TW202400689A - Dispersion liquid - Google Patents

Abstract

The present invention provides a dispersion liquid which contains a tetrafluoroethylene-based polymer and has excellent dispersion stability and handling properties, and which enables the achievement of a molded product that has excellent physical properties such as heat resistance and electrical characteristics (low linear expansion coefficient, low dielectric constant and low dielectric loss tangent), in particular, an excellent surface appearance. This dispersion liquid contains particles of a tetrafluoroethylene-based polymer, a nonionic surfactant, a cellulose ether that has a degree of substitution of 1.4 or more, and water.

Description

Dispersions

The present invention relates to a dispersion liquid containing particles of a tetrafluoroethylene polymer.

In recent years, in order to cope with the increase in speed and frequency of mobile communication equipment such as mobile phones, materials with low dielectric constant and low dielectric tangent are required for the insulating layer of the printed circuit board of the communication equipment. Therefore, tetrafluoroethylene polymers have attracted much attention. Attention. As a material for forming an insulating layer containing this polymer, a dispersion liquid containing particles of a tetrafluoroethylene-based polymer and a liquid dispersion medium is known. Patent Document 1 proposes an aqueous dispersion that contains a predetermined amount of polytetrafluoroethylene with a dispersed volume average particle size of 1 to 50 μm and a water-soluble thickener. Patent Document 2 proposes an aqueous dispersion liquid containing particles of a tetrafluoroethylene-based polymer in a specific particle size range, a non-alkyl phenol-type nonionic surfactant, and a specific acetylene glycol-based surfactant. Prior technical literature patent documents

Patent Document 1: Japanese Patent Application Publication No. 2019-052211 Patent Document 2: International Publication No. 2022/054762

The problem to be solved by the invention The aqueous dispersion requires a wide range of equipment for use and a high selectivity of substrates to be coated. However, since the surface tension of the tetrafluoroethylene polymer is low, the dispersibility of its particles in water is low, and the dispersion tends to foam, making it difficult to handle the fluidity of the aqueous dispersion when used for coating, etc. That's enough. When particles of a tetrafluoroethylene-based polymer with an average particle diameter of 1 μm or more are used as in Patent Document 1 and the content of the particles in the aqueous dispersion increases, the above-mentioned problems are likely to become significant. In addition, defects may easily occur on the surface of a molded object such as a polymer layer formed from the aqueous dispersion, which may easily damage the surface appearance. Furthermore, the aqueous dispersion proposed in Patent Document 2 also has room for improvement in its handling properties such as suppressing foaming.

The present inventors found that a dispersion liquid containing a tetrafluoroethylene-based polymer, a specific cellulose ether, a nonionic surfactant, and water can suppress the formation of coarse particles and have excellent dispersion stability, and can suppress foaming and is easy to handle. . It was also found that the molded article such as the polymer layer formed from the dispersion liquid has heat resistance, electrical characteristics (low linear expansion coefficient, low dielectric constant and low dielectric tangent) due to the tetrafluoroethylene polymer. The present invention is achieved by excellent physical properties, especially excellent surface appearance. The object of the present invention is to provide a dispersion liquid containing a tetrafluoroethylene-based polymer, which has excellent dispersion stability and handleability, and can develop heat resistance and electrical properties (low linear expansion coefficient, low dielectric constant and low dielectric tangent). Molded products with excellent physical properties, especially excellent surface appearance.

Means for Solving the Problems The present invention has the following aspects. [1] A dispersion liquid containing: particles of a tetrafluoroethylene polymer, a nonionic surfactant, a cellulose ether with a degree of substitution of 1.4 or more, and water. [2] The dispersion liquid of [1], wherein the average particle diameter of the particles of the tetrafluoroethylene-based polymer is 1 μm or more and less than 10 μm, and the specific surface area is 1 to 25 m ² /g. [3] The dispersion liquid according to [1] or [2], wherein the content of the particles of the tetrafluoroethylene-based polymer is greater than 30% by mass. [4] The dispersion liquid according to any one of [1] to [3], wherein the tetrafluoroethylene polymer is a tetrafluoroethylene polymer having a carbonyl group-containing group. [5] The dispersion liquid according to any one of [1] to [4], which has 100 to 3000 of the above-mentioned carbon atoms per 1×10 ⁶ main chain carbon number of the tetrafluoroethylene polymer. Groups containing carbonyl groups. [6] The dispersion liquid according to any one of [1] to [5], which contains an alcohol-based surfactant with an HLB value of less than 10 as the nonionic surfactant. [7] The dispersion liquid according to any one of [1] to [6], which contains a nonionic surfactant with an HLB value of 10 or more as the nonionic surfactant. [8] The dispersion liquid according to any one of [1] to [7], which contains an alcohol-based surfactant with an HLB value of less than 10 and a polysiloxane-based surfactant with an HLB value of 10 or more as the above-mentioned nonionic Surfactants. [9] The dispersion liquid according to any one of [1] to [8], wherein the content of the nonionic surfactant is 1 to 15% by mass relative to the content of the particles. [10] The dispersion liquid according to any one of [1] to [9], wherein the degree of substitution of the cellulose ether is 1.9 to 2.9. [11] The dispersion liquid according to any one of [1] to [10], wherein the cellulose ether is carboxyalkyl cellulose, hydroxyalkyl cellulose or hydroxyalkyl alkyl cellulose. [12] The dispersion liquid according to any one of [1] to [11], wherein the cellulose ether is hydroxyalkyl cellulose or hydroxyalkyl alkyl cellulose. [13] The dispersion liquid according to any one of [1] to [12], which further contains monoalcohol having 1 to 6 carbon atoms. [14] The dispersion liquid according to any one of [1] to [13], further containing at least one selected from the group consisting of aromatic polymers and inorganic fillers. [15] A method for manufacturing a laminated body, which is obtained by arranging the dispersion liquid according to any one of [1] to [14] on the surface of a base material and heating it to form a polymer layer containing the above-mentioned tetrafluoroethylene polymer. A laminate including a base material layer composed of the above-mentioned base material and the above-mentioned polymer layer in this order.

Invention effect According to the present invention, a dispersion liquid excellent in dispersion stability and handling properties can be provided. The dispersion can form a molded article such as a coating film (polymer layer) based on the heat resistance and electrical properties (low linear expansion coefficient, low dielectric constant and low dielectric constant) due to the tetrafluoroethylene polymer. tangent) and other physical properties, especially its surface appearance.

