WO2022145333A1

WO2022145333A1 - Aqueous dispersion and method for producing same

Info

Publication number: WO2022145333A1
Application number: PCT/JP2021/047823
Authority: WO
Inventors: 創太結城; 渉笠井; 蔵藤岡
Original assignee: Ａｇｃ株式会社
Priority date: 2020-12-28
Filing date: 2021-12-23
Publication date: 2022-07-07
Also published as: TW202235524A; JPWO2022145333A1; KR20230126703A

Abstract

[Problem] 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. [Solution] 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 and its manufacturing method

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

Tetrafluoroethylene-based polymers such as polytetrafluoroethylene (PTFE) have excellent physical properties such as electrical properties, water and oil repellency, chemical resistance, and heat resistance, and are used in various industrial applications (Patent Documents). 1). As a coating agent used to impart the physical properties to the surface of the base material, a dispersion liquid containing particles of a tetrafluoroethylene-based polymer is known.
In particular, in recent years, a dispersion containing tetrafluoroethylene polymer particles has attracted attention as a material having excellent electrical properties such as low dielectric constant and low dielectric loss tangent, which forms a dielectric layer of a printed circuit board corresponding to frequencies in the high frequency band. Has been done.

From the viewpoint of handleability, it is preferable to use the dispersion liquid as 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 the resin film. Patent Document 3 discloses a composition containing an aqueous polyimide precursor, a fluororesin, and water, and these are uniformly mixed.

Japanese Unexamined Patent Publication No. 2019-218484 Japanese Unexamined Patent Publication No. 09-157418 Japanese Unexamined Patent Publication No. 2016-20488

However, the aqueous dispersion of the tetrafluoroethylene polymer is generally inferior in the dispersed state as compared with the non-aqueous dispersion. Therefore, in coating and firing on the base material, the packing of the particles of the tetrafluoroethylene-based polymer becomes loose, and a problem tends to occur in the denseness of the polymer layer to be formed. Specifically, when the polymer layer is formed on a substrate such as a resin film by a continuous production process such as roll-to-roll, cracks and pinholes are likely to occur in the polymer layer. According to the studies by the present inventors, it has been found that these tendencies become remarkable when the aqueous dispersion of the prior art document is used.

As a result of diligent studies, the present inventors have found that a dispersion liquid containing tetrafluoroethylene polymer particles, a specific aromatic imide resin, and water and having a pH in a specific range is excellent in dispersion stability. I found that. In addition, the molded product obtained from such a dispersion is dense, has excellent low dielectric loss tangent and low coefficient of linear expansion, flexibility such as bending resistance, UV absorption, and adhesion to plastic films such as polyimide film. It was found that the adhesion was improved.
An object of the present invention is to provide an aqueous dispersion having excellent dispersion stability, flexibility such as bending resistance, UV absorption, and adhesiveness / adhesion to a resin film such as a polyimide film. It is an offer.

The present invention has the following aspects.
<1> An aqueous dispersion containing particles of a tetrafluoroethylene polymer, an aromatic imide resin having an acid value of 20 to 100 mg / KOH, and water, and having a pH of 5 to 10.
<2> The aqueous dispersion of <1>, wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having an oxygen-containing polar group containing a unit based on perfluoro (alkyl vinyl ether).
<3> The particles of the tetrafluoroethylene-based polymer include particles of the non-heat-meltable tetrafluoroethylene-based polymer and particles of the heat-meltable tetrafluoroethylene-based polymer, according to <1> or <2>. Aqueous dispersion.
<4> The aqueous dispersion according to any one of <1> to <3>, wherein the aromatic imide resin is a precursor of a water-soluble aromatic polyamide-imide or a precursor of a water-soluble aromatic polyimide.
<5> The aqueous dispersion according to any one of <1> to <4>, further containing an inorganic filler.
<6> The aqueous dispersion according to any one of <1> to <5>, further containing a nonionic surfactant.
<7> The aqueous dispersion according to any one of <1> to <6>, further containing at least one nonionic polymer selected from the group consisting of a polyvinyl alcohol-based polymer, a polyvinylpyrrolidone-based polymer, and a polysaccharide.
<8> The aqueous dispersion according to any one of <1> to <7>, which contains amine or ammonia.
<9> Any of <1> to <8>, wherein the ratio of the mass of the aromatic imide resin to the mass of the particles of the tetrafluoroethylene polymer is in the range of 0.001 to 0.1. Aqueous dispersion.
<10> Any of <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 with respect to the total mass of the aqueous dispersion. Aqueous dispersion.
<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 polymer by applying it to at least one surface of a resin film and heating it.
<13> The aqueous dispersion according to any one of <1> to <12>, wherein the resin constituting the resin film is a polyimide resin.
<14> A composition containing the tetrafluoroethylene polymer particles, the aromatic imide resin, and water is kneaded to obtain a kneaded product, and the kneaded product and water are mixed to obtain the aqueous dispersion. The method for producing an aqueous dispersion according to any one of <1> to <13>.
<15> With the resin film, any of the aqueous dispersions of <1> to <13> is applied to both surfaces of the resin film and heated to form the polymer layer containing the tetrafluoroethylene polymer. A laminate having the polymer layer on both sides of the constituent base material layer.

According to the present invention, it is possible to provide an aqueous dispersion of a tetrafluoroethylene polymer having excellent dispersion stability and a method for producing such an aqueous dispersion. The aqueous dispersion of the present invention has excellent physical properties such as low dielectric loss tangent and low transmission loss, flexibility such as bending resistance, UV absorption, and adhesion to resin films such as polyimide film. A molded body having excellent adhesion can be formed. Therefore, the aqueous dispersion of the present invention is useful, for example, as a constituent material for a printed circuit board.

The following terms have the following meanings.
The "average particle diameter (D50)" is a volume-based cumulative 50% diameter of an object (particle and filler) determined by a laser diffraction / scattering method. That is, the particle size distribution is measured by the laser diffraction / scattering method, the cumulative curve is obtained with the total volume of the group of objects (particles and fillers) as 100%, and the particles at the point where the cumulative volume is 50% on the cumulative curve. The diameter.
The D50 of the object (particles and filler) is a laser that disperses the object (particles and filler) in water and uses a laser diffraction / scattering type particle size distribution measuring device (LA-920 measuring instrument manufactured by HORIBA, Ltd.). It is obtained by analysis by the diffraction / scattering method.
The "melting temperature" is the temperature corresponding to the maximum value of the melting peak of the polymer measured by the differential scanning calorimetry (DSC) method.
The "viscosity" is determined by measuring an object (dispersion liquid and kneaded product) at 25 ° C. and a rotation speed of 30 rpm using a B-type viscometer. The measurement is repeated 3 times, and the average value of the measured values for 3 times is used.
The "thixotropic ratio" is the viscosity η ₁ of the object (dispersion liquid and kneaded product) measured under the condition of 30 rpm divided by the viscosity η ₂ measured under the condition of 60 rpm. It is a calculated value. The measurement of each viscosity is repeated 3 times, and the average value of the measured values for 3 times is used.
The "HLB value of polyoxyalkylene-modified polydimethylsiloxane" is a value calculated by the Griffin formula, and is obtained by multiplying the molecular weight of the polyoxyalkylene portion in the molecule by the molecular weight of organopolysiloxane by 20. Be done.
"Static surface tension" is determined by the Wilhelmy method using an automatic surface tension meter CBVP-Z type (manufactured by Kyowa Surface Science Co., Ltd.) and a 0.1% by mass aqueous solution of polyoxyalkylene-modified polydimethylsiloxane. ..
"Dynamic surface tension" is the dynamic surface tension of a 0.1% by mass aqueous solution of polyoxyalkylene-modified polydimethylsiloxane at 25 ° C. at a bubble generation cycle of 6 Hz by the maximum foam pressure method, and is polyoxyalkylene-modified. The dynamic surface tension of an aqueous solution containing polydimethylsiloxane at a ratio of 0.1% by mass was immersed in the aqueous solution by immersing the sensor of the dynamic surface tension meter Theta t60 manufactured by Eiko Seiki Co., Ltd. in an environment at a temperature of 25 ° C. It is a value measured by the maximum foam pressure method. The measurement is carried out by setting the generation cycle of bubbles in the aqueous solution to 6 Hz.
By "unit" in a polymer is meant an atomic group based on the monomer formed by polymerization of the monomer. The unit may be a unit directly formed by a polymerization reaction, or may be a unit in which a part of the unit is converted into another structure by processing a polymer. Hereinafter, the unit based on the monomer a is also simply referred to as “monomer a unit”.

The aqueous dispersion of the present invention (hereinafter, also referred to as “the present dispersion”) is a particle of a tetrafluoroethylene-based polymer (hereinafter, also referred to as “F polymer”) (hereinafter, also referred to as “F particle”). It contains an aromatic imide-based resin having an acid value of 20 to 100 mg / KOH (hereinafter, also referred to as “imide-based resin P”) and water, and has a pH of 5 to 10.

This dispersion has excellent dispersion stability. In addition, the molded product (baked product) formed from this dispersion has excellent physical properties based on the tetrafluoroethylene polymer such as electrical characteristics, excellent surface smoothness, flexibility such as bending resistance, and UV absorption. It also has excellent properties and adhesiveness and adhesion to resin films such as polyimide films.
The reason why the dispersion stability of this dispersion is improved is not always clear, but it is estimated as follows, for example.
Since the imide-based resin P in the present invention has a specific acid value, it easily interacts with F particles and water, and not only acts as a dispersant for F particles in the dispersion liquid, but also acts as a viscosity modifier for the dispersion liquid. However, it is considered that the dispersion stability of this dispersion is improved. Further, the fact that the pH of the present dispersion is in a specific range not only enhances such an action, but also enhances the reactivity of the imide-based resin P when the present dispersion is 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 base material is enhanced, and the flexibility, adhesiveness and adhesion (binder ability) of the obtained molded product are improved. As a result, it is considered that this dispersion has excellent dispersion stability, and a molded product having excellent electrical characteristics, bending resistance, UV absorption, etc. could be formed from this dispersion by a continuous production process such as roll-to-roll. Be done.

