TWI824049B - Dispersions - Google Patents

Abstract

The present invention provides a dispersion liquid in which a powder containing a tetrafluoroethylene polymer is dispersed in a polar solvent and has excellent dispersibility and layer (coating film) formation properties. The dispersion liquid of the present invention contains a powder containing a tetrafluoroethylene polymer, a polar solvent and a dispersant, and the above powder is dispersed in the above polar solvent, and the above dispersant is the following polymer: a polymer based on a monomer having a fluoroalkyl group. The unit of the monomer and the unit based on the monomer having an oxyalkylene glycol group, the fluorine content, the oxyalkylene group content and the hydroxyl value are in the order of 10 to 50 mass%, 5 to 75 mass%, and 10 to 100 mgKOH/ g.

Description

Dispersions

The present invention relates to a dispersion liquid in which a powder containing a tetrafluoroethylene polymer is dispersed in a polar solvent.

Tetrafluoroethylene-based polymers such as polytetrafluoroethylene (PTFE) have excellent physical properties such as chemical resistance, water and oil repellency, heat resistance, and electrical properties, and are known to be available in various forms such as powders, dispersions, and films. Usage forms, and various uses that utilize its physical properties. In recent years, tetrafluoroethylene-based polymers have attracted attention as a printed circuit board material that can cope with high-frequency frequencies and has excellent electrical properties such as low dielectric constant and low dielectric loss tangent, as well as heat resistance that can withstand reflow. Patent Document 1 describes a method of producing a printed circuit board by forming a transmission line on the metal foil with a resin and having a PTFE layer formed of a dispersion liquid in which PTFE powder is dispersed in a solvent. Patent Document 2 describes a dispersion containing a powder of PTFE as the dispersion. Prior technical literature patent documents

Patent Document 1: Japanese Patent Publication No. 2015-509113 Patent Document 2: International Publication No. 2016/159102

Invent the problem you want to solve

Tetrafluoroethylene polymers inherently have low surface tension and low interaction with other materials, so their powder dispersions have low dispersion. There is known a method of blending a fluorine-based dispersant into a dispersion liquid in order to improve the dispersion, but the effect is sometimes insufficient. Furthermore, if the layer (coating film) containing the tetrafluoroethylene polymer formed from the dispersion liquid contains a fluorine-based dispersant, the physical properties (wettability, adhesion, smoothness, etc.) of the layer (coating film) will be affected Sometimes it goes down. The present inventors have found that when the dispersion medium of the dispersion liquid is a polar solvent, the above-mentioned decrease in dispersibility and layer (coating film) formability tends to become significant. There is a demand for a dispersion containing a tetrafluoroethylene polymer powder that uses a polar solvent as a dispersion medium and has dispersibility and layer (coating film) formation properties. Technical means to solve problems

The present invention has the following aspects. <1> A dispersion liquid containing a powder containing a tetrafluoroethylene-based polymer, a polar solvent and a dispersant, wherein the powder is dispersed in the polar solvent, and the dispersant is a polymer containing a fluoroalkane-based polymer The monomer unit of the base and the unit based on the monomer having an oxyalkylene glycol group, the fluorine content, the oxyalkylene group content and the hydroxyl value are in order 10 to 50 mass %, 5 to 75 mass %, 10 to 100 mgKOH/g. <2> The dispersion liquid of the above <1>, wherein the above-mentioned monosystem having a fluoroalkyl group is a compound represented by the following formula F, Formula F: CH ₂ =CX ^F C(O)OQ ^F -R ^F (wherein ^{, _ _} atoms of polyfluoroalkyl). <3> The dispersion liquid of the above <1> or <2>, wherein the above-mentioned monosystem having an oxyalkylene glycol group is a compound represented by the following formula H, formula H: CH ₂ =CX ^H C(O) -(OZ ^H ) _m -OH (in the formula, X ^H represents a hydrogen atom or a methyl group, Z ^H represents an alkylene group having 1 to 4 carbon atoms, and m is 3 to 200). <4> The dispersion liquid according to any one of the above <1> to <3>, wherein the above-mentioned monomer having a fluoroalkyl group is a compound represented by the following formula F1, and the above-mentioned monomer having an oxyalkylene glycol group It is a compound represented by the following formula H1, Formula F1: CH ₂ =CX ^F1 C(O)O-CH ₂ CH ₂ -R ^F1 Formula H1: CH ₂ =CX ^H1 C(O)-(OCH ₂ CH ₂ ) _m1 -OH (in the formula, X ^F1 represents a hydrogen atom or a methyl group, R ^F1 represents -(CF ₂ ) ₄ F or -(CF ₂ ) ₆ F, X ^H1 represents a hydrogen atom or a methyl group, and m1 is 9 to 70). <5> The dispersion liquid according to any one of the above <1> to <4>, wherein the fluorine content of the polymer is 20 to 40% by mass. <6> The dispersion liquid according to any one of the above <1> to <5>, wherein the polymer has an oxyalkylene group content of 20 to 50% by mass. <7> The dispersion liquid according to any one of the above <1> to <6>, wherein the hydroxyl value of the above polymer is 10 to 45 mgKOH/g. <8> The dispersion liquid according to any one of the above <1> to <7>, wherein the above-mentioned polymer contains 60 to 90 mol% of the above-mentioned base having a fluoroalkyl group relative to all units contained in the polymer. The single unit. <9> The dispersion liquid according to any one of the above <1> to <8>, wherein the above-mentioned polymer contains 10 to 40 mol% of the above-mentioned base having an oxyalkane relative to all the units contained in the polymer. Diol-based monomer unit. <10> The dispersion liquid according to any one of the above <1> to <9>, wherein the above-mentioned polymer contains a total of 90 to 100 mol% of the above-mentioned fluorine-based monomer with respect to all units contained in the polymer. The unit is the same as the above-mentioned unit based on the monomer having an oxyalkylene glycol group. <11> The dispersion liquid according to any one of the above <1> to <10>, wherein the polar solvent is water, ketone, ester or amide. <12> The dispersion liquid according to any one of the above <1> to <11>, wherein the polar solvent is methyl ethyl ketone, cyclohexanone, γ-butyrolactone, or 3-methoxy-N,N -Dimethylpropamide or N-methyl-2-pyrrolidinone. <13> The dispersion liquid according to any one of the above <1> to <12>, wherein the cumulative 50% particle diameter of the powder on a volume basis is 0.05 to 6 μm. <14> The dispersion liquid according to any one of the above <1> to <13>, wherein the content of the tetrafluoroethylene-based polymer is 5 to 60 mass %. <15> The dispersion liquid according to any one of the above <1> to <14>, wherein a ratio of the content of the dispersant to the content of the tetrafluoroethylene polymer is 0.25 or less. Effect of invention

According to the present invention, there is provided a dispersion containing a powder of a tetrafluoroethylene polymer that is excellent in layer (coating film) formation properties such as dispersibility, wettability, adhesion, thixotropy, and smoothness. The layer (coating film) formed from the dispersion of the present invention is particularly excellent in wettability and adhesion. The dispersion of the present invention can be favorably used to produce resin-coated metal foils useful as materials for printed circuit boards.

The following terms have the following meanings. "D50 of powder": Use laser diffraction and scattering methods to measure the particle size distribution of powder, set the total volume of the cluster of particles constituting the powder (hereinafter also referred to as "powder particles") to 100%, and obtain the accumulation curve , the particle diameter at the point on the accumulation curve where the cumulative volume reaches 50% (volume-based cumulative 50% particle diameter). "Powder D90": Use laser diffraction and scattering methods to measure the particle size distribution of the powder. Set the total volume of the powder particle cluster to 100% and calculate the cumulative curve. The point on the cumulative curve where the cumulative volume reaches 90% Particle size (cumulative 90% particle size on a volume basis). That is, the D50 and D90 of the powder are respectively the volume-based cumulative 50% particle size and the volume-based cumulative 90% particle size. "Melt viscosity of polymer": According to ASTM D 1238, use a rheometer and a 2ϕ-8L die to make a sample (2 g) of the polymer that has been heated at the measured temperature for 5 minutes under a load of 0.7 MPa The value obtained is measured while maintaining the measurement temperature. "Viscosity": The value measured using a B-type viscometer at room temperature (25°C) and a rotation speed of 30 rpm. Repeat the measurement three times and take the average of the three measured values. "Ten-point average roughness (Rz _JIS )": The value specified in the appendix JA of JIS B 0601:2013. The "unit" in a polymer can be an atomic group formed directly from a monomer through a polymerization reaction, or it can be an atomic group after a specific method is used to process the polymer obtained through the polymerization reaction, so that part of the structure is transformed. "(Meth)acryloxy" is a general term for acryloxy and methacryloxy. "(Meth)acrylate" is the general term for acrylate and methacrylate. The so-called "units" in polymers refer to atomic groups based on the above monomers formed by the polymerization of monomers. The units may be directly formed by polymerization reaction, or may be converted into other structures by processing the polymer so that part of the above-mentioned units is converted. Hereinafter, units based on monomer a will also be abbreviated as "monomer a unit". For example, units based on tetrafluoroethylene (TFE) are also abbreviated as "TFE units".