The following terms have the following meanings. "Average particle size (D50)" is the volume-based cumulative 50% particle size of particles or fillers determined by the laser diffraction and scattering method. That is, the particle size distribution is measured by the laser diffraction scattering method, and a cumulative curve is obtained by setting the total volume of the particle group to 100%, and then the particle diameter is the point at which the cumulative volume becomes 50% on the cumulative curve. The D50 of particles or fillers can be obtained by dispersing the particles in water and measuring laser diffraction using a laser diffraction scattering particle size distribution measuring device (LA-920 measuring instrument, manufactured by Horiba Manufacturing Co., Ltd.) Obtained by scattering analysis. "Average particle size (D90)" is the volume-based cumulative 90% particle size of particles calculated in the same manner as D50. The specific surface area of the particles or filler is a value calculated by measuring the particles by the gas adsorption (constant volume method) BET multi-point method, and it is obtained using NOVA4200e (manufactured by Quantachrome Instruments). "Melting temperature" refers to the temperature corresponding to the maximum value of the melting peak of a polymer measured by differential scanning calorimetry (DSC). "Glass transition point (Tg)" refers to the value determined by analyzing a polymer using dynamic viscoelasticity (DMA). "Viscosity" is determined by measuring the dispersion using a B-type viscometer at 25°C and a rotation speed of 30 rpm. After repeating the measurement three times, take the average of the three measured values. The so-called "thixotropy ratio" refers to the value calculated by dividing the viscosity eta ₁ of the dispersion measured at a rotation speed of 30 rpm by the viscosity eta ₂ measured at a rotation speed of 60 rpm. The measurement of each viscosity was repeated three times, and the average of the three measured values was taken. The "surface tension" of a solvent or solution is a value measured by the Wilhelmy method at 25°C using a surface tensiometer. The "HLB (Hydrophilic-Lipophilic Balance) value" of a nonionic surfactant is a value defined by the following equation using the Griffin method. HLB value = 20 × [sum of the chemical formula weight of the hydrophilic part]/molecular weight The "degree of substitution" of cellulose ether is also called the degree of etherification, which means that one of the three hydroxyl groups located on the glucose ring of cellulose is substituted by an alkoxy group. The number of hydroxyl groups (average value). The degree of substitution can theoretically have a value between 0 and 3. Generally speaking, the higher the degree of substitution, the more hydrophilic it is. The degree of substitution can be converted from the value measured by the degree of substitution analysis method of hydroxypropyl methylcellulose recorded in the 18th revised Japanese Pharmacopoeia. The so-called "unit" of a polymer refers to an atomic group formed by the polymerization of monomers with the aforementioned monomer as the main body. The unit may be a unit directly formed by a polymerization reaction, or may be a unit in which a part of the aforementioned units is converted into another structure by processing the polymer. Hereinafter, the unit mainly composed of monomer a is also referred to as "monomer a unit".

The dispersion of the present invention (hereinafter also referred to as "this dispersion") contains: particles of a tetrafluoroethylene polymer (hereinafter also referred to as "F polymer") (hereinafter also referred to as "F particles"), nonionic Surfactant, cellulose ether with a degree of substitution above 1.4 and water. This dispersion has excellent dispersion stability and handling properties, and molded articles such as coating films (polymer layers) formed from this dispersion have excellent heat resistance and electrical characteristics (low linear expansion) due to the tetrafluoroethylene polymer. Coefficient, low dielectric constant and low dielectric tangent) and other physical properties, especially its surface appearance. In addition, in this specification, the so-called "excellent surface appearance" also includes the following two: excellent surface smoothness, such as "less surface roughness", or "no streaks, cracks or defects on the surface, etc." for visual inspection or analysis of the machine. The observed appearance is excellent. The reasons why this dispersion has excellent dispersion stability, suppressed foaming and excellent handleability are not necessarily clear, but we think as follows.

In an aqueous dispersion containing F particles and a nonionic surfactant, the nonionic surfactant will be adsorbed on the surface of the F particles, thereby improving the water dispersibility of the F particles. We believe that the interaction caused by this adsorption is in a state of equilibrium, and the non-adsorbed non-ionic surfactant can also be regarded as existing at the gas-liquid interface, etc. That is, while the stability of the aqueous dispersion is improved by the nonionic surfactant, it is in a state in which bubbles are easily generated. It can also be considered that the aqueous dispersion is in a state in which the agglomeration or coarsening of F particles is easy to occur starting from the bubbles. In order to stably disperse the low surface tension F particles in water, an excessive amount of nonionic surfactant is needed. This not only easily results in the above state, but also significantly reduces the surface tension of the dispersion itself, reducing the physical properties of the liquid such as thixotropy. It also reduces the handling properties of the aqueous dispersion. In addition to nonionic surfactants and water, this dispersion also contains specific cellulose ethers. It is speculated that this specific cellulose ether acts on the fluidity of this dispersion and the adsorption of F particles by the surfactant. We believe that the defoaming effect caused by the use of the surfactant and the maintenance of liquid physical properties such as thixotropy are The role of the so-called trade-off relationship is highly balanced. As a result, it is thought that this dispersion liquid can be obtained which can suppress the formation of coarse particles and is excellent in dispersion stability, and can suppress foaming and is easy to handle. In addition, when the present dispersion contains the two specific surfactants described below or monoalcohols with 1 to 6 carbon atoms, and furthermore when the F polymer has an oxygen-containing polar group, the above-mentioned action mechanism becomes more significant.

The F polymer of the present invention is a polymer containing units (hereinafter also referred to as "TFE units") mainly composed of tetrafluoroethylene (hereinafter also referred to as "TFE"). The F polymer may be thermally fusible or non-thermal fusible. Here, the hot-meltable polymer means a polymer having a melt flow rate at a temperature of 1 to 1000 g/10 minutes under a load of 49 N. In addition, the term "non-thermal meltable polymer" means a polymer that does not have a melt flow rate at a temperature of 1 to 1000 g/10 minutes under a load of 49 N. The melting temperature of the heat-fusible F polymer is preferably 180°C or higher, more preferably 200°C or higher. In this case, molded articles such as coating films (polymer layers) formed from this dispersion tend to have excellent heat resistance. The melting temperature of the aforementioned F polymer is preferably 325°C or lower, more preferably 320°C or lower. Since it is easier to exhibit the above-mentioned mechanism of action, the melting temperature of the F polymer is preferably 180°C to 325°C, more preferably 200°C to 325°C, and more preferably 200°C to 320°C.

The glass transition point of F polymer is preferably above 50°C, more preferably above 75°C. The glass transition point of F polymer is preferably below 150°C, more preferably below 125°C. The fluorine content of F polymer is preferably 70% by mass or more, more preferably 72 to 76% by mass. The surface tension of F polymer should be 16~26mN/m. In addition, the surface tension of the F polymer can be measured by placing a droplet of a mixed liquid (manufactured by Wako Pure Chemical Industries, Ltd.) for a wet tension test specified in JIS K 6768 on a flat plate made of the F polymer.