The F polymer in this dispersion is a polymer containing a unit (TFE unit) based on tetrafluoroethylene (TFE). As the F polymer, one kind may be used, or two or more kinds may be used. The F polymer may be hot meltable or non-hot meltable, but at least one of the F polymers is preferably hot meltable. In such a case, the molded product formed from the present dispersion tends to have excellent flexibility and adhesiveness / adhesion to a resin film such as a polyimide film. The thermal meltability is a melt-fluid polymer having a melt flow rate of 0.1 to 1000 g / 10 minutes at a temperature 20 ° C. or higher higher than the melt temperature of the polymer under a load of 49 N. means.
When the F polymer is thermally meltable, the melting temperature is preferably 200 to 320 ° C, more preferably 260 to 320 ° C. In such a case, the molded product formed from the present dispersion tends to have excellent heat resistance.

The fluorine atom content in the F polymer is preferably 70% by mass or more, and more preferably 70 to 76% by mass. Due to the above-mentioned mechanism of action, the present dispersion is particularly likely to improve the dispersibility of F polymer particles having a high fluorine atom content in water.
The glass transition point of the F polymer is preferably 75 to 125 ° C, more preferably 80 to 100 ° C.

F-polymers include polytetrafluoroethylene (PTFE), polymers containing TFE units and units based on ethylene (ETFE), polymers containing TFE units and units based on perfluoro (alkyl vinyl ether) (PAVE) (PAVE units) (PFA). ), Polymers (FEPs) containing TFE units and units based on hexafluoropropene (HFP). Each of ETFE, PFA and FEP may further contain other units. As the 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.

At least one of the F polymers preferably has an oxygen-containing polar group. In this case, since the affinity between the F polymer and the imide-based resin P and water is improved, this dispersion tends to be excellent in dispersion stability. Further, in this case, it is considered that the F polymer reacts with the imide resin P to form a crosslink when the present dispersion is fired, and as a result, the calcined product (polymer layer or the like) obtained from the present dispersion has electrical characteristics. It is considered that the surface smoothness and physical properties such as adhesiveness and adhesion to a resin film such as a polyimide film are further excellent.
The oxygen-containing polar group may be contained in a unit in the F polymer, or may be contained in the terminal group of the main chain of the F polymer. In the latter aspect, an F polymer having an oxygen-containing polar group as a terminal group derived from a polymerization initiator, a chain transfer agent, or the like, or an F having an oxygen-containing polar group obtained by subjecting the F polymer to plasma treatment or ionization line treatment. Examples include polymers. As the oxygen-containing polar group, a hydroxyl group-containing group, a carbonyl group-containing group and a phosphono group-containing group are preferable, and a hydroxyl group-containing group and a carbonyl group-containing group are more preferable, and a carbonyl group-containing group is more preferable from the viewpoint of dispersion stability of this dispersion. More preferred.

The hydroxyl group-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-glycol group (-CH (OH) CH ₂ OH). ..
The carbonyl group-containing group is a group containing a carbonyl group (> C (O)), a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC (O) NH ₂ ), and an acid anhydride residue. Groups (-C (O) OC (O)-), imide residues (-C (O) NHC (O)-etc.) and carbonate groups (-OC (O) O-) are preferred, and acid anhydride residues. Is more preferable.
When the F polymer has a carbonyl group-containing group, the number of carbonyl group-containing groups in the F polymer is preferably 10 to 5000, more preferably 100 to 3000, and more preferably 800 per 1 × 10 ⁶ carbon atoms in the main chain. ~ 1500 pieces are more preferable. The number of carbonyl group-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, a polymer having an oxygen-containing polar group containing a TFE unit and a PAVE unit is preferable, and a polymer containing a unit based on a monomer having a TFE unit, a PAVE unit and an oxygen-containing polar group is more preferable, and all of them are used. It is more preferable that the polymer contains 90 to 99 mol%, 0.5 to 9.97 mol%, 0.01 to 3 mol% of these units in this order with respect to the unit.
Further, as the monomer having an oxygen-containing polar group, itaconic anhydride, citraconic anhydride or 5-norbornen-2,3-dicarboxylic acid anhydride (hereinafter, also referred to as “NAH”) is preferable.
Specific examples of such polymers include the polymers described in WO 2018/16644.
Not only are the particles of these F polymers excellent in dispersion stability, but they are also likely to be more densely and uniformly distributed in the molded product (polymer layer or the like) obtained from the present dispersion. Further, it is easy to form fine spherulites in the molded product, and it is easy to improve the adhesion with other components. As a result, it is easier to obtain a molded product having excellent various physical characteristics such as electrical characteristics.

Examples of the non-heat-meltable F polymer include non-heat-meltable PTFE.
The number average molecular weight of the non-thermally meltable PTFE is preferably 1 million to 100 million. The number average molecular weight of the non-thermally meltable PTFE is a value calculated based on the following formula (1).
Mn = 2.1 × 10 ¹⁰ × ΔHc- ^5.16 ... (1)
In the formula (1), Mn indicates the number average molecular weight of the non-thermally meltable PTFE, and ΔHc indicates the amount of heat of crystallization (cal / g) of the non-thermally meltable PTFE measured by the differential scanning calorimetry method. ..
When the number average molecular weight is in the range, the F polymer is less likely to be fibrillated, and the present dispersion is likely to have excellent dispersion stability.

In this dispersion, the D50 of F particles is preferably 0.1 to 25 μm. The D50 of the F particles is preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 8 μm or less. The D50 of the F particles is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 2 μm or more. In D50 in this range, the fluidity and dispersibility of F particles tend to be good.

From the viewpoint of the dispersion stability of the present dispersion, the bulk density of the F particles is preferably 0.15 g / m ² or more, more preferably 0.20 g / m ² or more. The bulk density of the F particles is preferably 0.50 g / m ² or less, more preferably 0.35 g / m ² or less.
The specific surface area of the F particles is preferably 1 to 8 m ² / g, more preferably 1 to 3 m ² / g.

One type of F particle may be used, or two or more types may be used. When two kinds of F particles are used, it is preferable to include non-heat-meltable F polymer particles and heat-meltable F polymer particles, and the non-heat-meltable PTFE (preferably having the above-mentioned number average molecular weight). Contains particles of 1 million to 100 million PTFE) and particles of an F polymer having a melting temperature of 200 to 320 ° C. (preferably a polymer having an oxygen-containing polar group, including the TFE units and PAVE units described above). Is more preferable.

In this case, the ratio of the content mass of both particles may be such that the content mass of the former particle is larger than the content mass of the latter particle, and the content mass of the former particle may be less than the content mass of the latter particle. ..
And it is more preferable that the content mass of the former particles is larger than the content mass of the latter particles.
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. Further, the ratio in this case is preferably 0.1% by mass or more, more preferably 1% by mass or more.
This dispersion liquid is not only easy to be excellent in dispersion stability, handleability and long-term storage stability, but is also easy to form an adhesive molded product having excellent physical characteristics based on PTFE.

Further, when the content mass of the former particles is smaller than the content mass of the latter particles, it is preferable from the viewpoint that it is 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. Further, the ratio is preferably 5% by mass or more, more preferably 10% by mass or more.

When the non-heat-meltable F polymer particles and the F polymer particles having a melting temperature of 200 to 320 ° C. are used, the D50 of the non-heat-melting PTFE particles is 0.1 to 1 μm, and the melting temperature is An embodiment in which the D50 of the particles of the F polymer having a temperature of 200 to 320 ° C. is 0.1 to 1 μm, the D50 of the particles of the non-thermally meltable PTFE is 0.1 to 1 μm, and the melting temperature is 200 to 320 ° C. It is preferable that the D50 of the polymer particles is 1 to 4 μm.

The F particles may contain a resin other than the F polymer or an inorganic filler, but the F polymer is preferably the main component. The content of the F polymer in the F particles is preferably 80% by mass or more, more preferably 100% by mass.
Examples of the resin include heat-resistant resins such as aromatic polyester, polyamide-imide, (thermoplastic) polyimide, polyphenylene ether, polyphenylene oxide, and maleimide. Examples of the inorganic filler include silicon oxide (silica), metal oxides (berylium oxide, cerium oxide, alumina, soda alumina, magnesium oxide, zinc oxide, titanium oxide, etc.), boron nitride, and magnesium metasilicate (steatite). .. At least a part of the surface of the inorganic filler may be surface-treated.
F particles containing a resin or inorganic filler other than the F polymer have a core-shell structure having the F polymer as the core and the resin or the inorganic filler other than the F polymer in the shell, or the F polymer as the shell and other than the F polymer. It may have a core-shell structure having a resin or an inorganic filler in the core. Such F particles are obtained, for example, by coalescing (collision, agglomeration, etc.) particles of an F polymer with particles of a resin or an inorganic filler other than the F polymer.

The imide-based resin P constituting the present dispersion improves the dispersion stability of the present dispersion and imparts flexibility such as bending resistance and UV absorption to the molded product obtained from the present dispersion. Further, when the present dispersion is applied to the surface of a resin film such as a polyimide film to form a polymer layer containing an F polymer, the polymer layer is imparted with properties such as adhesiveness and adhesion to the resin film.

The imide-based resin P includes a modified aromatic polyimide having a polar functional group such as an aromatic polyimide, an aromatic polyimide precursor (polyamic acid or a salt thereof), an aromatic polyamideimide, an aromatic polyamideimide precursor, and a carboxylic acid group. , Modified aromatic polyimide precursor, modified aromatic polyamideimide, modified aromatic polyamideimide precursor, aromatic polyetherimide or aromatic polyetherimide precursor.
Among them, aromatic polyimide or its precursor (polyamic acid or a salt thereof), aromatic polyamideimide or its precursor is preferable, and water-soluble aromatic polyimide precursor and water-soluble aromatic polyamide-imide precursor are more preferable. Water-soluble aromatic polyamide-imide precursors are more preferred.

