TW202235524A - Aqueous dispersion and method for producing same - Google Patents

Abstract

To provide an aqueous dispersion which contains particles of a tetrafluoroethylene polymer and exhibits excellent dispersion stability, while being capable of forming a molded body that is excellent in terms of electrical characteristics such as low dielectric loss tangent and low transmission loss, flexibility such as bending resistance, UV absorption, and bondability/adhesion to resin films such as polyimide films. An aqueous dispersion which contains particles of a tetrafluoroethylene polymer, an aromatic imide resin that has an acid value of from 20 mg/KOH to 100 mg/KOH, and water, and which has a pH of from 5 to 10.

Description

Aqueous dispersion liquid and its production method

The present invention relates to an aqueous dispersion comprising tetrafluoroethylene polymer particles and a specific aromatic imide resin, and a method for producing the aqueous dispersion.

Tetrafluoroethylene-based polymers such as polytetrafluoroethylene (PTFE) are excellent in physical properties such as electrical properties, water and oil repellency, chemical resistance, and heat resistance, and are used in various industrial applications (Patent Document 1). A dispersion containing tetrafluoroethylene-based polymer particles is known as a coating agent for imparting the above-mentioned physical properties to the surface of a substrate. In particular, in recent years, dispersions containing tetrafluoroethylene-based polymer particles have attracted attention as materials with excellent electrical properties such as low dielectric constant and low dielectric loss factor that form the dielectric layer of printed circuit boards corresponding to high-band frequencies. .

From the viewpoint of workability, it is preferable to make the above-mentioned dispersion liquid into an aqueous system. Patent Document 2 discloses a laminate formed by applying an aqueous dispersion of a fluororesin to one or both sides of a resin film and heating it. Patent Document 3 discloses a composition comprising an aqueous polyimide precursor, a fluororesin, and water, and these are uniformly mixed. prior art literature patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2019-218484 Patent Document 2: Japanese Patent Laid-Open No. 09-157418 Patent Document 3: Japanese Patent Laid-Open No. 2016-20488

[Problem to be solved by the invention]

However, the dispersion state of an aqueous dispersion of a tetrafluoroethylene polymer is generally inferior to that of a non-aqueous dispersion. Therefore, during the coating and firing of the base material, the filling property of the tetrafluoroethylene polymer particles becomes loose, and the compactness of the formed polymer layer tends to cause problems. Specifically, if the polymer layer is formed on a base material such as a resin film by a continuous production process such as roll to roll, cracks or pinholes are likely to occur in the polymer layer. According to the research of the inventors of the present invention, these tendencies become remarkable when the aqueous dispersion liquid of the prior art document is used.

The inventors of the present invention conducted intensive studies and found that a dispersion containing tetrafluoroethylene-based polymer particles, a specific aromatic imide-based resin, and water and having a pH within a specific range has excellent dispersion stability. . In addition, it was found that the molded article obtained from the dispersion liquid is relatively dense, has excellent low dielectric loss factor and low linear expansion coefficient, and has flexibility such as flex resistance, UV (Ultraviolet, ultraviolet) absorption, and polyamide The adhesion and adhesion of plastic films such as amine films are improved. The object of the present invention is to provide an aqueous dispersion that is excellent in dispersion stability, and the molded product obtained has flexibility such as flex resistance, UV absorption, and adhesiveness and adhesion to resin films such as polyimide films. excellent. [Technical means to solve the problem]

The present invention has the following aspects. <1> An aqueous dispersion comprising tetrafluoroethylene polymer particles, an aromatic imide resin having an acid value of 20-100 mg/KOH, and water, and having a pH of 5-10. <2> The aqueous dispersion according to <1>, wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having an oxygen-containing polar group including a perfluoro(alkyl vinyl ether)-based unit. <3> The aqueous dispersion according to <1> or <2>, wherein the tetrafluoroethylene-based polymer particles include non-heat-fusible tetrafluoroethylene-based polymer particles and heat-fusible tetrafluoroethylene-based polymer particles. <4> The aqueous dispersion according to any one of <1> to <3>, wherein the aromatic imide-based resin is a water-soluble aromatic polyimide precursor or a water-soluble aromatic polyimide Imine precursors. <5> The aqueous dispersion according to any one of <1> to <4>, which further contains an inorganic filler. <6> The aqueous dispersion according to any one of <1> to <5>, which further contains a nonionic surfactant. <7> The aqueous dispersion according to any one of <1> to <6>, further comprising at least one selected from the group consisting of polyvinyl alcohol-based polymers, polyvinylpyrrolidone-based polymers, and polysaccharides. 1 kind of nonionic polymer. <8> The aqueous dispersion according to any one of <1> to <7>, which contains amine or ammonia. <9> The aqueous dispersion according to any one of <1> to <8>, wherein the ratio of the mass of the aromatic imide resin to the mass of the tetrafluoroethylene polymer particles is 0.001 to 0.1 scope. <10> The aqueous dispersion according to any one of <1> to <9>, wherein the total content of the particles and the aromatic imide-based resin in the aqueous dispersion is relative to the total mass of the aqueous dispersion 20% by mass or more. <11> The aqueous dispersion according to any one of <1> to <10>, which has a viscosity of 50 to 3000 mPa·s. <12> The aqueous dispersion according to any one of <1> to <11>, which is used to form a polymer layer containing a tetrafluoroethylene-based polymer by applying to at least one surface of a resin film and heating. <13> The aqueous dispersion according to any one of <1> to <12>, wherein the resin constituting the resin film is a polyimide-based resin. <14> A method for producing an aqueous dispersion, which is the method for producing an aqueous dispersion according to any one of <1> to <13>, comprising the above-mentioned tetrafluoroethylene-based polymer particles, the above-mentioned aromatic imide A composition of resin and water is kneaded to obtain a kneaded product, and the kneaded product is mixed with water to obtain the above-mentioned aqueous dispersion. <15> A laminate in which the aqueous dispersion according to any one of <1> to <13> is applied to both surfaces of a resin film and heated to form the above-mentioned polymer containing a tetrafluoroethylene-based polymer A layer having the above-mentioned polymer layer on both sides of the substrate layer including the above-mentioned resin film. [Effect of Invention]

According to the present invention, there can be provided an aqueous dispersion of a tetrafluoroethylene-based polymer excellent in dispersion stability, and a method for producing the aqueous dispersion. The aqueous dispersion of the present invention can form a molded article having excellent physical properties such as low dielectric loss factor and low transmission loss, etc., and flexibility such as flex resistance, UV absorbability, and polymeric properties. Excellent adhesion and adhesion of resin films such as imide films. Therefore, the aqueous dispersion of the present invention can be used, for example, as a constituent material of a printed circuit board.

The following terms have the following meanings. "Average particle diameter (D50)" is the volume-based cumulative 50% diameter of the object (particles and fillers) obtained by the laser diffraction-scattering method. That is, it measures the particle size distribution by the laser diffraction-scattering method, sets the total volume of the clusters of objects (particles and fillers) as 100% to obtain the cumulative curve, and the cumulative volume on the cumulative curve is 50%. The particle size of the point. The D50 of the object (particles and fillers) is obtained by dispersing the objects (particles and fillers) in water and using a laser diffraction-scattering particle size distribution measuring device (manufactured by Horiba, LA-920 measuring device) It can be obtained by analyzing the radiation diffraction-scattering method. The "melting temperature" is the temperature corresponding to the maximum value of the melting peak of the polymer measured by differential scanning calorimetry (DSC) method. "Viscosity" is obtained by measuring the object (dispersion and kneaded product) using a B-type viscometer at 25°C and 30 rpm. The measurement was repeated 3 times, and the average value of the 3 measurements was used. "Thixotropic ratio" is to divide the viscosity η ₁ of the object (dispersion and kneading) measured at a rotation speed of 30 rpm by the viscosity of the object (dispersion and kneading) at a rotation speed of 60 rpm The value calculated from the viscosity η ₂ measured under the conditions. The measurement of each viscosity was repeated 3 times, and the average value of the 3 measurements was adopted. "HLB (Hydrophile Lipophile Balance, hydrophilic/oil ratio) value of polyoxyalkylene-modified polydimethylsiloxane" is the value calculated by Griffin's formula, which is the polyoxyalkylene part in the molecule The molecular weight divided by the molecular weight of the organopolysiloxane was multiplied by 20 to obtain it. "Static surface tension" is obtained by Wilhelmy method using an automatic surface tensiometer CBVP-Z type (manufactured by Kyowa Interface Science Co., Ltd.) using a 0.1% by mass aqueous solution of polyoxyalkylene-modified polydimethylsiloxane out. "Dynamic surface tension" refers to the dynamic surface tension of a 0.1% by mass aqueous solution of polyoxyalkylene-modified polydimethylsiloxane at 25°C at a bubble generation period of 6 Hz by the maximum bubble pressure method. Under the environment of 25°C, the sensor of the dynamic surface tensiometer SITA t60 manufactured by Yinghong Seiki Co., Ltd. was immersed in the aqueous solution, and the modified polyoxyalkylene group was modified at a ratio of 0.1 mass % by the maximum bubble pressure method. The value obtained by measuring the dynamic surface tension of an aqueous solution of polydimethylsiloxane. The measurement was carried out by setting the bubble generation period of the aqueous solution to 6 Hz. The "unit" in a polymer means an atomic group based on the above-mentioned monomer formed by polymerization of the monomer. The unit may be a unit directly formed by a polymerization reaction, or may be a unit obtained by converting a part of the above unit into another structure by treating a polymer. Hereinafter, the unit based on monomer a is simply described as "monomer a unit".

The aqueous dispersion of the present invention (hereinafter also referred to as "this dispersion") comprises tetrafluoroethylene polymer (hereinafter also referred to as "F polymer") particles (hereinafter also referred to as "F particles"), Aromatic imide-based resin having an acid value of 20-100 mg/KOH (hereinafter, also referred to as "imide-based resin P") and water have a pH of 5-10.

This dispersion liquid has excellent dispersion stability. In addition, the molded article (baked article) formed from this dispersion liquid has excellent physical properties based on tetrafluoroethylene-based polymers such as electrical properties, excellent surface smoothness, and flexibility such as flex resistance, UV absorption, and polyamide Adhesiveness and adhesion of resin films such as imide films are also excellent. The reason why the dispersion stability of the present dispersion liquid is improved is not necessarily clear, but it can be estimated as follows, for example. It is considered that since the imide resin P in the present invention has a specific acid value, it is easy to interact with F particles and water, and it not only functions as a dispersant for F particles in this dispersion, but also acts as a dispersant for this dispersion. The viscosity modifier plays a role in improving the dispersion stability of the dispersion. Moreover, this dispersion liquid has a pH value within a specific range, not only to enhance this effect, but also to increase the reactivity of the imide-based resin P when this dispersion liquid is further heated to form a molded product. As a result, it is considered that the interaction between the imide-based resin P and the F polymer or the substrate is improved, and the flexibility, adhesiveness, and adhesion (adhesive ability) of the obtained molded product are improved. As a result, it is considered that this dispersion liquid has excellent dispersion stability, and it is possible to form a molded product with excellent electrical properties, flex resistance, UV absorption, etc. from this dispersion liquid by a continuous production process such as roll-to-roll.

