Modified fluororesin material, material for circuit substrate, laminated body for circuit substrate, circuit substrate, and method for producing modified fluororesin material

Abstract

Provided is a novel modified fluororesin material having low linear expansion, a material for a circuit board, a laminate for a circuit board, a circuit board, and a method for producing a modified fluororesin material. A modified fluororesin material includes a modified fluororesin including a tetrafluoroethylene unit, a modified monomer unit based on a modified monomer capable of copolymerization with tetrafluoroethylene, and a tertiary carbon, the tertiary carbon being 0.001 to 0.100 mol% relative to the total of the tetrafluoroethylene unit and the modified monomer unit, and the linear expansion at 20 to 200°C is reduced by 5% or more compared to a non-modified fluororesin material including a tetrafluoroethylene unit and a modified monomer unit based on a modified monomer capable of copolymerization with tetrafluoroethylene and not including a tertiary carbon.

Description

Technical Field

[0001] This invention relates to modified fluoropolymer materials, materials for circuit boards, laminates for circuit boards, circuit boards, and methods for manufacturing modified fluoropolymer materials. Background Technology

[0002] With the increasing speed of communication, materials with low dielectric constant and low loss are required for circuit boards used in electrical equipment, electronic equipment, and communication equipment.

[0003] Patent document 1 describes a high-frequency printed circuit board obtained by laminating fluoropolymer (FEP) and copper film, and irradiating the fluoropolymer with ionizing rays in a molten state to improve adhesion.

[0004] Patent document 2 describes a high-frequency printed circuit board having a dielectric layer on both sides of an intermediate layer made of glass cloth, wherein a resin layer made of fluoropolymer (FEP) is disposed thereon.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-8260

[0008] Patent Document 2: Japanese Patent Application Publication No. 2015-8286 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] The purpose of this invention is to provide a novel modified fluororesin material with low linear expansion, a material for circuit boards, a laminate for circuit boards, a circuit board, and a method for manufacturing the modified fluororesin material.

[0011] Methods for solving problems

[0012] This invention relates to a modified fluoropolymer material comprising a modified fluoropolymer, wherein the modified fluoropolymer comprises tetrafluoroethylene units, modified monomer units based on a modified monomer capable of copolymerizing with tetrafluoroethylene, and tertiary carbon, wherein the total amount of the tertiary carbon relative to the tetrafluoroethylene units and the modified monomer units is 0.001 mol% to 0.100 mol%.

[0013] Compared with unmodified fluoropolymer materials containing tetrafluoroethylene units and modified monomer units based on modified monomers capable of copolymerizing with tetrafluoroethylene and not containing tertiary carbon, the linear expansion rate of the modified fluoropolymer material is reduced by more than 5% at 20°C to 200°C.

[0014] Compared with the above-mentioned unmodified fluoropolymer material, the modified fluoropolymer material preferably has a linear expansion rate that is reduced by more than 10% at 20℃ to 200℃.

[0015] The aforementioned tertiary carbon is preferably -CF2CF, which is present in the aforementioned modified fluoropolymer. * The F*-bonded carbon atom in the structure shown by (-CF2-)CF2-.

[0016] The modified monomers mentioned above are preferably monomers containing perfluorovinyl groups.

[0017] The monomer having perfluorovinyl groups is preferably selected from at least one group consisting of perfluoro(alkyl vinyl ethers), hexafluoropropylene, and perfluoroallyl ethers.

[0018] The modified fluororesin material described above preferably also includes inorganic fillers.

[0019] The inorganic filler is preferably selected from at least one of the group consisting of silica, alumina, titanium dioxide and talc.

[0020] The modified fluoropolymer material described above preferably also includes a resin (excluding the modified fluoropolymer material described above).

[0021] The resins mentioned above (excluding the modified fluororesins mentioned above) are preferably selected from at least one of the group consisting of poly(p-phenylenebenzoxazole), polybenzimidazole, polyimide, epoxy resin and polytetrafluoroethylene.

[0022] The present invention also relates to a material for a circuit board comprising the above-mentioned modified fluororesin material.

[0023] The preferred material for the aforementioned circuit board is a sheet.

[0024] The preferred material for the circuit board is a sheet with a thickness of 5μm to 3000μm.

[0025] The present invention also relates to a laminate for a circuit board having a metal layer (A1) and a layer (B) comprising the aforementioned material for a circuit board.

[0026] The metal constituting the metal layer (A1) is preferably copper.

[0027] The laminate used for the circuit board is preferably a sheet with a thickness of 10 μm to 3500 μm.

[0028] The present invention also relates to a circuit board having a metal layer (A2) and a layer (B) comprising the aforementioned circuit board material.

[0029] The metal constituting the metal layer (A2) is preferably copper.

[0030] The circuit board is preferably a sheet with a thickness of 10μm to 3500μm.

[0031] The circuit board described above is preferably a printed circuit board.

[0032] This invention also relates to a manufacturing method for producing the aforementioned modified fluororesin material.

[0033] It includes the following steps (1): irradiating a fluororesin, which is a copolymer of a tetrafluoroethylene unit and a modified monomer unit based on a modified monomer that can copolymerize with tetrafluoroethylene, with radiation at an irradiation temperature that is at least 5°C lower than the melting point of the fluororesin.

[0034] The above-mentioned step (1) is preferably a step of irradiating the above-mentioned fluororesin with at least one of the group consisting of inorganic fillers and resins (excluding the above-mentioned fluororesin) with the above-mentioned radiation.

[0035] The preferred radiation dose is 10 kGy to 250 kGy.

[0036] The aforementioned radiation is preferably electron beams.

[0037] This invention also relates to a manufacturing method for producing the aforementioned modified fluororesin material.

[0038] It includes the following step (2): mixing the above-mentioned modified fluoropolymer with at least one selected from the group consisting of inorganic fillers and resins (excluding the above-mentioned modified fluoropolymer).

[0039] The effects of the invention

[0040] According to the present invention, a novel modified fluororesin material with low linear expansion coefficient, a material for circuit boards, a laminate for circuit boards, a circuit board, and a method for manufacturing the modified fluororesin material can be provided. Detailed Implementation

[0041] In this specification, "organic group" means a group containing one or more carbon atoms, or a group formed by removing one hydrogen atom from an organic compound.

[0042] Examples of this "organic group" include:

[0043] Alkyl groups that can have more than one substituent

[0044] Alkenes that can have more than one substituent

[0045] Alkyne groups can have more than one substituent.

[0046] Cycloalkyl groups can have more than one substituent.

[0047] Cycloalkenyl groups can have more than one substituent.

[0048] Cycloalbenzene groups can have more than one substituent.

[0049] Aryl groups can have more than one substituent.

[0050] Aryl groups can have more than one substituent.

[0051] Non-aromatic heterocyclic groups that can have more than one substituent

[0052] Heteroaryl groups that can have more than one substituent

[0053] cyano,

[0054] formyl group,

[0055] RaO-、

[0056] RaCO-、

[0057] RaSO2-、

[0058] RaCOO-、

[0059] RaNRaCO-、

[0060] RaCONRa-、

[0061] RaOCO-、

[0062] RaOSO2-, and

[0063] RaNRbSO2-

[0064] (In these formulas, Ra is independently...)

[0065] Alkyl groups that can have more than one substituent

[0066] Alkenes that can have more than one substituent

[0067] Alkyne groups can have more than one substituent.

[0068] Cycloalkyl groups can have more than one substituent.

[0069] Cycloalkenyl groups can have more than one substituent.

[0070] Cycloalbenzene groups can have more than one substituent.

[0071] Aryl groups can have more than one substituent.

[0072] Aryl groups can have more than one substituent.

[0073] It can be a non-aromatic heterocyclic group with more than one substituent, or

[0074] Heteroaryl groups can have more than one substituent.