F polymers are preferably: polytetrafluoroethylene (PTFE), polymers containing TFE units and units with ethylene as the main body (ETFE), polymers containing TFE units and units with propylene as the main body, polymers containing TFE units and units with ethylene as the main body. Polymers (PFA) with perfluoro(alkyl vinyl ether) (PAVE) as the main unit (PAVE unit), polymers (FEP) containing TFE units and hexafluoropropylene as the main unit, preferably PFA Or FEP, preferably PFA. The F polymer may be used individually by 1 type, or 2 or more types may be used in combination, and may further contain units based on other copolymerized monomers. PTFE can include low molecular weight PTFE and modified PTFE. PAVE is preferably CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ , or CF ₂ =CFOCF ₂ CF ₂ CF ₃ (hereinafter also referred to as "PPVE"), and preferably PPVE.

The F polymer preferably has an oxygen-containing polar group, more preferably a hydroxyl-containing group or a carbonyl-containing group, and more preferably a carbonyl-containing group. In this case, the present dispersion tends to have excellent dispersion stability and handling properties. In addition, molded articles such as coating films (polymer layers) formed from this dispersion tend to have excellent physical properties such as heat resistance, electrical characteristics (low coefficient of linear expansion, low dielectric constant, and low dielectric tangent), or surface appearance. The group containing hydroxyl group is preferably a group containing alcoholic hydroxyl group, preferably -CF ₂ CH ₂ OH or -C(CF ₃ ) ₂ OH. Groups containing carbonyl groups are preferably carboxyl groups, alkoxycarbonyl groups, amide groups, isocyanate groups, urethane groups (-OC(O)NH ₂ ), and acid anhydride residues (-C(O)OC(O)-) , acyl imine residue (-C(O)NHC(O)-, etc.) or carbonate group (-OC(O)O-), preferably an acid anhydride residue.

When the F polymer has oxygen-containing polar groups, the number of oxygen-containing polar groups in the F polymer is calculated based on the number of main chain carbon atoms of the F polymer. The number of main chain carbon atoms per 1×10 ⁶ should be 10 to 5000. It should be 100~3000. At this time, the respective interactions between the F polymer and the nonionic surfactant, and between the F polymer and the cellulose ether will be balanced, and it is particularly easy to improve the liquid physical properties of the dispersion. 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 included in the monomer-based unit in the F polymer, or may be included in the terminal group of the main chain of the F polymer, preferably the former. Examples of the latter include: F polymers having an oxygen-containing polar group as a terminal group derived from a polymerization initiator, a chain transfer agent, etc.; and F polymers obtained by subjecting F polymers to plasma treatment or ionizing radiation treatment.

The F polymer is preferably a polymer containing a TFE unit and a PAVE unit and having a carbonyl-containing group; more preferably, it is a polymer containing a TFE unit, a PAVE unit and a monomer having a carbonyl-containing group as the main body units, and these units are included in order of 90~99 mol%, 0.99~9.97 mol%, and 0.01~3 mol% relative to all units. Specific examples of the F polymer include the polymer described in International Publication No. 2018/16644. The monomer having a carbonyl group-containing group is preferably itaconic anhydride, citraconic anhydride or 5-norphen-2,3-dicarboxylic anhydride (hereinafter also referred to as "NAH"), and more preferably NAH.

In the present invention, the D50 of F particles is preferably 1 μm or more and less than 10 μm. F particles may be solid particles or non-hollow particles. F particles may be secondary particles formed from nanometer-level microparticles. The D50 of F particles is preferably 1.0µm or more, more preferably 1.5µm or more. The D50 of F particles should be 6µm or less, more preferably 5µm or less. In addition, D90 of F particles is preferably 8 µm or less, more preferably 6 µm or less. If the D90 of the F particles is below the above upper limit, the above action mechanism will be more likely to be exhibited, and the present dispersion with a smaller number of coarse particles will be easily obtained.

The specific surface area of F particles is preferably 1~25m ² /g, more preferably 6~15m ² /g. In this case, the present dispersion tends to have excellent dispersion stability and handling properties. In addition, molded articles such as coating films (polymer layers) formed from this dispersion tend to have excellent physical properties such as heat resistance, electrical characteristics (low coefficient of linear expansion, low dielectric constant, and low dielectric tangent), or surface appearance. We believe that if the specific surface area of the F particles is within the above range, the surface of the F particles will be easily wetted by water or monoalcohols with 1 to 6 carbon atoms described later, and the aggregates of the F particles will be easily broken down, making it easier to exhibit the above-mentioned properties. Mechanism of action.

F particles are particles containing F polymer and are preferably composed of F polymer. F particles are preferably particles of a heat-melting F polymer with a melting temperature of 200 to 325°C and an oxygen-containing polar group. At this time, the above-mentioned mechanism of action can be better demonstrated, and it is easier to inhibit the aggregation of F particles. F particles may contain resins or inorganic compounds other than F polymers, and may have a core-shell structure with F polymers as the core and resins or inorganic compounds other than F polymers as the outer shell. F particles may also be formed with F polymers as the core. A core-shell structure in which the material is the shell and a resin or inorganic compound other than F polymer is the core. Here, resins other than F polymer include aromatic polyester, polyamide imine, polyimide, and maleimide, and examples of inorganic compounds include silicon dioxide and boron nitride.

One type of F particles may be used, or two or more types may be used. In addition, F particles may be mixed with particles of a non-thermally fusible tetrafluoroethylene polymer and used. F particles are preferably particles of a hot-fusible F polymer with a melting temperature of 200 to 325°C, and more preferably particles of a hot-meltable F polymer with a melting temperature of 200 to 325°C and having an oxygen-containing polar group. Furthermore, the particles of the non-thermally fusible tetrafluoroethylene-based polymer are preferably particles of non-thermally fusible PTFE. In this case, the aggregation-inhibiting effect of the particles of the hot-fusible F polymer is balanced with the holding effect of the fibrillation of the non-heat-fusible tetrafluoroethylene polymer, making it easy to improve the dispersion of the present dispersion. In addition, in molded articles such as coating films (polymer layers) formed therefrom, the electrical characteristics of the non-thermal fusible tetrafluoroethylene-based polymer are easily exhibited to a high degree.

Examples of the nonionic surfactant contained in this dispersion include ethylene glycol-based surfactants, acetylene-based surfactants, polysiloxane-based surfactants, and fluorine-based surfactants. It is preferable to use an alcohol-based surfactant containing an HLB value of less than 10 (hereinafter also referred to as "surfactant 1") as the nonionic surfactant. The HLB value of surfactant 1 is preferably less than 4.

The surfactant 1 is preferably an acetylene glycol surfactant. Acetylene glycol surfactants are surfactants with carbon-carbon triple bonds in their molecules. Examples of acetylene glycol-based surfactants include acetylene glycol (having an acetylene bond and two hydroxyl groups in the same molecule) surfactant, and acetylene glycol-added surfactant with alkylene oxides such as ethylene oxide and propylene oxide. Specifically, Take the compound represented by the following general formula (1) or (2).

