn/cm. The surface tension of a specific liquid compound is preferably 60 dyn/cm or less, and more preferably 40 dyn/cm or less. The surface tension of a specific liquid compound may be 10 dyn/cm or more. In addition, that a liquid compound is in a liquid state means that it is in a liquid state at 25°C.

As a specific liquid compound, a liquid compound that can be removed from the composition by heating, distillation, extraction, etc. is preferable, and a liquid compound with a boiling point of 300°C or lower is more preferable so that it can be easily removed by heating.

In some embodiments, the specific liquid compound preferably contains at least one type selected from the group consisting of hydrocarbons and alcohols. In some embodiments, the specific liquid compound is preferably at least one selected from the group consisting of ethylene glycol, glycerin, and propylene glycol. As a specific liquid compound, propylene glycol is more preferable.

Specific examples of specific liquid compounds include hydrocarbons such as naphtha, white oil, liquid paraffin, toluene, xylene, hexane, n-decane, and dodecane; alcohols such as ethylene glycol, glycerin, and propylene glycol; and polyethylene glycol. One type of liquid compound may be used, or two or more types may be used.

The mass-based content of the specific liquid compound in the first composition is less than the total mass-based content of PTFE particles and F particles, and the content of the specific liquid compound relative to 100 parts by mass of the total content of PTFE particles and F particles is: 98 parts by mass or less is preferable, and 96 parts by mass or less is more preferable. The content of the specific liquid compound is preferably 40 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 80 parts by mass or more.

In addition to the specific liquid compound, the first composition may contain water or another liquid compound with a surface tension of 72 dyn/cm or more. In this case, the proportion of the specific liquid compound in the total content of the specific liquid compound, other liquid compounds, and water is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 99% by mass or more.

The surface tension of the specific liquid compound, other liquid compounds, and water in the first composition is preferably less than 72 dyn/cm, and more preferably satisfies the desired surface tension of the specific liquid compound.

The first composition preferably does not contain other liquid compounds or water.

In the second composition, water and a surfactant are used. The surface tension of the mixture of water and surfactant contained in the second composition is less than 72 dyn/cm. The surface tension of the mixture of water and surfactant is preferably 70 dyn/cm or less, and more preferably 60 dyn/cm or less. The surface tension of the mixture of water and surfactant may be 20 dyn/cm or more.

Surfactants include anionic surfactants, cationic surfactants, and nonionic surfactants. Among these, nonionic surfactants are preferable from the viewpoint that the present composition is excellent in uniformity and the generation of aggregates is easily suppressed. Nonionic surfactants are preferably glycol-based surfactants, acetylene-based surfactants, silicone-based surfactants, or fluorine-based surfactants, and silicone-based surfactants are more preferable. One type of nonionic surfactant may be used, or two or more types may be used. When using two types of nonionic surfactants, it is preferable that the nonionic surfactants are a silicone-based surfactant and a glycol-based surfactant.

Specific examples of nonionic surfactants include the “Ptagent” series (manufactured by Neos), the “Supron (registered trademark)” series (manufactured by AGC Semichemicals), and the “Megapac (registered trademark)” series ( (manufactured by DIC), “Unidyne” series (manufactured by Daikin Kogyo), “BYK-347”, “BYK-349”, “BYK-378”, “BYK-3450”, “BYK-3451”, “BYK- 3455”, “BYK-3456” (manufactured by Big Chemi Japan), “KF-6011”, “KF-6043” (manufactured by Shin-Etsu Chemical Co., Ltd.), “Tergitol” series (manufactured by Dow Chemical Company, “Tergitol TMN-100X” 」etc.).

The content of water based on mass in the second composition is less than the total content based on mass of PTFE particles and F particles, and the content of water relative to 100 parts by mass of the total content of PTFE particles and F particles is preferably 98 parts by mass or less. And, 96 parts by mass or less is more preferable. The water content is preferably 40 parts by mass or more, more preferably 60 parts by mass or more, and still more preferably 80 parts by mass or more.

The content of the surfactant in the second composition is not particularly limited as long as the surface tension of the mixture of water and the surfactant is less than 72 dyn/cm. The content of the surfactant per 100 parts by mass of water in the second composition is preferably 0.1 part by mass or more, and more preferably 1 part by mass or more. The content of the surfactant is preferably 15 parts by mass or less, and more preferably 10 parts by mass or less.

In addition to water, the second composition may contain a specific liquid compound or another liquid compound. In this case, the proportion of water in the total content of water, specific liquid compounds, and other liquid compounds is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 99% by mass or more.