The dispersion liquid of the present invention contains a powder containing a tetrafluoroethylene polymer (hereinafter also referred to as "F polymer"), a polar solvent and a dispersant, and the powder is dispersed in the polar solvent. The dispersant contains a unit based on a monomer having a fluoroalkyl group (hereinafter, also referred to as "monomer F") and a unit based on a monomer having an oxyalkylene glycol group (hereinafter, also referred to as "monomer AO"). ) unit polymer (hereinafter also referred to as "AO polymer"). The fluorine content, oxygen alkylene content and hydroxyl value of the AO polymer are in order 10-50 mass%, 5-75 mass%, and 10-100 mgKOH/g. In addition, the so-called oxyalkylene glycol group refers to a group represented by an oxyalkylene glycol residue (formula - (OZ) _n -OH), etc. In the formula, Z represents an alkylene group, and n represents 2 or more. number).

The dispersion of the present invention not only has excellent dispersibility, but also has excellent layer (coating film) formation properties such as wettability, adhesiveness, thixotropy, and smoothness. The reason is considered to be that the AO polymer used as the dispersant has a fluorine-containing moiety, a hydroxyl group, and a polyoxyalkylene group moiety, and its hydroxyl value, fluorine content, and oxyalkylene group content are each adjusted to the above-mentioned specific ranges. The hydroxyl value and oxygen alkylene content of the AO polymer have a trade-off relationship with the fluorine content. It is not easy to adjust each value to maintain a balance between the affinity for the F polymer and the affinity for the polar solvent. That is, the fluorine content of the AO polymer is derived from the structure (fluorine content) of the monomer F and the amount of the monomer F unit in the polymer, and the hydroxyl value and oxyalkylene content of the AO polymer are derived from the structure of the monomer AO. and the amount of monomer AO units in the polymer.

For example, if monomer F with a higher fluorine content is selected and its content is increased, an AO polymer with a higher fluorine content can be prepared. However, the affinity of the above-mentioned AO polymer with the F polymer is improved. On the contrary, since its hydroxyl value and oxygen alkylene group content are relatively reduced, the affinity with polar solvents is reduced. As a result, the dispersibility of the dispersion liquid containing the above-mentioned AO polymer decreases. After painstaking research, the inventors found that if the structure of monomer F and the structure of monomer AO are selected separately, and the fluorine content, hydroxyl value and oxygen alkylene content of the AO polymer are adjusted to the above-mentioned specific values, If the dispersant is within the specified range, the dispersibility of the dispersion will be improved. Furthermore, they discovered that the layer (coating film) formed from the said dispersion liquid has excellent physical properties, and completed this invention.

The powder in the present invention preferably contains F polymer as the main component. The content of the F polymer in the powder is preferably 80% by mass or more, particularly preferably 100% by mass. Examples of other resins that may be contained in the powder include aromatic polyester, polyamide imide, thermoplastic polyimide, polyphenylene ether, polyoxyxylene, and the like.

The D50 of the powder is preferably 0.05-6 μm, particularly preferably 0.1-3 μm. When the D50 of the powder is in the above range, the fluidity and dispersibility of the powder are improved, and the surface smoothness of the coating film or layer (hereinafter also referred to as "F layer") formed from the dispersion liquid of the present invention is excellent. The D90 of the powder is preferably 8 μm or less, and particularly preferably 1.5 to 5 μm. When the D90 of the powder is in the above range, the dispersibility of the powder and the homogeneity of the F layer are excellent. The loose bulk density and tap density of the powder are preferably 0.08 to 0.5 g/mL and 0.1 to 0.8 g/mL in that order.

The F polymer in the present invention is a polymer containing units based on TFE (TFE units). The F polymer is preferably a homopolymer containing a TFE unit (hereinafter also referred to as "PTFE") or a copolymer containing a TFE unit and a unit based on perfluoro(alkyl vinyl ether) (PAVE) (PAVE unit) (hereinafter, also referred to as "PFA"), a copolymer including a TFE unit and a unit based on hexafluoropropylene (HFP) (hereinafter, also referred to as "FEP") (hereinafter, also referred to as "FEP"), or a copolymer including a TFE unit and a fluoroalkane-based unit. Copolymer of ethylene (FAE) units (FAE units). PTFE also includes low molecular weight polymers or polymers containing units other than TFE units in very small amounts. The above-mentioned polymer preferably contains 99.5 mol% or more of TFE units, particularly preferably 99.9 mol% or more, based on all the units contained in the polymer. Moreover, the melt viscosity of the above-mentioned polymer at 380°C is preferably 1×10 ² to 1×10 ⁸ Pa·s, particularly preferably 1×10 ³ to 1×10 ⁶ Pa·s.

The low molecular weight PTFE may be PTFE obtained by irradiating high molecular weight PTFE with radiation (polymers described in International Publication No. 2018/026012, International Publication No. 2018/026017, etc.), or may be obtained by polymerizing TFE. PTFE obtained using a chain transfer agent (polymers described in Japanese Patent Laid-Open No. 2009-1745, International Publication No. 2010/114033, Japanese Patent Laid-Open No. 2015-232082, etc.) may also be a core-containing polymer. PTFE has a shell structure and only the shell part is low molecular weight PTFE (a polymer described in Japanese Patent Application Publication No. 2005-527652, International Publication No. 2016/170918, Japanese Patent Application Publication No. 09-087334, etc.). The standard specific gravity of low molecular weight PTFE (specific gravity measured according to ASTM D4895-04) is preferably 2.14 to 2.22, more preferably 2.16 to 2.20.

F polymers also include polymers containing units other than TFE units. The above-mentioned polymer preferably contains more than 0.5 mol % of monomer-based units other than TFE units relative to the total units of the polymer. Units other than TFE are preferably PAVE units, HFP units, FAE units or units having functional groups described below. The F polymer preferably has at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group, an oxetanyl group, an amine group, a nitrile group, and an isocyanate group. When the F polymer has the above-mentioned functional groups, the interaction between the hydroxyl group and the oxygen alkylene group contained in the AO polymer and the F polymer tends to become stronger, resulting in poor dispersion properties and layer (coating film) formation properties. can be further improved. Furthermore, the carbonyl group-containing group includes a amide group.

The above-mentioned functional groups may be included in the units constituting the F polymer, or may be included in the terminal groups of the polymer main chain, or may be introduced into the F polymer through plasma treatment or the like. Examples of the F polymer containing the above-mentioned functional group in the terminal group of the polymer main chain include F polymers having functional groups as terminal groups derived from polymerization initiators, chain transfer agents, and the like. The above-mentioned functional group is preferably a hydroxyl group or a carbonyl-containing group, particularly preferably a carbonate group, a carboxyl group, a haloformyl group, an alkoxycarbonyl group or an acid anhydride residue (-C(O)OC(O)-), and the most preferred is Carboxyl or anhydride residue. The F polymer is preferably a polymer containing TFE units, PAVE units, HFP units or FAE units, and units with functional groups.

