Composition for foam molding, foamed molded body, foamed electric wire, method for manufacturing a foamed molded body, and method for manufacturing a foamed electric wire

Abstract

The present invention provides a foam molding composition capable of sufficiently miniaturizing air bubbles, a foam molded body, a foamed electric wire, a method for manufacturing a foam molded body, and a method for manufacturing a foamed electric wire. [Solution] A fluororesin (A) that can be melt-molded has a thermal decomposition temperature of 300°C or higher, a solubility parameter (SP value) of 8 to 15, and a specific surface area of ​​24 to 100 m². 2 A foam molding composition comprising compound (B) in a quantity of / g.

Description

[Technical Field]

[0001] This disclosure relates to a foam molding composition, a foam molded article, a foamed electric wire, a method for manufacturing a foam molded article, and a method for manufacturing a foamed electric wire. [Background technology]

[0002] Fluoropolymers are widely used in a variety of applications due to their excellent heat resistance and chemical resistance.

[0003] Foam molding is a known method for reducing the weight and improving the electrical properties of fluororesins. In foam molding, fine bubbles can be formed by adding a substance that acts as a foaming nucleation site (foaming nucleating agent) (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-028640 [Patent Document 2] Special Publication No. 2010-539252 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, conventional methods sometimes failed to sufficiently refine the bubbles.

[0006] The purpose of this disclosure is to provide a foam molding composition, a foam molded body, a foamed electric wire, a method for manufacturing a foam molded body, and a method for manufacturing a foamed electric wire, which can sufficiently miniaturize air bubbles. [Means for solving the problem]

[0007] This disclosure (1) provides a melt-mold fluororesin (A) and a fluororesin having a thermal decomposition temperature of 300°C or higher, a solubility parameter (SP value) of 8 to 15, and a specific surface area of ​​24 to 100 m².2 It is a foaming composition containing compound (B) per / g.

[0008] The present disclosure (2) is the foaming composition according to the present disclosure (1), wherein the compound (B) is a compound containing at least one partial structure selected from the group consisting of an aromatic ring and a phosphate group.

[0009] The present disclosure (3) is the foaming composition according to the present disclosure (1) or (2), wherein the compound (B) is a compound containing one or more aromatic rings having 6 to 14 carbon atoms or a salt thereof.

[0010] The present disclosure (4) is the foaming composition according to any one of the present disclosures (1) to (3), wherein the compound (B) is at least one compound selected from the group consisting of a phosphate ester and a salt thereof, and a phosphate ester complex compound.

[0011] The present disclosure (5) is the foaming composition according to any one of the present disclosures (1) to (4), wherein the compound (B) is an alkali metal salt or an alkaline earth metal salt.

[0012] The present disclosure (6) is the foaming composition according to any one of the present disclosures (1) to (5), wherein the compound (B) is a compound represented by any one of the following formulas (1) to (3).

Chemical formula

Chemical formula

Chemical formula

[0013] This disclosure (7) is R of formulas (1) to (3) above. 1 , R 2 , R 21 , R 22 , R 31 , R 33 This is the foam molding composition described in (6) of this disclosure, which is an alkyl group having 1 to 8 carbon atoms.

[0014] The present disclosure (8) is a foam molding composition according to the present disclosure (6) or (7), wherein X in formulas (1) to (3) is at least one selected from the group consisting of sodium, potassium, rubidium, calcium, and barium.

[0015] Disclosure (9) is a foam molding composition according to any one of Disclosures (6) to (8), wherein compound (B) is a compound represented by formula (1).

[0016] The present disclosure (10) is a foam molding composition according to the present disclosure (9), wherein compound (B) is at least one selected from the group consisting of 2,2'-methylenebis(4,6-di-t-butylphenyl)sodium phosphate and 2,2'-methylenebis(4,6-di-t-butylphenyl)barium phosphate.

[0017] This disclosure (11) provides that the specific surface area of ​​compound (B) is 25 to 50 m². 2 The foam molding composition is one of the foam molding compositions described in any of (1) to (10) of this disclosure, which is / g.

[0018] Disclosure (12) is a foam molding composition according to any one of Disclosures (1) to (11), wherein the fluororesin (A) is at least one selected from the group consisting of tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene / ethylene copolymer.

[0019] The present disclosure (13) is a foam molding composition according to any one of the present disclosures (1) to (12), wherein the fluororesin (A) is at least one selected from the group consisting of tetrafluoroethylene / hexafluoropropylene copolymers and tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymers.

[0020] Disclosure (14) is a foam molding composition according to any one of Disclosures (1) to (13), wherein the fluororesin (A) is a fluororesin that has been treated with fluorination.

[0021] Disclosure (15) is a foam molding composition according to any of Disclosures (1) to (14) that is substantially free of fluorine-based low molecular weight compounds.

[0022] Disclosure (16) is a foamed molded article obtained from a foaming molded composition described in any of Disclosures (1) to (15).

[0023] This disclosure (17) is a foamed molded article according to this disclosure (16) that is substantially free of fluorinated low molecular weight compounds.

[0024] The present disclosure (18) is a foamed electric wire comprising a core wire and a covering material obtained from any of the foamed molding compositions described in the present disclosure (1) to (15) and covering the core wire.

[0025] This disclosure (19) is a foamed wire as described in this disclosure (18) that is substantially free of fluorine-based low molecular weight compounds.

[0026] The present disclosure (20) further comprises at least one selected from the group consisting of a jacket and a sheath, wherein the at least one selected from the group consisting of a jacket and a sheath includes at least one selected from the group consisting of fluororubber and fluororesin, and is a foamed electric wire according to the present disclosure (18) or (19).

[0027] Disclosure (21) is a method for producing a foamed molded article, which includes a step of foaming a foamed molding composition described in any of Disclosures (1) to (15).

[0028] This disclosure (22) is a method for manufacturing a foamed electric wire, which includes the step of coating a core wire with a foam molding composition described in any of this disclosure (1) to (15) to obtain a foamed electric wire. [Effects of the Invention]

[0029] According to this disclosure, it is possible to provide a foam molding composition capable of sufficiently miniaturizing bubbles, a foam molded article, a foamed electric wire, a method for manufacturing a foam molded article, and a method for manufacturing a foamed electric wire. [Modes for carrying out the invention]

[0030] The following provides a detailed explanation of this disclosure.

[0031] The foam molding composition of this disclosure comprises a melt-mold fluororesin (A) and a fluororesin with a thermal decomposition temperature of 300°C or higher, a solubility parameter (SP value) of 8 to 15, and a specific surface area of ​​24 to 100 m². 2 It contains compound (B) which is / g.

[0032] In the foam molding composition of this disclosure, compound (B) functions as a foaming nucleating agent, thereby enabling the formation of fine bubbles.

[0033] The fluororesin (A) is not particularly limited as long as it is a fluororesin that can be melt-molded, but examples include tetrafluoroethylene (TFE) / hexafluoropropylene (HFP) copolymer [FEP], TFE / perfluoro(alkyl vinyl ether) (PAVE) copolymer [PFA], TFE / ethylene copolymer [ETFE], chlorotrifluoroethylene (CTFE) / ethylene copolymer [ECTFE], polyvinylidene fluoride [PVdF], polychlorotrifluoroethylene [PCTFE], TFE / vinylidene fluoride (VdF) copolymer [VT], polyvinyl fluoride [PVF], TFE / VdF / CTFE copolymer [VTC], TFE / ethylene / HFP copolymer, TFE / HFP / VdF copolymer, etc. One or more of these can be used.

[0034] Examples of the above-mentioned PAVEs include perfluoro(methyl vinyl ether) [PMVE], perfluoro(ethyl vinyl ether) [PEVE], and perfluoro(propyl vinyl ether) [PPVE]. Among these, PPVE is preferred. One or more of these can be used.

[0035] The fluororesin (A) may have polymerization units based on other monomers in an amount that does not impair the essential properties of each fluororesin. Examples of other monomers that can be appropriately selected include TFE, HFP, ethylene, propylene, perfluoro(alkyl vinyl ether), perfluoroalkylethylene, hydrofluoroolefin, fluoroalkylethylene, perfluoro(alkyl allyl ether), etc. One or more of these can be used. The perfluoroalkyl group constituting the other monomer is preferably one having 1 to 10 carbon atoms.

[0036] Other monomers may be monomers having polar groups. Examples of monomers having polar groups include nonfluorine monomers having hydroxyl groups such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyisobutyl vinyl ether, hydroxycyclohexyl vinyl ether, and other hydroxyalkyl vinyl ethers; nonfluorine monomers having carboxyl groups such as acrylic acid, methacrylic acid, itaconic acid, succinic acid, fumaric acid, crotonic acid, maleic acid, citraconic acid, undecylenic acid, and acetylenedicarboxylic acid; itaconic anhydride (hereinafter also referred to as "IAH"), citraconic anhydride (hereinafter also referred to as "CAH"), 5-norbornene-2, Examples include nonfluorine monomers having acid anhydride residues such as 3-dicarboxylic acid anhydride (hereinafter also referred to as "NAH"), succinic anhydride, fumaric anhydride, and maleic anhydride; nonfluorine monomers having sulfo groups such as vinyl sulfonic acid; nonfluorine monomers having epoxy groups (glycidyl groups) such as glycidyl vinyl ether and glycidyl allyl ether; nonfluorine monomers having amino groups such as aminoalkyl vinyl ether and aminoalkyl allyl ether; nonfluorine monomers having amide groups such as (meth)acrylamide and methylolacrylamide; and nonfluorine monomers having nitrile groups such as acrylonitrile and methacrylonitrile.