[Chemical formula 1]

(In the formula, R ¹ and R ² each independently represent an alkyl group with 3 to 9 carbon atoms, R ³ and R ⁴ each independently represent an alkylene group with 1 to 4 carbon atoms, m and n each independently represent an integer of 1 or more, And the total of m and n is 2~50). Examples of the surfactant 1 belonging to the acetylene glycol-based surfactant include: "Surfynol (registered trademark)" series, "Olfine (registered trademark)" series (both manufactured by Nissin Chemical Industry Co., Ltd.); "Acetylenol (registered trademark) )" series (manufactured by Kawaken Fine Chemicals Co., Ltd.).

It is also suitable to contain a nonionic surfactant with an HLB value of 10 or more (hereinafter also referred to as "surfactant 2") as a nonionic surfactant. The surfactant 2 is preferably a polysiloxy surfactant, preferably a polyoxyalkylene modified dimethyl group having a polyoxyalkylene structure as the hydrophilic part and a polydimethylsiloxane structure as the hydrophobic part. Siloxane.

Polyoxyalkylene modified dimethylsiloxane can have polydimethylsiloxane units (-(CH ₃ ) ₂ SiO _2/2 -) in the main chain and polydimethylsiloxane in the side chain. The oxyalkane unit may also have polydimethylsiloxane units in both the main chain and the side chain. The polyoxyalkylene-modified polydimethylsiloxane is preferably: a polyoxyalkylene-modified polydimethyl containing a dimethylsiloxane unit in the main chain and an oxyalkylene group in the side chain. Siloxane, or polyoxyalkylene-modified polydimethylsiloxane containing dimethylsiloxane units in the main chain and having an oxyalkylene group at the end of the main chain. Furthermore, the oxyalkylene group contained in the polyoxyalkylene-modified dimethylsiloxane may be composed of only one type of oxyalkylene group, or may be composed of two or more types of oxyalkylene groups. In the latter case, different types of oxyalkylene groups may be connected randomly or block-wise.

Examples of surfactants 2 that are polysilicone-based surfactants include: "BYK-347", "BYK-349", "BYK-378", "BYK-3450", "BYK-3451", "BYK-3455" ", "BYK-3456" (manufactured by BYK Japan Co., Ltd.), "KF-6011", "KF-6043" (manufactured by Shin-Etsu Chemical Industry Co., Ltd.). Furthermore, specific examples of other nonionic surfactants include: "Ftergent" series (manufactured by NEOS Corporation), "Surflon" series (manufactured by AGC SEIMI CHEMICAL Corporation), "MEGAFACE" series (manufactured by DIC Corporation), and "UNIDYNE" series (manufactured by Daikin Industrial Co., Ltd.), "Tergitol" series (manufactured by Dow Chemical Company, "Tergitol TMN-100X", etc.).

Relative to the F particles in this dispersion, the content of the nonionic surfactant is preferably in the range of 1 to 15 mass %, and more preferably in the range of 3 to 10 mass %. One type of nonionic surfactant may be used, or two or more types may be used. In particular, it is preferable that this dispersion liquid contains both surfactant 1 and surfactant 2 as nonionic surfactants because the above-described action mechanism can be more easily exhibited. When the dispersion contains both surfactant 1 and surfactant 2 as nonionic surfactants, the mass ratio of surfactant 1 to surfactant 2 is not particularly limited, for example, it can be between 5:95 and 95: Set appropriately within the range of 5.

The degree of substitution of the cellulose ether contained in this dispersion is 1.4 or more. The degree of substitution of cellulose ether is preferably 1.9 or more, more preferably 2.1 or more. Furthermore, the substitution degree of cellulose ether is preferably 2.9 or less, more preferably 2.7 or less. The degree of substitution of cellulose ether is preferably in the range of 1.4~2.9, more preferably 1.9~2.9, more preferably 1.9~2.7. If the substitution degree of cellulose ether meets the above range, its viscosity-increasing effect or interaction with F particles will be balanced with the above-mentioned nonionic surfactant, and it will be easier to exhibit the above-mentioned mechanism of action, especially in When the nonionic surfactant has a hydroxyl group or a polyoxyalkylene group and the cellulose ether has a hydroxyl group, the above action mechanism is likely to be significantly exhibited.

Examples of cellulose ether include alkyl cellulose, carboxyalkyl cellulose, hydroxyalkyl cellulose or hydroxyalkyl alkyl cellulose, among which carboxyalkyl cellulose, hydroxyalkyl cellulose or hydroxyalkyl cellulose is preferred. Alkyl cellulose.

Examples of carboxyalkyl cellulose include carboxymethyl cellulose. Examples of hydroxyalkyl cellulose include hydroxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose. Examples of hydroxyalkyl alkyl cellulose include hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxyethyl ethyl cellulose, and hydroxyethyl ethyl methyl cellulose. These may be used individually by 1 type, and may be used in combination of 2 or more types. Among them, hydroxyalkyl cellulose or hydroxyalkylalkyl cellulose is more preferred, hydroxyalkyl cellulose is more preferred, and hydroxyethyl cellulose is more preferred.

The weight average molecular weight of cellulose ether is preferably 1,000~10,000. In addition, the weight average molecular weight can be measured, for example, by gel permeation chromatography (GPC) using a differential refractive index detector. Specific examples of cellulose ethers include "SUNROSE (registered trademark)" series (manufactured by Nippon Paper Co., Ltd.), "METOLOSE (registered trademark)" series (manufactured by Shin-Etsu Chemical Industry Co., Ltd.), and "HEC CF grade" (manufactured by Sumitomo Seika Co., Ltd. ).

The dispersion may further contain monoalcohols with 1 to 6 carbon atoms. The monoalcohol having 1 to 6 carbon atoms is a compound that is liquid at 25°C under atmospheric pressure. It is preferably a compound with a boiling point of 160°C or lower, and more preferably a compound with a boiling point of 120°C or lower. In addition, it is suitable to be a water-soluble compound with a surface tension of 20~30mN/m, and it is suitable to be azeotrope with water. In addition, in this specification, "water solubility" means that the solubility in water is 100g/L or more.

The aforementioned monoalcohols with 1 to 6 carbon atoms are preferably methanol (23mN/m), ethanol (23mN/m), 1-propanol (24mN/m), 2-propanol (22mN/m), and 1-butanol. (25mN/m), 2-butanol (24mN/m), isobutanol (23mN/m), 1-methoxy-2-propanol (26mN/m), 2-propoxy-ethanol (27mN /m), 1-propoxy-2-propanol (25mN/m), 2-ethoxyethanol (26mN/m), more preferably ethanol. In addition, the numerical value in parentheses is the surface tension of each unit alcohol. One type of these may be used, or two or more types may be used. When two or more types of the aforementioned monoalcohols are used, they should be compatible with each other.