The unit having a functional group is preferably a unit based on a monomer having a functional group. The monomer having a functional group is preferably a monomer having a hydroxyl group or a carbonyl group-containing group, more preferably a monomer having an acid anhydride residue or a monomer having a carboxyl group, and particularly preferably a cyclic monomer having an acid anhydride residue. body. Examples of the cyclic monomer include: itaconic anhydride, citraconic anhydride, 5-norbis-2,3-dicarboxylic anhydride (alias: bicycloheptenedicarboxylic anhydride, hereafter also referred to as "NAH") or Maleic anhydride, preferably NAH.

Examples of PAVE include: CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ , CF ₂ =CFOCF ₂ CF ₂ CF ₃ (PPVE), CF ₂ =CFOCF ₂ CF ₂ CF ₂ CF ₃ , CF ₂ =CFO( CF ₂ ) ₈ F, preferably PPVE. Examples of FAE include: CH ₂ =CH(CF ₂ ) ₂ F, CH ₂ =CH(CF ₂ ) ₃ F, CH ₂ =CH(CF ₂ ) ₄ F, CH ₂ =CF(CF ₂ ) ₃ H, CH ₂ =CF(CF ₂ ) _4H . In this case, it is preferable to contain 90 to 99 mol% of TFE units, 0.5 to 9.97 mol% of PAVE units, HFP units or FAE units, and 0.01 mol% of all the units contained in the F polymer. ~3 mol% of units with functional groups. In this case, the melting point of the F polymer is preferably 250 to 380°C, particularly preferably 280 to 350°C. Specific examples of the F polymer include polymers described in International Publication No. 2018/16644.

The polar solvent in the present invention is liquid at 25°C and may be protic or aprotic. In addition, the polar solvent may be an aqueous solvent or a non-aqueous solvent. One type of polar solvent may be used alone, or two or more types may be used in combination. The polar solvent is preferably water, amide, alcohol, sulfoxide, ester, ketone or glycol ether, more preferably water, ketone, ester or amide, particularly preferably ketone, ester or amide. Specific examples of polar solvents include water, methanol, ethanol, isopropyl alcohol, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrole. Methyl ketone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, dimethyl styrene, diethyl ether, dimethane, Ethyl lactate, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isopropyl ketone, cyclopentanone, cyclohexanone, ethylene glycol monoisopropyl ether, cellosolve (methyl cellosolve , ethyl cellosolve, etc.). The polar solvent is further preferably methyl ethyl ketone, cyclohexanone, γ-butyrolactone, 3-methoxy-N,N-dimethylpropylamide or N-methyl-2-pyrrolidone.

The AO polymer in the present invention contains a unit (hereinafter, also referred to as "unit F") based on a monomer having a fluoroalkyl group (monomer F) and a unit based on a monomer (monomer F) having an oxyalkylene glycol group. AO) unit (hereinafter, also referred to as "unit AO"). In addition, the AO polymer is a polymer other than the F polymer.

The so-called monomer F refers to having CH ₂ =CHO-, CH ₂ =CHCH ₂ O-, CH ₂ =CHC(O)O-, CH ₂ =CCH ₃ C(O)O-, CH ₂ =CCIC(O )O- and other polymerizable groups, and the general name of compounds with polyfluoroalkyl groups. An etheric oxygen atom may exist between the carbon atom-carbon atom bond of the polyfluoroalkyl group, or the carbon atom-carbon atom bond may form a double bond. The carbon number of the polyfluoroalkyl group is preferably 4 to 8. If the monomer F with a relatively short chain length of the fluorine-containing moiety is selected, not only will the dispersion have excellent dispersibility, but the physical properties such as wettability and adhesiveness of the F layer will be more easily improved.

Monomer F is preferably a compound represented by the following formula F. If the above-mentioned acrylate-based monomer F with a relatively short chain length of the fluorine-containing moiety is selected, not only the dispersibility of the dispersion liquid will be excellent, but also the physical properties such as wettability and adhesiveness of the F layer will be easily improved. Formula F: CH ₂ =CX ^F C(O)OQ ^F -R ^F The symbols in the formula represent the following meanings. X ^F is a hydrogen atom, a chlorine atom or a methyl group. Q ^F is an alkylene group having 1 to 4 carbon atoms, preferably methylene (-CH ₂ -) or ethylene (-CH ₂ CH ₂ -). ^RF is a polyfluoroalkyl group having 1 to 6 carbon atoms or a polyfluoroalkyl group having 3 to 6 carbon atoms containing etheric oxygen atoms. Examples of R ^F include -(CF ₂ ) ₄ F, -(CF ₂ ) ₆ F, -CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ or -CF(CF ₃ )OCF ₂ CF ₂ CF ₃ . Among them, from the viewpoint that the physical properties (wettability, adhesion, smoothness, etc.) of the F layer are more excellent, R ^F is preferably -(CF ₂ ) ₄ F or -(CF ₂ ) ₆ F, and more preferably -(CF ₂ ) ₆ F.

Specific examples of the monomer F include: CH ₂ =C(CH ₃ )C(O)OCH ₂ CH ₂ (CF ₂ ) ₆ F, CH ₂ =CHC(O)OCH ₂ CH ₂ (CF ₂ ) ₆ F, CH ₂ =C(CH ₃ )C(O)OCH ₂ CH ₂ (CF ₂ ) ₄ F, CH ₂ =CCIC(O)OCH ₂ CH ₂ (CF ₂ ) ₄ F.

The so-called monomer AO refers to polymerizable groups such as CH ₂ =CHO-, CH ₂ =CHCH ₂ O-, CH ₂ =CHC(O)O-, CH ₂ =CCH ₃ C(O)O-, and oxygen. The general name for compounds containing alkylene glycol residues. The monomer AO is preferably oxyalkylene glycol mono(meth)acrylate, and more preferably is a compound represented by the following formula H. If the above-mentioned acrylate-based monomer AO having a hydroxyl group and a polyoxyalkylene moiety is selected, not only will the dispersion have excellent dispersibility, but also the physical properties such as wettability and adhesion of the F layer (coating film) will be easily improved. .

Formula H: CH ₂ =CX ^H C(O)-(OZ ^H ) _m -OH The symbols in the formula represent the following meanings. X ^H is a hydrogen atom or methyl group. Z ^H is an alkylene group with 1 to 4 carbon atoms, preferably ethylene (-CH ₂ CH ₂ -), propylene (-CH ₂ CH (CH ₃ )-) or n-butyl (-CH ₂ CH ₂ CH ₂ CH ₂ -). Furthermore, Z ^H may contain one type of group or two or more types of groups. In the latter case, the arrangement of heterogeneous alkylene groups may be random or block-like. m is 3 to 200, preferably 6 to 100, more preferably 9 to 70, and particularly preferably 12 to 40 from the viewpoint of excellent wettability and smoothness of the F layer.

Specific examples of monomer AO include: CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₄ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₉ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₂₃ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₆₆ OH, CH ₂ =C( CH ₃ )C(O)(OCH ₂ CH ₂ ) ₉₀ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₁₂₀ OH, CH ₂ =CHC(O)(OCH ₂ CH ₂ ) ₄ OH, CH ₂ =CHC(O)(OCH ₂ CH ₂ ) ₈ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH(CH ₃ )) ₄ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH(CH ₃ )) ₈ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH(CH ₃ )) ₉ OH, CH ₂ =C(CH ₃ )C (O)(OCH ₂ CH(CH ₃ )) ₁₃ OH, CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₄ ·(OCH ₂ CH(CH ₃ )) ₃ OH, CH ₂ = C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₁₀ ·(OCH ₂ CH ₂ CH ₂ CH ₂ ) ₅ OH.

The fluorine content of AO polymer is 10 to 50% by mass. The lower limit is preferably 20 mass%, and the upper limit is preferably 40 mass%. If the lower limit of the fluorine content is within the above range, the dispersion liquid will have excellent dispersibility. If the upper limit of the fluorine content is within the above range, the affinity of the dispersant for each component of the dispersant is balanced, and not only the dispersibility of the dispersion but also its layer (coating film) formation properties are easily improved. For example, layer F has the characteristics of high wettability and excellent adhesion.

