JP2012089375A - Synthetic fiber for small-diameter electric wire cord - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic fiber for a small-diameter electric wire cord, which hardly causes breaking due to bending fatigue and the like and an interrupt of electric conduction, and has stable performance.SOLUTION: The synthetic fiber for a small-diameter electric wire cord comprises: a synthetic fiber made of a multifilament; and a treatment agent containing a vapor phase corrosion inhibitor, which is deposited on a surface of the synthetic fiber. In addition, the synthetic fiber is preferably an aromatic polyamide fiber. The treatment agent preferably contains a monobasic acid ester having a molecular weight of 250-600, is an aqueous treatment agent, contains an ether compound prepared by adding 3-9 moles of propylene oxide and/or ethylene oxide to a 8-15C alcohol, and contains an anionic activator. In addition, the vapor phase corrosion inhibitor is preferably a compound having a triazole ring and a benzoate-based compound.

Description

  The present invention relates to a synthetic fiber for small-diameter electric wire cords that requires bending resistance. Furthermore, the present invention relates to a synthetic fiber for a small-diameter wire cord that is suitably used for automobiles, electronic devices, audio devices such as earphones, and telephone cords.

  The structure of thin wire cords represented by earphone cords uses various synthetic fibers as reinforcing fibers around the core, and a copper rod or copper foil is wound around them to insulate vinyl chloride resin, etc. The one covered with the body is common.

  For example, polyester fibers having excellent cost performance are the most common as reinforcing fibers (for example, Patent Document 1). However, such small-diameter electric wire cords are often required to have high-strength characteristics as well as small diameters due to their usage. Recently, aromatic aromatic aramid fibers, polyarylate fibers, and polyolefins are required. Various high-strength fibers such as fibers have been developed and used. Among them, aromatic polyamide fibers have excellent characteristics such as heat resistance, high strength, high modulus, and chemical resistance, and the development of finer fibers has become the mainstream of reinforcing fibers for thin wire cords. (For example, Patent Document 2 and Patent Document 3).

  However, even if such high-strength synthetic fibers are used for reinforcing fibers, depending on the usage situation, a part of the small-diameter wire cord may break due to bending fatigue, etc., resulting in interruption of electrical continuity. There was a current situation that could not be solved sufficiently.

Japanese Utility Model Publication No. 60-69420 Japanese Utility Model Publication No. 2-12113 JP-T-2005-510010

  Therefore, as a result of intensive studies to solve the above problems, the present inventors have found that the subject of the present invention is a synthetic fiber for small-diameter wire cords that has a stable performance with less disconnection due to bending fatigue or the like, and less electrical conduction interruption. It is to provide.

The synthetic fiber for a thin wire cord according to the present invention is characterized in that a treatment agent containing a vaporizable rust preventive agent is attached to the surface of a synthetic fiber made of multifilament.
Further, the synthetic fiber is preferably an aromatic polyamide fiber, and the treatment agent contains a monobasic acid ester having a molecular weight of 250 to 600, an aqueous treatment agent, and a carbon number of 8 to 15. It is preferable to contain an anionic activator that contains an ether compound obtained by adding 3 to 9 moles of propylene oxide and / or ethylene oxide to the alcohol.
The vaporizable rust inhibitor is preferably a compound having a triazole ring or a benzoate compound.

  ADVANTAGE OF THE INVENTION According to this invention, the synthetic fiber for small diameter electric wire cords which has few the disconnection by bending fatigue etc. and interruption | blocking of electrical continuity, and has the stable performance is provided.

  The synthetic fiber for thin wire cords of the present invention needs to be a synthetic fiber composed of multifilaments. By being composed of multifilaments, the stress applied to one single fiber during bending is reduced, and the bending fatigue properties are excellent. The number of multifilaments is preferably 3 to 1000, and particularly preferably 10 to 100. The total fineness of the multifilament is preferably in the range of 10 to 1000 dtex, and more preferably in the range of 20 to 500 dtex, although it depends on the strength and thickness of the finally required thin wire cord. The fineness of the single fiber constituting the multifilament is preferably from 0.1 to 10 dtex, and particularly preferably from 0.5 to 5 dtex. The smaller the single yarn fineness and the greater the number of filaments, the better the bending fatigue property, but the productivity of single yarn breakage and the like decreases, and the bending fatigue property does not necessarily improve.

