WO2021221038A1

WO2021221038A1 - Method for producing dispersion, paste, and kneaded powder

Info

Publication number: WO2021221038A1
Application number: PCT/JP2021/016727
Authority: WO
Inventors: 敦美山邊
Original assignee: Ａｇｃ株式会社
Priority date: 2020-04-30
Filing date: 2021-04-27
Publication date: 2021-11-04
Also published as: KR20230002304A; JPWO2021221038A1; CN115516008A; TW202144071A

Abstract

Provided are: a method for producing a dispersion which includes a powder of a tetrafluoroethylene-based polymer and either an inorganic filler or a resin different from the tetrafluoroethylene-based polymer and is excellent in terms of dispersibility; a paste; and a kneaded powder.　The method for producing a dispersion comprises kneading a powder of a tetrafluoroethylene-based polymer, at least one other material selected from the group consisting of inorganic fillers and resins different from the tetrafluoroethylene-based polymer, and a liquid compound to obtain a kneaded mixture and mixing the kneaded mixture with a liquid compound to obtain the dispersion. The paste or kneaded powder is obtained by kneading a powder of a tetrafluoroethylene-based polymer and said other material.

Description

Dispersion manufacturing method, paste and kneading powder

The present invention relates to a method for producing a dispersion liquid containing a tetrafluoroethylene polymer powder and a predetermined other material, and a paste and kneaded powder preferably used in the production method.

The tetrafluoroethylene polymer is excellent in physical properties such as electrical insulation, water and oil repellency, chemical resistance, and heat resistance. Therefore, the dispersion liquid in which the powder is dispersed in water or an oil-based solvent is useful as a material for forming a resist, an adhesive, an electrically insulating layer, a lubricant, an ink, a paint, and the like. However, the tetrafluoroethylene polymer has a low surface energy, and the powders tend to aggregate with each other. Therefore, it is difficult to obtain a low-viscosity dispersion having excellent dispersion stability.
For example, Patent Document 1 discloses a non-aqueous dispersion liquid using an additive from the viewpoint of improving the dispersibility of the dispersion liquid and adjusting the physical characteristics of the dispersion liquid.

International Publication 2016/159102

However, the dispersion stability of the dispersion liquid described in Patent Document 1 is still insufficient.
Further, the dispersion liquid containing the powder of the tetrafluoroethylene-based polymer and further added with other functional materials such as an inorganic filler or a resin different from the tetrafluoroethylene-based polymer has other functionalities in the molded product formed from the dispersion. There is a possibility that the physical properties of the material can also be imparted.

However, the affinity between the tetrafluoroethylene polymer and other functional materials is generally low, and the dispersion stability of such a dispersion tends to be further lowered.
In addition, when adding other functional materials, if high shear is applied to disperse the tetrafluoroethylene polymer powder, air entrainment, alteration of the tetrafluoroethylene polymer, etc. will cause foaming and agglutination. It is easy to occur.
As a result, in the molded product obtained from the dispersion liquid, the uniformity of the component distribution and the water resistance due to the generation of voids tend to decrease.

The present inventors have excellent dispersion stability, which contains a powder of a tetrafluoroethylene-based polymer and at least one other material selected from the group consisting of an inorganic filler and a resin different from the tetrafluoroethylene-based polymer. In order to obtain a solid dispersion, a method for producing such a dispersion was studied, and the present invention was completed.
The present invention provides a method for producing a dispersion liquid containing a tetrafluoroethylene polymer powder and the above-mentioned other materials and having excellent dispersion stability, and a paste and a kneaded powder preferably used in the production method. The purpose.

The present invention has the following aspects.
[1] A kneaded product is obtained by kneading a powder of a tetrafluoroethylene polymer, at least one other material selected from the group consisting of an inorganic filler and a resin different from the tetrafluoroethylene polymer, and a liquid compound. , A method for producing a dispersion liquid, wherein the kneaded product and a liquid compound are mixed to obtain a dispersion liquid.
[2] The production method according to [1], wherein the solid content of the kneaded product is 40% by mass or more.
[3] The kneaded product contains the inorganic filler, and the ratio of the powder to the inorganic filler in the kneaded product is such that the mass of the powder is 1 and the mass of the inorganic filler is 0.5 to 2. There is a manufacturing method of [1] or [2].
[4] The production method according to any one of [1] to [3], wherein the inorganic filler is a silica filler or a boron nitride filler.
[5] The kneaded product contains the different resin, and the ratio of the powder to the different resin in the kneaded product is 0.01 to 0.5, where the mass of the powder is 1, and the mass of the different resin is 0.01 to 0.5. The production method according to any one of [1] to [4].
[6] The kneaded product contains the different resin, and the ratio of the powder to the different resin in the kneaded product is 1 for the mass of the powder and 2 to 1000 for the mass of the different resin. The production method according to any one of 1] to [4].
[7] The production method according to any one of [1] to [6], wherein the different resin is an aromatic polymer.
[8] The production method according to any one of [1] to [7], wherein the liquid compound is a low-viscosity liquid or a high-viscosity liquid.
[9] A powder of a tetrafluoroethylene polymer, a resin different from the tetrafluoroethylene polymer, a liquid compound and a surfactant are kneaded to obtain a kneaded product, and the kneaded product and the liquid compound are mixed to prepare a dispersion liquid. A method for producing a dispersion liquid.
[10] A mixture containing a tetrafluoroethylene polymer powder and an inorganic filler and a mixture containing a resin and a liquid compound different from the tetrafluoroethylene polymer are kneaded to obtain a kneaded product, and the kneaded product and the liquid are obtained. A method for producing a dispersion, which comprises mixing with a compound to obtain a dispersion.
[11] A solid obtained by kneading a powder of a tetrafluoroethylene polymer, at least one other material selected from the group consisting of an inorganic filler and a resin different from the tetrafluoroethylene polymer, and a liquid compound. A paste having a quantity of 40% by mass or more and a viscosity of 800 to 100,000 mPa · s.
[12] The paste according to [11], which contains the inorganic filler and has a ratio of the powder to the inorganic filler, wherein the mass of the powder is 1 and the mass of the inorganic filler is 0.5 to 2.
[13] [11] or [11] or [13], which contains the different resins, the ratio of the powder to the different resins is 0.01 to 0.5, where the mass of the powder is 1. 12] paste.
[14] A kneading obtained by kneading a powder of a tetrafluoroethylene polymer, at least one other material selected from the group consisting of an inorganic filler and a resin different from the tetrafluoroethylene polymer, and a liquid compound. powder.
[15] The kneaded powder of [14], which contains the different resins, and the ratio of the powder to the different resins is 0.01 to 0.5, where the mass of the powder is 1, and the mass of the different resins is 0.01 to 0.5. ..

According to the present invention, it is excellent in dispersion stability and contains a powder of a tetrafluoroethylene-based polymer and at least one other material selected from the group consisting of an inorganic filler and a resin different from the tetrafluoroethylene-based polymer. A dispersion can be produced. Further, according to the present invention, there are provided pastes and kneaded powders containing a powder of a tetrafluoroethylene-based polymer and other materials.

The following terms have the following meanings.
The "tetrafluoroethylene-based polymer" is a polymer containing a unit based on tetrafluoroethylene, and is also simply referred to as "F polymer".
The "glass transition point (Tg) of the polymer" is a value measured by analyzing the polymer by the dynamic viscoelasticity measurement (DMA) method.
The “polymer melting temperature (melting point)” is the temperature corresponding to the maximum value of the melting peak measured by the differential scanning calorimetry (DSC) method.
“D50” is the average particle size of the object (powder and filler), and is the volume-based cumulative 50% diameter of the object determined by the laser diffraction / scattering method. That is, the particle size distribution of the object is measured by the laser diffraction / scattering method, the cumulative curve is obtained with the total product of the group of the objects as 100%, and the particle size at the point where the cumulative volume is 50% on the cumulative curve. be.
“D90” is the cumulative volume particle size of the object, and is the volume-based cumulative 90% diameter of the object obtained in the same manner as “D50”.
The "viscosity of the paste and the dispersion liquid" is a value measured for the dispersion liquid at room temperature (25 ° C.) and at a rotation speed of 30 rpm using a B-type viscometer. The measurement is repeated 3 times, and the average value of the measured values for 3 times is used.
The "monomer-based unit" 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 processing a polymer. Hereinafter, the unit based on the monomer a is also simply referred to as “monomer a unit”.

The production method of the present invention (hereinafter, also referred to as the present method) consists of a group consisting of an F polymer powder (hereinafter, also referred to as the present powder), an inorganic filler and a resin different from the F polymer (hereinafter, also referred to as the present different resin). At least one selected other material (hereinafter, also referred to as other material) and a liquid compound (hereinafter, also referred to as liquid compound 1) are kneaded to obtain a kneaded product (hereinafter, also referred to as this kneaded product). This is a method of mixing the kneaded product and a liquid compound (hereinafter, also referred to as liquid compound 2) to obtain a dispersion liquid (hereinafter, also referred to as the present dispersion liquid). This dispersion is a dispersion in which the powder is dispersed.

The F polymer in the present invention is a polymer containing a unit (hereinafter, also referred to as TFE unit) based on tetrafluoroethylene (hereinafter, also referred to as TFE).
The fluorine content of the F polymer is preferably 70 to 76% by mass. Such an F polymer having a high fluorine content is excellent in physical properties such as electrical properties of the F polymer, but has a low polarity, so that not only is it low in affinity with other materials, but the powder is easily aggregated. Therefore, when the dispersion liquid is prepared, its dispersibility is further lowered. According to this method, even in such a dispersion, the physical properties of the entire F polymer are not impaired, and a dispersion having excellent dispersibility can be obtained.

Since the F polymer is a polymer having a high degree of rigidity, it is considered that the F polymer is easily denatured in the dispersion liquid by the method of mixing with the dispersion medium by shearing as is generally performed to improve the dispersibility. As a result, the dispersibility of the F polymer in the dispersion medium may decrease.
According to this method, since it is possible to mix the liquid compound 1 and the liquid compound 2 without applying high shearing, the present dispersion can be obtained without impairing the dispersibility.
Further, according to this method, the dispersion liquid can be produced while suppressing the entrainment of air contained in the powder and other materials. Therefore, it is considered that a dense molded product can be obtained from this dispersion, the molded product has excellent water resistance, uniformly contains F polymer and other materials, and highly expresses the physical characteristics of both.

The melting temperature of the F polymer in the present invention is preferably 180 ° C. or higher, more preferably 200 ° C. or higher, and even more preferably 260 ° C. or higher. The melting temperature of the F polymer is preferably 325 ° C. or lower, more preferably 320 ° C. or lower. The melting temperature of the F polymer is particularly preferably 180 to 325 ° C.
The glass transition point of the F polymer is preferably 50 ° C. or higher, more preferably 75 ° C. or higher. The glass transition point of the F polymer is preferably 150 ° C. or lower, more preferably 125 ° C. or lower.

The F polymer includes a polymer containing polytetrafluoroethylene (hereinafter, also referred to as PTFE), a TFE unit and a unit based on perfluoro (alkyl vinyl ether) (hereinafter, also referred to as PAVE) (hereinafter, also referred to as PAVE unit) (hereinafter, PFA). (Also also referred to as) or a polymer containing a unit based on TFE and hexafluoropropylene (hereinafter, also referred to as FEP) is preferable, PFA or FEP is more preferable, and PFA is further preferable. These polymers may further contain units based on other comonomeres.
As the PAVE, CF ₂ = CFOCF ₃ , CF ₂ = CFOCF ₂ CF ₃ or CF ₂ = CFOCF ₂ CF ₂ CF ₃ (hereinafter, also referred to as PPVE) is preferable, and PPVE is more preferable.

