JP2007092199A - Conductive conjugate fiber having moist heat resistance and conductive fabric having moist heat resistance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a conductive conjugate fiber that has sufficient conductive performance, has slight reduction in conductive performance and strength even after moist heat treatment such as sterilization, etc., and is suitably useful for clothing such as operation uniform for clean room, medical application, interior use such as curtain, etc., and industrial uses. <P>SOLUTION: The conductive conjugate fiber comprises a nonconductive component composed of a polyester-based resin and a conductive component composed of a polyester-based resin containing a conductive particle and exhibits a shape in which at least a part of the conductive component is exposed to the surface of the fiber. Specific amounts of an antimony compound and a phosphorus compound are contained in the conductive conjugate fiber. The conductive conjugate fiber of moist heat resistance has 1×10<SP>6</SP>Ω-1×10<SP>9</SP>Ω/cm electrical resistivity, ≤20 electroconductivity reduction ratio after moist heat treatment (treatment at 121°C for 25 hours) and ≥75% strength retention after moist heat treatment (treatment at 121°C for 25 hours). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a conductive composite fiber composed of a conductive component and a non-conductive component of a polyester-based resin, and there is little decrease in electrical resistance value or strength after wet heat treatment, antistatic work clothes, uniforms, etc. The present invention relates to a heat-and-moisture resistant conductive conjugate fiber that can be suitably used for clothing, interiors such as curtains, and industrial materials.

  Fibers made of hydrophobic polymers such as polyester, polyamide, and polyolefin have many advantages such as mechanical properties, chemical resistance, and weather resistance, and are widely used not only for clothing but also for industrial materials. However, since these fibers generate significant static electricity due to friction, etc., they attract air dust to lower the aesthetics, give an electric shock to the human body, and cause discomfort. Problems such as obstacles and flammable explosions on flammable substances can be caused, and many studies have been conducted to impart conductivity to solve these problems.

  Patent Document 1 describes a core-sheath type composite fiber in which a conductive component containing conductive particles such as conductive carbon black and metal powder is wrapped with a nonconductive polymer. With such a core-sheath type composite fiber, the conductive particles are present only inside the fiber, so troubles during operation are unlikely to occur, and it is possible to obtain good operability. However, since the conductive particles exist only inside the fibers, the conductive performance is insufficient.

  On the other hand, Patent Document 2 describes a core-sheath type conductive composite fiber in which a conductive component containing conductive particles is arranged in a sheath part. Compared with the fiber described in Patent Document 1, such a conductive conjugate fiber was prone to trouble during operation, but the conductivity performance was quite satisfactory.

  In recent years, conductive fibers have been used in clean room work uniforms, medical uniforms, and the like. In such applications, sterilization is repeatedly performed by an autoclave. When the conductive composite fiber is such that the conductive component is arranged in the sheath as described above, there is a problem that the conductive component is cracked by repeating the sterilization treatment, and further the conductive component is missing. There was a decrease in the conductive performance after sterilization, and a decrease in strength due to fiber deterioration.

As described above, in applications where wet heat treatment is performed by an autoclave, cracks in the fiber surface and lack of conductive components are unlikely to occur, and there is little decrease in electrical conductivity and strength due to fiber deterioration, which is sufficient for long-term use. Conductive fibers having conductive performance have not been developed yet.
JP 09-143821 A WO2002 / 075030

  The present invention solves the problems as described above, has sufficient conductive performance, and has little decrease in conductive performance and strength even after wet heat treatment such as sterilization treatment, and is used for clean room and medical work. It is a technical problem to provide a heat-and-moisture resistant conductive composite fiber that can be suitably used for clothing such as uniforms for clothing, interior use such as curtains, and material use.

  The inventors of the present invention have arrived at the present invention as a result of studies to solve the above problems. That is, the gist of the present invention is the following (a) and (b).

(A) A shape composed of a non-conductive component made of a polyester-based resin and a conductive component made of a polyester-based resin containing conductive particles, wherein at least a part of the conductive component is exposed on the fiber surface. The conductive composite fiber is present, wherein the conductive composite fiber contains an antimony compound and a phosphorus compound that satisfy the following formulas (1) to (2) at the same time, and an electrical resistance value of 1 × 10 ⁶ Ω to 1 × 10 ⁹ Ω / cm, decrease in conductivity performance after wet heat treatment (treated at 121 ° C. for 25 hours) is 20 or less, strength retention after wet heat treatment (treated at 121 ° C. for 25 hours) is 75% A heat-and-moisture resistant conductive conjugate fiber characterized by the above.
(1) 0.5 × 10 ⁻⁴ ≦ [Sb] ≦ 3.0 × 10 ⁻⁴
(2) 0.1 × 10 ⁻⁴ ≦ [P] ≦ 20.0 × 10 ⁻⁴
In addition, [Sb] represents the content of the antimony compound, [P] represents the content of the phosphorus compound,
The unit is “mol / acid component mol”.
(B) A moisture-heat resistant conductive conjugate fiber according to (1), wherein the surface leakage resistance is 1 × 10 ⁶ Ω to 1 × 10 ^9. Conductive fabric.

Hereinafter, the present invention will be described in detail.
The conductive composite fiber of the present invention (hereinafter abbreviated as heat and heat resistant conductive composite fiber) is composed of a nonconductive component made of a polyester resin and a conductive component made of a polyester resin containing conductive particles. It is what is done. The composite form of the conductive conjugate fiber of the present invention will be described with reference to the drawings. 1-3 is a schematic diagram showing a cross-sectional shape cut perpendicularly to the longitudinal direction of the fiber of the conductive conjugate fiber of the present invention.