The F polymer in this dispersion is a polymer comprising tetrafluoroethylene (TFE)-based units (TFE units). One type of F polymer may be used, or two or more types may be used. The F polymers may be thermally fusible or non-thermally fusible, but at least one of the F polymers is preferably thermally fusible. In this case, the molded article formed from this dispersion liquid tends to be excellent in flexibility, adhesiveness and adhesion to resin films such as polyimide films. Furthermore, the hot melt property means that under the condition of a load of 49 N, at a temperature higher than the melting temperature of the polymer by 20°C or more, there is a melt flow rate at a temperature of 0.1 to 1000 g/10 minutes. polymer. When the polymer F is thermally fusible, the melting temperature is preferably from 200 to 320°C, more preferably from 260 to 320°C. In this case, the heat resistance of the molded article formed from this dispersion liquid tends to become excellent.

The fluorine atom content in the F polymer is preferably at least 70% by mass, more preferably 70 to 76% by mass. The dispersion liquid is particularly easy to improve the water dispersibility of the F polymer particles with higher fluorine atom content through the above-mentioned action mechanism. The glass transition point of polymer F is preferably from 75 to 125°C, more preferably from 80 to 100°C.

Examples of the F polymer include: polytetrafluoroethylene (PTFE), a polymer containing TFE units and ethylene-based units (ETFE), a polymer containing TFE units and perfluoro(alkyl vinyl ether) (PAVE)-based Polymers (PFA) of units (PAVE units), polymers (FEP) comprising TFE units and units based on hexafluoropropylene (HFP). Each of ETFE, PFA and FEP may further comprise other units as well. As PAVE, CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ and CF ₂ =CFOCF ₂ CF ₂ CF ₃ (PPVE) are preferable, and PPVE is more preferable. The F polymer is preferably PFA or FEP, more preferably PFA.

Preferably, at least one of the F polymers has an oxygen-containing polar group. In this case, since the affinity of F polymer, imide resin P, and water improves, this dispersion liquid is easy to disperse and is excellent in stability. Also, in this case, it is considered that when the dispersion liquid is fired, the F polymer reacts with the imide resin P to form a crosslink, and as a result, the fired product (polymer layer, etc.) obtained from the dispersion liquid Physical properties such as electrical characteristics, surface smoothness, adhesion and adhesion to resin films such as polyimide films are more excellent. The oxygen-containing polar group may be included in the unit of the F polymer, or may be included in the terminal group of the main chain of the F polymer. As the latter aspect, for example: F polymer having an oxygen-containing polar group as a terminal group derived from a polymerization initiator, a chain transfer agent, etc.; F polymer having a plasma treatment or ionizing radiation treatment F polymers containing oxygen polar groups. The oxygen-containing polar group is preferably a hydroxyl-containing group, a carbonyl-containing group, and a phosphonyl-containing group, and is more preferably a hydroxyl-containing group or a carbonyl-containing group from the viewpoint of dispersion stability of the dispersion. Further preferred is a group containing a carbonyl group.

The hydroxyl-containing group is preferably a group containing an alcoholic hydroxyl group, more preferably -CF ₂ CH ₂ OH, -C(CF ₃ ) ₂ OH and 1,2-ethylene glycol (-CH(OH)CH ₂ OH ). The carbonyl-containing group is a group containing a carbonyl group (>C(O)), preferably a carboxyl group, an alkoxycarbonyl group, an amido group, an isocyanate group, a carbamate group (-OC(O)NH ₂ ), anhydride residues (-C(O)OC(O)-), imide residues (-C(O)NHC(O)-, etc.) and carbonate groups (-OC(O)O-), More preferred is an acid anhydride residue. When the F polymer has a carbonyl-containing group, the number of carbonyl-containing groups in the F polymer is preferably 10 to 5,000 per 1×10 ⁶ carbons in the main chain, more preferably 100 to 3,000 , more preferably 800 to 1500. Furthermore, the number of carbonyl-containing groups in the F polymer can be quantified by the composition of the polymer or the method described in International Publication No. 2020/145133.

As the F polymer, it is preferably a polymer with an oxygen-containing polar group comprising a TFE unit and a PAVE unit, more preferably a polymer comprising a TFE unit, a PAVE unit, and a unit based on a monomer with an oxygen-containing polar group, and then Preferably, it is a polymer containing 90 to 99 mol%, 0.5 to 9.97 mol%, and 0.01 to 3 mol% of these units sequentially relative to all units. Also, the monomer having an oxygen-containing polar group is preferably itaconic anhydride, citraconic anhydride, or 5-northene-2,3-dicarboxylic anhydride (hereinafter also referred to as "NAH"). Specific examples of the polymer include polymers described in International Publication No. 2018/16644. These F polymers are not only excellent in the dispersion stability of the particles, but also tend to be denser and more uniformly distributed in molded products (polymer layers, etc.) obtained from this dispersion. Furthermore, micro-spherulites are easily formed in the molded product, and the adhesiveness with other components tends to be high. As a result, it becomes easier to obtain a molded article excellent in various physical properties such as electrical characteristics.

The non-thermofusible F polymer may, for example, be non-thermofusible PTFE. The number average molecular weight of the non-thermofusible PTFE is preferably 1 million to 100 million. In addition, the number average molecular weight of non-heat-fusible PTFE is the value calculated based on following formula (1). Mn=2.1×10 ¹⁰ ×ΔHc ^-5.16・・・ (1) In the formula (1), Mn represents the number average molecular weight of non-thermal melting PTFE, and ΔHc represents the non-thermal melting measured by differential scanning calorimetry Crystallization heat of PTFE (cal/g). When the number average molecular weight is within this range, the F polymer is less likely to be fibrillated, and the dispersion stability of the present dispersion is likely to be excellent.

In this dispersion, the D50 of the F particles is preferably 0.1-25 μm. The D50 of the F particles is preferably 20 μm or less, more preferably 10 μm or less, further preferably 8 μm or less. The D50 of the F particles is preferably at least 0.1 μm, more preferably at least 1 μm, and still more preferably at least 2 μm. In this range of D50, the fluidity and dispersibility of F particles tend to become better.

From the viewpoint of the dispersion stability of the present dispersion, the bulk density of the F particles is preferably at least 0.15 g/m ² , more preferably at least 0.20 g/m ² . The bulk density of F particles is preferably not more than 0.50 g/m ² , more preferably not more than 0.35 g/m ² . Also, the specific surface area of the F particles is preferably from 1 to 8 m ² /g, more preferably from 1 to 3 m ² /g.

One type of F particles may be used, or two or more types may be used. In the case of using two types of F particles, it is preferable to include non-heat-fusible F polymer particles and heat-fusible F polymer particles, more preferably to include non-heat-fusible PTFE (preferably the above-mentioned number average molecular weight is 1 million to 100 million PTFE) particles, and F polymer (preferably a polymer with oxygen-containing polar groups including the above TFE unit and PAVE unit) particles with a melting temperature of 200 to 320°C.

In this case, regarding the ratio of the contained mass of the two particles, the contained mass of the former particle may be greater than the contained mass of the latter particle, or the contained mass of the former particle may be less than the contained mass of the latter particle. Furthermore, it is more preferable that the contained mass of the former particle is larger than the contained mass of the latter particle. In this case, the ratio of the latter particles to the total of the former particles and the latter particles is preferably 25% by mass or less, more preferably 15% by mass or less. In addition, the ratio in this case is preferably at least 0.1% by mass, more preferably at least 1% by mass. This dispersion liquid not only tends to be excellent in dispersion stability, handleability, and long-term storage stability, but also easily forms a molded article based on PTFE with excellent physical properties and adhesive properties.

Also, when the content of the former particles is less than the content of the latter particles, it is preferable from the viewpoint of being easy to form a molded product having excellent adhesiveness and surface smoothness. In this case, the ratio of the former particles to the total of the former particles and the latter particles is preferably less than 50% by mass, more preferably 25% by mass or less. Moreover, the said ratio is preferably 5 mass % or more, More preferably, it is 10 mass % or more.

When using non-thermally fusible F polymer particles and F polymer particles with a melting temperature of 200-320°C, it is preferable that the D50 of the non-thermally fusible PTFE particles is 0.1-1 μm and the melting temperature is 200-320°C. The D50 of F polymer particles at 320°C is 0.1-1 μm, and the D50 of F polymer particles with non-heat-melting PTFE particles is 0.1-1 μm and the melting temperature is 200-320°C. The D50 of F polymer particles is 1-1 4 μm pattern.

The F particles may also contain resins or inorganic fillers other than the F polymer, preferably the F polymer as the main component. The content of the F polymer in the F particles is preferably at least 80% by mass, more preferably 100% by mass. Examples of the aforementioned resins include aromatic polyesters, polyamideimides, (thermoplastic) polyimides, polyphenyl ethers, polyphenylene oxides, and maleimides. Heat-resistant resins such as amines. Examples of inorganic fillers include silicon oxide (silica), metal oxides (beryllium oxide, cerium oxide, aluminum oxide, alkali aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, etc.), boron nitride, and magnesium metasilicate. (block talc). The inorganic filler may be surface-treated on at least a part of its surface. The F particles containing resins or inorganic fillers other than F polymers have a core-shell structure containing F polymers as cores and resins other than F polymers or inorganic fillers as shells, or may also have F particles containing F polymers as shells. Shell, core-shell structure containing resin other than F polymer or inorganic filler as core. The F particles can be obtained, for example, by coagulating (collision, aggregation, etc.) the F polymer particles with resins other than the F polymer or inorganic filler particles.

The imide-based resin P constituting this dispersion enhances the dispersion stability of this dispersion, and imparts flexibility such as flex resistance and UV absorption to molded articles obtained from this dispersion. In addition, when the dispersion liquid is applied to the surface of a resin film such as a polyimide film to form a polymer layer containing the F polymer, properties such as adhesiveness and adhesion to the resin film are imparted to the polymer layer.