[0075] Rb is independently H or may be an alkyl group having more than one substituent.

[0076] As the aforementioned organic group, it is preferable to have an alkyl group having one or more substituents.

[0077] The present invention will be described in detail below.

[0078] The modified fluororesin material of the present invention comprises a modified fluororesin containing tetrafluoroethylene [TFE] units, modified monomer units based on modified monomers capable of copolymerizing with TFE, and tertiary carbon, wherein the total amount of the tertiary carbon relative to the TFE units and the modified monomer units is 0.001 mol% to 0.100 mol%. The modified fluororesin material of the present invention, comprising a modified fluororesin containing TFE units, the modified monomer units, and a specific amount of tertiary carbon, thus exhibits characteristics of low deformation and low linear expansion.

[0079] The linear expansion coefficient varies depending on the type of bonds present in the substance; substances with covalent bonds have a smaller linear expansion coefficient compared to substances with weaker bonds such as intermolecular forces. The modified fluororesin of this invention contains tertiary carbons. The presence of tertiary carbons implies that the modified fluororesin has a cross-linked structure. A cross-linked structure is a three-dimensional network structure in which molecular chains are bonded together by strong covalent bonds; it is believed that the presence of this covalent network suppresses the linear expansion coefficient.

[0080] The content of the tertiary carbon is preferably 0.005 mol% or more, more preferably 0.008 mol% or more, and preferably 0.080 mol% or less, more preferably 0.060 mol% or less, and even more preferably 0.030 mol% or less, relative to the total of the TFE unit and the modified monomer unit.

[0081] The aforementioned tertiary carbon is preferably -CF2CF, which is present in the aforementioned modified fluoropolymer. * The F*-bonded carbon atom in the structure shown by (-CF2-)CF2-.

[0082] The above-mentioned modified fluororesin was subjected to 19 By measuring the peak intensities (integral values ​​of the peaks) of A to C using F-NMR, the content of the aforementioned tertiary carbon can be calculated using the following formula.

[0083] 19 F-NMR measurement conditions

[0084] Measuring apparatus: solid 19 F-NMR measuring device, manufactured by BRUKER Corporation.

[0085] Measurement conditions: 282MHz (CF2 of modified fluoropolymer was used as -120ppm)

[0086] 30kHz rotation speed

[0087] Peak Intensity A

[0088] The peak observed at a chemical shift of -80 (-74 to -85) ppm originates from the -O-CF group of the perfluoro(alkyl vinyl ether) [PAVE] as a modified monomer. * 2- and -CF * 3 of 5 CF * peak intensity

[0089] Peak Intensity B

[0090] The peak observed at a chemical shift of -120 (-84 to -150) ppm, i.e., the five CFs of PAVE. * With 4 CFs from TFE * Intensity of overlapping peaks

[0091] Peak Intensity C

[0092] The peak observed at a chemical shift of -183 (-178 to -191) ppm originates from tertiary carbon -CF2CF * (-CF2-)CF2- of F * peak intensity

[0093] Calculation formula

[0094] Tertiary carbon content (mol%) = 100 × (peak intensity C) ÷ {(peak intensity A ÷ 5) + [peak intensity B - peak intensity A] ÷ 4 + (peak intensity C)}

[0095] When the modified monomer is a monomer other than PAVE, it can also be obtained through... 19 The content of tertiary carbon was determined by F-NMR.

[0096] As for the aforementioned modified monomers, there are no particular limitations as long as they can copolymerize with TFE. Examples include hexafluoropropylene [HFP], fluoroalkyl vinyl ethers, fluoroalkyl ethylene, and general formula (100): CH2=CFRf 101 (where Rf) 101 Fluorinated monomers, fluoroalkyl allyl ethers, etc., are shown as straight-chain or branched fluoroalkyl groups with 1 to 12 carbon atoms.

[0097] As the above-mentioned fluoroalkyl vinyl ether, it is preferred, for example, to be at least one selected from the group consisting of:

[0098] General formula (110): CF2 = CF - ORf 111

[0099] (where Rf) 111 The symbol represents a perfluorinated organic group. (The fluorinated monomer is indicated by the symbol ).

[0100] General formula (120): CF2=CF-OCH2-Rf 121

[0101] (where Rf) 121 Fluorinated monomers (representing perfluoroalkyl groups with 1 to 5 carbon atoms);

[0102] General formula (130): CF2=CFOCF2ORf 131

[0103] (where Rf) 131 Fluorine-containing monomers, including straight-chain or branched perfluoroalkyl groups with 1 to 6 carbon atoms, cyclic perfluoroalkyl groups with 5 to 6 carbon atoms, and straight-chain or branched perfluorooxyalkyl groups with 2 to 6 carbon atoms containing 1 to 3 oxygen atoms.

[0104] General formula (140): CF2=CFO(CF2CF(Y 141 )O) m (CF2) n F

[0105] (where Y) 141 This represents a fluorine atom or a trifluoromethyl group. m is an integer from 1 to 4. n is an integer from 1 to 4. (This refers to) fluorine-containing monomers; and

[0106] General formula (150): CF2=CF-O-(CF2CFY) 151 -O) n -(CFY 152 ) m -A 151

[0107] (where Y) 151 This indicates a fluorine atom, a chlorine atom, a -SO2F group, or a perfluoroalkyl group. Perfluoroalkyl groups may contain ether oxygen and a -SO2F group. n represents an integer from 0 to 3. n Y atoms 151 They can be the same or different. Y 152 Represents a fluorine atom, a chlorine atom, or a -SO2F group. m represents an integer from 1 to 5. m Y atoms 152 They can be the same or different. A 151 Indicates -SO2X 151 -COZ 151 or -POZ 152 Z 153 X 151Represents F, Cl, Br, I, -OR 151 or -NR 152 R 153 Z 151 Z 152 and Z 153 Same or different, indicating -NR 154 R 155 or -OR 156 R 151 R 152 R 153 R 154 R 155 and R 156 The same or different indicates H, ammonium, alkali metal, alkyl, aryl, or sulfonyl groups that may contain fluorine atoms.

[0108] In this specification, "perfluorinated organic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are replaced by fluorine atoms. The aforementioned perfluorinated organic group may contain ether oxygen.

[0109] As a fluorinated monomer represented by general formula (110), Rf can be cited as an example. 111 It is a fluorinated monomer of a perfluoroalkyl group having 1 to 10 carbon atoms. The preferred number of carbon atoms in the perfluoroalkyl group is 1 to 5.

[0110] Examples of perfluorinated organic groups in general formula (110) include perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, and perfluorohexyl.

[0111] Other examples of fluorinated monomers that can be represented by the general formula (110) include:

[0112] In the above general formula (110),

[0113] Rf 111 It is a perfluorinated (alkoxyalkyl) monomer with 4 to 9 carbon atoms;

[0114] Rf 111 It is the following formula:

[0115] [Chemistry 1]

[0116]

[0117] (In the formula, m represents 0 or an integer from 1 to 4.) Fluorinated monomers containing the groups shown;

[0118] Rf 111 It is the following formula:

[0119] [Chemistry 2]

[0120]

[0121] (In the formula, n represents an integer from 1 to 4.) Fluorine-containing monomers with the groups shown; etc.

[0122] As a fluorinated monomer represented by general formula (110), a perfluoro (alkyl vinyl ether) [PAVE] is preferred, and general formula (160) is more preferred: CF2=CF-ORf 161

[0123] (where Rf) 161 Represents perfluoroalkyl groups with 1 to 10 carbon atoms. (The fluorinated monomer is indicated by Rf.) 161 Preferably, it is a perfluoroalkyl group having 1 to 5 carbon atoms.

[0124] As a fluoroalkyl vinyl ether, it is preferably selected from at least one of the groups consisting of fluorinated monomers represented by general formulas (160), (130) and (140).