Examples of the water-soluble aromatic polyimide precursor include a polyamic acid obtained by polymerizing a tetracarboxylic acid dianhydride and a diamine in a solvent, and a polyamic acid salt obtained by reacting the polyamic acid with aqueous ammonia or an organic amine. .. An aqueous solution of a polyamic acid can be prepared by dissolving the polyamic acid salt in water.
Examples of the tetracarboxylic acid dianhydride include pyromellitic acid anhydride and biphenyltetracarboxylic acid anhydride. Examples of the diamine include N, N'-diaminodiphenyl ether and p-diaminobenzene. Examples of the solvent include N-methylpyrrolidone and N, N-dimethylformamide.
Examples of the organic amine include primary amines such as methylamine, ethylamine, n-propylamine, 2-ethanolamine and 2-amino-2-methyl-1-propanol; dimethylamine, 2- (methylamino) ethanol, 2 -Secondary amines such as (ethylamino) ethanol; tertiary amines such as 2-dimethylaminoethanol, 2-diethylaminoethanol and 1-dimethylamino-2-propanol; 4 such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. Examples include grade ammonium salts.

The water-soluble aromatic polyamide-imide resin or its precursor is a polyamide-imide resin obtained by reacting diisocyanate and / or diamine with a tribasic acid anhydride (or tribasic acid chloride) as an acid component or a polyamide-imide resin thereof. Examples include precursors.
Examples of the diisocyanate include 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'-diphenylmethane diisocyanate, 3,3'-dimethoxybiphenyl-4, Examples thereof include 4'-diisocyanate, paraphenylenediocyanate, hexamethylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, tolylene diisocyanate and isophorone diisocyanate. These diisocyanates may be used alone or in combination of two or more.
From the viewpoint of improving the stability of the aromatic polyamide-imide resin, a block-type isocyanate in which an isocyanate group is stabilized with a blocking agent may be used as the diisocyanate. Examples of the blocking agent include alcohol, phenol, oxime and the like.

Examples of the diamine include 3,3'-dimethylbiphenyl-4,4'-diamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-. Examples thereof include diaminodiphenyl sulfone, xylylene diamine, phenylenediamine and isophoronediamine. These diamines may be used alone or in combination of two or more.

Examples of the tribasic acid anhydride include trimellitic acid anhydride, and examples of the tribasic acid chloride include trimellitic acid anhydride chloride. As the tribasic acid anhydride, trimellitic acid anhydride is preferable from the viewpoint of reducing the burden on the environment.

When producing an aromatic polyamide imide resin, in addition to the above-mentioned tribasic acid anhydride (or tribasic acid chloride), dicarboxylic acid, tetracarboxylic acid dianhydride and the like are used as acid components in the characteristics of the polyamideimide resin. May be used as long as it does not impair.
Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, adipic acid, and sebacic acid. Examples of the tetracarboxylic acid dianhydride include pyromellitic acid dianhydride, benzophenone tetracarboxylic acid dianhydride, and biphenyltetracarboxylic acid dianhydride. These may be used alone or in combination of two or more.
The total amount of carboxylic acids (dicarboxylic acid and tetracarboxylic acid) other than tribasic acid is preferably in the range of 0 to 30 mol% in the total carboxylic acid from the viewpoint of maintaining the characteristics of the polyamide-imide resin.

The ratio of diisocyanate and / or diamine and acid component (total amount of tribasic acid anhydride or tribasic acid anhydride chloride and dicarboxylic acid and tetracarboxylic acid dianhydride used as needed) is the polyamide produced. From the viewpoint of the molecular weight and the degree of cross-linking of the imide resin, the diisocyanate compound and / or the diamine compound is preferably 0.8 to 1.1 mol, and 0.95 to 1. It is more preferably 08 mol, and even more preferably 1.0 to 1.08 mol.

The water-soluble aromatic polyamide-imide resin or its precursor is obtained by copolymerizing the above diisocyanate and / or diamine with the above acid component in a polar solvent. Examples of the polar solvent include N-methyl-2-pyrrolidone, N-formylmorpholine, N-acetylmorpholine, N, N'-dimethylethyleneurea, N, N-dimethylacetamide, N, N-dimethylformamide, γ-butyrolactone and the like. Can be mentioned. A solvent having a high boiling point is preferable from the viewpoint of carrying out the amidimidization reaction at a high temperature for a short time, and N-methyl-2-pyrrolidone is generally used from the viewpoint of solubility. N-formylmorpholine is also preferable from the viewpoint of work environment and ease of safety management.
The amount of the polar solvent used is usually 50 to 500 parts by mass with respect to 100 parts by mass of the total amount of diisocyanate or diamine and the acid component, from the viewpoint of solubility of the obtained aromatic polyamide-imide resin or its precursor. Is preferable.
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 preferable to carry out the polymerization in an atmosphere such as nitrogen.

The water-soluble aromatic polyamideimide resin or its precursor is, for example, (1) a method of using an acid component and a diisocyanate component and / or a diamine component at a time and reacting them; (2) an acid component and a diisocyanate component and /. Alternatively, a method of reacting with an excess amount of the diamine component to synthesize an amidimide oligomer having an isocyanate group or an amino group at the terminal, and then adding an acid component to react with the isocyanate group and / or the amino group at the terminal; 3) After reacting the excess amount of the acid component with the diisocyanate component and / or the diamine component to synthesize an amidimide oligomer having an acid or acid anhydride group at the terminal, the diisocyanate component and / or the diamine component is added. It can be produced by a method of reacting with a terminal acid or an acid anhydride group;

The number average molecular weight (Mn) of the water-soluble aromatic polyamide-imide resin or its precursor is preferably 5000 or more, more preferably 10,000 or more, still more preferably 15,000 or more. On the other hand, Mn is preferably 50,000 or less, more preferably 30,000 or less, and even more preferably 25,000 or less. Within such a range, the solubility of the aromatic polyamide-imide resin or its precursor in water and the mechanical properties such as bending resistance of the molded product obtained from the present dispersion can be ensured.
The Mn of the aromatic polyamide-imide resin or its precursor is appropriately sampled at the time of polymerization and measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve to obtain the desired Mn. By polymerizing up to, it can be controlled within the above range.

Examples of the aromatic polyetherimide include an amorphous polymer having an imide bond and an ether bond in the main chain, and 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane and m-. A polycondensate with phenylenediamine is preferred. Examples of commercially available aromatic polyetherimides include "Ultem 1000F3SP" (manufactured by SABIC).

The acid value of the imide-based resin P is 20 to 100 mg / KOH. In this dispersion, the acid value of the imide-based resin P is adjusted to such a range to balance its functions. That is, when the acid value of the imide-based resin P is less than 20 mg / KOH, the reaction rate of the imide-based resin P when forming the molded product from the dispersion liquid is improved and the physical properties of the molded product are improved, but the dispersing action is performed. It decreases and the dispersion stability of the dispersion liquid is lowered. Further, when the acid value of the imide-based resin P exceeds 100 mg / KOH, the dispersion action of the imide-based resin P in the dispersion liquid is enhanced, but the reaction rate of the imide-based resin P when forming a molded product from the dispersion liquid is high. It deteriorates and deteriorates the physical properties of the molded product.
More specifically, when the acid value is 20 mgKOH / g or more, since it has many acidic groups, the imide-based resin P tends to be easily solubilized, and the imide-based resin P interacts with F particles and water. There is a tendency that the molded product formed from the present dispersion tends to have excellent adhesiveness to the base material. Further, when the acid value is 100 mgKOH / g or less, the storage stability of the present dispersion tends to be improved.
From these viewpoints, the acid value of the imide resin P is preferably 35 to 70 mgKOH / g. When the imide-based resin P has an acid anhydride group, the acid value when the acid anhydride group is opened is defined as the acid value of the imide-based resin P.

For the acid value, about 0.5 g of the imide resin P was collected, about 0.15 g of 1,4-diazabicyclo [2.2.2] octane was added thereto, and about 60 g of N-methyl-2-pyrrolidone was added. Add about 1 ml of ion-exchanged water and stir until the imide resin P is completely dissolved. This can be measured by titrating with a potentiometric titrator using a 0.05 mol / L ethanolic potassium hydroxide solution.

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

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

The total content of the F particles and the imide-based resin P in the dispersion liquid is preferably 20% by mass or more with respect to the total mass of the dispersion liquid. The total content is more preferably 30% by mass or more, further preferably 40% by mass or more. The total content is preferably 80% by mass or less. Specific examples of the preferred range of the total content include 30 to 80% by mass.
In this case, a molded product such as a coating film can be formed from the dispersion liquid with high uniformity, and the physical characteristics of the F polymer and the physical properties of the imide resin P are highly likely to be exhibited. That is, even if the content of the polymer component is in such a high range, the present dispersion is excellent in dispersion stability and can improve the physical characteristics of the molded product by the above-mentioned mechanism of action.

The ratio of the mass of the imide-based resin P to the mass of the F particles in the dispersion liquid is preferably 0.001 or more, more preferably 0.005 or more, and 0.01 or more. It is even more preferable to have it. The ratio is preferably 0.1 or less, more preferably 0.09 or less, still more preferably 0.05 or less. Specific examples of the preferred range of the ratio include 0.001 to 0.1.
When the ratio is in such a low range, the dispersion stability of the F particles is improved, and the physical properties of the molded product obtained from the present dispersion liquid are particularly likely to be improved. The reason is not always clear, but in this dispersion, the acid value of the imide-based resin P and the pH of the aqueous dispersion are in a predetermined range, and the imide-based resin P is a small amount component with respect to the F particles. The imide-based resin P is highly likely to function as a dispersant and binder for low-hydrophilic F particles, in other words, the imide-based resin P adheres to the surface of the F particles, and F is formed when the molded product is formed. It is considered that this is to promote the precise firing of the particles.