In addition to the aforementioned monoalcohol and water, this dispersion can also use other dispersion media within the scope that does not impair the effect of the present invention. The other dispersion medium is preferably mixed with the aforementioned monoalcohol and water. Other dispersion media include: N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, 3-Methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N,N-diethylformamide, hexamethyltriphosphate Amides such as amide and 1,3-dimethyl-2-imidazolidinone; ketones such as acetone and methyl ethyl ketone.

The dispersion may further contain inorganic fillers. In this case, molded articles such as coating films (polymer layers) formed from the present dispersion tend to have excellent electrical properties and low linear expansion. The shape of the inorganic filler can be any of spherical, needle-shaped (fiber-shaped), and plate-shaped. Specifically, it can be spherical, scaly, layered, leaf-shaped, almond-shaped, columnar, comb-shaped, Isometric, leaf-shaped, mica-shaped, block-shaped, plate-shaped, wedge-shaped, rosette-shaped, grid-shaped, corner column-shaped. Examples of inorganic fillers include silicon compounds such as quartz powder, silica, wollastonite, talc, silicon nitride, silicon carbide, and mica; nitrogen compounds such as boron nitride and aluminum nitride; aluminum oxide, zinc oxide, Metal oxides such as titanium oxide, cerium oxide, beryllium oxide, magnesium oxide, nickel oxide, vanadium oxide, copper oxide, iron oxide, silver oxide, etc.; carbon fibers; carbon allotropes such as graphite, graphene, carbon nanotubes, etc. ;Silver, copper and other metals. One type of inorganic filler may be used, or two or more types may be used in combination. The D50 of inorganic filler should be 0.1~50µm. The surface of the inorganic filler can also be surface treated with a silane coupling agent.

Suitable specific examples of the inorganic filler include: silica filler ("Admafine (registered trademark)" series (manufactured by Admatechs), "SFP (registered trademark)" series (manufactured by Denka Co., Ltd.), "E-SPHERES" series (Pacific Cement Co., Ltd.), etc.), zinc oxide fillers ("FINEX (registered trademark)" series (manufactured by Sakai Chemical Industry Co., Ltd.), etc.), titanium oxide fillers ("TIPAQUE (registered trademark)" series (manufactured by Ishihara Sangyo Co., Ltd.), " JMT (registered trademark)" series (manufactured by Tayca Co., Ltd., etc.), talc fillers ("SG" series (manufactured by Nippon Talc Co., Ltd.), etc.), talc fillers ("BST" series (manufactured by Nippon Talc Co., Ltd.), etc.), nitrided Boron filler ("HP40MF" series, "HP40J" series (all manufactured by Mizushima Alloy Iron Co., Ltd.), "UHP" series (manufactured by Showa Denko Corporation), "GP" and "HGP" grades of the "Denka Boron Nitride" series (Denka company system), etc.). When the dispersion contains an inorganic filler, the content of the inorganic filler in the dispersion is preferably 1 to 25% by mass.

The dispersion may also contain other resins different from the F polymer. The other resin may be included in the present dispersion liquid in the form of non-hollow particles, and may also be dissolved or dispersed in the water constituting the present dispersion liquid and optionally contained in a liquid state such as monoalcohol having 1 to 6 carbon atoms or other dispersion media. included in the dispersion medium (hereinafter also referred to as "liquid dispersion medium"). Examples of other resins include polyester resins such as liquid crystalline aromatic polyester, polyimide resin, polyamideimide resin, epoxy resin, maleimide resin, urethane resin, and polyphenylene ether. Resin, polyphenylene oxide resin, polyphenylene sulfide resin. Other resins are preferably aromatic polymers, preferably selected from the group consisting of aromatic polyamide imide, aromatic polyamide acid, aromatic polyamide imine and aromatic polyamide imine. At least one aromatic imine polymer in the group constituted by the substance. The aromatic polymer is preferably contained in the present dispersion in the form of a varnish dissolved in the liquid dispersion medium.

Specific examples of aromatic imine polymers include: "UPIA-AT" series (manufactured by Ube Kosan Co., Ltd.), "Neopulim (registered trademark)" series (manufactured by MITSUBISHI GAS CHEMICAL Co., Ltd.), "SPIXAREA (registered trademark)" Series (manufactured by SOMAR Co., Ltd.), "Q-PILON (registered trademark)" series (manufactured by PI Technology Research Institute), "WINGO" series (manufactured by Wingo Technology Co., Ltd.), "Tohmide (registered trademark)" series (manufactured by T&K TOKA Co., Ltd.) , "KPI-MX" series (manufactured by Kawamura Industrial Co., Ltd.), "HPC-1000", "HPC-2100D" (all manufactured by SHOWA DENKO MATERIALS Co., Ltd.). When the dispersion further contains other resins, the content of the other resins relative to the F particles is preferably 1 to 25% by mass.

This dispersion may also contain: thixotropy imparting agent, viscosity regulator, defoaming agent, dehydrating agent, plasticizer, weathering agent, antioxidant, heat stabilizer, slip agent, antistatic agent, whitening agent, coloring agent Additives such as agents, conductive agents, release agents, flame retardants, etc.

This dispersion can be obtained by mixing the following components: F particles, nonionic surfactant, cellulose ether and water; and, if necessary, the aforementioned monoalcohol having 1 to 6 carbon atoms, other dispersion media, inorganic fillers, Other resins, additives, etc. This dispersion can be obtained by mixing F particles, nonionic surfactant, cellulose ether and water as a whole. It can be obtained by mixing them individually in sequence, or it can be made into a masterbatch in advance and then mixed with the remaining ingredients. Obtained by mixing. The mixing order is not particularly limited, and the mixing method may be to mix the entire product together or to mix it divided into multiple times.

For example, F particles are dispersed in a part of water in advance, then nonionic surfactant and cellulose ether are added and mixed in sequence, and then the resulting mixture is added to the remaining water to obtain the present dispersion, which can improve dispersion. It is better to look at it from the point of view. The nonionic surfactant can be added directly or in the form of an aqueous solution. In addition, when both the aforementioned surfactant 1 and surfactant 2 are used as nonionic surfactants, the order of addition is not particularly limited, and they may be added in the form of an aqueous solution in which they have been dissolved. The method of adding the cellulose ether can be to add the cellulose ether in the form of powder or its aqueous solution, or in the state of being dispersed or dissolved in a liquid defoaming agent or the like. Moreover, when the aforementioned monoalcohol having 1 to 6 carbon atoms, other dispersion media, inorganic fillers, other resins, additives, etc. are further mixed as necessary, the mixture may be mixed when the F particles and water are mixed, or the aforementioned mixture may be added to the water. Mix while doing so.

Examples of mixing devices used to obtain this dispersion include: Heinz mixers, pressurized kneaders, Banbury internal mixers, planetary mixers and other mixing devices with paddles; ball mills, attritors, basket mills Machine, sand mixer, sand mill, Dyno-Mill, DISPERMAT, SC-MILL, nail mill and stirring mill and other crushing devices with media; fine fluid homogenizer, Nanomizer, Ultimizer, ultrasonic homogenizer, dissolver , disperser, high-speed impeller disperser, film rotary high-speed mixer, rotation-revolution mixer, V-shaped mixer and other dispersing devices with other mechanisms.

