JP7371681B2 - Liquid composition, powder, and method for producing powder - Google Patents

Description

The present invention relates to a liquid composition, a powder, and a method for producing the powder.

A metal foil with a resin layer, which has a metal foil and an insulating resin layer, is used as a printed wiring board by forming metal conductor wiring (transmission circuit) by processing the metal foil. Printed wiring boards used for transmitting high-frequency signals are required to have excellent transmission characteristics, and an insulating resin layer with a low dielectric constant and a low dielectric loss tangent is required.
As a liquid composition for forming such an insulating resin layer, a liquid composition containing an aromatic epoxy resin and a powder of a tetrafluoroethylene polymer (see Patent Document 1) is a liquid composition containing a powder of a polyphenylene ether resin and a tetrafluoroethylene polymer. Liquid compositions containing powder (see Patent Document 2) have been proposed.
In addition, aromatic resins having an oxygen atom such as addition polymerization or polycondensation such as polyimide, polyamide, polyether, epoxy resin, polyester, and polycarbonate, and tetrafluoroethylene resin such as polytetrafluoroethylene, etc. It has excellent physical properties and is also called a super engineering plastic.
Therefore, its usage is expanding, and improvements are being made in its molecular structure (monomer structure such as monomer types and combinations, polymer structure such as stereoregularity and molecular weight distribution) and the use of its precursors. Increasingly, liquid compositions containing resins or their precursors are prepared and used as coating agents (see Patent Documents 3 to 6).

In addition, tetrafluoroethylene polymers such as polytetrafluoroethylene (PTFE), a copolymer of tetrafluoroethylene and perfluoro(alkyl vinyl ether) (PFA), and a copolymer of tetrafluoroethylene and hexafluoropropylene (FEP) can be released from molds. It has excellent physical properties such as elasticity, electrical properties, water and oil repellency, chemical resistance, weather resistance, and heat resistance, and is used in a variety of industrial applications.
It has been proposed to prepare a liquid composition by dispersing a powder of a tetrafluoroethylene polymer in a solvent and use it as a coating agent to form a film on the surface of various substrates (see Patent Documents 7 and 8). .
Patent Document 9 discloses a powder in which a polymer insoluble in a solvent is adhered to the surface of powder particles, which is prepared from a liquid composition containing a powder of a tetrafluoroethylene polymer, a predetermined solvent, and a polymer insoluble in the solvent. Proposed.

Japanese Patent Application Publication No. 2016-166347 JP2019-001965A International Publication 2018/207706 Special table 2015-519226 publication International Publication 2016/159102 Japanese Patent Application Publication No. 2008-050455 International Publication 2017/222027 International Publication 2018/016644 Japanese Patent Application Publication No. 2012-188514

The liquid composition of Patent Document 1 or 2 contains an aromatic resin known as an electrically insulating resin or its precursor, and a tetrafluoroethylene polymer with a low dielectric constant and dielectric loss tangent. The present inventors have found that while it is expected to improve the electrical properties of prepregs, metal plates with resin layers, printed wiring boards, etc., there are the following problems.
That is, when the content of the aromatic resin among the components of the liquid composition is increased, the liquid composition increases in viscosity and becomes difficult to handle, and the physical properties of the resulting molded article tend to deteriorate. Therefore, it is not possible to efficiently produce a prepreg in which a fiber base material is impregnated with a resin component at a high concentration. Furthermore, the component homogeneity is high, making it impossible to efficiently form a thick insulating resin layer.

The present inventors have also found that such liquid compositions have the following problems.
Aromatic resins or their precursors often contain oxygen atoms such as ester bonds, ether bonds, and imide bonds as bonds in the main skeleton of the resin. If the oxygen atom content and aromatic ring content of the resin material are increased in order to highly express these resin physical properties, the flame retardance of the obtained liquid composition and its molded product will decrease. . In order to solve this problem, even if a known flame retardant is added to a liquid composition, it will not be homogeneously dispersed, the flame retardance will not improve, and the original physical properties of the liquid composition or molded article will likely be impaired.
Tetrafluoroethylene resin has low surface tension and low compatibility with other materials, so molded products formed from its liquid composition also have problems with poor surface smoothness, processability, and adhesion. .
Furthermore, when preparing such a liquid composition by directly adding powder of a tetrafluoroethylene polymer to an aromatic resin varnish (liquid composition), the liquid composition tends to thicken and deteriorate in quality. The present inventors are also aware of this problem. Furthermore, the present inventors have also found that the physical properties (processability, flame retardance, electrical properties, etc.) of a molded article formed from the liquid composition in this case are difficult to sufficiently improve.
In addition, in the powder of Patent Document 9, when the tetrafluoroethylene polymer is a non-fibrillar heat-melting polymer (PFA, FEP, etc.), it is difficult for polymers insoluble in the liquid medium to adhere to the powder particle surface. The effect is still not sufficient (see paragraph number 0104 of the same document).

An object of the present invention is to provide a liquid composition that contains a well-dispersed tetrafluoroethylene polymer powder and a highly concentrated aromatic resin and has a viscosity that is easy to handle.
The present invention is directed to a predetermined fluoropolymer that can suppress deterioration such as thickening and form a highly homogeneous liquid composition even when added to a liquid composition containing a tetrafluoroethylene resin or an aromatic resin. The purpose is to provide powder.
The present invention also aims to provide a method for producing such a powder.

The present invention has the following aspects.
[1] A liquid composition containing a powder of a heat-melting tetrafluoroethylene polymer, an aromatic resin, and a liquid medium, the content of the aromatic resin being 10% by mass or more, A liquid composition, wherein the ratio of the content ratio of the tetrafluoroethylene polymer to the content ratio is 1.2 or less, and the viscosity at 25°C is 10000 mPa·s or less.
[2] The liquid composition according to [1], wherein the ratio of the content of the tetrafluoroethylene polymer to the content of the aromatic resin is 0.1 to 0.5.
[3] The aromatic resin is an aromatic polyimide resin, an aromatic polycarbonate resin, an aromatic polyamide resin, an aromatic polyester resin, an aromatic polyether sulfone resin, an aromatic maleimide resin, a polyphenylene ether resin, a polyphenylene sulfide resin, and an aromatic resin. The liquid composition according to [1] or [2], which is an aromatic resin selected from the group consisting of epoxy resins or a precursor thereof.
[4] The liquid composition according to any one of [1] to [3], wherein the liquid composition has a viscosity of 100 to 5000 mPa·s at 25°C.

[5] The liquid composition according to any one of [1] to [4], wherein the tetrafluoroethylene polymer powder is the following powder (1), the following powder (2), or the following powder (3).
Powder (1): A powder of a heat-melting tetrafluoroethylene-based polymer consisting of units based on tetrafluoroethylene and units based on perfluoro(alkyl vinyl ether), whose volume-based cumulative 50% diameter is 10 to 60 μm. powder.
Powder (2): Hot-melting tetrafluorocarbon containing 90 to 99 mol% of units based on tetrafluoroethylene, 1 to 3 mol% of units based on perfluoro(alkyl vinyl ether), and units based on a monomer having an oxygen-containing polar group. An ethylene polymer powder having a volume-based cumulative 100% diameter of 8 μm or less.
Powder (3): A powder containing a heat-melting tetrafluoroethylene polymer and a surface treatment agent, the powder having a volume-based cumulative 50% diameter of less than 25 μm.
[6] The powder (1) is a powder of a heat-melting tetrafluoroethylene polymer containing 92 to 98 mol% of units based on tetrafluoroethylene and 2 to 8 mol% of units based on perfluoro(alkyl vinyl ether). The liquid composition according to [5], which is a powder having a volume-based cumulative 50% diameter of 10 to 60 μm.
[7] The liquid composition according to [5] or [6], wherein the volume-based cumulative 50% diameter of the powder (1) is 16 to 40 μm.
[8] The powder (1) includes a first powder having a volume-based cumulative 50% diameter of 8 μm or less and a second powder having a volume-based cumulative 50% diameter of 16 to 40 μm, and The liquid composition according to any one of [5] to [7], wherein the first powder has a content ratio of 0.5 or less.
[9] The liquid composition according to [5], wherein the powder (3) is a powder in which the mass ratio of the surface treatment agent to the heat-melting tetrafluoroethylene polymer is more than 0.01 and not more than 0.25. .

[10] The liquid composition according to any one of [1] to [9] above is impregnated into a fiber base material, and the prepreg containing the dried product of the liquid composition and the fiber base material is further dried. Production method.
[11] Applying the liquid composition according to any one of [1] to [9] above to the surface of a metal plate and heating it to form a resin layer containing a dried product of the liquid composition, A method for manufacturing a resin layer-coated metal plate, which obtains a resin-layer-coated metal plate having a metal plate and the resin layer.

[12] The following powder (1), the following powder added to a liquid composition containing at least one resin material selected from the group consisting of a non-melting tetrafluoroethylene polymer and an aromatic resin and a liquid medium. A powder consisting of (2) or the following powder (3).
Powder (1): A powder of a heat-melting tetrafluoroethylene-based polymer consisting of units based on tetrafluoroethylene and units based on perfluoro(alkyl vinyl ether), whose volume-based cumulative 50% diameter is 10 to 60 μm. powder.
Powder (2): Hot-melting tetrafluorocarbon containing 90 to 99 mol% of units based on tetrafluoroethylene, 1 to 3 mol% of units based on perfluoro(alkyl vinyl ether), and units based on a monomer having an oxygen-containing polar group. An ethylene polymer powder having a volume-based cumulative 100% diameter of 8 μm or less.
Powder (3): A powder containing a heat-melting tetrafluoroethylene polymer and a surface treatment agent, the powder having a volume-based cumulative 50% diameter of less than 25 μm.
[13] The powder according to [12], wherein the surface treatment agent is a surfactant or a silane coupling agent.

[14] A powder dispersion containing a raw material powder of the heat-melting tetrafluoroethylene polymer, a surface treatment agent, and a liquid medium is concentrated, and the liquid medium is further separated. A method for producing a powder containing a surface treating agent, wherein the mass ratio of the surface treating agent to the heat-melting tetrafluoroethylene polymer contained in the produced powder is more than 0.01 and not more than 0.25. How to make powder.
[15] The manufacturing method according to [14], wherein the volume-based cumulative 50% diameter of the powder is less than 25 μm.

The liquid composition of the present invention contains a well-dispersed heat-melting tetrafluoroethylene polymer powder and a high concentration of aromatic resin, and has excellent handleability. By using the liquid composition of the present invention, it is possible to easily produce a prepreg in which a fiber base material is impregnated with a resin component at a high concentration and a base material having an insulating resin of any thickness. These prepregs and base materials have excellent electrical properties because the heat-melting tetrafluoroethylene polymer has high homogeneity.
Further, according to the present invention, excellent dispersibility can be achieved in a liquid composition containing a liquid medium and at least one resin material selected from the group consisting of a non-melting tetrafluoroethylene polymer and an aromatic resin. It is possible to provide an additive containing a powder of a heat-melting tetrafluoroethylene polymer, which can improve the physical properties (surface smoothness, flame retardance, processability, etc.) of a molded article formed therefrom.
Furthermore, according to the powder manufacturing method of the present invention, a powder containing a heat-melting tetrafluoroethylene polymer can be obtained.

The following terms have the following meanings:
The "viscosity of the liquid composition" is the viscosity of the liquid composition measured using a B-type viscometer at 25° C. and at a rotation speed of 30 rpm. The measurement is repeated three times, and the average value of the three measurements is taken.
The "thixotropic ratio of a liquid composition" is a value calculated by dividing the viscosity η ₁ measured at 25°C and a rotation speed of 30 rpm by the viscosity η ₂ measured at a rotation speed of 60 rpm ( η ₁ /η ₂ ).
"Thermofusible polymer" means a polymer that exhibits melt flowability, and has a melt flow rate of 0.1 to 1000 g/10 min under a load of 49 N at a temperature 20°C or more higher than the melting temperature of the polymer. It means a polymer that exists at a temperature of . In addition, "melt flow rate" means the melt mass flow rate (MFR) of a polymer as defined in JIS K 7210:1999 (ISO 1133:1997).
The "melting temperature (melting point) of a polymer" is the temperature corresponding to the maximum value of the melting peak of a polymer measured by differential scanning calorimetry (DSC).
"Polymer melt viscosity" is determined in accordance with ASTM D 1238, using a flow tester and a 2Φ-8L die, a polymer sample (2 g) that has been heated in advance at the measurement temperature for 5 minutes is subjected to a load of 0.7 MPa. This is the value measured by holding the device at the measurement temperature.
"Storage modulus of polymer" is a value measured based on ISO 6721-4:1994 (JIS K7244-4:1999).