As the imide-based resin P, aromatic polyimide, aromatic polyimide precursor (polyamic acid or its salt), aromatic polyamide imide, aromatic polyimide Aminoimide precursors, modified aromatic polyimides with polar functional groups such as carboxylic acid groups, modified aromatic polyimide precursors, modified aromatic polyamideimides, modified aromatic An aromatic polyamideimide precursor, an aromatic polyetherimide or an aromatic polyetherimide precursor. Among them, aromatic polyimide or its precursor (polyamic acid or its salt), aromatic polyamide imide or its precursor are preferred, more preferably water-soluble aromatic polyimide precursor A substance, a water-soluble aromatic polyamide imide precursor, and more preferably a water-soluble aromatic polyamide imide precursor.

Examples of water-soluble aromatic polyimide precursors include polyamic acid obtained by polymerizing tetracarboxylic dianhydride and diamine in a solvent, or reacting polyamic acid with ammonia or organic amine Made of polyamic acid salt. An aqueous solution of polyamic acid can be prepared by dissolving polyamic acid salt in water. As a tetracarboxylic dianhydride, a pyromellitic anhydride and a biphenyltetracarboxylic anhydride are mentioned, for example. As a diamine, N,N'- diamino diphenyl ether and p-diaminobenzene are mentioned, for example. As a solvent, N-methylpyrrolidone and N,N- dimethylformamide are mentioned, for example. As organic amines, for example, primary amines such as methylamine, ethylamine, n-propylamine, 2-ethanolamine, 2-amino-2-methyl-1-propanol, etc.; dimethylamine, 2- Secondary amines such as (methylamino)ethanol and 2-(ethylamino)ethanol; 2-dimethylaminoethanol, 2-diethylaminoethanol, 1-dimethylamino-2-propanol, etc. Tertiary amines; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide.

Examples of water-soluble aromatic polyamideimide resins or their precursors include polyamides obtained by reacting diisocyanates and/or diamines with tribasic anhydrides (or tribasic acid chlorides) as acid components. Aminoimide resin or its precursor. Examples of diisocyanates include: 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 3,3 '-Diphenylmethane diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, p-phenylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, naphthalene diisocyanate, toluene Diisocyanate, isophorone diisocyanate. These diisocyanates may be used alone or in combination of two or more. Furthermore, from the viewpoint of improving the stability of the aromatic polyamideimide resin, as the diisocyanate, a blocked isocyanate obtained by stabilizing isocyanate groups with a blocking agent can also be used. As a blocking agent, alcohol, phenol, an oxime, etc. are mentioned.

Examples of diamines include: 3,3'-dimethylbiphenyl-4,4'-diamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl Ether, 4,4'-diaminodiphenylene, 3,3'-diaminodiphenylene, xylylenediamine, phenylenediamine, isophoronediamine. These diamines may be used individually by 1 type, and may use it in combination of 2 or more types.

Tribasic acid anhydrides include, for example, trimellitic anhydride, and examples of tribasic acid chlorides include trimellitic anhydride chloride. As the tribasic acid anhydride, trimellitic anhydride is preferred from the viewpoint of reducing the load on the environment.

When producing aromatic polyamide imide resins, in addition to the above-mentioned tribasic acid anhydrides (or tribasic acid chlorides), dicarboxylic acids can also be used as acid components within the range that does not impair the properties of polyamide imide resins. acid, tetracarboxylic dianhydride, etc. As the dicarboxylic acid, for example, terephthalic acid, isophthalic acid, adipic acid, and sebacic acid may be mentioned. As a tetracarboxylic dianhydride, a pyromellitic dianhydride, a benzophenone tetracarboxylic dianhydride, and biphenyltetracarboxylic dianhydride are mentioned, for example. These may be used alone or in combination of two or more. Regarding the total amount of carboxylic acids (dicarboxylic acids and tetracarboxylic acids) other than tribasic acids, it is preferably 0 to 30 moles of the total carboxylic acids from the viewpoint of maintaining the characteristics of the polyamide imide resin. ear % range.

Regarding the use ratio of diisocyanate and/or diamine to acid component (the total amount of tribasic acid anhydride or tribasic anhydride amide chloride and optional dicarboxylic acid and tetracarboxylic dianhydride), the resulting polyamide From the viewpoint of the molecular weight of the imide resin and the degree of crosslinking, it is preferable to set the diisocyanate compound and/or the diamine compound at 0.8 to 1.1 mole relative to the total amount of the acid component of 1.0 mole, more preferably It is 0.95-1.08 mol, More preferably, it is 1.0-1.08 mol.

The water-soluble aromatic polyamideimide resin or its precursor can be obtained by copolymerizing the above-mentioned diisocyanate and/or diamine and the above-mentioned acid component in a polar solvent. Examples of polar solvents include: N-methyl-2-pyrrolidone, N-formylmethanol, N-acetylylurea, N,N'-dimethylethyleneurea, N,N- Dimethylacetamide, N,N-dimethylformamide, γ-butyrolactone, etc. From the viewpoint of carrying out the imidization reaction at high temperature for a short time, a solvent with a high boiling point is preferable, and N-methyl-2-pyrrolidone is usually used from the viewpoint of solubility. From the viewpoint of work environment and easiness of safety management, N-formyl ?? The amount of polar solvent used is usually 50 to 500 parts by mass relative to 100 parts by mass of the total amount of diisocyanate or diamine and acid component, depending on the solubility of the obtained aromatic polyamide imide resin or its precursor Viewpoint is better. The polymerization temperature is usually in the range of 80 to 180°C, and in order to reduce the influence of moisture in the air, it is preferably carried out under an atmosphere of nitrogen or the like.

The water-soluble aromatic polyamideimide resin or its precursor can be produced, for example, by the following methods: (1) a method of using an acid component, and a diisocyanate component and/or a diamine component at one time and reacting them; (2) The acid component is reacted with excess diisocyanate component and/or diamine component to synthesize an amidoimide oligomer having an isocyanate group or an amine group at the end, and then an acid component is added, and the isocyanate at the end is A method of reacting cyanate groups and/or amine groups; (3) after reacting excess acid components with diisocyanate components and/or diamine components to synthesize amidoimide oligomers with acid or anhydride groups at the end , A method in which diisocyanate components and/or diamine components are added to react with terminal acid or anhydride groups.

The number average molecular weight (Mn) of the water-soluble aromatic polyamideimide resin or its precursor is preferably at least 5,000, more preferably at least 10,000, and still more preferably at least 15,000. On the other hand, Mn is preferably 50000 or less, more preferably 30000 or less, still more preferably 25000 or less. When Mn is within this range, mechanical properties such as the solubility of the aromatic polyamideimide resin or its precursor in water, and the flex resistance of the molded article obtained from the dispersion can be ensured. Furthermore, regarding the Mn of the aromatic polyamideimide resin or its precursor, the reaction solution is appropriately sampled during polymerization, and measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve, Polymerization is performed until it becomes the target Mn, and thereby it can be managed within the above-mentioned range.

Examples of aromatic polyetherimides include: amorphous polymers having imide bonds and ether bonds in the main chain, preferably 2,2-bis[4-(3,4-dicarboxybenzene The condensation polymer of oxy)phenyl]propane and m-phenylenediamine. As a commercial item of aromatic polyether imide, "Ultem 1000F3SP" (made by SABIC company) is mentioned, for example.

The acid value of imide resin P is 20-100 mg/KOH. In this dispersion liquid, the function is balanced by adjusting the acid value of the imide resin P within this range. That is, if the acid value of the imide resin P is less than 20 mg/KOH, when the molded product is formed from the dispersion, the reaction rate of the imide resin P is improved, and the physical properties of the molded product are improved. On the one hand, its dispersing effect is reduced, resulting in a reduction in the dispersion stability of the dispersion. Also, if the acid value of the imide resin P exceeds 100 mg/KOH, the dispersion of the imide resin P in the dispersion is improved. On the other hand, when forming a molded product from the dispersion, the imide The reaction rate of the amine resin P decreases, resulting in a decrease in the physical properties of the molded product. Furthermore, specifically, if the acid value is 20 mgKOH/g or more, since there are many acidic groups, the imide resin P tends to dissolve in water easily, and the imide resin P and F particles and water The tendency to interact easily means that the adhesiveness between the molded article formed from this dispersion and the base material tends to be excellent. Moreover, there exists a tendency for the storage stability of this dispersion liquid to improve that an acid value is 100 mgKOH/g or less. Also, from these viewpoints, the acid value of the imide resin P is preferably 35 to 70 mgKOH/g. In addition, when imide-type resin P has an acid anhydride group, the acid value at the time of ring-opening an acid anhydride group is made into the acid value of imide-type resin P.

Regarding the above acid value, collect about 0.5 g of imide resin P, add about 0.15 g of 1,4-diazabicyclo[2.2.2]octane, and then add about 60 g of N-methyl - 2-pyrrolidone and about 1 ml of ion-exchanged water, stirred until the imide-based resin P is completely dissolved. The acid value can be determined by titrating with a potentiometric titration device using 0.05 mol/L ethanolic potassium hydroxide solution.

Preferable specific examples of the imide-based resin P include "HPC-1000" and "HPC-2100D" (both are manufactured by Showa Denko Materials).

The content of the F particles in the dispersion is preferably at least 10% by mass, more preferably at least 25% by mass, based on the total mass of the dispersion. The content of the F particles is preferably at most 80% by mass, more preferably at most 70% by mass, based on the total mass of the dispersion. The content of the imide-based resin P in the dispersion is preferably at least 0.1% by mass, more preferably at least 0.3% by mass, based on the overall mass of the dispersion. The content of the imide resin P is preferably at most 30% by mass, more preferably at most 10% by mass.

The total content of F particles and imide-based resin P in this dispersion is preferably 20% by mass or more with respect to the overall mass of this dispersion. The above-mentioned total content is more preferably at least 30% by mass, further preferably at least 40% by mass. The above-mentioned total content is preferably at most 80% by mass. As a specific example of the preferable range of the said total content, 30-80 mass % is mentioned. In this case, molded articles such as a coating film can be formed with high uniformity from this dispersion liquid, and the physical properties obtained from the F polymer and the physical properties obtained from the imide-based resin P can easily be highly expressed. That is, even if the content of the polymer component is within the relatively high range, the dispersion liquid can achieve excellent dispersion stability and improve the physical properties of its molded product through the above-mentioned action mechanism.

Also, the ratio of the mass of the imide-based resin P to the mass of the F particles in the dispersion is preferably 0.001 or more, more preferably 0.005 or more, and still more preferably 0.01 or more. The above-mentioned ratio is preferably at most 0.1, more preferably at most 0.09, still more preferably at most 0.05. As a specific example of the preferable range of the said ratio, 0.001-0.1 is mentioned. If the above-mentioned ratio is within the lower range, the dispersion stability of the F particles is improved, and the physical properties of the molded article obtained from this dispersion liquid are particularly likely to be improved. Although the reason is not necessarily clear, it is believed that the reason is that the acid value of the imide resin P and the pH value of the aqueous dispersion are in a specific range, and the imide resin P is a small amount of components relative to the F particles. In the solution, the imide resin P is easy to function as a dispersant for low-hydrophilic F particles and functions highly as a binder. Densified calcination of particles.