The content of the F particles in this dispersion is preferably more than 30% by mass, from the viewpoint of making it easier to form a thicker layered molded article and to easily impart a high degree of physical properties of the F polymer to the resulting molded article. It is 35 mass% or more. The content of F particles is preferably 75 mass% or less, more preferably 60 mass% or less. The content of the nonionic surfactant in this dispersion is preferably 1 to 15 parts by mass, more preferably 3 to 10 parts by mass relative to 100 parts by mass of F particles.

From the viewpoint of improving the fluidity of this dispersion, the content of the cellulose ether in this dispersion is preferably 0.01% by mass or more, and more preferably 0.02% by mass or more relative to this dispersion. The content of cellulose ether is preferably 1% by mass or less, and preferably 0.1% by mass or less.

The water content in this dispersion is preferably 25 mass% or more, more preferably 40 mass% or more. The water content is preferably less than 70% by mass, more preferably 65% by mass or less. In addition, the content of water in this dispersion is preferably 60 to 180% by mass relative to the content of F particles.

When the present dispersion contains monoalcohol having 1 to 6 carbon atoms, its content is preferably 0.1% by mass or more, more preferably 1% by mass or more relative to the dispersion. The content of monoalcohols having 1 to 6 carbon atoms is preferably 10% by mass or less, and preferably 5% by mass or less. From the perspective of the dispersion stability of F particles, we also believe that even if a large amount of nonionic surfactant is contained, the monoalcohol with 1 to 6 carbon atoms will still exert a foam-suppressing or foam-breaking effect. Defoaming agent function.

The viscosity of this dispersion is preferably 10mPa·s or more, more preferably 100mPa·s or more. The viscosity of this dispersion is preferably 10000mPa·s or less, more preferably 3000mPa·s or less. In this case, the present dispersion has excellent coating properties and can easily form a molded article having a coating film (polymer layer) of any thickness. Furthermore, the present dispersion having a viscosity within the above-mentioned range can easily exhibit the physical properties of the F polymer to a high degree in a molded article formed therefrom. The thixotropy ratio of this dispersion is preferably 1.0~3.0. In this case, the present dispersion has excellent coating properties and homogeneity, and can easily produce denser molded products.

From the viewpoint of improving long-term storage properties, the pH of this dispersion is preferably 8 to 10. The pH of the dispersion can be adjusted by pH adjusters (amines, ammonia, citric acid, etc.) or pH buffers (hydroxymethyl)aminomethane, ethylenediaminetetraacetic acid, ammonium bicarbonate, ammonium carbonate, ammonium acetate, etc.) to adjust.

The dielectric constant of the molded article formed from this dispersion is preferably 2.4 or less, more preferably 2.0 or less. Moreover, the dielectric constant should be greater than 1.0. The dielectric tangent of the molded article is preferably 0.0022 or less, more preferably 0.0020 or less. Moreover, the dielectric tangent should be greater than 0.0010. The thermal conductivity of the molded product is preferably 1W/m·K or more, more preferably 3W/m·K or more.

If this dispersion is subjected to a molding method such as extrusion into a sheet, molded products such as sheets containing the F polymer can be formed. The extruded sheet can also be further subjected to compression molding, calendering, etc. to be cast. The sheet should be further heated to remove the liquid dispersion medium and then fired into F polymer.

The thickness of the sheet formed from this dispersion is preferably 1~1000µm. The suitable ranges of the dielectric constant, dielectric tangent, and thermal conductivity of the sheet are the same as the ranges of the dielectric constant, dielectric tangent, and thermal conductivity of the above-mentioned formed article, respectively. Furthermore, the thermal conductivity of the sheet means the thermal conductivity in the in-plane direction of the sheet. The linear expansion coefficient of the sheet should be below 100 ppm/℃, more preferably below 80 ppm/℃. The lower limit of the linear expansion coefficient of the sheet is 30ppm/℃. In addition, the linear expansion coefficient means a value obtained by measuring the linear expansion coefficient of the test piece in the range of 25°C or more and 260°C or less according to the measurement method specified in JIS C 6471:1995.

If this sheet is laminated on a base material, a laminated body can be formed. Examples of methods for producing a laminated body include extrusion molding of the present dispersion onto the aforementioned base material, a method of thermocompression bonding a sheet and the aforementioned base material, and the like. Examples of base materials include: metal substrates such as metal foils of copper, nickel, aluminum, titanium, and other alloys thereof; polyimide, polyamide, polyetheramide, polyphenylene sulfide, and polyaryl ether ketone , heat-resistant resin films such as polyamide imide, liquid crystalline polyester, tetrafluoroethylene polymer, etc.; prepreg substrate (precursor to fiber reinforced resin substrate), silicon carbide, aluminum nitride, silicon nitride Ceramic substrates, etc.; glass substrates.

The shape of the base material can be flat, curved, or concave and convex. In addition, the shape of the base material may be any of a foil shape, a plate shape, a film shape, and a fiber shape. The ten-point average roughness of the surface of the substrate should be 0.01~0.05µm. The surface of the substrate can be surface treated with silane coupling agent or plasma treated. The silane coupling agent is preferably: 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxy Silane coupling agents with functional groups, such as silane, 3-methacryloxypropyltriethoxysilane, and 3-isocyanatepropyltriethoxysilane. The peel strength between the sheet and the base material should be 10~100N/cm.

Furthermore, if this dispersion is placed on the surface of a base material and heated to form a polymer layer containing F polymer (hereinafter also referred to as "F layer"), a base material layer composed of a base material and an F layer can be obtained in sequence. layered body. The F layer is preferably formed by disposing the dispersion on the surface of the substrate, heating to remove the liquid dispersion medium, and then further heating to sinter the F polymer. If the base material is separated from this laminated body, an F polymer-containing sheet can be obtained. The base material can be the same as the base material that can be laminated with the sheet mentioned above, and the suitable aspects are also the same.

Methods for preparing the dispersion include coating, droplet discharging, and dipping. Preferably, it is roller coating, knife coating, rod coating, die coating, or spray coating. Heating when removing the liquid dispersion medium should be carried out at 100~200℃ for 0.1~30 minutes. At this time, the heated liquid dispersion medium does not need to be completely removed. It only needs to be removed to the extent that the layer formed by filling the F particles can maintain a self-supporting film. In addition, air can also be blown during heating to promote the removal of the liquid dispersion medium through air drying.