[0037] Because of its excellent heat resistance, the fluororesin (A) is preferably at least one selected from the group consisting of TFE / HFP copolymers, TFE / PAVE copolymers, and TFE / ethylene copolymers, more preferably at least one selected from the group consisting of TFE / HFP copolymers and TFE / PAVE copolymers, and even more preferably a TFE / HFP copolymer. Furthermore, it is also preferable that it be a perfluororesin because it has superior electrical properties.

[0038] The TFE / HFP copolymer preferably has a TFE / HFP ratio of 80-97 / 3-20 by mass, and more preferably 84-92 / 8-16. The TFE / HFP copolymer may be a binary copolymer consisting of TFE and HFP, or it may be a terpolymer consisting of comonomers copolymerizable with TFE and HFP (for example, a TFE / HFP / PAVE copolymer). The TFE / HFP copolymer is also preferably a TFE / HFP / PAVE copolymer that contains polymerization units based on PAVE. The TFE / HFP / PAVE copolymer preferably has a mass ratio of 70-97 / 3-20 / 0.1-10 for TFE / HFP / PAVE, and more preferably 81-92 / 5-16 / 0.3-5.

[0039] The TFE / PAVE copolymer preferably has a TFE / PAVE ratio of 90-99 / 1-10 by mass, and more preferably 92-97 / 3-8.

[0040] The TFE / ethylene copolymer preferably has a TFE / ethylene molar ratio of 20-80 / 20-80, and more preferably 40-65 / 35-60. The TFE / ethylene copolymer may also contain other monomer components. In other words, the TFE / ethylene copolymer may be a binary copolymer consisting of TFE and ethylene, or it may be a tertiary copolymer consisting of TFE and a comonomer copolymerizable with ethylene (for example, a TFE / ethylene / HFP copolymer). The TFE / ethylene copolymer is also preferably a TFE / ethylene / HFP copolymer that contains polymerization units based on HFP. The TFE / ethylene / HFP copolymer is preferably composed of TFE / ethylene / HFP in a molar ratio of 40-65 / 30-60 / 0.5-20, and more preferably 40-65 / 30-60 / 0.5-10.

[0041] In this specification, "melt-moldable" preferably means that the melt flow rate (MFR) is 1 g / 10 min or more. The MFR of fluororesin (A) is more preferably 10 g / 10 min or more, even more preferably 15 g / 10 min or more, even more preferably 30 g / 10 min or more, particularly preferably 35 g / 10 min or more, and also preferably 100 g / 10 min or less, more preferably 70 g / 10 min or less, even more preferably 60 g / 10 min or less, and particularly preferably 45 g / 10 min or less. The above MFR values ​​were measured in accordance with ASTM D-1238 using a die with a diameter of 2.1 mm and a length of 8 mm, at 372°C and under a 5 kg load.

[0042] Fluororesin (A) can be synthesized by polymerizing monomer components using conventional polymerization methods, such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, and gas-phase polymerization. Chain transfer agents such as methanol may be used in the above polymerization reaction. Fluororesin (A) may also be produced by polymerization and isolation without the use of metal ion-containing reagents.

[0043] The fluororesin (A) is not particularly limited, but may have an end group such as -CF3 or -CF2H at at least one of the polymer main chain and polymer side chains, and is preferably one having an -CF3 end group. Fluororesins having these end groups are obtained by fluorination treatment. Unfluorinated fluororesins may have thermally and electrically unstable end groups such as -COOH, -CH2OH, -COF, and -CONH2 (hereinafter, such end groups are also referred to as "unstable end groups"). Such unstable end groups can be reduced by the fluorination treatment described above. It is preferable that fluororesin (A) has few or no such unstable end groups, and the total number of the four types of unstable end groups and the -CF2H end group is such that the carbon number is 1 × 10 6 It is more preferable that there be 50 or fewer per unit. If there are more than 50, molding defects may occur. It is more preferable that there be 20 or fewer of the above-mentioned unstable end groups, and even more preferable that there be 10 or fewer. In this specification, the number of unstable terminal groups is a value obtained from infrared absorption spectroscopy. It is also possible that the unstable terminal groups and -CF2H terminal groups are absent, and all are -CF3 terminal groups.

[0044] Fluorination treatment can be carried out by bringing an unfluorinated fluororesin into contact with a fluorine-containing compound. The fluorine-containing compound is not particularly limited, but examples include fluorine radical sources that generate fluorine radicals under fluorination treatment conditions. Examples of fluorine radical sources include F2 gas, CoF3, AgF2, UF6, OF2, N2F2, CF3OF, and halogenated fluorides (e.g., IF5, ClF3). One or more of these can be used. The fluorine radical source, such as F2 gas, may be at 100% concentration, but it is preferable to mix it with an inert gas and dilute it to 5-50% by mass, preferably 15-30% by mass, before use. Examples of the inert gas include nitrogen gas, helium gas, and argon gas, but nitrogen gas is preferred from an economic standpoint. The conditions for the fluorination treatment are not particularly limited, and the fluorine-containing compound may be brought into contact with the molten fluororesin. However, it is usually carried out at a temperature below the melting point of the fluororesin, preferably 20 to 220°C, and more preferably 100 to 200°C. The fluorination treatment is generally carried out for 1 to 30 hours, preferably 5 to 20 hours. The fluorination treatment preferably involves contacting an unfluorinated fluororesin with fluorine gas (F2 gas).

[0045] The fluororesin (A) does not need to be fluorinated. As mentioned above, unfluorinated fluororesins have end groups that are unstable in terms of thermal and electrical properties, but they have high core wire adhesion. Therefore, when performance such as core wire adhesion is required, it is preferable to use an unfluorinated fluororesin. Furthermore, the fluororesin (A) may be a combination of fluorinated and unfluorinated materials, or it may be fluorinated to the extent that an appropriate amount of unstable end groups remain.

[0046] While the fluororesin (A) is not particularly limited, it is desirable that it has a melting point of 200°C or higher, a molding temperature of 250°C or higher, and a thermal decomposition temperature of 300°C or higher, in order to obtain a foamed molded article with excellent heat resistance and a wide continuous use temperature range. Furthermore, a melting point of 250°C or higher is more preferable, and 320°C or lower is preferable. A molding temperature of 300°C or higher is more preferable, and 450°C or lower is preferable. A thermal decomposition temperature of 350°C or higher is more preferable, and 400°C or higher is even more preferable. The upper limit for the melting point, molding temperature, and thermal decomposition temperature is 600°C or lower. In this specification, the melting point is the temperature measured by a differential scanning calorimeter (DSC), the molding temperature is a generally recommended temperature suitable for molding, at which the material is fluid and does not undergo resin degradation such as discoloration, and the thermal decomposition temperature is the temperature at which the material loses 1% of its mass when heated in air at 10°C / min, as measured by TG (thermal weight change measurement). However, the mass loss due to the volatilization of contained water and crystal water observed between 100°C and 200°C is excluded. Fluidity means that the MFR at that temperature is 0.0001 g / 10 min or more.

[0047] To minimize signal loss in communication wires, the dielectric constant of the fluororesin (A) is preferably 3.0 or less, more preferably 2.5 or less, even more preferably 2.3 or less, and most preferably 2.1 or less. The lower limit is 1.0 or higher. Similarly, the dielectric loss tangent is preferably 0.01 or less, more preferably 0.002 or less, even more preferably 0.001 or less, and most preferably 0.0005 or less. The lower limit is 0.0001 or higher. The dielectric constant and dielectric loss tangent of fluororesin (A) are measured by the empty cylinder resonator method at a frequency of 6 GHz.

[0048] The content of fluororesin (A) is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, per 100 parts by mass of the foam molding composition. Even more preferably 90 parts by mass or more, even more preferably 95 parts by mass or more, and particularly preferably 98 parts by mass or more. The upper limit is preferably 99.999 parts by mass or less, and more preferably 99.990 parts by mass or less.

[0049] Compound (B) is a compound with a thermal decomposition temperature of 300°C or higher and a solubility parameter (SP value) of 8 to 15. Since a foamed molded article with excellent heat resistance and a wide continuous use temperature range can be obtained, the thermal decomposition temperature of compound (B) is preferably 350°C or higher, and more preferably 400°C or higher. The upper limit is preferably 600°C or lower. The thermal decomposition temperature can be measured in the same manner as for the fluororesin (A) described above.

[0050] In order to effectively achieve the effects of this disclosure, it is desirable that compound (B) is not melted at the molding temperature. For this reason, the melting point of compound (B) is preferably 200°C or higher, more preferably 300°C or higher, even more preferably 350°C or higher, and particularly preferably 400°C or higher. The melting point of compound (B) is the temperature that can be identified by the TGA peak during TG measurement. For example, if no peak is observed below 400°C, the melting point is considered to be above 400°C. Whether the compound has melted at the peak temperature can be confirmed by observation using a heating microscope or electric furnace.

[0051] Compound (B) has a solubility parameter (SP value) of 8 to 15, which allows for uniform dispersion of additive particles and enables uniform and fine foaming. Furthermore, it suppresses the generation of large particles due to re-aggregation of particles during foam molding, reducing surface irregularities on the wire caused by large particles and resulting in a smoother surface. The SP value of compound (B) is preferably 9 or higher, more preferably 10 or higher. It is also preferably 14 or lower, more preferably 13 or lower, and even more preferably 12 or lower. The SP value of compound (B) can be determined by Fedors' formula (Polym.Eng.Sci.,14[2],147(1974)).