The content of water in this dispersion is preferably at least 40% by mass, more preferably at least 50% by mass. The water content is preferably at most 90% by mass, more preferably at most 80% by mass. Within this range, the dispersion stability of the dispersion is more likely to be improved through the above-mentioned mechanism of action.

This dispersion liquid may further contain a water-soluble dispersion medium other than water as a dispersion medium. As the water-soluble dispersion medium, water-soluble compounds classified as polar under atmospheric pressure and liquid at 25°C are preferred, for example, N,N-dimethylformamide, N,N-dimethylformamide Acetamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N-methyl-2-pyrrolidone.

This dispersion liquid may further contain a surfactant. When the dispersion contains a surfactant, the surfactant is non-ionic, the hydrophobic part of the surfactant preferably has an ethynyl group or a polysiloxane group, and the hydrophilic part preferably has an oxyalkylene group or a polysiloxane group. Alcoholic hydroxyl. That is, when the dispersion further contains a surfactant, it is preferably a nonionic surfactant having an alcoholic hydroxyl group, more preferably a polyoxyalkylene alkyl ether, an acetylene-based surfactant, or a silicone Department of surfactants. These surfactants may be used alone or in combination of two or more. From the perspective of stabilizing the long-term dispersibility of F particles, improving the liquid physical properties such as the viscosity of this dispersion, and improving the initial dispersibility of F particles, it is preferable to use polyoxyalkylene alkyl ether and silicone together. Department of surfactants. When this dispersion liquid further contains a surfactant, its amount is preferably 1 to 15% by mass relative to the mass of this dispersion liquid as a whole. In this case, the affinity between the components is enhanced, and the dispersion stability of the present dispersion is more likely to be improved.

From the viewpoint of suppressing the load on the environment, and from the viewpoint of stability in the present dispersion, it is preferable that the weight average molecular weight of the silicone-based surfactant is 3000 or less, and it is calculated by Griffin's formula Polyoxyalkylene-modified polydimethylsiloxane with an HLB value of 1-18.

The above-mentioned polyoxyalkylene-modified polydimethylsiloxane (hereinafter, also referred to as "modified polydimethylsiloxane") has a polyoxyalkylene structure as a hydrophilic group and has a polydimethylsiloxane The siloxane structure is an organopolysiloxane with a hydrophobic group, preferably a linear polymer.

The weight average molecular weight of the modified polydimethylsiloxane is 3000 or less, preferably 2500 or less, more preferably 2000 or less. The weight average molecular weight is preferably at least 100, more preferably at least 500. The number average molecular weight of the modified polydimethylsiloxane is preferably 3000 or less, more preferably 1500 or less. The number average molecular weight is preferably at least 100, more preferably at least 500. The molecular weight dispersion of the modified polydimethylsiloxane is preferably not more than 2.0, more preferably not more than 1.8. The lower limit of the molecular weight dispersion is preferably more than 1.0.

The HLB value of the modified polydimethylsiloxane is 1 to 18, preferably 3 or more, more preferably 6 or more, further preferably 10 or more, especially preferably 12 or more. The HLB value is preferably 16 or less, more preferably 15 or less.

The static surface tension of the modified polydimethylsiloxane is preferably not more than 28 mN/m, more preferably not more than 26 mN/m. The static surface tension is preferably at least 15 mN/m, more preferably at least 20 mN/m. The dynamic surface tension of the modified polydimethylsiloxane is preferably 40 mN/m or less, more preferably 35 mN/m or less, and the dynamic surface tension is preferably 20 mN/m or more.

The modified polydimethylsiloxane can also have a dimethylsiloxane unit (-(CH ₃ ) ₂ SiO _2/2 -) in the main chain, or a dimethylsiloxane unit in the side chain, It is also possible to have a dimethylsiloxane unit in both the main chain and the side chain. The modified polydimethylsiloxane is preferably a modified polydimethylsiloxane containing dimethylsiloxane units in the main chain and having an oxyalkylene group in the side chain, or a modified polydimethylsiloxane containing dimethylsiloxane in the main chain. Modified polydimethylsiloxane with alkane unit and oxyalkylene group at the end of the main chain.

Specific examples of modified polydimethylsiloxane include: "BYK-347", "BYK-349", "BYK-378", "BYK-3450", "BYK-3451", "BYK -3455", "BYK-3456" (above, manufactured by BYK-Chemie Japan); "KF-6011", "KF-6043" (above, manufactured by Shin-Etsu Chemical Co., Ltd.).

The weight average molecular weight of the modified polydimethylsiloxane is small, and the HLB value is in a specific range, so it can be said that its hydrophobicity and hydrophilicity are highly balanced. It is considered that the interaction between the modified polydimethylsiloxane and the F particles tends to be enhanced, and as a result, it is considered that the dispersion stability of the present dispersion is improved. Also, since the modified dimethylsiloxane has excellent thermal decomposability, it is easily decomposed when the dispersion is heated to form a baked product. As a result, the calcined product tends to have high physical properties based on the F polymer.

The polyoxyalkylene alkyl ether is preferably polyoxyethylene decyl ether, polyoxyethylene undecyl ether, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene tetradecane Base ether, triethylene glycol monomethyl ether, polyethylene glycol trimethyl nonyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, Ethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, more preferably polyoxyethylene decyl ether , polyoxyethylene undecyl ether, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, or polyoxyethylene myristyl ether.

Polyoxyalkylene alkyl ethers are commercially available, and specifically, "Tergitol TMN-100X" (manufactured by The Dow Chemical Company); "Lutensol TO8", "Lutensol XL70", "Lutensol XL80", "Lutensol XL90", "Lutensol XP80", "Lutensol M5" (the above, manufactured by BASF); "Newcol 1305", "Newcol 1308FA", "Newcol 1310" (the above, manufactured by Nippon Emulsifier Co.); " LEOCOL TDN-90-80", "LEOCOL SC-90" (above, manufactured by Lion Specialty Chemicals).

When the present dispersion contains a surfactant, the polyoxyalkylene alkyl ether can be obtained as a commercial product, specifically, "Tergitol TMN-100X" (manufactured by The Dow Chemical Company); "Lutensol TO8". Also, when the present dispersion further contains a surfactant, the amount thereof is preferably at least 0.1% by mass, more preferably at least 0.1% by mass, based on the mass of the entire dispersion. Moreover, the above-mentioned amount is preferably 15% by mass or less.

The present dispersion may further contain at least one nonionic polymer selected from the group consisting of polyvinyl alcohol-based polymers, polyvinylpyrrolidone-based polymers, and polysaccharides. The nonionic polymer is most preferably a water-soluble polymer. In this case, through the interaction between the water-soluble polymer and the imide resin P, not only the dispersion stability of the dispersion is improved, but also the rheological properties are improved, and the film-forming properties of the dispersion are improved. Etc. operability can be improved easily. As a result, it becomes easier to form a thick molded product or a molded product of any shape obtained from the dispersion. In particular, when the above-mentioned water-soluble polymer has a nonionic hydroxyl group, this tendency tends to become conspicuous. The polyvinyl alcohol-based polymer can be polyvinyl alcohol obtained by partial acetylation or partial acetalization. Examples of polysaccharides include glycogen, pullulan, dextrin, dextran, fructan, chitin, amylose, agarose, pullulan, and cellulose. The celluloses may, for example, be methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose or hydroxypropylcellulose.

The water-soluble nonionic polymer is preferably a nonionic polysaccharide, more preferably a nonionic cellulose, and further preferably a hydroxymethylcellulose, hydroxyethylcellulose or hydroxypropylcellulose. Specific examples of the nonionic polysaccharides include: "Sunrose (registered trademark)" series (manufactured by Nippon Paper Co., Ltd.), "Metolose (registered trademark)" series (manufactured by Shin-Etsu Chemical Co., Ltd.), "HEC CF grade" (manufactured by Sumitomo Seika Chemical Co., Ltd.).

Also, when the present dispersion further contains a water-soluble nonionic polymer, the amount thereof is preferably at least 0.01% by mass, more preferably at least 0.1% by mass, based on the mass of the entire dispersion. Moreover, it is preferable that the said amount is less than 1 mass %. The ratio of the mass of the water-soluble nonionic polymer in the present dispersion to the mass of the F particles is preferably at least 0.001, more preferably at least 0.01. Moreover, the above-mentioned ratio is preferably less than 0.1. As mentioned above, through the interaction between the water-soluble polymer and the imide resin P, the effect of improving the liquid physical properties and film-forming properties of the present dispersion obtained by containing the water-soluble polymer in a small amount is easily obtained. As a result, the residual amount of the above-mentioned water-soluble polymer in the molded article obtained from the present dispersion is reduced, and a molded article having more excellent physical properties such as electrical characteristics can be easily obtained from the present dispersion. This tendency is remarkable especially when the said water-soluble polymer has a nonionic hydroxyl group.

The present dispersion liquid may further contain amine or ammonia. It is considered that amine or ammonia also functions as a pH adjuster and contributes to improving the dispersion stability or storage stability of the dispersion. When the present dispersion liquid further contains amine or ammonia, the amount thereof may be such that the pH value of the present dispersion liquid is 5-10.

The amine may, for example, be dimethylamine, diethylamine, diisopropylamine, diethanolamine, triethanolamine, tripranolamine, triethylamine, tripentylamine, pyridine or N-methylmethanolamine. In this case, a pH buffering agent may be further added to stabilize the pH of the liquid composition. Examples of the pH buffering agent include tris(hydroxymethyl)aminomethane, ethylenediaminetetraacetic acid, ammonium bicarbonate, ammonium carbonate, and ammonium acetate.

From the viewpoint of improving the adhesiveness and low linear expansion of the molded article formed from this dispersion, this dispersion may further contain resin materials other than F polymer and imide resin P. The resin material can be thermosetting, or thermoplastic, or modified, and can be dissolved in the dispersion, or dispersed without being dissolved. Examples of such resin materials include acrylic resins, phenolic resins, liquid crystalline polyesters, liquid crystalline polyesteramides, polyolefin resins, modified polyphenylene ethers, polyfunctional cyanate resins, and polyfunctional maleic acid resins. Diimide-cyanate resin, polyfunctional maleimide, aromatic elastomer such as styrene elastomer, vinyl ester resin, urea resin, diallyl phthalate resin, Melamine resin, guanamine resin, melamine-urea co-condensation resin, polycarbonate, polyarylate, polyarylene, polyarylene, aromatic polyamide, aromatic polyetheramide, polyphenylene sulfide, polyarylether Ketones, polyphenylene ethers, epoxy resins, etc. When this dispersion liquid further contains a resin material, its content is preferably 40% by mass or less with respect to the mass of this dispersion liquid as a whole.