  As synthetic fibers, general-purpose synthetic fibers such as polyester fibers can be used, and various high-strength synthetic fibers such as aromatic polyamide fibers, polyarylate fibers, and polyolefin fibers are more preferable. Among them, the aromatic polyamide fiber has excellent characteristics such as heat resistance, high strength, high modulus, and chemical resistance, and is optimal as a synthetic fiber for a thin wire cord of the present invention. Aromatic polyamide fibers are also optimal for the purpose of improving bending fatigue, in that fine fibers can be obtained by recent development.

  And in this invention, it is essential that the processing agent containing a vaporizable rust preventive agent has adhered to the surface of the synthetic fiber which consists of the above multifilaments. Here, the vaporizable rust preventive is a metal corrosion inhibitor having a vaporizable property at room temperature. Since the present invention is for an electric wire cord, various vaporizable rust preventives for copper are optimally used. More specifically, examples of the vaporizable rust preventive include heterocyclic compounds, thioureas, and those having a mercapto group. Furthermore, the heterocyclic compound is a compound having a triazole ring, a pyrrole ring, a pyrazole ring, a thiazole ring, an imidazole ring, or the like. In particular, it is preferably a compound having a triazole ring or a benzoate compound.

  Specific examples of the rust inhibitor having a triazole ring include benzotriazole (BTA) and tolyltriazole (TTA). Examples of the benzoate compounds include monoethanolamine benzoate (MEA · BA), dicyclohexylammonium benzoate (DICHA · BA), diisopropylammonium benzoate (DIPA · BA), and the like.

By using these vaporizable rust preventives, it is possible to adsorb rust preventives and form complex compounds on the surface of metal conductors and synthetic fibers, and to form films such as benzotriazole copper salts (Cu · BTA). It is thought that the corrosion suppression mechanism works.
In the present invention, by using these vaporizable rust preventives, it has become possible to effectively rust prevent copper conductors and the like used in small-diameter electric wires.

  The present invention is more effective for synthetic fibers having an equilibrium moisture content of 0.5% by weight or more, and further 1 to 12% by weight. The synthetic fiber of the present invention consists of multifilaments, and there are slight voids and slips between the single yarns, so that bending fatigue resistance is improved. In some cases, rust was caused to the conductor used. Conventionally, not only the conduction is reduced by rust, but also the strength of the conductor is lowered and even the bending fatigue property is lowered. However, the synthetic fiber of the present invention can effectively prevent these phenomena. For example, synthetic fibers having such an equilibrium moisture content include aromatic polyamide fibers, and the application of the present invention is very effective.

  These vaporizable rust preventives used in the present invention can be used by dissolving in a normal fiber oil. The content of the vaporizable rust inhibitor in the oil is preferably 0.1 to 5% by weight, and more preferably 0.3 to 3% by weight. When the content is too small, the rust prevention property for the metal conductor is insufficient, and when it is too large, the dispersibility in the oil agent is poor and the processing to the synthetic fiber surface is difficult, and the smoothness is insufficient. The fluff tends to be induced by rubbing in the manufacturing process.

  As described above, the present invention is particularly effective when the synthetic fiber is a relatively high equilibrium moisture content, for example, an aromatic polyamide fiber. Such an aromatic polyamide fiber is generally abbreviated as an aromatic aramid fiber, and examples thereof include a meta-aramid fiber and a para-aramid fiber. More specifically, meta-aramid fibers are those in which the aromatic ring constituting the main skeleton is bonded to the meta type by an amide bond, but 85 mol% or more of all repeating units of the polymer are metaphenylene isophthalamide units. In particular, polymetaphenylene isophthalamide homopolymer is desirable. As the third component which can be copolymerized at 15 mol% or less, preferably 5 mol% or less of the total repeating units, as the diamine component, for example, paraphenylenediamine, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether , Paraxylylenediamine, biphenylenediamine, 3,3′-dichlorobenzidine, 3,3′-dimethylbenzidine, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 1,5-naphthalenediamine, etc. Aromatic diamines and acid components include aromatic dicarboxylic acids such as terephthalic acid, naphthalene-2,6-dicarboxylic acid and naphthalene-2,7-dicarboxylic acid. In these aromatic diamines and aromatic dicarboxylic acids, part of the hydrogen atoms of the aromatic ring may be substituted with an alkyl group such as a halogen atom or a methyl group. Furthermore, when 20% or more of all terminals of the polymer are blocked with a monovalent diamine such as aniline or a monovalent carboxylic acid component, the strength of the fiber is lowered even when kept at a high temperature for a long time. Since it becomes small, it is preferable. Such a meta-aromatic polyamide can be produced by, for example, a conventionally known method of interfacial polymerization of an aromatic diamine and an aromatic dicarboxylic acid dihalide. The degree of polymerization of the polymer is such that the intrinsic viscosity (IV) measured at 0 ° C. using N-methyl-2-pyrrolidone as a solvent is in the range of 0.8 to 3.0, particularly 1.0 to 2.0. preferable. Such a meta-based polyamide fiber is excellent in heat resistance and is preferable in that strength deterioration does not occur even when an overcurrent flows through the electric wire.

