JPWO2011007575A1 - Resin composition and optical fiber and electric wire using the same - Google Patents

Abstract

The present invention relates to an optical fiber or a resin composition for coating an electric wire that can be cured at low temperature, and the cured product has excellent heat resistance and exhibits excellent flame retardancy without using a flame retardant, more specifically, Following formula (1):

Description

  The present invention relates to an optical fiber and a resin composition for coating an electric wire that have both flame retardancy and heat resistance and are excellent in production efficiency.

  With the recent development of optical communication and increasing demand, optical fibers are used in offices, campuses, and other various information devices. These optical fibers are used in accordance with various usage forms such as single-core, multi-core optical fibers, optical cords, and optical cables. In any of these forms, the optical fibers have various environments. There is a need for heat resistance below and fire resistance in the event of a fire. Also, in electric wire applications, reliability at high temperatures is required as the amount of electric power increases.

  Conventionally, halogen-containing resins represented by vinyl chloride resin have been used as the outer coating of coated optical fiber cores. However, halogen-containing resins generate halogen gas during combustion or cause of generation of dioxins, etc. Therefore, an external coating that can replace the halogen-containing resin is required for environmental measures. Patent Document 1 discloses an optical fiber having a structure in which an outermost outer periphery of an optical fiber having a resin film is coated with a polyamide-based or polyester-based thermoplastic resin to which a flame retardant such as phosphorus or metal hydroxide is added. It is disclosed. Patent Document 2 discloses an electric wire coating resin provided with flame retardancy by adding a specific amount of a triazine compound to a thermoplastic polyamide resin having excellent mechanical properties and heat resistance but insufficient flame retardancy. A composition is disclosed.

  Further, as a heat-resistant optical fiber used in a high-temperature and high-humidity environment recently, Patent Document 3 discloses a first coating layer made of an aromatic polyimide resin that covers the outer periphery of an optical fiber core wire, first An optical fiber having a second coating layer made of a silicon-based resin for covering the coating layer and a third coating layer made of a fluorine-based resin for coating the second coating layer is disclosed.

JP 2001-147353 A JP 2006-152039 A International Publication No. 00/76931

  However, it is necessary to add a large amount of these materials in order to impart high flame retardancy to the coating material using phosphorus-based flame retardants and metal hydrates. As a result, the mechanical strength and other properties are significantly reduced. There is an inevitable problem. In addition, since a coating material using a thermoplastic polyamide-based resin is not crosslinked between polymer molecules, there is a possibility that resistance to an aprotic polar solvent or the like becomes a problem.

  On the other hand, when coating an optical fiber or electric wire using polyimide resin, after applying a polyamic acid varnish, which is a polyimide precursor, onto a quartz fiber or a metal core wire and removing the solvent by heating, an imide ring is formed from the polyamic acid. In order to complete the ring-closure reaction, it is necessary to heat at 200 to 400 ° C. for 3 to 4 hours, and it is very disadvantageous from the viewpoint of productivity to react at such a high temperature for a long time. When the reaction temperature is lowered or the reaction time is shortened in order to increase productivity, the ring closure reaction does not proceed sufficiently, and as a result, polyamic acid remains in the resin, resulting in a decrease in resin physical properties. There is a problem of becoming.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained light produced using a resin composition comprising a polyamide resin having a specific structure, an epoxy resin, a curing accelerator and an organic solvent as a coating material. A fiber-coated wire and a covered electric wire (hereinafter, in the specification of the present invention, “optical fiber-coated wire and covered electric wire” are collectively referred to as “cable”) are a cable using a polyimide resin as a covering material. It can be cured at low temperature and in a short time (intermolecular crosslinking) while having the same heat resistance, and can exhibit flame retardancy without the addition of a flame retardant such as phosphorus or metal hydroxide. As a result, the present invention has been completed.