In the conductive conjugate fiber of the present invention, at least a part of the conductive component is exposed on the fiber surface.
As shown in FIG. 1, the conductive component covers the entire fiber surface, that is, the sheath is a conductive component and the core is a non-conductive component in a core-sheath shape, or as shown in FIG. 2. In addition, a shape in which a part of the conductive component is exposed on the fiber surface can be mentioned. The shape of FIG. 2 and FIG. 3 in which a conductive component covers a part of the fiber surface as the shape in which cracking and falling off of the conductive composite fiber are difficult to occur when repeated wet heat treatment is performed. .

  As shown in FIGS. 2A to 2D, a part of the conductive component is exposed on the fiber surface and a part of the fiber surface is covered with the conductive component. A conductive component is present in a non-conductive component, and a part of the conductive component (one side of a substantially triangular shape) is exposed on the fiber surface. The shape of the conductive component is not particularly limited, and may be quadrangular or semicircular.

  FIG. 2 (a) shows that the number of the conductive components is one and the portion exposed on the fiber surface is one, and (b) shows that the number of the conductive components is two and exposed on the fiber surface. There are two places, (c) is three places where the number of conductive components is exposed on the fiber surface, and (d) is four places where the number of conductive components is exposed on the fiber surface. This is an example where there are four locations.

  As for the location exposed to the fiber surface of an electroconductive component, 2-20 locations are preferable, and it is preferable that it is 3-8 locations especially. When the portion exposed on the fiber surface of the conductive component is one place, the portion exposed on the fiber surface is subjected to a wet heat treatment, and when cracks occur or are damaged or missing, In some cases, the conductive performance becomes insufficient, and the original conductive performance cannot be maintained. On the other hand, when the number of the exposed portions of the conductive component on the fiber surface exceeds 20, the exposed portion on the fiber surface increases, and cracks and missing after the wet heat treatment tend to occur. For this reason, the ratio of exposure of the conductive component to the fiber surface is preferably 3/4 or less of the circumference, more preferably 1/2 or less, and more preferably 1/3 to 1/10. When it is less than 1/10 of the circumference, the conductive performance tends to be insufficient, which is not preferable.

  Furthermore, as the shape of the conductive conjugate fiber of the present invention, there are two or more portions exposed on the fiber surface of the conductive component, and the conductive component has a shape communicating with the vicinity of the fiber center portion. preferable. As an example, the ones shown in FIGS. In FIG. 3A, the conductive component is arranged in a straight line through the vicinity of the center of the fiber, and there are two portions exposed on the fiber surface. In (b), the conductive component is arranged in a cross shape through the vicinity of the center of the fiber, and there are four portions exposed on the fiber surface. In (c), the conductive component is arranged in a shape divided into three sides through the vicinity of the center of the fiber, and there are three portions exposed on the fiber surface.

  As described above, the conductive component communicates in the vicinity of the center of the fiber and is exposed at two or more positions on the fiber surface, so that there are a large number of conductive contacts on the fiber surface, and the center between the contacts is present. Since electrical flow is possible in multiple directions by conducting through the section, a fiber having excellent conductivity can be obtained. For this reason, it is preferable that the part exposed to the fiber surface of an electroconductive component shall be 3 or more places especially. However, when the number of exposed portions increases, the exposed portion on the fiber surface increases, and cracks and omissions after sterilization are likely to occur. Further, the ratio of exposure of the conductive component to the fiber surface is preferably 3/4 or less, more preferably 1/2 or less, more preferably 1/3 to 1/1 of the circumference for the same reason as described above. 10.

  In the composite fiber of the present invention, the composite ratio of the nonconductive component and the conductive component is preferably 60 to 90% by mass for the nonconductive component and 40 to 10% by mass for the conductive component. Preferably, the non-conductive component is 70 to 85% by mass and the conductive component is 30 to 15% by mass. When the composite ratio of the conductive component is less than 10% by mass, the conductive performance may not be sufficient. On the other hand, when the composite ratio of the conductive component exceeds 40% by mass, the yarn quality performance such as the strong elongation property is inferior. Or troubles during operation and cracks after sterilization.

The conductive conjugate fiber of the present invention preferably has an electrical resistance value of 1 × 10 ⁶ Ω / cm to 1 × 10 ⁹ Ω / cm, particularly 1 × 10 ⁷ Ω / cm to 1 as the conductive performance. × 10 ⁹ Ω / cm is preferable. When the electrical resistance value of the composite fiber exceeds 1 × 10 ⁹ Ω / cm, the conductive performance becomes insufficient, and the effect of preventing the fabric from being charged becomes small when the resulting fabric is used in a normal environment. On the other hand, if it is attempted to make it less than 1 × 10 ⁶ Ω / cm, it is necessary to contain a large amount of conductive particles in the polymer, which not only adversely affects the physical properties of the fiber but also easily causes troubles during spinning and stretching.

In addition, the electrical resistance value of the conductive conjugate fiber in the present invention is measured as follows according to the AATCC76 method. Conductive conjugate fiber (which may be either multifilament or single yarn) is cut to about 15 cm in the length direction, and 10 samples are collected. Apply keratin cream to the surface of both ends of this sample, connect this surface part to a metal terminal, apply a 50V direct current with a sample measurement length of 10 cm, and measure the current value. Is calculated. The arithmetic average value of the calculated electric resistance values of 10 samples is used.
Electric resistance value = E / (I × L)
E: Voltage (V) I: Measurement current (A) L: Measurement length (cm)

  Next, the performance after the wet heat treatment (treatment at 121 ° C. for 25 hours) of the conductive conjugate fiber of the present invention will be described. The rate of decrease in conductive performance after wet heat treatment is 20 or less, and the strength retention is 75% or more. By adopting the shape of the fiber as described above, and further by using a conductive composite fiber containing a specific amount of an antimony compound and a phosphorus compound, the carboxyl end group concentration can be reduced, and moisture treatment such as sterilization treatment Even if it repeats, it can be set as the fiber which hardly has the fall of the electroconductive performance and the intensity | strength before and behind that.