  Next, para-aramid fibers are those in which the aromatic ring constituting the main skeleton is para-bonded by an amide bond, but 85 mol% or more of all repeating units of the polymer are paraphenylene terephthalamide units. Is preferred, and polyparaphenylene terephthalamide (PPTA) is particularly desirable. Although it is a polymer obtained by polycondensation of terephthalic acid and paraphenylenediamine, a copolymer obtained by copolymerizing a small amount of other dicarboxylic acid and diamine can also be used, and the molecular weight of the polymer or copolymer is usually 20,000 to 25,000 are preferable, and PPTA fiber is made by dissolving PPTA in concentrated sulfuric acid, extruding the viscous solution from a spinneret and spinning it in air or water to form a filament. The PPTA fiber before drying and heat treatment at 120 to 500 ° C. is preferably a general PPTA fiber having a crystal size (110 face) of less than 50 mm and more than 50 mm after drying and heat treatment. Used. Such para-based polyamide fibers have high strength, and a sufficient wire cord strength can be obtained with a small amount of fibers, which is particularly effective for reducing the weight and reducing the diameter of the wires.

  In the present invention, it is particularly preferable that the synthetic fiber is an aromatic polyamide fiber as described above, and the treatment agent containing the above-described vaporizable rust preventive agent is attached to the surface of the synthetic fiber for the thin wire cord. It is essential to be. The treatment agent preferably further contains an oil for synthetic fibers.

More specifically, for example, it is preferable that this treating agent is used in combination with a monobasic acid ester, an alkylene oxide addition ether compound, or an anionic activator.
For example, the monobasic acid ester contained in the treating agent is preferably the following component (A).
(A) Monobasic acid ester having a molecular weight of 250 to 600.

  Since the monobasic acid ester having a molecular weight of 250 to 600, which is such component (A), improves the smoothness of the core yarn, the yarn does not loosen, and the copper wire and the copper foil have good seizure. If the smoothness is a little poor, it is easy to induce fluff with the yarn guide by rubbing, and the smoothing agent component used in ordinary synthetic fiber oils has high frictional resistance. Occurrence is suppressed. The monobasic acid ester having a molecular weight of 250 to 600, which is a specific ester component, includes methyl palmitate, methyl stearate, methyl oleate, ethyl stearate, ethyl oleate, isopropyl palmitate, isopropyl stearate, isopropyl oleate, Butyl laurate, butyl stearate, butyl oleate, octyl octanoate, octyl laurate, octyl palmitate, octyl stearate, octyl oleate, isodecyl laurate, isodecyl palmitate, isodecyl stearate, isodecyl Examples thereof include oleate, lauryl laurate, and isotridecyl laurate. When the molecular weight is less than 250, the boiling point is low, and it tends to volatilize at a relatively low temperature. Conversely, if the molecular weight exceeds 600, the viscosity tends to be high and the smoothness tends to be insufficient.

  Furthermore, it is preferable that content of the ester compound which is such (A) component is 40 to 60 weight%. When the content is less than 40% by weight, the smoothness is insufficient, and the yarn guide tends to induce fluff. On the other hand, when it exceeds 60% by weight, particularly when used in an aqueous system, the ratio of the emulsifier tends to be low, the emulsification dispersion is poor, and the stability of the liquid tends to be poor.