The surface tension of the mixture of water, surfactant, specific liquid compounds, and other liquid compounds in the second composition is preferably less than 72 dyn/cm, and satisfies the preferred surface tension of the mixture of water and surfactant. It is more preferable to be

The second composition preferably does not contain specific liquid compounds or other liquid compounds.

This composition may contain inorganic particles.

Since the composition contains a specific liquid compound, or contains water and a surfactant, and the surface tension of the mixture of water and surfactant is less than 72 dyn/cm, the wettability of the F particles increases and the agglomeration of the F particles is loosened. easy. Then, the coalescence of the inorganic particles and the F particles is promoted, and particles that can be considered composite particles of both particles are formed. As a result, since the inorganic particles and F particles are uniformly mixed, it is inferred that this composition is likely to have excellent dispersibility. Additionally, it is inferred that this composition yields a molded article in which aggregation of inorganic particles or F particles is suppressed and the components are uniformly distributed. Additionally, it is estimated that falling off of inorganic particles becomes less likely to occur.

The shape of the inorganic particles is preferably spherical, scaly, layered, needle-like or plate-shaped, more preferably spherical, scaly or lamellar, and even more preferably spherical or scaly.

It is preferable that the spherical inorganic particles are substantially spherical. A roughly spherical shape means that the ratio of the minor axis to the major axis is 0.7 or more when the inorganic particle is observed with a scanning electron microscope (SEM). The proportion of approximately spherical inorganic particles is preferably 95% or more of the total number of inorganic particles.

The aspect ratio of the non-spherical inorganic particles is preferably 2 or more, and is preferably 5 or more. The aspect ratio is preferably 10000 or less.

The inorganic particles may be hollow. In this case, the molded product obtained by molding the present composition is likely to have excellent electrical properties.

The inorganic particles are particles containing at least one type of inorganic substance, preferably particles containing at least one type selected from the group consisting of carbon, metal oxide, silica, and nitride, and the group consisting of silica, boron nitride, and titanium dioxide. Particles containing at least one type selected from are more preferable.

Specific examples of inorganic substances include graphite, hard carbon, soft carbon, mesoporous carbon, carbon such as graphene, boron nitride, aluminum nitride, beryllia, silica, wollastonite, talc, steatite, cerium oxide, and aluminum oxide. , magnesium oxide, zinc oxide, barium titanate, lead zirconate titanate, lead titanate, zirconium oxide, and titanium oxide.

Additionally, specific examples of inorganic substances include lithium-based oxides such as lithium nickel manganese cobalt oxide, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium cobalt oxide, and lithium nickel cobalt aluminum oxide.

The inorganic particles are preferably particles containing silica or boron nitride from the viewpoint of lowering the dielectric constant and dielectric loss tangent of the molded product and improving low linear expansion properties. The silica is preferably amorphous silica. Boron nitride is preferably hexagonal boron nitride.

Additionally, from the viewpoint of improving the dielectric constant, the inorganic particles are preferably particles containing titanium dioxide or barium titanate.

When the inorganic particles contain silica, it is preferable that the inorganic particles are hollow silica from the viewpoint of the electrical properties of the molded product.

When the inorganic particles contain nitride, from the viewpoint of the electrical properties of the molded product and low linear expansion, the inorganic particles preferably contain boron nitride or aluminum nitride, and are more preferably flaky boron nitride or pillar-shaped aluminum nitride. The flaky boron nitride may be aggregated to form secondary particles.

The D50 of the inorganic particles is preferably 20 μm or less, and more preferably 10 μm or less. The D50 of the inorganic particles is preferably 0.01 μm or more, and more preferably 0.1 μm or more.

The specific surface area of the inorganic particles is preferably 1 to 20 m ² /g.

The content of the inorganic particles in this composition is preferably 15% by mass or more, more preferably 20 to 80% by mass, and even more preferably 40 to 70% by mass, based on the total amount of the composition.

The surface of the inorganic particle may be surface treated with a silane coupling agent. In this case, the affinity between the inorganic particles and the PTFE and F polymers is improved, so that the inorganic particles are easily dispersed uniformly in the composition and the molded article, and the inorganic particles are difficult to peel from the molded article. In addition, the molded product tends to have excellent electrical properties and low linear expansion properties.

Silane coupling agents include 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxy. A silane coupling agent having a functional group such as silane or 3-isocyanate propyltriethoxysilane is preferable.