The content of water in this dispersion is preferably 40% by mass or more, more preferably 50% by mass or more. The water content is preferably 90% by mass or less, more preferably 80% by mass or less.
In such a range, the dispersion stability of the present dispersion is more likely to be improved by the above-mentioned mechanism of action.

The present dispersion may further contain a water-soluble dispersion medium other than water as the dispersion medium. As such a water-soluble dispersion medium, a water-soluble compound that is liquid at 25 ° C. classified as polar under atmospheric pressure is preferable, and for example, N, N-dimethylformamide, N, N-dimethylacetamide, 3-methoxy-N, Examples thereof include N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and N-methyl-2-pyrrolidone.

The dispersion may further contain a surfactant. When this dispersion contains a surfactant, the surfactant is nonionic, the hydrophobic moiety of the surfactant preferably has an acetylene group or a polysiloxane group, and the hydrophilic moiety is an oxyalkylene group or an alcohol. It preferably has a sex hydroxyl group.
That is, when the present dispersion further contains a surfactant, a nonionic surfactant having an alcoholic hydroxyl group is preferable, and a polyoxyalkylene alkyl ether, an acetylene-based surfactant or a silicone-based surfactant is more preferable. These surfactants may be used alone or in combination of two or more. From the viewpoint that the polyoxyalkylene alkyl ether stabilizes the long-term dispersibility of the F particles and improves the liquid physical properties such as the viscosity of the present dispersion, and the silicone surfactant improves the initial dispersibility of the F particles. , Polyoxyalkylene alkyl ether and silicone-based surfactant are preferably used in combination.
When the present dispersion further contains a surfactant, the amount thereof is preferably 1 to 15% by mass with respect to the total mass of the present dispersion. In this case, the affinity between the components is enhanced, and the dispersion stability of the present dispersion is likely to be further improved.

The silicone-based surfactant is a polyoxyalkylene-modified polydimethylsiloxane having a weight average molecular weight of 3000 or less and an HLB value of 1 to 18 calculated from the Griffin formula, which suppresses the load on the environment. It is preferable from the viewpoint of possible and stability in the present dispersion.

The polyoxyalkylene-modified polydimethylsiloxane (hereinafter, also referred to as "modified polydimethylsiloxane") is an organopolysiloxane having a polyoxyalkylene structure as a hydrophilic group and a polydimethylsiloxane structure as a hydrophobic group, and is linear. It is preferably a polymer.

The weight average molecular weight of the modified polydimethylsiloxane is 3000 or less, preferably 2500 or less, and more preferably 2000 or less. The weight average molecular weight is preferably 100 or more, more preferably 500 or more.
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 100 or more, more preferably 500 or more.
The molecular weight dispersion of the modified polydimethylsiloxane is preferably less than 2.0, more preferably 1.8 or less. 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, and particularly 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 28 mN / m or less, more preferably 26 mN / m or less. The static surface tension is preferably 15 mN / m or more, more preferably 20 mN / m or more.
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 may have a dimethylsiloxane unit (-(CH ₃ ) ₂ SiO _2/2- ) in the main chain, or may have a dimethylsiloxane unit in the side chain, and may have a main chain and a dimethylsiloxane unit. Both sides may have dimethylsiloxane units.
The modified polydimethylsiloxane contains a dimethylsiloxane unit in the main chain and a modified polydimethylsiloxane having an oxyalkylene group in the side chain, or a modified polydimethylsiloxane having a dimethylsiloxane unit in the main chain and an oxyalkylene group at the end of the main chain. Didimethylsiloxane is preferred.

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

Since the modified polydimethylsiloxane has a small weight average molecular weight and an HLB value in a predetermined range, it can be said that its hydrophobicity and hydrophilicity are highly balanced. It is considered that such modified polydimethylsiloxane is likely to enhance the interaction with F particles, and as a result, the dispersion stability of the present dispersion is considered to be improved.
Further, since the modified dimethylsiloxane is excellent in thermal decomposition property, it is easily decomposed when the present dispersion is heated to form a calcined product. As a result, the fired product tends to have high physical characteristics based on the F polymer.

Polyoxyalkylene alkyl ethers include polyoxyethylene decyl ether, polyoxyethylene undecyl ether, polyoxyethylene dodecyl ether, polyoxyethylene tridecyl ether, polyoxyethylene tetradecyl ether, triethylene glycol monomethyl ether, and polyethylene glycol trimethylnonyl. Ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate are More preferably, it is polyoxyethylene decyl ether, polyoxyethylene undecyl ether, polyoxyethylene dodecyl ether, polyoxyethylene tridecyl ether, or polyoxyethylene tetradecyl ether.

The polyoxyalkylene alkyl ether can be obtained as a commercial product, specifically, "Tergitol TMN-100X" (manufactured by Dow Chemical Co., Ltd.); "Lutensol TO8", "Lutensol XL70", "Lutensol XL80", "Lutensol XL90", "Lutensol XL90". "Lutensol XP80", "Lutensol M5" (above, manufactured by BASF); "New Call 1305", "New Call 1308FA", "New Call 1310" (above, manufactured by Nippon Emulsifier); "Leocol TDN-90-80" , "Leocol SC-90" (above, manufactured by Lion Specialty Chemicals Co., Ltd.).

When this dispersion contains a surfactant, the polyoxyalkylene alkyl ether can be obtained as a commercially available product, and specific examples thereof include "Tergitol TMN-100X" (manufactured by Dow Chemical Co., Ltd.); "Lutensol TO8".
When the dispersion further contains a surfactant, the amount thereof is preferably 0.1% by mass or more, more preferably 0.1% by mass or more, based on the total mass of the dispersion. The amount is preferably 15% by mass or less.

The dispersion may further contain at least one nonionic polymer selected from the group consisting of a polyvinyl alcohol-based polymer, a polyvinylpyrrolidone-based polymer, and a polysaccharide. It is extremely preferable that the nonionic polymer is a water-soluble polymer. In this case, the interaction between the water-soluble polymer and the imide-based resin P improves not only the dispersion stability of the dispersion but also the rheological characteristics, and the handleability of the dispersion such as film formation is further improved. Cheap. As a result, it is easier to form a thick molded product or a molded product having an arbitrary shape from the present dispersion liquid. In particular, if the water-soluble polymer has a nonionic hydroxyl group, this tendency tends to be remarkable.
The polyvinyl alcohol-based polymer may be a partially acetylated or partially acetalized polyvinyl alcohol.
Examples of the polysaccharide include glycogens, amicropectins, dextrins, glucans, fructans, chitins, amyloses, agaroses, amicropectins, and celluloses. Examples of celluloses include methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl cellulose.

As the water-soluble nonionic polymer, nonionic polysaccharides are preferable, nonionic celluloses are more preferable, and hydroxymethyl cellulose, hydroxyethyl cellulose or hydroxypropyl cellulose is further preferable.
Specific examples of such nonionic polysaccharides include "Sunrose (registered trademark)" series (manufactured by Nippon Paper Industries), "Metroise (registered trademark)" series (manufactured by Shin-Etsu Chemical Co., Ltd.), and "HEC CF grade" (manufactured by Shin-Etsu Chemical Co., Ltd.). Sumitomo Seika Co., Ltd.).

When the dispersion further contains a water-soluble nonionic polymer, the amount thereof is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, based on the total mass of the dispersion. .. The amount is preferably less than 1% by mass. The ratio of the mass of the water-soluble nonionic polymer to the mass of the F particles in this dispersion is preferably 0.001 or more, more preferably 0.01 or more. Further, the previous ratio is preferably less than 0.1.
As described above, the interaction between the water-soluble polymer and the imide-based resin P makes it easy to obtain the effect of improving the liquid physical characteristics and the film-forming property of the present dispersion by containing a small amount of the water-soluble polymer. As a result, the residual amount of the water-soluble polymer in the molded product obtained from the present dispersion is reduced, and a molded product having better physical properties such as electrical characteristics can be easily obtained from the present dispersion. This tendency is particularly remarkable when the water-soluble polymer has a nonionic hydroxyl group.

The present dispersion may further contain amine or ammonia. Amine or ammonia also has a role as a pH adjuster and is considered to contribute to the improvement of dispersion stability and storage stability of this dispersion. When the present dispersion further contains amine or ammonia, the amount thereof may be an amount such that the pH of the present dispersion is 5 to 10.

Examples of the amine include dimethylamine, diethylamine, diisopropylamine, diethanolamine, triethanolamine, tripropanolamine, triethylamine, triamylamine, pyridine and N-methylmorpholine.
In this case, a pH buffer may be further added to stabilize the pH of the liquid composition.
Examples of the pH buffer include tris (hydroxymethyl) aminomethane, ethylenediaminetetraacetic acid, ammonium hydrogencarbonate, ammonium carbonate and ammonium acetate.

The present dispersion may further contain a resin material other than the F polymer and the imide-based resin P from the viewpoint of improving the adhesiveness and low linear expansion property of the molded product formed from the present dispersion. Such a resin material may be thermosetting or thermoplastic, may be modified, may be dissolved in the present dispersion, or may be dispersed without being dissolved.
Examples of such resin materials include acrylic resin, phenol resin, liquid crystal polyester, liquid crystal polyester amide, polyolefin resin, modified polyphenylene ether, polyfunctional cyanate ester resin, polyfunctional maleimide-cyanic acid ester resin, polyfunctional maleimide, and styrene. Aromatic elastomers such as elastomers, vinyl ester resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, melamine-urea cocondensate resins, polycarbonates, polyarylates, polysulfones, polyallylsulfones, aromatic polyamides, aromatic poly Examples thereof include ether amide, polyphenylen sulphide, polyallyl ether ketone, polyphenylene ether, epoxy resin and the like.
When the present dispersion further contains a resin material, the content thereof is preferably 40% by mass or less with respect to the total mass of the present dispersion.