[0125] As the fluorinated monomer (PAVE) represented by general formula (160), it is preferably selected from at least one of the group consisting of perfluoro(methyl vinyl ether) [PMVE], perfluoro(ethyl vinyl ether) [PEVE] and perfluoro(propyl vinyl ether) [PPVE], and more preferably from at least one of the group consisting of perfluoro(methyl vinyl ether) and perfluoro(propyl vinyl ether).

[0126] As the fluorinated monomer represented by general formula (130), it is preferably selected from at least one of the group consisting of CF2=CFOCF2OCF3, CF2=CFOCF2OCF2CF3 and CF2=CFOCF2OCF2CF2OCF3.

[0127] As the fluorinated monomer represented by general formula (140), it is preferably selected from at least one of the group consisting of CF2=CFOCF2CF(CF3)O(CF2)3F, CF2=CFO(CF2CF(CF3)O)2(CF2)3F and CF2=CFO(CF2CF(CF3)O)2(CF2)2F.

[0128] As the fluorinated monomer represented by general formula (150), it is preferably selected from at least one of the group consisting of CF2=CFOCF2CF2SO2F, CF2=CFOCF2CF(CF3)OCF2CF2SO2F, CF2=CFOCF2CF(CF2CF2SO2F)OCF2CF2SO2F and CF2=CFOCF2CF(SO2F)2.

[0129] Rf is preferred as the fluorinated monomer represented by general formula (100). 101 A fluorinated monomer that is a straight-chain fluoroalkyl group, preferably Rf 101It is a straight-chain perfluoroalkyl fluorinated monomer. Rf 101 The number of carbon atoms is preferably 1 to 6. Examples of fluorinated monomers represented by general formula (100) include CH2=CFCF3, CH2=CFCF2CF3, CH2=CFCF2CF2CF3, CH2=CFCF2CF2CF2H, CH2=CFCF2CF2CF2CF3, CHF=CHCF3 (E form), CHF=CHCF3 (Z form), etc., among which 2,3,3,3-tetrafluoropropylene represented by CH2=CFCF3 is preferred.

[0130] As a fluoroalkyl ethylene, it is preferred

[0131] General formula (170): CH2=CH-(CF2) n -X 171

[0132] (where X) 171 Fluoroalkyl ethylene represented by H or F, n being an integer from 3 to 10, more preferably selected from CH2=CH-C4F9 and CH2=CH-C6F9. 13 At least one of the groups.

[0133] Examples of fluoroalkyl allyl ethers mentioned above include...

[0134] General formula (180): CF2=CF-CF2-ORf 111

[0135] (where Rf) 111 The symbol represents a perfluorinated organic group. The fluorinated monomer is indicated by .

[0136] Rf of general formula (180) 111 Rf of general formula (110) 111 Same. As Rf 111 Preferably, it is a perfluoroalkyl group having 1 to 10 carbon atoms or a perfluoroalkoxyalkyl group having 1 to 10 carbon atoms. As a fluoroalkyl allyl ether represented by general formula (180), it is preferably selected from at least one of the group consisting of CF2=CF-CF2-O-CF3, CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7 and CF2=CF-CF2-O-C4F9, more preferably from at least one of the group consisting of CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7 and CF2=CF-CF2-O-C4F9, and even more preferably from CF2=CF-CF2-O-CF2CF2CF3.

[0137] As the modified monomers mentioned above, monomers having perfluorovinyl groups are preferred from the perspective of further reducing the deformation of modified fluoropolymer materials and further reducing the linear expansion rate. More preferably, at least one monomer is selected from the group consisting of perfluoro(alkyl vinyl ether) (PAVE), hexafluoropropylene (HFP), and perfluoroallyl ether. More preferably, at least one monomer is selected from the group consisting of PAVE and HFP. From the perspective of suppressing the deformation of modified fluoropolymer materials during solder processing, PAVE is particularly preferred.

[0138] The modified fluoropolymer preferably contains at least 0.1% by mass of the modified monomer units, more preferably at least 1.0% by mass, and even more preferably at least 1.1% by mass. Furthermore, the total amount of the modified monomer units is preferably 30% by mass or less of all monomer units, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 10% by mass or less.

[0139] The amount of the above-mentioned modified monomer units is determined by... 19 The determination was performed using F-NMR.

[0140] When the modified fluoropolymer is a modified PFA containing TFE and PAVE units, it is preferable to include 0.1% to 12% by mass of PAVE units relative to all polymer units. The amount of PAVE units relative to all polymer units is more preferably 0.3% by mass or more, further preferably 0.7% by mass or more, even more preferably 1.0% by mass or more, particularly preferably 1.1% by mass or more, and even more preferably 8.0% by mass or less, further preferably 6.5% by mass or less, particularly preferably 6.0% by mass or less.

[0141] It should be noted that the quantities of the above PAVE units are obtained through... 19 The determination was performed using F-NMR.

[0142] When the modified fluoropolymer is a modified FEP containing TFE and HFP units, the mass ratio of TFE units to HFP units (TFE / HFP) is preferably 70–99 / 1–30 (mass%). More preferably, the mass ratio (TFE / HFP) is 85–95 / 5–15 (mass%).

[0143] The modified FEP described above contains at least 1% by mass, preferably at least 1.1% by mass, of HFP units from all monomer units.

[0144] The modified FEP described above preferably includes TFE units, HFP units, and perfluoro(alkyl vinyl ether) [PAVE] units.

[0145] As a PAVE unit included in the above-mentioned modified FEP, an example can be the same unit as the PAVE unit constituting the above-mentioned modified PFA. Among them, PPVE is preferred.

[0146] The modified PFA described above does not contain HFP units, and therefore differs from the modified FEP, which contains PAVE units, in this respect.

[0147] When the modified FEP described above includes TFE, HFP, and PAVE units, the preferred mass ratio (TFE / HFP / PAVE) is 70–99.8 / 0.1–25 / 0.1–25 (mass%). Within this range, excellent heat resistance and chemical resistance are observed.

[0148] The above-mentioned mass ratio (TFE / HFP / PAVE) is more preferably 75-98 / 1.0-15 / 1.0-10 (mass%).

[0149] The modified FEP described above comprises HFP units and PAVE units, which together account for more than 1% by mass, preferably more than 1.1% by mass, of all monomer units.

[0150] The modified FEP containing TFE, HFP and PAVE units preferably has HFP units comprising less than 25% by mass of all monomer units.

[0151] If the content of HFP units is within the above range, a modified fluoropolymer material with excellent heat resistance can be obtained.

[0152] The content of HFP units is more preferably 20% by mass or less, more preferably 18% by mass or less, and particularly preferably 15% by mass or less. Furthermore, the content of HFP units is preferably 0.1% by mass or more, more preferably 1% by mass or more, and particularly preferably 2% by mass or more.

[0153] It should be noted that the content of HFP units can be determined by... 19 The determination was performed using F-NMR.

[0154] The content of PAVE units is more preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 3% by mass or less. Furthermore, the content of PAVE units is preferably 0.1% by mass or more, more preferably 1% by mass or more. It should be noted that the content of PAVE units can be determined by… 19 The determination was performed using F-NMR.

[0155] The modified FEP described above may also contain other olefinic monomer (α) units.

[0156] As for other olefinic monomer (α) units, there are no particular limitations as long as they are monomer units that can copolymerize with TFE, HFP, and PAVE. Examples include fluorinated olefinic monomers such as vinyl fluoride [VF], vinylidene fluoride [VdF], chlorotrifluoroethylene [CTFE], and ethylene [Et]; and non-fluorinated olefinic monomers such as ethylene, propylene, and alkyl vinyl ethers.

[0157] When the modified FEP described above contains TFE units, HFP units, PAVE units and other olefinic monomer (α) units, the mass ratio (TFE / HFP / PAVE / other olefinic monomer (α)) is preferably 70-98 / 0.1-25 / 0.1-25 / 0.1-25 (mass%).