Specific examples of particles containing silica include the “Adma Fine” series (manufactured by Admatex Corporation), the “SFP” series (manufactured by Denka Corporation), and the “E-SPHERES” series (manufactured by Taiheiyo Cement Corporation). Examples include the “Sirinax” series (manufactured by Nittetsu Mining Co., Ltd.), the “Ecosphere” series (manufactured by Emerson & Kaming Co., Ltd.), and the “hydrophobic AEROSIL” series (“RX200”, etc.) (manufactured by Japan Aerosil Co., Ltd.). You can.

Specific examples of particles containing zinc oxide include the “FINEX” series (manufactured by Sakai Chemical Industry Co., Ltd.).

Specific examples of particles containing titanium oxide include the “Typake (registered trademark)” series (manufactured by Ishihara Sangyo Corporation) and the “JMT” series (manufactured by Teika Corporation).

Specific examples of particles containing talc include the “SG” series (manufactured by Nippon Talc Co., Ltd.).

Specific examples of particles containing steatite include the “BST” series (manufactured by Nippon Talc Co., Ltd.).

Specific examples of particles containing boron nitride include the “UHP” series (manufactured by Showa Denko) and the “GP” and “HGP” grades of the “Dencarboron Nitride” series (manufactured by Denka Corporation). .

One type of inorganic particle may be used, or two or more types may be used. For example, as the inorganic particles, silica particles, boron nitride particles, and titanium dioxide particles may be used in combination. In this case, the respective contents of silica particles, boron nitride particles, and titanium dioxide particles in the total amount of inorganic particles are preferably 10 to 60% by mass, 10 to 60% by mass, and 5 to 40% by mass in this order. .

This composition may contain an aromatic polymer or its precursor (hereinafter also referred to collectively as AR polymer). AR polymer may be thermosetting or thermoplastic.

Examples of the AR polymer include aromatic polyimide, aromatic polyimide precursor which is polyamic acid or its salt, aromatic polyamidoimide, aromatic polyamidoimide precursor, aromatic polyetherimide, aromatic polyetherimide precursor, aromatic polyimide, polyamic acid, and aromatic polyimide precursor. An aromatic polyimide precursor that is a mixed acid or a salt thereof, aromatic polyamidoimide, or an aromatic polyamidoimide precursor is more preferable.

The content of the AR polymer in this composition is preferably 0.1 to 20 parts by mass, and more preferably 1 to 10 parts by mass, based on a total of 100 parts by mass of the PTFE particles and F particles.

Specific examples of AR polymer include the “Upia AT” series (manufactured by Ube Kosan Corporation), the “Neoprim (registered trademark)” series (manufactured by Mitsubishi Gas Chemical Corporation), and the “Speakeria (registered trademark)” series (manufactured by Somal Corporation). , “Q-PILON (registered trademark)” series (manufactured by PI Technology Research Institute), “WINGO” series (manufactured by Wingo Technology), “Tomide (registered trademark)” series (manufactured by T&K TOKA), “KPI-MX ” series (manufactured by Kawamura Sangyo Co., Ltd.), “HPC-1000”, and “HPC-2100D” (all manufactured by Showa Denko Materials Co., Ltd.).

In this composition, the AR polymer may be particulate or non-particulate, and is preferably non-particulate. In this composition, the AR polymer is preferably dissolved in a specific liquid compound or water. The AR polymer may be bonded to PTFE particles, F particles, or inorganic particles.

This composition also contains organic substances such as pH adjusters, pH buffers, organic particles, organic pigments, metallic soaps, lubricants, organic monomers, organic oligomers with a degree of polymerization of 50 or less, thixotropic imparting agents, viscosity modifiers, anti-foaming agents, silane coupling agents, Other ingredients such as dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, brighteners, colorants, conductive agents, mold release agents, surface treatment agents, and flame retardants may be included.

This composition is a mass or clay in which the PTFE particles and F particles are adhered but the shape of the particles is maintained, or the PTFE particles and F particles are adhered and the particle shape is not maintained. It may be a composition of the same phase.

The method for producing this composition is not particularly limited.

It is preferable that this composition is a kneaded product. That is, the present composition is preferably a composition obtained by mixing PTFE particles, F particles, and a specific liquid compound or water.

The first composition is preferably obtained by mixing PTFE particles, F particles, and a specific liquid compound. Additionally, when kneading PTFE particles, F particles, and a specific liquid compound, other components such as inorganic particles and AR polymer may be added.