[0052] Compound (B) has a specific surface area of ​​24-100 m². 2 The specific surface area is preferably 25 m² / g. 2 / g or more, more preferably 28m 2 / g or more, more preferably 30m 2 It is 1 / g or more, and preferably 80m 2 / g or less, more preferably 60m 2 / g or less, more preferably 50m 2 It is less than / g. The specific surface area of ​​compound (B) can be measured by the method described in the examples below.

[0053] Compound (B) is preferably pulverized. Pulverization can be carried out by a method and under conditions that can adjust the specific surface area to within the above range. For example, the type and conditions of the pulverizer can be appropriately selected. Examples of pulverizers that can be used include mortars, jet mills, hammer mills, ball mills, and pin mills. Alternatively, the specific surface area of ​​compound (B) may be adjusted to within the above range by classification. It is believed that when compound (B) is pulverized or classified, the particle size distribution becomes sharper, which can further suppress the generation of volatile matter.

[0054] Theoretically, using a foaming nucleating agent with a large specific surface area would facilitate the formation of fine bubbles. However, with general foaming nucleating agents that do not fall under compound (B) (for example, boron nitride), even increasing the specific surface area did not result in the formation of fine bubbles. This is thought to be because a larger specific surface area makes aggregation more likely, hindering the function of the foaming nucleating agent. On the other hand, compound (B) used in this application has a high thermal decomposition temperature and low volatility even with a large specific surface area. Therefore, when the molding temperature exceeds 300 degrees Celsius during fluororesin molding, the amount of volatilization is small, making it less likely to cause molding defects such as smoke or eye discharge. In addition, compound (B) is less prone to aggregation, making it less likely to generate large bubbles due to bubble coalescence, thus reducing the maximum bubble diameter and enabling the formation of fine foam. Due to these effects, the surface of the wire coating becomes smoother, and sparks and surface irregularities of the wire can be reduced. Furthermore, even under the same molding conditions, it is possible to produce wires with higher foaming and lower capacitance.

[0055] Compound (B) is preferably a compound containing at least one substructure selected from the group consisting of aromatic rings and phosphate ester groups. For example, if compound (B) contains an aromatic ring, it is preferably a compound containing one or more aromatic rings having 6 to 14 carbon atoms or a salt thereof. Furthermore, if compound (B) is a salt, it is preferably an alkali metal salt or an alkaline earth metal salt, and more preferably an alkali metal salt.

[0056] If compound (B) contains a phosphate ester group, it is preferable that it be at least one compound selected from the group consisting of phosphate esters and their salts, and phosphate ester complex compounds. Typical phosphate ester compounds that can be used as compound (B) are phosphate esters, phosphite esters, acidic phosphate esters, acidic phosphite esters, or salts thereof of ammonia, amines, melamines, alkali metals, or alkaline earth metals, and their specific structure is not particularly limited.

[0057] Specific examples of compound (B) containing a phosphate ester group include ethyl diphenyl phosphate, isopropyl diphenyl phosphate, n-butyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate, cetyl diphenyl phosphate, stearyl diphenyl phosphate, oleyl diphenyl phosphate, diphenyl acid phosphate, diphenyl (2-acryloyloxyethyl) phosphate, diphenyl (2-methacryloyloxyethyl) phosphate, trinaphthyl phosphate, trinonyl phenyl phosphate, tris(2,6-dimethylphenyl) phosphate, tetraphenyl resorcinol diphosphate, tetraphenyl hydroquinone diphosphate, tetraphenylbisphenol A diphosphate, tetra(2,6-dimethylphenyl) resorcinol diphosphate, tetra(2, Examples include acidic phosphate esters such as 6-dimethylphenyl)bisphenol A diphosphate, tetra(2,6-dimethylphenyl)biphenyl diphosphate, tetraphenylethylene glycol diphosphate, bis(2,6-dimethylphenyl)pentaerythritol diphosphate, and dixylenyl acid phosphate; or acidic phosphite esters; ethyl phosphate ammonium salt, mono-n-butyl phosphate sodium salt, diphenyl phosphate ammonium salt, diphenyl phosphate melamine salt, diphenyl phosphate piperazine salt, phenyl phosphate ammonium salt, dicresyl phosphate ethylenediamine salt, cresyl phosphate sodium salt, and dixylenyl phosphate melamine salt; or salts of acidic phosphite esters with ammonia, amine, melamine, alkali metals, or alkaline earth metals.

[0058] More specifically, examples include salts of phosphate esters such as sodium bis(4-t-butylphenyl) phosphate, sodium 2,2'-methylenebis(4,6-di-t-butylphenyl) phosphate, and barium 2,2'-methylenebis(4,6-di-t-butylphenyl) phosphate, as well as sodium 2-hydroxy-2-oxo-4,6,10,12-tetra-t-butyl-1,3,2-dibenzo[d,g]perhydrodioxaphosphalosine, barium bisphenol phosphate, sodium binaphthyl phosphate, and sodium bis(4-nitrophenyl) phosphate. Furthermore, the ester may be a monoester, diester, triester, or even more. These may be used individually or in combination of two or more.

[0059] Among these, aromatic phosphate esters are preferred, salts of aromatic phosphate esters are more preferred, and salts of aromatic phosphate esters having a cyclic structure are even more preferred. More preferably are salts of cyclic phosphate esters having a biphenyl structure, a binaphthyl structure, or a benzohydryl structure, however, these benzene rings and naphthalene rings may have an alkyl group or cycloalkyl group having 1 to 8 carbon atoms, or an aryl group, alkylaryl group, or arylalkyl group having 6 to 12 carbon atoms. The aromatic phosphate ester salt having the above-mentioned cyclic structure is preferably at least one of the aromatic cyclic phosphate ester salts represented by any of the following formulas (1) to (3).

[0060] [ka] [ka] [ka] (In the formula, R 1 , R 2 , R 3 , R 4 , R 21 , R 22 , R23 , R 24 , R 31 , R 32 , R 33 , R 34 R represents a hydrogen atom, an alkyl group or cycloalkyl group having 1 to 8 carbon atoms, or an aryl group, alkylaryl group, or arylalkyl group having 6 to 12 carbon atoms. 5 , R 6 (where 'n' represents a hydrogen atom or methyl group, 'n' represents an integer of 1 or 2, 'm' represents an integer from 0 to 2, and 'X' represents a metal with m+n valency.)

[0061] R 1 , R 2 , R 3 , R 4 , R 21 , R 22 , R 23 , R 24 , R 31 , R 32 , R 33 , R 34 Examples of alkyl groups represented by include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, 2-butyl, 3-butyl, amyl, isoamyl, 2-amyl, 3-amyl, hexyl, isohexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, and 3-octyl. Examples of cycloalkyl groups include cyclopentyl, cyclohexyl, and cycloheptyl. Among these, alkyl groups having 1 to 8 carbon atoms are preferred, alkyl groups having 1 to 4 carbon atoms are more preferred, and t-butyl groups are even more preferred.

[0062] R 1 , R 2 , R 3 , R 4 , R 21 , R 22 , R 23 , R 24 , R 31 , R 32 , R 33 , R 34Examples of aryl groups represented by include phenyl, naphthyl, and biphenyl. Examples of alkylaryl groups include 4-methylphenyl, 4-tertiary butylphenyl, and nonylphenyl. Examples of arylalkyl groups include benzyl, phenethyl, and cumyl.

[0063] R 1 , R 2 , R 21 , R 22 , R 31 , R 33 The alkyl group is preferably a C1-C8 alkyl group, more preferably a C1-C4 alkyl group, and even more preferably a t-butyl group. R 3 , R 4 , R 23 , R 24 , R 32 , R 34 A hydrogen atom is preferred. 5 , R 6 Hydrogen atoms are preferred.

[0064] Examples of metals represented by X include alkali metals such as lithium, sodium, potassium, and rubidium; alkaline earth metals such as magnesium, calcium, and barium; aluminum, zinc, and titanium. Among these, at least one of sodium, potassium, rubidium, calcium, and barium is preferred, and sodium and / or barium is more preferred.

[0065] The phosphate ester complex compound that can be used as compound (B) is a complex consisting of a metal and an organic compound having a phosphate ester, and its specific structure is not particularly limited.Examples of organic compounds that constitute this complex compound include bis(4,4',6,6'-tetra-t-butyl-2,2'-methylenediphenyl phosphate), 2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate, 2,2'-methylene-bis(4,6-di-methylphenyl) phosphate, 2,2'-methylene-bis(4,6-di-methylphenyl) phosphate, 2,2'-methylene-bis(4,6-di-ethylphenyl) phosphate, and 2,2'-methylene-bis(4-methyl-6-t- Butylphenyl) phosphate, 2,2'-methylene-bis(4-ethyl-6-t-butylphenyl) phosphate, 2,2'-ethylidene-bis(4,6-di-t-butylphenyl) phosphate, 2,2'-ethylidene-bis(4-i-propyl-6-t-butylphenyl) phosphate, 2,2'-ethylidene-bis(4-m-butyl-6-t-butylphenyl) phosphate, 2,2'-butylidene-bis(4,6-di-methylphenyl) phosphate, 2,2'-butylidene-bis(4,6-di-t-butyl Phenyl) phosphate, 2,2'-t-octylmethylene-bis(4,6-di-methylphenyl) phosphate, 2,2'-t-octylmethylene-bis(4,6-di-t-butylphenyl) phosphate, bis[2,2'-thiobis(4-ethyl-6-t-butylphenyl) phosphate], bis[2,2'-thiobis-(4,6-di-t-butylphenyl) phosphate], bis[2,2'-thiobis-(4,6-t-octylphenyl) phosphate], bis[2,2'-methylene-bis(4,6-di-t-butylphenyl] Examples include tris[2,2'-ethylene-bis(4,6-di-t-butylphenyl)phosphate], bis[(4,4'-dimethyl-6,6'-di-t-butyl-2,2'-biphenyl)phosphate], (4,4'-dimethyl-5,6'-di-t-butyl-2,2'-biphenyl)phosphate, tris[2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate], tris[2,2'-ethylene-bis(4,6-di-t-butylphenyl)phosphate], etc.