[0158] The modified FEP described above contains monomer units other than TFE units, which together account for 1% or more, preferably 1.1% or more, of all monomer units.

[0159] The modified fluoropolymers described above are preferably the modified PFA and the modified FEP described above. In other words, the modified PFA and the modified FEP described above can also be used in combination. The mass ratio of the modified PFA to the modified FEP described above (modified PFA / modified FEP) is preferably 9 / 1 to 3 / 7, more preferably 9 / 1 to 5 / 5.

[0160] The modified fluoropolymer material of the present invention, compared with an unmodified fluoropolymer material containing TFE units and modified monomer units based on modified monomers capable of copolymerizing with TFE and without tertiary carbon, exhibits a linear expansion rate of at least 5% lower at 20°C to 200°C. Consequently, the warpage of the modified fluoropolymer material is reduced. Compared with the unmodified fluoropolymer material, the linear expansion rate of the modified fluoropolymer material at 20°C to 200°C is preferably reduced by at least 10%, more preferably by at least 13%, further preferably by at least 15%, and particularly preferably by at least 20%.

[0161] The linear expansion rate described above was determined using the method described in the examples below.

[0162] The unmodified fluoropolymer material described above preferably has the same composition as the modified fluoropolymer material described above, except that it does not contain tertiary carbon. The unmodified fluoropolymer material may also be the fluoropolymer material used in the manufacturing method described later before irradiation.

[0163] Depending on the requirements, the modified fluororesin material of the present invention may contain other components. Examples of other components include fillers, crosslinking agents, antistatic agents, heat stabilizers, foaming agents, foaming nucleating agents, antioxidants, surfactants, photopolymerization initiators, anti-wear agents, surface modifiers, resins (excluding the aforementioned modified fluororesins), liquid crystal polymers, and other additives.

[0164] The modified fluororesin material of the present invention may include inorganic fillers as the other components mentioned above. By including inorganic fillers, electrical properties, strength, heat resistance, etc., can be improved. The modified fluororesin material of the present invention can be a composite material comprising the above-mentioned modified fluororesin and inorganic fillers.

[0165] The inorganic fillers mentioned above are not particularly limited and can include, for example, silica (more specifically, crystalline silica, fused silica, spherical fused silica, etc.), titanium dioxide, zirconium oxide, zinc oxide, tin oxide, silicon nitride, silicon carbide, boron nitride, calcium carbonate, calcium silicate, potassium titanate, aluminum nitride, indium oxide, aluminum oxide, antimony oxide, cerium oxide, magnesium oxide, iron oxide, and tin-doped indium oxide (ITO). Additionally, minerals such as montmorillonite, talc, mica, boehmite, kaolin, montmorillonite, calcareous silicate, vermiculite, and sericite can be cited. Other inorganic fillers include carbon compounds such as carbon black, acetylene black, Ketjen black, and carbon nanotubes; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; and various types of glass such as glass beads, glass sheets, and glass spheres.

[0166] One or more inorganic fillers can be used as the aforementioned inorganic fillers.

[0167] In addition, inorganic fillers can be used directly as powders or as substances dispersed in resins.

[0168] As the aforementioned inorganic filler, from the perspective of further improving electrical properties, strength, and heat resistance, at least one of the following is preferred: free silica, alumina, titanium dioxide, and talc. More preferably, at least one of the following is preferred: free silica, alumina, and titanium dioxide. Silica with low specific gravity and low dielectric constant is particularly preferred. By containing silica, the coefficient of thermal expansion of the fluororesin material can be kept low. Furthermore, this effect can suppress substrate warping, and is therefore preferred. Moreover, the peel strength of the coating layer can also be improved.

[0169] The shape of the aforementioned inorganic filler is not particularly limited, and can be, for example, granular, spherical, flake-like, needle-like, columnar, conical, truncated pyramidal, polyhedral, or hollow. Particularly preferred are spherical, cubic, basin-like, disc-like, octahedral, flake-like, rod-like, plate-like, pole-like, tetrapod-like, and hollow shapes; more preferably, spherical, cubic, octahedral, plate-like, or hollow shapes. By forming it into a flake-like or needle-like shape and arranging anisotropic fillers, higher adhesion can be obtained. Spherical fillers, due to their small surface area, can reduce the impact on the properties of fluoropolymers, and furthermore, they exhibit less thickening when mixed with liquids, making them preferable from this perspective.

[0170] The average particle size of the aforementioned inorganic filler is preferably 0.1 μm to 20 μm. If the average particle size is within this range, there is less agglomeration, resulting in good surface roughness. The lower limit of the aforementioned average particle size is more preferably 0.2 μm, and even more preferably 0.3 μm. The upper limit of the aforementioned average particle size is more preferably 5 μm, and even more preferably 2 μm.

[0171] The average particle size mentioned above was determined by laser diffraction and scattering.

[0172] The maximum particle size of the aforementioned inorganic filler is preferably 10 μm or less. If the maximum particle size is 10 μm or less, there is less agglomeration and the dispersion is good. Furthermore, the surface roughness of the obtained fluoropolymer material can be reduced. The maximum particle size is more preferably 5 μm or less. Regarding the maximum particle size, SEM (scanning electron microscope) images were taken, and the particle size was determined using SEM image analysis software from image data of 200 randomly selected particles.

[0173] The aforementioned inorganic filler can be a surface-treated inorganic filler, such as an inorganic filler surface-treated with an organosilicon compound. By surface-treating with the aforementioned organosilicon compound, the dielectric constant of the inorganic filler can be reduced.

[0174] There are no particular limitations on the organosilicon compounds used, and any existing known organosilicon compounds may be used. For example, it is preferable to include at least one selected from the group consisting of silane coupling agents and organosilazanes.

[0175] Regarding the surface treatment amount of the aforementioned organosilicon compound, the preferred reaction amount of the surface treatment agent on the surface of the inorganic filler is per unit surface area (nm). 2 The number of particles is 0.1 to 10, more preferably 0.3 to 7.

[0176] The specific surface area of ​​the aforementioned inorganic filler, for example, based on the BET method, is preferably 1.0 m². 2 / g~25.0m 2 / g, more preferably 1.0m 2 / g~10.0m 2 / g, further preferably 2.0m 2 / g~6.4m 2 / g. By maintaining a specific surface area within the above range, the inorganic filler in the fluoropolymer material exhibits less aggregation and a smoother surface, thus it is preferred.

[0177] Furthermore, the modified fluoropolymer material of the present invention may also include a resin (excluding the aforementioned modified fluoropolymer) as one of the other components. By including the aforementioned resin, effects such as increased strength and reduced linear expansion can be expected. The modified fluoropolymer material of the present invention can be a composite material comprising the aforementioned modified fluoropolymer and a resin (excluding the aforementioned modified fluoropolymer).

[0178] Examples of the aforementioned resins include, for example, thermoplastic polyimides, thermosetting polyimides, polyamic acid as a precursor to them, poly(p-phenylenebenzoxazole), polybenzimidazole, and polyetherketone resin.

[0179] Examples of diamines or polycarboxylic acid dianhydrides that form polyamic acids include those described in paragraphs

[0020] ,

[0019] ,

[00125] ,

[0055] , and

[0057] of Japanese Patent Application Publication No. 5766125. Among these, combinations of aromatic diamines such as 4,4'-diaminodiphenyl ether and 2,2-bis[4-(4-aminophenoxy)phenyl]propane with aromatic polycarboxylic acid dianhydrides such as pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, and 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride are preferred. The diamine and the polycarboxylic acid dianhydride or their derivatives may be used individually or in combination of two or more.