In the method for producing the first composition, when mixing PTFE particles, F particles, liquid compounds, and other components used as needed, the PTFE particles, F particles, liquid compounds, and other components used as needed are lumped together. A method of kneading while sequentially adding PTFE particles, F particles, liquid compounds, and other components used as needed can be mentioned.

The second composition is preferably obtained by mixing PTFE particles, F particles, water, and a surfactant. Additionally, when kneading the PTFE particles, F particles, water, and surfactant, other components such as inorganic particles and AR polymer may be added.

In the method for producing the second composition, when mixing the PTFE particles, F particles, water, surfactant, and other components used as needed, the PTFE particles, F particles, water, surfactant, and other components used as needed are mixed. Examples include a method of mixing the external components all at once, and a method of mixing while sequentially adding PTFE particles, F particles, water, surfactant, and other components used as needed. When preparing the second composition, water and the surfactant may be added individually or as a mixture of water and the surfactant.

A specific method of kneading includes, for example, a method of adding PTFE particles and F particles in batches to a specific liquid compound, or a mixture of water and a surfactant, and kneading: to a specific liquid compound, or a mixture of water and a surfactant. , Method of kneading PTFE particles and F particles while sequentially adding them: Pre-mixing PTFE particles and F particles in a powder state, and kneading the obtained pre-mixture with a specific liquid compound or a mixture of water and surfactant in advance: Examples include a method of individually kneading PTFE particles and a mixture of a specific liquid compound or a mixture of water and a surfactant, and F particles and a mixture of a specific liquid compound or water and a surfactant, and further kneading the two types of mixture obtained. You can.

When mixing the components constituting the composition while sequentially adding them, the order of addition of each component is not particularly limited. It is preferred that the PTFE particles and F particles are premixed prior to adding the specific liquid compound or mixture of water and surfactant. In addition, when the composition contains inorganic particles as other components, the F particles and the inorganic particles are mixed, and then PTFE particles are added and mixed to obtain a powder composition, and then a liquid compound or a mixture of water and a surfactant is added. It is more preferable to add it to the powder composition and knead it.

This composition containing carbon or lithium-based oxide is preferably prepared from a powder composition obtained by mixing carbon or lithium-based oxide and F particles, and then adding and mixing PTFE particles. When mixing PTFE particles, it is desirable to apply a strong shear force to promote fibrillation of PTFE. Additionally, after adding and mixing PTFE particles, carbon or lithium-based oxide may be further added and mixed. Either carbon or lithium-based oxide may be used, or both carbon and lithium-based oxide may be used.

A molded product formed from such a powder composition maintains a strong and homogeneous carbon or lithium-based oxide, and is particularly useful as an electrode member for lithium ion capacitors or lithium secondary batteries, such as a cathode electrode film.

During kneading, it is preferable to knead so that the mass of the composition does not substantially change, and it is preferable to knead in a closed system. That is, it is preferable to knead so that specific liquid compounds or water in the composition do not evaporate during kneading. As a result, each component is uniformly mixed and a highly defoamed composition is obtained.

At the time of kneading, it is preferable to use a kneader equipped with a stirring tank and single-axis or multi-axis stirring blades. The number of stirring blades is preferably two or more to obtain a high kneading effect. The kneading method may be either batch or continuous.

The kneader used for batch kneading is preferably a Henschel mixer, a pressure kneader, a Banbury mixer, a planetary mixer, a colloid mill, a rotating/revolving stirrer, or a thin film rotating type stirrer, and a planetary mixer or a rotating/revolving stirrer is more preferable. The planetary mixer has a two-axis stirring blade that rotates and rotates with respect to each other, and has a structure that stirs and kneads the kneaded product in the stirring tank. Therefore, the dead space in the stirring tank that the stirring blade does not reach is small, the load on the blade is reduced, and the composition can be kneaded to a high degree.

The rotation and revolution stirrer has a structure that stirs and kneads the kneaded product within a tank provided with a stirring mechanism by rotation and revolution. Here, the stirring mechanism by rotation is a mechanism that stirs and kneads the kneaded material by rotating the tank containing the kneaded material around the rotation axis. The direction of the rotation axis may be any direction with respect to the jaw. On the other hand, the rotational stirring mechanism is a mechanism that stirs and kneads the kneaded material by rotating the tank around an apex outside the tank containing the kneaded material. The axis of rotation of the jaw with respect to the orbital plane may be vertical, horizontal, or inclined.

According to the planetary mixer or the rotating and revolving stirrer, the PTFE particles and F particles are wetted with a specific liquid compound or a mixture of water and a surfactant while suppressing agglomeration of the PTFE particles and F particles, and the PTFE particles and F particles are highly agitated. They can be mixed while interacting.