Moreover, as an alkylene oxide addition ether compound preferably used for a processing agent, it is preferable that it is the following (B) component.
(B) An ether compound obtained by adding 3 to 9 mol of propylene oxide and / or ethylene oxide to an alcohol having 8 to 15 carbon atoms.

  This (B) component is used in order to make a rust preventive agent adhere uniformly to the synthetic fiber surface. It is particularly useful for aromatic aramid fibers with poor wettability. As the component (B), the alcohol can be used in a linear or branched form, but secondary or tertiary alcohols are preferable, and secondary alcohols are particularly preferable because they can provide more remarkable effects. As such alcohol, 2-ethylhexyl alcohol, 6-dodecyl alcohol, secondary alcohol having 12 to 14 carbon atoms, and the like can be preferably used. Particularly preferred is 2-ethylhexyl alcohol. Further, the total number of moles of propylene oxide and / or ethylene oxide to be added is preferably 3 to 9 moles, more preferably 7 to 9 moles per mole of the alcohol. When the addition amount is out of this range, the wettability of the treatment agent is lowered and the effect of the present invention tends to be reduced.

  The content of the ether compound as the component (B) is preferably 3 to 15% by weight. When the content is too small, the wettability of the oil to the fibers becomes insufficient, and the oil tends to be difficult to adhere to the fibers uniformly. On the other hand, when the adhesion amount is too large, the smoothness becomes insufficient, and there is a tendency that fluff is easily induced by the thread guide by rubbing.

Further, the treating agent preferably contains an anionic activator (hereinafter referred to as component (C)). The anionic activator as the component (C) is mainly used for improving antistatic properties, and is particularly preferably a sulfonate compound, a phosphate ester salt, a higher fatty acid salt or the like. Of course, two or more anionic active agents may be combined. Specific examples of preferable ionic surfactants include the following compounds (a) to (d), which are particularly excellent in antistatic properties, wear resistance, and emulsifying properties.
(A) R ¹ —SO ₃ —X
^{(B) (R 2 -O-)} P (= O) (OX) 2
^{(C) (R 3 -O -} ) (R 4 -O-) P (= O) (OX)
^(D) R 5 -COO-X

Here, R ^{1 to} R ⁵ are a hydrogen atom or an organic group having 4 to 20 carbon atoms. Here, as the organic group, even if it is a hydrocarbon group, a part or all of the hydrocarbon group has a hetero atom such as an ester group, a hydroxyl group, an amide group, a carboxyl group, a halogen atom, or a sulfonic acid group. Or it may be substituted with an element. Preferably it is a C8-C18 hydrocarbon group. X is an alkali metal, an alkaline earth metal, or an amine salt.

The content of these anionic active agents in the oil is preferably 2 to 10% by weight from the viewpoint of improving antistatic properties. If the amount is too small, the antistatic property, wear resistance and emulsifying property tend to be insufficient. On the other hand, if the amount is too large, the rust prevention effect of the rust inhibitor tends to be reduced.
Further, when the synthetic fiber is an aromatic polyamide fiber, it is particularly preferable that the components (A) to (C) are contained in the treatment agent.

  Moreover, when the oil agent containing the vaporizable rust preventive agent and the components (A) to (C) described above is used as a treatment agent, the content of these components is 50 to 80% by weight of the total amount of the oil agent. A range is preferable. The oil component other than those described above is not particularly limited, but may contain, for example, an ester component of a smoothing agent and an emulsifier for making a rust preventive into an aqueous system, a known antioxidant, and the like. Examples of the emulsifier include polyalkylene glycol alkyl ethers, polyalkylene glycol aryl ethers, and alkylene oxide adducts of partially ester polyhydric alcohols. The finishing agent comprising the above components can be attached to the fiber as an emulsion finishing agent without being diluted as it is, or by dispersing 5 to 60% by weight, preferably 5 to 35% by weight, in water. In particular, the treatment agent of the present invention is preferably an aqueous treatment agent that is easy to handle.