"Ten-point average roughness (Rzjis) of a substrate or metal plate" is a value specified in Annex JA of JIS B 0601:2013.
The "volume-based cumulative 50% diameter (D50) of the powder" is determined by dispersing the powder in water and using a laser diffraction/scattering type particle size distribution measuring device (manufactured by Horiba, Ltd., LA-920 measuring instrument) to determine the particle size of the powder. The distribution is measured, a cumulative curve is determined with the total volume of the powder particle population as 100%, and the particle size is the point on the cumulative curve where the cumulative volume is 50%.
"Powder's volume-based cumulative 90% diameter (D90)" is the particle diameter at the point where the cumulative volume is 90% on the cumulative curve obtained in the same manner.
"Volume-based cumulative 100% diameter of powder (D100)" is the particle size at the point where the cumulative volume becomes 100% on the cumulative curve obtained in the same manner.
A "unit" in a polymer may be an atomic group formed directly from one monomer molecule through a polymerization reaction, or a polymer obtained through a polymerization reaction may be treated in a predetermined manner to partially convert its structure. It may be the above-mentioned atomic group. A unit based on monomer A contained in a polymer is also simply referred to as "unit A."
"(Meth)acrylate" is a general term for acrylate and methacrylate.

The liquid composition of the present invention (hereinafter also referred to as "liquid composition (1)") is a powder of a heat-melting tetrafluoroethylene polymer (hereinafter also referred to as "F polymer") (hereinafter referred to as "F powder"). ), an aromatic resin, and a liquid medium, and has a viscosity of 10,000 mPa·s or less at 25°C. Liquid composition (1) is a powder dispersion in which F powder is dispersed in a liquid composition.
In the liquid composition (1), the aromatic resin content is 10% by mass or more, and the ratio (mass ratio) of the F polymer content to the aromatic resin content is 1.2 or less.

In the liquid composition (1), even though the aromatic resin content is high, the F powder is in a good dispersion state, the viscosity is converged within a predetermined range, and the handling property (coating property, impregnation property, etc.) is improved. Excellent.
This is considered to be because the ratio is within a predetermined range and the aromatic resin contained in a high concentration promotes dispersion of the F powder both as a solute and as a solvent. As a result, the dispersion rate of the F powder in the liquid composition (1) becomes higher than the sedimentation rate, and it is thought that the physical properties of the liquid composition (1) are less likely to be impaired. Therefore, when liquid composition (1) is used, molded products (prepreg, metal plate with resin layer, printed wiring board, etc.) with excellent electrical properties can be formed even if the content of F polymer is relatively low. it is conceivable that.

The content rate of the aromatic resin in the liquid composition (1) is 10% by mass or more, preferably 20% by mass or more, and more preferably 40% by mass or more. The upper limit thereof is preferably 80% by mass.
The ratio of the F polymer content to the aromatic resin content in the liquid composition (1) is 1.2 or less, preferably less than 1, more preferably 0.1 to 0.5, and 0.1 to 0.4 is particularly preferred. As described above, even if the content of the F polymer is relatively low, the liquid composition (1) can impart the physical properties of the F polymer, such as electrical properties, to the molded article.
The viscosity of the liquid composition (1) is 10,000 mPa·s or less, preferably 100 to 5,000 mPa·s, more preferably 500 to 4,000 mPa·s.

The F polymer in the liquid composition (1) is a heat-melting polymer having units based on tetrafluoroethylene (hereinafter also referred to as "TFE"). The F polymer may be a copolymer of TFE and a comonomer copolymerizable with TFE, or may be a polymer that can be substantially a homopolymer of TFE as long as it is heat-meltable. The F polymer preferably has 90 to 100 mol% of TFE units based on all units constituting the polymer. The fluorine content of the F polymer is preferably 70 to 76% by mass, more preferably 72 to 76% by mass.
Examples of the F polymer include thermofusible polytetrafluoroethylene, a copolymer of TFE and ethylene (ETFE), a copolymer of TFE and propylene, and a copolymer of TFE and perfluoro(alkyl vinyl ether) (hereinafter also referred to as "PAVE"). copolymer (PFA), copolymer (FEP) of TFE and hexafluoropropylene (hereinafter also referred to as "HFP"), copolymer of TFE and fluoroalkyl ethylene (hereinafter also referred to as "FAE"), copolymer of TFE and chloropropylene (hereinafter also referred to as "FAE"), Mention may be made of copolymers with fluoroethylene. Note that the copolymer may further have units based on other comonomers.

The F polymer is a heat-melting polymer, and preferably has a melting temperature of 260 to 320°C. The F polymer has excellent resistance to physical stress such as shear force and excellent processability, and is unlikely to change in quality during the preparation or use of the liquid composition (1). As a result, dispersibility, homogeneity, etc. are more likely to be excellent.
The storage modulus of the F polymer at 200 to 260°C is preferably 0.1 to 5.0 MPa, more preferably 0.5 to 3.0 MPa. In this case, warping of the laminate formed from the liquid composition (1) can be easily suppressed. For example, when manufacturing a printed wiring board from a resin-layered metal plate having a resin layer formed from the liquid composition (1), peeling due to warpage of the resin layer in a solder reflow process is likely to be suppressed.
The melt viscosity of the F polymer is preferably 1×10 ² to 1×10 ⁶ Pa·s at 380°C, more preferably 1×10 ² to 1×10 ⁶ Pa·s at 300°C. In this case, the F powder tends to pack tightly and form a highly smooth resin layer. Further, such a resin layer serves as a heat insulating layer in the solder reflow process, and can more easily reduce damage (peeling, blistering, etc.) to other layers.

Suitable specific examples of F polymers include low molecular weight PTFE, modified PTFE, FEP, and PFA. Note that low molecular weight PTFE and modified PTFE also include copolymers of TFE and trace amounts of comonomers (HFP, PAVE, FAE, etc.).
The F polymer preferably has a TFE unit and a functional group. As the functional group, a carbonyl group-containing group, a hydroxy group, an epoxy group, an amide group, an amino group, and an isocyanate group are preferable. Also preferred are oxygen-containing polar groups described below. The functional group may be contained in a unit in the F polymer or may be contained in a terminal group of the main chain of the polymer. Examples of the latter polymer include polymers having functional groups as terminal groups derived from polymerization initiators, chain transfer agents, and the like. Also included is an F polymer having a functional group, which is obtained by subjecting the F polymer to plasma treatment or ionizing radiation treatment.

The F polymer having a functional group is preferably an F polymer having a TFE unit and a unit having a functional group from the viewpoint of dispersibility of the F powder in the liquid composition (1) and interaction with the aromatic resin. As the unit having a functional group, a unit based on a monomer having a functional group is preferable, and a unit based on a monomer having a carbonyl group-containing group, a hydroxy group, an epoxy group, an amide group, an amino group, or an isocyanate group is more preferable.
As the monomer having a carbonyl group-containing group, a cyclic monomer having an acid anhydride residue, a monomer having a carboxy group, a vinyl ester, and a (meth)acrylate are preferable, and a cyclic monomer having an acid anhydride residue is more preferable. Examples of the cyclic monomer having an acid anhydride residue include itaconic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride (also known as hymic anhydride, hereinafter also referred to as "NAH"), and anhydride. Maleic acid is particularly preferred.

Preferred specific examples of F polymers having functional groups include TFE units, HFP units, PAVE units, or FAE units, and units based on monomers having functional groups (hereinafter also referred to as "functional units"). F polymer is mentioned.
As PAVE, CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ , CF ₂ =CFOCF ₂ CF ₂ CF ₃ (hereinafter also referred to as "PPVE"), CF ₂ =CFOCF ₂ CF ₂ CF ₂ CF ₃ , _CF2 =CFO( _CF2 ) _8F is mentioned.
As FAE, _CH2 =CH( _CF2 ) _2F , _CH2 =CH( _CF2 ) _3F , _CH2 =CH( _CF2 ) _4F , _CH2 =CF( _CF2 ) _3H , _CH2 =CF( _CF2 ) _4H is mentioned.
Such F polymer contains 90 to 99 mol% of TFE units, 0.5 to 9.97 mol% of HFP units, PAVE units, or FAE units, and 0.01 to 0.01 to 9.9 mol% of functional units, based on the total units constituting the polymer. It is preferable to have 3 mol % of each. Specific examples of such F polymers include the polymers described in International Publication No. 2018/16644.

Although the F powder in the liquid composition (1) may contain components other than the F polymer (such as an aromatic resin), it is preferable that the F powder is the main component. The content of the F polymer in the F powder is preferably 80% by mass or more, and more preferably 100% by mass. Further, the surface of the F powder may be coated with silica.
The D50 of F powder is preferably 10 to 60 μm, more preferably 12 to 50 μm, and particularly preferably 16 to 40 μm. In this range, the F powder is less likely to settle and is more easily dispersed without impairing the state (viscosity, etc.) of the liquid composition (1).

A preferred embodiment of the F powder includes a blended powder containing a first powder with a D50 of 8 μm or less and a second powder with a D50 of 16 to 50 μm.
The D50 of the first powder is preferably 0.1 μm or more. In this case, the ratio (mass ratio) of the content of the first powder to the content of the second powder in the F powder is preferably 0.5 or less, more preferably 0.2 or less. The ratio is preferably 0.01 or more. When the first and second powders are included in such a mass ratio, these powders are highly packed, and it is easy to form a resin layer with high smoothness and few voids.
Note that even if the F powder is composed of multiple types of powders with different D50s, it is sufficient that the D50 of the F powder as a whole is 10 to 60 μm.

Further, the F powder is preferably the following powder (1), the following powder (2), or the following powder (3).
Powder (1): A powder of F polymer consisting of TFE units and PAVE units, the powder having a D50 of 10 to 60 μm.
Powder (2): Powder of F polymer containing 90 to 99 mol% of TFE units, 1 to 3 mol% of PAVE units, and units based on monomers having oxygen-containing polar groups, whose D100 is 8 μm or less. ,powder.
Powder (3): A powder containing an F polymer and a surface treatment agent, the powder having a D50 of less than 25 μm.
Details of the above powders (1) to (3) will be described later.

The aromatic resin in the liquid composition (1) is a resin different from the F polymer. The aromatic resin in the present invention also means a precursor of an aromatic resin that becomes an aromatic resin by heating, etc., and also includes an aromatic resin or its precursor, and aromatic resin molecules such as a crosslinking agent and a curing agent. It also means a combination with components forming a skeleton. Examples of the aromatic resin precursor include monomers that form the aromatic resin, and partial reactants (also referred to as prepolymers, half-reactants, and semi-cured products) of the monomers.
The aromatic resin may be liquid or solid. The aromatic resin may be a non-curing resin or a curable resin. Examples of non-curable resins include thermofusible resins and cured thermosetting resins.

The aromatic resin is selected from the group consisting of aromatic polyimide resin, aromatic polycarbonate resin, aromatic polyamide resin, aromatic polyester resin, aromatic polyether sulfone resin, polyphenylene ether resin, polyphenylene sulfide resin, and aromatic epoxy resin. The aromatic resins and their precursors are preferred.
In addition, aromatic resins are further chemically modified with reactive groups (vinyl groups, (meth)acryloyloxy groups, hydroxy groups, amino groups, epoxy groups, etc.) and halogen atoms (bromine atoms, fluorine atoms, etc.). Good too.
Suitable specific examples of aromatic resins include aromatic epoxy resins, aromatic polyimide resins, polyamic acids that are precursors of aromatic polyimide resins, aromatic polyester resins, polyphenylene ether resins, and precursors thereof. . In this case, the F polymer also functions as a flame retardant, and the flame retardance of the molded article formed from the liquid composition of the present invention is more likely to be improved.