Kneading may be performed while cooling or may be performed while heating. When heated, the composition becomes viscous, so a load is applied to the stirring blade of the kneader, and as a result, the shear force on the PTFE and F polymers tends to increase. In particular, when a plurality of stirring blades are used, shearing force is likely to be applied to the F polymer between the stirring blades or between the stirring blades and the stirring tank. As a result, when inorganic particles are added, not only are the PTFE particles, F particles, and inorganic particles sufficiently mixed, but also the disintegration of the PTFE particles, F particles, or inorganic particles progresses, and the present composition with excellent dispersibility is likely to be formed. .

By kneading, the PTFE particles may be fibrillated. In a molded article formed from the present composition in which PTFE particles are fibrillated, PTFE easily supports F particles or inorganic particles, and it is difficult for the F particles or inorganic particles to be peeled off from the molded article. Additionally, PTFE becomes easily entangled with F polymer or inorganic particles, and the toughness of the molded product tends to improve.

The first method for producing a composition of the present disclosure is a method of obtaining a composition by kneading PTFE particles, F particles, and a specific liquid compound. Additionally, in the composition, the mass-based content of the specific liquid compound is less than the total mass-based content of the PTFE particles and F particles.

The second manufacturing method of the composition of the present disclosure is a method of obtaining a composition by mixing PTFE particles, F particles, water, and a surfactant. Additionally, in the composition, the mass-based content of water is less than the total mass-based content of PTFE particles and F particles. Additionally, the surface tension of the mixture of water and surfactant is less than 72 dyn/cm.

Hereinafter, the first manufacturing method and the second manufacturing method are collectively referred to as this method.

The details of PTFE particles, F particles, specific liquid compounds, water, and surfactant in this method are as described above for this composition.

The details of the kneading method in this method are as described above in the method for producing this composition.

In this method, the composition may further contain other components such as inorganic particles and AR polymer. Details of other components are as described above in the present composition, and the mixing method is also as described above in the present composition.

The method for producing a sheet of the present disclosure is a method of obtaining a sheet by molding the present composition. Hereinafter, the sheet obtained by molding the present composition is also referred to as the present sheet. Methods for molding this composition include a method of softening the composition. By softening the composition, PTFE is fibrillated, PTFE easily supports F particles, and it is easy to obtain a sheet in which F particles are unlikely to peel off. Additionally, when the composition contains inorganic particles, it is easy to obtain a sheet in which the inorganic particles are unlikely to peel off. Additionally, it is easy to obtain this sheet with excellent electrical properties and toughness.

Methods for softening the composition include press molding, extrusion molding, or calendar molding. In addition, calender molding refers to a method of rolling the composition by passing it between a plurality of rolls.

In the present disclosure, the sheet may be obtained by removing the liquid compound or water from the composition and then molding the composition.

Casting of this composition may be performed using one type of molding method, or may be performed by combining two or more molding methods. In addition, casting may be performed by repeating one type of molding method multiple times. For example, the mother sheet obtained by extrusion molding the present composition may be further softened by calender molding, or the mother sheet obtained by calender molding the composition may be further softened by calender molding. In this case, it is easy to obtain a sheet of arbitrary thickness that is excellent in toughness and uniformity.

A plurality of rolls in calender molding may be used, and it is preferable to use a combination of four. Arrangement methods of the four rolls include I-type, S-type, inverted L-type, Z-type, and square Z-type.

Casting of this composition may be carried out while heating at a temperature below the melting temperature of PTFE, or may be carried out without heating. After casting, the composition may be heated to remove specific liquid compounds or water.

As described above, this sheet is obtained. The thickness of this sheet is, for example, 0.5 to 5 mm.

This sheet may be obtained by heating and baking above the melting temperature of PTFE.

When two or more of the sheets obtained above are stacked, a laminated sheet is obtained. A laminated sheet is obtained, for example, by overlapping two or more main sheets and rolling them. The number of layers of the laminated sheet is, for example, about 2 to 10 layers. From the viewpoint of strength between stacks, it is preferable to roll the sheets by overlapping them one by one.

Additionally, the sheets may be folded and stacked. By folding, stacking, and rolling this sheet, the sheet strength is improved and, when the present composition contains inorganic particles, the inorganic particles can be firmly fixed to the PTFE matrix. As a result, a laminated sheet with a high mixing ratio of inorganic particles and flexibility can be produced.

A plurality of laminated sheets may be overlapped to form a laminated sheet with a larger number of laminated sheets.