The F polymer preferably has an atomic group containing an oxygen atom. According to this method, the physical characteristics of the F polymer based on such atomic groups are not impaired, and the physical characteristics of the molded product obtained by using the present dispersion are further improved.
The atomic group may be contained in the monomer unit in the F polymer, or may be contained in the terminal group of the main chain of the polymer. Examples of the latter aspect include an F polymer having the above-mentioned atomic group as a terminal group derived from a polymerization initiator, a chain transfer agent, or the like.
The atomic group containing an oxygen atom is preferably a hydroxyl group-containing group or a carbonyl group-containing group, and a carbonyl group-containing group is particularly preferable.
The number of carbonyl group-containing groups in the F polymer is preferably 10 to 5000, more preferably 100 to 3000, and even more preferably 50 to 1500, per ^{1 × 10 6 carbon atoms in the main chain.} The number of carbonyl group-containing groups in the F polymer can be quantified by the composition of the polymer or the method described in International Publication No. 2020/145133.

The hydroxyl group-containing group is preferably an alcoholic hydroxyl group-containing group, more preferably -CF ₂ CH ₂ OH or -C (CF ₃ ) ₂ OH.
The carbonyl group-containing group is a group containing a carbonyl group (> C (O)), a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC (O) NH ₂ ), and an acid anhydride residue. A group (-C (O) OC (O)-), an imide residue (-C (O) NHC (O)-etc.) or a carbonate group (-OC (O) O-) is preferred, and an acid anhydride residue. Is more preferable.

As the F polymer, a polymer containing PTFE units and PAVE units, containing 1.5 to 5.0 mol% of PAVE units with respect to all units, and having a melting temperature of 280 to 320 ° C. is preferable, and TFE units and PAVE units are used. F polymer (1) containing atomic groups containing oxygen atoms, or containing TFE units and PAVE units, containing 2 to 5 mol% of PAVE units with respect to all monomer units, and having atomic groups containing oxygen atoms. No F polymer (2) is more preferable. Since these polymers form microspherulites in the molded product, the characteristics of the molded product are likely to be improved.

The F polymer (1) is preferably a polymer containing a TFE unit, a PAVE unit, and a unit based on a monomer having a hydroxyl group-containing group or a carbonyl group-containing group. The F polymer (1) has 90 to 98 mol% of TFE units, 1.5 to 9.97 mol% of PAVE units, and 0.01 to 3 mol% of units based on the above-mentioned monomers, based on all the units. It is preferable to include each. The monomer is preferably itaconic anhydride, citraconic anhydride or 5-norbornene-2,3-dicarboxylic acid anhydride (also known as hymic anhydride; hereinafter also referred to as “NAH”).
Specific examples of the F polymer (1) include the polymers described in International Publication No. 2018/16644.

The F polymer (2) is composed of only TFE units and PAVE units, and preferably contains 95 to 98 mol% of TFE units and 2 to 5 mol% of PAVE units with respect to all the monomer units.
The content of PAVE units in the F polymer (2) is preferably 2.1 mol% or more, more preferably 2.2 mol% or more, based on all the monomer units.
The fact that the F polymer (2) does not have an atomic group containing an oxygen atom means that the number of atomic groups containing an oxygen atom contained in the polymer per ^{1 × 10 6 carbon atoms constituting the polymer main chain.} , Means less than 500 pieces. The number of atomic groups containing oxygen atoms is preferably 100 or less, more preferably less than 50. The lower limit of the number of atomic groups containing oxygen atoms is usually zero.

The F polymer (2) may be produced by using a polymerization initiator, a chain transfer agent, or the like that does not generate an atomic group containing an oxygen atom as a terminal group of the polymer chain, and has an atomic group containing an oxygen atom. The polymer may be fluorinated to produce it. Examples of the fluorination treatment method include a method using fluorine gas (see JP-A-2019-194314, etc.).

The present powder in the present invention is a powder containing an F polymer, and the amount of the F polymer in the present powder is preferably 80% by mass or more, more preferably 100% by mass.
The D50 of this powder is preferably 20 μm or less, more preferably 8 μm or less. The D50 of this powder is preferably 0.1 μm or more, more preferably 0.3 μm or more. Further, the D90 of this powder is more preferably 50 μm or less. When D50 and D90 of the present powder are within such a range, the surface area thereof becomes large, and the dispersibility of the present powder is likely to be further improved.

The powder may contain other resins or inorganic substances different from the F polymer.
Specific examples of other resins include aromatic polymers. Examples of the aromatic polymer include aromatic polyimides, aromatic polyamideimides, aromatic maleimides, aromatic elastomers such as styrene elastomers, and aromatic polyamic acids.
Specific examples of inorganic substances include silica.
This powder containing another resin or an inorganic substance preferably has a core-shell structure having an F polymer as a core and another resin or an inorganic substance as a shell. The present powder is obtained, for example, by coalescing (colliding, agglutinating, etc.) an F polymer powder with another resin or inorganic powder.

The other material in the present invention may be only the inorganic filler, only the different resins, or both the inorganic filler and the different resins.
A preferred embodiment of the inorganic filler will be described in detail in the present method (1) described later, and a preferred embodiment of the different resin will be described in detail in the present method (2) described later.

The liquid compound 1 in the present invention is a liquid having a function of dissolving, dispersing, or gelling the present powder and other materials, and when the present powder and other materials are used as a composition of the liquid compound, it is usually composed. The substance is a liquid composition, specifically, a slurry-like or gel-like composition.
In the present invention, the liquid compound 1 used for kneading and the liquid compound 2 to be mixed with the kneaded product in order to obtain a dispersion liquid may be the same or different. Both are preferably the same.

As the liquid compounds 1 and 2, one type may be used alone, or two or more types may be used in combination. The liquid compounds 1 and 2 are preferably degassed from the viewpoint of reducing the uniformity of the component distribution of the molded product and suppressing voids.
The liquid compounds 1 and 2 are preferably low-viscosity liquids or high-viscosity liquids.

The low-viscosity liquid is a liquid compound having a viscosity at 25 ° C. of more than 0 mPa · s and 10 mPa · s or less, and is preferably a liquid compound that does not react with the F polymer and the different resins.
The boiling point of the low-viscosity liquid is preferably 75 ° C. or higher, more preferably 100 ° C. or higher. The boiling point of the low-viscosity liquid is preferably 300 ° C. or lower, more preferably 250 ° C. or lower.
The low-viscosity liquid may be water or a non-aqueous dispersion medium. As the non-aqueous dispersion medium, amides, ketones or esters are preferable.

Examples of the ketone include acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl n-pentyl ketone, methyl isopentyl ketone, 2-heptanone, cyclopentanone, cyclohexanone, and cycloheptanone.
Esters include methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, ethyl 3-ethoxypropionate, γ-butyrolactone, γ- Valerolactone can be mentioned.

As amides, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-butoxy- Examples thereof include N, N-dimethylpropanamide, N, N-diethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone and the like.
Suitable specific examples of low-viscosity liquids include water, N-methyl-2-pyrrolidone, γ-butyrolactone, cyclohexanone or cyclopentanone.

The highly viscous liquid is a liquid compound having a viscosity of more than 10 mPa · s at 25 ° C., and is preferably a liquid compound that does not react with the F polymer and the different resins.
The viscosity of the highly viscous liquid is preferably 200 mPa · s or less. The boiling point of the highly viscous liquid is preferably 100 ° C. or higher. The boiling point of the highly viscous liquid is preferably 350 ° C. or lower, more preferably 300 ° C. or lower.
The highly viscous liquid is preferably glycol, glycol ether or glycol acetate, more preferably glycol monoalkyl ether, glycol monoaryl ether, glycol monoalkyl ether acetate or glycol monoaryl ether acetate, and even more preferably glycol monoalkyl ether.

Specific examples of the highly viscous liquid include 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, tripropylene glycol monobutyl ether, and propylene. Glycol monophenyl ether, diethylene glycol monoethyl ether acetate or diethylene glycol monobutyl ether acetate can be mentioned.

In the present invention, the present powder, other materials and the liquid compound 1 are kneaded to obtain the present kneaded product.
In kneading, it is preferable to knead the powder, other materials, and the liquid compound 1 so that the total mass does not substantially change, and it is preferable to knead in a closed system. That is, it is preferable to knead the liquid compound 1 so that it does not evaporate during kneading. As a result, each component is uniformly kneaded to obtain a highly defoamed main kneaded product.
For kneading, it is preferable to use a kneader equipped with a stirring tank and uniaxial or multiaxial stirring blades. The number of stirring blades is preferably two or more in order to obtain a high kneading action. The kneading method may be either a batch method or a continuous method.

The kneader used for batch kneading is preferably a Henschel mixer, a pressurized kneader, a Banbury mixer or a planetary mixer, and more preferably a planetary mixer. The planetary mixer has a biaxial stirring blade that rotates and revolves with each other, and has a structure for stirring and kneading the kneaded material in the stirring tank. Therefore, there is little dead space in the stirring tank that the stirring blades do not reach, the load on the blades is reduced, and advanced kneading becomes possible. That is, the F powder and other materials can be mixed while suppressing the aggregation of the F polymer and wetting the F powder with the liquid compound while highly interacting with each other. Further, after the kneading is completed, the dispersion medium can be added to the obtained kneaded product as it is, and the dispersion liquid can be produced as it is.
That is, the kneading in this method is preferably performed by stirring in a stirring tank having a biaxial stirring blade that rotates and revolves with each other.

Further, when the powder, the other material, and the liquid compound 1 are kneaded by heating to a predetermined temperature, the F polymer becomes sticky, so that a load is applied to the stirring blade of the kneader, and as a result, the F polymer is subjected to. Shear force tends to increase. In particular, when a plurality of stirring blades are used, a shearing force is likely to be applied to the F polymer between the stirring blades or between the stirring blades and the stirring tank. As a result, when the other material is an inorganic filler, not only the present powder and the inorganic filler are sufficiently mixed, but also the present powder or the inorganic filler is finely pulverized to form a dense present mixture. Easy to be done. Further, when the other material is a different resin, a kneaded product which can be regarded as a composite in which the powder and the different resin are highly interacted is formed, and a dense main kneaded product is likely to be formed.

The end point of kneading can be determined by the change in the monitor of the current consumption because the load applied to the stirring blade becomes smaller and the current consumption of the kneader decreases as the kneading progresses.
Further, the kneading may be controlled by using the value obtained by dividing the load current of the kneader by the shear rate of the kneader as the force and energy given to the kneaded product or the composition. Specifically, it is preferable to increase the load current from the start of kneading and gradually decrease it.

Examples of the continuous kneader include a twin-screw extrusion kneader and a millstone kneader.
The twin-screw extrusion kneader is, for example, a twin-screw continuous kneading device that kneads a kneaded product or composition by a shearing force between two screws arranged in parallel in close proximity to each other.
The stone mill type kneader is, for example, a tubular fixed portion having an internal space through which the kneaded material or the composition can pass, and a kneaded product which is arranged in the internal space of the fixed portion and passes through the internal space by rotating. It is a kneading machine having a rotating portion that conveys in the direction of the rotation axis while continuously kneading.

The kneading method includes, for example, a method of collectively kneading the present powder, other materials and the liquid compound 1, a method of mixing these to form a composition once, and a method of kneading the obtained composition, and then sequentially to the liquid compound 1. , The method of kneading while adding the present powder and other materials, and the method of sequentially adding the present powder and other materials to the liquid compound 1 and finally kneading. Further, a method of preparing a mixture of the present powder and another material in advance and kneading the mixture with the liquid compound 1, a composition of the present powder and the liquid compound 1, and a composition of the other material and the liquid compound 1. Each of these is prepared, and both compositions are mixed and kneaded.
Among these methods, a method in which the present powder, another material and the liquid compound 1 are mixed to form a composition once, and the obtained composition is kneaded is preferable, and the composition is more preferably a liquid composition. ..