  The method for adhering the treatment agent as described above to the surface of the synthetic fiber composed of multifilaments for obtaining the synthetic fiber for thin wire cord of the present invention is not particularly limited, and is usually applied as a finishing agent after stretching. Is possible. Preferably, it is an aqueous emulsion having a concentration of 5 to 20% by weight, and is applied by a conventionally known method such as an oiling roller method or a nozzle method.

  The amount of fiber oil as a treatment agent applied to the synthetic fiber (as a treatment agent active ingredient) is in the range of 0.3 to 5.0% by weight, preferably 1 to 3% by weight, based on the fiber weight. Is preferred. When the applied amount is too large, the oil agent is likely to be scattered when the synthetic fiber is wound, and the periphery of the winder tends to be contaminated. In particular, when the synthetic fiber is a para-aramid fiber, the viscosity of the treatment agent on the fiber surface tends to be high, and the effect of suppressing fluff tends to be insufficient. On the other hand, when the applied amount is too small, the fiber convergence and smoothness are insufficient, and the scum and fluff suppressing effects tend to be insufficient.

  Such a synthetic fiber for a thin wire cord of the present invention not only effectively reinforces an electric wire and has excellent bending fatigue, but also prevents the occurrence of rust on a conductor such as copper existing on the fiber surface, and has high humidity. It is possible to maintain the high bending fatigue property under or for a long time.

  For example, it is possible to make a thin wire by using a synthetic fiber made of this multifilament for the core, brazing a current-carrying body around it, and coating it with a non-conductive resin such as vinyl chloride resin. is there. And this thin diameter electric wire is used for various uses, such as for automobiles, electronic devices, audio devices, and telephone cords, which are often bent and vibrated. It is particularly suitable for earphone cords that require thinness and flexibility.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, all% in an Example shows weight%. Moreover, each evaluation followed the following method.

(1) Amount of oil agent (OPU)
3 g of fiber is dried at 105 ° C. for 2 hours, cooled at room temperature for 30 minutes, and accurately weighed (W ₁ ). Immerse this fiber in 150 g of a 0.5% synthetic detergent solution, treat it with an ultrasonic cleaner for 3 minutes, then wash it with warm water at 40 ° C. for 10 minutes. Air dry overnight, dry at 105 ° C. for 2 hours, cool at room temperature for 30 minutes, and weigh accurately (W ₂ ). OPU was calculated from the following equation.
OPU; (W ₂ −W ₁ ) × 100 / W ₂

(2) Running friction (F / Mμd)
A chrome-plated pin with a diameter of 50 mm is touched with a thread at a winding angle of 180 ° and an initial load (T ₁ ) of 10 g, and is run at a yarn speed of 300 m / min, and the tension (T ₂ ) on the chrome-plated pin exit side is applied. The friction coefficient was calculated from the following equation.
Friction coefficient (f) = 1 / π × ln (T ₂ / T ₁ )

(3) Friction between fiber and fiber at low contact pressure (F / Fμs)
A multifilament fiber (yarn) of about 500 m is wound around a cylinder having a diameter of 5 cm and a length of 30 cm with a spiral angle of plus or minus 15 degrees and a winding tension of about 20 g. Take about 30 cm of the same multifilament fiber (yarn), put it on this cylinder, apply a load of 60 g of initial load (T ₁ ) on _one side, place a U gauge on the opposite side, and place the cylinder at 0.1 m / min. The product was rotated at a peripheral speed, the exit side tension (T ₂ ) was measured, and the friction coefficient was determined by the same method as “(2) Running friction (F / Mμd)”.

(4) Bending fatigue resistance Using multi-filament fibers (220 dtex / 65f) with a bending wear tester (manufactured by TOYOSEIKI, MIT-D type) under the conditions of load R0.38 mm and load gap 0.25 mm. The number of strokes until cutting was determined.

(5) Corrosiveness of copper rods Cut a 2 mm diameter copper wire to 5 cm, wipe the surface with ethanol, then immerse it in a treatment agent (oil) of 90% active ingredient by 2.5 cm. Sealed with a wrap and allowed to stand for 1 week in an environment of 30 ° C. × 85% RH, and the rusted state of the copper wire was observed with the naked eye, and represented in three stages: ○, Δ, and ×.
◯: No rust generation, Δ: Slight rust generation is observed, ×: Rust is much.