  Usually, sterilization with high-pressure steam is performed periodically (repeatedly) on surgical clothes, lab coats, food factory uniforms, etc. used in hospitals. Steam treatment at that time, that is, wet heat treatment temperature is 121 ° C. to 135 ° C., and the treatment time is generally about 15 to 5 minutes as the time required for sterilization.

  Since the time required for the wet heat treatment (once) at 121 ° C. is usually about 15 minutes, in the present invention, the conductive performance and strength before and after the treatment are performed by performing a 25 hour treatment corresponding to 100 wet heat treatments. It is used as an index to see the degree of decrease in

First, the rate of decrease in conductive performance after wet heat treatment (treated at 121 ° C. for 25 hours) in the conductive conjugate fiber of the present invention is calculated as follows.
Conductive performance degradation rate = (Y / X)
X: Electrical resistance value of conductive composite fiber before wet heat treatment (Ω / cm)
Y: Electrical resistance value after wet heat treatment of conductive composite fiber (Ω / cm)

  The conductive conjugate fiber of the present invention has a conductive performance reduction rate of 20 or less, and preferably 10 or less. Normally, when the rate of decrease in conductivity performance exceeds 100, the fiber becomes a fiber whose electric resistance value is greatly reduced by wet heat treatment such as sterilization treatment. Even if it has conductivity performance before treatment, it has conductivity performance after treatment. In other words, the durability is inferior and the conductive performance cannot be sufficiently exhibited in each application. By being 20 or less, there is almost no deterioration in the conductive performance, and the durability is extremely excellent.

Furthermore, the strength retention after the moisture treatment in the conductive conjugate fiber of the present invention is determined by grasping the tensile strength of the fiber using a constant speed extension type tester according to the standard time test of tensile strength and elongation rate of JIS-L1013. Measure at an interval of 20 cm. Next, after performing wet heat treatment at 121 ° C. for 25 hours, the strength of the fiber is obtained again by the same method. And it calculates as follows.
Strength retention (%) = (S / M) × 100
S: Tensile strength (cN / dtex) after wet heat treatment of conductive composite fiber
M: Tensile strength of conductive composite fiber before wet heat treatment (cN / dtex)

  The strength retention is preferably 75% or more, more preferably 80% or more. In the fiber obtained by a conventional method, the strength retention is 50% or less. In this case, as the sterilization process is repeated, the decrease in strength increases, and damage is caused by a load caused by wearing, so that the fibers are cut or the quality deteriorates, and at the same time, the conductive performance also decreases. When the strength retention is 75% or more, an excellent performance with almost no decrease in strength can be obtained even after wet heat treatment.

  And the conductive composite fiber of this invention contains the antimony compound and phosphorus compound in the fiber in the quantity which satisfy | fills following formula (1)-(2) simultaneously. As a result, the carboxyl end group concentration is lowered, and the conductive conjugate fiber of the present invention has resistance to moist heat, and has a conductivity reduction rate and strength retention after the wet heat treatment as described above, and The color tone will be excellent.

  Examples of the antimony compound include antimony trioxide, antimony chloride, and antimony acetate. Among them, antimony trioxide is preferably used from the viewpoint of polycondensation catalytic activity, physical properties of the resulting polyester fiber and cost.

  The antimony compound is characterized by a sufficient polycondensation activity, but has the effect of promoting thermal decomposition in the latter stage of the polycondensation reaction. However, when it is added in a large amount, the amount of carboxyl end groups in the polyester increases, and it tends to be a fiber having a reduced wet heat resistance.

  Since it is necessary to reduce the addition amount of the antimony compound within a range where a sufficient polycondensation reaction rate is exhibited, the content of the antimony compound in the polyester fiber satisfies the formula (1).

The content of the antimony compound in the fiber is preferably 0.8 × 10 ⁻⁴ ≦ [Sb] ≦ 2.5 × 10 ⁻⁴ among the range defined by the formula (1). When the value is less than the value determined by the formula (1), the polycondensation activity is not exhibited, and the polycondensation reaction time is prolonged, so that the thermal decomposition reaction proceeds, the carboxyl end group concentration is increased, and the heat and moisture resistance is poor. Become.

  On the other hand, when the content of the antimony compound in the fiber is larger than the value determined by the formula (1), not only the color tone of the polyester is deteriorated but also the thermal decomposition reaction is promoted, so that the carboxyl end group concentration is high. It becomes inferior in heat-and-moisture resistance.

It is important that the polyester fiber of the present invention contains a phosphorus compound in addition to the antimony compound. The content of the phosphorus compound in the fiber needs to satisfy the formula (2), and preferably 0.5 × 10 ⁻⁴ ≦ [P] ≦ 10.0 × 10 ⁻⁴ . As the phosphorus compound, phosphoric acid or its ester (mono-, di- and tri-ester) derived from phosphoric acid or its ester is preferable, and specifically, trimethyl phosphate, triethyl phosphate, triphenyl phosphate. And tris-2-hydroxyethyl phosphate and the like.