Aromatic epoxy resins include various types such as naphthalene type, cresol novolac type, bisphenol A type, bisphenol F type, bisphenol S type, cresol novolac type, phenol novolac type, alkylphenol novolak type, biphenol type, and trishydroxyphenylmethane type. Examples include epoxy resins.
Also included are epoxides of condensates of phenol and aromatic aldehydes having a phenolic hydroxyl group, diglycidyl ethers of bisphenol, diglycidyl ethers of naphthalene diol, and glycidyl ethers of phenol.

Examples of the aromatic tetracarboxylic dianhydride that forms the aromatic polyimide resin or its precursor (polyamic acid) include pyromellitic dianhydride and 3,3'4,4'-biphenyltetracarboxylic dianhydride. , 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetra Carboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis( 2,3-dicarboxyphenyl)propane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride , bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 3,4, 9,10-perylenetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 3,3',4 , 4'-benzophenone tetracarboxylic dianhydride, 2,3,2',3'-benzophenone tetracarboxylic dianhydride, 2,3,3',4'-benzophenone tetracarboxylic dianhydride, 1, 2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,4,5-naphthalenetetracarboxylic dianhydride, 1,4, 5,8-naphthalenetetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8 -Tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride, bis(3,4-dicarboxyphenyl)methylphenylsilane dianhydride, bis(3,4-dicarboxyphenyl)diphenylsilane dianhydride , 1,4-bis(3,4-dicarboxyphenyldimethylsilyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldicyclohexane dianhydride Anhydride, p-phenylenebis(trimellitic acid monoester acid anhydride), 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 2,2-bis[4-(3, 4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 4,4-bis(3,4-dicarboxyphenoxy)phenyl] carboxyphenoxy) diphenyl sulfide dianhydride.

In addition, aromatic diamines forming the aromatic polyimide resin or its precursor (polyamic acid) include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenyl ether, 4,4' -diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenyldifluoromethane, 4,4' - Diaminodiphenyl difluoromethane, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfide, 3,4'-diaminodiphenylsulfide , 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 4,4'-diaminodiphenyl ketone, 2,2-bis(3-aminophenyl)propane, 2,2-(3,4'-diaminodiphenyl)propane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-(3, 4'-diaminodiphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene , 3,3'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 3,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 4,4'-[1 , 4-phenylenebis(1-methylethylidene)]bisaniline, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, bis[4-(3-aminophenoxy) phenyl] sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, 1,3- Examples include bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, and 1,5-bis(4-aminophenoxy)heptane.

Examples of the aromatic polyester resin include solvent-soluble liquid crystal aromatic polyesters. Examples of such aromatic polyesters include the polymers described in paragraphs [0019] to [0042] of JP-A-2010-031256, and more specifically, 2-hydroxy-6-naphthoic acid, isophthalic acid, and Examples include a reaction product of diphenyl ether-4,4'-dicarboxylic acid, 4-hydroxyacetonilide, and acetic anhydride.
Examples of the polyphenylene ether resin or its precursor include 2,6-dimethylphenol, polyphenol derivatives, and reactants of both.

Although the liquid composition (1) contains the F polymer which has poor interaction with other substances, the powder (F powder) is well dispersed without deterioration such as thickening. According to the present invention, it is also possible to provide a liquid composition containing a high concentration of aromatic resin in which F powder is dispersed and which is substantially free of components that promote dispersion of F powder. Examples of the components include fluorosurfactants, silicone surfactants, and hydrocarbon surfactants.
In other words, the liquid composition (1) does not contain any fluorine-containing compound other than the above-mentioned components, especially the F-polymer, or, if it contains the above-mentioned fluorine-containing compound, the content of the fluorine-containing compound relative to the content ratio of the F-polymer. It is preferable that the proportion ratio (mass ratio) is 0.05 or less. The ratio is more preferably 0.01 or less. Such a liquid composition (1) is easier to manufacture and adjust its physical properties.
Note that aromatic resins having fluorine atoms are not included in the above-mentioned fluorine-containing compounds.

Liquid composition (1) contains a liquid medium. The content of the liquid medium in the liquid composition (1) is preferably 40% by mass or less, more preferably 5 to 30% by mass.
In the liquid composition (1), since the content ratio of the aromatic resin and the ratio of the content ratio of the F polymer to the aromatic resin are within a predetermined range, even if it contains a liquid medium, the deterioration of the F polymer due to the liquid medium is suppressed and increases. Not easily sticky. Furthermore, since it contains aromatic resin at a high concentration, F powder is difficult to settle even if it contains a liquid medium, and has excellent dispersion stability.
The liquid medium is a compound that is liquid at 25°C, and is appropriately selected depending on the type of aromatic resin. The liquid medium is preferably a compound that has a lower boiling point than other components contained in the liquid composition (1) and can be removed by volatilization. Two or more liquid media may be used in combination.

Specific examples of liquid media include water, alcohol (ethanol, 2-propanol, 1-butanol, etc.), nitrogen-containing compounds (N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, etc.) ), sulfur-containing compounds (dimethyl sulfoxide, etc.), ethers (dibutyl ether, dioxane, etc.), esters (ethyl lactate, butyl acetate, γ-butyrolactone, etc.), ketones (acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, 2-heptanone) , cycloheptanone, cyclohexanone, etc.), hydrocarbon compounds (hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, toluene, xylene), glycol ethers (ethylene glycol monoisopropyl ether, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.).

The liquid composition (1) preferably contains an inorganic filler from the viewpoint of further suppressing warping of the formed molded product. Examples of inorganic fillers include silica, alumina, and boehmite. Spherical silica is preferred from the viewpoint of not only suppressing warpage but also improving workability. When containing an inorganic filler, the content of the inorganic filler in the liquid composition (1) is preferably 25% by mass or less.
The liquid composition (1) may further contain agents other than the above-mentioned components. Such agents include thixotropic agents, antifoaming agents, silane coupling agents, dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, colorants, and conductive agents. agent, mold release agent, surface treatment agent, viscosity modifier, and flame retardant.

Liquid composition (1) is prepared by combining F powder and aromatic resin as necessary under conditions such that the content ratio of aromatic resin is 10% by mass or more and the ratio of the content ratio of F polymer to it is 1.2 or less. It can be manufactured by mixing other components as required, and is preferably manufactured by adding F powder to a liquid raw material composition containing an aromatic resin. As described above, since the F powder has high dispersibility in aromatic resins, a liquid composition with a high aromatic resin content can be easily produced.

The liquid composition (1) contains F powder that is well dispersed and aromatic resin at a high concentration, and has excellent handling properties.
If a fiber base material is impregnated with the liquid composition (1) and further dried, a prepreg containing a dried product of the liquid composition (1) and the fiber base material is obtained. The dried material is a solid material formed from the liquid composition (1). For example, when the liquid composition (1) is curable, it is a cured material formed from the liquid composition (1). When 1) contains a liquid medium, it is a solidified product formed by removing the liquid medium from it. Note that these cured products also include semi-cured products.
The prepreg is a prepreg containing a dried product of the liquid composition (1) and a fiber base material, and can also be said to be a prepreg having an F polymer and an aromatic resin as a matrix resin, and the F polymer has high homogeneity. It is a prepreg that is impregnated with aromatic resin at a high concentration.

The fiber base materials include a reinforcing fiber bundle made of a plurality of reinforcing fibers, a cloth woven with the reinforcing fiber bundles, a unidirectional reinforcing fiber bundle in which a plurality of reinforcing fibers are aligned in one direction, and the unidirectional reinforcing fibers. Examples include a unidirectional cloth made up of bundles, a fiber bundle made by combining these, and a fiber bundle made by stacking a plurality of reinforcing fiber bundles.
As the reinforcing fibers, continuous long fibers having a length of 10 mm or more are preferable. The reinforcing fibers do not need to be continuous over the entire length in the length direction or the entire width in the width direction of the reinforcing fiber sheet, and may be separated in the middle.
Examples of reinforcing fibers include inorganic fibers, metal fibers, and organic fibers.

Examples of inorganic fibers include carbon fibers, graphite fibers, glass fibers, silicon carbide fibers, silicon nitride fibers, alumina fibers, silicon carbide fibers, and boron fibers.
Examples of metal fibers include aluminum fibers, brass fibers, and stainless steel fibers.
Examples of organic fibers include aromatic polyamide fibers, polyaramid fibers, polyparaphenylenebenzoxazole (PBO) fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers, and polyethylene fibers.
As reinforcing fibers used in prepregs for printed circuit boards, glass fibers are preferred, and opened glass cloth is more preferred.
The reinforcing fibers may be surface-treated. Two or more types of reinforcing fibers may be used in combination.

When a fiber base material is impregnated with the liquid composition (1) and further dried, the impregnated material may be heated. Regarding the heating conditions, if the liquid composition (1) is curable, heating may be performed at a temperature higher than the curing temperature, and if the liquid composition (1) contains a liquid medium, heating may be performed at a temperature higher than the boiling point of the liquid medium. Just heat it.
Drying may be performed in one stage at a constant temperature, or may be performed in two or more stages at different temperatures. Examples of the drying method include a method using an oven, a method using a ventilation drying oven, and a method of irradiating with heat rays such as infrared rays. Drying may be carried out either under normal pressure or under reduced pressure. The drying atmosphere may be any of an oxidizing gas atmosphere (oxygen gas, etc.), a reducing gas atmosphere (hydrogen gas, etc.), or an inert gas atmosphere (helium gas, neon gas, argon gas, nitrogen gas, etc.). .

According to the present invention, a metal plate with a resin layer has a metal plate and a resin layer in this order, and the resin layer contains a dried liquid composition (1) (hereinafter also referred to as a metal plate with a resin layer (1)). ) can be provided. At this time, the above-mentioned prepreg can also be used as the dried material.
The metal plate with a resin layer (1) contains an electrically insulating aromatic resin and an F polymer with a low dielectric constant and a low dielectric loss tangent, and the F polymer has high homogeneity, excellent electrical properties, and is resistant to warping.
Specifically, the dielectric constant (20 GHz) of the metal plate with resin layer (1) is preferably 3.6 or less, more preferably 3.2 or less. Further, the dielectric loss tangent (20 GHz) is preferably 0.009 or less, more preferably 0.003 or less.
Further, the linear expansion coefficient of the resin layer-coated metal plate (1) is preferably -10 to +10 ppm/°C.

Examples of the material of the metal plate include copper, copper alloy, stainless steel, nickel, nickel alloy (including 42 alloy), aluminum, aluminum alloy, titanium, titanium alloy, and the like.
The thickness of the metal plate is preferably 1 to 30 μm.
Examples of the metal plate include copper foils such as rolled copper foil and electrolytic copper foil. The surface of the metal plate may be provided with a rust-preventing layer (such as an oxide film such as chromate), a heat-resistant layer, a roughening treatment layer, and a silane coupling agent treatment layer.
The ten-point average roughness of the surface of the metal plate is preferably 0.2 to 2.5 μm. In this case, the adhesiveness between the metal plate and the resin layer tends to be good.
The metal plate with resin layer (1) may include a metal plate in contact with at least one surface of the resin layer. The layer structure includes metal plate/resin layer, metal plate/resin layer/metal plate, resin layer/metal plate/resin layer, metal plate/resin layer/other substrate/resin layer/metal plate.
Note that "metal plate/resin layer" indicates that a metal plate and a resin layer are laminated in this order, and the same applies to other layer configurations.

The metal plate with a resin layer (1) is produced by layering the liquid composition (1) or a dried product of the liquid composition (1) (such as the prepreg described above) on the surface of the metal plate and then heating it. preferable.
Regarding the heating conditions, when using the prepreg described above, it is preferable to heat at 160 to 220°C. Moreover, it is preferable to employ a hot press method for heating at this time. That is, it is preferable to stack the prepreg described above on the surface of a metal plate and bond it under thermocompression at a pressure of 0.2 to 10 MPa.
The hot pressing is preferably carried out in a vacuum atmosphere of 20 kPa or less from the viewpoint of suppressing air bubbles and deterioration due to oxidation.

