JPS63270811A - Electrically conductive composite fiber - Google Patents

Abstract

PURPOSE:To obtain the titled fiber having high whiteness and excellent spinnability and fiber properties, by joining a fiber-forming polymer with a polymer containing a specific amount of inorganic particles and potassium titanate short fibers surface-coated with an electrically conductive metallic compound. CONSTITUTION:The objective fiber suitable for general clothes, antistatic cloth ing, etc., is produced by joining (A) one or more kinds of polymers such as polyethylene terephthalate and nylon containing (i) potassium titanate short fibers surface-coated with an electrically conductive metallic compound consisting of preferably tin oxide, zinc oxide, indium oxide, cuprous iodide or one or more kinds of metallic compounds composed mainly of the above compounds and (ii) inorganic particles which are preferably white inorganic particles having diameter of 0.01-2mu with (B) a fiber-forming polymer in the form of core-sheath structure, etc. The amount of the component (ii) is >=5pts.wt. based on 100pts.wt. of the component A.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a white conductive composite fiber.

(Prior art) In recent years, in order to solve the problem that conductive fibers containing carbon fibers and carbon black particles are black or gray, which limits their uses, research has been conducted to develop a method that maintains a good color tone even after dyeing with white. The development of conductive fibers with These are, instead of the black conductive material mentioned in 1.
It uses a conductive material that is white or close to white in color. A typical method is JP-A-55-107
JP-A-58-223208 discloses a method of treating iodine-absorbed polyester or polyamide fibers with an aqueous solution of a cuprous compound to incorporate cuprous iodide into the fibers, as disclosed in Japanese Patent Application Laid-open No. 58-223208. , No. 59-47474, Japanese Patent Publication No. 62-11088, and the like, which involve melt-kneading titanium oxide whose surface is coated with tin oxide and a resin such as polyamide. However, in the method using such white conductive particles,
In order to obtain sufficient electrical conductivity, it is necessary to introduce a large amount of particles, resulting in a disadvantage that the spinnability of the fiber and the physical properties of the fiber deteriorate. In order to overcome this drawback, a method is known in which short glass fibers whose surfaces are coated with a white conductive metal compound are used, as disclosed in Japanese Unexamined Patent Publication No. 59-94818. This method attempts to obtain high electrical conductivity, good spinning properties, and fiber properties by introducing a smaller amount of electrically conductive material than in the case of particulate electrically conductive material. However, in reality, the short glass fibers break during the process of repeating melt-kneading to obtain a homogeneous mixture, resulting in a problem in that the desired effect cannot be obtained sufficiently. On the other hand, there is potassium titanate short fiber whose surface is coated with stannic oxide, which is disclosed in Japanese Patent Publication No. 61-26933 as a fibrous white conductive substance, and compositions and molded products containing it are molded. It is shown in JP-A-60-9005 that it has excellent properties and stability. However, when this is applied to fibers, the potassium titanate short fibers become oriented during the spinning process such as spinning and drawing, and as a result, the probability of contact between the potassium titanate short fibers decreases, so the conductive effect is not sufficient. There was a problem that I couldn't get it.

(Problems to be Solved by the Invention) The present invention prevents the problems of the prior art, that is, the deterioration of spinnability and the deterioration of fiber physical properties due to the addition of particulate conductive substances, and, on the other hand, prevents the problems of the prior art. The purpose is to provide an excellent white conductive conjugate fiber that does not cause a decrease in conductivity during the manufacturing process or during long-term use due to addition.

Ta. That is, the present invention provides at least one type of polymer [A] containing potassium titanate short fibers whose surfaces are coated with a conductive metal compound (hereinafter referred to as "conductive potassium titanate short fibers") and inorganic particles. , a conductive composite fiber bonded with a fiber-forming polymer [B], wherein the amount of inorganic particles contained in the polymer [A] is 5 parts by weight or more based on 1100 parts by weight of the polymer [A]. It is a conductive composite fiber characterized by the following.