The hydroxyl value of AO polymer is 10~100 mgKOH/g. The lower limit is preferably 15 mgKOH/g. The upper limit is preferably 50 mgKOH/g, more preferably 35 mgKOH/g, and particularly preferably 30 mgKOH/g. If the lower limit of the hydroxyl value is within the above range, the dispersion liquid will have excellent dispersibility. If the upper limit of the hydroxyl value is within the above range, the affinity of the AO polymer for the F polymer and the affinity for the polar solvent are balanced, and not only the dispersibility of the dispersion but also its layer (coating film) formation properties are easily improved. . Specifically, the F layer can easily express the physical properties of the F polymer itself.

The oxyalkylene group content of the AO polymer (hereinafter also referred to as "AO content") is 5 to 75% by mass. The lower limit is preferably 20% by mass, more preferably 25% by mass. The upper limit is preferably 50% by mass, more preferably 45% by mass. If the lower limit of the AO content is within the above range, the dispersion liquid will have excellent dispersibility. If the upper limit of the AO content is within the above range, the affinity of the AO polymer for the F polymer and the affinity for the polar solvent are balanced, and not only the dispersibility of the dispersion but also its layer (coating film) formation properties are easily improved. . Specifically, the F layer can easily express the physical properties of the F polymer itself, and its smoothness can easily be improved.

Specific examples of preferred ranges of the fluorine content, oxyalkylene group content, and hydroxyl value of the AO polymer include those in which each value is in the order of 20 to 50 mass %, 20 to 50 mass %, and 15 to 35 mgKOH/g. Attitude. Furthermore, the sum of the fluorine content and the AO content of the AO polymer is less than 100% by mass, and is preferably 45 to 85% by mass. The fluorine content, hydroxyl value and AO content of AO polymer can be calculated based on the types and amounts of monomers used in the synthesis of AO polymer, or can be determined by analyzing the AO polymer.

The amount of unit F relative to all units contained in the AO polymer is preferably 60 to 90 mol%, particularly preferably 70 to 90 mol%. The amount of AO units relative to all units contained in the AO polymer is preferably 10 to 40 mol%, particularly preferably 10 to 30 mol%. The AO polymer may contain only unit F and unit AO, or may contain additional units other than unit F and unit AO within a range that does not impair the effects of the present invention. The total amount of unit F and unit AO relative to all units contained in the AO polymer is preferably 90 to 100 mol%, particularly preferably 99 to 100 mol%. That is, the AO polymer is preferably a polymer containing substantially only the unit F and the unit AO. The AO polymer is preferably nonionic. The mass average molecular weight of the AO polymer is preferably 2,000 to 80,000, particularly preferably 6,000 to 20,000.

Preferred specific examples of the AO polymer include polymers containing units based on the compound represented by the following formula F1 and units based on the compound represented by the following formula H1, and having a fluorine content, an oxyalkylene group content, and a hydroxyl group. The values are 20 to 40 mass%, 25 to 45 mass%, and 15 to 30 mgKOH/g in order. Formula F1: CH ₂ =CX ^F1 C(O)O-CH ₂ CH ₂ -R ^F1 Formula H1: CH ₂ =CX ^H1 C(O)-(OCH ₂ CH ₂ ) _m1 ^-OH base. R ^F1 is -(CF ₂ ) ₄ F or -(CF ₂ ) ₆ F. X ^H1 is a hydrogen atom or methyl group. m1 is 9-70, preferably 12-40.

The amount of units based on the compound represented by formula F1 is 60 to 90 mol%, preferably 70 to 90 mol%, relative to all the units contained in the AO polymer. The amount of units based on the compound represented by formula H1 relative to all units contained in the above-mentioned AO polymer is 10 to 40 mol%, preferably 10 to 30 mol%. The total amount of units based on the compound represented by formula F1 and the compound represented by formula H1 is 90 to 100 mol%, preferably 100 mol%, based on all the units contained in the AO polymer. AO polymers may also have hydroxyl or carboxyl groups at the end of the main chain. In this case, the leveling properties of the dispersion of the present invention can be easily improved. The above-mentioned AO polymer is obtained by adjusting the type of polymerization initiator or chain transfer agent used in its production, for example.

The ratio of the F polymer in the dispersion of the present invention is preferably 5 to 60 mass %, particularly preferably 30 to 50 mass %. Within this range, it is easy to form an F layer with excellent electrical properties and mechanical strength. The ratio of the dispersant in the dispersion of the present invention is preferably 1 to 30 mass%, particularly preferably 3 to 15 mass%. Within this range, the dispersibility is further improved, and the physical properties (wettability, adhesiveness, etc.) of the F layer are more easily improved. The ratio of the content of the AO polymer to the content of the F polymer in the dispersion of the present invention is preferably 0.25 or less, more preferably 0.2 or less, and particularly preferably 0.1 or less. The lower limit of the above ratio is preferably 0.01.

Since the AO polymer has high affinity with both the F polymer and the polar solvent, the dispersion has excellent dispersion stability even when the above ratio is small (when the content of the AO polymer is small). Furthermore, if the above-mentioned ratio is within the above-mentioned range, it is easy to form the F layer which has higher wettability, more excellent adhesion, and directly expresses the physical properties of the F polymer itself. The ratio of the polar solvent in the dispersion of the present invention is preferably 15 to 65% by mass, particularly preferably 25 to 50% by mass. Within this range, the coating properties of the dispersion liquid are excellent, and the layer (coating film) formation properties are easily improved.

The dispersion of the present invention may also contain other materials within the scope that does not impair the effects of the present invention. Other materials may or may not be soluble in the dispersion. The above-mentioned other materials may be organic substances or inorganic substances. The organic substance may be a non-hardening resin or a hardening resin. Examples of the non-hardening resin include heat-melting resin and non-melting resin. Examples of the hot meltable resin include thermoplastic polyimide and the like. Examples of the non-melting resin include cured products of curable resins. In addition, the shape of other materials may be granular or fibrous.

Examples of the curable resin include polymers having reactive groups, oligomers having reactive groups, low molecular compounds, low molecular compounds having reactive groups, and the like. Examples of reactive groups include carbonyl group-containing groups, hydroxyl groups, amine groups, epoxy groups, and the like. Examples of curable resins include: epoxy resin, thermosetting polyimide, polyamide acid, acrylic resin, phenol resin, polyester resin, polyolefin resin, modified polyphenylene ether resin, and polyfunctional cyanic acid. Ester resin, multifunctional maleimide-cyanate ester resin, multifunctional maleimide resin, vinyl ester resin, urea resin, diallyl phthalate resin, melamine resin, Guanamine resin, melamine-urea co-condensation resin.

Examples of epoxy resins include naphthalene type, cresol novolak type, bisphenol A type, bisphenol F type, bisphenol S type, alicyclic type, aliphatic chain type, and cresol novolak type. , phenol novolak type, alkyl novolac type, aralkyl type, biphenol type and other epoxy resins. Examples of the bismaleimide resin include the resin composition (BT resin) described in Japanese Patent Application Laid-Open No. 7-70315 and the resin described in International Publication No. 2013/008667. Examples of the diamine and polycarboxylic dianhydride that form the polyamide acid include Japanese Patent No. 5766125 [0020], Japanese Patent No. 5766125 [0019], and Japanese Patent Laid-Open No. 2012-145676. The compounds described in [0055], [0057], etc.

Examples of the hot-meltable resin include: thermoplastic polyimide, polyester resin, polyolefin resin, styrene resin, polycarbonate, thermoplastic polyimide, polyarylate, polyethylene, polyarylene, and aromatic resin. Polyamide, aromatic polyether amide, polyphenylene sulfide, polyaryl ether ketone, polyamide imide, liquid crystalline polyester, polyphenylene ether, and hardened resins with hot melt properties are preferred. It is thermoplastic polyimide, liquid crystalline polyester or polyphenylene ether. Examples of the above-mentioned other materials include thixotropy imparting agents, defoaming agents, fillers, reactive alkoxysilane, dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, and anti-oxidants. Electrostatic agents, whitening agents, colorants, conductive agents, release agents, surface treatment agents, viscosity regulators, flame retardants, etc.