In the resin layer-coated metal plate (1), the surface of the resin layer may be surface-treated in order to control the linear expansion coefficient of the resin layer or to further improve the adhesiveness of the resin layer.
Examples of the surface treatment include annealing treatment, corona discharge treatment, atmospheric pressure plasma treatment, vacuum plasma treatment, UV ozone treatment, excimer treatment, chemical etching, silane coupling treatment, and micro-roughening treatment.
In the annealing treatment, the temperature is preferably 80 to 190°C, the pressure is preferably 0.001 to 0.030 MPa, and the time is preferably 10 to 300 minutes.

The metal plate with resin layer (1) contains a high concentration of aromatic resin and homogeneous F polymer, so it has excellent physical properties such as electrical properties and chemical resistance (etching resistance), and is suitable for flexible printed wiring boards. , can be used for printed wiring boards such as rigid printed wiring boards.
For example, the metal plate (1) with a resin layer may be etched to form a metal conductor wiring (transmission circuit) in a predetermined pattern, or the metal plate (1) may be processed by electrolytic plating (semi-additive method). A printed wiring board can be manufactured from the resin layer-coated metal plate (1) by processing it into metal conductor wiring using a modified semi-additive method, etc.).
This printed wiring board has metal conductor wiring and a resin layer in this order. The resin layer is a dried product of the liquid composition (1), and its structure includes metal conductor wiring/resin layer, metal conductor wiring/resin layer/metal conductor wiring.

In manufacturing a printed wiring board, after forming the metal conductor wiring, an interlayer insulating film may be formed on the metal conductor wiring, and further metal conductor wiring may be formed on the interlayer insulating film. The interlayer insulating film may also be formed using liquid composition (1).
Further, a solder resist or a coverlay film may be laminated on the metal conductor wiring. The solder resist and coverlay film may be formed using the liquid composition (1).
A specific embodiment of the printed wiring board includes a multilayer printed wiring board in which the above-mentioned layer structure is multilayered.

A preferred embodiment of the multilayer printed wiring board is an embodiment in which the outermost layer of the multilayer printed wiring board is a resin layer containing a dried liquid composition (1), and has one or more layer configurations of metal conductor wiring/the resin layer. can be mentioned.
In the above aspect, a part of the resin layer may be replaced with an F polymer layer containing F polymer as a main component, and specifically, metal conductor wiring/the resin layer/metal conductor wiring/F polymer The layer structure may be layer/metal conductor wiring/the resin layer.
In the multilayer printed wiring board of this embodiment, the outermost layer has excellent heat resistance, and interfacial peeling between the metal conductor wiring and the resin layer is unlikely to occur even when heated during processing, for example, at 300°C during the solder reflow process. .

The powder of the present invention is a liquid composition (hereinafter also referred to as "liquid composition (p)") containing at least one resin material selected from the group consisting of a non-melting tetrafluoroethylene polymer and an aromatic resin. ) is a powder that is used by adding it to. The powder of the present invention is hereinafter also referred to as "additive (1)."
The additive (1) is the following powder (1), the following powder (2), or the following powder (3).
Powder (1): A powder of F polymer consisting of TFE units and PAVE units, whose D50 is 10 to 60 μm.
Powder (2): Powder of F polymer containing 90 to 99 mol% of TFE units, 1 to 3 mol% of PAVE units, and units based on monomers having oxygen-containing polar groups, whose D100 is 8 μm or less. ,powder.
Powder (3): A powder containing an F polymer and a surface treatment agent, the powder having a D50 of less than 25 μm.

The F polymer in powder (1) is preferably a polymer containing 92 to 98 mol% of TFE units and 2 to 8 mol% of PAVE units.
In contrast to the F polymer in powder (1), the F polymer in powder (2) is a unit based on a monomer having an oxygen-containing polar group (hereinafter also referred to as a "polar monomer") (hereinafter referred to as a "polar unit"). ).
The F polymer in powder (3) may be the same F polymer as the F polymer in powder (1) and powder (2), or may be an F polymer other than these. Examples of the F polymer in the powder (3) include the F polymer that constitutes the F powder in the liquid composition (1).

Hereinafter, the F polymer in powder (1) is "added polymer (1)", the F polymer in powder (2) is "added polymer (2)", the F polymer in powder (3) is "added polymer (3)", Also written as In addition, when each polymer is referred to collectively, it is also referred to as "added polymer", and when each powder is collectively referred to, it is also referred to as "added powder".
The ratio (mol%) of each unit in the added polymer is the ratio of each unit to the total units constituting the added polymer.

The additive (1) has excellent dispersibility in the liquid composition (p) containing a resin material, and imparts flame retardancy and processing properties to the molded product (including molded parts such as resin layers, etc.) obtained therefrom (including molded parts such as resin layers, etc.). Physical properties such as properties can be imparted. Furthermore, the original physical properties of the resulting molded product are maintained or even improved.
Although the reason for this is not necessarily clear, it is thought that the additive powder contains an additive polymer having a predetermined polymer composition and has a predetermined particle size.

That is, the powder (1) contains the additive polymer (1) containing PAVE units, and its D50 is relatively large. Further, the additive polymer (1) preferably contains 2 to 8 mol% of PAVE units. As a result, it is thought that it has high fluidity both chemically and physically. In addition, since the D50 is relatively large, the surface area per mass decreases, and the contact with the components of the liquid composition (p) decreases relatively, which alleviates the low affinity between the components and improves their dispersibility. It is also thought that it will improve. Furthermore, if each particle constituting the powder (1) is considered to be an aggregate of primary particles of the added polymer 1, it is also considered that this is due to a decrease in the bulk density of the powder (1).
Due to these synergistic effects, the powder (1) added to the liquid composition (p) has a higher dispersion rate than the sedimentation rate, and has good properties without impairing the physical properties of the liquid composition (p). It is thought that it was dispersed into As a result, the molded product formed from the liquid composition (p) to which the powder (1) has been added has the inherent properties (weather resistance, heat resistance, chemical resistance, impact resistance, electrical properties, etc.) due to the resin material. It is inferred that the high physical properties due to the added polymer were able to be exhibited while maintaining the properties (hereinafter the same applies).

On the other hand, the powder (2) contains the additive polymer (2) containing polar units and is considered to have a strong interaction with the resin material of the liquid composition (p), but its D100 is relatively small. If so, it will not contain powder with large particle size or its content will be small. Therefore, thickening of the liquid composition (p) and sedimentation of the components due to the interaction between the resin material and the powder (2) are likely to be suppressed. As a result, molded products formed from the liquid composition (p) to which powder (2) has been added can exhibit the high physical properties caused by the added polymer (2) while maintaining the original properties caused by the resin material. It is assumed that.

Furthermore, since the powder (3) contains a surface treatment agent, even if it has a small particle size with a D50 of less than 25 μm, it is highly dispersed in the liquid composition (p) without thickening. Therefore, a relatively large amount of resin material can be stably dissolved or dispersed in the liquid composition (p). Furthermore, the liquid composition (p) to which the powder (3) is added is also less likely to deteriorate.

The amounts of powder (1) and powder (2) added to the liquid composition (p) are preferably amounts such that the ratio of the mass of the added polymer to the mass of the resin material is 0.1 to 1, and 0.2 to 1. The amount is more preferably 0.8, and even more preferably 0.3 to 0.7. In this case, the viscosity of the liquid composition (p) can be easily adjusted within a predetermined range. Specifically, the viscosity at 25° C. of the liquid composition (p) to which the powder is added is preferably less than 10,000 mPa·s, more preferably 100 to 5,000 mPa·s, and even more preferably 500 to 4,000 mPa·s.

The amount of powder (3) added to the liquid composition (p) is preferably such that the ratio of the mass of the added polymer to the mass of the resin material is 0.1 to 0.5, and is 0.1 to 0.4. The amount is more preferred. In this case, since the amount of resin material contained in the liquid composition (p) is sufficiently large, excellent physical properties (flame retardancy, processability, etc.) are imparted to the resin layer formed from the liquid composition (3). can.
The viscosity at 25° C. of the liquid composition (p) to which the powder (3) is added is preferably less than 10,000 mPa·s, more preferably 50 to 5,000 mPa·s, and even more preferably 100 to 1,000 mPa·s.

The additive powder in additive (1) preferably has an additive polymer as a main component. The content of the added polymer in the added powder is preferably 80% by mass or more, more preferably 100% by mass. The additive powder may contain the resin material itself. Note that components other than the added polymer in powder (3), such as a surface treatment agent, and the composition of powder (3) will be explained in the description of the method for producing powder (3), which will be described later.
The D50 of powder (1) is preferably 10 to 50 μm, more preferably 12 to 40 μm, and even more preferably 14 to 30 μm. In this range, the powder (1) has particularly excellent dispersibility in the liquid composition (p). In addition, D100 of powder (1) is preferably 100 μm or less.
D100 of powder (2) is preferably 5 μm or less. D100 of powder (2) is preferably 0.3 μm or more, more preferably 1 μm or more. In this range, the powder (2) has particularly excellent dispersibility in the liquid composition (p). Note that the D50 of the powder (2) is preferably 0.1 to 3 μm.
The D50 of powder (3) is less than 25 μm, preferably 10 μm or less, more preferably 0.05 to 8 μm, and even more preferably 0.1 to 6 μm. Moreover, D90 of powder (3) is preferably 40 μm or less, more preferably 15 μm or less. In D50 and D90 within this range, the powder has good fluidity and dispersibility, and the resin layer formed from the powder (3) tends to exhibit good electrical properties (low dielectric constant, etc.) and heat resistance.

The additive powder may be corona treated, plasma treated, electron beam treated or radiation treated.
Corona treatment or plasma treatment can introduce oxygen-containing polar groups (>C(O), -C(O)F, etc.) onto the surface of the additive powder, improving the dispersibility of the additive powder and the surface of the molded product (resin layer). It is easier to improve the adhesion.
On the other hand, electron beam treatment or radiation treatment is thought to partially decompose the added polymer and generate oligomers. In this case, the added powder will contain oligomers derived from the added polymer. Since such an oligomer functions as a dispersant or a plasticizer, it is easier to improve the dispersibility of the additive powder and the processability of the molded article. Furthermore, when forming a molded article from a liquid composition, the gas generated by the decomposition and volatilization of the oligomer roughens the surface of the formed article, resulting in physical (anchor effect) or chemical adhesion of the molded article. It can also be expected to improve sexual performance. Further, it is considered that the additive powder is physically brittle and easily disintegrated due to the electron beam treatment or radiation treatment. Therefore, in the molded product, the added polymer and the resin material are more likely to interact with each other, and physical properties such as flame retardance due to the added polymer are likely to be significantly exhibited.

Powder (1) is preferably produced by subjecting a dispersion containing primary particles of a copolymer of TFE and PAVE obtained by aqueous polymerization to coagulation treatment or freeze-drying treatment. In the powder (1) obtained by such treatment, each particle constituting the powder is an aggregate of primary particles of the added polymer (1), and the bulk density tends to decrease and the dispersibility improves.
Powder (2) is preferably a powder described in, for example, International Publication No. 2016/017801 or International Publication No. 2019/098202.

The additive polymer (1) preferably contains 92 to 98 mol% of TFE units and 2 to 8 mol% of PAVE units based on all units constituting the polymer. The additive polymer (1) may consist only of TFE units and PAVE units, or may further contain other units.
The proportion of TFE units in the added polymer (1) is more preferably 94 mol% or more, and even more preferably 96 mol% or more. The proportion of TFE units is more preferably 97.8 mol% or less, and even more preferably 97.7 mol% or less.
The proportion of PAVE units in the added polymer (1) is more preferably 2.1 mol% or more, and even more preferably 2.3 mol% or more. The proportion of PAVE units is preferably 6 mol% or less, more preferably 4 mol% or less.
When the additive polymer (1) contains other units, the proportion of the other units is preferably 5.9 mol% or less, more preferably 3.7 mol%, and even more preferably 1.7 mol%.

