KR20230126703A - Aqueous dispersion and its preparation method - Google Patents

Abstract

(Problem) A molded article with excellent dispersion stability, excellent physical properties such as low dielectric loss tangent and low transmission loss, flexibility such as bending resistance, UV absorption, and excellent adhesion and adhesion to resin films such as polyimide films. Provided is an aqueous dispersion comprising particles of a tetrafluoroethylene-based polymer, capable of forming a.
(Means for solution) An aqueous dispersion liquid containing tetrafluoroethylene-based polymer particles, an aromatic imide-based resin having an acid value of 20 to 100 mg/KOH, and water, and having a pH of 5 to 10.

Description

Aqueous dispersion and its preparation method

The present invention relates to an aqueous dispersion comprising particles of a tetrafluoroethylene-based polymer and a specific aromatic imide-based resin, and a method for preparing 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 Document 1). As a coating agent used to impart the above physical properties to the surface of a substrate, a dispersion containing particles of a tetrafluoroethylene-based polymer is known.

Particularly, in recent years, a dispersion containing particles of a tetrafluoroethylene-based polymer has attracted attention as a material having excellent electrical properties such as a low dielectric constant and a low dielectric loss tangent, which forms a dielectric layer of a printed circuit board corresponding to a high frequency band.

From the viewpoint of handleability, it is preferable to make the dispersion liquid into an aqueous system. Patent Literature 2 discloses a laminate formed by applying an aqueous dispersion of a fluorine-based resin to one side or both sides of a resin film and heating it. Patent Literature 3 discloses a composition containing a water-based polyimide precursor, a fluororesin, and water, in which they 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, compared with non-aqueous dispersions, aqueous dispersions of tetrafluoroethylene-based polymers generally have a poorer dispersion state. Therefore, in the coating and firing of the substrate, the packing of the particles of the tetrafluoroethylene-based polymer becomes loose, and a problem is likely to occur in the compactness of the polymer layer 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 tend to occur in the polymer layer. According to the examination of the present inventors, it was found that this tendency becomes remarkable when the aqueous dispersion of the prior art literature is used.

As a result of intensive studies, the inventors of the present invention have found that a dispersion containing particles of a tetrafluoroethylene-based polymer, a specific aromatic imide-based resin, and water and having a pH within a specific range has excellent dispersion stability. In addition, it was found that molded articles obtained from such a dispersion are dense, excellent in low dielectric loss tangent, low linear expansion coefficient, etc., flexibility such as bending resistance, UV absorption, and improved adhesion and adhesion to plastic films such as polyimide films. did

An object of the present invention is to provide an aqueous dispersion in which a molded article obtained has excellent dispersion stability, flexibility such as bending resistance, UV absorption, and adhesion and adhesion to a resin film such as a polyimide film.

The present invention has the following aspects.

<1> An aqueous dispersion containing tetrafluoroethylene-based polymer particles, an aromatic imide-based 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 according to <1>, wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having an oxygen-containing polar group containing perfluoro(alkylvinyl ether)-based units.

<3> The method of <1> or <2>, wherein the particles of the tetrafluoroethylene-based polymer include particles of a non-heat-melting tetrafluoroethylene-based polymer and particles of a heat-melting tetrafluoroethylene-based polymer aqueous dispersion.

<4> The aqueous dispersion according to any one of <1> to <3>, wherein the aromatic imide-based resin is a water-soluble aromatic polyamideimide precursor or a water-soluble aromatic polyimide precursor.

<5> The aqueous dispersion liquid according to any one of <1> to <4>, further containing an inorganic filler.

<6> The aqueous dispersion liquid according to any one of <1> to <5>, further containing a nonionic surfactant.

<7> The aqueous dispersion liquid according to any one of <1> to <6>, which further contains at least one nonionic polymer selected from the group consisting of polyvinyl alcohol-based polymers, polyvinylpyrrolidone-based polymers, and polysaccharides.

<8> The aqueous dispersion liquid according to any one of <1> to <7>, containing amine or ammonia.

<9> The aqueous dispersion according to any one of <1> to <8>, wherein a ratio of the mass of the aromatic imide-based resin to the mass of the tetrafluoroethylene-based polymer particles is in the range of 0.001 to 0.1.

<10> The aqueous dispersion according to any one of <1> to <9>, wherein the total content of the particles and the aromatic imide-based resin in the aqueous dispersion is 20% by mass or more with respect to the total mass of the aqueous dispersion.

<11> The aqueous dispersion liquid according to any one of <1> to <10>, wherein the viscosity is 50 to 3000 mPa·s.

<12> The aqueous dispersion according to any one of <1> to <11>, which is used for forming a polymer layer containing a tetrafluoroethylene-based polymer by applying and heating to at least one surface of a resin film.

<13> The aqueous dispersion according to any one of <1> to <12>, wherein the resin constituting the resin film is a polyimide resin.

<14> kneading the particles of the tetrafluoroethylene-based polymer, the aromatic imide-based resin, and a composition containing water to obtain a kneaded product, and mixing the kneaded product and water to obtain the aqueous dispersion, <1 A method for producing an aqueous dispersion liquid according to any of > to <13>.

<15> A substrate composed of the resin film in which the aqueous dispersion of any one of <1> to <13> is applied to both surfaces of a resin film and heated to form the polymer layer containing a tetrafluoroethylene-based polymer. A laminate having the polymer layer on both sides of the layer.

According to the present invention, it is possible to provide an aqueous dispersion of a tetrafluoroethylene-based 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 electrical properties such as low dielectric loss tangent and low transmission loss, flexibility such as bending resistance, UV absorption, and adhesion and adhesion to resin films such as polyimide films. Excellent moldings can be formed. Therefore, the aqueous dispersion of the present invention is useful, for example, as a constituent material of a printed circuit board.

The terms below have the following meanings.

The "average particle diameter (D50)" is the volume-based cumulative 50% diameter of the object (particles and filler) determined by the laser diffraction/scattering method. That is, the particle size distribution is measured by the laser diffraction/scattering method, a cumulative curve is obtained with the total volume of the group of objects (particles and fillers) as 100%, and the particle diameter at the point where the cumulative volume is 50% on the cumulative curve am.

D50 of the target object (particles and filler) is obtained by dispersing the target object (particles and filler) in water and using a laser diffraction/scattering type particle size distribution analyzer (LA-920 measuring instrument manufactured by Horiba Manufacturing Co., Ltd.). It is analyzed and obtained by

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

"Viscosity" is obtained by measuring the object (dispersion and kneaded product) at 25°C and under the condition that the number of revolutions is 30 rpm using a B-type viscometer. The measurement is repeated three times, and the average value of the measured values for the three times is taken.

The "tick ratio" is a value calculated by dividing the viscosity η ₁ of an object (dispersion or kneaded material) measured under the condition that the rotation speed is 30 rpm by the viscosity η ₂ measured under the condition that the rotation speed is 60 rpm. The measurement of each viscosity is repeated 3 times, and the average value of the measurements for 3 times is taken.

The "HLB value of the polyoxyalkylene-modified polydimethylsiloxane" is a value calculated by the Griffin formula, and is obtained by multiplying the value obtained by dividing the molecular weight of the polyoxyalkylene moiety in the molecule by the molecular weight of the organopolysiloxane.

"Static surface tension" is obtained by the Wilhelmy method using an automatic surface tension meter CBVP-Z type (manufactured by Kyowa Interface Science Co., Ltd.) and using 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 in the maximum foaming method, and is a polyoxyalkylene-modified surface tension. The dynamic surface tension of an aqueous solution containing polydimethylsiloxane at a rate of 0.1% by mass was measured by the maximum pressure method by immersing a sensor of a dynamic surface tension meter Theta t60 manufactured by Eco Seiki Co., Ltd. in an environment at a temperature of 25 ° C. in the aqueous solution. is the value being measured. The measurement is performed by setting the bubble generation period of the aqueous solution to 6 Hz.

A "unit" in a polymer means 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 treating a polymer. Hereinafter, the unit based on the monomer a is simply referred to as "monomer a unit".

The aqueous dispersion of the present invention (hereinafter also referred to as "this dispersion") contains particles of a tetrafluoroethylene-based polymer (hereinafter also referred to as "F polymer") (hereinafter also referred to as "F particles"). ), 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 is excellent in dispersion stability. In addition, the molded product (fired product) formed from this dispersion has excellent physical properties based on the tetrafluoroethylene-based polymer, such as electrical properties, and excellent surface smoothness, as well as flexibility such as bending resistance, UV absorption, and poly It is also excellent in adhesiveness and adhesiveness with resin films, such as a mid film.

The reason why the dispersion stability of this dispersion is improved is not necessarily clear, but it is estimated, for example, as follows.

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 dispersing agent for F particles in the present dispersion liquid, but also acts as a viscosity modifier for the present dispersion liquid. It is thought that the dispersion stability of is improved. Moreover, the pH of this dispersion liquid in a specific range not only enhances this action, but also enhances the reactivity of the imide-based resin P when forming a molded product by heating this dispersion liquid. As a result, it is considered that the interaction between the imide-based resin P and the F polymer or the base material is increased, and the flexibility and adhesiveness/adhesion (binder ability) of the resulting molded product are improved. As a result, it is considered that this dispersion is excellent in dispersion stability, and molded articles having excellent electrical properties, bending resistance, UV absorption, etc., can be formed from this dispersion in a continuous production process such as roll-to-roll.