Preferable specific examples of other materials include fillers with smaller relative dielectric constants and smaller dielectric loss tangents. If the dispersion liquid of the present invention contains the above-mentioned filler, the electrical characteristics of the laminate or printed circuit board described below can be more easily improved. In this case, examples of fillers or compounds forming fillers include: silica, clay, talc, calcium carbonate, mica, diatomaceous earth, aluminum oxide, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, and iron oxide. , cerium oxide, tin oxide, antimony oxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, alkaline magnesium carbonate, non-alkaline magnesium carbonate, zinc carbonate, barium carbonate, dawsonite, aluminum magnesium carbonate, calcium sulfate , barium sulfate, calcium silicate, boron nitride, aluminum nitride, montmorillonite, silicate, talc, cordierite, bentonite, activated clay, sepiolite, filamentous aluminite, sericite, glass Fiber, short glass fiber, glass beads, silica-based hollow spheres, carbon black, carbon nanotubes, carbon nanohorns, graphite, carbon fiber, glass hollow spheres, carbon hollow spheres, wood powder, zinc borate, polyethylene Amine powder and filler may be used individually by 1 type, and may be used in combination of 2 or more types.

Preferable specific examples of other materials include magnesium oxide, silicate, boron nitride, and aluminum nitride, which are fillers having a particularly low dielectric loss tangent. When the dispersion of the present invention contains the above-mentioned filler, its content is preferably such that the linear expansion coefficient of the F layer formed from the dispersion, especially the annealed F layer, becomes 10 to 100 ppm/°C. Decide. Specifically, the above content can be determined according to the type and shape of the filler. If it is a filler with an aspect ratio of 2 or more, it is preferably 1 to 50 mass%, more preferably 10 to 50 mass%. If it is a filler with an aspect ratio of The spherical filler of 1 to 2 is preferably 1 to 80 mass%, more preferably 10 to 80 mass%. Specific examples of the former filler include fibrous magnesium sulfate (manufactured by UBE MATERIALS Co., Ltd., trade name "MOS-HIGE", etc.), glass cut fibers (manufactured by Nittobo Co., Ltd., trade name "PF") ”, “SS”, etc.). The F layer formed from a dispersion containing these fillers has improved absorption of light with wavelengths in the ultraviolet region, especially light with wavelengths of 266 nm and 355 nm, so UV- YAG laser processability is improved. Therefore, a high-precision printed circuit board can be more easily manufactured from the laminate described below.

From the viewpoint of maintaining or improving the bendability of the F layer, when the dispersion of the present invention contains a filler, its shape is preferably granular, and more preferably granular with a particle diameter of 1 μm or less. Moreover, a filler with an aspect ratio of 2 or more and a filler with an aspect ratio of 1 to 2 may be used together. The filler can also be surface treated using a silane coupling agent, etc. The water absorption rate of the filler is preferably 3% or less, more preferably 1% or less.

The viscosity of the dispersion of the present invention is preferably 10000 mPa·s or less, more preferably 50 to 10000 mPa·s, further preferably 75 to 1000 mPa·s, particularly preferably 100 to 500 mPa·s. In this case, not only the dispersibility of the dispersion liquid is excellent, but also its coating properties and compatibility with varnishes of different resin materials are also excellent. The thixotropy ratio (eta ₁ /eta ₂ ) of the dispersion of the present invention is preferably 1.0 to 2.2, more preferably 1.4 to 2.2, and particularly preferably 1.5 to 2.0. In this case, not only the dispersibility of the dispersion liquid is excellent, but also the homogeneity of the F layer can be easily improved. Furthermore, the thixotropy ratio (η ₁ /η ₂ ) is the viscosity η ₁ of the dispersion measured at a rotation speed of 30 rpm divided by the viscosity η of the dispersion measured at a rotation speed of 60 rpm. ₂ and calculated.

As described above, the dispersion liquid of the present invention can form the F layer with excellent adhesiveness. Preferably, the dispersion of the present invention is used to form layer F on the surface of the substrate. The F layer may be a single layer or a laminate containing a plurality of layers. Moreover, each F layer may also contain other materials mentioned above (various organic resins, fillers, etc.). For example, the dispersion of the present invention containing no other materials or a small content of other materials can be used to form the first F layer on the surface of the substrate, and then a dispersion of the present invention with a relatively high content of other materials can be used to form the first F layer on the surface of the substrate. A second F layer is formed on the surface of the first F layer. According to the above method, it is easy to obtain a laminated body that has excellent adhesion to the base material and has better physical properties due to other materials. When forming the F layer, it is preferred to heat the solvent to distill away the solvent from the dispersion of the present invention, thereby forming the F layer. The substrate is preferably metal foil. Examples of the material of the metal foil include: copper, copper alloy, stainless steel, nickel, nickel alloy (also including 42 alloy), aluminum, aluminum alloy, titanium, titanium alloy, etc. Examples of the metal foil include rolled copper foil, electrolytic copper foil, and the like. The surface of the metal foil can be subjected to anti-rust treatment (oxide film such as chromate, etc.) or roughened.

The ten-point average roughness of the surface of the metal foil is preferably 0.2 to 1.5 μm. In this case, the adhesion to the F layer is likely to be good. The thickness of the metal foil is sufficient as long as it can function in the application of the metal foil with resin. The thickness of the metal foil is the thickness above the ten-point average roughness of the surface, preferably 2 to 40 μm. The entire surface of the metal foil may be treated with a silane coupling agent, or only a part thereof may be treated with a silane coupling agent.

Furthermore, as the metal foil, a laminated metal foil (metal foil with a carrier) in which an ultra-thin metal foil and a carrier metal foil are laminated can also be used. The thickness of the ultra-thin metal foil is preferably 2 to 5 μm. For example, if the F layer is formed from the dispersion liquid of the present invention on the ultra-thin copper foil side of the copper foil with a carrier, and then only the carrier copper foil is peeled off, a laminate having the ultra-thin copper foil and the F layer in sequence can be easily produced. body. If the above-mentioned laminated body is subjected to the MSAP (Modified Semi-Additive Process) method, an extremely thin copper foil layer can also be used as a plating seed layer to form fine patterns. It is preferable that a peeling layer is formed between the metal foils of the metal foil with a carrier. From the viewpoint of heat resistance, the peeling layer is preferably a metal layer containing nickel or chromium, or a multilayer metal layer obtained by multilayering the above metal layers. If it is the said peeling layer, even after the process of providing at 300 degreeC or more, the carrier copper foil can be easily peeled off from the ultra-thin copper foil. As a specific example of the metal foil with a carrier, there is a trade name "FUTF-5DAF-2" manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.

The dispersion liquid of the present invention can be applied (supplied) to the surface of a metal foil, and the metal foil can be heated to produce a resin-coated metal foil having an F layer. The resin-attached metal foil in the present invention has an F layer on at least one surface of the metal foil. That is, the metal foil with resin may have the F layer only on one side of the metal foil, or may have the F layer on both sides of the metal foil. The warpage rate of the resin-coated metal foil is preferably 25% or less, particularly preferably 7% or less. In this case, when the metal foil with resin is processed into a printed circuit board, the processing properties and the transmission characteristics of the obtained printed circuit board are excellent. The dimensional change rate of the resin-coated metal foil is preferably ±1% or less, particularly preferably ±0.2% or less. In this case, it is easy to process the metal foil with resin into a printed circuit board, and it is easy to make it multi-layered.

The water contact angle on the surface of the F layer is preferably 70 to 100°, particularly preferably 70 to 90°. In this case, the adhesion between the F layer and other base materials is even better. If it is more than the lower limit of the above range, the electrical characteristics when processing the resin-coated metal foil into a printed circuit board will be further excellent. The thickness of the F layer is preferably 1 to 200 μm, more preferably 1 to 50 μm, further preferably 1 to 15 μm, particularly preferably 1 to 9 μm. Within this range, it is easy to balance the electrical characteristics when processing the resin-coated metal foil into a printed circuit board and the suppression of warpage of the resin-coated metal foil. When the metal foil with resin has F layers on both sides of the metal foil, from the viewpoint of suppressing warpage of the metal foil with resin, the composition and thickness of the two F layers are preferably the same. The relative dielectric constant of the F layer is preferably 2.0-3.5, more preferably 2.0-3.0. In this case, the resin-coated metal foil can be favorably used for printed circuit boards and the like that require a low dielectric constant.