Preferred embodiments of the resin material include aromatic polymers. The aromatic polymer is preferably polyphenylene ether or an aromatic elastomer (styrene elastomer or the like). In this case, not only the adhesiveness and low linear expansion property of the molded product formed from the present dispersion are further improved, but also the liquid properties (viscosity, thixotropic ratio, etc.) of the present dispersion can be balanced, so that the handling property is easy to handle. Is easy to improve.
Here, examples of the styrene elastomer include copolymers of styrene and conjugated diene or (meth) acrylic acid esters (styrene-butadiene rubber, styrene-based core-shell type copolymers, styrene-based block copolymers, etc.), and rubber and plastic. Styrene elastomers having both properties, which are plasticized by heating and exhibit flexibility, are preferred.

The dispersion may further contain an inorganic filler. In this case, the molded product produced from the present dispersion tends to be excellent in electrical characteristics and low linear expansion. Further, even if the present dispersion liquid contains an inorganic filler, it has excellent dispersion stability due to the above-mentioned mechanism of action, and it is easy to obtain a dense molded product. Therefore, it is easy to produce a molded product having the physical characteristics of the F polymer, the imide-based resin P, and the inorganic filler from the present dispersion liquid containing the inorganic filler.
The inorganic filler is preferably a nitride filler or an inorganic oxide filler, preferably a boron nitride filler, an aluminum nitride filler, a beryllia filler (a filler of an oxide of beryllium), and a silicate filler (silica filler, a wollastonite filler, and a talc filler). ) Or a metal oxide (cerium oxide, aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, etc.) filler is more preferable, and a silica filler is further preferable.
At least a part of the surface of the inorganic filler is a silane coupling agent (3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3). -It is preferable that the surface is treated with (methacryloxypropyltriethoxysilane, 3-isocyandiapropyltriethoxysilane, etc.).

The D50 of the inorganic filler is preferably 20 μm or less, more preferably 10 μm or less. The D50 is preferably 0.01 μm or more, more preferably 0.1 μm or more.
The shape of the inorganic filler may be granular, needle-shaped (fibrous), or plate-shaped. Specific shapes of the inorganic filler include spherical, scaly, layered, leafy, apricot kernel, columnar, chicken crown, equiaxed, leafy, mica, block, flat plate, wedge, rosette, and mesh. The shape and the prismatic shape can be mentioned.
As the inorganic filler, one kind may be used alone, or two or more kinds may be used in combination. When the present dispersion further contains an inorganic filler, the amount thereof is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, based on the total mass of the dispersion.

Suitable specific examples of the inorganic filler include silica filler (“Admafine (registered trademark)” series manufactured by Admatex Co., Ltd.), zinc oxide surface-treated with an ester such as propylene glycol dicaprate (Sakai Chemical Industry Co., Ltd.). "FINEX (registered trademark)" series, etc.), spherical molten silica ("SFP (registered trademark)" series, etc. manufactured by Denka), titanium oxide coated with polyhydric alcohol and inorganic substances (manufactured by Ishihara Sangyo Co., Ltd.) "Typake (registered trademark)" series, etc.), rutile-type titanium oxide surface-treated with alkylsilane ("JMT (registered trademark)" series manufactured by Teika, etc.), hollow silica filler ("E" manufactured by Pacific Cement Co., Ltd.) -SPHERES "series, Nittetsu Mining Co., Ltd." Sirinax "series, Emerson & Cumming Co., Ltd." Ecocos Fire "series, etc.), Tarkufiller (Nippon Tarku Co., Ltd." SG "series, etc.), Steatite Filler ("Steatite Filler" (, etc.) Nippon Tark's "BST" series, etc.), Titanium dioxide filler (Showa Denko's "UHP" series, Denka's "Denka Boron Night Ride" series ("GP", "HGP" grade), etc.) Can be mentioned.

In addition to the above-mentioned components, the present dispersion contains a tyxonicity-imparting agent, a viscosity modifier, an antifoaming agent, a silane coupling agent, a dehydrating agent, a plasticizer, a weathering agent, and an antioxidant, as long as the effects of the present invention are not impaired. Other components such as agents, heat stabilizers, lubricants, antistatic agents, whitening agents, colorants, conductive agents, mold release agents, surface treatment agents, flame retardants, and various fillers may be further contained.

The viscosity of this dispersion is preferably 10 mPa · s or more, more preferably 30 mPa · s or more, and even more preferably 50 mPa · s or more. The viscosity of this dispersion is preferably 3000 mPa · s or less, more preferably 1000 mPa · s or less, and even more preferably 800 mPa · s or less. The viscosity of this dispersion is preferably 50 to 3000 mPa · s, more preferably 50 to 1000 mPa · s.

The thixotropic ratio of this dispersion is preferably 1.0 or more. The thixotropic ratio of this dispersion is preferably 3.0 or less, more preferably 2.0 or less. In this case, the present dispersion is excellent in coatability and homogeneity, and it is easy to form a more dense molded product (polymer layer or the like).
The pH of this dispersion is 5-10. In this dispersion, the function of the imide-based resin P is balanced by adjusting the pH within such a range. That is, when the pH of the dispersion liquid is less than 5, the reactivity of the imide-based resin P is increased, but the dispersion action thereof is lowered and the dispersion stability of the dispersion liquid is lowered. Further, when the pH of the dispersion liquid is more than 10, the dispersion action of the imide-based resin P is enhanced, but the reactivity thereof is lowered, and the physical properties of the molded product obtained from the dispersion liquid are lowered. The pH of this dispersion is preferably 7-9. In this case, the hue and long-term storage stability of this dispersion are likely to be excellent.

In this dispersion, the dispersion layer ratio is preferably 60% or more, more preferably 70% or more, and further preferably 80% or more. Here, the dispersion layer ratio means that when a dispersion liquid (18 mL) is placed in a screw tube (internal volume: 30 mL) and allowed to stand at 25 ° C. for 14 days, the entire dispersion liquid in the screw tube after standing has been allowed to stand. It is a value calculated by the following formula from the height and the height of the sedimentation layer (dispersion layer). If the sedimentation layer is not confirmed after standing and there is no change in the state, it is assumed that the height of the entire dispersion liquid does not change, and the dispersion layer ratio is 100%.
Dispersion layer ratio (%) = (height of sedimentation layer) / (height of the entire dispersion) × 100

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

This dispersion can be prepared by mixing F particles, an imide resin P, and water as a dispersion medium. As a mixing method, F particles and imide-based resin P are added to water all at once or sequentially and mixed; F particles and water, and imide-based resin P and water are mixed in advance, respectively, and a mixture of the two obtained is obtained. A method of further mixing; and the like. In this dispersion, F particles are dispersed in water in advance, and then the imide resin P is added as it is (directly) or in a state of being mixed with water and mixed to prepare the dispersion, or water. It is advantageous to prepare by adding the imide-based resin P to the water in advance and then adding the F particles as they are (directly) or in a state of being mixed with water and mixing them from the viewpoint of more uniformly dispersing the F particles. Yes, preferred. When a surfactant, other resin material or an inorganic filler is further contained in the dispersion liquid, it is added at the same time when the F particles are pre-dispersed in water, or it is added to water before the F particles are dispersed. It is preferable to add it in advance.

As a mixing method when preparing this dispersion, for example, a stirring device equipped with blades (stirring blades) such as propeller blades, turbine blades, paddle blades, and shell-shaped blades on a single axis or multiple axes, a henshell mixer, and pressurization. Stirring with a kneader, Banbury mixer or planetary mixer; ball mill, attritor, basket mill, sand mill, sand grinder, dyno mill (bead mill using crushing medium such as glass beads or zirconium oxide beads), dispermat, SC mill, spike mill Or mixing with a disperser using media such as an agitator mill; high-pressure homogenizer such as microfluidizer, nanomizer, ultimateizer, ultrasonic homogenizer, resolver, disper, high-speed impeller disperser, rotation / revolution agitator, thin-film swirl high-speed mixer. Etc., mixing using a disperser that does not use media can be mentioned.

A preferred embodiment of the method for producing the present dispersion is an embodiment in which F particles and a composition containing water are kneaded to obtain a kneaded product, and the kneaded product and water are further mixed. At that time, the imide-based resin P may be added to the composition or may be added when the kneaded product and water are further mixed, and the former is preferable. That is, it is preferable to knead the composition containing F particles, the imide resin P, and water to obtain a kneaded product, and further mix the kneaded product and water.
The kneading can be carried out by the above-mentioned mixing method, and it is preferable to use a Henschel mixer, a pressurized kneader, a Banbury mixer, a rotation / revolution stirrer or a planetary mixer, and more preferably a planetary mixer.
The planetary mixer has a biaxial stirring blade that rotates and revolves with each other, and has a structure for stirring and kneading the kneaded material in the stirring tank. Therefore, there is little dead space in the stirring tank where the stirring blades do not reach, the load on the blades can be reduced, and the composition can be highly kneaded. That is, it is possible to knead the F particles while suppressing the aggregation of the F particles while wetting the F particles with water while highly interacting the F particles with the imide-based resin P. Therefore, when the kneaded product is further mixed with water, the dispersion stability is improved. It is easy to obtain an excellent dispersion. Further, 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 product (polymer layer or the like) having excellent surface smoothness and uniformity.

The content of F particles in the composition is preferably 20% by mass or more, more preferably 40% by mass or more, based on the total mass of the composition. The content of F particles is preferably 90% by mass or less. The content of the imide-based resin P in the composition is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, based on the total mass of the composition. The content of the imide-based resin P is preferably 10% by mass or less.
The total content of the F particles and the imide-based resin P in the composition is preferably 40% by mass or more, more preferably 60% by mass or more, based on the total mass of the composition. The total content is preferably 90% by mass or less.