As a preferable aspect of a resin material, an aromatic polymer is mentioned. The aromatic polymer is preferably polyphenylene ether or an aromatic elastomer (styrene elastomer, etc.). In this case, not only the adhesiveness and low linear expansion of the molded article formed by this dispersion are further improved, but also the liquid physical properties (viscosity, thixotropic ratio, etc.) of this dispersion are also balanced, so its handling is easy get improved. Here, examples of the styrene elastomer include copolymers of styrene and conjugated diene or (meth)acrylate (styrene-butadiene rubber, styrene-based core-shell copolymer, styrene Ethylene-based block copolymers, etc.) are preferably styrene elastomers that have properties of both rubber and plastic, and are plasticized by heating to exhibit flexibility.

This dispersion liquid may further contain an inorganic filler. In this case, the electrical characteristics and low linear expansion of the molded article produced from this dispersion liquid tend to become excellent. In addition, this dispersion liquid may also contain inorganic fillers. Due to the above-mentioned mechanism of action, the dispersion stability is excellent, and it is easy to obtain a dense molded product. Therefore, it is easy to manufacture a molded article highly possessing the physical properties of each of the F polymer, the imide-based resin P, and the inorganic filler from the present dispersion containing the inorganic filler. Inorganic fillers are preferably nitride fillers or inorganic oxide fillers, more preferably boron nitride fillers, aluminum nitride fillers, beryllium oxide fillers (fillers of beryllium oxides), silicate fillers (silicon dioxide fillers, silicon dioxide fillers) Limestone filler, talc filler), or metal oxide (cerium oxide, aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, etc.) filler, and more preferably silica filler. The inorganic filler is preferably at least a part of its surface by a silane coupling agent (3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidyloxy propylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, etc.) for surface treatment.

The D50 of the inorganic filler is preferably less than 20 μm, more preferably less than 10 μm. D50 is preferably at least 0.01 μm, more preferably at least 0.1 μm. The shape of the inorganic filler can be any of granular, needle-like (fibrous) and plate-like. Specific shapes of inorganic fillers include: spherical, scaly, layered, leaf-shaped, almond-shaped, columnar, cockscomb-shaped, equiaxed, leaf-shaped, mica-shaped, block-shaped, flat-shaped, and wedge-shaped. Shaped, rosette, reticular, prismatic. An inorganic filler may be used individually by 1 type, and may use 2 or more types together. When this dispersion liquid further contains an inorganic filler, its amount is preferably 1 to 50 mass %, more preferably 5 to 40 mass %, based on the mass of this dispersion liquid as a whole.

Preferable specific examples of inorganic fillers include: silica fillers ("Admafine (registered trademark)" series manufactured by Admatechs, etc.), zinc oxide (Zinc oxide) surface-treated with esters such as propylene glycol dicaprate "FINEX (registered trademark)" series manufactured by Chemical Industry Co., Ltd., etc.), spherical fused silica ("SFP (registered trademark)" series manufactured by DENKA Corporation, etc.), coated with polyols and inorganic substances Titanium oxide ("Tipaque (registered trademark)" series manufactured by Ishihara Sangyo Co., Ltd., etc.), rutile-type titanium oxide surface-treated with alkylsilane ("JMT (registered trademark)" series manufactured by Imperial Chemical Industries, Ltd., etc.), Hollow silica fillers ("E-SPHERES" series manufactured by Taiheiyo Cement, "SiliNax" series manufactured by Nippon Steel Mining Co., Ltd., "Ecco sphere" series manufactured by Emerson & Cuming, etc.), talc fillers (NIPPON TALC "SG" series manufactured by the company, etc.), steatite filler ("BST" series manufactured by NIPPON TALC, etc.), boron nitride filler ("UHP" series manufactured by Showa Denko Corporation, "Denka Boron Nitride" manufactured by DENKA Corporation) series (“GP”, “HGP” grades), etc.).

In addition to the above-mentioned components, the dispersion liquid may further include thixotropy-imparting agents, viscosity regulators, defoamers, silane coupling agents, dehydrating agents, plasticizers, weather-resistant agents, and antioxidants within the range that does not impair the effects of the present invention. , heat stabilizer, lubricant, antistatic agent, whitening agent, colorant, conductive agent, release agent, surface treatment agent, flame retardant, various fillers and other ingredients.

The viscosity of the dispersion is preferably at least 10 mPa·s, more preferably at least 30 mPa·s, still more preferably at least 50 mPa·s. The viscosity of the dispersion is preferably not more than 3000 mPa·s, more preferably not more than 1000 mPa·s, still more preferably not more than 800 mPa·s. The viscosity of the dispersion is preferably 50-3000 mPa·s, more preferably 50-1000 mPa·s.

The thixotropy ratio of this dispersion is preferably 1.0 or more. The thixotropic ratio of this dispersion is preferably at most 3.0, more preferably at most 2.0. In this case, the dispersion liquid has excellent applicability and homogeneity, and it is easy to form a denser molded product (polymer layer, etc.). The pH of the dispersion is 5-10. In this dispersion, by adjusting the pH to this range, the functions of the imide resin P can be balanced. That is, if the pH of the dispersion is less than 5, the reactivity of the imide-based resin P becomes high, and on the other hand, its dispersing action decreases, resulting in a decrease in the dispersion stability of the dispersion. Also, if the pH of the dispersion exceeds 10, the dispersing effect of the imide resin P increases, and on the other hand, its reactivity decreases, resulting in a decrease in the physical properties of the molded product obtained from the dispersion. The pH value of the dispersion is preferably 7-9. In this case, the color phase and long-term storage stability of this dispersion liquid tend to become excellent.

In this dispersion, the dispersion layer ratio is preferably at least 60%, more preferably at least 70%, and still more preferably at least 80%. Here, the ratio of the dispersion layer is to put the dispersion (18 mL) into a spiral tube (inner volume: 30 mL) and let it stand at 25°C for 14 days, according to the total dispersion in the spiral tube after standing The height and the height of the precipitation layer (dispersion layer) are calculated by the following formula. In addition, when no precipitate layer was confirmed after standing still and the state did not change, it was assumed that the overall height of the dispersion liquid did not change, and the dispersion layer ratio was made 100%. Dispersion layer rate (%) = (height of precipitation layer) / (height of overall dispersion liquid) × 100

The present dispersion liquid is excellent in dispersion stability, especially long-term storage stability, due to the above-mentioned mechanism of action. When the dispersion is left to stand at 25° C. for 30 days, the variation range (absolute value) of the thixotropic ratio of the dispersion before and after standing is preferably 3 or less, more preferably less than 1.

This dispersion can be prepared by mixing F particles, imide resin P, and water as a dispersion medium. As a mixing method, for example: the method of adding F particles and imide resin P to water at one time or sequentially adding and mixing; F particles and water, imide resin P and water are mixed in advance, and then mixed The method of mixing the two mixtures obtained; etc. With regard to this dispersion liquid, it is advantageous and preferable to disperse the F particles more uniformly in the following way: after the F particles are pre-dispersed in water, the imide resin P is mixed as it is (directly) or mixed with Prepare this dispersion liquid in the order of adding and mixing in the state of water; or add and mix the F particles as they are (directly) or in the state of mixing in water after pre-mixing the imide resin P in water This dispersion was prepared sequentially. Furthermore, when the dispersion liquid further contains a surfactant, other resin materials, or inorganic fillers, it is preferable to add them at the same time when the F particles are previously dispersed in water, or to add them to water before dispersing the F particles.

As the mixing method when preparing the dispersion liquid, for example, a stirring device using a single shaft or multiple shafts equipped with blades (stirring blades) such as propeller blades, turbine blades, paddle blades, and shell blades, or Henschel mixing mixing machine, pressurized kneader, Banbury mixer or planetary mixer; using ball mill, attritor, basket mill, sand mill, sand grinder, DYNO-MILL (bead mill using glass beads or zirconia beads and other crushing media), Dispermat, SC mill, nail crusher or stirring mill and other media dispersing machines for mixing; using micro-spray homogenizer, Mixing by high-pressure homogenizers such as Nanomizer and Ultimaizer, ultrasonic homogenizers, dissolvers, dispersers, high-speed rotor dispersers, self-rotating and revolving mixers, film rotary high-speed mixers, and other dispersing machines that do not use media.

As a preferable aspect of the manufacturing method of this dispersion liquid, the aspect which kneads the composition containing F particle and water to obtain a kneaded product, and further mixes a kneaded product with water is mentioned. At this time, the imide-based resin P may be added to the composition, or may be added when the kneaded product is further mixed with water, but the former is preferable. That is, it is preferable to knead a composition containing F particles, imide-based resin P, and water to obtain a kneaded product, and further mix the kneaded product with water. The kneading can be carried out by the above-mentioned mixing method, preferably using a Henschel mixer, a pressure kneader, a Banbury mixer, a self-rotating mixer or a planetary mixer, and more preferably using a planetary mixer. The planetary mixer has a structure that has two shaft stirring blades that rotate and revolve mutually, and stirs and kneads the kneaded material in the stirring tank. Therefore, there is less dead space in the stirring tank that cannot be reached by the stirring blades, which can reduce the load on the blades and thus highly knead the composition. That is, the aggregation of the F particles can be suppressed, and the F particles can be wetted with water, and the F particles can be highly interacted with the imide resin P, and can be kneaded. Therefore, if the kneaded product is further mixed with water, then This dispersion liquid with excellent dispersion stability can be easily obtained. In addition, it is easy to adjust the component concentration of the present dispersion, and it is easy to obtain the present dispersion capable of forming a thick molded article (polymer layer, etc.) with excellent surface smoothness and uniformity.

The content of the F particles in the composition is preferably at least 20% by mass, more preferably at least 40% by mass, based on the total mass of the composition. The content of F particles is preferably at most 90% by mass. Also, the content of the imide-based resin P in the composition is preferably at least 0.1% by mass, more preferably at least 0.3% by mass, based on the overall mass of the composition. The content of the imide-based resin P is preferably at most 10% by mass. The total content of F particles and imide resin P in the composition is preferably at least 40% by mass, more preferably at least 60% by mass, based on the total mass of the composition. The above-mentioned total content is preferably at most 90% by mass.