The present kneaded product obtained as described above has a high viscosity and is usually a semi-solid or solid solidified product, preferably a paste or a kneaded powder. In the present specification, the paste means a solidified product having fluidity and viscosity, and the kneaded powder means a lumpy or clay-like solidified product.

The viscosity of the present kneaded product (hereinafter, also referred to as the present paste), which is a paste, is preferably 800 mPa · s or more, more preferably 1000 mPa · s or more, and further preferably 10,000 mPa · s or more. The viscosity of this paste is preferably 100,000 mPa · s or less, more preferably 80,000 mPa · s or less. The viscosity of this paste is preferably 800 to 100,000 mPa · s, more preferably 1000 to 100,000 mPa · s.

A preferred embodiment of the paste is a paste containing the powder, other materials, and a liquid compound, having a solid content of 40% by mass or more and a viscosity of 800 to 100,000 mPa · s.

In this paste containing an inorganic filler, the ratio of the powder to the inorganic filler is preferably 0.5 to 2, more preferably 0.6 to 1.5, and 0.7 to 1 with the mass of the powder being 1. Is even more preferable. In such a case, the present paste tends to have excellent dispersion stability.

In the paste containing the different resins, the mass ratio of the powder to the different resins is preferably 0.01 to 0.5 or 2 to 1000, where 1 is the mass of the powder. In this case, the present paste tends to have excellent dispersibility, and the obtained dispersion liquid tends to have excellent dispersion stability. That is, when the above ratio is within the former range, a component that can be regarded as a composite in which the powder is coated with different resins is formed, and the dispersibility of the paste is likely to be improved. Further, when the above ratio is in the latter range, the powder is highly dispersed in the different resins, and the dispersibility of the paste is likely to be improved.
The ratio in the former range is more preferably 0.05 to 0.2, still more preferably 0.08 to 0.1. The ratio in the latter range is more preferably 3 to 500 and even more preferably 5 to 100. In this case, the present paste and the obtained dispersion liquid tend to have excellent dispersion stability even when the present dispersion does not contain a surfactant.

The solid content in the present paste means the total amount of substances forming the solid content in the molded product formed from the present paste or the present dispersion. For example, when the present paste contains an F polymer and an inorganic filler and / or a different resin described later, the total content of these components is the solid content in the present paste.
The solid content in this paste is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more. The solid content is preferably 90% by mass or less, more preferably 80% by mass or less. In this case, it is easy to obtain the present dispersion liquid having excellent dispersion stability from the present paste.

In the present paste, the content of the present powder in the solid content is preferably 25% by mass or more, more preferably 30% by mass or more. The content of this powder is preferably 60% by mass or less, more preferably 50% by mass or less.
In the present paste containing the inorganic filler, the content of the inorganic filler in the solid content is preferably 10% by mass or more, more preferably 25% by mass or more. The content of the inorganic filler is preferably 75% by mass or less, more preferably 60% by mass or less.
In the present paste containing the different resins, the content of the different resins in the solid content is preferably 1% by mass or more, more preferably 5% by mass or more. The content of the different resins is preferably 20% by mass or less, more preferably 10% by mass or less.
In the paste containing both the inorganic filler and the different resins, it is preferable that at least one of the inorganic filler or the different resins is within the above range, and more preferably both are within the above range.
For example, the total amount of the powder, the inorganic filler, and the different resins in the solid content is 25% by mass or more, the inorganic filler is 25% by mass or more, or the different resins, assuming that the solid content is 100% by mass. The content is preferably 1% by mass or more, and the solid content is 100% by mass, the powder is 25% by mass or more, the inorganic filler is 25% by mass or more, and the content of the different resins is 1% by mass or more. More preferred.
Further, for example, the ratio of the present powder to the inorganic filler and the present different resin is such that the mass of the present powder is 1, the mass of the inorganic filler is 0.5 to 2, or the mass of the different resin is 0.01 to 0.5. Is preferable, the mass of the present powder is 1, the mass of the inorganic filler is 0.5 to 2, and the mass of the different resins is more preferably 0.01 to 0.5.

The solid content in the present paste means the total amount of substances forming the solid content in the molded product formed from the present paste or the present dispersion. For example, when the present paste contains an F polymer and an inorganic filler and / or a different resin described later, the total content of these components is the solid content in the present paste.
The content of the liquid compound 1 in the paste is preferably 50% by mass or less, and more preferably 40% by mass or less. The content of the liquid compound 1 in the main dough is preferably 20% by mass or more, and more preferably 25% by mass or more.

The solid content of the main kneaded product (hereinafter, also referred to as the main kneaded powder) which is the kneaded powder is preferably more than 50% by mass, more preferably 60% by mass or more. The solid content is preferably 99% by mass or less, more preferably 95% by mass or less. In this case, the main dough tends to have excellent dispersibility, and the obtained main dispersion tends to have excellent dispersion stability.
The solid content in the main kneading powder means the total amount of substances forming the solid content in the molded product formed from the main kneading powder or the main dispersion liquid. For example, when the main dough contains an F polymer and an inorganic filler and / or a different resin described later, the total content of these components is the solid content in the main dough.
When the dough contains an inorganic filler, the ratio of the powder to the inorganic filler is preferably 0.5 to 2, more preferably 0.6 to 1.5, and 0.7, with the mass of the powder as 1. To 1 is more preferable.

When the present kneaded powder contains the present different resins, the ratio of the present powder to the present different resins is preferably 0.01 to 0.5 or 2 to 1000, where the mass of the present powder is 1. In this case, the main dough tends to have excellent dispersibility, and the obtained main dispersion tends to have excellent dispersion stability. That is, when the above ratio is within the former range, a component that can be regarded as a composite in which the powder is coated with the different resins is formed, and the dispersibility of the kneaded powder is likely to be improved. Further, when the above ratio is in the latter range, the powder is highly dispersed in the different resins, and the dispersibility of the kneaded powder is likely to be improved.
The ratio in the former range is more preferably 0.05 to 0.2, still more preferably 0.08 to 0.1. The ratio in the latter range is more preferably 3 to 500 and even more preferably 5 to 100. In this case, the powder and the obtained dispersion are likely to have excellent dispersion stability even when they do not contain a surfactant.
When the dough contains both the inorganic filler and the different resins, it is preferable that at least one of the inorganic filler or the different resins is within the above range, and more preferably both are within the above range.
For example, the ratio of the powder to the inorganic filler and the different resins is such that the mass of the powder is 1 and the mass of the inorganic filler is 0.5 to 2, or the mass of the different resins is 0.001 to 0.5. It is preferably from 2 to 1000, and the mass of the present powder is 1, the mass of the inorganic filler is 0.5 to 2, and the mass of the different resins is 0.001 to 0.5. More preferably, it is 1000.

In the dough containing the inorganic filler and / or the different resins, the content of the powder in the solid content is preferably 25% by mass or more, more preferably 30% by mass or more. The content of this powder is preferably 60% by mass or less, more preferably 50% by mass or less.
In this kneaded powder, the content of the inorganic filler in the solid content is preferably 10% by mass or more, more preferably 25% by mass or more. The content of the inorganic filler is preferably 75% by mass or less, more preferably 60% by mass or less.
In the present dough, the content of the different resins in the solid content is preferably 1% by mass or more, more preferably 5% by mass or more. The content of the different resins is preferably 50% by mass or less, more preferably 20% by mass or less.
When the dough contains both the inorganic filler and the different resins, it is preferable that at least one of the inorganic filler or the different resins is within the above range, and more preferably both are within the above range.
When the main powder contains both the inorganic filler and the different resins, the total amount of the powder, the inorganic filler and the different resins in the solid content is 25% by mass or more, assuming that the solid content is 100% by mass. The inorganic filler is preferably 10% by mass or more, or the content of the different resins is preferably 1% by mass or more, and the solid content is 100% by mass, the powder is 25% by mass or more, and the inorganic filler is 10% by mass or more. Moreover, the content of the different resins is more preferably 1% by mass or more.

The content of the liquid compound 1 in the main dough is preferably 50% by mass or less, and more preferably 40% by mass or less. The content of the liquid compound 1 in the main dough is preferably 20% by mass or more, and more preferably 25% by mass or more.
The viscosity of this kneaded powder is from 10000 when the viscosity is measured by a capillograph (temperature: 25 ° C., shear rate: 1 / sec, capillary length: 10 mm, capillary radius: 1 mm, furnace body diameter: 9.55 mm, load cell capacity: 2 t). It is preferably 100,000 Pa · s. In particular, when the viscosity of the main dough having a solid content of 60 to 70% by mass is in such a range, the dispersibility when mixing it with the liquid compound 2 and the dispersion stability of the obtained main dispersion are particularly improved. It's easy to do. The main kneading powder having such a viscosity can be produced by controlling the kneading time and the shearing force in kneading. Specifically, it can be produced by lengthening the kneading time and increasing the shearing force.

When the main kneaded product is mixed with the liquid compound 2, the main dispersion liquid is obtained, and when the main paste or the main kneaded powder and the liquid compound 2 are mixed as the main kneaded product, the main dispersion liquid is obtained more efficiently.
The mixing of the kneaded product and the liquid compound 2 in the present invention is an ultrasonic homogenized baint shaker, a ball mill, an attritor, a basket mill, a sand mill, and a sand grinder from the viewpoint of the dispersibility and dispersion stability of the obtained dispersion. , Dyno Mill, Dispermat, SC Mill, Spike Mill, Agitator Mill, and other media-free dispersers, ultrasonic homogenizers, nanomizers, resolvers, dispersers, high-speed impeller dispersers, and other media-free dispersers. Preferably, it is more preferable to use a disperser using media.

Further, when mixing using a collision type disperser, the dispersion stability of the present dispersion is improved, so it is preferable to use a collision type disperser. The collision type disperser is a disperser in which a pressurized liquid compound 2 is made to collide with the present paste and dispersed by the impact force or the like.
As the disperser, either a disperser that pressurizes and collides with the paste and the liquid compound 2 or a disperser that collides the liquid compound 2 with pressure on the paste may be used.
Examples of the former disperser include a nanomizer, Genus PY, an ultimateizer, Aqua, and a microfluidizer, and examples of the latter disperser include a homogenizer.

Further, as a method of mixing the main kneaded product and the liquid compound 2, following the kneading when preparing the main kneaded product, the main kneaded product and the liquid compound are mixed in a kneading machine having a stirring tank and a stirring blade used for the kneading. Examples thereof include a method of mixing with 2 and a method of taking out the main kneaded product from the kneading machine used for kneading and mixing the main kneaded product with the liquid compound 2 by another kneading machine. Examples of the kneader include batch type and continuous type kneaders similar to the above.

The viscosity of the dispersion is preferably 50 mPa · s or more, more preferably 75 mPa · s or more, and even more preferably 100 mPa · s or more. The viscosity of the dispersion is preferably less than 10,000 mPa · s, more preferably 5000 mPa · s or less, and even more preferably 1000 mPa · s or less.
The thixotropy ratio of the present dispersion is preferably 1 to 10, and more preferably 1 to 7. This dispersion having such a thixotropy ratio is excellent in coatability and homogeneity. The thixotropy is calculated by dividing the viscosity of the dispersion liquid measured under the condition of a rotation speed of 30 rpm by the viscosity of the main dispersion liquid measured under the condition of a rotation speed of 60 rpm.