The ratio of the mass of the imide-based resin P to the mass of the F particles in the composition is preferably 0.001 or more, more preferably 0.005 or more, and more preferably 0.01 or more. Is even more preferable. The ratio is preferably 0.1 or less, more preferably 0.09 or less, still more preferably 0.05 or less.
When the content of the F particles, the content of the imide-based resin P, or the ratio is in such a low range, the F particles and the imide-based resin P can be kneaded while highly interacting with each other in the kneading of the composition. Therefore, when the kneaded product is further mixed with water, the dispersion liquid having excellent dispersion stability in which the ratio of the mass of the imide-based resin P to the mass of the F particles is in the range of 0.001 to 0.1 is obtained. Easy to obtain.

The kneaded product is a semi-solid or solid solidified product, and is preferably a kneaded paste or a kneaded powder. The kneaded paste is a kneaded product having fluidity and viscosity, and the kneaded powder is a kneaded product in a lumpy and clay-like state.
The viscosity of the kneaded paste is preferably 800 to 100,000 mPa · s, more preferably 1000 to 10,000 mPa · s or more.
The water content of the dough is preferably 50% by mass or less, and preferably 40% by mass or less. The water content of the dough is preferably 20% by mass or more, and more preferably 25% by mass or more.

Further, in this embodiment, when a surfactant, another resin material or an inorganic filler is further contained in the present dispersion, these may be added to the composition, and the mixture may be added at the time of mixing the kneaded product and water. You may.
In this dispersion containing other resin materials and inorganic fillers, F particles, other resin materials or inorganic fillers, and a composition containing water are kneaded to obtain a kneaded product, and the kneaded product and the imide-based resin P are obtained. And may be obtained by mixing with a mixture containing water. In this case, the dispersion stability and long-term storage stability of the present dispersion are likely to be improved.

This dispersion is also excellent in dispersion stability and long-term storage stability, and forms a molded product that has excellent flexibility such as bending resistance, that is, crack resistance, and exhibits strong adhesiveness to a substrate. can.
This dispersion is applied to at least one surface of the substrate to form a liquid film, the liquid film is heated to remove the dispersion medium to form a dry film, and the dry film is further heated to form an F polymer. By firing, a laminate having a polymer layer containing the F polymer and the imide resin P (hereinafter, also referred to as “F layer”) on the surface of the base material (hereinafter, also referred to as “main laminate”) can be obtained. ..
Further, when the present dispersion is applied to both surfaces of the base material and heated to bake the F polymer, a laminate having F layers on both sides of the base material layer composed of the base material can be obtained.

As the base material, a metal substrate (copper, nickel, aluminum, titanium, metal foil such as an alloy thereof, etc.), a resin film (tetrafluoroethylene polymer, polyimide, polyarylate, polysulfone, polyallylsulfone, polyamide, polyether, etc.) It is a heat-resistant resin film containing one or more of heat-resistant resins such as amide, polyphenylene sulfide, polyallyl ether ketone, polyamideimide, liquid crystal polyester, and liquid crystal polyester amide, and is a multilayer film even if it is a single-layer film. Prepreg (precursor of fiber-reinforced resin substrate), ceramic substrate (ceramic substrate such as silicon carbide, aluminum nitride, silicon nitride), and glass substrate. Of these, a resin film is preferable, and it is more preferable that the resin constituting the resin film is a polyimide resin.
This dispersion is suitably used for forming an F layer by applying it to at least one surface of a resin film and drying it.
Examples of the shape of the base material include a planar shape, a curved surface shape, and an uneven shape. The shape of the base material may be foil-like, plate-like, film-like, or fibrous.

As a method of applying the present dispersion liquid to the surface of the base material, any method may be used as long as a stable liquid film (wet film) composed of the present dispersion liquid is formed on the surface of the resin film (base material). Examples thereof include a droplet ejection method and a dipping method, and a coating method is preferable. If the coating method is used, a liquid film can be efficiently formed on the surface of the resin film with simple equipment.
The coating methods include spray method, roll coat method, spin coat method, gravure coat method, micro gravure coat method, gravure offset method, knife coat method, kiss coat method, bar coat method, die coat method, fountain Mayer bar method, and slit coat. The method, the slot die coat method, and the dip coat method can be mentioned.

When the liquid film is dried, the liquid film is heated at a temperature at which the dispersion medium (water) volatilizes, and the dry film is formed on the surface of the resin film. The heating temperature in such drying is preferably 100 to 200 ° C. Air may be blown in the step of removing the dispersion medium.
At the time of drying, the dispersion medium does not necessarily have to be completely volatilized, and may be volatilized to the extent that the layer shape after holding is stable and the self-supporting film can be maintained.

When firing the F polymer, it is preferable to heat the dry film at a temperature equal to or higher than the melting temperature of the F polymer. The heating temperature is preferably 380 ° C. or lower.
Examples of each heating method include a method using an oven, a method using a ventilation drying furnace, and a method of irradiating heat rays such as infrared rays. The heating may be performed under either normal pressure or reduced pressure. The heating atmosphere may be any of an oxidizing gas atmosphere (oxygen gas, etc.), a reducing gas atmosphere (hydrogen gas, etc.), and an inert gas atmosphere (helium gas, neon gas, argon gas, nitrogen gas, etc.). ..
The heating time is preferably 0.1 to 30 minutes, more preferably 0.5 to 20 minutes.
By heating under the above conditions, the F layer can be suitably formed while maintaining high productivity.

The thickness of the F layer is preferably 0.1 to 150 μm, more preferably 10 μm or more. When the base material layer is a metal foil, the thickness of the F layer is preferably 10 to 30 μm. When the base material layer is a resin film, the thickness of the F layer is preferably 10 to 150 μm, more preferably 15 to 50 μm.
The peel strength between the F layer and the base material layer is preferably 10 N / cm or more, more preferably 15 N / cm or more. The peel strength is preferably 100 N / cm or less. By using this dispersion, such a laminate can be easily formed without impairing the physical properties of the F polymer in the F layer.

The porosity of the F layer is preferably 30% or less, more preferably 20% or less. The porosity is preferably 0.1% or more, more preferably 1% or more. From this dispersion, it is easy to form an F layer with a low porosity. In particular, even when the porosity of the dry film is 1% or more, it is easy to form an F layer having a low porosity. The void ratio is determined by image processing to determine the void portion of the F layer from the SEM photograph of the cross section of the molded product observed using a scanning electron microscope (SEM), and the area occupied by the void portion is the area occupied by the F layer. It is the ratio (%) divided by the area. The area occupied by the void portion is obtained by approximating the void portion to a circle.

The present dispersion may be applied to only one surface of the base material, or may be applied to both sides of the base material. In the former, a base material layer composed of the base material and the present laminate having an F layer on one surface of the base material layer are obtained, and in the latter, a base material layer composed of the base material and a base material layer are obtained. The present laminate having the F layer on both surfaces of the base material layer can be obtained. Since the latter laminated body is less likely to warp, it is excellent in handleability during its processing.
Specific examples of the present laminate include a metal foil, a metal-clad laminate having an F layer on at least one surface of the metal foil, a polyimide film, and a multilayer film having an F layer on both surfaces of the polyimide film. Can be mentioned. Since these laminated bodies are excellent in various physical characteristics such as electrical characteristics, they are suitable as printed circuit board materials and the like, and can be used for manufacturing flexible printed circuit boards and rigid printed circuit boards.

In this laminate having F layers on both sides of the base material layer, the present dispersion is applied to one surface of the base material and heated to remove the liquid dispersion medium, and the present dispersion is applied to the other surface of the base material. It is preferably obtained by applying, heating to remove the liquid dispersion medium, and further heating to fire the F polymer to form each F layer.

Further, in the present laminate having the F layer on both sides of the base material layer, the present dispersion liquid is applied to both surfaces of the base material, heated to remove the liquid dispersion medium, and further heated to bake the F polymer. Alternatively, the F layers on both surfaces may be formed at the same time.
In this case, in the present laminate having the F layer on both sides of the base material layer, the base material is immersed in the main dispersion liquid to be applied to both surfaces of the base material, and then passed through a firing furnace and heated. It is preferable to obtain it. Specifically, it is more preferable to immerse the base material in the main dispersion liquid and then heat the base material by passing it through a firing furnace while pulling it up from the main dispersion liquid.
The direction in which the base material is pulled up and passed through the firing furnace is preferably vertically upward. In this case, a smooth F layer is likely to be formed. After pulling up the base material vertically upward, the base material may be further heated while being pulled down vertically, or the base material may be pulled down vertically without heating to take over the base material.
Further, the amount of the present dispersion liquid to be applied to the base material can be adjusted by passing the base material to which the present dispersion liquid is attached between a pair of rolls.
Such a laminated body can be suitably manufactured by using an apparatus having a dip coater and a firing furnace. Examples of the firing furnace include a vertical firing furnace. Further, as such a device, a glass cloth coating device manufactured by Tabata Machinery Co., Ltd. can be mentioned.

Here, the outermost surface of the base material may be further surface-treated in order to further improve its low line expandability and adhesiveness.
Examples of the surface treatment method include annealing treatment, corona treatment, plasma treatment, ozone treatment, excimer treatment, and silane coupling treatment.
The conditions for the annealing treatment are preferably 120 to 180 ° C., a pressure of 0.005 to 0.015 MPa, and a time of 30 to 120 minutes.
Examples of the gas used for the plasma treatment include oxygen gas, nitrogen gas, rare gas (argon, etc.), hydrogen gas, ammonia gas, and vinyl acetate. One type of these gases may be used, or two or more types may be used in combination.
The ten-point average roughness of the surface of the base material is preferably 0.01 to 0.05 μm.