[0066] Examples of metals that constitute the phosphate ester complex compounds include aluminum, sodium, lithium, calcium, magnesium, and barium. These may be used individually or in combination of two or more. Among these, aromatic phosphate esters are preferred, cyclic aromatic phosphate esters are more preferred, and sodium complex compounds of aromatic cyclic phosphate esters are most preferred.

[0067] Among the compounds (B) described above, it is preferable that the compound is represented by any of the above formulas (1) to (3), more preferably that it is an aromatic cyclic phosphate salt represented by formula (1), even more preferably that it is 2,2'-methylenebis(4,6-di-t-butylphenyl)sodium phosphate represented by the following formula (4), more preferably that it is 2,2'-methylenebis(4,6-di-t-butylphenyl)barium phosphate represented by the following formula (5), and particularly preferably that it is 2,2'-methylenebis(4,6-di-t-butylphenyl)sodium phosphate.

[0068] [ka]

[0069] [ka]

[0070] The content of compound (B) is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.1 parts by mass or more, and preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, even more preferably 2 parts by mass or less, and particularly preferably 1.5 parts by mass or less, relative to the fluororesin (A). Setting the content of compound (B) above the lower limit makes it easier to form fine bubbles, and setting it below the upper limit can reduce the number of sparks.

[0071] The foam molding composition of this disclosure may contain a fluororesin (C) that does not fall under fluororesin (A), that is, a fluororesin that cannot be melt-molded. In this specification, "unable to melt mold" preferably means that the MFR is less than 1 g / 10 min. The MFR of fluororesin (C) is more preferably 0.1 g / 10 min or less, and more preferably 0.01 g / 10 min or less. The lower limit is not particularly limited. The above MFR values ​​were measured in accordance with ASTM D-1238 using a die with a diameter of 2.1 mm and a length of 8 mm, at 372°C and under a 5 kg load.

[0072] Examples of fluororesin (C) include polytetrafluoroethylene (PTFE). Other fluororesins such as FEP, PFA, ETFE, PCTFE, and PVDF, as exemplified in fluororesin (A), can also be used. One or more of these can be used. Among these, PTFE is preferred. Furthermore, for FEP and similar materials, if the MFR is less than 1 g / 10 min, it will be classified as fluororesin (C) (fluororesin that cannot be melt-molded), and if the MFR is 1 g / 10 min or more, it will be classified as fluororesin (A) (fluororesin that can be melt-molded).

[0073] In this disclosure, PTFE may be a tetrafluoroethylene [TFE] homopolymer, or a modified polytetrafluoroethylene [modified PTFE] obtained from TFE and a trace comonomer. TFE homopolymers are obtained by polymerizing tetrafluoroethylene (TFE) alone as the monomer. The trace comonomers in modified PTFE are not particularly limited as long as they are fluorine-containing compounds that can copolymerize with TFE, and include, for example, perfluoroolefins such as hexafluoropropene (HFP); perfluorovinyl ethers (PFVE) such as the various PAVEs mentioned above; fluorodioxoles, etc.; trifluoroethylene; vinylidene fluoride, etc. In modified PTFE, the content of trace monomer units derived from the above-mentioned trace monomers in relation to the total monomer units is usually in the range of 0.001 to 1.0 mass%. In this specification, "content of trace monomer units in total monomer units (mass %)" means the mass fraction (mass %) of trace monomers derived from the above-mentioned trace monomer units in relation to the total amount of monomers from which the "total monomer units" originate, i.e., the total amount of monomers that constitute the fluorine-containing polymer.

[0074] In terms of heat resistance and electrical properties, PTFE is preferably given a standard specific gravity [SSG] of 2.15 to 2.30, more preferably 2.25 or less, and even more preferably 2.22 or less. While PTFE with an SSG of less than 2.15 does not negate the effects of this disclosure, it is difficult to manufacture and impractical. SSG is a value measured based on the water displacement method in accordance with ASTM D4895-89. When the SSG of PTFE is low, a small amount of additive can increase its biaxial extensional viscosity. When the SSG is high, increasing the amount of additive will achieve the same effect.

[0075] PTFE can be prepared by known methods such as emulsion polymerization and suspension polymerization, but emulsion polymerization is preferred as the polymerization method. If PTFE aggregates are present in the foam molding composition of this disclosure, spark-out may occur frequently during wire coating molding, potentially worsening the defect rate. Therefore, the average primary particle size of PTFE is preferably 50 to 800 nm, and more preferably 50 to 500 nm. The average primary particle diameter of PTFE was determined by measuring the transmittance of 500 nm projection light per unit length for polymer latex diluted with water to a solid content of 0.22 mass%, and based on a calibration curve obtained by measuring the directional diameter in transmission electron microscope images beforehand, comparing it with the above transmittance.

[0076] The content of fluororesin (C) is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.05 parts by mass or more, and also preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 2 parts by mass or less, even more preferably 1 part by mass or less, even more preferably 0.5 parts by mass or less, even more preferably 0.12 parts by mass or less, and particularly preferably 0.1 parts by mass or less, relative to fluororesin (A).

[0077] It is preferable that fluororesin (A) and fluororesin (C) are mixed by co-coagulation. Co-coagulation can be carried out, for example, by mixing an aqueous dispersion containing fluororesin (A) with an aqueous dispersion containing fluororesin (C) and then allowing it to coagulate. In this specification, the process of mixing aqueous polymer dispersions and then allowing them to coagulate is referred to as "co-coagulation."

[0078] Co-coagulation can be carried out using conventional methods as appropriate. The polymer solids concentration in each aqueous polymer dispersion is not particularly limited and can be set appropriately depending on the type and amount of each polymer used, but it is preferably 1 to 70% by mass, and more preferably 3 to 50% by mass. The aqueous medium constituting each polymer aqueous dispersion may contain water, but may also contain a water-soluble organic solvent such as a water-soluble alcohol, or it may not contain such a water-soluble organic solvent. Furthermore, each polymer aqueous dispersion preferably contains conventionally known surfactants, etc., to improve dispersibility, to the extent that it does not impair the moldability of the resulting resin.

[0079] The mixing of the polymer aqueous dispersion can be carried out, for example, using a high-speed stirrer. The mixture obtained by mixing two types of aqueous polymer dispersions is preferably adjusted so that the total solid content concentration of the polymer is 5 to 40% by mass.

[0080] The coagulation method in co-coagulation is not particularly limited; for example, salt coagulation using nitric acid, hydrochloric acid, etc. as a coagulant is one example. Alternatively, methods that do not use a coagulant and instead induce coagulation mechanically, such as by stirring, are also possible.

[0081] After co-coagulation, it is preferable to separate the resin by suction filtration and repeat washing with water and suction filtration until the pH becomes neutral. Subsequently, the recovered resin (wet powder) is preferably dried. This drying is preferably carried out at a temperature of 100 to 240°C for 2 to 48 hours. During this time, methods to accelerate drying, such as reducing the pressure or flowing dry gas, can be used.

[0082] The foam molding compositions of this disclosure may contain resins other than fluororesin (A) and fluororesin (C). Examples of resins other than fluororesin (A) and fluororesin (C) include general-purpose resins such as polyethylene resin, polypropylene resin, vinyl chloride resin, and polystyrene resin; and engineering plastics such as nylon, polycarbonate, polyetheretherketone resin, polyphenylene sulfide resin, polyaryletherketone (PAEK), polyetherketoneketone (PEKK), polyetherketone (PEK), polyetheretherketoneketone (PEEKK), polyethersulfone (PES), liquid crystal polymer (LCP), polysulfone (PSF), amorphous polyarylate (PAR), polyethernitrile (PEN), thermoplastic polyimide (TPI), polyimide (PI), polyetherimide (PEI), and polyamideimide (PAI). One or more of these can be used.

[0083] If the foam molding composition of this disclosure contains resins other than fluororesin (A) and fluororesin (C), it is preferable that these resins are mixed by the cocoating described above.

[0084] The foam molding compositions of this disclosure may further contain boron nitride, to the extent that they do not impair the effects of this disclosure.

[0085] The foam molding compositions of this disclosure may further contain polyatomic anion-containing inorganic salts, to the extent that they do not impair the effects of this disclosure. Examples of the polyatomic anion-containing inorganic salts mentioned above include those disclosed in U.S. Patent No. 4,764,538.

[0086] The foam molding compositions of this disclosure may further contain sulfonic acid, phosphonic acid, or salts thereof, zeolite, etc., to the extent that they do not impair the effects of this disclosure. Organic foaming nucleating agents such as ADCA (azodicarbonamide), DPT (N,N'-dinitropentamethylenetetramine), and OBSH (4,4'-oxybisbenzenesulfonyl hydrazide) may also be used in combination.