When manufacturing a laminated sheet, it is desirable to change the rolling direction. For example, when rolling a second main sheet on top of a first main sheet and then rolling a third main sheet to obtain a laminated sheet, the direction in which the third main sheet is rolled is set to the direction in which the second main sheet is stacked. It is desirable to change the rolling direction by 90 degrees. By rolling while changing the direction in this way, the PTFE network extends longitudinally and horizontally, thereby improving the strength of the sheet and, when the composition contains inorganic particles, firm fixation of the inorganic particles to the PTFE matrix.

The obtained laminated sheet may be pressure molded. By pressure molding, pores in the laminated sheet can be reduced.

When this sheet or the laminated sheet obtained above is heat-compressed with a base material, a laminate having a base material layer and a polymer layer containing PTFE, F polymer, and inorganic particles or AR polymer used as necessary is obtained.

As a base material, metal substrates such as metal foils such as copper, nickel, aluminum, titanium, and alloys thereof, polyimide, polyamide, polyetheramide, polyphenylene sulfide, polyallyl ether ketone, polyamideimide, and liquid crystalline polyester. and heat-resistant resin films such as tetrafluoroethylene-based polymers, prepreg substrates that are precursors of fiber-reinforced resin substrates, ceramic substrates such as silicon carbide, aluminum nitride, or silicon nitride, and glass substrates.

The shape of the base material includes planar shape, curved shape, and uneven shape. Additionally, the shape of the base material may be any of thin, plate, film, or fibrous shapes.

The 10-point average roughness of the surface of the substrate is preferably 0.01 to 0.05 μm.

The surface of the substrate may be surface treated with a silane coupling agent or may be plasma treated. Specific examples of the silane coupling agent are as described above.

Methods of thermal compression include applying pressure between the base material and the main sheet or laminated sheet with a pair of opposing hot plates, passing the base material and the main sheet or laminated sheet between a pair of opposing rolls, A method of applying pressure to the base material and the main sheet or laminated sheet using a roll on a hot plate can be used.

The temperature of thermocompression is preferably 200°C or higher, more preferably higher than the melting temperature of PTFE, and even more preferably 340°C or higher. The temperature for thermocompression is preferably 400°C or lower. It is preferable to bake PTFE by heating during thermocompression. Heat compression may be performed using a hydraulic press.

The pressure of thermocompression is preferably 1 to 40 MPa, and more preferably 10 to 30 MPa.

Thermocompression may be performed under reduced pressure. In this case, it is preferable to carry out the vacuum degree of 20 kPa or less from the viewpoint of suppressing deterioration of the base material and the main sheet due to oxidation. In this case, it is preferable to perform thermocompression using a vacuum press.

During heat compression, from the viewpoint of suppressing adhesion of the sheet to the hot plate or roll, it is recommended to place a release film between the surface of the sheet and the hot plate or roll, or to surface treat the surface of the hot plate or roll with a release agent. desirable.

The thickness of the release film is preferably 50 to 150 μm.

Release films include polyimide films, and specific examples include "Apical NPI" (manufactured by Kaneka Corporation), "Kafton EN" (Toray DuPont Corporation), and "Upirex S" (Ube Industries). can be mentioned.

This sheet or laminated sheet may be heat-compressed only on one surface of the base material, or may be heat-compressed on both surfaces of the base material. In the former case, a laminate having a base material layer and a polymer layer on one surface of the base layer is obtained, and in the latter case, a laminate having a base layer and a polymer layer on both surfaces of the base layer is obtained. Lose.

Preferred specific examples of the laminate include a metal foil and a metal-clad laminate having a polymer layer on at least one surface of the metal foil, a polyimide film, and a multilayer film having a polymer layer on both surfaces of the polyimide film. I can hear it.

The peeling strength between the polymer layer and the base material layer is preferably 10 to 100 N/cm.

Additionally, the base layer may be removed from the laminate to obtain a sheet containing PTFE and F polymer.

Molded products such as this sheet, laminated sheet, and laminate having laminated sheets are useful as antenna parts, printed boards, aircraft parts, automobile parts, sports equipment, food industry products, heat dissipation parts, paints, cosmetics, etc.