The proportion of TFE units in the added polymer (2) is preferably 94 mol% or more, and preferably 96 mol% or more. The proportion of TFE units is preferably 99 mol% or less, more preferably 98 mol% or less.
The proportion of PAVE units in the added polymer (2) is preferably 1.2 mol% or more, more preferably 1.5 mol% or more. The proportion of PAVE units is preferably 2.7 mol% or less, more preferably 2.4 mol% or less.
The proportion of polar units in the added polymer (2) is preferably 0.01 mol% or more, more preferably 0.05 mol% or more. The proportion of PAVE units is preferably 3 mol% or less, more preferably 1 mol% or less.
The additive polymer (2) may consist only of TFE units, PAVE units, and polar units, or may further contain other units.

PAVE in the additive polymers (1) and (2) is preferably CF ₂ =CFOCF ₃ or CF ₂ =CFOCF ₂ CF ₃ PPVE, from the viewpoint of easy adjustment of the melt viscosity or melting temperature of the additive polymer to the range described below. PPVE is more preferred.
Other units in the added polymers (1) and (2) are preferably HFP units and FAE units. As FAE, _CH2 =CH( _CF2 ) _2F , _CH2 =CH( _CF2 ) _4F , _CH2 =CF( _CF2 ) _2H and _CH2 =CF( _CF2 ) _4H are preferable.

The oxygen-containing polar group contained in the polar monomer in the additive polymer (2) is preferably a hydroxyl group-containing group, a carbonyl group-containing group, an acetal group, or a phosphono group (-OP(O)OH ₂ ), and a carbonyl group-containing group is more preferable. preferable.
As the hydroxyl group-containing group, a group containing an alcoholic hydroxyl group is preferable, and -CF ₂ CH ₂ OH, -C(CF ₃ ) ₂ OH and 1,2-glycol group (-CH(OH)CH ₂ OH) are more preferable. preferable.
The carbonyl group-containing group is a group containing a carbonyl group (>C(O)), and examples of the carbonyl group-containing group include a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC(O)NH ₂ ), acid anhydride residues (-C(O)OC(O)-), imide residues (-C(O)NHC(O)-, etc.) and carbonate groups (-OC(O)O-) are preferred. .
Polar monomers include itaconic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride (NAH), and maleic anhydride.

The melt viscosity of the added polymer at 380° C. is preferably 1×10 ² to 1×10 ⁸ Pa·s, more preferably 1×10 ³ to 1×10 ⁶ Pa·s.
The melting temperature of the added polymer is preferably 200 to 320°C, more preferably 260 to 320°C. In this case, when a substrate with a resin layer is produced, it is easy to further improve the adhesiveness of the resin layer to the substrate.

The added polymer may be fluorine gas treated. By the fluorine gas treatment, a fluorine-containing group such as -CF ₃ is introduced at the end of the polymer chain of the added polymer. This makes it easier to adjust the dispersibility of the added powder. It is also believed that the fluorine gas treatment causes some of the added polymer to be decomposed and oligomers to be produced. In this case, the added powder will contain oligomers derived from the added polymer. Since such an oligomer functions as a dispersant or a plasticizer, it is easier to improve the dispersibility of the additive powder and the processability of the molded article. Furthermore, when forming a molded article from the liquid composition (p), the gas generated by decomposition and volatilization of the oligomer roughens the surface of the formed article, causing physical (anchor effect) or It can also be expected to improve chemical adhesion.

The additive (1) may be used as an additive powder by being added to the liquid composition (p) as a powder, or it may be used by being added to the liquid composition (p) as an additive liquid dispersed in the liquid. You may.
In the latter case, the additive (1) preferably further contains a liquid medium which is a polar solvent, and from the viewpoint of dispersing the additive powder well, the additive (1) is one selected from the group consisting of water, ester, amide, and ketone. It is preferable to contain the above polar solvents. In this case, the content of the additive polymer in the additive liquid is preferably 20 to 50% by mass based on the polar solvent.
The polar solvent can be appropriately selected depending on the type of liquid composition (p).
Examples of esters include ethyl lactate, ethyl acetate, and butyl acetate.
Amides include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.
Examples of ketones include methyl ethyl ketone, methyl isopropyl ketone, cyclopentanone, and cyclohexanone.

Further, it is preferable that the additive liquid further contains a surfactant from the viewpoint of further improving the dispersibility of the additive powder. In this case, the content of the surfactant in the additive liquid is preferably 1 to 10% by mass based on the additive polymer.
The surfactant is not particularly limited as long as it is a compound having a hydrophilic group and a hydrophobic group, and fluorine-based surfactants, silicone-based surfactants, or acetylene-based surfactants are preferable, and fluorine-based surfactants is preferred. Preferably, the surfactant is nonionic.

As the fluorosurfactant, fluoromonol, fluoropolyol, fluorosilicone, and fluoropolyether are preferred.
As the fluoropolyol, a copolymer of a fluoro(meth)acrylate and a (meth)acrylate having a hydroxyl group is preferable, and a (meth)acrylate having a polyfluoroalkyl group or a polyfluoroalkenyl group and a (meth)acrylate having a polyoxyalkylene monool group are preferable. Acrylates are more preferred.
The fluorosilicone is preferably a polyorganosiloxane containing a C—F bond in a part of the side chain.
The fluoropolyether is preferably a compound in which some of the hydrogen atoms of a polyoxyalkylene alkyl ether are substituted with fluorine atoms.

Examples of suitable resin materials for the additive (1) include polyimide aromatic resins, polyamide aromatic resins, polyether aromatic resins, epoxy aromatic resins, polyimide aromatic resins, and polyester aromatic resins. Examples include aromatic resins selected from the group consisting of resins and polycarbonate aromatic resins. These resin materials are preferable because they have excellent various physical properties and have high affinity with added polymers.
A preferred embodiment of the aromatic resin is the same as that in liquid composition (1).

According to the additive (1), a liquid composition (hereinafter also referred to as "liquid composition (2)") containing the aromatic resin and the additive powder can be provided. Liquid composition (2) is a powder dispersion liquid in which additive powder is dispersed in liquid composition (2).
In the liquid composition (2), the ratio of the mass of the added polymer to the mass of the aromatic resin is preferably 0.1 to 1, more preferably 0.2 to 0.8, and 0.3. More preferably, the amount is 0.7.
The liquid composition (2) preferably contains aromatic resin in an amount of 20% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more, based on the total mass of the liquid composition (2). The upper limit thereof is preferably 80% by mass.
The viscosity of the liquid composition (2) is preferably less than 10,000 mPa·s, more preferably 100 to 5,000 mPa·s, and even more preferably 500 to 4,000 mPa·s.

It is preferable that the liquid composition (2) further contains a polar solvent. In this case, the content of the polar solvent in the liquid composition (2) is preferably 20% by mass or more, more preferably 40% by mass or more. The content is preferably 60% by mass or less. Within this range, the viscosity of the resulting liquid composition (2) can be easily adjusted to the above range. As mentioned above, the additive polymer is a hot-melt polymer with high fluidity and has excellent resistance to deterioration against physical stress such as shear force, so even if it contains a polar solvent as a dispersion medium, it will not cause deterioration (increase in quality) of the liquid composition. (viscosity, etc.) can be easily suppressed.

It is preferable that the liquid composition (2) further contains an inorganic filler. By containing an inorganic filler, it is possible to reduce warpage of the resin layer-coated substrate, which will be described later. For example, the linear expansion coefficient (absolute value) of the resin layer-coated substrate is preferably 40° C./ppm or less, more preferably 25° C./ppm or less, and even more preferably 10° C./ppm or less. Such a resin layer-coated substrate with a low coefficient of linear expansion is suitable as a printed wiring board material.
Examples of the inorganic filler include silica, mica, talc, clay, bentonite, montmorillonite, kaolinite, wollastonite, calcium carbonate, titanium oxide, alumina, barium sulfate, potassium titanate, glass, and the like.

The inorganic filler may be in the form of particles or fibers. The specific surface area of the silica particles is preferably 6.5 m ² /g or more, more preferably 6.5 to 1000 m ² /g, even more preferably 10 to 800 m ² /g, and particularly preferably 20 to 700 m ² /g.
The pore volume of the silica particles is preferably 0.05 to 3.0 mL/g, more preferably 0.1 to 2.0 mL/g.
D50 of the silica particles is preferably 0.005 to 100 μm, more preferably 0.02 to 20 μm.
Such silica particles are difficult for the base polymer or additive polymer to penetrate into them, and the effect of forming an air phase in the resin layer also tends to improve the electrical properties of the molded article. Examples of such silica particles include hollow silica particles whose shell portion has a mesoporous structure, hollow silica particles whose shell portion has a nonporous structure, and porous silica particles.

When the liquid composition (2) contains an inorganic filler, the content of the inorganic filler in the liquid composition (2) is preferably 0.1 to 5% by mass, more preferably 0.3 to 1% by mass. In this case, it is easy to obtain a molded product that has a reduced coefficient of linear expansion and also has excellent electrical properties.
The liquid composition (2) of the present invention may further contain agents other than the above-mentioned components. Examples of such agents include agents similar to those in liquid composition (1).

If the liquid composition (2) is applied to the surface of the substrate and heated to form a resin layer, the substrate and the resin layer are laminated in this order to form a resin layer-coated substrate (hereinafter referred to as resin layer-coated substrate (2)). ) is obtained.
The thickness of the substrate is preferably 1 to 30 μm.
As the substrate, copper foils such as rolled copper foils and electrolytic copper foils are preferred. The surface of the substrate may be provided with a rust-preventing layer (such as an oxide film such as chromate), a heat-resistant layer, a roughening treatment layer, and a silane coupling agent treatment layer.
The ten-point average roughness of the surface of the substrate is preferably 0.2 to 2.5 μm. In this case, the peel strength (adhesion) between the substrate and the resin layer is likely to be further improved.
The liquid composition can be applied by spray method, roll coating method, spin coating method, gravure coating method, microgravure coating method, gravure offset method, knife coating method, kiss coating method, bar coating method, die coating method, Fountain Meyer bar method, This can be carried out by a method such as a slot die coating method.
The heating is performed in the same manner as in the resin layer-coated metal plate (1).

In the liquid composition (2), the added polymer (added powder) has high dispersibility, and the added polymer and aromatic resin have high homogeneity in the formed resin layer. The homogeneity of such components can be defined by the ratio of the amounts of fluorine atoms present on both surfaces of the resin layer of the resin layer-coated substrate. Note that the amount of fluorine atoms present on the surface of the polymer layer can be quantified by energy dispersive X-ray analysis.
According to the liquid composition (2), the substrate and the resin layer are laminated in this order, and the resin layer contains an aromatic resin and an additive polymer, and the addition to the mass of the aromatic resin contained in the resin layer is The mass ratio of the polymer is 0.1 to 1, and the ratio of the amount of fluorine atoms present on one surface of the resin layer to the amount of fluorine atoms present on the other surface is 0.8 to 1.2. A resin layer-coated substrate can be provided. The quantitative ratio of fluorine atoms present on both surfaces of the resin layer is preferably 0.9 to 1.1.

The resin layer-coated substrate (2) only needs to have a substrate in contact with at least one surface of the resin layer. Its layer structure is similar to that of the resin layer-coated metal plate (1).
The thickness of the resin layer in the resin layer-coated substrate (2) is preferably 1 to 100 μm.
The resin layer-coated substrate (2) also has high peel strength between the resin layer and the substrate. The peel strength is preferably 7 N/cm or more, more preferably 10 N/cm or more, and even more preferably 13 N/cm or more.

The resin layered substrate (2) is a substrate that includes a resin layer containing an aromatic resin, which is a super engineering plastic, and an additive polymer, and has excellent physical properties such as flame retardancy, electrical properties, and chemical resistance (etching resistance). It is useful as a material for printed wiring boards such as , flexible printed wiring boards, and rigid printed wiring boards.
For example, when the resin layer-coated substrate of the present invention has a metal substrate such as metal foil as a substrate, there may be a method of etching the metal substrate to form a metal conductor wiring (transmission circuit) in a predetermined pattern, or A printed wiring board can be manufactured by processing a metal conductor into a metal conductor wiring by an electrolytic plating method (semi-additive method, modified semi-additive method, etc.).
Therefore, such a printed wiring board has a metal conductor wiring and a resin layer in this order. The aspect of this printed wiring board is similar to the specific aspect of the printed wiring board in the metal plate with resin layer (1).