[0087] The foam molding compositions of this disclosure may contain conventionally known fillers, to the extent that they do not impair the effects of this disclosure.

[0088] Examples of fillers include graphite, carbon fiber, coke, silica, zinc oxide, magnesium oxide, magnesium sulfate, tin oxide, antimony oxide, calcium carbonate, magnesium carbonate, magnesium hydroxide, glass, talc, mica, aluminum nitride, calcium phosphate, sericite, diatomaceous earth, silicon nitride, fine silica, fumed silica, alumina, zirconia, quartz powder, kaolin, bentonite, and titanium oxide. The shape of the filler is not particularly limited and can be fibrous, needle-shaped, columnar, whisker-shaped, plate-shaped, layered, flaky, balloon-shaped, porous, chopped fiber-shaped, powder-shaped, granular, or bead-shaped. Note that fillers are different from boron nitride.

[0089] The foam molding compositions of this disclosure may further contain other components such as additives. Examples of other components include fillers such as glass fibers, glass powder, asbestos fibers, cellulose fibers, and carbon fibers, as well as reinforcing agents, stabilizers, lubricants, pigments, flame retardants, and other additives.

[0090] If the foam molding composition contains a large amount of fluorine-based low molecular weight compounds, the molten resin may become plasticized during molding, resulting in increased sparking. Therefore, it is preferable that the foam molding composition of this disclosure is substantially free of fluorine-based low molecular weight compounds. Furthermore, "effectively free of fluorinated low-molecular-weight compounds" means that the content of fluorinated low-molecular-weight compounds is 10 ppm by mass or less.

[0091] The fluorinated low molecular weight compounds are not particularly limited, and examples include fluorinated compounds with a molecular weight of 1000 or less. Specifically, examples include perfluoroalkyl acids and perfluorosulfonic acids, and more specifically, C8F 17 CH2CH2-SO3H and its salts, C6F 13 CH2CH2-SO3H and its salts, C8F 17 CH2CH2OH, C6F 13 Examples include CH2CH2OH, and more specifically, {F(CF2)6CH2CH2SO3}2Ba.

[0092] The content of fluorinated low molecular weight compounds can be analyzed by the following method: The sample is pulverized by freeze-milling, the resulting powder is dispersed in methanol, and extracted using sonication at 60°C for 2 hours. The extract is quantified using liquid chromatography-mass spectrometry (LC-MS / MS) and the resulting value is taken as the content.

[0093] The foam molding compositions of this disclosure preferably have a swell of -10 to 20%. More preferably -6% or more, even more preferably -4% or more, and also more preferably 15% or less, even more preferably 8% or less, even more preferably 6% or less, even more preferably 5% or less, and particularly preferably 4% or less. Swell can be measured by the method described in the examples below.

[0094] Swell can be adjusted, for example, by changing the proportion of each resin; increasing the amount of fluororesin (C) tends to increase swell. Furthermore, swell tends to increase with the use of fluororesin (C) with a high molecular weight. In the case of PTFE, the molecular weight is preferably 1 million or more, more preferably 3 million or more, and even more preferably 5 million or more. The molecular weight of PTFE can be determined from its specific gravity. Furthermore, swell can also be adjusted by the screw speed (rotational speed) in kneading (melt extrusion) using a twin-screw extruder, and increasing the rotational speed tends to decrease swell.

[0095] The melt flow rate (MFR) of the foam molding composition of this disclosure is preferably 1 to 100 g / 10 min. More preferably 5 to 70 g / 10 min, even more preferably 10 to 60 g / 10 min, as this suppresses the generation of sparks and increases the foaming rate; even more preferably 15 to 50 g / 10 min, even more preferably 20 to 45 g / 10 min, and particularly preferably 30 to 45 g / 10 min. The above MFR values ​​were measured in accordance with ASTM D-1238, using a die with a diameter of 2.1 mm and a length of 8 mm, under a load of 5 kg and at 372°C.

[0096] To reduce signal loss in communication lines, the dielectric constant of the foam molding composition of this disclosure is preferably 3.0 or less, more preferably 2.5 or less, even more preferably 2.3 or less, and most preferably 2.1 or less. The lower limit is 1.0 or more. Similarly, the dielectric loss tangent is preferably 0.01 or less, more preferably 0.002 or less, even more preferably 0.001 or less, and most preferably 0.0005 or less. The lower limit is 0.0001 or more. The dielectric constant and dielectric loss tangent of the foam molding composition of this disclosure are measured using the resin composition before foam molding by an empty cylinder resonator method at a frequency of 6 GHz.

[0097] The foam molding composition of this disclosure can be suitably used as a foaming composition, and in particular, it can be suitably used as a wire coating composition for forming a coating layer for electric wires.

[0098] The method for manufacturing a foamed molded article according to the present disclosure includes the step of foaming and molding a foamed molding composition according to the present disclosure. Furthermore, the foamed molded article of this disclosure is formed using the foamed molding composition of this disclosure.

[0099] The method for foam molding the foam molding composition of the present disclosure is not particularly limited, and conventionally known methods can be used. For example, one method involves feeding the foam molding composition of the present disclosure into a screw extruder designed for foaming operations and using a continuous gas extrusion method.

[0100] The gas used in the gas extrusion method can be, for example, chlorodifluoromethane, nitrogen, carbon dioxide, or a mixture of the above gases. It may be introduced into the molten resin in the extruder as a pressurized gas, or it may be generated by mixing a chemical blowing agent into the molten resin. The introduced gas dissolves into the molten resin in the extruder.

[0101] The gas dissolved in the resin escapes from the molten material as the pressure of the molten material suddenly drops as it exits the extrusion die. The extruded material is then cooled and solidified, for example, by introducing it into water.

[0102] The foamed molded body of this disclosure has a low dielectric constant, exhibits stable capacitance, and is lightweight, so it can be used as a coating material as described later to obtain a shape with stable dimensions such as wire diameter and thickness.

[0103] The total volume of bubbles in the foamed molded body of this disclosure can be appropriately adjusted according to the application, for example, by adjusting the amount of gas inserted into the extruder, or by selecting the type of gas to be dissolved.

[0104] The foamed molded articles of this disclosure are obtained as molded articles formed according to their intended use during extrusion from the extruder. The molding method is not particularly limited as long as it is heat melt molding, and examples include extrusion foam molding, injection foam molding, and die foam molding.

[0105] The shape of the foamed molded body of this disclosure is not particularly limited and can be in various shapes, such as a covering material for foamed electric wires, a filament-shaped, sheet-shaped, film-shaped, rod-shaped, or pipe-shaped material for wires, etc. The foamed molded body can be used, for example, as an electrical insulating material, a heat insulating material, a sound insulating material, a lightweight structural material such as a floating material, or a cushioning material such as a cushion. Furthermore, the foamed molded body can be used particularly suitably as a covering material for foamed electric wires. The resulting foamed molded article contains a molten and solidified body of the foamed molding composition of this disclosure and bubbles, and it is preferable that the bubbles are uniformly distributed within the molten and solidified body. The bubble size is not limited, but is preferably 60 μm or less, and more preferably 30 μm or less. Furthermore, it is preferable that the bubble size is 0.1 μm or more. The foaming ratio of the foamed molded article is not particularly limited, but is preferably 20% or more. The upper limit of the foaming ratio is not particularly limited, but is, for example, 80%.

[0106] One of the features of the foamed molded article of this disclosure is that its surface is smoother than that of conventional foamed molded articles containing fluororesin. Because of its smooth surface, it can be suitably used in Twinax cables and the like. In this disclosure, the surface of the foamed molded body can be evaluated by scanning it with bare hands and observing the degree of roughness (protrusions) felt on the hand. Alternatively, as described later, the surface can be numerically evaluated by measuring the wire surface with a laser microscope, correcting the obtained image data by specifying the range of the wire using quadratic surface correction for surface shape correction, and then calculating the surface roughness of 500 × 2000 μm. The surface roughness is preferably 9.0 μm or less, more preferably 8.0 μm or less, and even more preferably 7.0 μm or less. The lower limit is not particularly limited, but is usually 1.0 μm or more.

[0107] The bubbles in the foamed molded article of this disclosure may be open or closed, but closed bubbles are preferable. Being closed bubbles has the advantage of strong repulsive force against external pressure, excellent rigidity, shock absorption, and processability, and also prevents moisture from entering the interior. Closed cells can be formed by conventionally known methods in addition to the heat melt molding described above.

[0108] The foamed molded article of this disclosure is in a foamed state that is advantageous for reducing dielectric constant, and can therefore be used as a correlated insulator for, for example, an insulating layer for electric wires, an insulating layer for semiconductor package substrates, an insulating layer for transformers, an insulating layer for circuit boards, an insulating layer for motors, an insulating layer for reactors, an insulating layer for transistors, an insulating layer for printed circuit boards, an insulating layer for semiconductor devices, and an insulating layer for electronic components. In particular, it can be suitably used as an insulating layer (coating layer) for electric wires.

[0109] The method for manufacturing a foamed electric wire according to the present disclosure includes the step of coating a core wire with the foam molding composition according to the present disclosure to obtain a foamed electric wire. By using the foam molding composition according to the present disclosure, a foamed electric wire can be formed having a coating material with fine, uniform bubbles. The step of obtaining the foamed electric wire preferably involves foam molding the foam molding composition according to the present disclosure. Furthermore, the foamed electric wire of this disclosure comprises a core wire and a covering material obtained from the foam molding composition of this disclosure that is applied to the core wire.