[0180] In the case of a thermoplastic resin or a resin that cures to become a thermoplastic resin, a resin with a melting point of 280°C or higher is preferred as the thermoplastic resin. This makes it easier to suppress expansion (foaming) caused by heat when exposed to an atmosphere equivalent to solder reflow in films or the like, where the resin is a thermoplastic material.

[0181] Alternatively, the aforementioned resin can also be a resin composed of a non-thermally fusible polymer. Non-thermally fusible resins such as polytetrafluoroethylene (PTFE) and resins composed of cured thermosetting resins are dispersed in the fluororesin in the same manner as the aforementioned inorganic fillers.

[0182] Examples of thermosetting resins include epoxy resins, acrylic resins, phenolic resins, polyester resins, polyolefin resins, modified polyphenylene ether resins, polyfunctional cyanate resins, polyfunctional maleimide-cyanate resins, polyfunctional maleimide resins, vinyl ester resins, urea resins, diallyl phthalate resins, melamine resins, guanidine resins, melamine-urea cocondensation resins, and fluoropolymers with reactive groups (excluding the aforementioned modified fluoropolymers). Among these, epoxy resins, acrylic resins, bismaleimide resins, and modified polyphenylene ether resins are preferred as thermosetting resins from the perspective of their usefulness in printed circuit board applications; epoxy resins and modified polyphenylene ether resins are particularly preferred. A single thermosetting resin may be used alone, or two or more may be used in combination.

[0183] The epoxy resins mentioned above are not particularly limited to any epoxy resin used to form various substrate materials for printed circuit boards. Specifically, examples include naphthalene-type epoxy resins, cresol-phenolic varnish-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, cresol-phenolic varnish-type epoxy resins, phenolic phenolic varnish-type epoxy resins, alkylphenol-phenolic varnish-type epoxy resins, aralkyl-type epoxy resins, biphenol-type epoxy resins, dicyclopentadiene-type epoxy resins, trihydroxyphenylmethane-type epoxy compounds, epoxides of condensates of phenols and aromatic aldehydes having phenolic hydroxyl groups, diglycidyl ethers of bisphenols, diglycidyl ethers of naphthalene glycol, glycidyl ethers of phenols, diglycidyl ethers of alcohols, and triglycidyl isocyanurate, etc.

[0184] In addition to those listed above, various glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, and oxidized epoxy resins can also be used. Furthermore, phosphorus-modified epoxy resins can also be used. One type of epoxy resin can be used alone, or two or more types can be used in combination. Particularly from the perspective of excellent curing properties, epoxy resins with two or more epoxy groups per molecule are preferred.

[0185] The weight-average molecular weight of the epoxy resin is preferably 100 to 1,000,000, more preferably 1,000 to 100,000. If the weight-average molecular weight of the epoxy resin is within the above range, the film formed from the modified fluororesin material exhibits excellent interlayer adhesion to other materials (such as metals). The weight-average molecular weight of the epoxy resin is determined by gel permeation chromatography (GPC).

[0186] Examples of the aforementioned bismaleimide resins include the resin composition (BT resin) comprising bisphenol A type cyanate resin and bismaleimide compound disclosed in Japanese Patent Application Publication No. 7-70315, the invention disclosed in International Publication No. 2013 / 008667, and the resin composition disclosed in the background art of the invention.

[0187] When using a thermosetting resin as the above-mentioned resin, the modified fluororesin material of the present invention may include a curing agent. Examples of curing agents include thermosetting agents (melamine resin, polyurethane resin, etc.) and epoxy curing agents (phenolic varnish-type phenolic resin, isophthalic acid dihydrazide, adipate dihydrazide, etc.).

[0188] From the perspective of superior performance in terms of increased strength and reduced linear expansion, the resin is preferably selected from at least one of the group consisting of poly(p-phenylenebenzoxazole), polybenzimidazole, polyimide, epoxy resin and polytetrafluoroethylene.

[0189] The content of the other components is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less, relative to the modified fluoropolymer material described above. If the content of these other components is too high, the electrical properties may deteriorate. Furthermore, the content of these other components is preferably 15% by mass or more relative to the modified fluoropolymer material described above.

[0190] The modified fluororesin material described above is preferably composed solely of the modified fluororesin described above.

[0191] The modified fluororesin material of the present invention can be suitably manufactured by a manufacturing method including step (1), wherein step (1) involves irradiating a fluororesin, which is a copolymer comprising TFE units and modified monomer units based on modified monomers capable of copolymerizing with TFE, with radiation at an irradiation temperature at least 5°C lower than the melting point of the fluororesin. The present invention also provides the above-described manufacturing method.

[0192] The irradiation temperature is preferably more than 20°C lower than the melting point of the fluororesin, more preferably more than 25°C lower, and even more preferably more than 35°C lower. Furthermore, it is preferably 0°C or higher, more preferably room temperature or higher, even more preferably 80°C or higher, even more preferably 100°C or higher, particularly preferably 150°C or higher, and most preferably 200°C or higher.

[0193] Examples of radiation include electron beams, ultraviolet rays, gamma rays, X-rays, neutron rays, and high-energy ions. Among these, electron beams are preferred due to their excellent penetrating power, high dose rate, and suitability for industrial production.

[0194] There are no particular limitations on the method of irradiation, and methods using existing and known radiation irradiation devices can be cited as examples.

[0195] The preferred radiation dose is 10 kGy to 250 kGy. If the dose is too low, the amount of free radicals generated in the cross-linking reaction will be insufficient, and the cross-linking effect may not be fully achieved. If the dose is too high, low molecular weighting may occur due to main chain cleavage, resulting in a significant decrease in mechanical strength.

[0196] The radiation dose is more preferably 20 kGy or more, further preferably 30 kGy or more, more preferably 100 kGy or less, further preferably 90 kGy or less, and particularly preferably 80 kGy or less.

[0197] There are no particular restrictions on the radiation environment, but it is preferable to have an oxygen concentration of less than 1000 ppm, more preferably in the absence of oxygen, and even more preferably in a vacuum or in an atmosphere of inactive gases such as nitrogen, helium or argon.

[0198] As a modifying monomer capable of copolymerizing with TFE in the aforementioned fluoropolymer, examples can be the same modifying monomers used in the modified fluoropolymer materials of the present invention.

[0199] As the aforementioned fluoropolymer, a fluoropolymer capable of melt processing is preferred. In this specification, "capable of melt processing" means that the polymer can be melted and processed using existing processing equipment such as extruders and injection molding machines.

[0200] As for the aforementioned fluororesin, from the perspective of further reducing the deformation of the modified fluororesin material and further reducing the linear expansion rate, tetrafluoroethylene [TFE] / monomer copolymer having perfluorovinyl groups is preferred, more preferably at least one of the group consisting of TFE / perfluoro(alkyl vinyl ether) [PAVE] copolymer "PFA", TFE / hexafluoropropylene [HFP] copolymer [FEP] and TFE / perfluoroallyl ether copolymer, and even more preferably at least one of the group consisting of PFA and FEP. From the perspective of high melting point and no deformation during solder processing, PFA is particularly preferred.

[0201] The PFA described above is a copolymer containing TFE units and PAVE units, or it can be a copolymer consisting only of TFE units and PAVE units. The monomer units constituting the PFA described above and their amounts are the same as those in the modified PFA described above.

[0202] The melting point of the PFA is preferably 280°C to 322°C. More preferably, it is 290°C or higher, and even more preferably, it is 315°C or lower.

[0203] The melting point mentioned above is the temperature corresponding to the maximum value in the heat of fusion curve when heated at a rate of 10°C / min using a differential scanning calorimeter (DSC).

[0204] The glass transition temperature (Tg) of the PFA is preferably 70°C to 110°C. More preferably, it is 80°C or higher, and even more preferably, it is 100°C or lower.

[0205] The glass transition temperature mentioned above was obtained by dynamic viscoelasticity measurement.