A preferred embodiment of the resin material in the liquid composition (2) includes non-melting PTFE. The non-melting PTFE may be PTFE (high molecular weight PTFE) having fibril-forming ability, low molecular weight PTFE, or modified PTFE. Note that the low molecular weight PTFE or modified PTFE also includes a copolymer of TFE and a trace amount of a comonomer (HFP, PAVE, FAE, etc.).

Additive (1) is added to a liquid composition containing non-melting PTFE powder and water to obtain a dispersion, and water is further removed from the dispersion to obtain a treated powder.
As mentioned above, the additive polymer contained in additive (1) is a highly fluid hot-melt polymer and has excellent resistance to deterioration due to physical stress such as shearing force, so it can be dispersed even in water, which is a polar solvent. Easy to prepare liquid. Moreover, since the respective powders interact to a high degree in the dispersion, a highly homogeneous dispersion is formed. Therefore, by removing water from such a dispersion, a treated powder is obtained in which the added polymer is highly bound to the non-melting PTFE.
As a method for removing water from the prepared dispersion, a method of freezing the dispersion and removing water by sublimation, or a method of coagulating the dispersion and recovering powder can be adopted.

The additive (1) is added to a liquid composition containing non-melting PTFE powder and a polar solvent to obtain a dispersion, and the dispersion is applied to the surface of a substrate and heated to form a resin layer. Then, a resin layer-attached substrate in which the substrate and the resin layer are laminated in this order is obtained. The resin layer of such a resin layer-coated substrate homogeneously contains a melt-processable additive polymer, and therefore has excellent processability.
As the substrate, the same substrate as the above-mentioned substrate can be used, and metal foil is preferable.
For application of the dispersion liquid, a method similar to the above-mentioned application method can be adopted.
The heating is preferably performed at a temperature equal to or higher than the melting temperature of the added polymer, and more preferably at a temperature at which the non-melting PTFE sinters. Such specific temperatures are 350-380°C.
Other heating conditions may be similar to the heating conditions described above.

This resin-layered substrate is a substrate with a resin layer in which non-melting PTFE and melt-processable additive polymer are highly compatible, and has excellent physical properties such as processability, electrical properties, and chemical resistance (etching resistance). It is excellent and can be processed into printed wiring boards such as flexible printed wiring boards and rigid printed wiring boards.
Alternatively, the resin layer may be recovered as a film (single film) by removing the substrate from this resin layer-coated substrate. The recovered film exhibits good stretching properties, so if it is stretched, it can be used for various functional membrane materials (microfiltration membrane (MF membrane), ultrafiltration membrane (UF membrane), reverse osmosis membrane (RO membrane), It is useful as a membrane material for ion exchange membranes (IE membranes), dialysis membranes (MD membranes), gas separation membranes, etc.

The powder (3) contains an F polymer and a surface treatment agent and has a D50 of less than 25 μm. In the powder (3), the mass ratio of the surface treatment agent to the F polymer contained in the powder is preferably more than 0.01 and less than or equal to 0.25.
The present invention also provides a powder containing an F polymer and a surface treatment agent and having a D50 of less than 25 μm, wherein the mass ratio of the surface treatment agent to the F polymer contained in the powder is more than 0.01 and 0.25 or less. Provides a manufacturing method.
That is, the method for producing a powder of the present invention involves concentrating a powder dispersion containing a raw material powder of F polymer, a surface treatment agent, and a liquid medium, and further separating the liquid medium. This is a method for producing a powder, in which the mass ratio of the surface treatment agent to the F polymer contained in the produced powder is more than 0.01 and less than or equal to 0.25. Hereinafter, this powder manufacturing method will also be referred to as "this method (1)". Moreover, the powder obtained by this method (1) is a powder in which the mass ratio of the surface treatment agent to the F polymer is more than 0.01 and 0.25 or less among the powders (3) as described above.
The F polymer in method (1) is preferably a polymer having a polar functional group, more preferably a polymer having a carbonyl group-containing group, from the viewpoint of enhancing the interaction with the surface treatment agent. Therefore, the F polymer in powder (3) is also preferably a polymer having polar functional groups.

The powder obtained by this method (1) is a powder containing a highly interactive F polymer and a surface treatment agent, and falls under the category of powder (3).
The reason why the powder obtained by the present method (1) has excellent dispersibility in liquid compositions is not necessarily clear, but it is thought to be as follows.

In this method (1), when the powder dispersion containing the raw material powder is concentrated, the interaction between the F polymer and the surface treatment agent is strengthened. It is believed that when the liquid medium is separated from this concentrated powder dispersion, the formation of a powder containing the F polymer and the surface treatment agent is promoted while such interaction is maintained. At this time, if the particle size of the raw material powder is relatively small, for example, if the average particle size of the powder is less than 25 μm, the specific surface area of the raw material powder becomes large, and the interaction between the F polymer and the surface treatment agent becomes synergistic. It is easy to obtain a powder containing a high degree of surface treatment agent.
Note that the interaction between the surface treatment agent and the raw material powder may be a physical interaction that occurs when the surface treatment agent adheres or binds to the surface of the raw material powder, and the interaction between the F polymer of the raw material powder and the surface treatment agent It may also be a chemical interaction caused by chemical bonding.

The D50 of the raw material powder in method (1) is preferably less than 25 μm, more preferably 0.05 to 8 μm. If a raw material powder with a small D50 is used in this way, it is easy to obtain a powder with a D50 of less than 25 μm.
Although the raw material powder may contain resins other than the F polymer, it is preferably composed of the F polymer. The amount of F polymer contained in the powder is preferably 80% by mass or more, more preferably 100% by mass.
Examples of the resin include aromatic polyester, polyamideimide, thermoplastic polyimide, polyphenylene ether, and polyphenylene oxide.

Examples of the surface treatment agent include surfactants, silane coupling agents, hydrophilic agents, etc., with surfactants and silane coupling agents being preferred, and surfactants being more preferred.
A surfactant is a compound having a hydrophilic part and a hydrophobic part, a silane coupling agent is a compound having a silanol group or a hydrolyzable group bonded to a silicon atom, and a hydrophilizing agent is a compound having a hydrophilic part. . Hydrophilic moieties in surfactants and hydrophilizing agents include polyoxyethylene groups, alcohol hydroxyl groups, acetal groups, hemiacetal groups, and the like. Examples of the hydrophobic moiety in the surfactant include fluorinated hydrocarbon groups, long-chain hydrocarbon groups, acetylene groups, and polysiloxane groups. Examples of the hydrophilizing agent include compounds containing polyoxyethylene groups, polyhydroxy compounds, polymers containing acetal groups or hemiacetal groups, and the like.

Specific examples of silane coupling agents include silicon compounds represented by the general formula: R ⁴ _p -Si-(OR ⁵ ) _4-p (wherein R ⁴ is an alkyl group having 1 to 12 carbon atoms, R ⁵ is an alkyl group having 1 to 4 carbon atoms, and p is an integer of 1 to 3.).
Specific examples of compounds containing polyoxyethylene groups include compounds represented by the general formula: H(OCH ₂ CH ₂ ) _m (OR ² ) _n OH (wherein R ² is a carbon atom number of 3 or 4). m and n are each independently an integer of 1 to 5), a compound represented by the general formula: R ³ O(CH ₂ CH ₂ O) _O H (wherein, R ³ is a hydrogen atom or an alkyl group having 10 to 15 carbon atoms, and O represents the average number of moles added and is an integer of 1 to 15.
Specific examples of polyhydroxy compounds include polyvinyl alcohol, polyethylene glycol, polyethylene oxide, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, starch, agarose, and lactose.
Specific examples of polymers containing acetal or hemiacetal groups include terpolymers containing units based on vinyl butyral, units based on vinyl acetate, and units based on vinyl alcohol. Note that the ratio of each unit may be set in consideration of ease of interaction with the F polymer.

Examples of the surfactant include fluorosurfactants, silicone surfactants, and acetylene surfactants. In particular, fluorine-based surfactants are preferred.
Specific examples of fluorine-based surfactants include compounds represented by the general formula: R ^f1 -O-Y (wherein R ^f1 is a polyfluoroalkyl group having 1 to 12 carbon atoms, and Y is -(CH ₂ ) _a OH or -(CH ₂ CH ₂ O) _b (CH ₂ CH(CH ₃ )O) _c H, a is an integer from 1 to 12, and b is an integer from 1 to 20. c is an integer from 0 to 12).

The hydrophobic moiety in the fluorosurfactant is preferably a perfluoroalkyl group, a perfluoroalkyl group having an ether oxygen atom, or a perfluoroalkenyl group.
Suitable embodiments of the fluorosurfactant include polymers each having a perfluoroalkyl group or perfluoroalkenyl group and a polyoxyethylene group or an alcoholic hydroxyl group in their side chains.
Preferably, the polymer is nonionic.
The weight average molecular weight of the polymer is preferably 2,000 to 80,000, more preferably 6,000 to 20,000.
The fluorine content of the polymer is preferably 10 to 60% by weight, more preferably 20 to 50% by weight.
When the polymer has an oxyethylene group, the content of the oxyethylene group in the polymer is preferably 10 to 60% by mass, more preferably 20 to 50% by mass.
When the polymer has an alcoholic hydroxyl group, the hydroxyl value of the polymer is preferably 10 to 300 mgKOH/g.

The perfluoroalkyl group or perfluoroalkenyl group preferably has 4 to 16 carbon atoms. Further, an ether oxygen atom may be inserted between carbon atoms of the perfluoroalkyl group or perfluoroalkenyl group.
The polyoxyethylene group may have an oxyalkylene group having 3 or more carbon atoms. In this case, the oxyethylene group and the oxyalkylene group having 3 or more carbon atoms may be arranged randomly or in blocks.
As the oxyalkylene group having 3 or more carbon atoms, a polyoxypropylene group is preferable.
A preferred specific example of the polymer includes a copolymer of (meth)acrylate having a perfluoroalkyl group or perfluoroalkenyl group and a (meth)acrylate having a polyoxyethylene group or an alcoholic hydroxyl group.

Specific examples of the former (meth)acrylate include _CH2 =C( _CH3 )C(O) _OCH2CH2 ( _CF2 ) _4F , _CH2 = _CHC (O) _OCH2CH2 ( _{CF2 ) 6F} , _CH2 =C( _CH3 )C(O) _OCH2CH2 ( _{CF2 ) 6F} , _CH2 =CHC(O) _OCH2CH2OCF ( _{CF3 )} C(=C( _CF3 ) ₂ )(CF( _CF3 ) ₂ ), _CH2 =C( _CH3 )C(O) _OCH2CH2OCF ( _CF3 )C ₍ =C( _CF3 ) ₂ )(CF( _CF3 ) ₂ ) , _{CH2 =} CHC(O)OCH2CH2CH2CH2OCF( _CF3 )C(=C( _CF3 ) _{2 )} (CF( _CF3 ) ₂ ), _{CH2 =} C( _{CH3 )} C( O) _{OCH2CH2CH2CH2OCF} ( _{CF3 )} C(=C( _CF3 ) ₂ )(CF( _CF3 ) ₂ ) _{, CH2} =C _{( CH3} )C(O _{) CH2CF2} (OCF ₂ ) _f1 ·(OCF ₂ CF ₂ ) _f2 OCF ₃ is given (however, f1 and f2 in the formula are each natural numbers, and the sum thereof is 20).

Specific examples of _the latter (meth) _acrylate include _CH2 =C( _CH3 )C(O) _OCH2CH2OH , _CH2 =C( _CH3 )C( _{O ) OCH2CH2CH2CH2} OH, _CH2 =C( _CH3 )C(O)( _OCH2CH2 ) _{4 OH} , _CH2 =C( _CH3 )C(O)( _{OCH2CH2 ) 9} OH, _CH2 =C(CH ₃ )C(O)( _{OCH2CH2 ) 23OH} , _CH2 =C( _CH3 )C(O)( _{OCH2CH2 ) 9OCH3 , CH2} =C( _CH3 )C(O)( _{OCH2CH2 ) 23 OCH3} , _CH2 =C( _CH3 )C(O)( _OCH2CH2 ) _{66 OCH3 , CH2} =C( _CH3 )C( _O )( _OCH2CH2 ) _{120 OCH3} is mentioned.