[0110] Since the above-mentioned coating material is obtained by coating a core wire with the foam molding composition of this disclosure, it has fine, uniform bubbles. Furthermore, it has a low dielectric constant, exhibits stable capacitance, is lightweight, and allows for the acquisition of a stable shape in terms of wire diameter, thickness, and other dimensions. Furthermore, the coating material has a smooth surface similar to the foamed molded body and exhibits similar physical properties.

[0111] The foamed electric wires of this disclosure can be manufactured in the same manner as conventional methods, except that the foaming composition of this disclosure is coated onto the core wire, for example, by extrusion foaming. Preferred extrusion molding conditions can be appropriately selected depending on the composition of the composition used and the size of the core wire.

[0112] The method for coating a core wire with the foam molding composition of this disclosure is not particularly limited. For example, a method can be used in which a gas soluble in molten fluororesin (molten resin) is used, the foam molding composition of this disclosure is introduced into a screw extruder designed for foaming operations, and a continuous gas injection method is used. The gas used can be the same gas used in the manufacturing method of the foamed molded product.

[0113] The foamed electric wire of this disclosure has a foamed insulating layer in a foamed state that is advantageous for achieving a low dielectric constant, and therefore can suppress signal attenuation compared to conventional electric wires.

[0114] The covering material in the foamed electric wire of this disclosure preferably contains a molten and solidified body and bubbles of the foam molding composition of this disclosure, wherein the bubbles are uniformly distributed within the molten and solidified body. The average bubble diameter is not limited, but is preferably 200 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, even more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. Furthermore, the average bubble diameter is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more. The maximum bubble diameter is not limited, but is preferably 400 μm or less, more preferably 200 μm or less, even more preferably 100 μm or less, even more preferably 80 μm or less, even more preferably 70 μm or less, and particularly preferably 65 μm or less. Furthermore, the maximum bubble diameter is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more. Such a coating structure is obtained as a result of a combination of fluororesin (A) and a specific compound (B) in the foam molding composition of this disclosure. The average bubble diameter was determined by taking images of the cross-section of the coating material using a scanning electron microscope (SEM), calculating the diameter of each bubble through image processing, and averaging the results. The maximum bubble diameter was defined as the largest value among the diameters calculated in the same manner.

[0115] The coating material preferably has a foaming rate of 20% or more. More preferably 30% or more, even more preferably 40% or more, even more preferably 43% or more, and particularly preferably 45% or more. There is no upper limit, but for example, it is 90%. The upper limit of the foaming rate may be 80% or 60%. The foaming ratio is calculated as ((specific gravity of fluororesin - specific gravity of foam) / specific gravity of fluororesin) × 100. The foaming ratio can be adjusted as appropriate according to the application, for example, by adjusting the amount of gas inserted into the extruder or by selecting the type of gas to be dissolved.

[0116] The coating material preferably has fewer than 5 sparks per 3500m. More preferably, it has fewer than 3 sparks, and even more preferably, 1 or fewer. The lower limit is not particularly limited, and may be 0. The number of sparks is a value obtained by measuring it at a voltage of 1500V using a Beta LaserMike Sparktester HFS1220.

[0117] For the core wire material, metal conductor materials such as copper and aluminum, or carbon can be used. Furthermore, even if a single material is used, the surface may be plated with silver or tin. The core wire is preferably 0.02 to 3 mm in diameter. More preferably, the core wire is 0.04 mm or larger, even more preferably 0.05 mm or larger, and particularly preferably 0.1 mm or larger. A core wire diameter of 2 mm or less is even more preferable. The core wire may be a single wire or a stranded wire made by twisting multiple conductors together. The shape of the core wire is not particularly limited; examples include flat wires and rectangular wires.

[0118] Specific examples of core wires include, for example, AWG-46 (solid copper wire with a diameter of 40 micrometers), AWG-42 (solid copper wire with a diameter of 64 micrometers), AWG-36 (solid copper wire with a diameter of 127 micrometers, made by twisting together seven copper wires with a diameter of 51 micrometers, resulting in a total wire size of 153 micrometers), AWG-30 (solid copper wire with a diameter of 254 micrometers, made by twisting together seven copper wires with a diameter of 102 micrometers, resulting in a total wire size of 306 micrometers), AWG-27 ​​(solid copper wire with a diameter of 361 micrometers), AWG-26 (solid copper wire with a diameter of 404 micrometers), AWG-24 (solid copper wire with a diameter of 510 micrometers), and AWG-22 (solid copper wire with a diameter of 635 micrometers).

[0119] The thickness of the covering material is preferably 0.01 to 3.0 mm, and also preferably 2.0 mm or less.

[0120] The surface roughness of the coating material is preferably 9.0 μm or less, more preferably 8.0 μm or less, and even more preferably 7.0 μm or less. The lower limit is not particularly limited, but is usually 1.0 μm or more. The surface roughness is obtained by measuring the surface of the foamed wire using a laser microscope (VK-X1000) manufactured by Keyence Corporation, correcting the obtained image data using quadratic surface correction to specify the range of the wire, and then calculating the surface roughness at 500 × 2000 μm.

[0121] The foamed wires of this disclosure can be used as cables for connecting computers and their peripherals, cables for high-capacity video and audio high-speed communication, cables for connecting servers in data centers, for example, LAN cables, USB cables, Lightning cables, Thunderbolt cables, CATV cables, HDMI® cables, QSFP cables, SPE cables, aerospace cables, underground power transmission cables, submarine power cables, high-voltage cables, superconducting cables, wrapping wires, automotive cables, wire harnesses and electrical components, automotive network cables, robot and factory automation cables, office automation equipment cables, information equipment cables (fiber optic cables, audio cables, etc.), internal wiring for communication base stations, high-current internal wiring (inverters, power conditioners, battery systems, etc.), internal wiring for electronic equipment, small electronic equipment and mobile wiring, movable part wiring, internal wiring for electrical equipment, internal wiring for measuring instruments, power cables (for construction, wind / solar power generation, etc.), control and instrumentation wiring cables, motor cables, etc.

[0122] The foamed electric wires of this disclosure may have a two-layer structure (skin-foam) in which a non-foamed layer is inserted between the core wire and the covering material, a two-layer structure (foam-skin) in which a non-foamed layer is covered on the outer layer, or even a three-layer structure (skin-foam-skin) in which a non-foamed layer is covered on the outer layer of a skin-foam structure. The non-foaming layer is not particularly limited and may be a resin layer made of TFE / HFP copolymer, TFE / PAVE copolymer, TFE / ethylene copolymer, vinylidene fluoride polymer, polyolefin resin such as polyethylene [PE], or polyvinyl chloride [PVC].

[0123] By making the foam molding composition of this disclosure substantially free of fluorine-based low molecular weight compounds, foamed molded articles and foamed electric wires using the foam molding composition of this disclosure can also be made substantially free of fluorine-based low molecular weight compounds. The content of fluorine-based low molecular weight compounds in the foamed molded articles and foamed electric wires of this disclosure can be analyzed by the same method as in the foamed molding compositions of this disclosure.

[0124] The foamed wires of this disclosure are suitably used in communication cables for data centers where high-speed / high-capacity data communication takes place. The communication cable preferably has a structure in which one or more balanced pair cables, each consisting of two foamed wires arranged in parallel or two twisted foamed wires, are arranged, with a shield layer on the outside and a jacket or sheath further outside. That is, the foamed wires of this disclosure preferably further comprises at least one selected from the group consisting of a jacket and a sheath.

[0125] Graphics processing unit (GPU) servers for generative AI, which are expected to see significant growth in the future, generate considerably more heat and consume significantly more power than conventional servers. Therefore, in data centers equipped with GPU servers, cooling components using air cooling or cooling plates is insufficient, and immersion cooling, which involves submerging the entire server in liquid, is being considered.

[0126] Immersion cooling systems mainly include single-phase and two-phase types. Refrigerants include hydrocarbon oils such as mineral oil and ester oil; silicone oils; fluorinated oils; bio-based oils; alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol; glycols such as diethylene glycol, propylene glycol, and hexylene glycol; water such as deionized water and ultrapure water; hydrocarbon solvents such as trichloroethylene and pentane; and fluorinated solvents such as perfluorocarbons and hydrofluoroethers. Specifically, examples include Solvay's Galden® HT90 / 110 / 135 / 150 / 170 / 200, ZV90, SVX, ZT-180; Sanming Hexafluo Chemicals' FTM110 / 135 / 150 / 170 / 200 / 230 / 270; and 3M's Fluorinert® FC-75. Examples of commercially available refrigerants include / 3283 / 40 / 43 / 70 / FX-3300, Novec 7100 / 7200 / 7300 / 7500 / 7600; Chemours Opteon® SF10 / 30 / 33 / 2P50; AGC's Asahiclean® AC 2000 / 6000, Amorea® AS-300; Central Glass's Cerefin® 1233Z / CGS-5E; Daikin Industries' DAISAVE® SS-54 / SS110 / SS49 and Chukyoshin's HFE-65-12. From the standpoint of fire prevention safety, it is preferable to use oil-based or fluorine-based solvents with high boiling points as refrigerants. To prevent corrosion of foamed wires by refrigerants, it is preferable that the foamed wires have a structure in which the outside is composed of a skin layer, such as skin-foam-skin or foam-skin.