（式中、ｍ及びｎは、繰り返し単位の平均繰り返し数を表し、ｎ／（ｍ＋ｎ）＞０．０５および０＜ｍ＋ｎ≦２００の関係を満たす。Ａｒ₁は二価の芳香族基を表し、Ａｒ₂はフェノール性水酸基を有する二価の芳香族基を表し、Ａｒ₃は二価の芳香族基を表す。）で表される繰り返し単位を構造中に有するフェノール性水酸基含有芳香族ポリアミド樹脂（Ａ）、エポキシ樹脂（Ｂ）、硬化促進剤（Ｃ）及び有機溶剤（Ｄ）を含有するケーブル用樹脂組成物。
（２）下記式（２）：

（式中Ａｒ₃、ｎおよびｍは、上記式（１）において定義されたものと同義である。ｘは平均置換基数であって１〜４の正数を表す。）で表される繰り返し単位を構造中に有するフェノール性水酸基含有芳香族ポリアミド樹脂（Ａ）、エポキシ樹脂（Ｂ）、硬化促進剤（Ｃ）および有機溶剤（Ｄ）を含有するケーブル用樹脂組成物。
（３）上記（１）または（２）に記載のケーブル用樹脂組成物の硬化物を被覆材として有する石英光ファイバ。
（４）上記（１）または（２）に記載のケーブル用樹脂組成物の硬化物を被覆材として有する電線。That is, the configuration of the present invention is as follows.
(1) The following formula (1):

(In the formula, m and n represent the average number of repeating units and satisfy the relationship of n / (m + n)> 0.05 and 0 <m + n ≦ 200. Ar ₁ represents a divalent aromatic group; Ar ₂ represents a divalent aromatic group having a phenolic hydroxyl group, and Ar ₃ represents a divalent aromatic group.) A phenolic hydroxyl group-containing aromatic polyamide resin having a repeating unit represented by the structure A resin composition for cables containing A), an epoxy resin (B), a curing accelerator (C), and an organic solvent (D).
(2) The following formula (2):

(Wherein Ar ₃ , n and m are as defined in the above formula (1). X is the average number of substituents and represents a positive number of 1 to 4). A resin composition for a cable containing a phenolic hydroxyl group-containing aromatic polyamide resin (A), an epoxy resin (B), a curing accelerator (C), and an organic solvent (D).
(3) A quartz optical fiber having a cured product of the resin composition for cable according to (1) or (2) as a coating material.
(4) An electric wire having a cured product of the resin composition for cables according to (1) or (2) as a covering material.

  The curing temperature of the resin composition for cables of the present invention (hereinafter also simply referred to as “resin composition of the present invention”) is lower than the curing temperature of polyimide, which is 200 to 450 ° C., and is usually 160 to 350 ° C. Because it is within the range, the production efficiency of the cable can be increased, and the cured product has heat resistance equivalent to that of polyimide and can exhibit flame retardancy without containing halogen, phosphorus compound, or metal hydroxide. Therefore, a cable that does not reduce the mechanical strength can be obtained.

Below, the resin composition of this invention is demonstrated in detail. The resin composition of the present invention is also described as a phenolic hydroxyl group-containing aromatic polyamide resin (A) (hereinafter simply referred to as “component (A)”) having a repeating unit represented by the above formula (1) in its structure. ), And the phenolic hydroxyl group-containing aromatic polyamide resin (A) preferably has a repeating unit represented by the above formula (2) in its structure. Here, the component (A) is an aromatic polyamide resin containing a phenolic hydroxyl group, and in the above formulas (1) and (2), a repeating unit represented by —COAr ₁ CO—NHAr ₃ NH— The sequence of the repeating unit represented by COAr ₂ CO—NHAr ₃ NH— is not particularly limited, and is an arbitrary sequence.

Ar ₁ represents a divalent aromatic group in formula (1), Ar ₂ represents a divalent aromatic group having a phenolic hydroxyl group, Ar ₃ represents a divalent aromatic group. In the present specification, the “divalent aromatic group” means a structure in which two hydrogen atoms are removed from an aromatic ring of a compound having at least one aromatic group in the structure, For example, a structure in which one hydrogen atom is removed from each benzene ring located on both sides of oxygen in diphenyl ether is also included in the category of “divalent aromatic group” in the present specification.

Specific examples of Ar ₁ in the formula (1) include phthalic acid, isophthalic acid, terephthalic acid, 4,4′-oxydibenzoic acid, 4,4′-biphenyldicarboxylic acid, and 3,3′-methylene dibenzoic acid. 4,4′-methylenedibenzoic acid, 4,4′-thiodibenzoic acid, 3,3′-carbonyldibenzoic acid, 4,4′-carbonyldibenzoic acid, 4,4′-sulfonyldibenzoic acid 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-naphthalenedicarboxylic acid and other dicarboxylic acids such as residues obtained by removing two carboxyl groups. The residue of isophthalic acid is preferred.
Specific examples of Ar ₂ in formula (1) include dicarboxylic acids having a phenolic hydroxyl group such as 5-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, 2-hydroxyisophthalic acid, 3-hydroxyisophthalic acid, and 2-hydroxyterephthalic acid. Examples include residues obtained by removing two carboxyl groups from acids, and the residue of 5-hydroxyisophthalic acid is preferable.
In addition, x in Formula (2) is the average number of substituents of a hydroxy group, and represents the positive number of 1-4.