The coating method is sufficient as long as it forms a stable wet film containing the dispersion on the surface of the coated metal foil. Examples include: spray method, roller coating method, spin coating method, gravure coating method, and microgravure coating. Distribution method, gravure offset printing method, knife coating method, contact coating method, rod coating method, die coating method, fountain Mayer bar method (fountain Mayer bar method), slit die coating method wait. After applying the dispersion liquid, when heating the metal foil, it is preferable to maintain the temperature in a low-temperature region so that the solvent is distilled off. The temperature in the low-temperature region is preferably 80°C or higher and less than 180°C, and particularly preferably 120°C to 170°C. Maintaining the temperature in the low-temperature region can be implemented in one stage, or it can be divided into two or more stages and implemented at different temperatures. Examples of methods for maintaining the temperature in low-temperature areas include using an oven, using a ventilation drying oven, and irradiating heat waves such as infrared rays.

The atmosphere when maintaining the temperature of the low-temperature area can be either under normal pressure or under reduced pressure. In addition, the above-mentioned atmosphere may be any one of an oxidizing gas atmosphere, a reducing gas atmosphere, and an inert gas atmosphere. Examples of the inert gas include helium, neon, argon, and nitrogen, and nitrogen is preferred. Examples of the reducing gas include hydrogen gas. Examples of the oxidizing gas include oxygen.

From the viewpoint of promoting the oxidative decomposition of the dispersant and further improving the adhesion of the F layer, the atmosphere when maintaining the temperature in the low-temperature region is preferably an atmosphere containing oxygen. The oxygen concentration (volume basis) in the atmosphere containing oxygen is preferably 1×10 ² to 3×10 ⁵ ppm, particularly preferably 0.5×10 ³ to 1×10 ⁴ ppm. Within this range, it is easy to maintain a balance between the oxidative decomposition of the dispersant and the inhibition of oxidation of the metal foil. The time to maintain the temperature of the low temperature area is preferably 0.1 to 10 minutes, particularly preferably 0.5 to 5 minutes.

In the manufacturing method of the resin-coated metal foil of the present invention, it is preferable to further bake the F polymer in a temperature region exceeding the holding temperature in the low-temperature region (hereinafter also referred to as "baking region"), and An F layer is formed on the surface of the metal foil. The temperature of the roasting area indicates the temperature of the atmosphere during roasting. It is considered that the F layer in the present invention is formed by densely accumulating powder particles and fusing the F polymer. Furthermore, if the dispersion liquid contains a thermofusible resin, an F layer containing a mixture of the F polymer and a molten resin will be formed. If the dispersion liquid contains a thermosetting resin, a hardened layer containing the F polymer and the thermosetting resin will be formed. The F layer of things.

Examples of roasting methods include using an oven, using a ventilated drying furnace, and irradiating heat waves such as infrared rays. In order to improve the smoothness of the surface of the F layer, a heating plate, a heating roller, etc. may be used for pressurization. As a method of heating, the method of irradiating far-infrared rays is preferable from the viewpoint that baking can be performed in a short time and the far-infrared furnace is relatively small. The heating method can also combine infrared heating and hot air heating. From the perspective of promoting homogeneous fusion of F polymer, the effective wavelength band of far infrared rays is preferably 2 to 20 μm, and more preferably 3 to 7 μm.

The atmosphere during roasting can be either under normal pressure or under reduced pressure. In addition, the atmosphere during the above-mentioned baking may be any one of an oxidizing gas atmosphere, a reducing gas atmosphere, and an inert gas atmosphere. From the viewpoint of suppressing oxidative degradation of the metal foil and the formed F layer, reducing gas atmosphere is preferred. non-toxic gas atmosphere or inert gas atmosphere. Examples of the inert gas include helium, neon, argon, and nitrogen, and nitrogen is preferred. Examples of the reducing gas include hydrogen gas. Examples of the oxidizing gas include oxygen.

The atmosphere during baking is preferably a gas atmosphere composed of an inert gas with a low oxygen concentration, and more preferably a gas atmosphere composed of nitrogen with an oxygen concentration (volume basis) of less than 500 ppm. The optimal oxygen concentration (volume basis) is 300 ppm or less. In addition, the oxygen concentration (volume basis) is usually 1 ppm or more. Within this range, the oxidative decomposition of the dispersant is further inhibited and the hydrophilicity of the F layer is easily improved. The temperature of the roasting zone is preferably 250°C to 400°C or less, particularly preferably 300°C to 380°C. The time to maintain the temperature of the roasting area is preferably 30 seconds to 5 minutes, particularly preferably 1 to 2 minutes.

In order to suppress the linear expansion of the F layer, or further improve the adhesion of the F layer, the surface of the F layer can also be surface treated in the resin-attached metal foil of the present invention. Examples of surface treatment methods for the surface of the F layer include: annealing treatment, corona discharge treatment, atmospheric pressure plasma treatment, vacuum plasma treatment, UV ozone treatment, excimer treatment, chemical etching, silane coupling treatment, micro-roughening Face processing, etc. The temperature in the annealing treatment is preferably 120 to 180°C. The pressure during annealing treatment is preferably 0.005 to 0.015 MPa. The preferred annealing treatment time is 30 to 120 minutes.

Examples of plasma irradiation devices used in plasma treatment include: high-frequency induction method, capacitive coupling electrode method, corona discharge electrode-plasma jet method, parallel plate type, remote plasma type, atmospheric pressure plasma type, ICP (Inductive Coupled Plasma, inductively coupled plasma) type high-density plasma type, etc. Examples of gases used in plasma processing include oxygen, nitrogen, rare gases (argon, etc.), hydrogen, ammonia, etc., with rare gases or nitrogen being preferred. Specific examples of gases used in plasma processing include: argon gas; a mixed gas of hydrogen and nitrogen; and a mixed gas of hydrogen, nitrogen and argon.

Since the surface of the F layer of the resin-coated metal foil obtained in the present invention has excellent adhesion, it can be easily and firmly laminated with other substrates. Examples of other substrates include a heat-resistant resin film, a prepreg that is a precursor of a fiber-reinforced resin board, a laminated body having a heat-resistant resin film layer, a laminated body having a prepreg layer, and the like. The prepreg system is a sheet-like substrate made by impregnating a base material (tow, woven fabric, etc.) of reinforced fibers (glass fiber, carbon fiber, etc.) with thermosetting resin or thermoplastic resin. The heat-resistant resin film is a film containing one or more types of heat-resistant resin, and may be a single-layer film or a multi-layer film. Examples of the heat-resistant resin include polyimide, polyarylate, polyester, polyarylene, aromatic polyamide, aromatic polyetheramide, polyphenylene sulfide, polyaryl ether ketone, and polyamide. Imide, liquid crystalline polyester, etc.

As a method of laminating another base material on the surface of the F layer of the resin-attached metal foil in the present invention, there is a method of hot-pressing the resin-attached metal foil and other substrates. In other cases where the substrate is a prepreg, the pressing temperature is preferably below the melting point of the F polymer, more preferably 120 to 300°C. When the other substrate is a heat-resistant resin film, the pressing temperature is preferably 310 to 400°C. From the viewpoint of suppressing the incorporation of bubbles and suppressing deterioration due to oxidation, hot pressing is particularly preferably performed at a vacuum degree of 20 kPa or less. Moreover, when hot pressing is performed, it is preferable to raise the temperature after reaching the above vacuum degree. If the temperature is raised before reaching the above vacuum level, the F layer will be pressed in a softened state, that is, a state with a certain degree of fluidity and adhesion, resulting in the generation of bubbles. From the viewpoint of suppressing damage to the substrate and ensuring firm contact between the F layer and the substrate, the pressure during hot pressing is preferably 0.2 to 10 MPa.

The resin-coated metal foil or its laminate in the present invention can be used as a flexible copper-clad laminated board or a rigid copper-clad laminated board to produce a printed circuit board. For example, if a method of processing the metal foil with resin of the present invention into a conductor circuit (pattern circuit) of a specific pattern by etching or the like is used, or if a method of using the metal foil with resin of the present invention is used, By processing pattern circuits by electrolytic plating (semi-additive method (SAP method), modified semi-additive method (MSAP method), etc.), a printed circuit board can be produced from the metal foil with resin in the present invention. In the manufacture of printed circuit boards, after forming a pattern circuit, an interlayer insulating film can be formed on the pattern circuit, and then a conductor circuit can be formed on the interlayer insulating film. The interlayer insulating film can also be formed from the dispersion of the present invention. In the manufacture of printed circuit boards, a solder resist layer can also be laminated on the pattern circuit. The solder resist layer can also be formed from the dispersion of the present invention. In the production of printed circuit boards, a cover film can also be laminated on the pattern circuit.