Polymer F in this dispersion is a polymer containing tetrafluoroethylene (TFE)-based units (TFE units). 1 type may be used for F polymer, and 2 or more types may be used. The F polymer may be either heat-meltable or non-heat-meltable, but at least one of the F polymers is preferably heat-meltable. In such a case, a molded article formed from the present dispersion tends to be excellent in flexibility and adhesiveness and adhesion to a resin film such as a polyimide film. In addition, thermal meltability means a polymer having melt flowability at a temperature at which the melt flow rate is 0.1 to 1000 g/10 minutes at a temperature 20° C. or more higher than the melting temperature of the polymer under the condition of a load of 49 N.

When the F polymer is heat meltable, the melting temperature is preferably 200 to 320°C, more preferably 260 to 320°C. In such a case, molded articles formed from the present dispersion tend to have excellent heat resistance.

It is preferable that it is 70 mass % or more, and, as for the fluorine atom content in polymer F, it is more preferable that it is 70-76 mass %. This dispersion is particularly likely to improve the dispersibility in water of the particles of the F polymer having a high fluorine atom content due to the mechanism of action described above.

75-125 degreeC is preferable, and, as for the glass transition point of F polymer, 80-100 degreeC is more preferable.

As the F polymer, polytetrafluoroethylene (PTFE), a polymer comprising TFE units and units based on ethylene (ETFE), units based on TFE units and perfluoro (alkylvinyl ether) (PAVE) (PAVE units) (PFA), polymers (FEP) containing units based on TFE units and hexafluoropropene (HFP). Each of ETFE, PFA, and FEP may further contain another unit. As PAVE, CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ and CF ₂ =CFOCF ₂ CF ₂ CF ₃ (PPVE) are preferable, and PPVE is more preferable.

Polymer F is preferably PFA or FEP, and more preferably PFA.

At least one type of polymer F preferably has an oxygen-containing polar group. In this case, since affinity between polymer F, imide-based resin P, and water is improved, the present dispersion tends to have excellent dispersion stability. In this case, it is considered that the polymer F reacts with the imide-based resin P to form a crosslink during firing of the dispersion, and as a result, the fired product (such as a polymer layer) obtained from the dispersion has electrical properties, surface smoothness, It is considered that physical properties such as adhesion and adhesion to resin films such as polyimide films are further excellent.

The oxygen-containing polar group may be contained in a unit in the F polymer or may be contained in a terminal group of the main chain of the F polymer. Examples of the latter aspect include 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, and an F polymer having an oxygen-containing polar group obtained by subjecting the F polymer to plasma treatment or ionizing radiation treatment. The oxygen-containing polar group is preferably a hydroxyl group-containing group, a carbonyl group-containing group, and a phosphono group-containing group, from the viewpoint of the dispersion stability of the present dispersion, a hydroxyl group-containing group and a carbonyl group-containing group are more preferable, and a carbonyl group-containing group is still more preferable.

The hydroxyl group-containing group is preferably a group containing an alcoholic hydroxyl group, and more preferably -CF ₂ CH ₂ OH, -C(CF ₃ ) ₂ OH, and a 1,2-glycol group (-CH(OH)CH ₂ OH).

The carbonyl group-containing group is a group containing a carbonyl group (>C(O)), and is a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC(O)NH ₂ ), an acid anhydride residue (-C( O)OC(O)-), imide residues (-C(O)NHC(O)-, etc.) and carbonate groups (-OC(O)O-) are preferred, and acid anhydride residues are more preferred.

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 to 1500 per 1×10 ⁶ carbon atoms of the main chain. more preferable In addition, the number of carbonyl group-containing groups in the F polymer can be quantified by the method described in the composition of the polymer or International Publication No. 2020/145133.

The F polymer is preferably a polymer having an oxygen-containing polar group, including a TFE unit and a PAVE unit, and more preferably a polymer containing a unit based on a monomer having a TFE unit, a PAVE unit, and an oxygen-containing polar group, It is more preferable that it is a polymer containing 90-99 mol%, 0.5-9.97 mol%, and 0.01-3 mol% of these units in this order with respect to all units.

The monomer having an oxygen-containing polar group is preferably itaconic acid anhydride, citraconic acid anhydride or 5-norbornene-2,3-dicarboxylic acid anhydride (hereinafter also referred to as "NAH").

As a specific example of such a polymer, the polymer described in International Publication No. 2018/16644 is mentioned.

In these F polymers, the particles are not only excellent in dispersion stability, but also tend to be more densely and homogeneously distributed in molded products (such as polymer layers) obtained from this dispersion. In addition, it is easy to form microspherulites in the molded product, and the adhesion to other components is easy to increase. As a result, molded products excellent in various physical properties such as electrical properties are more easily obtained.

Examples of the non-heat-melting polymer F include non-heat-melting PTFE.

As for the number average molecular weight of non-heat-melting PTFE, 1 million - 100 million are preferable. In addition, the number average molecular weight of non-heat-meltable PTFE is a value calculated based on the following formula (1).

Mn = 2.1 × 10 ¹⁰ × ΔHc ^-5.16 ... (1)

In Formula (1), Mn represents the number average molecular weight of non-heat-meltable PTFE, and ΔHc represents the heat of crystallization (cal/g) of non-thermally-meltable PTFE measured by differential scanning calorimetry, respectively.

When the number average molecular weight is within this range, the F polymer is less likely to fibrillate and the present dispersion tends to have excellent dispersion stability.

In this dispersion, the D50 of the 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 still 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, and still more preferably 2 μm or more. At D50 within this range, the fluidity and dispersibility of the 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, and 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, and more preferably 0.35 g/m 2 or less.

Moreover, the specific surface area of the F particles is preferably 1 to 8 m 2 /g, and more preferably 1 to 3 m 2 /g.

1 type may be used for F particle|grains, and 2 or more types may be used. When using two types of F particles, it is preferable to include particles of a non-heat-meltable F polymer and particles of a heat-meltable F polymer, and non-heat-meltable PTFE (preferably, the number average molecular weight described above is 1,000,000 to 1,000,000). 100 million PTFE) particles and particles of F polymer (preferably a polymer having an oxygen-containing polar group containing the above-described TFE units and PAVE units) having a melting temperature of 200 to 320 ° C. .

In this case, as for the ratio of the contained masses of the two particles, the contained mass of the former particles may be greater than the contained mass of the latter particles, and the contained mass of the former particles may be less than the contained mass of the latter particles.

And it is more preferable that the contained mass of the former particle|grains is larger than the contained mass of the latter particle|grains.

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, and more preferably 15% by mass or less. Moreover, as for the ratio in this case, 0.1 mass % or more is preferable and 1 mass % or more is more preferable.

Such a present dispersion liquid tends to be excellent in dispersion stability, handleability and long-term storage stability, and it is easy to form an adhesive molded product based on PTFE and having excellent physical properties.

In addition, when the content mass of the former particles is smaller than the content mass of the latter particles, it is preferable from the viewpoint of facilitating the formation of molded products having excellent adhesion 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, and more preferably 25% by mass or less. Moreover, 5 mass % or more is preferable and, as for the said ratio, 10 mass % or more is more preferable.

In the case of using non-heat-melting polymer F particles and F-polymer particles having a melting temperature of 200 to 320 ° C., the D50 of the non-heat-melting PTFE particles is 0.1 to 1 μm and the melting temperature is 200 to 320 ° C. F The D50 of the polymer particles is 0.1 to 1 μm, the D50 of the non-heat-meltable PTFE particles is 0.1 to 1 μm, and the melting temperature is 200 to 320 ° C. The D50 of the polymer particles is 1 to 4 μm. desirable.

The F particles may contain a resin or an inorganic filler other than the F polymer, but it is preferable to have the F polymer as a main component. 80 mass % or more is preferable and, as for content of the F polymer in F particle|grains, 100 mass % is more preferable.

Examples of the resin include heat-resistant resins such as aromatic polyester, polyamideimide, (thermoplastic) polyimide, polyphenylene ether, polyphenylene oxide, and maleimide. Examples of the inorganic filler include silicon oxide (silica), metal oxides (beryllium oxide, cerium oxide, alumina, soda alumina, magnesium oxide, zinc oxide, titanium oxide, etc.), boron nitride, and magnesium metasilicate (steatite). . At least a part of the surface of the inorganic filler may be surface-treated.

The F particles containing a resin other than the F polymer or an inorganic filler have a core-shell structure having the F polymer as a core and a resin or inorganic filler other than the F polymer as a shell, or having the F polymer as a shell and the F polymer You may have a core-shell structure in which other resins or inorganic fillers are included in the core. Such F particles are obtained, for example, by bonding (collision, aggregation, etc.) particles of the F polymer with particles of a resin or inorganic filler other than the F polymer.

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

As the imide-based resin P, an aromatic polyimide, an aromatic polyimide precursor (polyamic acid or a salt thereof), an aromatic polyamideimide, an aromatic polyamideimide precursor, a modified aromatic polyimide having a polar functional group such as a carboxylic acid group, or a modified aromatic polyi A mid precursor, a modified aromatic polyamideimide, a modified aromatic polyamideimide precursor, an aromatic polyetherimide, or an aromatic polyetherimide precursor.