Specific examples of fluorine-based surfactants include the "Ftergent" series (manufactured by Neos), the "Surflon" series (manufactured by AGC Seimi Chemical), the "Megafac" series (manufactured by DIC), and the "Unidyne" series (manufactured by DIC). (manufactured by Daikin Industries, Ltd.).

The liquid medium in method (1) may be liquid at 25°C.
Preferably, the liquid medium dissolves the surface treatment agent. That is, the surface treatment agent is preferably soluble in the liquid medium. The solubility (g/100 g of liquid medium) of the surface treatment agent in the liquid medium at 25° C. is preferably 5 or more. The solubility is preferably 30 or less. If the surface treatment agent is soluble in the liquid medium, the interaction between the surface treatment agent and the F polymer during concentration is likely to be further improved.
The liquid medium is preferably an aprotic polar solvent. In this case, the interaction between the surface treatment agent and the F polymer during concentration is likely to be further improved.
The liquid medium is preferably an amide, alcohol, sulfoxide, ester or ketone, more preferably a ketone or amide.

Specific examples of liquid media include water, methanol, ethanol, isopropanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, diethyl ether, dioxane, ethyl lactate, and acetic acid. Examples include ethyl, butyl acetate, methyl ethyl ketone, methyl isopropyl ketone, cyclopentanone, cyclohexanone, ethylene glycol monoisopropyl ether, cellosolve (methyl cellosolve, ethyl cellosolve, etc.). Specific suitable liquid media include methyl ethyl ketone, cyclohexanone, N-methyl-2-pyrrolidone.
Two or more liquid media may be used in combination.

The amount (proportion) of F polymer contained in the powder dispersion in method (1) is preferably 10% by mass or more, more preferably 20 to 50% by mass.
The amount (proportion) of the liquid medium contained in the powder dispersion in method (1) is preferably 15 to 55% by mass, more preferably 25 to 50% by mass.
The amount (proportion) of the surface treatment agent contained in the powder dispersion in method (1) is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass.
Further, in the powder dispersion, the ratio by mass of the amount (ratio) of the surface treatment agent to the amount (ratio) of the F polymer is preferably more than 0.01 and not more than 0.25.
When each component is contained within the above range, the interaction between the F polymer and the surface treatment agent can be sufficiently strengthened, and the powder dispersion can be easily handled, allowing smooth concentration and separation of the liquid medium.

When concentrating the powder dispersion, crystallization of the powder may be accompanied.
Alternatively, the powder dispersion may be subjected to a precipitation treatment to forcibly precipitate the powder. The precipitation treatment may be performed by repeatedly heating and cooling the powder dispersion, for example, by repeatedly heating the powder dispersion to a temperature of 100°C and then cooling it to a temperature of 0°C. In this method, the fluidity of the powder dispersion is increased by heating, making it easier to incorporate the surface treatment agent into the raw material powder, and the raw material powder incorporating the surface treatment agent is easily precipitated in the powder dispersion as a powder by cooling.

The precipitation treatment can also be performed by replacing the liquid medium of the powder dispersion. Specifically, concentration of the powder dispersion and addition of a (high boiling point) poor solvent to the powder dispersion are repeated. In this method, the surface treatment agent is easily incorporated into the raw material powder by replacing the liquid medium with a poor solvent, and the raw material powder incorporating the surface treatment agent is precipitated as a powder in the powder dispersion.
Furthermore, the precipitation treatment can also be performed by salting out the powder dispersion. Specifically, a solute with higher solubility in the liquid medium than the surface treatment agent is added to the powder dispersion to make it easier to incorporate the surface treatment agent into the raw material powder, and the raw material powder incorporating the surface treatment agent is turned into a powder. Can be precipitated in the dispersion.
Note that during the precipitation treatment, F polymer powder may be added to the powder dispersion as a seed crystal.
Note that any two or more of the above precipitation treatments may be combined.

Further, the powder may be forcibly precipitated by performing a powder coagulation treatment on the powder dispersion. Specifically, the powder dispersion to which the coagulant has been added is concentrated and stirred, and the raw material powder incorporating the surface treatment agent is precipitated into the powder dispersion as a powder.
Coagulants include nitric acid, hydrochloric acid, sulfuric acid, magnesium chloride, calcium chloride, sodium chloride, aluminum sulfate, magnesium sulfate, and barium sulfate.
The liquid medium is separated from the powder dispersion in which the powder has precipitated. Methods for separating liquid media include decantation, filtration, and centrifugation. Through this operation, excess surface treatment agent that has not been incorporated into the powder is separated.
The separated powder may be dried, or may be added to a resin-containing liquid described later to produce a liquid composition without drying.

The D50 of powder (3), which is the powder obtained by method (1), is as described above.
The loosely packed bulk density of the powder obtained by this method (1) is more preferably 0.08 to 0.5 g/mL. The densely packed bulk density of the powder obtained by method (1) is more preferably 0.1 to 0.8 g/mL. When the loosely packed bulk density or the tightly packed bulk density is within the above range, the powder has excellent handling properties.
In addition, the mass ratio of the amount of surface treatment agent to the amount of F polymer contained in the powder obtained by this method (1) (mass of surface treatment agent/mass of F polymer) is more than 0.01 and less than or equal to 0.25. Yes, preferably 0.05 to 0.2. In this case, it is easy to produce a liquid composition while preventing deterioration regardless of the particle size.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.
The following materials were used as raw materials.
[F Polymer]
Polymer 1: Copolymer containing 97.9 mol%, 0.1 mol%, and 2.0 mol% of units based on TFE, units based on NAH, and units based on PPVE (melting point 300 ° C.)
Polymer 2: Copolymer containing 97.5 mol% and 2.5 mol% of units based on TFE and units based on PPVE (melting point 300°C)
Polymer 3: Copolymer containing 97.5 mol% and 2.5 mol% of TFE units and PPVE units in this order (melting temperature 305°C)
Polymer 4: Copolymer containing 98.3 mol% and 1.7 mol% of TFE units and PPVE units in this order (melting temperature 305°C)
Polymer 5: A copolymer containing TFE units, NAH units, and PPVE units in this order at 98.0 mol%, 0.1 mol%, and 1.9 mol%, and having a polar functional group (melting temperature 300°C)
Polymer 6: A copolymer containing TFE units and PPVE units in this order at 98.7 mol% and 1.3 mol% and having no polar functional groups (melting temperature 305°C)

[F powder]
Powder 1: Powder consisting of Polymer 1 and having D50 of 26.4 μm Powder 2: Powder consisting of Polymer 2 and having D50 of 18.8 μm Powder 3: Powder consisting of Polymer 2 and having D50 of 2.3 μm Powder 4: Polymer 2 Powder 5: Powder consisting of Polymer 1, having D50 of 1.7 μm and D100 of 4.9 μm.
Powder 6: Powder made of polymer 3 and having D50 of 18.8 μm Powder 7: Powder made of polymer 4 and having D50 of 17.5 μm Powder 8: Powder made of polymer 3 and having D50 of 6.4 μm and D100 of 7.9 μm Powder 9: Powder made of Polymer 1, with D50 of 1.5 μm and D100 of 4.6 μm Powder 10: Powder made of Polymer 5, with D50 of 2.0 μm and D90 of 5.2 μm Powder 11: Polymer 6 Powder with D50 of 2.1 μm and D90 of 5.5 μm. Powder 9 was the same as Example 1 of International Publication No. 2019/098202, except that the rotation speed of the high-efficiency precision air classifier was changed to 5000 rpm. Produced in the same manner as the powder described. Further, D100 of powders 6, 7, and 8 is each 100 μm or less.

[Liquid medium]
MEK: Methyl ethyl ketone NMP: N-methyl-2-pyrrolidone [Raw material composition]
Raw material composition 1: A thermosetting resin containing a precursor of a polyphenylene ether resin and a curing agent, and further containing methyl ethyl ketone and having an aromatic resin content (hereinafter also referred to as "WAr") of 10% by mass or more. Liquid Composition Raw Material Composition 2: A thermosetting liquid composition containing a polyphenylene ether resin precursor and a curing agent, and further containing methyl ethyl ketone and having a WAr content of less than 10% by mass Raw Material Composition 3: 3,3' NMP solution of polyimide aromatic resin precursor 1 containing 4,4'-biphenyltetracarboxylic dianhydride (BPDA), p-phenylenediamine (PPD), and a curing agent (total mass of precursor 1: 25 mass%)
Raw material composition 4: 3,4,3',4'-benzophenonetetracarboxylic dianhydride, 2,4-diaminotoluene, and 3,4,3',4'-biphenyltetracarboxylic dianhydride. , 2,2-bis{4-(4-aminophenoxy)phenyl}propane block copolymer (molar ratio 1:1:1:1) in NMP solution (solid content 10% by mass)

[Surface treatment agent]
Surface treatment agent 1: A methacrylate polymer having a perfluoroalkyl group, a polyoxyalkylene group, and an alcoholic hydroxyl group in the side chains (fluorine content: 35% by mass, hydroxyl value: 19mgKOH). Note that the surface treatment agent 1 is a nonionic fluorosurfactant soluble in MEK.
[Metal plate]
Copper foil 1: Ultra-low roughness electrolytic copper foil (manufactured by Fukuda Metal Foil and Powder Industries Co., Ltd., CF-T4X-SV, thickness: 18 μm, Rzjis: 1.2 μm)

[Example 1] Manufacturing/evaluation example (Part 1)
[Example 1-1] Production example of liquid composition (Liquid composition 1)
A horizontal ball mill container was filled with raw material composition 1, and then powder 1 was added and mixed using a stirring blade to obtain liquid composition 1 in which powder 1 was dispersed (containing aromatic resin). Ratio (hereinafter also referred to as "WAr"): 10% by mass or more, content ratio of F polymer to aromatic resin content (hereinafter also referred to as "WF/WAr"): 0.3).
In addition, liquid composition 1 had a viscosity of 800 mPa·s, and the powder did not settle even after being left at 25° C. for 3 days.

(Liquid composition 2)
A horizontal ball mill container was filled with raw material composition 1, and then a blended powder of powder 1 and powder 5 was added and mixed using a stirring blade to obtain liquid composition 2 (WAr: 10 mass % or more, WF/WAr: 0.3).
Note that the blended powder contains 1 part by mass of Powder 5 to 5 parts by mass of Powder 1.
In addition, liquid composition 2 had a viscosity of 1300 mPa·s, and the powder did not settle even after being left at 25° C. for 3 days.

(Liquid compositions 3 to 7)
Liquid compositions 3 to 7 were obtained in the same manner as liquid composition 1, except that the types and mixing ratios of the powder and raw material compositions were changed as shown in Table 1.
In addition, when trying to increase the WAr value of the liquid compositions by heating the liquid compositions 6 and 7 and distilling off the liquid medium, the viscosity increased significantly and stable liquid compositions could not be obtained.
The formulations and properties of liquid compositions 1 to 7 are summarized in Table 1.

[Example 1-2] Prepreg manufacturing example (Prepreg 1)
An opened glass cloth (average thickness 14 μm) treated with 3-aminopropylmethyldimethoxysilane was immersed in liquid composition 1. The soaked product was heated at 150° C. for 10 minutes to obtain prepreg 1.
(Prepreg 2 to Prepreg 7)
Prepregs 2 to 7 were obtained in the same manner except that liquid compositions 2 to 7 were used instead of liquid composition 1.