[0206] The aforementioned PFA can be manufactured, for example, by appropriately mixing monomers, polymerization initiators, and other additives that will become its constituent units and carrying out existing known methods such as emulsion polymerization or suspension polymerization.

[0207] The aforementioned FEP is a copolymer containing TFE and HFP units. The monomer units constituting the aforementioned FEP and their amounts are the same as those of the aforementioned modified FEP.

[0208] The melting point of the aforementioned FEP is preferably between 200°C and 322°C. If the melting point is too low, the effects of radiation exposure may not be fully realized. If the melting point is too high, depolymerization due to main chain cleavage may occur, potentially leading to a significant decrease in mechanical strength. More preferably, the melting point is above 200°C, even more preferably above 220°C, more preferably below 300°C, and even more preferably below 280°C. The melting point is the temperature corresponding to the maximum value in the heat of fusion curve obtained by heating at a rate of 10°C / min using a differential scanning calorimeter (DSC).

[0209] The glass transition temperature (Tg) of the aforementioned FEP is preferably 60°C to 110°C, more preferably 65°C or higher, and even more preferably 100°C or lower. The aforementioned glass transition temperature is a value obtained by dynamic viscoelasticity measurement.

[0210] The aforementioned FEP can be manufactured, for example, by appropriately mixing monomers, polymerization initiators, and other additives that will become its constituent units and carrying out existing known methods such as emulsion polymerization, solution polymerization, and suspension polymerization.

[0211] The fluoropolymers described above are preferably the PFA and FEP described above. In other words, the PFA and FEP described above can also be used in combination. The mass ratio of the PFA to the FEP described above (PFA / HFP) is preferably 9 / 1 to 3 / 7, more preferably 9 / 1 to 5 / 5.

[0212] The above mixture can be prepared by known methods such as mixing and melting two or more fluororesins with different melting points (melt mixing), or mixing resin dispersions after emulsion polymerization and recovering the resin by precipitation with acids such as nitric acid. Melt mixing can be carried out at a temperature above the melting point of the fluororesin with the highest melting point among the two or more fluororesins with different melting points.

[0213] The melt flow rate (MFR) of the aforementioned fluoropolymer at 372°C is preferably 0.1 g / 10 min to 100 g / 10 min. When the MFR is within this range, the effect of radiation exposure is significant. More preferably, the MFR is 0.5 g / 10 min or more, more preferably 80 g / 10 min or less, and even more preferably 40 g / 10 min or less. The aforementioned MFR is obtained according to ASTM D1238 using a melt flow index tester (manufactured by Yasuda Seiki Co., Ltd.) as the mass (g / 10 min) of polymer flowing out of a nozzle with an inner diameter of 2 mm and a length of 8 mm every 10 minutes at 372°C and a load of 5 kg.

[0214] In the manufacture of a modified fluoropolymer material that also contains the other components mentioned above, the mixture of the fluoropolymer and the other components can be irradiated with the radiation, or the modified fluoropolymer can be mixed with the other components.

[0215] As another component mentioned above, a modified fluororesin material comprising at least one of the group consisting of inorganic fillers and resins (excluding the modified fluororesin mentioned above) can be suitably manufactured, for example, by a manufacturing method in which step (1) involves irradiating the mixture of the fluororesin and at least one of the group consisting of inorganic fillers and resins (excluding the modified fluororesin mentioned above) with the radiation.

[0216] As other components mentioned above, a modified fluororesin material comprising at least one of the group consisting of inorganic fillers and resins (excluding the modified fluororesin described above) can also be suitably manufactured by a manufacturing method comprising step (2) of mixing the modified fluororesin with at least one of the group consisting of inorganic fillers and resins (excluding the modified fluororesin described above). The present invention also provides the above-described manufacturing method.

[0217] The modified fluororesin mentioned above can be the modified fluororesin obtained in the above step (1).

[0218] The above manufacturing methods may further include a step of molding the above-mentioned fluororesin or modified fluororesin material. Irradiation with the above-mentioned radiation may also be performed after molding.

[0219] There are no particular limitations on the molding method; well-known methods such as extrusion molding, injection molding, transfer molding, blow molding, and compression molding can be cited. These molding methods can be appropriately selected according to the shape of the target modified fluoropolymer material.

[0220] The present invention also provides a circuit board material comprising the modified fluororesin material of the present invention described above.

[0221] The materials used for the circuit board described above may consist solely of the modified fluororesin material described above.

[0222] The shape of the material used for the circuit board is not particularly limited, but a sheet is preferred.

[0223] The thickness of the above-mentioned sheet is preferably 5μm to 3000μm, more preferably 5μm to 2000μm.

[0224] The material used for the circuit board can be a material with surface modification on one or both sides. Surface modification is preferred from the perspective of improving adhesion to metal layers such as copper foil.

[0225] The specific methods for surface modification are not particularly limited and can be carried out by any known method. Specifically, corona discharge treatment, glow discharge treatment, plasma discharge treatment, sputtering-based treatment, etc., can be used. For example, in addition to controlling the surface free energy by introducing oxygen, nitrogen, hydrogen, etc. into the discharge atmosphere, the surface to be modified can be exposed to an atmosphere of inactive gas (such as nitrogen, helium, argon, etc.) containing organic compounds, and a high-frequency voltage can be applied between the electrodes to induce discharge, thereby generating active species on the surface. Then, functional groups of organic compounds can be introduced or polymerizable organic compounds can be grafted and polymerized to perform surface modification.

[0226] The above surface modification is particularly suitable for cases where the material used for the circuit board is a sheet.

[0227] The material for circuit boards of the present invention is used in circuit boards, and is particularly preferred for use in the insulating layer of circuit boards.

[0228] As the aforementioned circuit substrate, a printed circuit board is preferred. The aforementioned printed circuit board can be a rigid substrate, a flexible substrate, or a combination of rigid and flexible substrates.

[0229] The aforementioned circuit board is preferably a high-frequency circuit board. A high-frequency circuit board is a circuit board that can operate even at high frequency bands. The aforementioned high-frequency band can be a band of 1 GHz or higher, preferably a band of 3 GHz or higher, and more preferably a band of 5 GHz or higher. There is no particular upper limit, and it can be a band of 100 GHz or lower.

[0230] The circuit board material of the present invention can also be used for circuit boards for fifth-generation mobile communication systems.

[0231] The present invention also relates to a laminate for a circuit board having a metal layer (A1) and a layer (B) comprising the circuit board material of the present invention described above.

[0232] The metal constituting the metal layer (A1) is preferably at least one selected from the group consisting of copper, stainless steel, aluminum, iron and their alloys, more preferably at least one selected from the group consisting of copper, stainless steel and aluminum, and even more preferably copper.

[0233] Examples of stainless steels mentioned above include austenitic stainless steel, martensitic stainless steel, and ferritic stainless steel.

[0234] The metal layer (A1) can be a layer formed by sputtering, vacuum evaporation, electroplating, chemical plating, etc., or it can be a layer formed by metal foil.

[0235] When the metal layer (A1) is formed of a metal foil, the metal foil can be bonded to the layer (B) by hot pressing to form the metal layer (A1).

[0236] The thickness of the metal layer (Al) can be, for example, 2 μm to 200 μm, preferably 5 μm to 50 μm.

[0237] The metal layer (A1) can be applied to only one side of the layer (B) or to both sides.

[0238] Layer (B) comprises the material for the circuit board of the present invention. Layer (B) is preferably a sheet comprising the material for the circuit board of the present invention. Layer (B) can be prefabricated separately from the metal layer (A1), or it can be formed by laminating the above-mentioned fluororesin and the metal layer (A1) and then irradiating the fluororesin with radiation.

[0239] The above surface modification can also be applied to one or both sides of layer (B).