Among them, an aromatic polyimide or a precursor thereof (polyamic acid or a salt thereof), an aromatic polyamideimide or a precursor thereof is preferable, a water-soluble aromatic polyimide precursor or a water-soluble aromatic polyamideimide precursor is more preferable, and a water-soluble aromatic Polyamideimide precursors are more preferred.

Examples of the water-soluble aromatic polyimide precursor include polyamic acid obtained by polymerizing tetracarboxylic dianhydride and diamine in a solvent, and polyamic acid salt obtained by reacting the polyamic acid with aqueous ammonia or organic amine. The aqueous solution of a polyamic acid can be prepared by dissolving a polyamic acid salt in water.

As tetracarboxylic dianhydride, pyromellitic acid anhydride and biphenyl tetracarboxylic acid anhydride are mentioned, for example. As diamine, N,N'-diaminodiphenyl ether and p-diaminobenzene are mentioned, for example. Examples of the solvent include N-methylpyrrolidone and N,N-dimethylformamide.

Examples of organic amines include primary amines such as methylamine, ethylamine, n-propylamine, 2-ethanolamine, and 2-amino-2-methyl-1-propanol; secondary amines such as dimethylamine, 2-(methylamino)ethanol, and 2-(ethylamino)ethanol; tertiary amines such as 2-dimethylaminoethanol, 2-diethylaminoethanol, and 1-dimethylamino-2-propanol; and quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide.

Examples of water-soluble aromatic polyamideimide resins or precursors thereof include polyamideimide resins or precursors thereof obtained by reacting diisocyanate and/or diamine with tribasic acid anhydride (or tribasic acid chloride) as an acid component.

Examples of the diisocyanate include 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, and 3,3'-diphenylmethane diisocyanate. Isocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, p-phenylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, tolylene diisocyanate, and isophorone diisocyanate. can These diisocyanates may be used individually by 1 type, and may be used in combination of 2 or more types.

Moreover, you may use the block type isocyanate which stabilized the isocyanate group as a diisocyanate from a viewpoint of improving the stability of aromatic polyamide-imide resin with a blocking agent. Alcohol, phenol, and an oxime etc. are mentioned as a blocking agent.

As diamine, for example, 3,3'-dimethylbiphenyl-4,4'-diamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'- diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, xylylenediamine, phenylenediamine, and isophoronediamine. These diamines may be used individually by 1 type, and may be used in combination of 2 or more types.

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

When producing an aromatic polyamideimide resin, dicarboxylic acid, tetracarboxylic dianhydride, etc., as an acid component in addition to the above tribasic acid anhydride (or tribasic acid chloride) are not used to impair the properties of the polyamideimide resin. It may be used within the range of

As dicarboxylic acid, terephthalic acid, isophthalic acid, adipic acid, and sebacic acid are mentioned, for example. As tetracarboxylic dianhydride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, and biphenyl tetracarboxylic dianhydride are mentioned, for example. These may be used individually by 1 type, and may be used in combination of 2 or more types.

The total amount of carboxylic acids other than tribasic acid (dicarboxylic acid and tetracarboxylic acid) is preferably in the range of 0 to 30 mol% of all carboxylic acids from the viewpoint of maintaining the characteristics of the polyamideimide resin. .

The use 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 dianhydride used as necessary) is the polyamideimide produced From the viewpoint of the molecular weight and degree of crosslinking of the resin, the diisocyanate compound and/or the diamine compound is preferably 0.8 to 1.1 mole, more preferably 0.95 to 1.08 mole, and 1.0 to 1.08 mole, relative to 1.0 mole of the total amount of the acid component. it is more preferable

A water-soluble aromatic polyamideimide resin or a precursor thereof is obtained by copolymerizing the diisocyanate and/or diamine and the acid component in a polar solvent. As the polar solvent, N-methyl-2-pyrrolidone, N-formylmorpholine, N-acetylmorpholine, N,N'-dimethylethyleneurea, N,N-dimethylacetamide, N,N-dimethyl Formamide, (gamma)-butyrolactone, etc. are mentioned. From the viewpoint of carrying out the amidimidation reaction at a high temperature in a short time, a solvent having a high boiling point is preferable, and from the viewpoint of solubility, N-methyl-2-pyrrolidone is generally used. From the viewpoints of ease of work environment and safety management, N-formylmorpholine is also preferable.

The amount of the polar solvent used is usually 50 to 500 parts by mass based on 100 parts by mass of the total amount of the diisocyanate or diamine and the acid component, from the viewpoint of solubility of the obtained aromatic polyamideimide resin or its precursor.

The polymerization temperature is usually in the range of 80 to 180°C, and it is preferably carried out in an atmosphere such as nitrogen in order to reduce the influence of moisture in the air.

The water-soluble aromatic polyamideimide resin or its precursor is, for example, (1) a method of reacting an acid component and a diisocyanate component and/or a diamine component at once; (2) After reacting an acid component with an excessive amount of a diisocyanate component and/or a diamine component to synthesize an amideimide oligomer having an isocyanate group or an amino group at the terminal, an acid component is added to obtain a terminal isocyanate group and/or Method to make it react with an amino group; (3) After reacting an excessive amount of the acid component with a diisocyanate component and/or a diamine component to synthesize an amideimide oligomer having an acid or acid anhydride group at the terminal, a diisocyanate component and/or a diamine component are added to form a terminal a method of reacting with an acid or acid anhydride group; can be manufactured with

The number average molecular weight (Mn) of the water-soluble aromatic polyamideimide resin or its precursor is preferably 5000 or more, more preferably 10000 or more, still more preferably 15000 or more. On the other hand, Mn is preferably 50000 or less, more preferably 30000 or less, and still more preferably 25000 or less. When Mn is within this range, mechanical properties such as solubility of the aromatic polyamideimide resin or its precursor in water and bending resistance of molded articles obtained from the present dispersion can be secured.

In addition, the Mn of the aromatic polyamideimide resin or its precursor is appropriately sampled in the reaction solution during polymerization and measured using a standard polystyrene calibration curve by gel permeation chromatography (GPC) to obtain the target Mn. It can be managed within the above range by performing polymerization until

Examples of the aromatic polyetherimide include amorphous polymers 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 of phenylenediamine is preferred. As a commercial item of aromatic polyetherimide, "Ultem 1000F3SP" (made by SABIC) is mentioned, for example.

The acid value of the imide-based resin P is 20 to 100 mg/KOH. In this dispersion liquid, the functions are balanced by adjusting the acid value of imide-based resin P to such a range. 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 at the time of forming a molded product from the dispersion is improved to increase the physical properties of the molded product, but the dispersing action is lowered, thereby improving the dispersion stability of the dispersion. lower it down In addition, when the acid value of the imide-based resin P is more than 100 mg/KOH, the dispersing action of the imide-based resin P in the dispersion liquid is increased, whereas the reaction rate of the imide-based resin P when forming a molded product from the dispersion liquid is lowered, and the molded product degrade the physical properties.

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 water-soluble, the imide-based resin P tends to interact easily with F particles and water, and is formed from the present dispersion. The molded article tends to have excellent adhesion to the substrate. In addition, when the acid value is 100 mgKOH/g or less, the storage stability of the present dispersion tends to be improved.

Moreover, from such a viewpoint, it is preferable that the acid value of imide-type resin P is 35-70 mgKOH/g. In addition, when imide-type resin P has an acid anhydride group, let the acid value at the time of ring-opening an acid anhydride group be the acid value of imide-type resin P.

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

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

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

The total content of F particles and imide-based resin P in the present dispersion is preferably 20% by mass or more with respect to the total mass of the present dispersion. As for the said total content, it is more preferable that it is 30 mass % or more, and it is still more preferable that it is 40 mass % or more. It is preferable that the said total content is 80 mass % or less. 30-80 mass % is mentioned as a specific example of the preferable range of the said total content.

In this case, moldings such as coating films can be formed with high uniformity from this dispersion, and the physical properties of the polymer F and the physical properties of the imide-based resin P are highly likely to be expressed. That is, even if the content of the polymer component is in such a high range, the dispersion liquid has excellent dispersion stability and can improve the physical properties of the molded product due to the mechanism of action described above.

Further, the ratio of the mass of the imide-based resin P to the mass of the F particles in the dispersion is preferably 0.001 or more, more preferably 0.005 or more, still more preferably 0.01 or more. The ratio is preferably 0.1 or less, more preferably 0.09 or less, and still more preferably 0.05 or less. As a specific example of the preferable range of the said ratio, 0.001-0.1 is mentioned.

When the ratio is in such a low range, the dispersion stability of the F particles is improved, and the physical properties of molded articles obtained from the present dispersion are particularly likely to be improved. Although the reason for this is not necessarily clear, in this dispersion in which the acid value of the imide-based resin P and the pH of the aqueous dispersion are within a predetermined range, and the imide-based resin P is a small component with respect to the F particles, the imide-based resin P is, It is thought that this is because the dispersant of the low hydrophilic F particles also functions highly as a binder, in other words, the imide-based resin P adheres to the surface of the F particles and promotes precise firing of the F particles during formation of molded products. .

The content of water in the present dispersion is preferably 40% by mass or more, and more preferably 50% by mass or more. 90 mass % or less is preferable and, as for content of water, 80 mass % or less is more preferable.

In this range, the dispersion stability of the present dispersion liquid is more likely to be improved by the mechanism of action described above.