Specific examples of Ar ₃ in formula (1) and formula (2) include phenylenediamines such as m-phenylenediamine, p-phenylenediamine and m-tolylenediamine; 4,4′-diaminodiphenyl ether, 3,3 Diaminodiphenyl ethers such as'-dimethyl-4,4'-diaminodiphenyl ether and 3,4'-diaminodiphenyl ether; 4,4'-diaminodiphenyl thioether, 3,3'-dimethyl-4,4'-diaminodiphenyl thioether 3,3′-diethoxy-4,4′-diaminodiphenyl thioether, 3,3′-diaminodiphenyl thioether, 3,3′-dimethoxy-4,4′-diaminodiphenyl thioether, and the like; 4'-diaminobenzophenone and 3,3'-dimethyl- Diaminobenzophenones such as 4,4′-diaminobenzophenone; diaminodiphenyl sulfoxides such as 4,4′-diaminodiphenyl sulfoxide; diaminodiphenyl sulfones such as 4,4′-diaminodiphenylsulfone; benzidine, 3,3′- Bendidines such as dimethylbenzidine and 3,3′-dimethoxybenzidine; diaminobiphenyls such as 3,3′-diaminobiphenyl; xylylene such as p-xylylenediamine, m-xylylenediamine and o-xylylenediamine Examples include residues obtained by removing two amino groups from diamines such as range amines and diaminodiphenylmethanes such as 4,4′-diaminodiphenylmethane, and residues of phenylenediamines, diaminodiphenylmethanes or diaminodiphenyl ethers. Preferably More preferred are residues of diaminodiphenylmethanes or diaminodiphenyl ethers, and particularly preferred are residues of 3,4'-diaminodiphenyl ether or 4,4'-diaminodiphenyl ether from the viewpoint of solvent solubility and flame retardancy of the resulting polymer. .

M and n in Formula (1) and Formula (2) represent the average number of repeating units, and satisfy the relationship of n / (m + n)> 0.05 and 0 <m + n ≦ 200.
When the value of n / (n + m) in the formula (1) and the formula (2) is 0.05 or less, the epoxy resin (B) (hereinafter also simply referred to as “component (B)”) and the component (A ), The cross-linking reaction with the phenolic hydroxyl group does not proceed sufficiently, and the adhesiveness and mechanical strength of the cured product decrease.
Component (A) must have a phenolic hydroxyl group, but when there are too many phenolic hydroxyl groups in component (A), adding an epoxy resin equal to the hydroxyl equivalent will increase the crosslink density of the cured product. If the amount is too large, the flexibility required for the cable covering material may be reduced, and if the epoxy resin is added in an amount less than the hydroxyl equivalent, the heat resistance may be reduced. Therefore, n in the formula (1) and the formula (2) / (N + m) is preferably more than 0.05 and 0.70 or less, more preferably more than 0.05 and 0.50 or less, particularly preferably 0.06 to 0.30, Most preferably, it is 0.07-0.13.
When the value of m + n in the formula (1) and the formula (2) is 0, that is, when the component (A) is not used, the flexibility cannot be exhibited and it is not suitable for the use of the present invention. In addition, when the value of m + n is larger than 200, the solvent solubility is extremely lowered, which causes a problem in the productivity of the component (A) and workability as a varnish. From the balance between the viscosity as a varnish and various physical properties of the cured product, the value of m + n in formula (1) and formula (2) is preferably 2 to 150, more preferably 5 to 100, particularly preferably 10 to 70, Most preferably, it is 20-60.

Component (A) is not particularly limited. For example, polycondensation reaction can be performed by a known method using dicarboxylic acids, dicarboxylic acids having a phenolic hydroxyl group, and diamines exemplified in the description of formula (1). More specifically, as described in JP-A-2006-124545, dicarboxylic acids, dicarboxylic acids having a phenolic hydroxyl group, and diamines exemplified in the description of the above formula (1) Were polymerized in a solvent using an aromatic phosphite such as triphenyl phosphite, and then water was dropped into the reaction solution under heating, resulting in separation of the water and oil layers. It is obtained by standing in stages and removing the aqueous layer.
In the present invention, component (A) is used as a curing agent for component (B).