[0240] The thickness of layer (B) can be, for example, 1 μm to 1 mm, preferably 1 μm to 500 μm. More preferably, it is 150 μm or less, and even more preferably 100 μm or less.

[0241] The laminate of the present invention may further include layers other than the metal layer (A1) and layer (B). From the perspective of electrical properties and thin film formation, it is preferable that the aforementioned other layers are not provided on the side of layer (B) opposite to the metal layer (A1).

[0242] The laminate of the present invention is preferably a sheet. The thickness of the laminate of the present invention is preferably 10 μm to 3500 μm, more preferably 20 μm to 3000 μm.

[0243] The laminate of the present invention can be used, for example, as a metal-clad laminate for forming a circuit board.

[0244] The present invention also relates to a circuit board having a metal layer (A2) and a layer (B) comprising the circuit board material of the present invention described above.

[0245] As for the metal that constitutes the metal layer (A2), the same metal as the metal that constitutes the metal layer (A1) can be cited, and the same metal thickness can also be cited.

[0246] Layer (B) is the same as layer (B) in the laminate of the present invention.

[0247] The metal layer (A2) preferably forms the circuit. There is no particular limitation on the method for forming the circuit pattern; examples include: forming an unpatterned metal layer on layer (B) and then patterning it through etching or similar processes; directly forming the metal layer at the desired location of the circuit pattern on layer (B); combining both methods; and so on. In any case, existing known methods can be used.

[0248] The circuit board of the present invention may be a circuit board in which the metal layer (A1) is patterned in the laminate of the present invention.

[0249] The metal layer (A2) can be applied to only one side of the layer (B) or to both sides. Alternatively, the above-described surface modification can be applied to one or both sides of the layer (B).

[0250] Furthermore, the circuit board of the present invention may also include other layers besides the metal layer (A2) and layer (B). From the perspective of electrical characteristics and thin-film fabrication, it is preferable that the aforementioned other layers are not provided on the side of layer (B) opposite to the metal layer (A2).

[0251] The circuit board of the present invention is preferably a sheet. The thickness of the circuit board of the present invention is preferably 10 μm to 3500 μm, more preferably 20 μm to 3000 μm.

[0252] The circuit board of the present invention is preferably a printed circuit board. Regarding the printed circuit board, as described above.

[0253] The circuit board of the present invention is preferably a high-frequency circuit board. Regarding the high-frequency circuit board, as described above.

[0254] The circuit board of the present invention is preferably a circuit board for a fifth-generation mobile communication system.

[0255] Example

[0256] The invention will now be described in more detail by way of examples, but the invention is not limited to these examples.

[0257] Various physical properties were determined by the following methods.

[0258] (Monomer content)

[0259] The content of each monomer unit is obtained through 19 The determination was performed using F-NMR.

[0260] (MFR)

[0261] According to ASTM D1238, using a melt flow index tester (manufactured by Yasuda Seiki Co., Ltd.), determine the mass (g / 10 min) of polymer flowing out of a nozzle with an inner diameter of 2 mm and a length of 8 mm every 10 minutes at 372°C and a load of 5 kg.

[0262] (Glass transition temperature)

[0263] The results were obtained by performing dynamic viscoelasticity measurements using a DVA-220 (manufactured by IT Measurement and Control Co., Ltd.).

[0264] As a sample test piece, a compression-molded sheet with a length of 25 mm, a width of 5 mm, and a thickness of 0.2 mm was used. The temperature of the peak value of tanδ was measured at a heating rate of 2℃ / min and a frequency of 10 Hz. The temperature of the peak value of tanδ was taken as the glass transition temperature.

[0265] (Melting point)

[0266] The melting point is defined as the temperature corresponding to the maximum value in the fusion heat curve obtained by using a differential scanning calorimeter (DSC) at a heating rate of 10 °C / min.

[0267] (Linear expansion rate)

[0268] The TMA was determined using a TMA-7100 (manufactured by Hitachi High-Tech Science Corporation) based on the following compression mode.

[0269] [Compression Mode Measurement]

[0270] As a sample, a compression-molded sheet with a length of 6 mm, a width of 6 mm, and a thickness of 2 mm was used. The linear expansion rate was determined by measuring the displacement of the sample at a temperature of 20°C to 200°C while applying a load of 49 mN and heating at a rate of 2°C / min.

[0271] (Content of tertiary carbon)

[0272] By conducting 19 It is determined by F-NMR measurements. The calculation method is as described above.

[0273] Example 1

[0274] The tetrafluoroethylene (TFE) / perfluoro(propyl vinyl ether) (PPVE) copolymer [TFE / PPVE = 94.5 / 5.5 (mass%), MFR 30 g / 10 min, melting point 302 °C] (PFA1) was processed into a 2 mm thick sheet using a hot press molding machine, and then cut into test pieces with a width of 20 mm and a length of 20 mm.

[0275] The obtained test piece was placed in an electron beam irradiation container of an electron beam irradiation device (manufactured by NHV Corporation), and nitrogen gas was added to create a nitrogen atmosphere inside the container. The temperature inside the container was set to 255°C. After the temperature stabilized, the test piece was irradiated with electron beams at an acceleration voltage of 3000 kV and an irradiation dose intensity of 20 kGy / 5 min to obtain a modified fluoropolymer material. The linear expansion coefficient of this modified fluoropolymer material, cut into samples with a thickness of 2 mm and a width of 6 mm and a length of 6 mm, was 165 ppm, representing a 14% decrease in linear expansion coefficient compared to the unirradiated sample (Comparative Example 1). The tertiary carbon content relative to the combined TFE and PPVE units was 0.010 mol%.

[0276] The modified fluororesin material obtained above is bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the sheet to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0277] Example 2

[0278] Except that the electron beam irradiation temperature was set to 245°C, the modified fluoropolymer material was obtained in the same manner as in Example 1. The linear expansion coefficient of this modified fluoropolymer material was 178 ppm, representing a 7% decrease in linear expansion coefficient compared to the unirradiated sample (Comparative Example 1), and the tertiary carbon content was 0.007 mol% relative to the total TFE and PPVE units.

[0279] The modified fluororesin material obtained above is bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the sheet to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0280] Example 3

[0281] Except that the electron beam irradiation temperature was set to 270°C, the modified fluoropolymer material was obtained in the same manner as in Example 1. The linear expansion coefficient of this modified fluoropolymer material was 183 ppm, representing a 6% decrease in linear expansion coefficient compared to the unirradiated sample (Comparative Example 1), and the tertiary carbon content was 0.046 mol% relative to the total TFE and PPVE units.

[0282] The modified fluororesin material obtained above is bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the sheet to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0283] Example 4

[0284] In addition to using a blend of 80% by mass tetrafluoroethylene (TFE) / perfluoropropyl vinyl ether (PPVE) copolymer [TFE / PPVE = 98.5 / 1.5 (mass%), MFR: 14 g / 10 min, melting point: 306 °C] and 20% by mass silica (Admafine SC2500-SQ manufactured by Admatechs, average particle size: 0.5 μm, specific surface area: 6.1 m²), the blend also incorporates other components. 2 Except for replacing PFA1 with PFA2 ( / g), a modified fluoropolymer material was obtained in the same manner as in Example 1. The linear expansion coefficient of this modified fluoropolymer material was 103 ppm, which was 24% lower than that of the sample not irradiated with electron beams (Comparative Example 2), and the content of tertiary carbon was 0.011 mol% relative to the total of TFE and PPVE units.

[0285] The modified fluororesin material obtained above is bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the sheet to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0286] Example 5

[0287] The tetrafluoroethylene (TFE) / perfluoro(propyl vinyl ether) (PPVE) copolymer [TFE / PPVE = 98.5 / 1.5 (wt%), MFR 15 g / 10 min, melting point 306 °C] (PFA3) was melt-extruded into a film with a thickness of 0.056 mm, and then cut into test pieces with a width of 280 mm and a length of 370 mm.