This laminate in which the base material layer is a resin film (preferably a polyimide film) is useful as a release film or a carrier film. Since this laminated body has excellent adhesiveness between the F layer and the base material layer and is difficult to delaminate, it can be used repeatedly as a carrier film. Further, since the F layer has excellent heat resistance, the releasability does not easily deteriorate even after repeated use.

Specifically, a dispersion liquid or varnish containing a resin or an inorganic filler is applied to the surface of the F layer of the laminated body and dried to form a coating film, and then the main laminated body is peeled off from the coating film. Then, an independent coating film can be obtained. For example, after forming the coating film on the surface of the F layer of the present laminate, the coating film side of the present laminate having such a coating film and another base material are bonded to each other, and the present laminate is peeled off. A laminate of the base material and the coating film is obtained.
When forming a coating film on the surface of the F layer of the present laminate, for example, it may be heated at a temperature equal to or lower than the melting point of the F polymer during drying. Since this laminate has excellent heat resistance, it is not easily deformed even after repeated heat treatment.

Specifically, the present laminate is a carrier film for forming a ceramic green sheet, a carrier film for forming a secondary battery, a carrier film for forming a solid polymer electrolyte membrane, and a carrier film for forming a catalyst of a solid polymer electrolyte membrane. It is useful as.
When the present laminate is used as a carrier film, the ratio of the thickness of the end portion to the thickness of the central portion of the present laminate is preferably 1.1 or less from the viewpoint of obtaining the coating film having a uniform thickness. .07 or less is more preferable, and 1.04 or less is more preferable. The thickness ratio is 1 or more.

Another substrate may be further laminated on the outermost surface of the laminated body.
Examples of other substrates include a metal substrate, a heat-resistant resin film, a prepreg which is a precursor of a fiber-reinforced resin plate, a laminate having a heat-resistant resin film layer, and a laminate having a prepreg layer.
The prepreg is a sheet-like substrate in which a base material (tow, woven fabric, etc.) of reinforcing fibers (glass fibers, carbon fibers, etc.) is impregnated with a thermosetting resin or a thermoplastic resin.
Examples of the metal substrate include the above-mentioned metal substrate. The heat-resistant resin film is a film containing one or more heat-resistant resins, and examples of the heat-resistant resin include the above-mentioned resins.

Examples of the laminating method include a method of heat-pressing the main laminated body with another substrate.
When the other substrate is a prepreg, the hot press conditions are preferably such that the temperature is 120 to 400 ° C., the atmospheric pressure is a vacuum of 20 kPa or less, and the press pressure is 0.2 to 10 MPa. Since this laminate has an F layer having excellent electrical characteristics, it is suitable as a printed circuit board material, and specifically, it can be used as a flexible metal-clad laminate or a rigid metal-clad laminate for manufacturing a printed circuit board. It can be suitably used for manufacturing a flexible printed circuit board as a flexible metal-clad laminate.

This laminated body (metal foil with F layer) in which the base material layer is a metal foil, and a metal-clad laminate (resin film) in which a metal foil is further laminated on the main laminated body having an F layer in which the base material layer is a resin film. And the metal foil with F layer) is etched to form a transmission circuit to obtain a printed substrate. Specifically, a method of etching a metal foil to process it into a predetermined transmission circuit, or a method of processing a metal foil into a predetermined transmission circuit by an electrolytic plating method (semi-additive method (SAP method), MSAP method, etc.). Can be used to manufacture printed circuit boards.
A printed circuit board manufactured from a metal foil with an F layer and a resin film and a metal foil with an F layer has a transmission circuit formed from the metal foil and an F layer in this order. Specific examples of the configuration of the printed circuit board include a transmission circuit / F layer / prepreg layer, a transmission circuit / F layer / prepreg layer / F layer / transmission circuit, a transmission circuit / F layer / polyimide film layer, and a transmission circuit / F layer /. Examples include a polyimide film layer / F layer / transmission circuit.
In the manufacture of such a printed circuit board, an interlayer insulating film may be formed on the transmission circuit, a solder resist may be laminated on the transmission circuit, or a coverlay film may be laminated on the transmission circuit. These interlayer insulating films, solder resists and coverlay films may be formed with the present dispersion.

Since this laminate in which the base material layer is a metal substrate is excellent in insulating property and heat dissipation property, it is also useful as a heat dissipation board, and can be particularly preferably used as a board for mounting a power semiconductor.
In such a case, the shape of the base material is preferably plate-like, and the base material is preferably a copper plate or an aluminum plate. The thickness of the base material is preferably 0.1 to 3 mm.
In the production of the present laminate in such a case, the slit coating method is preferable as a method of applying the present dispersion liquid to the base material.
As the F polymer in such a case, an F polymer having a melting temperature of 200 to 320 ° C. is preferable, and a polymer having an oxygen-containing polar group containing the above-mentioned TFE unit and PAVE unit is more preferable.

As the imide-based resin P in such a case, an aromatic polyimide, an aromatic polyimide precursor, an aromatic polyamideimide or an aromatic polyamide-imide precursor is preferable.
In such a case, it is preferable that the F layer further contains an inorganic filler. As the inorganic filler, a boron nitride filler, an aluminum nitride filler or an aluminum oxide filler is preferable.
That is, in the present laminate used as the heat dissipation substrate, the F polymer is a polymer having an oxygen-containing polar group containing the above-mentioned TFE unit and PAVE unit, and the imide-based resin P is an aromatic polyimide or an aromatic polyimide precursor. The body, aromatic polyamideimide or aromatic polyamideimide precursor is preferable, and the F layer thereof preferably contains a boron nitride filler, an aluminum nitride filler or an aluminum oxide filler. In this case, the insulation and heat dissipation of the laminated body as a heat dissipation substrate are particularly likely to be improved.

When the present laminated body is used as a heat dissipation substrate, it is preferable that the present laminated body is processed into a laminated body having a metal layer, an F layer, and a metal layer in this order. Such a laminate may be obtained by thermocompression-bonding a metal substrate to the surface of the F layer of the present laminate, laminating the two present laminates so that the F layers face each other, and thermocompression-bonding the F layer. The latter is preferable.
As a method of thermocompression bonding, a hot press is preferable.
The thicknesses of the two metal layers in such a laminate may be the same or different. Further, the metals in the two metal layers may be the same or different.
For example, the F layer of the main laminate having an F layer on the surface of an aluminum plate having a thickness of 1 mm and the F layer of the main laminate having an F layer on the surface of a copper plate having a thickness of 0.5 mm are heat-pressed. By crimping, an aluminum plate, an F layer, and a copper plate are provided in this order, and a laminate having two metal layers having different thicknesses can be obtained.

This laminate and the laminate of this laminate and other substrates are useful as antenna parts, printed substrates, aircraft parts, automobile parts, sports equipment, food industry supplies, paints, heat dissipation parts, cosmetics, etc. , Specifically, wire coating materials (aircraft wires, etc.), electrical insulating tapes, insulating tapes for oil drilling, materials for printed substrates, separation membranes (precision filtration membranes, ultrafiltration membranes, back-penetration membranes, ion exchange). Membranes, dialysis membranes, gas separation membranes, etc.), electrode binders (for lithium secondary batteries, fuel cells, etc.), copy rolls, furniture, automobile dashboards, covers for home appliances, sliding members (load bearings, sliding shafts, etc.) , Valves, bearings, gears, cams, belt conveyors, food transport belts, etc.), tools (shovels, shavings, cuttings, saws, etc.), boilers, hoppers, pipes, ovens, baking molds, chutes, dies, toilet bowls, container coverings. Materials, mounted heat dissipation boards for power devices, transistors, thyristors, rectifiers, transformers, power MOS FETs, CPUs, heat dissipation fins, metal heat dissipation plates, blades for windmills, wind power generation equipment, aircraft, etc., personal computer and display housings, electronic devices It is useful as a member, interior / exterior member of an automobile, a seal member such as a processing machine or vacuum oven that heat-treats under low oxygen, a plasma processing device, a heat dissipation part in a processing unit such as a sputter or various dry etching devices, and an electromagnetic wave shielding member. be.

Although the present dispersion, the method for producing the present dispersion, and the present laminate have been described above, the present invention is not limited to the configuration of the above-described embodiment. For example, the present dispersion and the present laminate may be added to any other configuration or may be replaced with any configuration exhibiting the same function in the configuration of the above embodiment. In addition, the method for producing the present dispersion may additionally have any other step in the configuration of the above embodiment, or may be replaced with any step that produces the same action.

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto.
1. 1. Details of each component [F particles]
F particle 1: Contains 97.9 mol%, 0.1 mol%, and 2.0 mol% of TFE units, NAH units, and PPVE units in this order, and contains carbonyl group-containing groups per 1 × 10 ⁶ main chain carbon atoms. Particles (D50: 2.1 μm) consisting of 1000 polymers (melting temperature: 300 ° C)
F particle 2: A polymer containing 97.5 mol% and 2.5 mol% of TFE units and PPVE units in this order and having 25 carbonyl group-containing groups per 1 × 10 ⁶ main chain carbon atoms (melting temperature 305 ° C.). ) Particles (D50: 1.8 μm)
F particle 3: Particles made of non-heat-meltable PTFE (D50: 0.2 μm)
[F dispersion liquid]
F dispersion liquid 1: Water dispersion liquid containing 60% by mass of F particles 3 (“AD-911E” manufactured by AGC).
[Varnish of imide resin]
Varnish 1: Water varnish containing a precursor (acid value: 50 mgKOH / g) of aromatic polyamide-imide (PAI1) [surfactant]
Surfactant 1: Polyoxyalkylene-modified polydimethylsiloxane having a dimethylsiloxane unit in the main chain and an oxyethylene group at the end of the main chain or the side chain (weight average molecular weight: 1600, dispersibility: 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 regulator]
Amine 1: Triethanolamine Acid 1: Formic acid [Nonionic polymer]
Polysaccharide 1: Hydroxyethyl cellulose (“HEC CF-Y” manufactured by Sumitomo Seika Chemical Co., Ltd.) [Water-soluble polymer having a nonionic hydroxyl group]
[Resin film (base material)]
Polyimide film 1: Aromatic polyimide film with a thickness of 25 μm (“FG-100” manufactured by PI Advanced Materials)

2. 2. Production and evaluation of dispersion [Example 1-1]
F particles 1, varnish 1, surfactant 1, and water were put into the pot, and zirconia balls were put into the pot. Then, the pot was rolled at 150 rpm for 1 hour, amine 1 was added, and F particles 1 (60 parts by mass), PAI 1 (0.6 parts by mass), surfactant 1 (3 parts by mass) and water (46 parts by mass) were added. A dispersion 1 containing (4 parts by mass) was obtained. The viscosity of the obtained dispersion liquid 1 was 1000 mPa · s, and the pH was 8.0.
Even when the dispersion liquid 1 was stored at 25 ° C. for a long period of time, no agglomerates were visually recognized and the dispersion liquid 1 was excellent in dispersibility.