When firing the F polymer, the heating should be carried out at a temperature above the melting temperature of the F polymer, preferably at 360 to 400°C for 0.1 to 30 minutes. In terms of heating devices, ovens and ventilation drying furnaces can be used. The heat source in the device can be a contact heat source (hot air, heating plate, etc.) or a non-contact heat source (infrared ray, etc.). In addition, each heating may be performed under normal pressure or under reduced pressure. In addition, the gas environment during each heating may be any one of an air environment and an inert gas (helium, neon, argon, nitrogen, etc.) gas environment.

The F layer is formed through the steps of preparing and heating the dispersion. These steps may be performed once each, or may be repeated two or more times. For example, the dispersion liquid can be placed on the surface of the substrate and heated to form the F layer, and then the dispersion liquid can be placed on the surface of the F layer and heated to form the second layer F layer. Alternatively, after disposing the dispersion liquid on the surface of the base material and removing the liquid dispersion medium by heating, the dispersion liquid may be further disposed on the surface and heated to form the F layer. The dispersion can be placed on only one surface of the base material, or can be placed on both sides of the base material. In the former case, a laminate having a base material layer and an F layer located on one surface of the base material layer can be obtained; in the latter case, a laminated body having a base material layer and F layers located on both surfaces of the base material layer can be obtained. of layered bodies. The thickness of the F layer varies depending on the purpose of the laminate, but it should be in the range of 1~1000µm.

Suitable specific examples of the laminated body include: a metal-clad laminated body having a metal foil and an F layer located on at least one surface of the metal foil; and a metal-clad laminated body having a polyimide film and F layers located on both surfaces of the polyimide film. Multilayer film. The appropriate ranges of the thickness, dielectric constant, dielectric tangent, thermal conductivity, linear expansion coefficient, and peel strength of the F layer and the base material layer of the F layer are related to the thickness, dielectric constant, and dielectric properties of the sheet formed from the dispersion. The appropriate ranges for electrical tangent, thermal conductivity, linear expansion coefficient, and peel strength of the sheet and base material are the same.

This dispersion can be effectively used as a material for imparting insulation, heat resistance, corrosion resistance, chemical resistance, water resistance, impact resistance, and thermal conductivity. Specifically, this dispersion can be used in: printed wiring boards, thermal interface materials, substrates for power modules, coils used in power devices such as motors, vehicle engines, heat exchangers, small glass bottles (Vial), syringes ( syringe), ampoules, medical wires, storage batteries such as lithium ion batteries, primary batteries such as lithium batteries, radical batteries, solar cells, fuel cells, lithium ion capacitors, hybrid capacitors, capacitors, capacitors (aluminum electrolytic capacitors, tantalum Electrolytic capacitors, etc.), electrochromic components, electrochemical switching components, electrode binders, electrode separators, electrodes (positive electrode, negative electrode). In addition, this dispersion can also be effectively used as an adhesive for bonding parts. Specifically, this dispersion can be used for: the bonding of ceramic parts, the bonding of metal parts, the bonding of IC chips or electronic parts such as resistors and capacitors in the substrates of semiconductor components or module parts, the bonding of circuit substrates and heat sinks, LEDs Wafer to substrate bonding.

Molded products and laminates such as sheets formed from this dispersion can be effectively used as antenna parts, printed circuit boards, aircraft parts, automobile parts, sports equipment, food industry products, heat dissipation parts, etc. Specifically, it is effective as: electric wire covering materials (aircraft wires, rectangular wires, FFC (Flexible flat cable), etc.), enameled wire covering materials used in motors such as electric vehicles, etc., power generation covering materials, electrical Insulating tape, insulating tape for oil drilling, oil transportation hoses, hydrogen tanks, materials for printed circuit boards, separation membranes (microporous filtration membranes, ultrafiltration membranes, reverse osmosis membranes, ion exchange membranes, dialysis membranes, gas separation membranes, etc.) , electrode binders (for lithium batteries, fuel cells, etc.), carrier films for fuel cells, tape base films for semiconductor manufacturing processes (dicing tapes, pick-up tapes, etc.), release films for semiconductor molding, liquid crystal antennas, reflective Boards, transmission lines, base films for COF (Chip on Film; chip on film), electrostatic chucks for semiconductor manufacturing processes, electrostatic chucks for display manufacturing processes, copy rolls, furniture, automobile dashboards, home appliances, etc. Housing, sliding components (load bearings, yaw bearings, sliding shafts, valves, bearings, bushings, seals, thrust washers, wear rings, pistons, sliding switches, gears, cams, conveyor belts, food conveying belts etc.), tension cables, wear-resistant pads, wear-resistant strips, lamp tubes, test sockets, wafer guides, wear parts of centrifugal pumps, chemical supply pumps and water supply pumps, tools (shovel, file, cone, etc.) saws, etc.), boilers, hoppers, pipes, ovens, baking molds, chutes, racket strings, molds, toilets, container covering materials, heat dissipation substrates for power devices, heat dissipation components for wireless communication devices, transistors, thyristors, rectifiers , transformers, power MOSFETs, CPUs, heat sinks, metal heat sinks, blades of windmills or wind power generation equipment or aircraft, computer or monitor casings, electronic device materials, automobile interior and exterior decorations, heating treatment in low oxygen Sealing materials for processing machines or vacuum ovens, plasma processing equipment, etc., heat dissipation parts, and electromagnetic wave shielding parts in the processing units of sputtering or various dry etching equipment.

Molded products and laminates such as sheets formed from this dispersion can be effectively used as electronic substrate materials, protective films, or heat dissipation substrates for flexible printed wiring boards, rigid printed wiring boards, etc., and are particularly effective as heat dissipating substrates suitable for automobiles.

EXAMPLES The present invention will be described in detail below through examples, but the present invention is not limited thereto. 1. Preparation of each component [F polymer] F particles 1: Particles (D50: 2.0µm, specific surface area: 7m ² /g) of tetrafluoroethylene polymer (melting temperature: 300°C), which are in order 97.9 mol%, 0.1 mol%, and 2.0 mol% contain TFE units, NAH units and PPVE units, and each 1×10 ⁶ main chain carbon number has 1000 carbonyl-containing groups. F particle 2: is tetrafluoro Particles (D50: 2.2µm, specific surface area: 6m ² /g) of ethylene polymer (melting temperature: 300°C), which contain TFE units and PPVE units in order of 97.5 mol% and 2.5 mol%, and each 1×10 ⁶ main chain carbon atoms with 50 carbonyl-containing groups [nonionic surfactant] Surfactant 1: It is a nonionic alcohol surfactant ("Surfynol DF-110D" (trade name, Manufactured by Nissin Chemical Industry Co., Ltd.)), it has 1 ethynyl group and 2 hydroxyl groups, and HLB value = 3. Surfactant 2: It is a non-ionic polysiloxane surfactant, which has polysiloxane in the main chain. Alkyl chain, with polyoxyethylene group in the side chain, and HLB value = 13 [Cellulose ether] Cellulose ether 1: Hydroxyethyl cellulose with a degree of substitution of 2.4 Cellulose ether 2: Hydroxyethyl cellulose with a degree of substitution of 1.5 Cellulose ether 3: hydroxyethyl cellulose with a degree of substitution of 1.3

2. Production example of aqueous dispersion [example 1] Use an autorotation and revolution mixer (manufactured by THINKY Co., Ltd., trade name "Degassing Rentaro (registered trademark) ARE-310") to stir F particles 1, surfactant 1, surfactant 2, cellulose ether 1 and water at 2000 rpm for 10 minutes, and obtained containing F particles 1 (46.5 parts by mass), surfactant 1 (0.9 parts by mass), surfactant 2 (2.3 parts by mass), cellulose ether 1 (0.3 parts by mass) and water (50.0 parts by mass) Dispersion 1 (viscosity: 1000mPa·s).