From the viewpoint of reducing the uniformity of the component distribution of the molded product obtained from the present dispersion and suppressing voids, the foam volume ratio in the present dispersion is preferably less than 10%, more preferably less than 5%. The foam volume ratio is preferably 0% or more.
Incidentally, the foam volume ratio measures the standard atmospheric pressure and 20 of the dispersion at ℃ volume _{(V N),} it was combined foam when the pressure was reduced to 0.003MPa volume and _{(V V),} below It is a value obtained by the calculation formula of.
Foam volume ratio _{[%] = 100 × (V} V -V N) / V N

As a preferred first aspect of the present invention (hereinafter, also referred to as the present method (1)), the present powder, the inorganic filler and the liquid compound 1 are kneaded to form the present kneaded product (hereinafter, also referred to as the present kneaded product 1). Then, an embodiment in which the kneaded product 1 and the liquid compound 2 are mixed to obtain the present dispersion liquid (hereinafter, also referred to as the present dispersion liquid 1) can be mentioned.
The kneading method includes, for example, a method of kneading the present powder, the inorganic filler and the liquid compound 1 all at once, a method of mixing these to form a composition once, and a method of kneading the obtained composition, and then sequentially to the liquid compound 1. Examples thereof include a method of kneading while adding the present powder and the inorganic filler, and a method of sequentially adding the present powder and the inorganic filler to the liquid compound 1 and finally kneading. Further, a method of preparing a mixture of the present powder and the inorganic filler in advance and kneading the mixture with the liquid compound 1, a composition of the present powder and the liquid compound 1, and a composition of the inorganic filler and the liquid compound 1, respectively. Examples thereof include a method of preparing, mixing both compositions, and kneading.
The composition in the present method (1) is preferably a liquid composition. Further, the main kneaded product 1 in the present method (1) may be a paste (hereinafter, also referred to as the main paste 1) or a kneaded powder (hereinafter, also referred to as the main kneaded powder 1).
Among these methods, the powder, the inorganic filler and the liquid compound 1 are mixed to form a composition once, and the obtained composition is kneaded to obtain the kneaded product 1 to obtain the kneaded product 1 and the liquid compound 2. Is preferred to obtain the present dispersion 1.

The inorganic filler in the method (1) is used to improve the physical characteristics of the obtained molded product when the dispersion liquid 1 is used for forming various molded products, and the type thereof depends on the purpose of the molded product. Is selected as appropriate.
For example, for the purpose of improving the dielectric constant of a molded product, an inorganic filler having a high dielectric constant is used. The high dielectric constant inorganic filler means a filler having a dielectric constant at 25 ° C. of 10 or more, preferably 25 or more, and more preferably 50 or more.
As such an inorganic filler, a perovskite type ferroelectric filler or a bismuth layered perovskite type ferroelectric filler is preferable.
Examples of the perovskite-type ferroelectric substance include barium titanate, lead zirconate titanate, lead titanate, zirconium oxide, and titanium oxide. On the other hand, examples of the bismuth layered perovskite type ferroelectric substance include bismuth strontium tantalate, bismuth strontium niobate, and bismuth titanate.

For example, for the purpose of reducing the dielectric constant and dielectric loss tangent of the molded product, or the coefficient of linear expansion, an inorganic filler having a low dielectric constant and low dielectric loss tangent or a low coefficient of linear expansion is used.
As such an inorganic filler, a boron nitride filler, a beryllium oxide filler (berilia filler), a silicon oxide filler (silica filler), a wollastonite filler, or a magnesium metasilicate filler (steatite filler) is preferable.

For example, a metal oxide filler is used for the purpose of improving the thermal conductivity or scratch resistance of the molded product.
The metal oxide is selected from the group consisting of aluminum oxide, lead oxide, iron oxide, tin oxide, magnesium oxide, titanium oxide, zinc oxide, antimony trioxide, zirconium oxide, lanthanum oxide, neodium oxide, cerium oxide and niobium oxide. At least one of the above is preferable, and aluminum oxide is more preferable. These metal oxides (particularly, alumnium oxide) are also preferable in terms of high thermal conductivity and Mohs hardness.

Further, as the inorganic filler other than these, a glass fiber filler or a carbon filler may be used.
Examples of the carbon filler include a garbon filler containing at least one selected from the group consisting of carbon fiber (carbon fiber), carbon black, graphene, graphene oxide, fullerene, graphite, and graphite oxide. Examples of carbon fibers include polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, vapor-grown carbon fibers, and carbon nanotubes (single-wall, double-wall, multi-wall, cup-laminated type, etc.).

From the viewpoint of dispersibility of the dispersion liquid 1, the inorganic filler is preferably a boron nitride filler, a silica filler or a magnesium metasilicate filler, more preferably a silica filler or a boron nitride filler, and even more preferably a silica filler. These fillers may be fired ceramic fillers.
The inorganic filler is preferably a filler containing silicon oxide or magnesium metasilicate. The content of silicon oxide or magnesium metasilicate in this inorganic filler is preferably 50% by mass or more, more preferably 75% by mass. The content of silicon oxide or magnesium metasilicate is preferably 100% by mass or less, more preferably 90% by mass or less.

The shape of the inorganic filler is appropriately selected according to the intended purpose, and may be in the form of particles or fibers. If a particulate filler is used, the surface flatness of the molded product is improved, the slidability of the surface is improved, and the scratch resistance is likely to be improved. On the other hand, if a fibrous inorganic filler is used, a part of the filler particles is exposed on the surface of the molded product, and for example, it is easy to improve the abrasion resistance and the scratch resistance of the product surface.
Specific shapes of the inorganic filler include spherical, scaly, layered, leafy, apricot kernel, columnar, chicken crown, equiaxed, leafy, mica, block, flat plate, wedge, rosette, and mesh. It may be spherical or prismatic, preferably spherical or scaly.
In the case of a particulate inorganic filler, the average particle size of D50 is preferably 0.02 to 200 μm, more preferably 0.1 to 20 μm, and even more preferably 1 to 10 μm. Further, in the case of a fibrous inorganic filler, the average fiber length thereof is preferably 0.05 to 300 μm. The average fiber diameter of the fibrous inorganic filler is preferably 0.01 to 15 μm.

Further, the inorganic filler may have various shapes such as a hollow shape and a honeycomb shape in addition to the above shape, but from the viewpoint of improving the low dielectric property and the low dielectric loss tangent property of the molded product, the hollow shape is formed. It is preferable to have the shape of.
The hollow ratio, which is the average value of the volume ratio of the voids per particle of the hollow inorganic filler, is preferably 40 to 80%.
The particle strength of the hollow inorganic filler is preferably 20 MPa or more. The particle strength is the particle strength when the residual ratio of the hollow inorganic filler when pressure-pressed is 50%. The particle strength can be calculated from the apparent density of the hollow inorganic filler and the apparent density of the pellets obtained by press-pressing the medium spherical inorganic filler.

It is preferable that at least a part of the surface of the inorganic filler is surface-treated. Examples of the surface treatment agent used for such surface treatment include polyhydric alcohols such as trimethylolethane, pentaeristol and propylene glycol, saturated fatty acids such as stearic acid and lauric acid, and esters thereof, alkanolamines, trimethylamines and triethylamines. Examples include amines, paraffin waxes, silane coupling agents, silicones and polysiloxanes.

The inorganic filler is preferably an inorganic filler surface-treated with a silane coupling agent. Such an inorganic filler has an excellent affinity with the present powder and easily improves the dispersibility of the present dispersion. Further, in the melt firing of the F polymer when forming a molded product from the present dispersion liquid containing the same, the flow of the inorganic filler is promoted by thermal decomposition to generate gas, and the uniformity of the molded product is likely to be improved. it is conceivable that.
The silane coupling agent is preferably a silane coupling agent having a functional group, 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3 -Methacryloxypropyltriethoxysilane or 3-isocyanuppropyltriethoxysilane is more preferred.

As the inorganic filler, one kind of inorganic filler may be used alone, or two or more kinds of inorganic fillers may be used in combination. In the latter case, it is preferable to use at least a silica filler, and it is more preferable to use two kinds of silica fillers. Further, in the latter case, it is preferable to use a hollow inorganic filler and a non-hollow inorganic filler in combination.

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

In the present method (1), the content of the liquid compound 1 in the kneaded product 1 is preferably 10% by mass or more. The content of the liquid compound 1 is preferably 60% by mass or less, more preferably 25% by mass or less. In this case, the kneading proceeds while the powder is always in a wet state, and the powder, the inorganic filler and the liquid compound 1 are uniformly mixed, and the highly degassed main kneaded product 1 can be easily obtained.

The solid content in the kneaded product 1 contains the above powder and the inorganic filler. The solid content of the kneaded product 1 also includes substances other than the powder and the inorganic filler that form the solid content in the molded product formed from the dispersion liquid 1.
When the main paste 1 is the main paste 1, from the viewpoint that the main paste 1 having excellent dispersibility can be easily obtained by kneading, the total mass of the main paste 1 is 100% by mass, and the solid content is 40% by mass or more. It is preferable, and more preferably 50% by mass or more. Further, from the viewpoint of dispersibility of the dispersion liquid 1, the solid content is preferably 90% by mass or less, more preferably 75% by mass or less.
The solid content may contain non-volatile components other than the present powder and the inorganic filler, and the total amount of the present powder and the inorganic filler in the solid content is 80% by mass or more, assuming that the total mass of the solid content is 100% by mass. Is preferable, and 90% by mass or more is more preferable. The total amount is preferably 100% by mass or less.

In the present method (1), the ratio of the present powder to the inorganic filler in the kneaded product 1 is preferably 0.5 to 2 with the mass of the present powder being 1.
The amount of the present powder in the solid content is preferably 25% by mass or more, more preferably 30% by mass or more, with the solid content as 100% by mass. The amount of this powder is preferably 50% by mass or less, more preferably 40% by mass or less.
Apart from the above ratio, from the viewpoint of the electrical characteristics of the molded product formed from the dispersion liquid 1, the amount of the inorganic filler in the solid content of the kneaded product 1 is 25% by mass or more, assuming that the solid content is 100% by mass. Preferably, 50% by mass or more is more preferable, and 60% by mass or more is further preferable. The amount of the inorganic filler is preferably 75% by mass or less, more preferably 60% by mass or less.

In the present method (1), when the composition 1 is kneaded to obtain the main kneaded product 1, the composition 1 can be prepared by mixing the present powder, the inorganic filler, and the liquid compound 1.
Examples of the mixing method include a method of collectively mixing the present powder, the inorganic filler and the liquid compound 1, and a method of mixing the present powder, the inorganic filler and the liquid compound 1 while sequentially adding them.
Specific methods for mixing include, for example, a method in which the powder and the inorganic filler are collectively added to the liquid compound 1 and mixed, and a method in which the powder and the inorganic filler are sequentially added to the liquid compound 1 and mixed. The method of mixing the present powder and the inorganic filler in advance, and the method of mixing the obtained mixture and the liquid compound 1 in advance, the present powder and the liquid compound 1 in advance, and the inorganic filler and the liquid compound 1 respectively. Examples thereof include a method of further mixing the obtained two kinds of mixtures.
Among these methods, from the viewpoint of dispersibility of the composition 1, a method in which the powder and the inorganic filler are mixed in advance and the obtained mixture and the liquid compound 1 are mixed is preferable.

The kneaded product 1 in the present method (1) may contain components other than the present powder, the inorganic filler and the liquid compound 1. Such a component may be a component that forms a solid content in the molded product formed from the present dispersion liquid 1, or may be a component that does not form a solid content. Examples of such a component include a resin different from the F polymer. Examples of the different resin include the same resin as the present different resin in the present method (2), which will be described later, and an aromatic polymer is preferable from the viewpoint of improving the adhesiveness and low linear expansion property of the molded product.
When such a component is a component forming a solid content, the amount of such a component contained in the solid content in the present kneaded product 1 is preferably 20% by mass or less, more preferably 10% by mass or less.