The component (B) contained in the resin composition of the present invention is not particularly limited as long as it is an epoxy resin having two or more epoxy groups in one molecule. Specifically, it is a novolak type epoxy resin, dicyclopentadienephenol. Condensation type epoxy resin, xylylene skeleton-containing phenol novolak type epoxy resin, biphenyl skeleton containing novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetramethylbiphenol type epoxy resin, etc. are mentioned. A biphenyl skeleton-containing novolac type epoxy resin such as NC-3000 (trade name, manufactured by Nippon Kayaku Co., Ltd.) is preferable because it has high heat resistance and toughness. Two or more of these components (B) can be used in combination.
The amount of component (B) used in the resin composition of the present invention is such that component (B) is based on 1 mole of active hydrogen (hydrogen capable of reacting with an epoxy group such as hydrogen of a phenolic hydroxyl group) possessed by component (A). The amount of the epoxy group is usually 0.01 to 1.0 mol, preferably 0.1 to 1.0 mol.

In the resin composition of the present invention, a curing agent other than the component (A) may be used in combination with the component (A). Specific examples of curing agents that can be used in combination include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, polyamide resin synthesized from linolenic acid and ethylenediamine, phthalic anhydride, triethylene anhydride. Mellitic acid, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic acid anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol novolac resin, trisphenolmethane and these Examples include, but are not limited to, modified products, imidazole, BF ₃ -amine complexes, and guanidine derivatives. When these other curing agents are used in combination, the proportion of the component (A) in the total curing agent is usually 20% by mass or more, and preferably 30% by mass or more. In addition, when using together with another hardening | curing agent, the epoxy group of a component (B) is 0.01-1.0 mol normally with respect to 1 mol of active hydrogen which a component (A) and another hardening | curing agent have, Preferably Is used in an amount of 0.1 to 1.0 mol.

  Specific examples of the curing accelerator (C) (hereinafter also simply referred to as “component (C)”) contained in the resin composition of the present invention include 2-methylimidazole, 2-ethylimidazole and 2-ethyl- Imidazoles such as 4-methylimidazole, tertiary amines such as 2- (dimethylaminomethyl) phenol and 1,8-diaza-bicyclo (5,4,0) undecene-7, and phosphines such as triphenylphosphine And metal compounds such as tin octylate. The usage-amount of the component (C) in the resin composition of this invention is 0.1-5.0 mass parts normally with respect to 100 mass parts of components (A), Preferably it is 1.0-5.0 mass parts. Preferably it is 1.5-5.0 mass parts, Most preferably, it is 2.0-5.0 mass parts.

  Examples of the organic solvent (D) (hereinafter also simply referred to as “component (D)”) contained in the resin composition of the present invention include γ-butyrolactones, N-methylpyrrolidone (NMP), N, N— Amide solvents such as dimethylformamide (DMF), N, N-dimethylacetamide and N, N-dimethylimidazolidinone, sulfones such as tetramethylene sulfone, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, Ether solvents such as propylene glycol monomethyl ether monoacetate and propylene glycol monobutyl ether, and ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone. , Aromatic solvents such as toluene and xylene. The usage-amount of a component (D) is 20-90 mass% normally with respect to the total amount of the resin composition of this invention, Preferably it is 30-80 mass%.

The resin composition of the present invention may contain an inorganic filler as necessary. Specific examples of the inorganic filler that can be used include silica, alumina, talc, and short glass fiber. You may use an inorganic filler in the quantity which occupies 0-90 mass% in the resin composition of this invention.
Furthermore, various compounding agents such as a silane coupling agent, a release agent such as stearic acid, palmitic acid, zinc stearate and calcium stearate, and a pigment can be added to the resin composition of the present invention.

  The resin composition of the present invention can be obtained, for example, by uniformly mixing the components (A), (B), (C) and (D) and optional components added as necessary by a known method. .