[Example 1-2]
F particles 1, varnish 1, surfactant 1 and water were added to the pot and mixed to prepare a composition. This composition is kneaded in a planetary mixer and then taken out, and F particles 1 (60 parts by mass), PAI 1 (0.6 parts by mass), surfactant 1 (3 parts by mass) and water (20 parts by mass) are taken out. 1 was obtained.
Water was added to the kneaded powder 1 in a plurality of times, and the mixture was stirred while defoaming at 2000 rpm with a rotating revolution stirrer. Further, water is added in a plurality of times while stirring, and amine 1 is added to F particles 1 (60 parts by mass), PAI 1 (0.6 parts by mass), surfactant 1 (3 parts by mass) and. A dispersion 2 containing water (46.4 parts by mass) was obtained. The viscosity of the obtained dispersion liquid 2 was 800 mPa · s, and the pH was 8.0.

[Example 1-3] to [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 added to the pot and mixed to prepare a composition. This composition is kneaded in a planetary mixer and then taken out, and F particles 1 (50 parts by mass), PAI (0.6 parts by mass), surfactant 1 (3 parts by mass) and water (20 parts by mass) are taken out. 7 was obtained.
The F dispersion liquid 1 was added to the kneaded powder 7, and water was further added in a plurality of times, and the mixture was stirred while defoaming at 2000 rpm with a rotation / revolution stirrer. Further, water is added in a plurality of times while stirring, and amine 1 is added to F particles 1 (50 parts by mass), F particles 3 (10 parts by mass), PAI 1 (0.6 parts by mass), and an interface. A dispersion 7 containing activator 1 (3 parts by mass) and water (46.4 parts by mass) was obtained. The viscosity of the obtained dispersion 7 was 700 mPa · s, and the pH was 8.0.

[Example 1-8]
F particles 1, varnish 1, surfactant 1, polysaccharide 1 and water were added to the pot and mixed to prepare a composition. This composition is kneaded in a planetary mixer and then taken out, and F particles 1 (50 parts by mass), PAI (0.6 parts by mass), surfactant 1 (3 parts by mass), and polysaccharide 1 (0. A kneaded powder 8 containing 3 parts by mass) and water (20 parts by mass) was obtained.
The F dispersion liquid 1 was added to the kneaded powder 8, and water was further added in a plurality of times, and the mixture was stirred while defoaming at 2000 rpm with a rotating revolution stirrer. Further, water is added in a plurality of times while stirring, and amine 1 is added to F particles 1 (50 parts by mass), F particles 3 (10 parts by mass), PAI 1 (0.6 parts by mass), and an interface. A dispersion 8 containing an activator 1 (3 parts by mass), a polysaccharide 1 (0.3 parts by mass) and water (46.1 parts by mass) was obtained. The viscosity of the obtained dispersion liquid 8 was 3000 mPa · s, and the pH was 8.0.

3. 3. Manufacture and evaluation of laminate [Example 2-1]
By a roll-to-roll process, the dispersion liquid 1 obtained according to Example 1-1 is applied to one surface of the polyimide film 1 by a small-diameter gravure reverse method, and passed through a ventilation drying furnace (fired temperature 150 ° C.) in 3 minutes. The water was removed to form a dry film. Further, the dispersion liquid 1 was similarly applied to the other surface of the polyimide film 1 and dried to form a dry film.
Next, the polyimide film 1 having the dry film formed on both sides is passed through a far-infrared furnace (a furnace temperature of 300 ° C. near the inlet and outlet of the furnace, a furnace temperature of 360 ° C. near the center) in 5 minutes, and the F particles 1 are passed. Was melt-fired.
As a result, a polymer layer containing the melt-fired product of F particles 1 and PAI1 is formed on both sides of the polyimide film 1, and the polymer layer, the polyimide film layer, and the polymer layer are directly formed in this order (multilayer film 1). Was obtained by a roll-to-roll process. The thickness of the polymer layer in the multilayer film 1 was 25 μm.

[Example 2-2] to [Example 2-8]
Multilayer films 2 to 7 were obtained in the same manner as in Example 2-1 except that the dispersion liquids 2 to 8 were used instead of the dispersion liquid 1.
The porosity of the polymer layer of each multilayer film was smaller 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 was the densest.

4. Evaluation 4-1. Evaluation of Dispersion Layer Ratio of Dispersion Liquid Each dispersion liquid (18 mL) was placed in a screw tube (internal volume: 30 mL) and allowed to stand at 25 ° C. for 14 days. The dispersion layer ratio was calculated from the height of the entire dispersion liquid in the screw tube and the height of the sedimentation layer (dispersion layer) after standing still 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.
X: The dispersed layer ratio is less than 60%.

4-2. Fluctuation range of thixotropy of dispersions Each dispersion was stored in a container at 25 ° C. for 30 days, the fluctuation range of thixotropy before and after storage was measured, and the thixotropy stability was evaluated according to the following criteria.
[Evaluation criteria]
〇: Thixotropy fluctuation range (absolute value) is less than 1 Δ: Thixotropy fluctuation range (absolute value) is 1 or more and 3 or less ×: Thixotropy fluctuation range (absolute value) is 3 Is super

4-3. Evaluation of Surface Smoothness of Multilayer Films 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 A rectangular (length 100 mm, width 10 mm) test piece was cut out from each multilayer film, and a position of 50 mm from one end in the length direction of the test piece was fixed, and a tensile speed of 50 mm / min. The polymer layer and the polyimide film layer were peeled off from one end in the length direction at 90 ° to the test piece. The maximum load applied at that time was taken as the peel strength, and the interlayer adhesion was evaluated according to the following criteria.
[Evaluation criteria]
〇: 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.
X: The peel strength is less than 10 N / cm.
The results of each evaluation are summarized in Table 2 below.

As a result of measuring the dielectric loss tangent of each multilayer film by the SPDR (split post dielectric resonance) method (measurement frequency: 10 GHz), the dielectric loss tangent of the multilayer films 7 and 8 is the lowest, and both multilayer films are electric. It was superior to the characteristics. In addition, the thickness of the polymer layer having surface smoothness and interlayer adhesion that can be formed in a single laminating body manufacturing process was the largest when the dispersion liquid 8 was used.

The aqueous dispersion of the present invention has excellent dispersion stability and can be easily processed into films, fiber reinforced films, prepregs, and metal laminated plates (metal foils with resin). The obtained processed article can be used as a material for antenna parts, printed circuit boards, aircraft parts, automobile parts, sports equipment, food industry supplies, sliding bearings and the like. Further, since the laminate of the present invention is excellent in heat resistance and releasability, a carrier film for forming a ceramic green sheet, a carrier film for forming a secondary battery electrode film, a carrier film for forming a solid polymer electrolyte film, and a solid are used. It can also be used as a carrier film for forming a catalyst for a polymer electrolyte membrane.

Claims

An aqueous dispersion containing particles of a tetrafluoroethylene polymer, an aromatic imide resin having an acid value of 20 to 100 mg / KOH, and water, and having a pH of 5 to 10.
The aqueous dispersion according to claim 1, wherein the tetrafluoroethylene polymer is a tetrafluoroethylene polymer having an oxygen-containing polar group containing a unit based on perfluoro (alkyl vinyl ether).
The aqueous dispersion according to claim 1 or 2, wherein the tetrafluoroethylene-based polymer particles include non-heat-meltable tetrafluoroethylene-based polymer particles and heat-meltable tetrafluoroethylene-based polymer particles. ..
The aqueous dispersion according to any one of claims 1 to 3, wherein the aromatic imide resin is a precursor of a water-soluble aromatic polyamide-imide or a precursor of a 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, further comprising at least one nonionic polymer selected from the group consisting of a polyvinyl alcohol-based polymer, a polyvinylpyrrolidone-based polymer, and a polysaccharide.
The aqueous dispersion according to any one of claims 1 to 7, which contains amine or ammonia.
The aqueous solution 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 particles of the tetrafluoroethylene polymer is in the range of 0.001 to 0.1. Dispersion solution.
The one 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 with respect to the total mass of the aqueous dispersion. 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 for forming a polymer layer containing a tetrafluoroethylene polymer by applying it to at least one surface of a resin film and heating it.
The aqueous dispersion according to any one of claims 1 to 12, wherein the resin constituting the resin film is a polyimide resin.
A composition containing the tetrafluoroethylene polymer particles, the aromatic imide resin, and water is kneaded to obtain a kneaded product, and the kneaded product and water are mixed to obtain the aqueous dispersion. The method for producing an aqueous dispersion according to any one of claims 1 to 13.
Consists of the resin film, wherein the aqueous dispersion according to any one of claims 1 to 13 is applied to both surfaces of the resin film and heated to form the polymer layer containing a tetrafluoroethylene polymer. A laminate having the polymer layer on both sides of the base material layer to be formed.