  The phosphorus compound not only suppresses deterioration of the color tone of the polyester fiber due to the antimony compound, but also has an effect of suppressing thermal decomposition. When the content of the phosphorus compound in the fiber is less than the value determined by the formula (2), these effects become insufficient, and even if the formula (1) is satisfied, the color tone of the fiber is sufficiently improved, It becomes difficult to improve the wet heat resistance. On the other hand, when the content of the phosphorus compound in the fiber is larger than the value determined by the formula (2), the inside of the polyester system becomes acidic during the polycondensation reaction, thereby forming an ether bond as a side reaction product. Not only is the thermal properties inferior, but the strength also decreases.

  In the conductive conjugate fiber of the present invention, by obtaining appropriate amounts of the antimony compound and the phosphorus compound (amount shown by the formulas (1) to (2)), a fiber having improved moisture and heat resistance can be obtained. It is something that can be done.

Further, in the fiber of the present invention, it is preferable that the contents of the antimony compound and the phosphorus compound satisfy the formula (3) at the same time in order to sufficiently exhibit the above effects.
(3) [P] / [Sb] ≧ 0.2

  As described above, since the phosphorus compound has an effect of suppressing the deterioration of the color tone of the polyester fiber by the antimony compound and the thermal decomposition action, it is preferable to satisfy the formula (3) indicating the ratio with the antimony compound. .

  That is, in the conductive conjugate fiber of the present invention, it is preferable to add an antimony compound and a phosphorus compound during the polycondensation reaction of the polymer to cause the polycondensation reaction. And in this invention, content in the fiber of these compounds shall satisfy Formula (1)-(2) simultaneously, More preferably, Formula (3) shall be satisfied simultaneously.

  Usually, in order to obtain fibers with low carboxyl end group concentration and excellent heat and moisture resistance, it is necessary to carry out melt polymerization and solid phase polymerization in the polyester polycondensation reaction. In addition, by adding a phosphorus compound, a polyester having a low carboxyl end group concentration and excellent moisture and heat resistance can be obtained only by melt polymerization.

  Among them, the carboxyl end group concentration of the conductive conjugate fiber of the present invention is preferably 25 geq / t or less, more preferably 20 geq / t or less, and further preferably 18 geq / t or less. When the carboxyl end group concentration is higher than 25 geq / t, it tends to be inferior in heat-and-moisture resistance.

  Further, the conductive composite fiber of the present invention may contain a compound other than the antimony compound and the phosphorus compound. As these compounds, titanium compounds and cobalt compounds used as polycondensation catalysts are preferable. As the titanium compound, tetra n-butyl titanate, tetra n-propyl titanate, tetraisopropyl titanate, tetraethyl titanate, etc. are used, but tetra n-butyl titanate is preferable from the viewpoint of polycondensation catalytic activity and physical properties of the resulting fiber. . Examples of the cobalt compound include cobalt acetate, cobalt chloride, and cobalt benzoate, and cobalt acetate is preferred from the viewpoint of the physical properties of the resulting fiber.

  The content of the antimony compound and the phosphorus compound in the conductive composite fiber in the present invention is such that after the conductive composite fiber is heated and melted on an aluminum plate, it is formed into a molded body having a flat surface with a compression press machine. This is subjected to quantitative analysis using a line measuring device (Model 3270 manufactured by Rigaku Corporation).

  The carboxyl end group concentration of the conductive composite fiber of the present invention is such that 0.1 g of conductive composite fiber is dissolved in 10 ml of benzyl alcohol, 10 ml of chloroform is added to this solution, and then 1/10 N potassium hydroxide benzyl alcohol is added. It is determined by titration with a solution.

  Next, each component which comprises the electroconductive composite fiber of this invention is demonstrated. First, the conductive component will be described.

  As the polyester resin of the conductive component, polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or the like can be used, and those singly or blended or copolymerized can also be used.

  Among these, since it is excellent in heat and heat resistance, it is preferable to use PET, and PET having an ethylene terephthalate repeating unit of 85 mol% or more is preferable. When the ethylene terephthalate repeating unit is less than 85 mol%, the heat and moisture resistance tends to decrease, such being undesirable.

  And, compared to PBT, PET has a lower kneading property of conductive particles, but by containing a small amount of a specific copolymer component, the content of conductive particles can be increased, and the conductive performance is improved. Therefore, if it is 15 mol% or less, it may contain a copolymer component.

  As such a copolymerization component, isophthalic acid and adipic acid are preferable, and it is preferable to copolymerize either one or both as a copolymerization component. Thereby, the compatibility (surface wettability) between the conductive component and the conductive particles can be improved, the mixing amount of the conductive particles can be increased, and excellent conductive performance can be obtained. Furthermore, the flexibility of the polymer is improved, the spinning and drawing process can be performed smoothly, and the conductive performance can be uniform in the length direction.

  The conductive particles contained in the conductive component include carbon black, metal powder (silver, nickel, copper, iron, tin or alloys thereof), copper sulfide, copper iodide, zinc sulfide, cadmium sulfide, etc. The metal compound of these is mentioned. In addition, a small amount of antimony oxide may be added to tin oxide, or a small amount of aluminum oxide may be added to zinc oxide to form conductive particles.

  Furthermore, it is also possible to use a conductive particle obtained by coating the surface of titanium oxide with tin oxide and mixing and baking antimony oxide. Among these, carbon black (acetylene black, ketjen black, etc.) that is generally used for improving the performance of conductive fibers and hardly inhibits the polymer fluidity as compared with other metal particles.

  The particle size of the conductive particles is not particularly limited, but it is preferable that the average particle size is 1 μm or less. When it exceeds 1 μm, the dispersibility of the conductive particles in the polymer tends to be deteriorated, and the fiber tends to have a deteriorated conductive performance and high elongation property.