Next, the quartz optical fiber or electric wire (hereinafter also referred to as the cable of the present invention) of the present invention will be described in detail. The cable of the present invention is characterized by having a cured product of the above-mentioned resin composition as a coating material, and the cable of the present invention is formed on the surface of a core wire made of a metal such as quartz or copper. The resin composition can be obtained by uniformly applying the resin composition by a conventionally known method, followed by drying and curing by heating. The drying and curing temperature is usually 120 to 350 ° C., preferably 150 to 300 ° C., and the drying and curing time is usually 20 seconds to 3 hours, preferably 30 seconds to 2 hours.
As the crosslinking reaction between the component (A) and the component (B) occurs by heating, the resistance of the resin composition to the solvents (for example, the component (D)) is improved. Accordingly, the reaction conditions may be appropriately determined based on the resistance to the component (D) of the resin composition (cured product) after heating, but in the sense of improving cable production efficiency, a heating furnace used for drying and curing It is more preferable to set the curing temperature as high as possible within the range of the ability, etc., and at the same time to shorten the curing time as much as possible within a range that does not hinder the crosslinking reaction. In the cable of the present invention, when the drying and curing temperature of the above-mentioned resin composition exceeds 250 ° C., resistance to the component (D) is manifested in the drying and curing time of about several tens of seconds to several minutes. Efficiency can be significantly improved.
In the cable of the present invention, the thickness of the resin coating layer (coating material comprising a cured product of the resin composition) is usually 3 to 400 μm, preferably 5 to 350 μm.

  It is also possible to coat the exterior of the quartz core wire with an ultraviolet curable resin, a silicone resin, or the like in order to improve adhesion, and apply the resin composition thereon to dry and cure. Moreover, it is also possible to coat the exterior of a metal core wire such as copper with an insulating film or the like, apply the resin composition thereon, and dry and cure.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

で表される繰り返し単位を構造中に有する成分（Ａ）３３２質量部を得た。この成分（Ａ）中に含まれる元素量を蛍光Ｘ線測定装置で定量したところ、全リン量は１５０ｐｐｍ、全塩素量は２０ｐｐｍであった。また、得られた成分（Ａ）の固有粘度は０．５２ｄｌ／ｇ（ジメチルアセトアミド溶液、３０℃）であり、ゲルパーミエイションクロマトグラフィーの測定結果を元にポリスチレン換算で求めた数平均分子量、及び合成反応に用いた各成分のモル比から算出した式（３）中のｍの値は約３６であり、ｎの値は約４であった。Example 1
A flask equipped with a thermometer, a condenser tube, a fractionator tube, and a stirrer was purged with nitrogen while 18.2 parts by mass of 5-hydroxyisophthalic acid, 149.4 parts by mass of isophthalic acid, 3,4'-diaminodiphenyl ether 204 parts by mass, 12.8 parts by mass of lithium chloride, 1360 parts by mass of N-methylpyrrolidone, and 272 parts by mass of pyridine were added and dissolved by stirring. By making it react, the reaction liquid of the component (A) was obtained. While stirring this reaction solution, 1300 parts by mass of water was added dropwise at 90 ° C. over 3 hours, further stirred at 90 ° C. for 1 hour, cooled to 60 ° C., and allowed to stand for 30 minutes. Since the upper layer was separated into an aqueous layer and the lower layer was separated into an oil layer (resin layer), the upper layer was removed by decantation. The amount of waste water was 1200 parts by mass. The oil layer (resin layer) was diluted by adding 1200 parts by mass of N, N-dimethylformamide. The water washing step by water addition, layer separation, decantation and solvent addition was further repeated 4 times to wash the component (A). The component (A) solution thus obtained is sprayed into 6000 parts by mass of stirred water using a two-fluid nozzle, and the precipitated fine powder of component (A) having a particle size of 5 to 50 μm is filtered. Separated. The obtained wet cake of the precipitate was dispersed in 3200 parts by mass of methanol and refluxed for 2 hours with stirring. Next, methanol was filtered off, and the precipitate collected by filtration was washed with 3200 parts by mass of water and then dried to obtain the following formula (3):

332 parts by mass of the component (A) having a repeating unit represented by When the amount of elements contained in this component (A) was quantified with a fluorescent X-ray measuring apparatus, the total phosphorus content was 150 ppm and the total chlorine content was 20 ppm. Moreover, the intrinsic viscosity of the obtained component (A) is 0.52 dl / g (dimethylacetamide solution, 30 ° C.), and the number average molecular weight determined in terms of polystyrene based on the measurement result of gel permeation chromatography, The value of m in the formula (3) calculated from the molar ratio of each component used in the synthesis reaction was about 36, and the value of n was about 4.