(6) Corrosiveness of copper foil A multi-filament fiber (220 dtex / 65f) to which a treatment agent has been attached is covered with a copper foil tape having a width of 0.5 mm and a thickness of 0.1 mm at a core thread of 2050 T / m, and a small diameter bobbin The sample was left to stand for 1 week in an environment of 30 ° C. and 85% RH, and the rust state of the copper foil tape was observed with the naked eye, and represented by three stages: ○, Δ, and ×.
◯: No rust generation, Δ: Slight rust generation is observed, ×: Rust is much.

[Examples 1 to 8, Comparative Example 1]
<Manufacture of multifilament synthetic fibers>
In order to obtain a dope of para-aromatic polyamide, N-methyl 2-pyrrolidone (hereinafter referred to as NMP) having a water content of 100 ppm or less 112.9 parts, paraphenylenediamine 1.506 parts, 3,4′-diaminodiphenyl ether 2.789 A portion was placed at room temperature and dissolved in nitrogen, and then 5.658 parts of terephthalic acid chloride was added with stirring. The reaction was finally carried out at 85 ° C. for 60 minutes to obtain a transparent viscous polymer solution (dope). Next, 9.174 parts of NMP slurry containing 22.5 wt% calcium hydroxide was added to carry out a neutralization reaction. The logarithmic viscosity of the obtained polymer was 3.32.
Using the polymer dope prepared by the above adjustment method, wet spinning was performed by extrusion from a die having a hole diameter of 0.3 mm and a hole number of 65 holes into a coagulation bath of NMP 30 wt%. The distance between the die surface and the coagulation bath was 10 mm. The fiber spun from the die was washed with water, dried, and then stretched 10 times at 520 ° C. to obtain a multifilament of synthetic fiber (para-aromatic polyamide fiber).

<Surface treatment>
The treatment agent (oil agent) shown in Table 1 was applied to the surface of the obtained multifilament synthetic fiber with an oiling roller so that the amount of adhesion was 2.0% by weight with respect to the fiber weight, and then wound around a winder. The obtained synthetic fiber for a thin wire cord had a fineness of 220 dtex and a filament count of 65. The characteristics of the obtained fibers are shown in Tables 1 and 2 together.

The various oil agent components used in the examples and comparative examples in the table are as follows.
BTA: Benzotriazole (vaporizable rust inhibitor)
TTA: Tolyltriazole (vaporizable rust inhibitor)
MEA / BA: Monoethanolamine benzoate (vaporizable rust inhibitor)
DICHA / BA: Dicyclohexylammonium benzoate (vaporizable rust preventive)
A component 1; lauryl laurate A component 2; oleyl laurate B component 1; ethylene oxide 5 mol adduct B component 2 of octyl alcohol B; ethylene oxide 7 mol adduct C component 1 of lauryl alcohol; triethanolol of lauryl phosphate Amine salt C component 2; Dioctylsulfosuccinate sodium salt and other components 1; Ethylene oxide 12 mole adduct of hydrogenated castor oil and other components 2; Sodium acetate salt

Claims (8)

  A synthetic fiber for small-diameter wire cords, characterized in that a treatment agent containing a vaporizable rust inhibitor is adhered to the surface of a synthetic fiber made of multifilament.   The synthetic fiber for a thin wire cord according to claim 1, wherein the synthetic fiber is an aromatic polyamide fiber.   The synthetic fiber for a thin wire cord according to claim 1 or 2, wherein the treatment agent contains a monobasic acid ester having a molecular weight of 250 to 600.   The synthetic fiber for a thin wire cord according to any one of claims 1 to 3, wherein the treatment agent is an aqueous treatment agent.   The thin wire according to any one of claims 1 to 4, wherein the treating agent contains an ether compound obtained by adding 3 to 9 moles of propylene oxide and / or ethylene oxide to an alcohol having 8 to 15 carbon atoms. Synthetic fiber for cords.   The synthetic fiber for a thin wire cord according to any one of claims 1 to 5, wherein the treatment agent contains an anionic activator.   The synthetic fiber for a thin wire cord according to any one of claims 1 to 6, wherein the vaporizable rust inhibitor is a compound having a triazole ring.   The synthetic fiber for a thin wire cord according to any one of claims 1 to 6, wherein the vaporizable rust inhibitor is a benzoate compound.