As the aromatic polymer, aromatic elastomers such as aromatic polyimides, aromatic maleimides and styrene-based elastomers or aromatic polyamic acids are preferable, and aromatics such as aromatic polyimides, aromatic maleimides, polyphenylene ethers and styrene-based elastomers are preferable. Elastomers are more preferred, and aromatic polyimides or aromatic polyamic acids are even more preferred. The aromatic polyimide may be thermoplastic or thermosetting. The thermoplastic polyimide means a polyimide that has been imidized and does not undergo a further imidization reaction.
When the main kneaded product 1 in the present method (1) contains a different resin, the main kneaded product 1 mixes the present powder and the inorganic filler, and the obtained mixture, the liquid compound 1 and a different resin are mixed. It is preferable to prepare the composition 1 and knead the composition 1 to obtain the composition 1.

In the present method (1), it is preferable to knead the composition 1 to obtain the main kneaded product 1. The main kneaded product 1 in the present method (1) is preferably the main paste 1 or the main kneaded powder 1.
The kneaded product 1 in the present method (1) preferably contains a surfactant from the viewpoint of improving the dispersion stability and handleability of the dispersion liquid. The present paste containing the surfactant may be prepared by kneading the powder, the inorganic filler, the liquid compound 1 and the surfactant all at once, or kneading the composition 1 containing the surfactant. Alternatively, the composition 1 containing no surfactant may be kneaded, and then a surfactant may be added and kneaded to prepare the composition.

Examples of the surfactant include anionic, cationic and nonionic surfactants, and nonionic surfactants are preferable.
The hydrophilic moiety of the surfactant preferably has an oxyalkylene group or an alcoholic hydroxyl group.
The oxyalkylene group may be composed of one kind or two or more kinds. In the latter case, different types of oxyalkylene groups may be arranged in a random manner or in a block shape.
The oxyalkylene group is preferably an oxyethylene group.

The hydrophobic moiety of the surfactant preferably has an acetylene group, a polysiloxane group, a perfluoroalkyl group or a perfluoroalkenyl group. In other words, the surfactant is preferably an acetylene-based surfactant, a silicone-based surfactant or a fluorine-based surfactant, and more preferably a silicone-based surfactant.
As the fluorine-based surfactant, a fluorine-based surfactant having a hydroxyl group, particularly an alcoholic hydroxyl group or an oxyalkylene group, and a perfluoroalkyl group or a perfluoroalkenyl group is preferable.

Specific examples of surfactants include the "Futergent" series (Futergent manufactured by Neos Co., Ltd. is a registered trademark), the "Surflon" series (Surflon manufactured by AGC Seimi Chemical Co., Ltd. is a registered trademark), and the "Mega Fuck" series (DIC). Megafuck Co., Ltd. is a registered trademark), "Unidyne" series (Unidyne manufactured by Daikin Kogyo Co., Ltd. is a registered trademark), "BYK-347", "BYK-349", "BYK-378", "BYK-3450", Examples thereof include "BYK-3451", "BYK-3455", "BYK-3456" (manufactured by BIC Chemie Japan Co., Ltd.), "KF-6011", and "KF-6043" (manufactured by Shin-Etsu Chemical Industry Co., Ltd.).
When the main kneaded product 1 contains a surfactant, the content in the main kneaded product 1 is preferably 1 to 15% by mass. In this case, the affinity between the components is increased, and the dispersion stability of the present dispersion 1 is likely to be further improved.

As a preferred second aspect of this method (hereinafter, also referred to as this method (2)), the present powder, the present different resin and the liquid compound 1 are kneaded and kneaded (hereinafter, also referred to as the present kneaded product 2). Then, an embodiment in which the kneaded product 2 and the liquid compound 2 are mixed to obtain a dispersion liquid (hereinafter, also referred to as the main dispersion liquid 2) can be mentioned.
The method for obtaining the kneaded product 2 is, for example, a method of kneading the powder, the different resins and the liquid compound 1 in a batch, a method of mixing these to form a composition once, and a method of kneading the obtained composition, a liquid. Examples thereof include a method of sequentially adding the present powder and the present different resins to the compound 1 and kneading, and a method of sequentially adding the present powder and the inorganic filler to the liquid compound 1 and finally kneading. Further, a method of preparing a master batch of the powder and the different resin in advance and kneading it with the liquid compound 1, a composition of the powder and the liquid compound 1, and a composition of the different resin and the liquid compound 1. Examples thereof include a method of preparing each compound, mixing both compositions, and kneading them.
The composition in the present method (2) is preferably a liquid composition. Further, the main kneaded product 2 in the present method (2) may be a paste (hereinafter, also referred to as the main paste 2) or a kneaded powder (hereinafter, also referred to as the main kneaded powder 2).
Among these methods, the powder, the different resin, and the liquid compound 1 are mixed to form a composition (hereinafter, also referred to as composition 2), and the obtained composition 2 is kneaded to obtain the kneaded product 2. A method of obtaining the present dispersion 2 by mixing the present kneaded product 2 and the liquid compound 2 is preferable.

The different resin in the present method (2) is a resin different from the F polymer and does not contain TFE units. The different resins may be thermosetting resins or thermoplastic resins.
Examples of the different resins include aromatic polyester, aromatic polyimide, aromatic polyamic acid, aromatic polyamideimide, epoxy resin, maleimide resin, urethane resin, thermoplastic elastomer, non-aromatic polyamideimide, polyphenylene ether, polyphenylene oxide, and liquid crystal. Examples thereof include polyester, polysaccharides, nylon, acrylic resin, methacrylic resin, butyral, cyanate ester resin, ABR rubber, cellulose, PVA acrylic methacryl, polyalkylene ether, polyoxyethylene alkyl ether, and fluoropolymers other than F polymer.

The different resins are preferably aromatic polyesters, aromatic polyimides, aromatic polyamic acids, aromatic polyamideimides, polyphenylene ethers, epoxy resins, maleimide resins or thermoplastic elastomers. The aromatic polyimide may be thermoplastic or thermosetting. Further, the different resins are preferably aromatic polymers.
Specific examples of aromatic polyimides include "Neoprim (registered trademark)" series (manufactured by Mitsubishi Gas Chemical Company), "Spixeria (registered trademark)" series (manufactured by Somar), and "Q-PILON (registered trademark)" series ( PI Technology Research Institute), "WINGO" series (Wingo Technology), "Toimide (registered trademark)" series (T & K TOKA), "KPI-MX" series (Kawamura Sangyo), "Yupia (Yupia) Registered trademark) -AT "series (manufactured by Ube Industries, Ltd.) can be mentioned.
Specific examples of the aromatic polyamide-imide include "HPC-1000" and "HPC-2100D" (manufactured by Showa Denko Materials Co., Ltd.).

The urethane resin may be, for example, urethane fine particles containing an acrylic component, or a homopolymer or a copolymer. Specific examples thereof include commercially available dimic beads CM (manufactured by Dainichiseika Kogyo Co., Ltd.), art pearl (manufactured by Negami Kogyo Co., Ltd.), and grand pearl (manufactured by Aica Kogyo Co., Ltd.).

Polysaccharides include xanthan gum, guar gum, casein, arabic gum, gelatin, amylose, agarose, agaropectin, arabinan, curdlan, callose, carboxymethyl starch, chitin, chitosan, quince seed, glucomannan, gellan gum, tamarin seed gum, dextran. , Nigeran, hyaluronic acid, starchulan, funoran, pectin, porphyran, laminarin, likenan, carrageenan, alginic acid, polysaccharide gum, alkathy gum, locust bean gum and the like.

Examples of the acrylic resin or methacrylic resin include polyacrylic acid, polymethacrylic acid, ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, and ethylene-. Examples include vinyl acetate copolymers.
Examples of the acrylic resin or methacrylic resin include the Neocryl series manufactured by Kusumoto Kasei Co., Ltd. as a commercially available product.

Nylons include ε-caprolactam (nylon 6), undecanlactam (nylon 11), lauryllactam (nylon 12), aminocaproic acid, enantractum, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α. -Polymers such as pyrrolidone, α-piperidone; diamines such as hexamethylenediamine, nonanediamine, nonanemethylenediamine, methylpentadiamine, undecamethylenediamine, dodecamethylenediamine, metaxylenediamine, and adibic acid, sebacic acid, terephthalic acid. , Isophthalic acid, dodecandicarboxylic acid, a copolymer obtained by copolymerizing with a carboxylic acid compound such as a dicarboxylic acid such as glutaric acid, or at least one of these polymers or a mixture of the copolymers. Be done.

Examples of the butyral resin include Sekisui Chemical's Eslek (registered trademark) B series, K (KS) series, SV series, and Kuraray's Mobital (registered trademark) series.

Examples of the cyanate ester resin include a resin composed of at least a bifunctional aliphatic cyanate ester, at least a bifunctional aromatic cyanate ester, or a mixture thereof.
Specific examples of the cyanate ester resin include 1,3,5-trisianatobenzene, 1,3-disyanatonaphthalene, 1,4-disyanatonaphthalene, 1,6-disyanatonaphthalene, and 1,8-. A polymer of at least one polyfunctional cyanate ester selected from the group consisting of disianatonaphthalene, 2,6-disianatonaphthalene, and 2,7-disianatonaphthalene, bisphenol A type cyanate ester resin, or the like. Hydrogenated hydrogenated product, bisphenol F type cyanate ester resin or hydrogenated hydrogenated product, 6F bisphenol A dicyanic acid ester resin, bisphenol E type dicyanic acid ester resin, tetramethylbisphenol F dicyanic acid ester resin , Bisphenol M bisphenol ester resin, dicyclopentadiene bisphenol dicyanic acid ester resin, or at least one citrate novolak resin.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthylene ether type epoxy resin, and glycidylamine type epoxy. Resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanedimethanol type epoxy resin, trimethylol type epoxy resin , Halogenized epoxy resin and the like.

The thermoplastic elastomer is an elastomer that plasticizes when heated, and is, for example, an olefin-based elastomer, a styrene-based elastomer, a vinyl chloride-based thermoplastic elastomer, a urethane-based elastomer, a polyamide-based elastomer, a polyester-based elastomer, or a polybutadiene-based elastomer. Examples thereof include acrylic elastomers and silicone elastomers.
Examples of the olefin-based elastomer include an olefin-based elastomer in which an olefin-based rubber is finely dispersed in a matrix of an olefin-based resin such as PP.
Examples of the styrene-based elastomer include styrene-butadiene copolymer, hydrogenated-styrene-butadiene copolymer, hydrogenated-styrene-isoprene copolymer, styrene-butadiene-styrene block copolymer, and styrene-isoprene-styrene block. Examples thereof include a polymer, a hydrogenated product of a styrene-butadiene-styrene block copolymer, and a hydrogenated product of a styrene-isoprene-styrene block copolymer.
Examples of the polyester-based elastomer include a polyester-polyester copolymer, a polyurethane-polyester / polyester copolymer, and a nylon-polyester / polyester copolymer.

The commercially available products include TR series (styrene / butadiene thermoplastic elastomer, manufactured by JSR Co., Ltd.), RB series (polybutadiene-based thermoplastic elastomer, manufactured by JSR Co., Ltd.), JSR EXELINK (olefin-based thermoplastic elastomer, manufactured by JSR Co., Ltd.). ), DYNARON (registered trademark) series (hydrogenated thermoplastic elastomer, manufactured by JSR Co., Ltd.), Thermolan (registered trademark) (olefin-based thermoplastic elastomer, manufactured by Mitsubishi Chemical Corporation), Epox TPE series (olefin-based thermoplastic elastomer, Sumitomo Chemical Co., Ltd.), Septon (registered trademark) series (hydrogenated styrene-based thermoplastic elastomer, manufactured by Kuraray Co., Ltd.), Tough Tech (registered trademark) (hydrogenized styrene-based thermoplastic elastomer, manufactured by Asahi Kasei Co., Ltd.). ..
Examples of the fluoropolymer other than the F polymer include polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene and the like.