  Thus, with respect to 100 parts by mass of the component (A) obtained, 10 parts by mass of NC-3000 (trade name, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 275 g / eq.) As the component (B) The resin composition of the present invention is obtained by adding 2 parts by mass of 2-phenyl-4,5-dihydroxymethylimidazole (2PHZ) as C) and 260 parts by mass of dimethylformamide as component (D) and mixing them uniformly. It was.

  The resin composition of the present invention thus obtained was applied on a quartz glass having a thickness of 1.2 mm so as to have a thickness of 15 μm after drying using a roll coater, and then at 180 ° C. for 1 hour. The solvent was removed and cured under the following heating conditions. A notch with a width of 1 cm is made in the cured film on the obtained quartz glass, and one end thereof is peeled off from the quartz glass, and 90 ° using a Tensilon tester (manufactured by Shimadzu Corporation, Autograph AGS-J 500N). The peel strength was measured at an angle of 1.5N, which was a sufficiently high value of 1.5N. In addition, DMF was dropped on the surface of the obtained cured film and allowed to stand for 5 minutes, and the appearance after wiping off DMF was observed. However, no abnormality was observed, and it was cured (cross-linked) to the extent that resistance to the solvent could be expressed. I confirmed that

  In addition, the resin composition of the present invention thus obtained was applied onto a 25 μm thick copper foil using a roll coater so that the thickness after drying was 40 μm, and at 300 ° C. for 1 minute. The solvent was removed and cured under the following heating conditions. A notch with a width of 1 cm is made in the cured film on the obtained copper foil, one end thereof is peeled off from the copper foil, and 90 ° using a Tensilon tester (manufactured by Shimadzu Corporation, Autograph AGS-J 500N). The peel strength was measured at an angle of 1.9 N, which was a sufficiently high value. In addition, DMF was dropped on the surface of the obtained cured film and allowed to stand for 5 minutes, and the appearance after wiping off DMF was observed. However, no abnormality was observed, and it was cured (cross-linked) to the extent that resistance to the solvent could be expressed. I confirmed that

  Further, the above resin composition of the present invention was applied onto a PET film so that the thickness after drying was 50 μm, and the solvent was removed and cured under heating conditions at 180 ° C. for 1 hour. The sheet-like sample was obtained by removing. The obtained sample did not crack even when bent, and had sufficient flexibility. When the flame retardant test according to UL94-VTM was done to this hardened | cured material, V-0 which is a flame-retardant parameter | index was cleared. Moreover, it was 254 degreeC when the glass transition temperature of this sample was measured by DMA.

  From the above, the resin composition of the present invention exhibits high adhesion to quartz glass and copper even when cured at a low temperature of 200 ° C. or lower, or at 300 ° C. for a short time of 1 minute, It can be seen that the cured product exhibits high heat resistance comparable to that of a cured polyimide resin, and has flame retardancy without adding additives such as halogen, phosphorus, and metal oxide. From these results, the resin composition of the present invention is extremely useful for cable applications.

The resin composition for a cable of the present invention can be cured at a temperature lower than that of a general polyimide resin or in a short time when the temperature is high, so that the production efficiency of the cable can be increased. In addition, the cured product of the resin composition for cable of the present invention has the same heat resistance as the cured product of the polyimide resin, and exhibits flame retardancy without containing halogen, a phosphorus compound, or a metal hydroxide. When used as a cable covering material, a cable that maintains mechanical strength can be obtained.

Claims (4)

Following formula (1):

(In the formula, m and n represent the average number of repeating units and satisfy the relationship of n / (m + n)> 0.05 and 0 <m + n ≦ 200. Ar ₁ represents a divalent aromatic group; Ar ₂ represents a divalent aromatic group having a phenolic hydroxyl group, and Ar ₃ represents a divalent aromatic group.) A phenolic hydroxyl group-containing aromatic polyamide resin having a repeating unit represented by the structure A resin composition for cables containing A), an epoxy resin (B), a curing accelerator (C), and an organic solvent (D). Following formula (2):

(Wherein Ar ₃ , n and m are as defined in the above formula (1). X is the average number of substituents and represents a positive number of 1 to 4). A resin composition for a cable containing a phenolic hydroxyl group-containing aromatic polyamide resin (A), an epoxy resin (B), a curing accelerator (C), and an organic solvent (D).   A quartz optical fiber having a cured product of the resin composition for a cable according to claim 1 or 2 as a coating material.   An electric wire having a cured product of the resin composition for a cable according to claim 1 or 2 as a covering material.