[Example 1-3] Production example and evaluation example of metal foil with resin (metal plate with resin layer) (Metal foil with resin 1)
A laminate of copper foil 1 and prepreg 1 is stacked and vacuum hot pressed under hot press conditions of 185° C., pressure 3.0 MPa, and 60 minutes to form a solidified layer (liquid) of copper foil 1 and prepreg 1. A resin-coated metal foil 1 having a resin layer consisting of a dried product of Composition 1) in this order was obtained.
The resin-coated metal foil 1 has a peel strength of 10 N/cm between the copper foil 1 and the resin layer, and has a peel strength of 10 N/cm even when subjected to a solder reflow test (a test in which the resin-coated metal foil is floated on solder at 288°C 5 times for 5 seconds). , a phenomenon in which the copper foil 1 rose from the resin layer (peeling phenomenon) did not occur.
Further, the relative dielectric constant (measurement frequency: 20 GHz) of the resin layer was 3.05 or less, and the dielectric loss tangent was 0.016 or less.
(Metal foil with resin 2 to metal foil with resin 7)
Resin-coated metal foils 2 to 7 were produced and evaluated in the same manner except that prepregs 2 to 7 were used in place of prepreg 1.
The above results are summarized in Table 1.

As is clear from the above results, in the example of liquid composition 4 using Powder 3 with a small average particle size of F powder, the resin-coated metal foil with excellent physical properties was deteriorated due to a significant decrease in viscosity and dispersion stability. I couldn't get it.
In addition, in the example of liquid composition 5 using Powder 4 having a large average particle size of F powder, the homogeneity of the F polymer in the resin layer was impaired, making it impossible to obtain a resin-coated metal foil with excellent electrical properties. Ta.
Furthermore, in the examples of liquid compositions 6 and 7 with low WAr values, the amount of resin component retained in the prepreg was insufficient, and resin-coated metal foils with excellent electrical properties could not be obtained.

[Example 2] Manufacturing/evaluation example (Part 2)
[Example 2-1] Preparation of liquid composition (Liquid composition 8)
A horizontal ball mill container is filled with 100 parts by mass of raw material composition 3, then 5 parts by mass of powder 6 is added and mixed using a 15 mm diameter zirconia ball to obtain a liquid composition in which powder 6 is dispersed. I got item 8. WAr (content of precursor 1) in liquid composition 8 is 24% by mass, and WF/WAr is 0.2.

(Liquid composition 9)
Liquid composition 9 was prepared in the same manner as liquid composition 8 except that the amount of powder 6 added was 30 parts by mass.
(Liquid composition 10)
Liquid composition 10 was prepared in the same manner as liquid composition 8 except that powder 6 was changed to powder 7.
(Liquid composition 11)
Liquid composition 11 was prepared in the same manner as liquid composition 8 except that powder 6 was changed to powder 8.
(Liquid composition 12)
Liquid composition 12 was prepared in the same manner as liquid composition 8 except that powder 6 was changed to powder 9.

<Dispersibility evaluation of liquid composition>
The dispersion stability of each of liquid compositions 8 to 12 was confirmed and evaluated according to the following criteria.
Excellent: No sediment even after standing at 25°C for 3 days.
Acceptable: Sediment is present when left at 25°C for 3 days.

<Homogeneity evaluation of resin layer>
Each of liquid compositions 8 to 12 was applied to the surface of copper foil (thickness 12 μm) using a bar coater, and heated and dried in a drying oven at 180 ° C. for 30 minutes. A resin layer (dry film, thickness 20 μm) was formed to obtain a copper foil with a resin layer in which the copper foil and the resin layer were laminated in this order. The copper foil of the resin-layered copper foil was etched with a ferric chloride aqueous solution, and a single resin layer was recovered. Each surface of the collected resin layer was analyzed to measure the amount of fluorine atoms [mass%] on each surface. Based on the measured values, the ratio of fluorine atoms present on both surfaces was determined and evaluated according to the following criteria.
Excellent: 1.0 or more, 1.2 or less Good: More than 1.2, 1.6 or less Poor: More than 1.6

<Flame retardant evaluation of resin layer>
The resin layer recovered above was subjected to a combustion test in accordance with the UL94 test method and evaluated as "non-flammable (V-0)" and "flammable".
The above results are summarized in Table 2.

Furthermore, the surfaces of the resin layers of the resin-layered copper foils obtained in Liquid Composition 8 and Example 12 had excellent surface smoothness with no visible bumps or stripes.
Even if a solvent-soluble liquid crystalline polyester resin or polyphenylene ether resin is used instead of the polyimide aromatic resin or its precursor, the same results as above can be obtained.

[Example 3] Manufacturing/evaluation example (Part 3)
[Example 3-1] Preparation of modified powder The mass ratio of the amount of surface treatment agent to the amount of F polymer contained in the modified powder obtained below is determined by the mass of F polymer added to the powder dispersion used and the surface It was determined by measuring the mass of the treatment agent, the mass of F polymer contained in the filtrate obtained by filtering the powder dispersion, and the mass of the surface treatment agent.
(Modified powder 1)
First, a powder dispersion containing 35 parts by mass of Powder 10, 5 parts by mass of Surface Treatment Agent 1, and 60 parts by mass of MEK was prepared. This powder dispersion was concentrated under reduced pressure to remove 30 parts by mass of MEK, and then filtered. Next, the obtained filter residue was vacuum dried at 25° C. to obtain modified powder 1 (mass of surface treatment agent 1/mass of polymer 5 = 0.12).

(Modified powder 2)
Modified powder 2 (mass of surface treatment agent 1/mass of polymer 6 = 0.04) was obtained in the same manner except that powder 11 was used instead of powder 10.
(Modified powder 3)
Modified powder 3 (mass of surface treatment agent 1/mass of polymer 6 = less than 0.01) was prepared in the same manner except that powder 11 was used instead of powder 10 and the powder dispersion was subjected to homogenization treatment instead of vacuum concentration. ) was obtained.

<Storage stability of powder>
Each modified powder was dispersed in toluene to prepare a dispersion liquid for evaluation. This evaluation dispersion was stored at a temperature of 5° C. for one week and evaluated according to the following criteria.
[Evaluation criteria]
○ (Excellent): The powder was uniformly dispersed in the evaluation dispersion, or even if it precipitated, it was easily redispersed by simply shaking it by hand.
Δ (Good): Powder sedimented in the evaluation dispersion liquid, and application of ultrasonic waves was required for redispersion.
× (impossible): The powder precipitated in the evaluation dispersion liquid and could not be redispersed even when ultrasonic waves were applied.
As a result, the modified powder 1 was rated "○", the modified powder 2 was rated "Δ", and the modified powder 3 was rated "x".

[Example 3-2] Preparation of liquid composition (liquid composition)
Modified powder 1 was directly added to raw material composition 4 to prepare liquid composition 13. Note that the mass of powder 1 of polymer 6/mass of polyimide resin was 25 parts by mass/75 parts by mass (WF/WAr: 0.33, WAr: more than 10% by mass).
(Example 2-2)
A liquid composition 14 was obtained in the same manner except that modified powder 1 was changed to powder 10.

<Thickening rate of liquid composition>
The thickening rate of each liquid composition relative to the polyimide resin varnish was measured and evaluated according to the following criteria.
[Evaluation criteria]
○ (Excellent): The thickening rate was 100% or less.
× (impossible): The thickening rate was more than 100%.
As a result, liquid composition 13 was rated "○", and liquid composition 14 was rated "x".

<Manufacture of printed wiring boards>
First, a resin-containing liquid containing a polyphenylene ether resin precursor, a crosslinking agent, and MEK was prepared. The total amount of the polyphenylene ether resin precursor and crosslinking agent contained in this resin-containing liquid was 10% by mass or more.
Next, after filling a resin-containing liquid into a horizontal ball mill container, the above powder 1 was added and mixed using a stirring blade. Thereby, a liquid composition 15 (viscosity: 1000 mPa·s or less) in which the powder 10 was dispersed was obtained.
Next, the liquid composition 15 was applied roll-to-roll by a gravure reverse method onto the surface of a copper foil having a thickness of 18 μm to form a liquid film. Next, the copper foil on which the liquid film was formed was passed through a drying oven at 120° C. for 5 minutes and dried by heating. The dried film was then heated at 380° C. for 3 minutes in a far-infrared oven under a nitrogen atmosphere. In this way, a resin-coated copper foil in which a resin layer was formed on the surface of the copper foil was manufactured. Note that the thickness of the resin layer was 8 μm.
When resin-coated copper foil is processed into a transmission circuit (circuit pattern) having a predetermined shape by etching, a printed wiring board with excellent physical properties such as electrical properties and peel strength can be obtained.

The liquid composition of the present invention is suitable for forming a prepreg in which a fiber base material is impregnated with a resin component at a high concentration and a thick insulating resin layer with high component homogeneity, and is suitable for forming antennas with excellent electrical properties and heat resistance. It is useful as a material for parts, printed wiring boards (flexible printed wiring boards, rigid printed wiring boards), coverlay films, solder resists, insulating layers for power semiconductors, aircraft parts, and automobile parts.
The powder of the present invention can be used as a component of a liquid composition for use in coated articles such as antenna parts, printed wiring boards, aircraft parts, automobile parts, sports equipment, food industry products, saws, and plain bearings. can. In addition, printed wiring boards are useful as substrates for electronic devices such as radars, network routers, backplanes, and wireless infrastructure that require high frequency characteristics, substrates for various automotive sensors, and substrates for engine management sensors. It is suitable for applications aimed at reducing transmission loss in the millimeter wave band and improving flame retardancy.
In addition, Japanese Patent Application No. 2019-044624 filed on March 12, 2019, Japanese Patent Application No. 2019-044627 filed on March 12, 2019, and Japanese Patent Application No. 2019-044627 filed on March 12, 2019. The entire contents of the specification, claims, and abstract of Application No. 2019-096837 and Japanese Patent Application No. 2019-125278 filed on July 4, 2019 are cited here, and the disclosure of the specification of the present invention is It should be taken in as such.

Claims (9)

A liquid composition comprising the following powder (1) of a heat-melting tetrafluoroethylene polymer, an aromatic resin, and a liquid medium, the content of the aromatic resin being 10% by mass or more, the aromatic resin A liquid composition in which the ratio of the content of the tetrafluoroethylene polymer to the content of is 1.2 or less, and the viscosity at 25° C. is 10,000 mPa·s or less.
Powder (1): A powder of a heat-melting tetrafluoroethylene polymer containing 92 to 98 mol% of units based on tetrafluoroethylene and 2 to 8 mol% of units based on perfluoro(alkyl vinyl ether), the volume of which is Powder with a standard cumulative 50% diameter of 10 to 60 μm The liquid composition according to claim 1, wherein the ratio of the content ratio of the tetrafluoroethylene polymer to the content ratio of the aromatic resin is 0.1 to 0.5. The aromatic resin is aromatic polyimide resin, aromatic polycarbonate resin, aromatic polyamide resin, aromatic polyester resin, aromatic polyether sulfone resin, aromatic maleimide resin, polyphenylene ether resin, polyphenylene sulfide resin, and aromatic epoxy resin. The liquid composition according to claim 1 or 2, which is an aromatic resin selected from the group consisting of: or a precursor thereof. The liquid composition according to any one of claims 1 to 3, wherein the liquid composition has a viscosity at 25° C. of 100 to 5000 mPa·s. The liquid composition according to any one of claims 1 to 4 , wherein the volume-based cumulative 50% diameter of the powder (1) is 16 to 40 μm. The powder (1) includes a first powder having a volume-based cumulative 50% diameter of 8 μm or less and a second powder having a volume-based cumulative 50% diameter of 16 to 40 μm, The liquid composition according to any one of claims 1 to 5 , which is a powder with a powder content ratio of 0.5 or less. A method for producing a prepreg comprising a dried product of the liquid composition and the fiber base material, the method comprising impregnating a fiber base material with the liquid composition according to any one of claims 1 to 6 and drying the composition. The liquid composition according to any one of claims 1 to 6 is applied to the surface of a metal plate and heated to form a resin layer containing a dried product of the liquid composition, thereby bonding the metal plate and the A method for manufacturing a resin layer-coated metal plate, which obtains a resin-layer-coated metal plate having a resin layer. 92 to 98 units based on tetrafluoroethylene are added to a liquid composition containing a liquid medium and at least one resin material selected from the group consisting of non-melting tetrafluoroethylene polymers and aromatic resins. A powder of a heat-melting tetrafluoroethylene polymer containing 2 to 8 mol % of perfluoro(alkyl vinyl ether)-based units, the powder having a volume-based cumulative 50% diameter of 10 to 60 μm.