[Example 2] Except that no surfactant 2 was added, the same method as Example 1 was used to obtain F particles 1 (46.5 parts by mass), surfactant 1 (3.2 parts by mass), cellulose ether 1 (0.3 parts by mass) and water (50.0 mass parts) dispersion 2. [Example 3] Except that no surfactant 1 was added, a product containing F particles 1 (46.5 parts by mass), surfactant 2 (3.2 parts by mass), cellulose ether 1 (0.3 parts by mass) and water (50.0 parts by mass) was obtained in the same manner as in Example 1. mass parts) dispersion 3.

[Example 4] Except that cellulose ether 2 is used to replace cellulose ether 1, a product containing F particles 1 (46.5 parts by mass), surfactant 1 (0.9 parts by mass), surfactant 2 (2.3 parts by mass) is obtained in the same manner as in Example 1 ), cellulose ether 2 (0.3 parts by mass) and water (50.0 parts by mass) dispersion 4. [Example 5] Except that F particles 2 are used instead of F particles 1, a product containing F particles 2 (46.5 parts by mass), surfactant 1 (0.9 parts by mass), surfactant 2 (2.3 parts by mass), Dispersion 5 of cellulose ether 1 (0.3 parts by mass) and water (50.0 parts by mass). [Example 6] Except that cellulose ether 3 is used to replace cellulose ether 1, a preparation containing F particles 1 (46.5 parts by mass), surfactant 1 (0.9 parts by mass), surfactant 2 (2.3 parts by mass) is obtained in the same manner as in Example 1 ), cellulose ether 3 (0.3 parts by mass) and water (50.0 parts by mass) dispersion 6.

3.Evaluation 3-1. Foaming properties and dispersion stability of dispersion liquid Take 50 ml of each dispersion and put it into a 100 ml transparent container. Shake the transparent container up and down 10 times and let it stand for 10 minutes. Visually check the foaming state after 10 minutes, and further visually check whether components have settled after 7 days of storage, and evaluate based on the following criteria. ＜Evaluation Criteria＞ A: The bubbles will disappear just by letting them stand, and the components will not settle and are well dispersed even after storage. B1: Bubbles disappear when left alone. Although some components settle after storage, they can be easily redispersed. B2: Foaming can be removed by depressurizing and defoaming after standing. In addition, the components do not settle after storage, but are well dispersed. C: There is foaming. Even if it is left to stand and defoamed under reduced pressure, it is difficult to defoaming, and there is sedimentation of components after storage.

3-2. Evaluation of fluidity of dispersion and production of laminate Through the roll-to-roll process, each dispersion was coated on the surface of the base material (polyimide film ("FG-100" manufactured by PI Advanced Materials Co., Ltd.: thickness 25µm) using the small-diameter gravure reverse method to form a coating layer. It is further heated and fired to obtain a laminate with polymer layers (thickness 25µm) on both sides of the base material. At this time, the surface of the coating layer is visually observed for blisters and textures, and evaluated based on the following criteria. ＜Evaluation criteria for coating surface＞ A: No bubbling at all, the surface is smooth and no texture is observed. B: No visible blistering, the surface is smooth but random texture is observed C: There is visible bubbling and texture is observed The above results are summarized in Table 1.

[Table 1]

industrial availability The dispersion liquid of the present invention has excellent dispersion stability and handling properties. Furthermore, a molded article can be formed into a coating film (polymer layer) that highly exhibits the physical properties of the F polymer, especially a coating film (polymer layer) excellent in surface appearance.

In addition, the entire contents of the specification, patent scope and abstract of Japanese Patent Application No. 2022-094392 filed on June 10, 2022 are quoted here and incorporated into the disclosure of the specification of the present invention.

(without)

Claims (15)

A dispersion liquid containing: particles of a tetrafluoroethylene polymer, a nonionic surfactant, a cellulose ether with a degree of substitution of 1.4 or more, and water. Such as the dispersion liquid of claim 1, wherein the average particle diameter of the particles of the aforementioned tetrafluoroethylene polymer is 1 μm or more and less than 10 μm, and the specific surface area is 1~25 m ² /g. The dispersion liquid of claim 1, wherein the content of the particles of the aforementioned tetrafluoroethylene polymer is greater than 30% by mass. The dispersion of claim 1, wherein the tetrafluoroethylene polymer is a tetrafluoroethylene polymer having a carbonyl-containing group. For example, the dispersion liquid of claim 4 has 100 to 3000 carbonyl-containing groups per 1×10 ⁶ main chain carbon number of the tetrafluoroethylene polymer. The dispersion liquid of claim 1 contains an alcoholic surfactant with an HLB value of less than 10 as the aforementioned nonionic surfactant. The dispersion liquid of claim 1 contains a nonionic surfactant with an HLB value of 10 or more as the nonionic surfactant. For example, the dispersion liquid of claim 1 contains an alcohol-based surfactant with an HLB value of less than 10 and a polysiloxane-based surfactant with an HLB value of 10 or more as the aforementioned nonionic surfactant. The dispersion liquid of claim 1, wherein the content of the nonionic surfactant is 1 to 15% by mass relative to the content of the particles. Such as the dispersion of claim 1, wherein the substitution degree of the aforementioned cellulose ether is 1.9~2.9. The dispersion of claim 1, wherein the aforementioned cellulose ether is carboxyalkyl cellulose, hydroxyalkyl cellulose or hydroxyalkyl alkyl cellulose. The dispersion of claim 1, wherein the cellulose ether is hydroxyalkyl cellulose or hydroxyalkyl alkyl cellulose. Such as the dispersion liquid of claim 1, which further contains monoalcohols with 1 to 6 carbon atoms. The dispersion liquid of claim 1 further contains at least one selected from the group consisting of aromatic polymers and inorganic fillers. A method for manufacturing a laminated body, which is to arrange the dispersion liquid according to any one of claims 1 to 14 on the surface of a base material and heat it to form a polymer layer containing the above-mentioned tetrafluoroethylene polymer, thereby obtaining the above-mentioned properties in sequence. A laminate of a base material layer composed of a base material and the aforementioned polymer layer.