This dispersion liquid may further contain a water-soluble dispersion medium other than water as a dispersion medium. As such a water-soluble dispersion medium, water-soluble compounds classified as polar under atmospheric pressure and liquid at 25° C. are preferable, such as N,N-dimethylformamide, N,N-dimethylacetamide, 3-methoxy-N, N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and N-methyl-2-pyrrolidone.

This dispersion may further contain a surfactant. When the present dispersion contains a surfactant, the surfactant is nonionic, the hydrophobic portion of the surfactant preferably has an acetylene group or a polysiloxane group, and the hydrophilic portion preferably has an oxyalkylene group or an alcoholic 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, acetylenic surfactant or silicone surfactant is more preferable. These surfactants may be used individually by 1 type, and may use 2 or more types together. The polyoxyalkylene alkyl ether stabilizes the long-term dispersibility of the F particles and improves the liquid properties such as the viscosity of the present dispersion, and the silicone surfactant improves the initial dispersibility of the F particles. It is preferable to use together an oxyalkylene alkyl ether and a silicone type surfactant.

When the present dispersion further contains a surfactant, the amount thereof is preferably from 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 more likely to be 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, from the viewpoint of being able to suppress the load on the environment, and It is preferable from the viewpoint of 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 a linear polymer. It is desirable to be

The weight average molecular weight of the modified polydimethylsiloxane is 3000 or less, preferably 2500 or less, and more preferably 2000 or less. It is preferable that it is 100 or more, and, as for a weight average molecular weight, it is more preferable that it is 500 or more.

3000 or less are preferable and, as for the number average molecular weight of modified polydimethylsiloxane, 1500 or less are more preferable. 100 or more are preferable and, as for a number average molecular weight, 500 or more are more preferable.

The degree of molecular weight dispersion of the modified polydimethylsiloxane is preferably less than 2.0, and more preferably 1.8 or less. The lower limit of the degree of molecular weight dispersion is preferably greater than 1.0.

The HLB value of the modified polydimethylsiloxane is 1 to 18, preferably 3 or more, more preferably 6 or more, still more preferably 10 or more, and particularly preferably 12 or more. It is preferable that it is 16 or less, and, as for an HLB value, it is more preferable that it is 15 or less.

The static surface tension of the modified polydimethylsiloxane is preferably 28 mN/m or less, and more preferably 26 mN/m or less. The static surface tension is preferably 15 mN/m or more, and more preferably 20 mN/m or more.

The dynamic surface tension of the modified polydimethylsiloxane is preferably 40 mN/m or less, and more preferably 35 mN/m or less. The dynamic surface tension is preferably 20 mN/m or more.

Modified polydimethylsiloxane may have a dimethylsiloxane unit (-(CH ₃ ) ₂ SiO _2/2 -) in the main chain, may have a dimethylsiloxane unit in the side chain, and may have dimethylsiloxane units in both the main chain and the side chain. You may have a siloxane unit.

The modified polydimethylsiloxane is a modified polydimethylsiloxane containing a dimethylsiloxane unit in the main chain and having an oxyalkylene group in the side chain, or a modified polydimethylsiloxane having a dimethylsiloxane unit in the main chain and having an oxyalkylene group at the terminal of the main chain. Modified polydimethylsiloxanes are preferred.

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

Since modified polydimethylsiloxane has a small weight average molecular weight and an HLB value within a predetermined range, it can also be said that its hydrophobicity and hydrophilicity are highly balanced. It is thought that such a modified polydimethylsiloxane tends to enhance interaction with the F particles, and as a result, the dispersion stability of the present dispersion is improved.

In addition, since modified dimethylsiloxane is excellent in thermal decomposability, it is easily decomposed when heating the present dispersion to form a fired product. As a result, the fired product tends to have a high degree of physical properties based on the F polymer.

Polyoxyalkylene alkyl ether, polyoxyethylene decyl ether, polyoxyethylene undecyl ether, polyoxyethylene dodecyl ether, polyoxyethylene tridecyl ether, polyoxyethylene tetradecyl ether, triethylene glycol monomethyl ether, polyethylene Glycol trimethyl nonyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, triethylene glycol monomethyl ether, Diethylene glycol monoethyl ether acetate and diethylene glycol monobutyl ether acetate are preferable, and polyoxyethylene decyl ether, polyoxyethylene undecyl ether, polyoxyethylene dodecyl ether, polyoxyethylene tridecyl ether, or polyoxyethylene It is more preferable that it is ethylene tetradecyl ether.

Polyoxyalkylene alkyl ether can be obtained as a commercial item, specifically, "Tergitol TMN-100X" (manufactured by Dow Chemical Co.); "Lutensol TO8", "Lutensol XL70", "Lutensol XL80", "Lutensol XL90", "Lutensol XP80", "Lutensol M5" (above, manufactured by BASF); "Leocol SC-90" (above, Lion Specialty Chemicals company make) is mentioned.

When this dispersion contains a surfactant, polyoxyalkylene alkyl ether can be obtained as a commercial item, and specifically, "Tergitol TMN-100X" (made by Dow Chemical Co.); "Lutensol TO8" is mentioned.

Further, when the present dispersion further contains a surfactant, the amount thereof is preferably 0.1% by mass or more, and more preferably 0.1% by mass or more, with respect to the total mass of the present dispersion. Moreover, as for the said quantity, 15 mass % or less is preferable.

This dispersion may further contain at least one nonionic polymer selected from the group consisting of polyvinyl alcohol-based polymers, polyvinylpyrrolidone-based polymers, and polysaccharides. It is highly preferable that these nonionic polymers are water-soluble polymers. In this case, due to the interaction between the water-soluble polymer and the imide-based resin P, not only the dispersion stability but also the rheological properties of the dispersion are improved, and the handling of the dispersion, such as film formability, is likely to be further improved. As a result, it is easier to form thick molded articles or molded articles of arbitrary shapes from the present dispersion. In particular, when the water-soluble polymer has a nonionic hydroxyl group, this tendency tends to become remarkable.

The polyvinyl alcohol-based polymer may be partially acetylated or partially acetalized polyvinyl alcohol.

Examples of polysaccharides include glycogens, amylopectins, dextrins, glucans, fructans, chitins, amyloses, agaroses, amylopectins, and celluloses. Examples of the cellulose include methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose.

The water-soluble nonionic polymer is preferably a nonionic polysaccharide, more preferably a nonionic cellulose, and more preferably hydroxymethyl cellulose, hydroxyethyl cellulose or hydroxypropyl cellulose.

Specific examples of such nonionic polysaccharides include "Sunrose (registered trademark)" series (manufactured by Nippon Paper Co., Ltd.), "Metrose (registered trademark)" series (manufactured by Shin-Etsu Chemical Co., Ltd.), "HEC CF Grade" ( manufactured by Sumitomo Chemical Co., Ltd.).

Moreover, when this dispersion liquid further contains a water-soluble nonionic polymer, the amount is preferably 0.01 mass % or more, and more preferably 0.1 mass % or more with respect to the total mass of this dispersion liquid. Moreover, as for the said quantity, less than 1 mass % is preferable. The ratio of the mass of the water-soluble nonionic polymer to the mass of the F particles in the present dispersion is preferably 0.001 or more, and more preferably 0.01 or more. Moreover, as for the said ratio, less than 0.1 is preferable.

As described above, due to the interaction between the water-soluble polymer and the imide-based resin P, the effect of improving the liquid properties and film-forming properties of the present dispersion is likely to be obtained due to the inclusion of a small amount of the water-soluble polymer. As a result, the residual amount of the water-soluble polymer in the molded article obtained from the present dispersion is reduced, and a molded article having better physical properties such as electrical properties is easily obtained from the present dispersion. In particular, when the water-soluble polymer has a nonionic hydroxyl group, this tendency is remarkable.

This dispersion liquid may further contain amine or ammonia. An amine or ammonia also has a role as a pH adjuster, and it is thought that it contributes also to the improvement of the dispersion stability and storage stability of this dispersion liquid. When the present dispersion further contains amine or ammonia, the amount may be such that the pH of the present dispersion is 5 to 10.

Examples of the amine include dimethylamine, diethylamine, diisopropylamine, diethanolamine, triethanolamine, trippropanolamine, 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 hydrogen carbonate, ammonium carbonate and ammonium acetate.

This dispersion may further contain a resin material other than polymer F and imide-based resin P from the viewpoint of improving the adhesion and low linear expansion properties of molded articles formed from this 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 resins, phenolic resins, liquid crystalline polyesters, liquid crystalline polyesteramides, polyolefin resins, modified polyphenylene ethers, polyfunctional cyanate ester resins, polyfunctional maleimide-cyanate ester resins, Functional maleimide, aromatic elastomers such as styrene elastomers, vinyl ester resins, urea resins, diallylphthalate resins, melamine resins, guanamine resins, melamine-urea cocondensation resins, polycarbonates, polyarylates, polysulfones, polyallylsulfones , aromatic polyamide, aromatic polyetheramide, polyphenylene sulfide, 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.

A preferable aspect of the resin material is an aromatic polymer. It is preferable that an aromatic polymer is polyphenylene ether or an aromatic elastomer (styrene elastomer etc.). In this case, not only the adhesiveness and low linear expansion properties of molded articles formed from the dispersion are further improved, but also the liquid properties (viscosity, tick ratio, etc.) of the dispersion are well balanced, so the handling thereof is likely to be improved.