[0288] The obtained test piece was placed on an aluminum frame (270mm wide × 330mm deep × 25mm high). Aluminum weights (width: 20mm × 270mm × 6mm, 88g; length: 20mm × 330mm × 6mm, 106g) were fixed around the membrane with clamps on all four sides. Under tension, the membrane was placed in an electron beam irradiation container (manufactured by NHV Corporation), and nitrogen gas was added to create a nitrogen atmosphere inside the container. The temperature inside the container was set to 255℃. After the temperature stabilized, the test piece was irradiated with electron beams at an acceleration voltage of 3000kV and an irradiation dose intensity of 20kGy / 5min, yielding the modified fluoropolymer material. The linear expansion coefficient of the modified fluoropolymer material, cut into strips 2 mm wide and 18 mm long with a thickness of 0.056 mm, was 188 ppm, which was 12% lower than that of the sample not irradiated with electron beams (Comparative Example 3). The content of tertiary carbon was 0.013 mol relative to the total of TFE and PPVE units.

[0289] The modified fluororesin material obtained above is bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the sheet to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0290] Example 6

[0291] PFA1 was processed into a sheet with a thickness of 0.215 mm using a thermoforming machine, and then cut into strips with a width of 12.5 mm and a length of 130 mm to obtain test pieces. The test pieces were then bonded to a 100 mm square copper foil by vacuum pressing (using a vacuum pump to heat the sheet to 320°C under reduced pressure, apply a pressure of 15 kN and hold for 5 minutes).

[0292] The obtained PFA sheet with copper foil was irradiated with electron beams in the same manner as in Example 1 to obtain a laminate for circuit board.

[0293] Comparative Example 1

[0294] PFA1 was processed into a 2mm thick sheet using a thermoforming machine, and then cut into strips 6mm wide and 6mm long to obtain the test piece. The linear expansion coefficient of this test piece was 191ppm, and the tertiary carbon content relative to the total of the TFE and PPVE units was 0.000 mol%.

[0295] The above-mentioned test piece was bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the piece to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0296] Comparative Example 2

[0297] PFA2 was processed into a 2mm thick sheet using a thermoforming machine, and then cut into strips 6mm wide and 6mm long to obtain the test piece. The linear expansion coefficient of this test piece was 135ppm, and the tertiary carbon content relative to the total of the TFE and PPVE units was 0.000 mol%.

[0298] The above-mentioned test piece was bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the piece to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0299] Comparative Example 3

[0300] PFA3 was processed into a 0.056 mm thick film using a melt extrusion molding machine, and then cut into strips 2 mm wide and 18 mm long to obtain test pieces. The linear expansion coefficient of the test pieces was 213 ppm, and the tertiary carbon content relative to the total of TFE and PPVE units was 0.000 mol%.

[0301] The above-mentioned test piece was bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the piece to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0302] Comparative Example 4

[0303] Except that the electron beam irradiation temperature was 320°C and the irradiation dose was 40 kGy, the modified fluoropolymer material was obtained in the same manner as in Example 1. The linear expansion coefficient of this modified fluoropolymer material was 193 ppm, which was 1% lower than that of the sample without electron beam irradiation (Comparative Example 1), and the tertiary carbon content was 0.115 mol% relative to the total of TFE and PPVE units.

[0304] The modified fluororesin material obtained above is bonded to a 100mm square copper foil by vacuum pressing (using a vacuum pump to heat the sheet to 320°C under reduced pressure, apply 15kN pressure and hold for 5 minutes) to obtain a laminate for circuit board.

[0305] The results above show that electron beam irradiation can reduce the linear expansion rate of modified fluororesin materials, resulting in good laminates for circuit boards.

Claims

1. A modified fluoropolymer material comprising a modified fluoropolymer, said modified fluoropolymer comprising tetrafluoroethylene units, modified monomer units based on a modified monomer capable of copolymerizing with tetrafluoroethylene, and tertiary carbon, said tertiary carbon comprising, in a total amount of 0.008 mol% to 0.030 mol% relative to the tetrafluoroethylene units and said modified monomer units. Compared to unmodified fluoropolymer materials containing tetrafluoroethylene units and modified monomer units based on modified monomers capable of copolymerizing with tetrafluoroethylene, and which do not contain tertiary carbon, the modified fluoropolymer material exhibits a linear expansion rate reduced by more than 10% at temperatures ranging from 20°C to 200°C. The tertiary carbon is -CF2C present in the modified fluororesin. The F in the structure shown by (-CF2-)CF2- Bonded carbon atoms.

2. The modified fluoropolymer material according to claim 1, wherein, The modified monomer is a monomer with perfluorovinyl groups.

3. The modified fluoropolymer material according to claim 2, wherein, The monomer having perfluorovinyl groups is selected from at least one of the groups consisting of perfluoro(alkylvinyl ethers), hexafluoropropylene, and perfluoroallyl ethers.

4. The modified fluoropolymer material according to claim 3, wherein, The monomer having perfluorinated vinyl groups is a perfluorinated (propyl vinyl ether).

5. The modified fluoropolymer material according to claim 1 or 2, further comprising inorganic fillers.

6. The modified fluoropolymer material according to claim 5, wherein, The inorganic filler is selected from at least one of the following groups: silica, alumina, titanium dioxide, and talc.

7. The modified fluoropolymer material according to claim 1 or 2, further comprising a resin other than the modified fluoropolymer.

8. The modified fluoropolymer material according to claim 7, wherein, The resin other than the modified fluororesin is at least one selected from the group consisting of poly(p-phenylenebenzoxazole), polybenzimidazole, polyimide, epoxy resin and polytetrafluoroethylene.

9. A material for a circuit board comprising the modified fluoropolymer material according to any one of claims 1 to 8.

10. The material for the circuit board according to claim 9, wherein it is a sheet.

11. The material for circuit boards according to claim 9 or 10, wherein it is a sheet with a thickness of 5 μm to 3000 μm.

12. A laminate for a circuit board, comprising: a metal layer (A1) and a layer (B) comprising the material for a circuit board according to any one of claims 9 to 11.

13. The laminate for a circuit board according to claim 12, wherein, The metal that makes up the metal layer (A1) is copper.

14. The laminate for circuit board according to claim 12 or 13, wherein it is a sheet with a thickness of 10 μm to 3500 μm.

15. A circuit board comprising: a metal layer (A2) and a layer (B) comprising the material for a circuit board according to any one of claims 9 to 11.

16. The circuit board according to claim 15, wherein, The metal that makes up the metal layer (A2) is copper.

17. The circuit board according to claim 15 or 16, wherein it is a sheet with a thickness of 10 μm to 3500 μm.

18. The circuit board according to claim 15 or 16, wherein it is a printed circuit board.

19. A manufacturing method for producing the modified fluoropolymer material according to any one of claims 1 to 8. It includes the following steps (1): irradiating a fluororesin, which is a copolymer of a tetrafluoroethylene unit and a modified monomer unit based on a modified monomer capable of copolymerizing with tetrafluoroethylene, with radiation at an irradiation temperature at least 5°C lower than the melting point of the fluororesin.

20. The manufacturing method according to claim 19, wherein, The step (1) is a step of irradiating the mixture of the fluororesin with at least one of the group consisting of inorganic fillers and resins other than the fluororesin.

21. The manufacturing method according to claim 19 or 20, wherein, The radiation dose is 10 kGy to 250 kGy.

22. The manufacturing method according to claim 19 or 20, wherein, The radiation is electron beam.

23. A manufacturing method for producing the modified fluoropolymer material according to any one of claims 1 to 8. It includes the following step (2): mixing the modified fluororesin with at least one selected from the group consisting of inorganic fillers and resins other than the modified fluororesin.

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