Also, the ratio of the mass of the imide-based resin P in the composition to the mass of the F particles is preferably 0.001 or more, more preferably 0.005 or more, and still more preferably 0.01 or more. The above-mentioned ratio is preferably at most 0.1, more preferably at most 0.09, still more preferably at most 0.05. If the content of the F particles, the content of the imide resin P, or the above-mentioned ratio is in the lower range, then in the kneading of the composition, the F particles and the imide resin P can be highly interacted on the one hand, and on the other hand Mix it up. Therefore, when this kneaded product is further mixed with water, the present dispersion liquid having excellent dispersion stability in which the ratio of the mass of the imide resin P to the mass of the F particles is in the range of 0.001 to 0.1 can be easily obtained.

The kneaded product is a semi-solid or solid sticky substance, preferably kneaded slurry or kneaded powder. Furthermore, the kneaded slurry is a hard sticky substance in a fluid and viscous state, and the kneaded powder means a hard sticky substance in a lumpy and clay-like state. The viscosity of the kneaded slurry is preferably 800-100000 mPa·s, more preferably 1000-10000 mPa·s or more. The moisture content of the kneaded powder is preferably at most 50% by mass, more preferably at most 40% by mass. The moisture content of the kneaded powder is preferably at least 20% by mass, more preferably at least 25% by mass.

Also, in this aspect, when the present dispersion liquid further contains a surfactant, other resin materials, or inorganic fillers, these may be added to the composition, or may be added when the kneaded product is mixed with water. The present dispersion containing other resin materials or inorganic fillers can also be obtained by kneading a composition containing F particles, other resin materials or inorganic fillers, and water to obtain a kneaded product, and mixing the kneaded product, and a mixture comprising imide resin P and water are mixed. In this case, the dispersion stability and long-term storage stability of the present dispersion liquid are likely to be improved.

This dispersion liquid is also excellent in dispersion stability and long-term storage stability, and can be formed into a molded product that exhibits firm adhesion to the base material and is excellent in flexibility such as flex resistance, that is, crack resistance. If this dispersion is given to at least one surface of the substrate to form a liquid coating, the liquid coating is heated to remove the dispersion medium to form a dry coating, and then the coating is heated and dried, and the F polymer is fired, then the surface of the substrate can be obtained. A laminate (hereinafter, also referred to as "the present laminate") of a polymer layer (hereinafter also referred to as "F layer") comprising the F polymer and an imide-based resin P. In addition, if this dispersion is applied to both surfaces of the base material, heated, and the F polymer is fired, a laminate having F layers on both sides of the base material layer including the above base material can be obtained.

Examples of the base material include metal substrates (metal foils such as copper, nickel, aluminum, titanium, and alloys thereof), resin films (including tetrafluoroethylene-based polymers, polyimides, polyarylates, polyesters, etc.) One of heat-resistant resins such as polyarylene, polyamide, polyetheramide, polyphenylene sulfide, polyaryletherketone, polyamideimide, liquid crystalline polyester, liquid crystalline polyester amide, etc. The above heat-resistant resin films can be single-layer films or multi-layer films), prepregs (precursors of fiber-reinforced resin substrates), ceramic substrates (ceramic substrates such as silicon carbide, aluminum nitride, and silicon nitride) ,Glass base board. Among them, a resin film is preferable, and the resin constituting the resin film is more preferably a polyimide-based resin. This dispersion can be preferably used to form an F layer by applying to at least one surface of a resin film and drying. As a shape of a base material, a flat shape, a curved shape, and a concave-convex shape are mentioned, for example. In addition, the shape of the substrate may be any of foil shape, plate shape, film shape, and fiber shape.

As the method of applying the dispersion to the surface of the substrate, any method may be used as long as it forms a stable liquid film (wet film) containing the dispersion on the surface of the resin film (substrate). Examples include: Cloth method, droplet discharge method, dipping method, preferably coating method. If the coating method is used, a liquid film can be efficiently formed on the surface of the resin film with simple equipment. As the coating method, spray method, roll coating method, spin coating method, gravure coating method, micro gravure coating method, gravure offset method, knife coating method, contact coating method, bar coating method, etc. Cloth method, die coating method, spray Meile rod method, slot coating method, slot die coating method, dip coating method.

When drying the liquid coating, the liquid coating is heated at a temperature at which the dispersion medium (water) volatilizes to form a dry coating on the surface of the resin film. The heating temperature in this drying is preferably from 100 to 200°C. In addition, air may be blown in the step of removing the dispersion medium. During drying, the dispersion medium does not necessarily have to be completely volatilized, but only needs to be volatilized to such an extent that the shape of the layer is kept stable and a self-supporting film can be maintained.

When the F polymer is fired, it is preferable to heat and dry the film at a temperature higher than the melting temperature of the F polymer. The heating temperature is preferably below 380°C. As each heating method, a method using an oven, a method using a ventilated drying oven, and a method of irradiating hot rays such as infrared rays may, for example, be mentioned. Heating can be performed under either normal pressure or reduced pressure. Also, the heating atmosphere may be any of oxidizing gas atmosphere (oxygen, etc.), reducing gas atmosphere (hydrogen, etc.), inert gas atmosphere (helium, neon, argon, nitrogen, etc.). The heating time is preferably from 0.1 to 30 minutes, more preferably from 0.5 to 20 minutes. If heating is performed under the above-mentioned conditions, high productivity can be maintained and the F layer can be preferably formed.

The thickness of the F layer is preferably from 0.1 to 150 μm, more preferably at least 10 μm. When the substrate layer is a metal foil, the thickness of the F layer is preferably 10-30 μm. When the substrate layer is a resin film, the thickness of the F layer is preferably from 10 to 150 μm, more preferably from 15 to 50 μm. The peel strength between the F layer and the substrate layer is preferably at least 10 N/cm, more preferably at least 15 N/cm. The aforementioned peel strength is preferably 100 N/cm or less. This laminate can be easily formed without impairing the physical properties of the F polymer in the F layer by using the present dispersion.

The porosity of the F layer is preferably at most 30%, more preferably at most 20%. The porosity is preferably at least 0.1%, more preferably at least 1%. The F layer with a relatively low porosity can be easily formed from this dispersion. In particular, even when the porosity of the dry film is 1% or more, it is easy to form the F layer with a low porosity. Furthermore, the porosity is based on the SEM photo of the cross-section of the molded product observed with a scanning electron microscope (SEM), and the void portion of the F layer is determined by image processing, and the area occupied by the void portion is divided by F The ratio (%) obtained from the area of the layer. The area occupied by the void portion can be obtained by approximating the void portion to a circle.

This dispersion liquid can be applied to only one surface of the substrate, and can also be applied to both surfaces of the substrate. If it is the former, a base material layer including the above base material and a present laminate having an F layer on one surface of the base material layer can be obtained, and if it is the latter, a base material layer including the above base material, and the base material layer can be obtained. Both surfaces of the base material layer have the present laminate of the F layer. Since the latter laminate is less likely to warp, it has excellent workability during processing. Specific examples of this laminate include: a metal foil, and a metal foil laminate having an F layer on at least one surface of the metal foil; a polyimide film, and both surfaces of the polyimide film Multilayer film with F layer. Since these laminates have excellent electrical properties and many other physical properties, they are preferably used as printed substrate materials, etc., and can be used to manufacture flexible printed substrates or rigid printed substrates.

The present laminate having the F layer on both sides of the substrate layer is preferably obtained by applying the present dispersion to one surface of the substrate, heating to remove the liquid dispersion medium, and dispensing the present dispersion It is applied to the other surface of the substrate, heated to remove the liquid dispersion medium, and further heated to bake the F polymer to form each F layer.

In addition, the present laminate having F layers on both sides of the substrate layer can also be obtained by applying the present dispersion liquid to both surfaces of the substrate, heating to remove the liquid dispersion medium, and further The F polymer is fired by heating to form F layers on both surfaces at the same time. In this case, the present laminate having the F layer on both sides of the substrate layer is preferably obtained by immersing the substrate in the present dispersion and applying the present dispersion to both sides of the substrate. After the surface is formed, the substrate is heated by passing it through a firing furnace. Specifically, it is more preferably obtained by passing the substrate through a calcination furnace while pulling the substrate from the dispersion after immersing the substrate in the dispersion. The direction in which the substrate is pulled up and passed through the furnace is preferably vertically upward. In this case, it is easy to form a smooth F layer. After the substrate is pulled up vertically, the substrate can be further heated while being pulled vertically downward, or the substrate can be pulled vertically without heating. Moreover, the amount of this dispersion liquid to apply to a base material can be adjusted by passing the base material to which this dispersion liquid adhered between a pair of rolls. The present laminate can be preferably produced by using an apparatus having a dip coater and a firing furnace for the present laminate. As a baking furnace, a vertical baking furnace is mentioned, for example. Moreover, as this apparatus, the glass-cloth coating apparatus by Tabata Machine Industry Co., Ltd. is mentioned, for example.

Here, regarding the outermost surface of the substrate, in order to further improve its low linear expansion property or adhesiveness, the outermost surface of the substrate may be further subjected to surface treatment. The surface treatment method may, for example, be annealing treatment, corona treatment, plasma treatment, ozone treatment, excimer treatment, or silane coupling treatment. Regarding the conditions in the annealing treatment, it is preferable to set the temperature at 120 to 180° C., the pressure at 0.005 to 0.015 MPa, and the time at 30 to 120 minutes. Examples of the gas used in the plasma treatment include oxygen, nitrogen, rare gases (such as argon), hydrogen, ammonia, and vinyl acetate. These gases may be used alone or in combination of two or more. The ten-point average roughness of the surface of the substrate is preferably 0.01-0.05 μm.

The laminate in which the substrate layer is a resin film (preferably a polyimide film) can be used as a release film or a carrier film. Since the layer F of this laminate has excellent adhesion to the substrate layer, interlayer delamination is not easy to occur, so it can be used repeatedly as a carrier film. Also, since the F layer is excellent in heat resistance, even if it is used repeatedly, the release property is not likely to deteriorate.

Specifically, if a dispersion liquid or varnish containing a resin or an inorganic filler is applied to the surface of the layer F of the laminate, dried to form a coating film, and then the laminate is peeled off from the coating film, an independent product can be obtained. The coating film. For example, if after forming the above-mentioned coating film on the surface of the F layer of this laminated body, the coated film side of this laminated body having the coating film is bonded to other substrates, and the laminated body is peeled off, then other substrates and other substrates can be obtained. Laminated body of coating film. When forming a coating film on the surface of the layer F of this laminate, for example, heating may be performed at a temperature below the melting point of the F polymer during drying. Since this laminate has excellent heat resistance, it is not easily deformed even if heat treatment is repeated.

Specifically, this laminate can be used as a supporting film for forming ceramic green sheets, a supporting film for forming secondary batteries, a supporting film for forming solid polymer electrolyte membranes, and a supporting film for forming catalysts for solid polymer electrolyte membranes. membrane. When using this laminate as a carrier film, from the viewpoint of obtaining the above-mentioned coating film with a uniform thickness, the ratio of the thickness of the end portion of this laminate to the thickness of the central portion is preferably 1.1 or less, more preferably 1.07 Below, more preferably below 1.04. The thickness ratio is 1 or more.