Here, examples of the styrene elastomer include copolymers of styrene and conjugated dienes or (meth)acrylic acid esters (styrene-butadiene rubber, styrene-based core-shell copolymers, styrene-based block copolymers, etc.), and rubber and plastics A styrene elastomer having both properties and exhibiting flexibility by being plasticized by heating is preferred.

This dispersion may further contain an inorganic filler. In this case, molded products produced from the present dispersion tend to have excellent electrical properties and low linear expansion properties. Moreover, even if this dispersion liquid contains an inorganic filler, it is excellent in dispersion stability by the mechanism of action mentioned above, and it is easy to obtain a dense molded article from it. Therefore, from this dispersion containing the inorganic filler, it is easy to produce a molded product having a high degree of physical properties of the F polymer, the imide resin P, and the inorganic filler.

The inorganic filler is preferably a nitride filler or an inorganic oxide filler, boron nitride filler, aluminum nitride filler, beryllia filler (beryllium oxide filler), silicate filler (silica filler, wollastonite filler, talc filler), or metal Oxide (cerium oxide, aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, etc.) fillers are more preferred, and silica fillers are still more preferred.

At least a part of the surface of the inorganic filler is a silane coupling agent (3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane , 3-methacryloxypropyltriethoxysilane, 3-isocyanate propyltriethoxysilane, etc.) are preferably surface-treated.

D50 of the inorganic filler is preferably 20 μm or less, and more preferably 10 μm or less. As for D50, 0.01 micrometer or more is preferable and 0.1 micrometer or more is more preferable.

The shape of the inorganic filler may be granular, acicular (fibrous), or plate-like. Specific shapes of the inorganic filler include spherical shape, scale shape, layered shape, lobed shape, pinnate shape, columnar shape, crown shape, equiaxed shape, leaf shape, mica shape, and block shape. , plate shape, wedge shape, rosette shape, mesh shape, and prismatic shape.

An inorganic filler may be used individually by 1 type, and may use 2 or more types together. When the present dispersion further contains an inorganic filler, the amount thereof is preferably from 1 to 50% by mass, more preferably from 5 to 40% by mass, based on the total mass of the present dispersion.

Preferred specific examples of the inorganic filler include silica fillers (“Adma Fine (registered trademark)” series manufactured by Admatechs, etc.), zinc oxide surface-treated with esters such as propylene glycol dicaprate (Sakai Chemical Industry Co., Ltd. "FINEX" series manufactured by Ishihara Co., etc.), spherical fused silica ("SFP" series manufactured by Denka Co., etc.), titanium oxide coated with polyhydric alcohols and inorganic materials ("TAIPAKE" series manufactured by Ishihara Sangyo Co., etc.), and alkylsilanes. Surface-treated rutile titanium oxide ("JMT" series manufactured by Teika Co., Ltd.), hollow silica fillers ("E-SPHERES" series manufactured by Taiheiyo Cement Co., Ltd., "Silinax" series manufactured by Nittetsu Mining Co., Ltd., "Ecocosphere" series manufactured by Emerson & Cumming, etc.), talc filler ("SG" series manufactured by Nippon Talc, etc.), steatite filler ("BST" series manufactured by Nippon Talc, etc.), boron nitride filler ("UHP" series manufactured by Showa Electric Co., Ltd., "Denka boron nitride" series manufactured by Denka Corporation ("GP", "HGP" grade), etc.).

In addition to the above components, the present dispersion contains a thixotropic agent, a viscosity modifier, an antifoaming agent, a silane coupling agent, a dehydrating agent, a plasticizer, a weathering agent, an antioxidant, a heat stabilizer, a lubricant, and an antistatic agent, in addition to the above components, within a range that does not impair the effect of the present invention. , a brightener, a coloring agent, a conductive agent, a mold release agent, a surface treatment agent, a flame retardant, and other components such as various fillers may be further included.

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

The tick ratio of this dispersion is preferably 1.0 or more. The tick ratio of this dispersion is preferably 3.0 or less, and more preferably 2.0 or less. In this case, the present dispersion is excellent in coatability and homogeneity, and it is easy to form more dense moldings (such as polymer layers).

The pH of this dispersion liquid is 5-10. In this dispersion, the functions of the imide-based resin P are balanced by adjusting the pH within this range. That is, when the pH of the dispersion is less than 5, the reactivity of the imide-based resin P is increased, but the dispersing action is lowered, and the dispersion stability of the dispersion is lowered. Further, when the pH of the dispersion is higher than 10, the dispersing action of the imide-based resin P is increased, but the reactivity is lowered, and the physical properties of the molded article obtained from the dispersion are lowered. As for pH of this dispersion liquid, 7-9 are preferable. In this case, the color and long-term storage stability of the present dispersion tend to be excellent.

In this dispersion, the dispersion layer ratio is preferably 60% or more, more preferably 70% or more, and still more preferably 80% or more. Here, the dispersion layer ratio is the height of the entire dispersion in the screw tube and the sedimentation layer (dispersion layer) after the dispersion liquid (18 mL) is put into a screw tube (inner volume: 30 mL) and left still at 25°C for 14 days. It is a value calculated by the following formula from the height of . In addition, when the sedimentation layer is not confirmed after stationary and there is no change in state, it is assumed that there is no change in the height of the entire dispersion, and the dispersion layer ratio is set to 100%.

Dispersion layer ratio (%) = (height of sedimentation layer) / (height of the entire dispersion) × 100

This dispersion is excellent in dispersion stability, particularly long-term storage stability, due to the mechanism of action described above. The fluctuation range (absolute value) of the tick ratio of this dispersion before and after stationary when this dispersion is left still at 25 degreeC for 30 days is preferably 3 or less, and is preferably less than 1.

This dispersion can be prepared by mixing F particles, imide-based resin P, and water as a dispersion medium. As a mixing method, the F particle|grains and imide type resin P are added together or sequentially added to water, and they are mixed; A method of mixing the F particles and water, imide-based resin P and water in advance, respectively, and further mixing the obtained two mixtures; etc. can be mentioned. In this dispersion, after dispersing F particles in water in advance, imide-based resin P is added as it is (directly) or in a mixed state with water, and the dispersion is prepared in the order of mixing, or imide-based resin P in water After mixing in advance, it is advantageous from the viewpoint of more uniformly dispersing the F particles to prepare in the order of adding and mixing the F particles as they are (directly) or in a state mixed with water, and it is preferable. In addition, when surfactants, other resin materials, or inorganic fillers are further contained in the present dispersion, it is preferable to add them simultaneously when the F particles are previously dispersed in water or to add them in advance to the water before dispersing the F particles. desirable.

As a mixing method for preparing this dispersion, for example, a stirring device having single or multi-axis blades (stirring blades) such as propeller blades, turbine blades, paddle blades, shell blades, Henschel mixers, pressure kneaders , agitation by a Banbury mixer or a planetary mixer; Media such as ball mill, attritor, basket mill, sand mill, sand grinder, dyno mill (bead mill using grinding media such as glass beads or zirconium oxide beads), disper mat, SC mill, spike mill or agitator mill Mixing by a disperser using; Dispersing machines that do not use media, such as high-pressure homogenizers such as microfluidizers, nanomizers, and altimizers, ultrasonic homogenizers, dissolvers, dispersers, high-speed impeller dispersers, rotational revolution stirrers, thin-film orbital high-speed mixers, etc. Mixing using

A preferred embodiment of the method for producing the dispersion is a method in which a composition containing F particles and water is kneaded to obtain a kneaded product, and the kneaded product and water are further mixed. In that case, the imide-based resin P may be added to the composition or when further mixing the kneaded material and water, the former is preferable. That is, an aspect in which F particles, imide-based resin P, and a composition containing water are kneaded to obtain a kneaded product, and the kneaded product and water are further mixed is preferable.

Kneading can be carried out by the above-described mixing method, and it is preferable to use a Henschel mixer, pressure kneader, Banbury mixer, rotational revolution stirrer or planetary mixer, and more preferably use a planetary mixer.

The planetary mixer has a structure in which the kneaded material in the stirring tank is stirred and kneaded by having two shaft stirring blades that mutually rotate and revolve. Therefore, there is little dead space where the stirring blades do not reach in the stirring vessel, the load on the blades is reduced, and the composition can be highly kneaded. In short, since it is possible to knead the F particles and the imide-based resin P while highly interacting with the F particles while wetting the F particles with water while suppressing aggregation of the F particles, further mixing the kneaded product with water provides excellent dispersion stability. Dispersion is easy to obtain. In addition, it is easy to adjust the component concentration of the present dispersion, and it is easy to obtain the present dispersion capable of forming a thick molded product (such as a polymer layer) having excellent surface smoothness and uniformity.

The content of F particles in the composition is preferably 20% by mass or more, and more preferably 40% by mass or more, with respect to the total mass of the composition. As for content of F particle|grains, 90 mass % or less is preferable. Moreover, 0.1 mass % or more is preferable with respect to the total mass of a composition, and, as for content of imide-type resin P in a composition, 0.3 mass % or more is more preferable. As for content of imide-type resin P, 10 mass % or less is preferable.

It is preferable that it is 40 mass % or more with respect to the total mass of the composition, and, as for the total content of F particle|grains and imide type resin P in a composition, it is more preferable that it is 60 mass % or more. It is preferable that the said total content is 90 mass % or less.