As the present different resin, an aqueous dispersion such as a vinyl resin, a thermoplastic resin, a curable resin, a thermoplastic block copolymer, and an elastomer, which are binder resins, may be used.
Examples of the vinyl resin include aqueous dispersions of vinyl acetate resin, acrylic resin, styrene resin and the like.
Examples of the thermoplastic resin include aqueous dispersions of polyolefin resins, ethylene-vinyl acetate copolymers, polyamide resins and the like.
Examples of the curable resin include aqueous dispersions of epoxy resin, urethane resin, polyimide resin, unsaturated polyester resin and the like. The curable resin may be any of a room temperature curable resin, a thermosetting resin, and a photocurable resin.

The different resins may be compounds that are polymerized or crosslinked by external energy such as heat or light to become the resin, or may consist of a monomer of the resin, a reactant of the monomer, or a curing agent.
Such embodiments include a combination of isocyanate and diol in a urethane resin, a combination of a copolymer of bisphenol A and epichlorohydrin in an epoxy resin, and a curing agent such as polyamine or acid anhydride, and a cyanate ester resin. Cyanic acid ester can be mentioned.
These aspects are appropriately determined from the monomers based on the above-mentioned different resins selected for the purpose of being contained in the dispersion liquid 2. For example, in the case of cyanate ester, the above-mentioned cyanate ester can be mentioned. In the case of an epoxy resin, a copolymer that gives the above-mentioned epoxy resin can be mentioned. Further, the resin component in these embodiments does not need to be completely polymerized or crosslinked, and may be partially unpolymerized or uncrosslinked.

The kneaded product 2 in the present method (2) may further contain an inorganic filler. The definition and scope of the inorganic filler in the present method (2) are the same as those of the inorganic filler in the present method (1), including preferred embodiments. When the kneaded product 2 contains an inorganic filler, the viewpoint of the dispersion stability of the main kneaded product 2 and the main dispersion liquid 2, and the viewpoints of low dielectric adjacency and low linear expansion of the molded product molded from the main dispersion liquid 2. Therefore, the amount of the inorganic filler in the kneaded product 2 is preferably 1 to 50% by mass.
The content of the liquid compound 1 in the kneaded product 2 in the present method (2) is preferably 10% by mass or more. The content of the liquid compound 1 is preferably 60% by mass or less, more preferably 25% by mass or less. As a result, the kneading proceeds while the powder and the different resins are always maintained in a semi-dissolved or swollen state, and the powder, the different resins and the liquid compound 1 are uniformly mixed.

The solid content in the kneaded product 2 contains the above powder, the F polymer, and a different resin. The solid content of the kneaded product 2 also includes substances other than the powder and the different resins that form the solid content in the molded product formed from the dispersion liquid 2, such as the inorganic filler.
From the viewpoint that the present paste 2 having excellent dispersibility can be easily obtained by kneading, the total mass of the main kneaded product 2 is 100% by mass, and the solid content is preferably 40% by mass or more, more preferably 50% by mass or more. Further, from the viewpoint of dispersibility of the present dispersion, the solid content is preferably 90% by mass or less, more preferably 75% by mass or less.
The solid content may contain non-volatile components other than the present powder and the present different resin, and the total amount of the present powder and the present different resin in the solid content is 60 mass with 100% by mass of the total mass of the solid content. % Or more is preferable, and 70% by mass or more is more preferable. The total amount is preferably 100% by mass or less.

In the present method (2), the mass ratio of the present powder to the present different resin in the present kneaded product 2 is whether the mass of the present different resin is 0.01 to 0.5, where the mass of the present powder is 1. It is preferably 2 to 1000. In this case, the kneaded product 2 tends to have excellent dispersibility, and the obtained dispersion liquid 2 tends to have excellent dispersion stability. That is, when the above ratio is within the former range, a component that can be regarded as a composite in which the powder is coated with different resins is formed, and the dispersibility of the paste 2 is likely to be improved. Further, when the above ratio is in the latter range, the powder is highly dispersed in the different resins, and the dispersibility of the paste 2 is likely to be improved.
The ratio in the former range is more preferably 0.005 to 0.2 and even more preferably 0.01 to 0.1. The ratio in the latter range is more preferably 3 to 500 and even more preferably 5 to 100. In this case, the kneaded product 2 and the obtained dispersion liquid 2 tend to have excellent dispersion stability even when they do not contain a surfactant.

In addition to the above ratio, from the viewpoint of dispersion stability of the kneaded product 2 and the dispersion liquid 2 and low dielectric loss tangent property of the molded product formed from the dispersion liquid 2, the solid content in the kneaded product 2 The amount of the present powder is preferably 25% by mass or more, more preferably 50% by mass or more, with the solid content as 100% by mass. The amount of this powder is preferably 99% by mass or less, more preferably 90% by mass or less.
The amount of the different resins in the solid content is preferably 1% by mass or more, more preferably 5% by mass or more, with the solid content as 100% by mass. The amount of the different resins is preferably 30% by mass or less, more preferably 20% by mass or less.
It is more preferable that the amount of the present powder in the solid content is 25% by mass or more and the amount of the different resins is 1% by mass or more, assuming that the solid content is 100% by mass.

In the present method (2), when the composition 2 is kneaded to obtain the main kneaded product 2, the composition 2 can be prepared by mixing the present powder with a different resin and the liquid compound 1.
Examples of the mixing method include a method of collectively mixing the powder, the different resin and the liquid compound 1, and a method of sequentially adding the powder, the different resin and the liquid compound 1 and mixing them.

Specific methods for mixing include, for example, a method in which the powder and the different resins are collectively added to the liquid compound 1 and mixed, and the powder and the different resins are sequentially added to the liquid compound 1. A method of mixing the powder and the different resin in advance, and a method of mixing the obtained mixture and the liquid compound 1 in advance, the powder and the liquid compound 1 in advance, and the different resin and the liquid compound 1 in advance. Examples thereof include a method of mixing each of them and further mixing the obtained two kinds of mixtures.
Among the above mixing methods, from the viewpoint of dispersibility of the composition, a method in which the different resin and the liquid compound 1 are mixed in advance and the obtained mixture and the present powder are mixed is preferable.

In the present method (2), it is preferable to knead the composition 2 to obtain the main kneaded product 2. The main kneaded product 2 in the present method (2) is preferably the main paste 2 or the main kneaded powder 2.
The paste 2 preferably contains a surfactant. Examples of the surfactant include the same surfactants as those in the above-mentioned method (1).
When the present paste 2 contains a surfactant, the content of the surfactant in the present paste 2 is preferably 1 to 15% by mass. In this case, the affinity between the components is increased, and the dispersion stability of the present dispersion 2 is likely to be further improved.

The present paste 2 containing the surfactant may be prepared by kneading the composition containing the present powder, the present different resin and the surfactant, or the composition containing the present powder, the present different resin and the liquid compound 1. May be prepared by kneading, and then adding a surfactant and kneading to prepare. The composition containing the present powder, the surfactant and the liquid compound 1 is kneaded, and further, the present different resin is added and kneaded to prepare. However, it is preferable to knead the composition containing the present powder, the present different resin and the liquid compound 1, and further add a surfactant and knead to prepare the composition.
In this case, the powder is likely to be sheared when the composition is kneaded, the viscosity of the paste 2 is lowered, and the dispersion stability of the obtained dispersion liquid 2 is more likely to be improved.
As a method for obtaining the dispersion liquid 2 containing the different resin, the surfactant and the inorganic filler, a mixture of the inorganic filler and the powder, the liquid compound 1 and the different resin are kneaded and kneaded. The method is preferable in which the kneaded product and the surfactant are kneaded to obtain the present paste 2 and the present paste 2 and the liquid compound 2 are mixed.

When the dispersion contains both the inorganic filler and the different resin as other materials, the method kneads the mixture containing the powder and the inorganic filler with the mixture containing the different resin and the liquid compound 1. The present kneaded product may be obtained, and the present kneaded product and the liquid compound 2 may be mixed to obtain the present dispersion liquid. The mixture containing the present powder and the inorganic filler is preferably in the form of powder. According to such an embodiment, not only the dispersion stability of the kneaded product and the obtained dispersion liquid is improved, but also the storage stability of the dispersion liquid when it is stored for a long period of time is likely to be improved. When the dispersion liquid is allowed to stand at 25 ° C. for 30 days, the fluctuation range of the thixotropy ratio is preferably 3 or less and preferably less than 1 as an absolute value.
The kneaded product or the dispersion liquid in such an embodiment preferably does not contain a surfactant. Even when a surfactant is not contained, the present paste and the obtained dispersion liquid tend to have excellent dispersion stability, and it is easy to obtain a molded product having excellent electrical characteristics. These effects tend to be particularly remarkable when the main kneaded product is the main kneaded powder.

When this dispersion is applied to the surface of a base material and heated to form a layer made of an F polymer (hereinafter, also referred to as an F layer), a laminate having the base material and the F layer can be produced.
In the production of the above-mentioned laminate, the F layer may be formed on at least one side of the surface of the base material, the F layer may be formed on only one side of the base material, and the F layer is formed on both sides of the base material. You may.
The surface of the base material may be surface-treated with a silane coupling agent or the like.
When applying this dispersion, the 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 , The application method of the slot die coating method can be used.

The F layer is preferably formed by removing the liquid compound 1 and the liquid compound 2 (hereinafter, also collectively referred to as liquid compounds) by heating, and then firing the F polymer by heating.
The temperature for removing the liquid compound is preferably as low as possible, and is preferably 50 to 150 ° C. lower than the lower boiling point of the boiling point of the liquid compound 1 and the boiling point of the liquid compound 2. For example, when N-methyl-2-pyrrolidone having a boiling point of about 200 ° C. is used as the liquid compounds 1 and 2, it is preferable to heat the dispersion at 150 ° C. or lower, preferably 100 to 120 ° C. It is preferable to blow air in the step of removing the liquid compound.
After removing the liquid compound, it is preferable to heat the base material to a temperature range in which the F polymer is fired to form the F layer. For example, it is preferable to fire the F polymer in the range of 300 to 400 ° C. That is, the F layer preferably contains a fired product of the F polymer.

As described above, the F layer is formed through the steps of coating, drying, and firing the dispersion liquid. Each of these steps may be performed once or twice or more.
For example, in the F layer, the step of applying the above dispersion liquid to the surface of the base material, removing the liquid compound by heating to form a film is repeated twice, and the film having an increased thickness is heated to heat the F polymer. May be formed by firing.
From the viewpoint of easily obtaining a thick F layer having excellent smoothness, it is preferable to carry out the steps of applying and drying the dispersion liquid twice.
The thickness of the F layer is preferably 0.1 μm or more, and more preferably 1 μm or more. The upper limit of the thickness is 200 μm. In this range, the F layer having excellent crack resistance can be easily formed.

The peel strength between the F layer and the base material is preferably 10 N / cm or more, more preferably 15 N / cm or more. The peel strength is preferably 100 N / cm or less. By using this dispersion, such a laminate can be easily formed without impairing the physical properties of the F polymer in the F layer.
The porosity of the F layer is preferably 5% or less, more preferably 4% or less. The porosity is preferably 0.01% or more, more preferably 0.1% or more.
For the void ratio, the void portion of the F layer is determined by image processing from the SEM photograph of the cross section of the molded product observed using a scanning electron microscope (SEM), and the area occupied by the void portion is the area occupied by the F layer. It is the ratio (%) divided by the area. The area occupied by the void portion is obtained by approximating the void portion to a circle.