  The content of the conductive particles in the conductive component may be appropriately selected depending on the type of conductive particles, conductive performance, particle diameter, particle chain-forming ability, and characteristics of the polymer used. It is preferable to set it as -40 mass%, More preferably, it is 10-30 mass%. If the content is less than 5% by mass, the conductive performance may be insufficient, and if it exceeds 40% by mass, it is difficult to disperse the conductive particles in the polymer.

  Furthermore, the conductive component includes a dispersant, an antioxidant, an ultraviolet absorber, such as waxes, polyalkylene oxides, various surfactants, organic electrolytes, etc., as long as the effects of the present invention are not impaired. Stabilizers, colorants, pigments, fluidity improvers, and other additives can also be added.

  Next, as the polyester resin of the non-conductive component, any polyester polymer that can be melt-spun can be applied. However, as described above, it is preferable to use PET from the viewpoint of moisture and heat resistance. 85 mol% or more of PET is preferred. When the ethylene terephthalate repeating unit is less than 85 mol%, the heat and moisture resistance tends to decrease, such being undesirable.

  In addition, the conductive component polyester-based resin can be dispersed within a range that does not impair the effect, such as waxes, polyalkylene oxides, various surfactants, organic electrolytes, antioxidants, ultraviolet rays. Stabilizers such as absorbents, colorants, pigments, fluidity improvers, and other additives can also be added.

  Such conductive component and non-conductive component are preferably polyesters obtained by polycondensation reaction by adding antimony compound and phosphorus compound as described above, and among them, ethylene terephthalate repeating unit is 85 mol%. An antimony compound and a phosphorus compound are added to the above PET, and the addition amount of these compounds preferably satisfies the above formulas (1) to (2), and further satisfies the formula (3). preferable.

  In the present invention, at least one of the conductive component and the non-conductive component is a polymer containing a specific amount of the antimony compound and the phosphorus compound as described above, or the antimony compound and the phosphorus compound in the conductive composite fiber. The content of can satisfy the above formulas (1) to (2) and further the formula (3). Above all, by making the conductive component a polymer containing a specific amount of antimony compound and phosphorus compound as described above, it becomes difficult for cracks to occur in the conductive component even after repeated wet heat treatment, and the loss or dropping of the conductive particles can be prevented. It becomes difficult to occur, and it can be set as the conductive fiber which has the heat-and-moisture resistance performance which is not found in conventional fibers.

  In addition, even if the conductive component has a core-sheath shape in which the conductive component is a sheath as shown in FIG. 1 or the conductive component is partially exposed to the fiber surface as shown in FIG. Since the conductive component on the fiber surface is easily damaged by wet heat treatment, it is preferable that both the conductive component and the non-conductive component polyester are polyesters containing a specific amount of these compounds.

  Furthermore, the polyester resin of these conductive component and non-conductive component preferably has a carboxyl end group concentration of 25 geq / t or less, particularly 20 geq / t or less, and more preferably 18 geq / t or less.

  When the carboxyl end group concentration of the conductive component and the non-conductive component is higher than 25 geq / t, the carboxyl end group concentration of the conductive composite fiber is also increased, and the heat and moisture resistance tends to be poor.

  The carboxyl end group concentration of the conductive component and the non-conductive component is 1/10 specified after dissolving 0.1 g of the conductive component or non-conductive component in 10 ml of benzyl alcohol and adding 10 ml of chloroform to this solution. It is determined by titration with a potassium hydroxide benzyl alcohol solution.

  Thus, as a method for lowering the carboxyl end group concentration of the conductive component and the non-conductive component, not only a method of adding an antimony compound and a phosphorus compound at the time of polycondensation reaction, but also a method of adding a terminal blocking agent at the time of spinning. And a method of adjusting and changing the polymerization conditions (catalyst amount, temperature, etc.) in solid phase polymerization or melt polymerization.

  Specific examples of the end-capping agent include carbodiimide compounds such as N, N′-bis (2,6-diisopropylphenyl) carbodiimide, and epoxy compounds such as phenyl glycidyl ether.

  That is, in the conductive conjugate fiber of the present invention, either one of the conductive component and the nonconductive component is a polyester having a low carboxyl end group concentration by containing an antimony compound and a phosphorus compound, and the other component is It is good also as polyester which made the carboxyl end group density | concentration low by adding the above terminal blockers or adjusting polymerization conditions.

  The conductive conjugate fiber of the present invention may be a multifilament composed of a plurality of fibers, a monofilament used only with a single yarn, or may be a long fiber or a short fiber.

  In addition, the conductive conjugate fiber of the present invention may be processed yarn that is twisted and mixed with other fibers. Other fibers are not particularly limited, and examples thereof include synthetic fibers such as polyamide, polyester, and polyethylene, regenerated fibers such as rayon, and natural fibers such as cotton, hemp, and wool. Among them, polyester fibers that are the same as conductive composite fibers Is preferable in view of the durability of the wet heat treatment.

  Next, the manufacturing method of the electroconductive composite fiber of this invention is demonstrated. First, as a method for obtaining a conductive component, a method in which conductive particles are added in the polymerization stage of the polymer or a polymer in which conductive particles are added in high concentration in advance are prepared and added to the polymer after polymerization. However, since it is difficult to add conductive particles in the polymerization stage depending on the polymer used, the latter method is preferred. Then, at least one of the non-conductive component and the conductive component contains an antimony compound and a phosphorus compound at the time of the polycondensation reaction of the polyester, and is subjected to melt polymerization to obtain a polyester component having a reduced carboxyl end group concentration.