[0127] For the jacket and sheath material, for example, polyolefins such as polyvinyl chloride [PVC] and polypropylene [PP]; fluororubber; fluororesin, etc. can be used. As for the fluororesin, those described in fluororesin (A) and (C) above can be used. From the viewpoint of heat resistance and chemical resistance, fluororubber and fluororesin are preferred as the material for the jacket and sheath, fluororesin is more preferred because it is extrudeable and flexible, and perfluororesin such as FEP and PFA is even more preferred. From the viewpoint of moldability, FEP is preferred. FEP may be a binary copolymer or a ternary copolymer, but a ternary copolymer is preferred. Thus, it is also one of the preferred embodiments of this disclosure that the jacket and sheath include at least one selected from the group consisting of fluororubber and fluororesin.

[0128] For the MFR fluororesin used as the material for the jacket and sheath, a concentration of 1 to 40 g / 10 min is preferred, and 1 to 20 g / 10 min is more preferred, from the viewpoint of crack resistance. The MFR of the fluororesin was measured in accordance with ASTM D-1238, using a die with a diameter of 2.1 mm and a length of 8 mm, at 372°C and under a 5 kg load.

[0129] The jacket or sheath may be single-layered or multi-layered. In the case of multi-layered construction, it is preferable that fluororubber or fluororesin is placed on the surface layer from the viewpoint of preventing oil intrusion, and it is more preferable that the thickness of fluororubber or fluororesin is 50 μm to 30 mm from the outside of the surface layer. Also, in the case of multi-layered construction, the layers may or may not be bonded to each other. The inner material may be an olefin resin such as PVC, or a different type of fluororubber or fluororesin from the surface layer, but it is preferable that it be a different type of fluororesin from the surface layer.

[0130] In liquid immersion cooling, it is important that the communication cable is submerged in the liquid, so it is preferable to increase the specific gravity of the covering material (insulator, sheath, jacket) excluding the metal parts. The specific gravity of the covering material excluding the metal parts is preferably greater than 1, and more preferably greater than 1.2.

[0131] The communication cable using the foamed wire of this disclosure offers excellent communication speed and chemical resistance. The communication cable is particularly preferably a balanced pair cable made of foamed wire having a skin-foam-skin or foam-skin structure, with a jacket and / or sheath made of fluororubber and / or fluororesin.

[0132] Although embodiments have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims. [Examples]

[0133] The present disclosure will now be further described with reference to examples, but the present disclosure is not limited to these examples.

[0134] The various properties described herein were measured by the following method.

[0135] (Measurement of unstable terminal cardinal) The pellets were rolled using a hydraulic press to produce a film approximately 0.3 mm thick, and this film was analyzed using an FT-IR Spectrometer 1760X (manufactured by Perkin-Elmer). Obtain the difference spectrum from a standard sample (a sample that has been sufficiently fluorinated until there is no substantial difference in the spectrum), read the absorbance of each peak, and calculate the difference according to the following formula for a sample with 1 × 10 carbon atoms. 6 The number of unstable terminal groups per molecule was calculated. 1 × 10⁻¹⁶ carbon atoms 6 Number of unstable terminal groups per unit = (I × K) / t (I: absorbance, K: correction factor, t: film thickness (unit: mm)) The correction factor (K) for each unstable terminal group is as follows: -COF (1884 cm -1 ) ··· 405 -COOH (1813 cm -1 、1775 cm -1 ) ··· 455 -COOCH3 (1795 cm -1 ) ··· 355 -CONH2 (3438 cm -1 ) ··· 480 -CH2OH (3648 cm -1 ) ··· 2325

[0136] (Measurement of the -CF2H terminal group) Using a nuclear magnetic resonance apparatus AC300 (manufactured by Bruker - Biospin), the measurement temperature was set to the melting point of the fluororesin (A) + 20 °C 19 F - NMR measurement was performed, and it was determined from the integral value of the peak derived from the presence of the -CF2H group and the integral values of other peaks

[0137] (Standard specific gravity (SSG)) Measured based on the water substitution method in accordance with ASTM D4895 - 89

[0138] (Melting point) Using DSC (RDC220 manufactured by Seiko Instruments Inc.), the temperature corresponding to the peak when measured at a heating rate of 10 °C / min was defined as the melting point

[0139] (Thermal decomposition temperature) By TG, the 1% mass loss temperature when heated at 10 °C / min in air was measured

[0140] (Specific surface area) A sample that had been pretreated by vacuum heating and exhausting at 100 °C using Belprep vac - II (manufactured by MicrotracBEL Corp.) was measured for the adsorption isotherm (set relative pressure: adsorption 1.0 × 10 -3 ~ 0.35) by the nitrogen gas adsorption method at liquid nitrogen temperature (77 K), and the specific surface area was determined using the BET method

[0141] (MFR) In accordance with ASTM D-1238, the values ​​were measured using a KAYENESS Melt Indexer Series 4000 (manufactured by Yasuda Seiki Co., Ltd.) with a die measuring 2.1 mm in diameter and 8 mm in length, at 372°C and under a 5 kg load.

[0142] (Swell) Using a melt index tester (e.g., KAYNESS Melt Index Tester [Model 4002]), approximately 2 g of foam molding composition was placed in a 0.376-inch cylinder maintained at 372°C ± 0.5°C. After standing for 5 minutes to allow the temperature to reach equilibrium, the composition was extruded through a die swell measuring orifice with a diameter of 1 mm (error +0.002 mm or less) under a piston load of 5000 g. After the extruded strand cooled to room temperature, its diameter was measured. Here, the strand length was set to 30 ± 5 mm, and the diameter of the strand was taken from the part 5 ± 1 mm above the tip (the part that was extruded first). The diameters of three strands taken at the same time were averaged, and the die swell was calculated using the following formula. Dicewell (%) = [(SD - OD) / OD] × 100 SD: Strand diameter (average of 3 strands) OD: Orifice diameter (1mm)

[0143] (Foamed wire molding) Foamed wire molding was performed by setting the extruder temperature to the specified additive amount, using a Φ0.30 mm copper wire as the core wire, and adjusting the nitrogen gas pressure, nitrogen gas flow rate, extrusion speed (screw rotation speed), and take-up speed so that the outer diameter after coating was 0.80 mm. The extruder conditions are shown in Table 2. The wire extrusion was performed continuously for 1 hour, and for 3500m of material where the molding was stable, the outer diameter, capacitance, number of sparks, surface condition, surface roughness, foaming rate, average bubble diameter, maximum bubble diameter, and number of cells per unit area were analyzed using the following method.

[0144] [Table 1]

[0145] [Table 2]

[0146] (Outer diameter) The outer diameter was measured using a LASER MICRO DIAMETER LDM-303H-XY (manufactured by Takikawa Engineering Co., Ltd.), and the standard deviation was calculated.

[0147] (Capacitance) Capacitance was measured using a CAPAC300 19C (manufactured by Zumbach), and the standard deviation was calculated.

[0148] (Number of sparks) The number of sparks per 3500m was measured using a Beta LaserMike Sparktester HFS1220 at a voltage of 1500V.

[0149] (Surface condition) The surface of the insulated wire was scanned with bare hands, and the degree of resistance (protrusions) felt in the hand was evaluated according to the following criteria. Excellent condition; no snags or issues. Good, but there's a slight catch. It's defective; it's quite rough and catches on things.

[0150] (Surface roughness) The wire surface was measured using a Keyence laser microscope, and the obtained image data was corrected using quadratic surface correction for the wire area. After correction, the surface roughness of 500 × 2000 μm was calculated.

[0151] (Foaming rate) It was calculated as ((Specific gravity of resin composition - Specific gravity of foamed molded product) / Specific gravity of resin composition) × 100.

[0152] (Average bubble diameter, maximum bubble diameter) SEM images of the wire cross-section were taken, and the diameter of each bubble was calculated using image processing. The average bubble diameter was then determined by averaging the calculated diameters. The maximum value among these calculated diameters was defined as the maximum bubble diameter.

[0153] (Number of bubbles per unit) SEM images of the wire cross-section were taken and image processing was performed to reduce the size by 1 mm. 2 The number of bubbles per unit area was calculated.

[0154] (Manufacturing Example 1 (PTFE Homopolymer Dispersion)) As the raw material, an aqueous PTFE dispersion (latex) prepared by the method of Example 1 in International Publication No. 2019-168183 was used. The solid content concentration of the obtained aqueous PTFE dispersion was 21.3% by mass, and the average primary particle size of the polymer was 260 nm.

[0155] A portion of this latex was evaporated to dryness at 200°C for 1 hour to obtain a polymer. The obtained polymer had a standard specific gravity of 2.169, a melting point of 343°C, and an MFR of 0 g / 10 min (unmeasurable).

[0156] (Manufacturing Example 2 (Terrain Polymer Dispersion of TFE / HFP / PPVE)) In accordance with the manufacturing method described in Japanese Patent Publication No. 2010-235667, the reaction scale, reaction pressure, amount of TFE charged, amount of HFP charged, amount of PPVE charged, amount of ammonium persulfate charged, etc., were appropriately adjusted to prepare an aqueous dispersion of TFE / HFP / PPVE copolymer (FEP) with a solid content concentration of 20.5% by mass.

[0157] A portion of the obtained aqueous dispersion (latex) of FEP was evaporated to dryness at 200°C for 1 hour, and the polymer concentration was calculated to be 21.4% by mass based on the obtained solid content. The resulting polymer had an MFR of 38 g / 10 min, a composition ratio (mass%) of TFE / HFP / PPVE = 87.4 / 11.4 / 1.2, a melting point of 262 °C, and a total number of unstable end groups and -CF2H end groups with 1 × 10 carbon atoms. 6 There were 600 pieces per unit.