Examples of the base material include metal substrates such as metal foils such as copper, nickel, aluminum, titanium, and alloys thereof, polyimides, polyarylates, polysulfones, polyallylsulfones, polyamides, polyetheramides, polyphenylene sulfides, and polyallyl ether ketones. Examples thereof include a resin film of a film such as polyamideimide, a liquid crystal polyester, and a liquid crystal polyester amide, and a prepreg which is a precursor of a fiber-reinforced resin substrate.
Examples of the shape of the base material include a flat shape, a curved surface shape, and an uneven shape, and further, any of a foil shape, a plate shape, a film shape, and a fibrous shape may be used.
The ten-point average roughness of the surface of the base material is preferably less than 0.1 μm, more preferably 0.05 μm or less. The ten-point average roughness is preferably 0.001 μm or more. Even with such a non-roughened base material, a laminated body having excellent peel strength can be obtained from the present dispersion, and a printed circuit board or the like having excellent transmission characteristics can be formed from the laminated body. The ten-point average roughness of the surface of the base material is a value specified in Annex JA of JIS B 0601: 2013.
The thickness of the base material is preferably 2 to 100 μm. When the base material is a metal foil, the thickness of the base material is preferably 1 to 35 μm. Further, the base material may be a metal foil with a carrier, which is an ultrathin copper foil having a thickness of 2 to 5 μm laminated on the carrier copper foil via a release layer.

Preferable embodiments of the laminate include a metal-clad laminate having a metal foil and an F layer formed on at least one surface thereof, and a multilayer film having a resin film and an F layer formed on at least one surface thereof. Can be mentioned.
The metal foil in the metal-clad laminate is preferably a copper foil. Such a metal-clad laminate is particularly useful as a printed circuit board material.
The resin film in the multilayer film is preferably a polyimide film. Such a multilayer film is useful as an electric wire coating material and a printed circuit board material.
Specific examples of the polyimide film include "Kapton 50EN-S" (manufactured by Toray DuPont Co., Ltd.), "Kapton 100EN" (manufactured by Toray DuPont Co., Ltd.), "Kapton 100H" (manufactured by Toray DuPont Co., Ltd.), and " Examples include "Kapton 100KJ" (manufactured by DuPont), "Kapton 100JP" (manufactured by DuPont in the United States), and "Kapton 100LK" (manufactured by Toray DuPont Co., Ltd.).
The printed circuit board includes a flexible printed circuit board and a rigid printed circuit board.

Another base material may be further laminated on the side opposite to the base material of the F layer to form a multilayer laminate. Lamination can be performed, for example, by thermocompression bonding.
The structure of such a multilayer laminate includes a base material / F layer / another base material / F layer / base material, a metal substrate layer / another base material layer / F layer / another base material layer / metal substrate layer, and the like. Can be mentioned. Each layer may further contain a glass cloth or filler.
Such laminates are useful as antenna parts, printed substrates, aircraft parts, automobile parts, sports equipment, food industry supplies, paints, cosmetics, etc. Specifically, wire coating materials such as aircraft electric wires, electricity. Insulating tapes, insulating tapes for oil drilling, materials for printed substrates, precision filtration membranes, ultrafiltration membranes, reverse osmosis membranes, ion exchange membranes, separation membranes such as dialysis membranes and gas separation membranes, lithium secondary batteries and fuels. Electrode binders for batteries, copy rolls, furniture, automobile dashboards, covers for home appliances, load bearings, sliding shafts, valves, bearings, gears, cams, belt conveyors, sliding members such as food transport belts, shovels It is useful as a tool for shavings, cuttings, saws, boilers, hoppers, pipes, ovens, baking molds, chutes, dies, toilet bowls, and container covering materials.

When the woven fabric is impregnated with the dispersion liquid and dried by heating, an impregnated woven fabric in which the F polymer is impregnated in the woven fabric is obtained. The impregnated woven fabric can also be said to be a coated woven fabric in which the woven fabric is coated with the F layer or embedded in the F layer.
The woven fabric is preferably a glass fiber woven fabric, a carbon fiber woven fabric, an aramid fiber woven fabric or a metal fiber woven fabric, and more preferably a glass fiber woven fabric or a carbon fiber woven fabric. The woven fabric may be treated with a silane coupling agent from the viewpoint of enhancing the adhesiveness with the F layer.
The total content of the F polymer in the impregnated woven fabric is preferably 30 to 80% by mass. Examples of the method of impregnating the woven fabric with the present dispersion include a method of immersing the woven fabric in the present dispersion and a method of applying the present dispersion to the woven fabric.

When the woven fabric is dried, the F polymer may be fired. Examples of the method of firing the F polymer include a method of passing the woven fabric through a ventilation drying oven in an atmosphere of 300 to 400 ° C.
The drying of the woven fabric and the firing of the polymer may be carried out in one step. The impregnated woven fabric is excellent in characteristics such as high adhesion (adhesiveness) between the F layer and the woven fabric, high surface smoothness, and little distortion.
By thermocompression bonding the impregnated woven fabric and the metal foil, a metal-clad laminate having high peel strength and resistance to warping can be obtained, which can be suitably used as a printed circuit board material.

Further, in the production of the impregnated woven fabric, the woven fabric impregnated with the dispersion liquid is placed on the surface of the base material by sticking or the like, and is heated and dried to cause the impregnated woven fabric containing the F polymer and the woven fabric. A fabric layer may be formed to produce a laminate in which the base material and the impregnated woven fabric layer are laminated in this order.
The mode is also not particularly limited, and if a woven fabric impregnated with the present dispersion is attached to a part or all of the inner wall surface of a member such as a tank, a pipe, or a container, and the member is heated while rotating. An impregnated woven fabric layer can be formed on a part or all of the inner wall surface of the member. This manufacturing method is also useful as a lining method for the inner wall surface of members such as tanks, pipes, and containers.

As described above, this dispersion has excellent dispersion stability and can be efficiently impregnated into a porous or fibrous material. Examples of such porous or fibrous materials include materials other than the above-mentioned woven fabrics, specifically, plate-like, columnar or fibrous materials.
These materials may be pretreated with a curable resin, a silane coupling agent, or the like, or may be further filled with an inorganic filler or the like. In addition, these materials may be twisted to form threads, cables, and wires. At the time of twisting, an interposition layer made of another polymer such as polyethylene may be arranged.
An embodiment in which such a material is impregnated with the present dispersion to produce a molded product includes an embodiment in which a curable resin or a fibrous material on which the cured product is supported is impregnated with the present dispersion.

Examples of the fibrous material include high-strength and low-elongation fibers such as carbon fiber, aramid fiber, and silicon carbide fiber. As the curable resin, a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, or a polyurethane resin is preferable.
Specific examples of such an embodiment include a composite cable formed by impregnating a cable in which carbon fibers supported by a thermosetting resin are twisted with the present dispersion liquid and further heating the cable to fire an F polymer. Such a composite cable is useful as a cable for large structures, ground anchors, oil drilling, cranes, cableways, elevators, agriculture, forestry and fisheries, and slinging cables.

As described above, according to this method, the kneaded product can be obtained by kneading the liquid compound 1 with at least one other material selected from the group consisting of the powder, the inorganic filler and the different resins. By mixing the kneaded product with the liquid compound 2, a dispersion liquid having excellent dispersibility and dispersion stability can be obtained.

Although the method for producing the dispersion liquid of the present invention, the paste and the kneading powder have been described above, the present invention is not limited to the configuration of the above-described embodiment.
For example, the method for producing a dispersion liquid of the present invention may additionally have any other step in the configuration of the above embodiment, or may be replaced with any step that produces the same action.
Further, the paste and the dough of the present invention may be added with any other composition or may be replaced with any composition exhibiting the same function in the composition of the above-described embodiment.

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto.
1. 1. Preparation of each ingredient [Powder]
Powder 1: Contains 97.9 mol%, 0.1 mol%, and 2.0 mol% of TFE units, NAH units, and PPVE units in this order, and has 1000 ^{carbonyl groups per 1 × 10 6 main chain carbon atoms.} Polymer powder (D50: 2.1 μm)
Powder 2: A powder consisting of a polymer containing 98.7 mol% and 1.3 mol% of TFE units and PPVE units in this order and ^{having 40 carbonyl groups per 1 × 10 6} main chain carbon atoms (D50: 1. 8 μm)

[Inorganic filler]
Filler 1: Hollow spherical silica filler (D50: 0.7 μm, surface treated with silane coupling agent)
Filler 2: Non-hollow silica filler (D50: 0.4 μm, particle strength; 20 MPa or more)
Filler 3: Steatite Filler Filler 4: Scale-like filler made of boron nitride (D50: 14.6 μm)

[Aromatic polymer]
Varnish 1: Varnish in which thermoplastic aromatic polyimide (PI1) is dissolved in NMP [surfactant]
Surfactant 1: CH ₂ = C (CH ₃ ) C (O) OCH ₂ CH ₂ (CF ₂ ) ₆ F and CH ₂ = C (CH ₃ ) C (O) (OCH ₂ CH ₂ ) ₂₃ OH Copolymer [Liquid compound]
NMP: N-methyl-2-pyrrolidone [polyimide film]
Polyimide film 1: Aromatic polyimide film with a thickness of 50 μm (manufactured by Toray DuPont Co., Ltd., “Kapton 100LK”)

2. Production example of dispersion liquid [Example 1]
First, powder 1 and NMP were put into a pot and mixed. Further, the filler 1, the filler 2, the surfactant 1 and the varnish 1 were put into the pot and mixed to prepare a liquid composition.
Subsequently, the prepared liquid composition is put into a planetary mixer, kneaded, and powder 1 (35 parts by mass), filler 1 (14 parts by mass), filler 2 (14 parts by mass), PI1 (7 parts by mass). ), Surfactant 1 (3 parts by mass) and NMP (27 parts by mass) to obtain a paste 1. The viscosity of the paste 1 was 28,000 mPa · s.
NMP was added to the paste 1 in a plurality of times, stirred, and defoamed at 2000 rpm for 1 minute with a rotation / revolution stirrer. Further, NMP was added in a plurality of times and stirred, and 80 parts by mass of NMP as a whole was added to the paste 1 to obtain a dispersion liquid 1. The viscosity of the dispersion liquid 1 was 400 mPa · s.

[Example 2 to Example 4]
Pastes 2 to 4 were obtained in the same manner as in Paste 1, and dispersions 2 to 4 were prepared in the same manner as in dispersion 1 except that the types or amounts of powder and filler were changed.

[Example 5]
Varnish 1 and NMP were put into a pot and mixed. Further, a dry blend of powder 1, filler 1 and filler 2 was put into a pot and mixed to prepare a liquid composition.
Subsequently, the prepared liquid composition was put into a planetary mixer and kneaded. Further, the surfactant 1 is put into a planetary mixer, kneaded, and the powder 1 (35 parts by mass), the filler 1 (14 parts by mass), the filler 2 (14 parts by mass), the PI1 (7 parts by mass), and the interface. A paste 5 containing activator 1 (3 parts by mass) and NMP (27 parts by mass) was obtained. The viscosity of the paste 5 was 11000 mPa · s.
NMP was added to the paste 5 in a plurality of times and stirred, and defoamed at 2000 rpm for 1 minute with a rotation / revolution stirrer. Further, NMP was added in a plurality of times and stirred, and 80 parts by mass of NMP as a whole was added to the paste 5 to prepare a dispersion liquid to obtain a dispersion liquid 5. The viscosity of the dispersion liquid 5 was 200 mPa · s.