It is also possible to laminate other substrates on the outermost surface of this laminate. Examples of other substrates include a metal substrate, a heat-resistant resin film, a prepreg of a precursor of a fiber-reinforced resin plate, a laminate having a heat-resistant resin film layer, and a laminate having a prepreg layer. Furthermore, the prepreg system is a sheet-like substrate obtained by impregnating a thermosetting resin or a thermoplastic resin in a base material (tow, woven fabric, etc.) of reinforcing fibers (glass fiber, carbon fiber, etc.). As a metal substrate, the said metal substrate is mentioned. The heat-resistant resin film is a film containing one or more heat-resistant resins, and the heat-resistant resin may, for example, be the above-mentioned resins.

As a lamination method, a method of hot-pressing this laminate and another substrate may be mentioned. As for the hot pressing conditions when the other substrate is a prepreg, it is preferable to set the temperature at 120 to 400°C, set the atmospheric pressure to a vacuum of 20 kPa or less, and set the pressing pressure to 0.2 to 10 MPa. Since this laminate has an F layer with excellent electrical properties, it is preferably used as a printed substrate material. Specifically, it can be used to manufacture a printed substrate in the form of a flexible metal foil laminate or a rigid metal foil laminate. In particular, it can be used as a printed substrate. The flexible printed substrate is preferably manufactured in the form of a flexible metal foil laminate.

In the case of the metal foil of the original laminate (metal foil with F layer) where the base layer is metal foil, and the metal foil laminate where the base layer is a resin film and has an F layer and then laminated with metal foil (Metal foil with resin film and F layer) is etched to form a transmission circuit, and a printed circuit board can be obtained. Specifically, the printed substrate can be manufactured by the following method, that is, the method of etching the metal foil to process it into a specific transmission circuit, or by the electroplating method (semi-additive method (SAP method), MSAP (Modified Semi -Additive, modified semi-additive method, etc.) and the method of processing metal foil into a specific transmission circuit. A printed circuit board manufactured from metal foil with F layer and metal foil with resin film and F layer has a transmission circuit and F layer formed of metal foil in this order. Specific examples of the composition of the printed circuit board include: transmission circuit/F layer/prepreg layer, transmission circuit/F layer/prepreg layer/F layer/transmission circuit, transmission circuit/F layer/polyimide film layer, transmission circuit/F layer/polyimide film layer/F layer/transmission circuit. In the manufacture of the printed circuit board, an interlayer insulating film may be formed on the transmission circuit, a solder resist may be laminated on the transmission circuit, and a coverlay film may be laminated on the transmission circuit. These interlayer insulating films, solder resists, and coverlay films can also be formed from this dispersion.

Since the base layer is a metal substrate, the laminate has excellent insulation and heat dissipation properties, so it can also be used as a heat dissipation substrate, especially a substrate for mounting power semiconductors. In this case, the shape of the base material is preferably a plate shape, and the base material is preferably a copper plate or an aluminum plate. The thickness of the substrate is preferably 0.1-3 mm. In the production of this laminate in this case, a slit coating method is preferable as a method of coating this dispersion liquid on a base material. The F polymer in this case is preferably an F polymer having a melting temperature of 200° C. to 320° C., more preferably a polymer having an oxygen-containing polar group including the above-mentioned TFE unit and PAVE unit.

In this case, the imide-based resin P is preferably an aromatic polyimide, an aromatic polyimide precursor, an aromatic polyamide imide, or an aromatic polyamide imide precursor. . In this case, it is preferable that the F layer further contains an inorganic filler. As the inorganic filler, boron nitride filler, aluminum nitride filler or alumina filler is preferred. That is, in the laminated body used as a heat dissipation substrate, the F polymer is a polymer having an oxygen-containing polar group including the above-mentioned TFE unit and a PAVE unit, preferably the imide resin P is an aromatic polyimide Amine, aromatic polyamide imide precursor, aromatic polyamide imide or aromatic polyamide imide precursor, and preferably include boron nitride filler, aluminum nitride filler in the F layer or alumina filler. In this case, it is particularly easy to improve the insulation and heat dissipation properties of the heat dissipation substrate as the laminate.

When using this laminated body as a heat dissipation substrate, it is preferable to use this laminated body processed into the laminated body which has a metal layer, an F layer, and a metal layer in this order. This laminate can be obtained by thermocompression-bonding the metal substrate on the surface of the F layer of this laminate, or by laminating two of this laminate in such a way that the F layer faces each other and performing thermocompression bonding on the F layer. Better for the latter. As a method of thermocompression bonding, thermocompression is preferable. The thicknesses of the two metal layers in the laminate may be the same or different. In addition, the metals in the two metal layers may be the same or different. For example, if the F layer of the laminate having the F layer on the surface of an aluminum plate with a thickness of 1 mm and the F layer of the laminate having an F layer on the surface of a copper plate with a thickness of 0.5 mm are thermocompressed and bonded by thermocompression, then A laminate having an aluminum plate, an F layer, and a copper plate in this order and two metal layers having different thicknesses was obtained.

This laminate, or a laminate of this laminate and other substrates, can be used as antenna parts, printed circuit boards, aircraft parts, automotive parts, sports equipment, food industry supplies, paints, heat dissipation parts, cosmetics, etc. Specifically, It can be used as wire covering material (wires for aircraft, etc.), electrical insulating tape, insulating tape for oil development, printed circuit board material, separation membrane (microfiltration membrane, ultrafiltration membrane, reverse osmosis membrane, ion exchange membrane, dialysis membrane) , gas separation membranes, etc.), electrode binders (for lithium secondary batteries, fuel cells, etc.), replica rolls, furniture, automobile dashboards, home appliances, etc. , gears, cams, belt conveyors, conveyor belts for food transportation, etc.), tools (shovels, files, awls, saws, etc.), boilers, hoppers, pipes, ovens, baking molds, chutes, molds, toilets, container coatings Materials, heat dissipation substrates for power devices, transistors, thyristors, rectifiers, transformers, power MOS FETs (Metal-Oxide -Semiconductor Field, metal oxide semiconductor field effect transistors), CPU (Central Processing Unit, central processing unit) , heat sinks, metal heat sinks, blades of windmills or wind power generation equipment or aircraft, housings of computers or displays, components of electronic devices, interior and exterior components of automobiles, processing machines or vacuum ovens for heat treatment under low oxygen, Sealing components of plasma processing devices, heat dissipation parts and electromagnetic wave shielding components in processing units such as sputtering or various dry etching devices.

As mentioned above, this dispersion liquid, the manufacturing method of this dispersion liquid, and this laminated body were demonstrated, but this invention is not limited to the structure of the said embodiment. For example, this dispersion liquid and this laminated body may add another arbitrary structure to the structure of the said embodiment, and may replace it with the arbitrary structure which performs the same function. Moreover, the manufacturing method of this dispersion liquid may also have other arbitrary steps by adding to the structure of the said embodiment, and may replace with the arbitrary steps which produce the same effect. [Example]

Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. 1. Details of each component [F particle] F particle 1: Consists of 97.9 mol% of TFE units, 0.1 mol% of NAH units, and 2.0 mol% of PPVE units, and every 1×10 ⁶ main chain carbons Particles (D50: 2.1 μm) formed by a polymer with 1000 carbonyl-containing groups (melting temperature: 300°C) F Particle 2: Containing 97.5 mol% of TFE units and 2.5 mol% of PPVE units Particles (D50: 1.8 μm) formed by polymers (melting temperature: 305°C) having 25 carbonyl-containing groups per 1×10 ⁶ carbons in the main chain D50: 0.2 μm) [F dispersion liquid] F dispersion liquid 1: Aqueous dispersion liquid containing 60% by mass of F particles 3 ("AD-911E" manufactured by AGC Corporation) [Varnish of imide resin] Varnish 1: Water varnish containing aromatic polyamideimide (PAI1) precursor (acid value: 50 mgKOH/g) [Surfactant] Surfactant 1: Main chain has dimethylsiloxane unit and main chain Polyoxyalkylene modified polydimethylsiloxane with oxyethylene at the end or side chain (weight average molecular weight: 1600, dispersion: 1.5, HLB value: 13, static surface tension: 25 mN/m, Dynamic surface tension of 0.1% by mass aqueous solution: 30 mN/m) [pH adjuster] Amine 1: Triethanolamine acid 1: Formic acid [Nonionic polymer] Polysaccharide 1: Hydroxyethyl cellulose (Sumitomo Seika Co., Ltd. Manufactured "HEC CF-Y") [Water-soluble polymer with non-ionic hydroxyl groups] [Resin film (substrate)] Polyimide film 1: Aromatic polyimide film (PI "FG-100" manufactured by Advanced Materials)

2. Manufacture and evaluation of dispersion [Example 1-1] Put F particle 1, varnish 1, surfactant 1 and water into the crucible, and put zirconia balls into it. Thereafter, the crucible was rotated at 150 rpm for 1 hour, and amine 1 was added to obtain a mixture containing F particle 1 (60 parts by mass), PAI1 (0.6 parts by mass), surfactant 1 (3 parts by mass) and water (46.4 parts by mass). The dispersion liquid 1. The obtained dispersion 1 had a viscosity of 1000 mPa·s and a pH of 8.0. Even when the dispersion liquid 1 was stored at 25° C. for a long period of time, no aggregates were observed, and the dispersibility was excellent.

[Example 1-2] F particles 1, varnish 1, surfactant 1, and water were put into a crucible and mixed to prepare a composition. The composition was kneaded in a planetary mixer and then taken out to obtain F particles 1 (60 parts by mass), PAI1 (0.6 parts by mass), surfactant 1 (3 parts by mass) and water (20 parts by mass). Mixing powder 1. Water was added to the kneaded powder 1 several times, and stirred while defoaming at 2000 rpm by a self-rotating mixer. Furthermore, water was added several times while stirring, and amine 1 was added to obtain a mixture containing F particle 1 (60 parts by mass), PAI1 (0.6 parts by mass), surfactant 1 (3 parts by mass) and water (46.4 parts by mass). ) of the dispersion 2. The obtained dispersion 2 had a viscosity of 800 mPa·s and a pH of 8.0.

[Example 1-3]～[Example 1-6] Dispersions 3 to 6 were obtained in the same manner as in Example 1-2 except that the types or amounts of F particles, varnish, pH adjuster, and water were changed as shown in Table 1.