Further, 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, still more preferably 0.01 or more. The ratio is preferably 0.1 or less, more preferably 0.09 or less, and still more preferably 0.05 or less.

If the content of the F particles, the content of the imide resin P, or the ratio is in such a low range, the F particles and the imide resin P can be kneaded while highly interacting in the kneading of the composition. Therefore, when the kneaded product is further mixed with water, the present dispersion excellent in dispersion stability, in which the ratio of the mass of the imide resin P to the mass of the F particles is in the range of 0.001 to 0.1, is easily obtained.

The kneaded product is a semi-solid or solid kneaded product, and is preferably a kneaded paste or lead powder. In addition, the kneaded paste is a kneaded product in a fluid and viscous state, and the softened powder means a kneaded product in a bulk or clay state.

The viscosity of the kneaded paste is preferably 800 to 100000 mPa·s, and more preferably 1000 to 10000 mPa·s or more.

It is preferable that it is 50 mass % or less, and, as for the moisture content of lead powder, it is preferable that it is 40 mass % or less. It is preferable that it is 20 mass % or more, and, as for the moisture content of lead powder, it is more preferable that it is 25 mass % or more.

In this aspect, when a surfactant, other resin material, or inorganic filler is further contained in the dispersion, these may be added to the composition or may be added at the time of mixing the kneaded material and water.

This dispersion containing another resin material or inorganic filler is obtained by kneading F particles, another resin material or inorganic filler, and a composition containing water to obtain a kneaded product, You may obtain by mixing a mixture. In this case, the dispersion stability and long-term storage stability of the present dispersion are likely to be improved.

This dispersion is excellent in dispersion stability and long-term storage stability, and can form molded products that exhibit excellent flexibility such as bending resistance, that is, excellent crack resistance, and strong adhesion to substrates.

Applying this dispersion to at least one surface of a substrate to form a liquid coating, heating the liquid coating to remove the dispersion medium to form a dry coating, and further heating the dried coating to sinter the F polymer, the F polymer and A layered product (hereinafter also referred to as "this layered product") having a polymer layer containing the resin P (hereinafter also referred to as "F layer") on the surface of a base material is obtained.

Further, when this dispersion is applied to both surfaces of a substrate and heated to sinter the F polymer, a laminate having F layers on both sides of the substrate layer constituted by the substrate is obtained.

As the base material, a metal substrate (metal foil, such as copper, nickel, aluminum, titanium, alloys thereof, etc.), a resin film (tetrafluoroethylene-based polymer, polyimide, polyarylate, polysulfone, polyallylsulfone, polyamide, A heat-resistant resin film containing at least one heat-resistant resin such as polyetheramide, polyphenylene sulfide, polyallyl ether ketone, polyamideimide, liquid crystalline polyester, or liquid crystalline polyesteramide, whether it is a single layer film or a multilayer film. ), prepregs (precursors of fiber-reinforced resin substrates), ceramic substrates (ceramic substrates such as silicon carbide, aluminum nitride, and silicon nitride), and glass substrates. Among them, a resin film is preferable, and it is more preferable that the resin constituting the resin film is a polyimide-based resin.

This dispersion liquid is preferably used for forming the F layer by applying to at least one surface of a resin film and drying it.

As a shape of a base material, a flat shape, a curved shape, and an uneven shape are mentioned. Moreover, the shape of a base material may be any of a foil shape, a plate shape, a film shape, and a fibrous shape.

As a method for applying the dispersion to the surface of a substrate, any method may be used in which a stable liquid film (wet film) made of the dispersion is formed on the surface of a resin film (substrate), and examples include a coating method, a droplet discharge method, and an immersion method. It can be, and the coating method is preferred. If the coating method is used, a liquid film can be efficiently formed on the surface of the resin film with simple equipment.

As the coating method, spray method, roll coating method, spin coating method, gravure coating method, micro gravure coating method, gravure offset method, knife coating method, kiss coating method, bar coating method, die coating method, fountain Mayer bar method, slit A coating method, a slot die coating method, and a dip coating method are exemplified.

When drying the liquid film, the liquid film is heated at a temperature at which the dispersion medium (water) volatilizes to form a dry film on the surface of the resin film. As for the heating temperature in such drying, 100-200 degreeC is preferable. Moreover, you may blow air in the process of removing a dispersion medium.

During drying, the dispersion medium does not necessarily need to be completely volatilized, and it is only necessary to volatilize 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. As for this heating temperature, 380 degreeC or less is preferable.

As each heating method, the method of using an oven, the method of using a ventilation drying furnace, and the method of irradiating heat rays, such as infrared rays, are mentioned. 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 from 0.1 to 30 minutes, and more preferably from 0.5 to 20 minutes.

When heated under the above conditions, the F layer can be preferably formed while maintaining high productivity.

The thickness of the F layer is preferably 0.1 to 150 μm, and more preferably 10 μm or more. When the substrate layer is a metal foil, the thickness of the F layer is preferably 10 to 30 μm. When the substrate layer is a resin film, the thickness of the F layer is preferably from 10 to 150 μm, and more preferably from 15 to 50 μm.

The peel strength between the F layer and the substrate layer is preferably 10 N/cm or more, and more preferably 15 N/cm or more. The peel strength is preferably 100 N/cm or less. If this dispersion is used, such a main 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, and more preferably 20% or less. The porosity is preferably 0.1% or more, and more preferably 1% or more. From this dispersion, it is easy to form such a low porosity F layer. In particular, even when the porosity of the dry film is 1% or more, it is easy to form an F layer with a low porosity. In addition, the porosity is determined by determining the void portion of the F layer by image processing from the SEM photograph in the cross section of the molded article observed using a scanning electron microscope (SEM), and the area occupied by the void portion is the area of the F layer. is the ratio (%) divided by The area occupied by the void portion is obtained by approximating the void portion to a circular shape.

This dispersion may be applied only to one surface of the substrate or may be applied to both surfaces of the substrate. In the former, this laminate having a base layer composed of the base material and an F layer on the other surface of the base layer is obtained, and in the latter, a base layer composed of the base material and surfaces of both of the base layer are obtained. This laminated body having the F layer is obtained. Since warpage is less likely to occur in the latter main laminate, it is excellent in handling during processing.

Specific examples of such a main laminate include a metal foil and 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 heard Since these main laminates are excellent in various physical properties such as electrical properties, they are suitable as printed board materials and the like, and can be used for manufacturing flexible printed boards and rigid printed boards.

In this laminate having the F layer on both sides of the substrate layer, the dispersion is applied to one surface of the substrate, heated to remove the liquid dispersion medium, the dispersion is applied to the other surface of the substrate, and heated to remove the liquid dispersion medium. It is preferable to obtain by removing and further heating to sinter the F polymer to form each F layer.

In addition, in this laminate having the F layer on both sides of the substrate layer, the dispersion is applied to both surfaces of the substrate, heated to remove the liquid dispersion medium, further heated to sinter the F polymer, and both surfaces of the It may be obtained by simultaneously forming the F layer.

In this case, the present laminate having the F layer on both sides of the substrate layer is preferably obtained by immersing the substrate in the dispersion, applying the dispersion to both surfaces of the substrate, and then passing through a firing furnace and heating. Specifically, it is more preferable to obtain the substrate by immersing the substrate in the present dispersion and then passing the substrate through a sintering furnace while raising the substrate from the dispersion and heating.

It is preferable that the direction in which the base material is pulled up and passed through the firing furnace is vertically upward. In this case, a smooth F layer is easily formed. After pulling up the base material vertically upward, you may further heat it while pulling it down vertically, or you may take it up by pulling it up vertically downward without heating.

Further, the amount of the dispersion applied to the substrate can be adjusted by passing the substrate with the dispersion between a pair of rolls.

Such a main layered product can be preferably manufactured by using a device having a dip coater and a firing furnace. As a firing furnace, a vertical firing furnace is mentioned. Moreover, as such an apparatus, the Tabata Machinery Co., Ltd. glass cloth coating apparatus is mentioned.

Here, the outermost surface of the base material may be further subjected to surface treatment in order to further improve its low linear expansion property and adhesiveness.

Examples of the surface treatment include annealing treatment, corona treatment, plasma treatment, ozone treatment, excimer treatment, and silane coupling treatment.

As for the conditions in the annealing treatment, it is preferable to set the temperature to 120 to 180°C, set the pressure to 0.005 to 0.015 MPa, and set the time to 30 to 120 minutes.

Examples of the gas used for the plasma treatment include oxygen gas, nitrogen gas, rare gas (such as argon), hydrogen gas, ammonia gas, and vinyl acetate. These gases may use 1 type or may use 2 or more types together.

As for the 10-point average roughness of the surface of a base material, 0.01-0.05 micrometer is preferable.

This layered product in which the substrate layer is a resin film (preferably a polyimide film) is useful as a release film or a carrier film. Since this layered product has excellent adhesion between the F layer and the substrate layer and is difficult to separate between the layers, it can be used repeatedly as a carrier film. Moreover, since F layer is excellent in heat resistance, releasability is hard to deteriorate even if it is used repeatedly.