  The conductive component and the non-conductive component thus obtained are subjected to a treatment such as drying to form a chip, and composite spinning is performed using an ordinary two-component composite melt spinning apparatus. At this time, about the shape and arrangement position of a nonelectroconductive component or a conductive component, it is set as the composite fiber of desired cross-sectional shape by changing a spinneret shape variously. And the electroconductive composite fiber of this invention can be obtained by extending | stretching and heat-processing the obtained thread | yarn.

Next, the conductive fabric of the present invention will be described. The conductive fabric of the present invention is a fabric using at least a part of the conductive conjugate fiber of the present invention as described above, and the surface leakage resistance value indicating the electrical resistance value of the fabric is 1 × 10 ⁶ Ω to 1 It is a thing of * 10 < ⁹ >, and it is preferable that it is especially 1 * 10 < ⁷ > (omega | ohm) -1 * 10 < ⁸ >.

  The proportion of the conductive conjugate fiber of the present invention in the conductive fabric of the present invention is preferably 0.1 to 5.0% by mass. If it is less than 0.1% by mass, it tends to be difficult to impart sufficient electrical conductivity to the fabric. On the other hand, if it exceeds 5.0% by mass, there is no problem in the texture as a fabric, etc., but since the conductive performance is sufficiently imparted, it tends to be disadvantageous in terms of cost.

  Examples of the conductive fabric of the present invention include woven and knitted fabrics, nonwoven fabrics, and various sheets.

  In the case of a woven fabric, it is preferable that the conductive conjugate fiber of the present invention is used for one or both of the warp and the weft, and the conductive conjugate fiber is arranged in the fabric at an interval of 10 mm or less, more preferably 5 mm or less. The woven structure is not particularly limited, and examples thereof include plain weave, twill weave, and entangled weave.

  In the case of a knitted fabric, any of a circular knitting, a weft knitting, and a warp knitting may be used. In the case of a circular knitting or a weft knitting, the conductive conjugate fiber of the present invention is inserted in a border shape at intervals of 10 mm or less, more preferably 5 mm or less. It is preferable to do. Also in the case of warp knitting, it is preferable to insert the conductive conjugate fibers of the present invention in stripes at intervals of 10 mm or less, more preferably 5 mm or less.

  In the case of a non-woven fabric, the conductive conjugate fiber of the present invention is made into a short fiber shape and mixed with other fibers to make a nonwoven fabric, or the conductive conjugate fiber of the present invention is inserted into a nonwoven fabric obtained from other fibers. It is preferable.

The conductive fabric of the present invention has a surface leakage resistance value indicating the electrical resistance value of the fabric of 1 × 10 ⁶ Ω to 1 × 10 ⁹ , and the conductive conjugate fiber of the present invention is used at least in part. Therefore, the surface leakage resistance value after wet heat treatment (treatment at 121 ° C. for 25 hours) is also preferably 1 × 10 ⁶ Ω to 1 × 10 ⁹ , and more preferably 1 × 10 ⁷ Ω to 1 × 10 ⁸ . The surface leakage resistance value is measured in accordance with JIS L 1094 “Reference Surface Leakage Resistance Measurement Method / Kringing Measurement Method”.

When the surface leakage resistance value of the conductive cloth of the present invention is more than 1 × 10 ⁹ Ω / cm, the conductive performance becomes insufficient, when the fabric obtained was used under normal circumstances, to prevent charging of the fabric The effect is poor. On the other hand, if the density is less than 1 × 10 ⁶ Ω / cm, it is necessary to contain a large amount of conductive particles in the polymer in the conductive composite fiber, which not only adversely affects the fiber properties as described above, but also spinning. Troubles easily occur during stretching.

  The conductive conjugate fiber of the present invention has a low carboxyl end group concentration because the content of the antimony compound and phosphorus compound in the fiber is appropriate. In addition, the electrical resistance value is low, it has sufficient conductive performance and strength, and there is little decrease in conductive performance and strength even after wet heat treatment such as sterilization. For this reason, it becomes possible to use suitably in various uses which perform wet heat treatment repeatedly.

  And since the electroconductive cloth of this invention uses the electroconductive composite fiber of this invention for a part, it will have the outstanding heat-and-moisture resistance performance and yarn quality performance. Therefore, the conductive composite fiber and the conductive woven or knitted fabric of the present invention are required to have an antistatic effect and need to be repeatedly subjected to wet heat treatment such as sterilization treatment, such as clothing for clean rooms and medical work uniforms. It can be suitably used for applications, interior applications such as curtains, and material applications.

Next, the present invention will be described specifically by way of examples. In addition, measurement and evaluation of various values in the examples were performed as follows.
1. The electrical resistance value, the conductive performance reduction rate, and the strength retention rate of the conductive conjugate fiber were measured and calculated according to the method described above. In addition, after creating a tubular knitted fabric using the obtained conductive conjugate fiber, a surfactant (Nikko Chemical's Sunmol FL) was used at a concentration of 1 g / l, and scouring treatment was performed at 80 ° C. for 30 minutes. After the treatment, it is treated with hot water at 130 ° C. for 30 minutes. Thereafter, as wet heat treatment, the cylindrical knitted fabric was continuously treated at 121 ° C. for 25 hours using a high-pressure steam sterilizer (HV-50 manufactured by Hirayama Seisakusho). The electrical resistance value of the conductive composite fiber before creating the tubular knitted fabric is taken as the electrical resistance value before the wet heat treatment, and the electrical resistance value of the conductive composite fiber taken out by weaving the tubular knitted fabric after the wet heat treatment is wet. The electrical resistance value after the heat treatment was used.
2. Surface leakage resistance value of conductive fabric (before and after wet heat treatment)
Using the obtained fabric, the surface leakage resistance value was measured according to the method described above. In addition, 1. Using the same high-pressure steam sterilizer, the wet heat treatment was continuously performed at 121 ° C. for 25 hours, and the surface leakage resistance value after the wet heat treatment was measured in the same manner.
3. Content of antimony compound, cobalt compound and phosphorus compound in conductive conjugate fiber Measured by the method described above.
4). Carboxyl end group concentration The carboxyl end group concentration of the conductive component, non-conductive component, and conductive composite fiber was measured by the method described above.