The dispersion liquid of the present invention has been described above. However, the present invention is not limited to the configuration of the above embodiment. For example, the dispersion liquid of the present invention may be added with any other arbitrary structure to the structure of the above-mentioned embodiment, or may be replaced with any other structure that performs the same function. Example

Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited thereto. Various measurement methods and materials used are shown below. ＜Powder D50 and D90＞ The powder was dispersed in water and measured using a laser diffraction/scattering particle size distribution measuring device (LA-920 measuring device manufactured by Horiba Manufacturing Co., Ltd.). ＜Dispersion stability of dispersion＞ The dispersion state of the dispersion liquid after standing for one week was visually confirmed and evaluated based on the following criteria. ○: Although it precipitated, it redispersed if gently stirred. △: Redispersion occurs when shearing and stirring are performed. ×: No further dispersion occurs even if shearing is applied.

＜Water contact angle of F layer＞ Pure water (approximately 2 μL) was placed on the surface of the F layer of the metal foil with resin at 25°C, and a contact angle meter (CA-X model manufactured by Kyowa Interface Science Co., Ltd.) was used to measure the relationship between the water droplets and the F layer. The angle formed by the surface is evaluated based on the following criteria. ○: The water contact angle is 80° or less. ×: Water contact angle exceeds 80°. ＜Flatness of layer F＞ The unevenness of the F layer surface was observed using an optical interference microscope, and the unevenness of the central portion and end portions (5 locations) was evaluated based on the following criteria. ○: The unevenness width (average value) of the end portion relative to the central portion is 10% or less. ×: The unevenness (average) of the end portion relative to the center portion exceeds 10%. ＜Peel strength of laminate＞ A laminated body cut into a rectangular shape (length 100 mm, width 10 mm) is fixed at a position 50 mm from one end in the length direction, and a stretching speed of 50 mm/min is used from one end in the length direction relative to the laminated body. The maximum load applied when peeling the metal foil from the F layer at 90° is defined as the peel strength (N/cm).

[F polymer] F Polymer 1: A copolymer containing 97.9 mol% of TFE units, 0.1 mol% of NAH units, and 2.0 mol% of PPVE units. [powder] Powder 1: Powder containing polymer 1 with D50 of 1.7 μm and D90 of 3.8 μm.

[Dispersant] Dispersant 1: Polymer containing 81 mol% of monomer F ¹ unit and 19 mol% of monomer AO ² unit (fluorine content: 35 mass%, hydroxyl value: 19 mgKOH/g, AO content :34% by mass). Dispersant 2: Polymer containing 68 mol% of monomer F ¹ unit and 32 mol% of monomer AO ³ unit (fluorine content: 13 mass%, hydroxyl value: 14 mgKOH/g, AO content: 74 mass% ). Dispersant 3: Polymer containing 56 mol% of monomer F ¹ unit and 44 mol% of monomer AO ² unit (fluorine content: 19 mass%, hydroxyl value: 33 mgKOH/g, AO content: 60 mass% ). Dispersant 4: Polymer containing 42 mol% of monomer F ¹ unit and 58 mol% of monomer AO ² unit (fluorine content: 12 mass%, hydroxyl value: 39 mgKOH/g, AO content: 70 mass% ). Dispersant 5: Copolymer of ² units of monomer F and ¹ unit of monomer AO (fluorine content: 35 mass%, hydroxyl value: 47 mgKOH/g, AO content: 38 mass%). Furthermore, the AO content in each dispersant is the amount of (OCH ₂ CH ₂ ) units contained in the monomer AO used.

Monomer F ¹ : CH ₂ =C(CH ₃ )C(O)OCH ₂ CH ₂ (CF ₂ ) ₆ F. Monomer F ² : CH ₂ =C(CH ₃ )C(O)OCH ₂ CH ₂ CH ₂ CH ₂ OCF(CF ₃ )(C(=C(CF ₃ ) ₂ ) (CF(CF ₃ ) ₂ )) . Monomer AO ¹ : CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₉ OH. Monomer AO ² : CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₂₃ OH. Monomer AO ³ : CH ₂ =C(CH ₃ )C(O)(OCH ₂ CH ₂ ) ₆₆ OH. Furthermore, the number of (OCH ₂ CH ₂ ) units in monomer AO is an average value.

[metal foil] Copper foil 1: Copper foil with a roughened layer (thickness 12 μm, average ten-point roughness of the surface 0.6 μm). [other materials] Filler 1: Silica particles (manufactured by Tosoh Corporation, NIPSIL (registered trademark) VN3) Filler 2: Magnesium oxide (manufactured by Tateho Chemical Company, DISPERMAG TN-1) Filler 3: Glass cut fiber (manufactured by Nittobo Co., Ltd., PF)

[Example 1] Production example of dispersion liquid Mix 40 parts by mass of N-methyl-2-pyrrolidone and 12 parts by mass of dispersant 1, and then mix 48 parts by mass of powder 1 to obtain a ratio of the content of the dispersant to the content of the F polymer: 0.25 dispersion. Dispersants 2, 3, and 4 were used instead of dispersant 1 to obtain dispersions. In each dispersion liquid, Powder 1 was uniformly dispersed. [Example 2] Production example and evaluation example of dispersion liquid Mix 64 parts by mass of N-methyl-2-pyrrolidone and 3 parts by mass of dispersant 1, and then mix 33 parts by mass of powder 1 to prepare a ratio of the content of the dispersant to the content of the F polymer: 0.1 dispersion 1. Dispersants 2, 3, 4, and 5 were produced in the same manner except that dispersants 2, 3, 4, and 5 were used instead of dispersant 1, and the dispersion stability of the dispersions was evaluated. The results are summarized in Table 1.

[Table 1] Dispersions dispersant Dispersion Kind Fluorine content [mass %] AO content [mass %] Hydroxyl value [mgKOH/g] 1 Dispersant 1 35 34 19 ○ 2 Dispersant 2 13 74 14 △ 3 Dispersant 3 19 60 33 △ 4 Dispersant 4 12 70 39 × 5 Dispersant 5 35 38 47 △

Furthermore, methyl ethyl ketone 3-methoxy-N,N-dimethylpropylamide or cyclohexanone was used instead of N-methyl-2-pyrrolidone in dispersion 1, except that A dispersion liquid was prepared in the same manner, and the prepared dispersion liquid showed the same dispersion properties as the dispersion liquid 1.

[Example 3] Production example and evaluation example of metal foil with resin Use a die nozzle coater to apply dispersion 1 on the surface of copper foil 1, pass it through a ventilated drying furnace (atmosphere temperature: 120°C) for 1 minute, and then pass it through a far-infrared furnace (temperature: 340°C) for 3 minutes. A resin-attached copper foil 1 having an F layer (thickness 5 μm) of the polymer 1 on the surface of the copper foil 1 was obtained. Furthermore, the resin-attached copper foil 5 was manufactured in the same manner except that the dispersion liquid 5 was used instead of the dispersion liquid 1 . The water contact angle and flatness of the F layer in each resin-attached copper foil were evaluated. The results are summarized in Table 2.

[Table 2] Copper foil with resin Dispersions dispersant Evaluation of Level F Kind Fluorine content [mass %] AO content [mass %] Hydroxyl value [mgKOH/g] water contact angle Flatness 1 1 Dispersant 1 35 34 19 ○ ○ 5 5 Dispersant 5 35 38 47 × ×

[Example 4] Evaluation example of metal foil with resin The surface of the F layer of the copper foil with resin 1 was subjected to vacuum plasma treatment. In addition, the processing conditions were set to output: 4.5 kW, introduction gas: argon, introduction gas flow rate: 50 cm ³ /min, pressure: 50 mTorr (6.7 Pa), and processing time: 2 minutes. On the surface of the F layer of the treated resin-attached copper foil 1, FR-4 (manufactured by Hitachi Chemical Co., Ltd., GEA-67N 0.2t (HAN), reinforcing fiber: glass fiber, matrix resin) was superposed as a prepreg: Epoxy resin, thickness: 0.2 mm), and vacuum hot pressing was performed to obtain a laminate 1. In addition, the processing conditions are as follows: temperature: 185°C, pressurizing pressure: 3.0 MPa, pressurizing time: 60 minutes. The peel strength of the obtained laminated body 1 was 8 N/cm.