Specifically, a dispersion liquid or varnish containing a resin or inorganic filler is applied to the surface of the F layer of this laminate, dried to form a coating film, and then, when the laminate is peeled from the coating film, an independent coating film is formed. is obtained For example, after forming the above coating film on the surface of the F layer of the present laminate, bonding the other substrate to the coating film side of the present laminate having such a coating film, and peeling the present laminate, the lamination of the other substrate and the coating film body is obtained.

When forming a coating film on the surface of the F layer of this laminate, you may heat at a temperature below the melting|fusing point of F polymer at the time of drying, for example. Since this laminate is excellent in heat resistance, it is hard to deform|transform even if it heat-processes repeatedly.

Specifically, this laminate is useful as 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 for a solid polymer electrolyte membrane.

When using this layered product as a carrier film, the ratio of the thickness of the edge to the thickness of the central portion of the present layered product is preferably 1.1 or less, more preferably 1.07 or less, from the viewpoint of obtaining the coating film having a uniform thickness. , 1.04 or less is more preferable. The ratio of the thickness is 1 or more.

On the outermost surface of this laminate, another substrate may be further laminated.

Examples of the other substrate include a metal substrate, a heat-resistant resin film, a prepreg that is a precursor of a fiber-reinforced resin board, a laminate having a heat-resistant resin film layer, and a laminate having a prepreg layer.

In addition, prepreg is a sheet-like substrate in which a base material (rattan, woven fabric, etc.) of reinforcing fibers (glass fiber, carbon fiber, etc.) is impregnated with a thermosetting resin or thermoplastic resin.

As a metal substrate, the metal substrate mentioned above is mentioned. The heat-resistant resin film is a film containing one or more types of heat-resistant resin, and the above-described resin is exemplified as the heat-resistant resin.

As the lamination method, a method of hot-pressing the present laminate and another substrate is exemplified.

As for the hot press conditions when the other substrates are prepregs, the temperature is preferably 120 to 400°C, the atmospheric pressure is vacuum of 20 kPa or less, and the press pressure is preferably 0.2 to 10 MPa. Since such a present laminate has an F layer with excellent electrical properties, it is suitable as a printed circuit board material, and can be specifically used for manufacturing a printed circuit board as a flexible metal clad laminate or a rigid metal clad laminate. In particular, flexible metal clad laminates As a laminated board, it can be used suitably for manufacture of a flexible printed circuit board.

This layered product in which the substrate layer is metal foil (metal foil with F layer) and the metal clad layered product in which metal foil is further laminated on this layered product in which the base layer is a resin film and has an F layer (resin film and metal foil with F layer) A printed circuit board is obtained by subjecting the metal foil to an etching process and forming a transmission circuit. Specifically, by a method of processing metal foil into a predetermined transmission circuit by etching, or by a method of processing metal foil into a predetermined transmission circuit by an electrolytic plating method (semi-additive method (SAP method), MSAP method, etc.), A printed board can be manufactured.

A printed circuit board manufactured from metal foil with F layer and resin film, and metal foil with F layer has a transmission circuit formed from metal foil and F layer in this order. Specific examples of the structure of the printed board include transmission circuit/F layer/prepreg layer, transmission circuit/F layer/prepreg layer/F layer/transmission circuit, transmission circuit/F layer/polyimide film layer, transmission circuit/ F layer/polyimide film layer/F layer/transmission circuit.

In manufacturing such a printed board, an interlayer insulating film may be formed on the transfer circuit, a solder resist may be laminated on the transfer circuit, or a coverlay film may be laminated on the transfer circuit. You may form these interlayer insulating films, a solder resist, and a coverlay film with this dispersion liquid.

Since this multilayer body in which the base layer is a metal substrate is excellent in insulation and heat dissipation, it is also useful as a heat dissipation substrate, and can be particularly suitably used as a power semiconductor mounting substrate.

The shape of the base material in such a case is preferably plate-shaped, and as the base material, a copper plate or an aluminum plate is preferable. As for the thickness of a base material, 0.1-3 mm is preferable.

In the production of this laminate in such a case, a slit coating method is preferable as a method of applying the present dispersion to a substrate.

As the F polymer in this 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 this case, an aromatic polyimide, an aromatic polyimide precursor, an aromatic polyamideimide or an aromatic polyamideimide precursor is preferable.

In this case, the F layer preferably further contains an inorganic filler. As the inorganic filler, a boron nitride filler, an aluminum nitride filler or an aluminum oxide filler is preferable.

In short, in this laminate used as a heat dissipation substrate, polymer F is a polymer having an oxygen-containing polar group containing the above-described TFE units and PAVE units, and the imide-based resin P is an aromatic polyimide, an aromatic polyimide precursor, It is preferably an aromatic polyamideimide or an aromatic polyamideimide precursor, and it is preferable that a boron nitride filler, an aluminum nitride filler, or an aluminum oxide filler is contained in the F layer. In this case, the insulation and heat dissipation properties of this laminate as a heat dissipation substrate are particularly likely to be improved.

When using this laminated body as a heat radiation board|substrate, it is preferable to process and use this laminated body as the laminated body which has a metal layer, an F layer, and a metal layer in this order. Such a laminate may be obtained by thermally pressing a metal substrate to the surface of the F layer of the main laminate, or by laminating two main laminates so that the F layers face each other and thermally compressing the F layer, The latter is preferred.

As a method of thermal compression bonding, hot press is preferable.

The thicknesses of the two metal layers in such a laminate may be the same or different. In addition, the metal in the two metal layers may be the same or different.

For example, when the F layer of this laminate having the F layer on the surface of a 1 mm thick aluminum plate and the F layer of this laminate having the F layer on the surface of a 0.5 mm thick copper plate are hot-pressed and bonded by thermal compression, A laminated body having an aluminum plate, an F layer, and a copper plate in this order and having two metal layers with different thicknesses is obtained.

This laminate or a laminate of this laminate and other substrates is useful as antenna parts, printed circuit boards, aircraft parts, automobile parts, sports equipment, food industrial goods, paints, heat dissipation parts, cosmetics, etc. Specifically, , wire covering materials (aircraft wires, etc.), electrical insulation tapes, insulation tapes for oil drilling, materials for printed circuit boards, separators (microfiltration membranes, ultrafiltration membranes, reverse osmosis membranes, ion exchange membranes, dialysis membranes, gas separation membranes, etc.), electrode binders ( lithium secondary batteries, fuel cells, etc.), copy rolls, furniture, automobile dashboards, covers of home appliances, sliding members (load bearings, sliding shafts, valves, bearings, gears, cams, belt conveyors, food transport belts, etc.) , tools (shovels, files, awls, saws, etc.), boilers, hoppers, pipes, ovens, grills, chutes, dies, toilet bowls, container coverings, mounting heat dissipation boards for power devices, transistors, thyristors, rectifiers, transformers, power MOS FETs, CPUs, heat dissipation fins, metal heat sinks, blades of windmills, wind turbines, aircraft, etc., casings of personal computers and displays, electronic device members, interior and exterior members of automobiles, processing machines that heat-process under low oxygen, vacuum ovens, and plasma processing It is useful as a sealing member of an apparatus, etc., a heat dissipation component in a processing unit such as a sputter or various dry etching devices, and an electromagnetic shield member.

In the above, the present dispersion liquid, the manufacturing method of the present dispersion liquid, and the present laminate have been described, but the present invention is not limited to the configuration of the above-described embodiment. For example, in the configuration of the above embodiment, the present dispersion liquid and the present laminate may be added with other arbitrary components, or may be substituted with an arbitrary configuration exhibiting the same function. In addition, the manufacturing method of this dispersion liquid may further have another arbitrary process in the structure of the said embodiment, and may be substituted with the arbitrary process which produces the same action.

Example

Hereinafter, the present invention will be described in detail by examples, but the present invention is not limited thereto.

1. Details of each component

[F particle]

Particle F 1: A polymer containing 97.9 mol%, 0.1 mol%, and 2.0 mol% of TFE units, NAH units, and PPVE units in this order, and having 1000 carbonyl group-containing groups per 1 × 10 ⁶ carbon atoms in the main chain (melting temperature: 300 ° C) (D50: 2.1 μm)

Particle F 2: Particles made of a polymer (melting temperature: 305°C) 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 carbon atoms in the main chain (D50 : 1.8 μm)

Particle F 3: Particles made of non-heat-meltable PTFE (D50: 0.2 μm)

[F Dispersion]

F dispersion 1: Aqueous dispersion containing 60% by mass of F particles 3 ("AD-911E" manufactured by AGC)

[Varnish of imide-based resin]

Varnish 1: Water varnish containing a precursor of aromatic polyamideimide (PAI 1) (acid value: 50 mgKOH/g)

[Surfactants]

Surfactant 1: Polyoxyalkylene-modified polydimethylsiloxane having a dimethylsiloxane unit in the main chain and an oxyethylene group in the main chain terminal or side chain (weight average molecular weight: 1600, degree of dispersion: 1.5, HLB value: 13, static surface Tension: 25 mN/m, dynamic surface tension of 0.1% by mass aqueous solution: 30 mN/m)

[pH adjusting agent]

Amine 1: triethanolamine

Acid 1: Formic acid

[Non-ionic polymer]

Polysaccharide 1: Hydroxyethyl cellulose ("HEC CF-Y" manufactured by Sumitomo Seiki Co., Ltd.) [a water-soluble polymer having a nonionic hydroxyl group]

[Resin film (substrate)]

Polyimide film 1: Aromatic polyimide film with a thickness of 25 μm (“FG-100” manufactured by PI Advanced Materials)

2. Preparation and Evaluation of Dispersions

[Example 1-1]

Into the pot, F particle 1, varnish 1, surfactant 1, and water were put, and zirconia balls were put. Thereafter, 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 (46.4 parts by mass) ) to obtain a dispersion 1 containing The viscosity of the obtained dispersion liquid 1 was 1000 mPa·s, and the pH was 8.0.