Example 1
A slurry of terephthalic acid and ethylene glycol having a molar ratio of 1 / 1.6 is continuously fed to an esterification reaction vessel in which bis (β-hydroxyethyl) terephthalate and its low polymer (BHET) are present, at a temperature of 250 ° C. The esterification reaction was carried out under the conditions of a pressure of 0.05 kg / cm ² and a residence time of 8 hours, and BHET having an esterification reaction rate of 95% was continuously obtained. 50 kg of this BHET is transferred to a polymerization tank, heated to 270 ° C., and antimony trioxide as a catalyst is 1.0 × 10 ⁻⁴ mol per 1 mol of the acid component constituting the polyester, and cobalt acetate is 1 mol of the acid component constituting the polyester. 0.2 × 10 ⁻⁴ mol per mol, and 0.5 × 10 ⁻⁴ mol of triethyl phosphate as a phosphorus compound was added to 1 mol of the acid component constituting the polyester. Thereafter, the pressure was gradually reduced, and finally a polycondensation reaction (melt polymerization only) was performed at 270 ° C. under a reduced pressure of 0.1 toll for 3.5 hours. Intrinsic viscosity (equal mass mixture of phenol and ethane tetrachloride was used as a solvent, PET (measured at a temperature of 20 ° C.) of 0.64 and a carboxyl end group concentration of 13.0 gq / t (substantially 100 mol% of ethylene terephthalate repeating units) was obtained, and chipped by a conventional method. This was made into the nonelectroconductive component.
Further, PET having an intrinsic viscosity of 0.67 and a carboxyl end group concentration of 30 geq / t (substantially 100 mol% ethylene terephthalate repeating unit) was used as conductive particles, and carbon black having an average particle size of 0.2 μm (in the conductive component). Using a melt kneaded amount of 25% by mass), chips were formed by a conventional method. This was made into the electroconductive component.
Next, using a spinneret designed so that the cross-sectional shape of the single yarn is as shown in FIG. 2 (c), the chips of the conductive component and the non-conductive component are supplied, and the spinning temperature from a normal composite spinning device. Spinning was performed at 295 ° C. so that the composite ratio of conductive components was 20% by mass, and winding was performed at a speed of 3000 m / min while cooling and oiling to obtain 43 dtex / 2f undrawn yarn. Then, the undrawn yarn was drawn 1.53 times through a 90 ° C. heat roller, further heat treated with a heat plate at 190 ° C., and wound up to give 28 dtex having the cross-sectional shape of FIG. / 2 conductive composite fiber was obtained.

Examples 2-3 and Comparative Examples 1-3
Example 1 except that the amounts of antimony compound (antimony trioxide), cobalt compound (cobalt acetate), and phosphorus compound (triethyl phosphate) added during the polycondensation reaction of the nonconductive component were changed as shown in Table 1. Conducting in the same manner, a conductive conjugate fiber was obtained.

Example 4
As the conductive component, PBT having an intrinsic viscosity of 0.67 and a carboxyl end group concentration of 24 geq / t was used instead of PET, and carbon black having an average particle size of 0.2 μm (30% by mass in the conductive component) A conductive conjugate fiber was obtained in the same manner as in Example 1 except that the composition was melt-kneaded and converted into a chip by a conventional method to obtain a conductive component.

Example 5
Conducted in the same manner as in Example 1 except that a spinneret designed so that the cross-sectional shape of the single yarn is as shown in FIG. 3C was used, and a 28 dtex / 2 conductive material having the cross-sectional shape shown in FIG. A functional composite fiber was obtained.

Example 6
As the conductive component, instead of PET, PET (extreme viscosity 0.67, carboxyl end group concentration of 25 geq / t) copolymerized with 5% by mole of isophthalic acid is used as the copolymer component. A conductive conjugate fiber was obtained in the same manner as in Example 3 except that 0.2 μm of carbon black (amount of 30% by mass in the conductive component) was melt-kneaded and converted into a chip by a conventional method to obtain a conductive component. It was.

Comparative Example 4
Example 1 except that a spinneret designed so that the cross-sectional shape of a single yarn is a core-sheath type as shown in FIG. 4 is used, and the conductive component is arranged in the core and the non-conductive component is arranged in the sheath. In the same manner as above, a conductive conjugate fiber was obtained.

  Table 2 shows the measurement results of various values of the conductive conjugate fibers obtained in Examples 1 to 6 and Comparative Examples 1 to 4.

As is clear from Tables 1 and 2, the conductive conjugate fibers of Examples 1 to 6 had low electrical resistance values. Furthermore, the electrical resistance value after wet heat treatment was low, the rate of decrease in conductive performance was low, the conductive performance was excellent, the strength before and after wet heat treatment was high, the strength retention was high, and the yarn quality was also excellent.

  On the other hand, the conductive composite fibers of Comparative Examples 1 to 3 did not contain specific amounts of antimony compound and phosphorus compound in the fiber and had high carboxyl end group concentration, and therefore did not have moisture and heat resistance performance. The electrical resistance value after heat treatment was high, the strength was low, the rate of decrease in conductive performance was high, and the strength retention was low. The conductive conjugate fiber of Comparative Example 4 had a core-sheath shape, and the conductive component was disposed only in the core portion, so that the conductive performance was insufficient.