[Example 5] Production evaluation example of resin-coated metal foil After 45 parts by mass of NMP, a solution (5 parts by mass) containing 2.5 parts by mass of dispersant 1, and 50 parts by mass of powder 1 were put into the crucible, zirconia balls were put into the crucible. Thereafter, the crucible was rotated at 150 rpm for 1 hour to prepare powder dispersion 4A. Furthermore, 10 parts by mass of filler 1 was put into the crucible, and the crucible was rotated for 1 hour to prepare powder dispersion 4B. The powder dispersion 4B is applied to the copper foil 1 in a roll-to-roll manner using a reverse contact method to form a liquid coating. Copper foil 1 is coated with an acrylic adhesive film laminated on copper foil 1 as a support film. Then, the liquid coating was passed through a drying oven at 120° C. for 5 minutes, heated and dried to obtain a dry coating. Thereafter, the dried coating was heated at 380° C. for 3 minutes in a nitrogen oven. Thereby, the copper foil with resin 4 in which the F layer having a thickness of 3 μm was formed on the surface of the copper foil 1 was obtained. The copper foil 4 with resin has high light absorption at wavelengths of 266 nm and 355 nm and has excellent UV laser processability. The warpage caused by the difference in linear expansion coefficient between the copper foil and the F layer is also reduced. Using the resin-coated copper foil 4, a laminated body 4 was obtained in the same manner as in Example 4, and a transmission line was formed on the copper foil of the laminated body 4 to obtain a printed circuit board 4. The relative dielectric constant and dielectric loss tangent of the printed circuit board 4 are low, and the transmission characteristics of high-frequency signals are excellent.

[Example 6] Production evaluation example of resin-coated metal foil 100 parts by mass of the powder dispersion 4A and 20 parts by mass of the filler 2 were put into a crucible, and the crucible was rotated for 1 hour to prepare a powder dispersion 5B. The powder dispersion 5B is applied to the copper foil 1 using a die coating method to form a liquid coating. Then, the liquid coating was passed through a drying oven at 120° C. for 5 minutes, heated and dried to obtain a dry coating. Thereafter, the dried coating was heated at 380° C. for 10 minutes in a far-infrared furnace under a nitrogen atmosphere. Thereby, the copper foil with resin 5 in which the F layer having a thickness of 100 μm was formed on the surface of the copper foil 1 was obtained. The resin-coated copper foil 5 has excellent dielectric properties, and its warpage is also reduced. Using the resin-coated copper foil 5, a laminated body 5 was formed in the same manner as in Example 4, and a transmission line was formed on the copper foil of the laminated body 5 to obtain a printed circuit board 5. The relative dielectric constant and dielectric loss tangent of the printed circuit board 5 are low, and the transmission characteristics of high-frequency signals are excellent.

[Example 7] Production evaluation example of resin-coated metal foil 100 parts by mass of the powder dispersion 4A and 10 parts by mass of the filler 3 were put into a crucible, and the crucible was rotated for 1 hour to prepare a powder dispersion 6B. The powder dispersion 6B is applied to the copper foil 1 using a die nozzle coating method to form a liquid coating. Then, the liquid coating was passed through a drying oven at 120° C. for 5 minutes, heated and dried to obtain a dry coating. Thereafter, the dried coating was heated at 380° C. for 10 minutes under far infrared rays in a nitrogen atmosphere. Thereby, the copper foil with resin 6 in which the F layer having a thickness of 100 μm was formed on the surface of the copper foil 1 was obtained. The warpage of the resin-coated copper foil 6 is reduced, cracks are less likely to occur even if it is bent, and the softness is maintained. Using the copper foil 6 with resin, a laminated body 6 was formed in the same manner as in Example 4, and a transmission line was formed on the copper foil of the laminated body 6 to obtain a printed circuit board 6 . The relative dielectric constant and dielectric loss tangent of the printed circuit board 6 are low, and the transmission characteristics of high-frequency signals are excellent. industrial availability

The dispersion of the present invention has excellent dispersibility and layer (coating film) formation properties, and can be easily processed into films, fiber-reinforced films, prepregs, and metal laminates (metal foil with resin). The resulting processed articles It can be used as materials for antenna parts, printed circuit boards, aircraft parts, automobile parts, sports equipment, food industry products, saws, sliding bearings, etc.

Claims (12)

A dispersion liquid containing a powder containing a tetrafluoroethylene polymer, a polar solvent and a dispersing agent, wherein the powder is dispersed in the polar solvent, and the dispersing agent is an oxyalkylene polymer based on: The unit of the compound represented by formula F and the unit based on the monomer having an oxyalkylene glycol group have a fluorine content of 20 to 40 mass %, an oxyalkylene group content of 5 to 75 mass %, and a hydroxyl value of 15 to 30mgKOH/g, formula F: CH ₂ =CX ^F C(O)OQ ^F -R ^F (where X ^F represents a hydrogen atom, a chlorine atom or a methyl group, Q ^F represents an alkylene group with 1 to 4 carbon atoms, R ^F means -(CF ₂ ) ₄ F or -(CF ₂ ) ₆ F). The dispersion of claim 1, wherein the above-mentioned monosystem having an oxyalkylene glycol group is a compound represented by the following formula H: Formula H: CH ₂ =CX ^H C(O)-(OZ ^H ) _m -OH (In the formula, X ^H represents a hydrogen atom or a methyl group, Z ^H represents an alkylene group with 1 to 4 carbon atoms, and m is 3 to 200). The dispersion of claim 1 or 2, wherein the compound represented by the above formula F is a compound represented by the following formula F1, and the above-mentioned monosystem having an oxyalkylene glycol group is a compound represented by the following formula H1: Formula F1 : CH ₂ =CX ^F1 C(O)O-CH ₂ CH ₂ -R ^F1 Formula H1: CH ₂ =CX ^H1 C(O)-(OCH ₂ CH ₂ ) _m1 -OH (where X ^F1 represents a hydrogen atom Or methyl group, R ^F1 represents -(CF ₂ ) ₄ F or -(CF ₂ ) ₆ F, X ^H1 represents hydrogen atom or methyl group, m1 is 9~70). The dispersion of claim 1 or 2, wherein the oxygen alkylene group content of the above polymer is 20 to 50% by mass. The dispersion of claim 1 or 2, wherein the above-mentioned polymer contains 60 to 90 mol% of the above-mentioned units based on the compound represented by formula F relative to all the units contained in the polymer. The dispersion of claim 1 or 2, wherein the above-mentioned polymer contains 10 to 40 mol% of the above-mentioned units based on the monomer having an oxyalkylene glycol group relative to all the units contained in the polymer. The dispersion of claim 1 or 2, wherein the above-mentioned polymer contains a total of 90 to 100 mol% of the above-mentioned units based on the compound represented by formula F and the above-mentioned based on the compound having oxygen relative to all units contained in the polymer. Alkylene glycol monomer unit. The dispersion of claim 1 or 2, wherein the polar solvent is water, ketone, ester or amide. The dispersion of claim 1 or 2, wherein the above-mentioned polar solvent is methyl ethyl ketone, cyclohexanone, γ-butyrolactone, 3-methoxy-N,N-dimethylpropamide or N- Methyl-2-pyrrolidone. Such as the dispersion of claim 1 or 2, wherein the cumulative 50% particle size of the above-mentioned powder on a volume basis is 0.05~6 μm. The dispersion of claim 1 or 2, wherein the content of the above-mentioned tetrafluoroethylene polymer is 5 to 60 mass%. The dispersion liquid of Claim 1 or 2, wherein the ratio of the content of the above-mentioned dispersant to the content of the above-mentioned tetrafluoroethylene polymer is 0.25 or less.