Specifically, electric wire covering materials such as aircraft wires, enamel wire covering materials used in motors such as electric vehicles, electrical insulating tape, insulating tape for oil drilling, petroleum transport hoses, hydrogen tanks, materials for printed circuit boards, microfiltration membranes, ultraviolet rays. Separation membranes such as filtration membranes, reverse osmosis membranes, ion exchange membranes, dialysis membranes and gas separation membranes, lithium ion capacitors, electrode binders for lithium ion secondary batteries and fuel cells, copy rolls, covers and sliding members for furniture, car dashboards, home appliances, etc. , tension ropes, wear pads, wear strips, tube lamps, test sockets, wafer guides, wear parts of centrifugal pumps, chemical and water supply pumps, tools such as shovels, files, awls and saws, boilers, hoppers, pipes, ovens, Baking pans, chutes, racket guts, dies, toilets, container coverings, power devices, transistors, thyristors, rectifiers, transformers, power MOS FETs, CPUs, heat dissipation fins, metal heat sinks, blades of windmills, wind power generation facilities, aircraft, etc., Casings for personal computers and displays, electronic device materials, interior and exterior of automobiles, sealing materials for processing machines, vacuum ovens, and plasma processing devices that perform heat processing under low oxygen, heat dissipation components within processing units such as sputtering and various dry etching devices, and electromagnetic waves. Useful as a shield. Sliding members include load bearings, yaw bearings, sliding shafts, valves, bearings, bushes, seals, thrust washers, wear rings, pistons, slide switches, gears, cams, belt conveyors, and food transport belts.

Although the present method, the method for producing the present sheet, and the method for producing the laminated sheet and the laminated body have been described above, the present disclosure is not limited to the configuration of the above-described embodiment.

For example, the present method, the present sheet manufacturing method, and the laminated sheet and laminate manufacturing method may further include any other process in the configuration of the above embodiment, and any process that produces the same effect may be used. It may be substituted with .

Example

Next, embodiments of the present disclosure will be specifically described using examples, but the embodiments of the present disclosure are not limited to these examples.

1. Preparation of each ingredient

[PTFE particles]

PTFE particle 1: Particles of PTFE containing 99.9 mol% or more of TFE units (D50: 0.3 ㎛)

[F particles]

F particle 1: Tetrafluoroethylene containing 97.9 mol%, 0.1 mol%, and 2.0 mol% of TFE units, NAH units, and PPVE units in this order, and having 1000 carbonyl group-containing groups per 1 × 10 ⁶ carbon number in the main chain. Particles (D50: 2.1 ㎛) of polymer (melting temperature: 300 ℃)

[Liquid compound]

Liquid compound 1: propylene glycol (surface tension: 35 dyn/cm)

Liquid compound 2: Naphtha (surface tension: 20 dyn/cm)

[Inorganic particles]

Inorganic particle 1: spherical silica (D50: 1 ㎛)

[Surfactants]

Surfactant 1: Silicone-based surfactant

2. Preparation of the composition

[Example 1]

F particles 1 and inorganic particles 1 were added to the mixer and mixed. Additionally, PTFE particles 1 were added and mixed to obtain a powder composition.

The obtained powder composition and liquid compound 1 were put into a rotating and revolving stirrer, and kneaded while defoaming at a rotating speed of 800 rpm and a rotating speed of 2000 rpm, and 20 parts by mass of PTFE particles 1, 20 parts by mass of F particles 1, and 60 parts by mass were mixed. Composition 1, which is a clay-like kneaded product containing 38 parts by mass of inorganic particles 1 and 38 parts by mass of liquid compound 1, was obtained.

[Example 2]

Composition 2 was obtained in the same manner as in Example 1 except that liquid compound 1 was changed to liquid compound 2.

[Example 3]

Composition 3 was obtained in the same manner as in Example 1, except that 38 parts by mass of liquid compound 1 were replaced with 37 parts by mass of water and 1 part by mass of surfactant 1. Additionally, the surface tension of water was 72 dyn/cm, and the surface tension of a mixture of 37 parts by mass of water and 1 part by mass of surfactant 1 was less than 72 dyn/cm.

[Example 4]

Composition 4 was obtained in the same manner as in Example 1 except that liquid compound 1 was changed to water.

[Example 5]

Composition 5 was obtained in the same manner as in Example 1 except that the amount of PTFE particles 1 was 35 parts by mass and the amount of F particles 1 was 5 parts by mass.

[Example 6]

Composition 6 was obtained in the same manner as in Example 1 except that the amount of PTFE particles 1 was 15 parts by mass and the amount of F particles 1 was 25 parts by mass.

Additionally, the proportion of PTFE particles 1 in the total of PTFE particles 1 and F particles 1 is 50% by mass in Compositions 1 to 4, 88% by mass in Composition 5, and 38% by mass in Composition 6.