[Example 1-7] F particles 1, varnish 1, surfactant 1, and water were put into a crucible and mixed to prepare a composition. The composition was kneaded in a planetary mixer and then taken out to obtain F particle 1 (50 parts by mass), PAI (0.6 parts by mass), surfactant 1 (3 parts by mass) and water (20 parts by mass). Mixing powder7. Add F dispersion liquid 1 to the kneading powder 7, and then add water several times, and stir while defoaming at 2000 rpm with a self-rotating mixer. Furthermore, water was added several times while stirring, and amine 1 was added to obtain a mixture containing F particle 1 (50 parts by mass), F particle 3 (10 parts by mass), PAI1 (0.6 parts by mass), surfactant 1 (3 parts by mass). parts by mass) and water (46.4 parts by mass) of the dispersion 7. The obtained dispersion 7 had a viscosity of 700 mPa·s and a pH of 8.0.

[Example 1-8] F particles 1, varnish 1, surfactant 1, polysaccharide 1, and water were put into a crucible and mixed to prepare a composition. The composition was taken out after kneading in a planetary mixer to obtain a mixture containing F particle 1 (50 parts by mass), PAI (0.6 parts by mass), surfactant 1 (3 parts by mass), polysaccharide 1 (0.3 parts by mass) ) and water (20 parts by mass) of mixed powder 8. Add F dispersion 1 to the kneaded powder 8, and then add water several times, and stir while defoaming at 2000 rpm with a self-rotating and revolving mixer. Furthermore, water was added several times while stirring, and amine 1 was added to obtain a mixture containing F particle 1 (50 parts by mass), F particle 3 (10 parts by mass), PAI1 (0.6 parts by mass), surfactant 1 (3 parts by mass). parts by mass), polysaccharide 1 (0.3 parts by mass) and water (46.1 parts by mass) dispersion 8. The obtained dispersion 8 had a viscosity of 3000 mPa·s and a pH of 8.0.

[Table 1] Dispersion No. 1 2 3 4 5 6 7 8 F particle F particle 1 (60) F particle 1 (60) F particle 1 (50) F particle 2 (60) F particle 2 (60) F particle 2 (60) F particle 1 (50) F particle 3 (10) F particle 1 (50) F particle 3 (10) imide resin PAI1(0.6) PAI1(0.6) PAI1(15) PAI1(0.6) PAI1(0.6) PAI1(0.6) PAI1(0.6) PAI1(0.6) Surfactant Surfactant 1 (3) Surfactant 1 (3) Surfactant 1 (3) Surfactant 1 (3) Surfactant 1 (3) Surfactant 1 (3) Surfactant 1 (3) Surfactants 1 (3) dispersion medium water (46.4) water (46.4) water (46.4) water (46.4) water (46.4) water (46.4) water (46.4) water (46.1) pH adjuster Amine 1 Amine 1 Amine 1 Amine 1 acid 1 Amine 1 Amine 1 Amine 1 nonionic polymer - - - - - - - Polysaccharides 1 (0.3) Viscosity [mPa・s] 1000 800 1100 1300 1300 1400 700 3000 pH value 8.0 8.0 8.0 8.0 4.8 13.0 8.0 8.0 ※The numbers in parentheses in each ingredient column indicate the content (parts by mass).

3. Manufacture and evaluation of laminates [Example 2-1] The dispersion liquid 1 obtained according to Example 1-1 was coated on one side of the polyimide film 1 by the small-diameter reverse gravure method by the roll-to-roll process, and it took 3 minutes to pass it through the ventilated drying oven (furnace temperature 150°C), water was removed to form a dry film. Also, in the same manner, the dispersion liquid 1 was applied to the other surface of the polyimide film 1 and dried to form a dry film. Next, it takes 5 minutes to make the polyimide film 1 with a dry film formed on both sides pass through a far-infrared ray furnace (the temperature of the furnace near the entrance and exit of the furnace is 300°C, and the temperature of the furnace near the center is 360°C), so that the F particles 1 Melt roasting. In this way, a polymer layer comprising the melt-fired product of F particles 1 and PAI1 is formed on both sides of the polyimide film 1, and the polymer layer and the polyimide film layer are directly formed in sequence by a roll-to-roll process. and a laminate of polymer layers (multilayer film 1). The thickness of the polymer layer in the multilayer film 1 is 25 μm.

[Example 2-2]～[Example 2-8] Multilayer films 2 to 7 were obtained in the same manner as in Example 2-1, except that dispersion liquids 2 to 8 were used instead of dispersion liquid 1. The porosity of the polymer layers of each multilayer film gradually decreases in the order of multilayer film 2, multilayer film 1, multilayer films 3 and 4, and multilayer films 5 and 6, and the polymer layer of multilayer film 2 is the densest.

4. Evaluation 4-1. Evaluation of dispersion layer rate of dispersion liquid Each dispersion (18 mL) was put into a spiral tube (inner volume: 30 mL), and left to stand at 25° C. for 14 days. Based on the overall height of the dispersion in the spiral tube after standing and the height of the precipitation layer (dispersion layer), the dispersion layer ratio was calculated by the following formula, and the dispersion stability was evaluated according to the following criteria. [evaluation criteria] 〇: The dispersed layer ratio is 80% or more. Δ: The dispersed layer ratio is 60% or more and less than 80%. ×: The dispersion layer ratio is less than 60%.

4-2. Variation range of the thixotropic ratio of the dispersion Each dispersion liquid was stored in a container at 25° C. for 30 days, and the variation range of the thixotropic ratio before and after storage was measured, and the thixotropic stability was evaluated according to the following criteria. [evaluation criteria] 〇: The variation range (absolute value) of the thixotropic ratio is less than 1 △: The variation range (absolute value) of the thixotropic ratio is 1 to 3 ×: The variation range (absolute value) of the thixotropic ratio exceeds 3

4-3. Evaluation of surface smoothness of multilayer film The surface of the polymer layer of each multilayer film was visually confirmed, and the surface smoothness was evaluated according to the following criteria. [evaluation criteria] 〇: There are no pinholes on the surface of the polymer layer. X: There are pinholes on the surface of the polymer layer.

4-4. Evaluation of interlayer adhesion of multilayer film Cut out a rectangular (length 100 mm, width 10 mm) test piece from each multilayer film, fix it at a position 50 mm away from one end of the test piece in the length direction, and test it from one end of the length direction at a tensile speed of 50 mm/min The sheet was peeled off the polymer layer and the polyimide film layer at 90°. The maximum load applied at this time was defined as the peel strength, and the interlayer adhesiveness was evaluated according to the following criteria. [evaluation criteria] ○: The peel strength is 15 N/cm or more. Δ: The peel strength is 10 N/cm or more and less than 15 N/cm. ×: Peel strength is less than 10 N/cm. The respective evaluation results are collectively shown in Table 2 below.

[Table 2] Dispersion or Multilayer Film No. 1 2 3 4 5 6 7 8 dispersion stability 〇 〇 △ △ x x 〇 〇 Variation range of thixotropic ratio △ 〇 △ x x x 〇 〇 Surface smoothness 〇 〇 〇 △ x x 〇 〇 Adhesiveness between layers △ 〇 △ △ x △ 〇 〇

Furthermore, the dielectric loss factor of each multilayer film was measured by the SPDR (separated column dielectric resonance) method (measurement frequency: 10 GHz). As a result, the dielectric loss factor of multilayer films 7 and 8 was the lowest, and the electrical characteristics of the two multilayer films more excellent. In addition, the thickness of the polymer layer having surface smoothness and interlayer adhesion that can be formed by a single manufacturing process of the laminate is the largest when the dispersion liquid 8 is used. [Industrial availability]

The aqueous dispersion of the present invention has excellent dispersion stability and can be easily processed into films, fiber-reinforced films, prepregs, and metal laminates (metal foil with resin). The obtained processed articles can be used as materials for antenna parts, printed substrates, aircraft parts, automobile parts, sports equipment, food industry supplies, sliding bearings, etc. In addition, since the laminate of the present invention has excellent heat resistance and release properties, it can also be used as a carrier film for forming ceramic green sheets, a carrier film for forming secondary battery electrode films, and a carrier film for forming solid polymer electrolyte membranes. Carrier film, carrier film for catalyst formation of solid polymer electrolyte membrane.

Claims (15)

An aqueous dispersion liquid, which comprises tetrafluoroethylene polymer particles, aromatic imide resin with an acid value of 20-100 mg/KOH, and water, and has a pH value of 5-10. The aqueous dispersion according to claim 1, wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having an oxygen-containing polar group including a perfluoro(alkyl vinyl ether)-based unit. The aqueous dispersion according to claim 1 or 2, wherein the tetrafluoroethylene-based polymer particles include non-heat-fusible tetrafluoroethylene-based polymer particles and heat-fusible tetrafluoroethylene-based polymer particles. The aqueous dispersion according to any one of claims 1 to 3, wherein the above-mentioned aromatic imide resin is a precursor of water-soluble aromatic polyimide or a precursor of water-soluble aromatic polyimide . The aqueous dispersion according to any one of claims 1 to 4, further comprising an inorganic filler. The aqueous dispersion according to any one of claims 1 to 5, further comprising a nonionic surfactant. The aqueous dispersion according to any one of Claims 1 to 6, which further comprises at least one nonionic compound selected from the group consisting of polyvinyl alcohol-based polymers, polyvinylpyrrolidone-based polymers, and polysaccharides. polymer. The aqueous dispersion according to any one of claims 1 to 7, which contains amine or ammonia. The aqueous dispersion according to any one of claims 1 to 8, wherein the ratio of the mass of the aromatic imide resin to the mass of the tetrafluoroethylene polymer particles is in the range of 0.001 to 0.1. The aqueous dispersion according to any one of claims 1 to 9, wherein the total content of the particles and the aromatic imide-based resin in the aqueous dispersion is 20% by mass or more relative to the total mass of the aqueous dispersion . The aqueous dispersion according to any one of Claims 1 to 10, which has a viscosity of 50 to 3000 mPa·s. The aqueous dispersion according to any one of claims 1 to 11, which is used to form a polymer layer containing a tetrafluoroethylene polymer by applying to at least one surface of a resin film and heating. The aqueous dispersion according to any one of claims 1 to 12, wherein the resin constituting the resin film is a polyimide resin. A method for producing an aqueous dispersion, which is the method for producing an aqueous dispersion according to any one of Claims 1 to 13, comprising the above-mentioned tetrafluoroethylene-based polymer particles, the above-mentioned aromatic imide-based resin, and water The composition is kneaded to obtain a kneaded product, and the kneaded product is mixed with water to obtain the above-mentioned aqueous dispersion. A laminate, which is to apply the aqueous dispersion according to any one of claims 1 to 13 to both surfaces of the resin film, and heat it to form the above polymer layer comprising a tetrafluoroethylene polymer. The base material layer of the resin film has the above-mentioned polymer layer on both sides.