[Example 6]
Varnish 1 and NMP were put into a pot and mixed. Further, powder 1 was put into a pot and mixed to prepare a liquid composition.
Subsequently, the prepared liquid composition was put into a planetary mixer and kneaded to obtain a paste 6 containing powder 1 (5 parts by mass), PI1 (50 parts by mass) and NMP (45 parts by mass). The viscosity of the paste 6 was 30,000 mPa · s.
NMP was added to the paste 6 in a plurality of times and stirred, and defoamed at 2000 rpm for 1 minute with a rotation / revolution stirrer. Further, the NMP was stirred in a plurality of times, and 80 parts by mass of NMP as a whole was added to the paste 6 to prepare a dispersion liquid to obtain a dispersion liquid 6. The viscosity of the dispersion liquid 6 was 300 mPa · s.

[Example 7 (Comparative example)]
Powder 1, filler 1, filler 2, varnish 1, surfactant 1 and NMP were put into the pot, and zirconia balls were put into the pot. Then, the pot was rolled at 150 rpm for 1 hour to obtain powder 1 (35 parts by mass), filler 1 (14 parts by mass), filler 2 (14 parts by mass), PI1 (7 parts by mass), and an interface without obtaining a paste. A dispersion 7 containing activator 1 (3 parts by mass) and NMP (97 parts by mass) was obtained.

The components and viscosities of each paste are summarized in Table 1 below.

[Example 8]
Varnish 1 and NMP were put into a pot and mixed. Further, a powder mixture of powder 1 and filler 4 was put into a pot and mixed to prepare a composition. This composition is kneaded in a planetary mixer and then taken out, and the powder 1 containing powder 1 (50 parts by mass), filler 4 (40 parts by mass) and PI1 (10 parts by mass), and NMP (30 parts by mass). Got The kneaded powder 1 was lumpy and clay-like.
NMP was added to the dough 1 in a plurality of times, and the mixture was stirred while defoaming at 2000 rpm with a rotation / revolution stirrer. Further, the NMP was stirred in a plurality of times, and 80 parts by mass of NMP as a whole was added to the kneaded powder 1 to prepare a dispersion liquid, and a dispersion liquid 8 was obtained. The viscosity of the dispersion liquid 8 was 300 mPa · s.

[Example 9]
Powder 1, filler 4, varnish 1, and NMP were added to the pot and mixed to prepare a composition. This composition is kneaded in a planetary mixer and then taken out, and a kneaded powder 2 containing powder 1 (50 parts by mass), filler 4 (40 parts by mass), PI1 (10 parts by mass) and NMP (30 parts by mass). Got The kneaded powder 2 was lumpy and clay-like.
NMP was added to the dough 2 in a plurality of times, and the mixture was stirred while defoaming at 2000 rpm with a rotation / revolution stirrer. Further, the NMP was stirred in a plurality of times, and 80 parts by mass of NMP as a whole was added to the kneaded powder 2 to prepare a dispersion liquid, and a dispersion liquid 9 was obtained. The viscosity of the dispersion liquid 9 was 300 mPa · s.

[Example 10 (Comparative example)]
Powder 1 (35 parts by mass) and filler 1 (30 parts by mass) were added and stirred and mixed to obtain a powder mixture 1. The obtained powder mixture 1 and NMP (110 parts by mass) were mixed to obtain a dispersion liquid 10. In the dispersion liquid 10, it was visually observed that agglomerates were precipitated immediately after the preparation, and the dispersibility was poor.

The same as in Example 1 except that the dry blend of powder 1, filler 1 and filler 2 is charged into the planetary mixer, and the liquid composition containing the surfactant 1, varnish 1 and NMP is further charged. Even after kneading, a paste equivalent to that of Paste 1 was obtained.

3. 3. Manufacturing example of laminated body [Laminated body 1]
A wet film was formed by applying the dispersion liquid 1 after long-term storage to the surface of a long copper foil having a thickness of 18 μm using a bar coater. Next, the copper foil on which the wet film was formed was passed through a drying oven at 110 ° C. for 5 minutes and dried by heating to obtain a dry film. Then, the dry membrane was heated at 380 ° C. for 3 minutes in a nitrogen oven. As a result, a laminate 1 having a polymer layer having a thickness of 20 μm as a molded product was produced, which contained a copper foil and a melt-fired product of powder 1 and a filler 1, filler 2 and PI1 on the surface thereof.

[Laminates 2 to 9]
Laminates 2 to 9 were produced in the same manner as the laminate 1 except that the dispersion 1 was changed from the dispersion 2 to 9. In the laminated bodies 8 and 9, the thickness of the polymer layer was set to 50 μm. Since the dispersion liquid 10 had poor dispersibility, no laminate was produced from the dispersion liquid 10.

[Laminated body 10]
The dispersion liquid 1 was applied to the surface of a long copper foil having a thickness of 18 μm using a bar coater to form a wet film. Next, the copper foil on which the wet film was formed was passed through a drying oven at 110 ° C. for 5 minutes and dried by heating to obtain a dry film. Further, a dispersion liquid is applied onto the dry film using a bar coater to form a wet film, and then the dry film and the copper foil on which the wet film is formed are passed through a drying oven at 110 ° C. for 5 minutes. , It was dried by heating to obtain a two-layer dry film. Then, a polymer layer having a thickness of 50 μm was formed in the same manner as in the laminated body 1, and the laminated body 10 was manufactured.
When the cross section of the polymer layer was observed using a scanning electron microscope (SEM), the void ratio of the polymer layer of the laminate other than the laminate 7 was 5% or less, and the void ratio of the polymer layer of the laminate 7 was 5% or less. The rate was over 5%.

4. Evaluation 4-1. Evaluation of dispersion stability of dispersions After each dispersion was stored in a container at 25 ° C. for a long period of time, its dispersibility was visually confirmed, and the dispersion stability was evaluated according to the following criteria.
[Evaluation criteria]
〇: Aggregates are not visible.
Δ: Fine agglomerates are visually recognized on the side wall of the container. When lightly stirred, it was uniformly redispersed.
X: It can be visually confirmed that the agglomerates are also settled on the bottom of the container. Strong shear agitation was required for redispersion.

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

The evaluation results for the dispersion are shown in Table 2 below.

4-3. Evaluation of Linear Expansion Coefficient of Laminates For each laminate, the copper foil of the laminate was removed by etching with an aqueous ferric chloride solution to prepare a single polymer layer. A 180 mm square test piece was cut out from the prepared polymer layer, and the coefficient of linear expansion of the test piece was measured in the range of 25 ° C. or higher and 260 ° C. or lower according to the measurement method specified in JIS C 6471: 1995. Evaluated according to criteria. The laminate 7 was not evaluated because the polymer layer had a high porosity.
[Evaluation criteria]
〇: 50 ppm / ° C or less.
Δ: More than 50 ppm / ° C. and 75 ppm / ° C. or less.
X: Over 75 ppm / ° C.

4-4. Evaluation of Dielectric Dissipation Factor of Laminates For each laminate, the copper foil of the laminate is removed by etching with an aqueous ferric chloride solution to prepare a single polymer layer, which is then subjected to the SPDR (split post dielectric resonance) method. The dielectric loss tangent (measurement frequency: 10 GHz) of the polymer layer was measured and evaluated according to the following criteria. The laminate 7 was not evaluated because the polymer layer had a high porosity.
[Evaluation criteria]
〇: The dielectric loss tangent is less than 0.0010.
Δ: The dielectric loss tangent is 0.0010 or more and 0.0025 or less.
X: The dielectric loss tangent is more than 0.0025.

The evaluation results for the laminate are shown in Table 3 below.

5. Example of manufacturing a laminated film A dispersion liquid 3 prepared from a paste 3 is applied to one surface of a polyimide film 1 by a small-diameter gravure reverse method, and the NMP is passed through a ventilation drying furnace having a furnace temperature of 150 ° C. for 3 minutes. It was removed to form a dry film.
Further, the dispersion liquid 3 was similarly applied to and dried on the other surface of the polyimide film 1 to form a dry film.
Next, a polyimide film having a dry film formed on both sides was passed through a far-infrared furnace in 20 minutes to melt-fire the powder 1. The temperature of the furnace near the inlet and outlet of the far infrared path was 300 ° C, and the temperature of the furnace near the center was 340 ° C. As a result, a polymer layer having a thickness of 25 μm containing F polymer 1 and PI1 is formed on both sides of the polyimide film 1, and a laminated film 1 in which the polymer layer, the polyimide film, and the polymer layer are directly formed in this order is obtained. rice field.
When the cross section of the laminated film 1 was observed using a scanning electron microscope (SEM), the porosity of the polymer layer was 5% or less.
As a result of evaluating the linear expansion coefficient and the dielectric loss tangent of the laminated film 1 in the same manner as described above, the linear expansion coefficient was "〇" and the dielectric loss tangent was "〇".

As is clear from the above results, the dispersion liquid prepared by this method has excellent dispersibility and dispersion stability, and the cross section of the laminate obtained by applying it to the substrate is dense with no voids. there were. Therefore, the laminate using the dispersion obtained by this method was excellent in the uniformity of the component distribution and excellent in various physical properties.

Claims

A powder of a tetrafluoroethylene polymer, at least one other material selected from the group consisting of an inorganic filler and a resin different from the tetrafluoroethylene polymer, and a liquid compound are kneaded to obtain a kneaded product, and the kneaded product is obtained. A method for producing a dispersion, in which a substance and a liquid compound are mixed to obtain a dispersion.
The production method according to claim 1, wherein the solid content of the kneaded product is 40% by mass or more.
The kneaded product contains the inorganic filler, and the ratio of the powder to the inorganic filler in the kneaded product is such that the mass of the powder is 1 and the mass of the inorganic filler is 0.5 to 2. Item 2. The manufacturing method according to Item 1 or 2.
The production method according to any one of claims 1 to 3, wherein the inorganic filler is a silica filler or a boron nitride filler.
The kneaded product contains the different resin, and the ratio of the powder to the different resin in the kneaded product is 0.01 to 0.5, where the mass of the powder is 1, and the mass of the different resin is 0.01 to 0.5. The production method according to any one of claims 1 to 4.
From claim 1, the kneaded product contains the different resin, and the ratio of the powder to the different resin in the kneaded product is 1 for the mass of the powder and 2 to 1000 for the mass of the different resin. The production method according to any one of 4.
The production method according to any one of claims 1 to 6, wherein the different resin is an aromatic polymer.
The production method according to any one of claims 1 to 7, wherein the liquid compound is a low-viscosity liquid or a high-viscosity liquid.
A powder of a tetrafluoroethylene polymer, a resin different from the tetrafluoroethylene polymer, a liquid compound and a surfactant are kneaded to obtain a kneaded product, and the kneaded product and the liquid compound are mixed to obtain a dispersion liquid. Liquid manufacturing method.
A mixture containing a powder of a tetrafluoroethylene polymer and an inorganic filler and a mixture containing a resin and a liquid compound different from the tetrafluoroethylene polymer are kneaded to obtain a kneaded product, and the kneaded product and the liquid compound are mixed. A method for producing a dispersion, which comprises mixing to obtain a dispersion.
A solid content of 40 obtained by kneading a powder of a tetrafluoroethylene polymer, at least one other material selected from the group consisting of an inorganic filler and a resin different from the tetrafluoroethylene polymer, and a liquid compound. A paste having a mass% or more and a viscosity of 800 to 100,000 mPa · s.
The paste according to claim 11, wherein the paste contains the inorganic filler, and the ratio of the powder to the inorganic filler is 0.5 to 2 with the mass of the powder being 1.
11. paste.
A kneaded powder obtained by kneading a tetrafluoroethylene polymer powder, at least one other material selected from the group consisting of an inorganic filler and a resin different from the tetrafluoroethylene polymer, and a liquid compound.
The kneading powder according to claim 14, further comprising the different resins, wherein the ratio of the powder to the different resins is 0.01 to 0.5, where the mass of the powder is 1.