Example 7
Using an 84 dtex / 36 f multifilament (yarn B) made of ordinary PET and the conductive composite fiber obtained in Example 1, 300 T / M is twisted in the S direction by a twister and the yarn is subjected to twisting. A. A warp yarn was prepared for the yarn A and the yarn B in a ratio of 1:29. As the wefts, the same yarns A and B as the warp yarns were used and woven in a water jet loom to obtain a plain fabric in which the ratio of the yarns A and B was 1:19. The green density at this time was 150 warps / 2.54 cm and 95 wefts / cm.
Further, refining, pre-setting, and dyeing are performed on the above-described plain woven fabric by a known method, and the finishing set is performed so that the yarns A including conductive fibers are arranged one by one at intervals of about 5 mm for both warp and weft. A conductive fabric (100 g / cm ² basis weight) was produced. The finishing density at this time was 165 warps / 2.54 cm and 105 wefts / 2.54 cm.

Comparative Example 5
A conductive fabric was obtained in the same manner as in Example 7, except that the conductive conjugate fiber (obtained in Example 1) used in Example 7 was changed to the conductive conjugate fiber obtained in Comparative Example 1. It was.

Example 8
Using a 28-gauge tricot knitting machine, nylon 6 yarn (fineness 78 dtex / 24f) is used in the front part in the marquezet structure, and five nylon 6 yarns (fineness 44 dtex / 12f) are obtained in the back part in Example 1. One twisted yarn obtained in the same manner as in Example 6 using the conductive composite fiber was used, and the resultant was knitted so as to have a total of six repeated arrangements. Next, refining and dyeing were performed by a known method to obtain an untreated conductive knitted fabric. The green density at this time was 50 courses / 2.54 cm and 30 wales / 2.54 cm.

Comparative Example 6
A conductive knitted fabric was obtained in the same manner as in Example 8, except that the conductive conjugate fiber used in Example 8 (obtained in Example 1) was changed to the conductive conjugate fiber obtained in Comparative Example 1. It was.
Table 3 shows the measurement and evaluation results of the conductive fabrics obtained in Examples 7 to 8 and Comparative Examples 5 to 6.

As apparent from Table 3, since the fabrics of Examples 7 to 8 were obtained by using a part of the conductive conjugate fiber of the present invention, the surface leakage resistance values before and after the wet heat treatment were sufficient. It was of a value and had sufficient electrical conductivity performance and heat-and-moisture resistance performance.

  On the other hand, since the fabrics of Comparative Examples 5 to 6 were partially made of conductive composite fibers having insufficient conductive performance after wet heat treatment, the surface leakage resistance value after wet heat treatment was high and sufficient conductive performance. It did not have.

It is the cross-sectional schematic diagram cut | disconnected perpendicularly | vertically with respect to the longitudinal direction of the fiber which shows one embodiment of the electroconductive composite fiber of this invention. It is the cross-sectional schematic diagram cut | disconnected perpendicularly | vertically with respect to the longitudinal direction of the fiber which shows the other embodiment of the electroconductive composite fiber of this invention. It is the cross-sectional schematic diagram cut | disconnected perpendicularly | vertically with respect to the longitudinal direction of the fiber which shows the other embodiment of the electroconductive composite fiber of this invention. It is the cross-sectional schematic diagram cut | disconnected perpendicularly | vertically with respect to the longitudinal direction of the fiber which shows one embodiment of the conventional electroconductive composite fiber.

Claims (6)

It is composed of a non-conductive component made of a polyester-based resin and a conductive component made of a polyester-based resin containing conductive particles, and has a shape in which at least a part of the conductive component is exposed on the fiber surface. The conductive composite fiber contains an antimony compound and a phosphorus compound that satisfy the following formulas (1) to (2) at the same time, and the electrical resistance value is 1 × 10 ⁶ Ω. ~ 1 × 10 ⁹ Ω / cm, Deterioration rate of electrical conductivity after wet heat treatment (treated at 121 ° C. for 25 hours) is 20 or less, Strength retention after wet heat treatment (treated at 121 ° C. for 25 hours) is 75% or more Moist heat resistant conductive composite fiber characterized by the above.
(1) 0.5 × 10 ⁻⁴ ≦ [Sb] ≦ 3.0 × 10 ⁻⁴
(2) 0.1 × 10 ⁻⁴ ≦ [P] ≦ 20.0 × 10 ⁻⁴
In addition, [Sb] represents the content of the antimony compound, [P] represents the content of the phosphorus compound,
The unit is “mol / acid component mol”. The wet heat resistant conductive conjugate fiber according to claim 1, wherein the carboxyl end group concentration of the conductive conjugate fiber is 25 geq / t or less. The wet heat resistant conductive composite fiber according to claim 1 or 2, wherein at least one of the non-conductive component and the conductive component is polyethylene terephthalate having an ethylene terephthalate repeating unit of 85 mol% or more. The place exposed to the fiber surface of an electroconductive component is 2-20 places, The heat-and-moisture resistant conductive composite fiber in any one of Claims 1-3. The wet and heat resistant conductive conjugate fiber according to any one of claims 1 to 4, wherein the conductive component has two or more exposed portions on the fiber surface and has a shape communicating with the vicinity of the center of the fiber. A fabric using at least a part of the moisture and heat resistant conductive conjugate fiber according to claim 1, wherein the surface leakage resistance value is 1 × 10 ⁶ Ω to 1 × 10 ^9. Moist heat resistant conductive fabric.