[0158] (Manufacturing example 3 (PFA pellets)) PFA pellets were obtained by fluorinating pellets obtained by the same method as in Synthesis Example 1 described in International Publication No. 2005 / 052015. The obtained pellets were TFE / PPVE copolymers with a composition ratio (mass%) of TFE / PPVE = 94.9 / 5.1, a melting point of 310°C, a melt flow rate (MFR) of 63 g / 10 min, and a total number of unstable end groups and -CF2H end groups equaling 1 × 10¹⁶ carbon atoms. 6 The result was 0 per unit.

[0159] (Example 1) In the aqueous dispersion of FEP prepared in Production Example 2, water and 60% nitric acid were added and stirred to induce coagulation. After the solid and liquid phases separated, the water was removed. After washing with deionized water, the resulting white powder was dried at 200°C for 60 hours to obtain perfluoropolymer (A) white powder.

[0160] Next, this perfluoropolymer (A) white powder was melted into pellets using a twin-screw extruder (manufactured by Japan Steel Works). This extruder has a shaft diameter of 32 mm, an L / D ratio of 52.5, and consists of a supply section, a plasticizing section, a venting section, and a metering section, starting from the raw material input side. The raw material was supplied at a screw rotation speed of 200 rpm and a rate of 15 kg / hour to obtain resin pellets. These resin pellets were subjected to fluorination treatment by contacting them with 25% by volume fluorine gas diluted with nitrogen gas at a temperature of 200°C for 18 hours. After fluorination treatment, the resin pellets had a total number of unstable end groups and -CF2H end groups with 1 × 10 carbon atoms. 6 The result was 0 per unit.

[0161] Next, sodium 2,2'-methylenebis(4,6-di-t-butylphenyl) phosphate (manufactured by ADEKA Corporation, thermal decomposition temperature: 421℃, SP value: 10.3, specific surface area: 20.8m²) is added to these resin pellets as an additive. 2 The resin composition was obtained by adding 0.5 parts by mass of ( / g, melting point: 400°C or higher) and kneading. The additive was prepared in a mortar and pestle with a specific surface area of ​​31.8 m². 2 It was added after being ground down to [number]g.

[0162] Next, using this resin composition (resin composition for foam molding), foamed wire molding was carried out under the molding conditions shown in Table 3 to obtain foamed wire.

[0163] (Example 2) A resin composition and foamed wire were obtained in the same manner as in Example 1, except that, before adding 40 kg of 60% nitric acid, the PTFE dispersion obtained in Production Example 1 was added under stirring in an amount equivalent to 0.07 parts in solids per 100 parts of the TFE / HFP / PPVE ternary polymer, and the molding conditions were changed.

[0164] (Comparative Example 1) A resin composition and foamed wire were obtained using the same method as in Example 1, except that the additive was not crushed and the molding conditions were changed.

[0165] (Example 3) Additives are mixed in a mortar and pestle. Specific surface area: 27.4 m² 2 A resin composition and foamed wire were obtained using the same method as in Example 1, except that the material was ground down to 1g and the molding conditions were changed.

[0166] (Comparative Example 2) A resin composition and foamed wire were obtained using the same method as in Comparative Example 1, except that the molding conditions were changed.

[0167] (Example 4) A resin composition and foamed wire were obtained in the same manner as in Example 1, except that PFA pellets obtained in Manufacturing Example 3 were used and the molding conditions were changed.

[0168] (Example 5) As an additive, bisphenol phosphate diester Ba salt (2,2'-methylenebis(4,6-di-t-butylphenyl)barium phosphate (thermal decomposition temperature: 421℃, SP value: 10.3, melting point: 400℃ or higher (no peak))) was added in a mortar and pestle to obtain a specific surface area of ​​28.1 m². 2 A resin composition and foamed wire were obtained by the same method as in Example 1, except that the material was crushed to 1 / g and added in 1.0 part by mass, and the molding conditions were changed.

[0169] (Example 6) A resin composition and foamed wire were obtained using the same method as in Example 1, except that the fluorination treatment conditions were changed. The resin pellets after fluorination treatment had a total number of unstable end groups and -CF2H end groups, with 1 × 10 carbon atoms. 6 There were 13 per unit.

[0170] Table 3 shows the analysis results of the resin compositions and foamed wires obtained in the above-described examples and comparative examples. Furthermore, no fluorine-based low-molecular-weight compounds were detected in these resin compositions or foamed wires.

[0171] [Table 3]

[0172] The additives listed in Table 3 are as follows: NA11: Sodium 2,2'-methylenebis(4,6-di-t-butylphenyl) phosphate Bisphenol phosphate diester Barium salt: 2,2'-methylenebis(4,6-di-t-butylphenyl)barium phosphate

[0173] (Reference examples 1~3) For use as jacketing material for electric wires, 120mm diameter, 2mm thick disc-shaped molded products were created by heat pressing using FEP (Daikin Industries' Neoflon FEP NP-120, MFR: 6), PFA (Daikin Industries' Neoflon PFA AP-210, MFR: 14), and PVC (Showa Chemical Industries' flexible polyvinyl chloride compound KVC 22051). Test specimens were then punched into the shape of a dumbbell (No. V) according to ASTM 638. Each test specimen was immersed in various refrigerants at room temperature for one week to remove oil adhering to the surface, and the weight change was measured. A weight change of less than 5% was marked with ○, and a weight change of 5% or more was marked with ×. The results are shown in Table 4.

[0174] [Table 4]

Claims

1. A fluororesin that can be melt-molded (A), The thermal decomposition temperature is 300°C or higher, the solubility parameter (SP value) is 8 to 15, and the specific surface area is 24 to 100 m². ２ A foam molding composition comprising compound (B) in a quantity of / g.

2. The foam molding composition according to claim 1, wherein the compound (B) is a compound comprising at least one substructure selected from the group consisting of an aromatic ring and a phosphate ester group.

3. The foam molding composition according to claim 1 or 2, wherein the compound (B) is a compound containing one or more aromatic rings having 6 to 14 carbon atoms or a salt thereof.

4. The foam molding composition according to claim 1 or 2, wherein the compound (B) is at least one compound selected from the group consisting of phosphate esters and salts thereof, and phosphate ester complex compounds.

5. The foam molding composition according to claim 1 or 2, wherein the compound (B) is an alkali metal salt or an alkaline earth metal salt.

6. The foam molding composition according to claim 1 or 2, wherein the compound (B) is a compound represented by any of the following formulas (1) to (3). 【Chemistry 1】 【Chemistry 2】 【Transformation 3】 (wherein, R １ , R ２ , R ３ , R ４ , R ２１ , R ２２ , R ２３ , R ２４ , R ３１ , R ３２ , R ３３ , R ３４ represents a hydrogen atom, an alkyl group or a cycloalkyl group having 1 to 8 carbon atoms, or an aryl group, an alkylaryl group or an arylalkyl group having 6 to 12 carbon atoms, R ５ , R ６ represents a hydrogen atom or a methyl group, n represents an integer of 1 or 2, m represents an integer of 0 to 2, and X represents a metal having a valence of m + n. )

7. R in the above formulas (1) to (3) １ , R ２ , R ２１ , R ２２ , R ３１ , R ３３ The foam molding composition according to claim 6, wherein is an alkyl group having 1 to 8 carbon atoms.

8. The foam molding composition according to claim 6, wherein X in formulas (1) to (3) is at least one selected from the group consisting of sodium, potassium, rubidium, calcium, and barium.

9. The foam molding composition according to claim 6, wherein the compound (B) is the compound represented by formula (1).

10. The foam molding composition according to claim 9, wherein the compound (B) is at least one selected from the group consisting of 2,2'-methylenebis(4,6-di-t-butylphenyl)sodium phosphate and 2,2'-methylenebis(4,6-di-t-butylphenyl)barium phosphate.

11. The specific surface area of ​​compound (B) is 25 to 50 m². ２ The foam molding composition according to claim 1 or 2, wherein the composition is / g.

12. The foam molding composition according to claim 1 or 2, wherein the fluororesin (A) is at least one selected from the group consisting of tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene / ethylene copolymer.

13. The foam molding composition according to claim 1 or 2, wherein the fluororesin (A) is at least one selected from the group consisting of tetrafluoroethylene / hexafluoropropylene copolymers and tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymers.

14. The foam molding composition according to claim 1 or 2, wherein the fluororesin (A) is a fluororesin that has been treated with fluorination.

15. A foam molding composition according to claim 1 or 2, which substantially does not contain fluorine-based low molecular weight compounds.

16. A foamed molded article obtained from the foaming molded composition according to claim 1 or 2.

17. The foamed molded article according to claim 16, which is substantially free of fluorine-based low molecular weight compounds.

18. A foamed electric wire comprising a core wire and a covering material obtained from the foamed molding composition according to claim 1 or 2, which is applied to the core wire.

19. The foamed electric wire according to claim 18, which is substantially free of fluorine-based low molecular weight compounds.

20. Furthermore, the foamed electric wire according to claim 18 comprises at least one selected from the group consisting of a jacket and a sheath, wherein the at least one selected from the group consisting of a jacket and a sheath includes at least one selected from the group consisting of fluororubber and fluororesin.

21. A method for producing a foamed molded article, comprising the step of foaming and molding the foamed molding composition according to claim 1 or 2.

22. A method for producing a foamed electric wire, comprising the step of coating a core wire with the foam molding composition described in claim 1 or 2 to obtain a foamed electric wire.

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