In dispersion 1, even when stored at 25°C for a long period of time, aggregates were not visually recognized, and the dispersibility was excellent.

[Example 1-2]

Into the pot, F Particle 1, varnish 1, surfactant 1, and water were introduced and mixed to prepare a composition. After kneading this composition in a planetary mixer, it was taken out, and a mixture 1 containing 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) got

It stirred, degassing at 2000 rpm with the rotational revolution stirrer, adding water divided into several times to the compound 1. Further, water was added in a plurality of times while stirring, 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 (46.4 parts by mass) A dispersion 2 containing 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]

Into the pot, F Particle 1, varnish 1, surfactant 1, and water were introduced and mixed to prepare a composition. After kneading this composition in a planetary mixer, it was taken out, and a compound 7 containing F particles 1 (50 parts by mass), PAI 1 (0.6 parts by mass), surfactant 1 (3 parts by mass) and water (20 parts by mass) got

To the compound 7, the F dispersion liquid 1 was added, and further, while dividing and adding water in a plurality of times, it was stirred while degassing at 2000 rpm with an autorotation/revolution stirrer. Further, water was added in a plurality of times while stirring, amine 1 was added, F particles 1 (50 parts by mass), F particles 3 (10 parts by mass), PAI 1 (0.6 parts by mass), surfactant 1 (3 parts by mass) Part) and water (46.4 parts by mass), a dispersion 7 was obtained. The viscosity of the obtained dispersion liquid 7 was 700 mPa·s, and the pH was 8.0.

[Example 1-8]

Into the pot, F Particle 1, varnish 1, surfactant 1, polysaccharide 1, and water were introduced and mixed to prepare a composition. After kneading this composition in a planetary mixer, it was taken out, and F particles 1 (50 parts by mass), PAI 1 (0.6 parts by mass), surfactant 1 (3 parts by mass), polysaccharide 1 (0.3 parts by mass), and water (20 parts by mass). mass part) was obtained.

The F dispersion liquid 1 was added to the compound 8, and it stirred, defoaming at 2000 rpm with the rotation-revolution stirrer, adding water separately in multiple times. Further, water was added in a plurality of times while stirring, amine 1 was added, F particles 1 (50 parts by mass), F particles 3 (10 parts by mass), PAI 1 (0.6 parts by mass), surfactant 1 (3 parts by mass) part), polysaccharide 1 (0.3 parts by mass) and water (46.1 parts by mass), a dispersion 8 was obtained. The viscosity of the obtained dispersion liquid 8 was 3000 mPa·s, and the pH was 8.0.

3. Manufacturing and Evaluation of Laminates

[Example 2-1]

In a roll-to-roll process, the dispersion 1 obtained in Example 1-1 was applied to one side of the polyimide film 1 by a small-diameter gravure reverse method, and then dried in an air drying furnace (no temperature 150 ° C.) for 3 minutes. It was passed through and 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 with dry films formed on both sides was passed through a far infrared ray furnace (furnace temperature 300 ° C. near the inlet and outlet of the furnace, furnace temperature 360 ° C. near the center) for 5 minutes, and the F particles 1 were melt-sintered.

Thereby, a polymer layer containing the melt-sintered product of F particle 1 and PAI 1 is formed on both sides of the polyimide film 1, and a laminate (multilayer film 1) in which the polymer layer, the polyimide film layer, and the polymer layer are directly formed in this order ) was obtained by a roll-to-roll process. The thickness of the polymer layer in multilayer film 1 was 25 μm.

[Example 2-2] ~ [Example 2-8]

Instead of the dispersion liquid 1, except having used the dispersion liquids 2-8, it carried out similarly to Example 2-1, and obtained multilayer films 2-7.

The porosity of the polymer layer of each multilayer film was small 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 most dense.

4. Evaluation

4-1. Evaluation of the dispersion layer ratio of the dispersion

Each dispersion liquid (18 mL) was placed in a screw tube (inner volume: 30 mL), and left still at 25°C for 14 days. The dispersion layer ratio was calculated by the following formula from the height of the entire dispersion liquid in the screw tube after standing and the height of the sedimentation layer (dispersion layer), and the dispersion stability was evaluated according to the following criteria.

[Evaluation standard]

○: The dispersion layer ratio is 80% or more.

(triangle|delta): The dispersion|distribution layer ratio is 60 % or more and less than 80.

x: The dispersion layer ratio is less than 60%.

4-2. Fluctuation of the tick ratio of the dispersion

Each dispersion liquid was stored in a container at 25°C for 30 days, and the fluctuation range of thixotropic ratio before and after storage was measured, and thixotropic stability was evaluated according to the following criteria.

[Evaluation standard]

○: The fluctuation range (absolute value) of the tick consumption is less than 1.

△: The fluctuation range (absolute value) of the tick consumption is 1 or more and 3 or less.

x: The fluctuation range (absolute value) of tick consumption is greater than 3.

4-3. Evaluation of surface smoothness of multilayer films

The surface of the polymer layer of each multilayer film was visually confirmed, and surface smoothness was evaluated according to the following criteria.

[Evaluation standard]

○: There is no pinhole on the surface of the polymer layer.

×: There is a pinhole on the surface of the polymer layer.

4-4. Evaluation of interlayer adhesion of multilayer films

A rectangular (length 100 mm, width 10 mm) test piece was cut out from each multilayer film, a position of 50 mm from one end in the longitudinal direction of the test piece was fixed, and a tensile speed of 50 mm/min was applied to the test piece from one end in the longitudinal direction. The polymer layer and the polyimide film layer were separated at an angle of 90° to each other. The maximum load applied at that time was taken as peel strength, and interlayer adhesion was evaluated according to the following criteria.

[Evaluation standard]

○: Peel strength is 15 N/cm or more.

(triangle|delta): Peel strength is 10 N/cm or more and less than 15 N/cm.

x: Peel strength is less than 10 N/cm.

Each evaluation result is put together and shown in Table 2 below.

Further, 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 multilayer films 7 and 8 was the lowest, and both multilayer films had excellent electrical properties. was better. In addition, the thickness of the polymer layer having surface smoothness and interlayer adhesion that can be formed in a single laminate production 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 laminates (metal foil 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 industrial goods, sliding bearings and the like. In addition, since the laminate of the present invention has excellent 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 membrane, and a catalyst for a solid polymer electrolyte membrane It can also be used as a carrier film for formation.

Claims (15)

An aqueous dispersion liquid containing tetrafluoroethylene-based polymer particles, an aromatic imide-based resin having an acid value of 20 to 100 mg/KOH, and water, and having a pH of 5 to 10. According to claim 1,
An aqueous dispersion, wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having oxygen-containing polar groups including perfluoro(alkylvinyl ether)-based units. According to claim 1 or 2,
An aqueous dispersion liquid in which the particles of the tetrafluoroethylene-based polymer include particles of a non-heat-melting tetrafluoroethylene-based polymer and particles of a heat-melting tetrafluoroethylene-based polymer. According to any one of claims 1 to 3,
An aqueous dispersion in which the aromatic imide-based resin is a water-soluble aromatic polyamideimide precursor or a water-soluble aromatic polyimide precursor. According to any one of claims 1 to 4,
Additionally, an aqueous dispersion comprising an inorganic filler. According to any one of claims 1 to 5,
Additionally, an aqueous dispersion comprising a nonionic surfactant. According to any one of claims 1 to 6,
Furthermore, an aqueous dispersion containing at least one nonionic polymer selected from the group consisting of polyvinyl alcohol-based polymers, polyvinylpyrrolidone-based polymers, and polysaccharides. According to any one of claims 1 to 7,
Aqueous dispersions, containing amines or ammonia. According to any one of claims 1 to 8,
The aqueous dispersion liquid, wherein the ratio of the mass of the aromatic imide-based resin to the mass of the particles of the tetrafluoroethylene-based polymer is in the range of 0.001 to 0.1. According to any one of claims 1 to 9,
The aqueous dispersion, 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. According to any one of claims 1 to 10,
An aqueous dispersion having a viscosity of 50 to 3000 mPa·s. According to any one of claims 1 to 11,
An aqueous dispersion used to form a polymer layer containing a tetrafluoroethylene-based polymer by applying and heating to at least one surface of a resin film. According to any one of claims 1 to 12,
An aqueous dispersion liquid in which the resin constituting the resin film is a polyimide-based resin. Claims 1 to 3 wherein the particles of the tetrafluoroethylene-based polymer, the aromatic imide-based resin, and a composition containing water are kneaded to obtain a kneaded product, and the aqueous dispersion is obtained by mixing the kneaded product and water. A method for producing the aqueous dispersion according to any one of Claims 13 to 13. Consisting of the resin film obtained by applying the aqueous dispersion according to any one of claims 1 to 13 to both surfaces of a resin film and heating to form the polymer layer containing a tetrafluoroethylene-based polymer. A laminate having the polymer layer on both sides of a substrate layer.