3. Manufacturing of sheets

Composition 1 was passed between a pair of rolling rolls to soften it, and mother sheet 1 with a thickness of 3 mm was obtained. The mother sheet 1 was softened using an inverted L-shaped calender, and further heated in an oven at 150°C for 30 minutes to remove the liquid compound 1, thereby obtaining sheet 1 with a thickness of 200 μm.

Sheets 2 to 6 were obtained in the same manner from compositions 2 to 6.

When sheets 1, 2, 3, 5, and 6 were manufactured, contamination of the oven due to powder dropping was not confirmed. When manufacturing Sheet 4, contamination of the oven due to falling powder was confirmed.

Additionally, as a result of visual inspection of the surfaces of each sheet, no aggregates were visually observed on the surfaces of sheets 1 and 6. In sheets 2, 3, and 5, aggregates were observed on only a small portion of the surface. In sheet 4, aggregates were recognized throughout the surface.

Additionally, when sheets 1, 5, and 6 were subjected to stretching treatment, sheets 1 and 5 had stretching strengths of 200% or more, while the stretching strength of sheet 6 was low. Also, during the stretching treatment, no peeling occurred from sheet 1, but peeling did occur from sheet 5.

The disclosures of Japanese Patent Application No. 2021-160035 and Japanese Patent Application No. 2021-193618 are hereby incorporated by reference in their entirety.

All documents, patent applications, and technical standards described in this specification are hereby incorporated by reference to the same extent as if each individual document, patent application, or technical standard were specifically and individually indicated to be incorporated by reference. It is taken in.

Claims (15)

A composition comprising particles containing polytetrafluoroethylene and particles containing a heat-meltable tetrafluoroethylene polymer, and satisfying any of the following (1) or (2).
(1) It further contains a liquid compound having a surface tension of less than 72 dyn/cm, and the total content based on the mass of the particles containing the polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene polymer. The mass-based content of the liquid compound is lower than that of the liquid compound.
(2) It further contains water and a surfactant, and has a content based on the mass of the water greater than the total content based on the mass of the particles containing the polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene-based polymer. The content is small, and the surface tension of the mixture of water and the surfactant is less than 72 dyn/cm. According to claim 1,
A composition that satisfies the above (1) and wherein the liquid compound contains at least one member selected from the group consisting of hydrocarbons and alcohols. According to claim 2,
A composition in which the alcohol contains at least one selected from the group consisting of ethylene glycol, glycerin, and propylene glycol. According to claim 1,
A composition wherein the heat-meltable tetrafluoroethylene-based polymer has a melting temperature of 200 to 320°C. According to claim 1,
A composition wherein the heat-meltable tetrafluoroethylene polymer has an oxygen-containing polar group. According to claim 1,
A composition wherein the ratio of the particles containing the polytetrafluoroethylene to the total of the particles containing the polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene polymer is 40 to 80% by mass. . According to claim 4,
A composition wherein the ratio of the particles containing the polytetrafluoroethylene to the total of the particles containing the polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene polymer is 40 to 80% by mass. . According to claim 5,
A composition wherein the ratio of the particles containing the polytetrafluoroethylene to the total of the particles containing the polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene polymer is 40 to 80% by mass. . The method according to any one of claims 1 to 8,
A composition further comprising inorganic particles. According to clause 9,
A composition wherein the content of the inorganic particles is 15% by mass or more based on the total amount of the composition. The method according to any one of claims 1 to 8,
A composition further comprising an aromatic polymer or a precursor thereof. According to claim 10,
A composition further comprising an aromatic polymer or a precursor thereof. The method according to any one of claims 1 to 8,
A composition that is a mixture. A method for producing a composition containing particles containing polytetrafluoroethylene and particles containing a heat-meltable tetrafluoroethylene polymer, which satisfies the following (A) or (B).
(A) A liquid compound having a surface tension of less than 72 dyn/cm is added to the composition and kneaded, and the mass of the particles containing the polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene polymer A composition is obtained in which the mass-based content of the liquid compound is lower than the standard total content.
(B) Water and a surfactant are added to the composition and kneaded, and the total content based on the mass of the particles containing the polytetrafluoroethylene and the particles containing the heat-meltable tetrafluoroethylene polymer is higher than the above. A composition is obtained in which the content of water by mass is low and the surface tension of the mixture of water and the surfactant is less than 72 dyn/cm. A method for producing a sheet, comprising forming the composition according to any one of claims 1 to 8 to obtain a sheet.