The conductive metal compound used in the present invention includes:
Examples include stannic oxide, zinc oxide, indium oxide, and cuprous iodide, but stannic oxide is preferred from the viewpoint of color tone, stability, and ease of production, and those doped with a small amount of antimony are preferred. preferable. The conductive potassium titanate short fibers preferably have a fiber diameter of 0.01 to 2μ and a fiber length of 1 to 500μ; 5μ and fiber length in the range of 5 to 20μ is preferred. Further, in order to improve dispersibility, the surface of the short fibers may be surface-treated with a silicone-based coupling agent, a titanate-based coupling agent, or the like.

Examples of the inorganic particles used in the present invention include white particles used in ordinary fibers such as titanium oxide, zirconium oxide, magnesium oxide, silica, and alumina.In order to further improve the conductive effect, tin oxide,
Zinc oxide, indium oxide, cuprous iodide, and white conductive particles containing these as main components, or tin oxide, zinc oxide, indium oxide, cuprous iodide, and one or more of these as main components. titanium oxide, zirconium oxide, magnesium oxide, coated with white conductive material,
Inorganic particles such as silica and alumina can also be used.

The size of these particles is preferably 0.01 to 2 μm in diameter from the viewpoint of processability and ease of manufacture, but from the viewpoint of spinning properties and conductivity, the diameter is 0.1 to 0.5 μm. It is more preferable to use a range of . In addition, from the viewpoint of color tone, it is preferable that the inorganic particles used have high white discoloration. In order to further improve dispersibility, the surfaces of the particles may be treated with a silicone coupling agent, a titanate coupling agent, or the like.

The polymers used for polymers [A] and [B] in the present invention are not particularly limited, but for example, polyethylene terephthalate, polybutylene terephthalate, nylon 6,
Examples include nylon 66, polyethylene, polyethylene glycol, polypropylene glycol, and the like. The combination of polymers [A and B] is not particularly limited, but in order to avoid peeling at the interface between the two components, a combination that has good affinity between the two is preferred, and furthermore, they are the same components. is most preferable. The joining form of polymers [A] and [B] is not particularly limited, but side-by-side carving, which is the joining form of ordinary composite fibers,
Although it can take a core-sheath form, a sea-island form, etc., from the point of view of color and 74, the polymer [A] containing conductive potassium titanate short fibers and inorganic particles is different from the polymer [B ] Most preferred is a core-sheath configuration covered and concealed by. At this time, by incorporating white particles such as titanium oxide into the polymer B that forms the sheath, it is possible to enhance the effect of hiding the core and further increase the whiteness of the composite fiber. From the viewpoint of the conductivity of the composite fiber, it is preferable that the polymer [B] forming the sheath portion includes a hydrophilic polymer such as polyethylene glycol dispersed in stripes in the fiber axis direction. Here, at the bonding interface of polymers [A] and [B],
An adhesive layer may be present to suppress peeling of both components. In order for the composite fiber to have good spinning properties and fiber physical properties, the composite ratio of polymers [A] and [B] should be the cross-sectional area ratio of [A]:[B]=95 to 30:
70 is preferable. In order for the composite fiber to have sufficient conductivity and good processability, the content of the conductive potassium titanate short fibers in the polymer [A]
When 100 parts by weight, the amount is 5 to 65 parts by weight, preferably 20 to 40 parts by weight. Further, the content of inorganic particles in the polymer [A] is 5 to 55 parts by weight, preferably 10 to 3 parts by weight when the polymer [A] is 1100 parts by weight.
It is 0 parts by weight. However, the total content of conductive potassium titanate short fibers and inorganic particles in polymer [A] is
In order for composite fibers to have good processability, polymer [A]
When 100 parts by weight, the amount is 70 parts by weight or less, preferably 50 parts by weight or less. Furthermore, a surfactant or the like may be added for the purpose of improving the dispersibility of the conductive potassium titanate short fibers and conductive particles in the polymer [A].

The composite fibers of the present invention can be produced by conventionally known methods. For example, mixing the conductive potassium titanate short fibers and inorganic particles with the polymer component [A] is carried out in a polymer melt. If conductive potassium titanate short fibers and inorganic particles are added and mixed, or conductive potassium titanate short fibers and inorganic particles, or a suspension thereof are added to a polymer solution and mixed, then the solvent is removed. good. Further, the composite fiber can be spun by a melt spinning method, a wet spinning method, or a dry spinning method using an ordinary composite spinning device.

At this time, by using a coarse filter or a nozzle with a large diameter, it is possible to suppress an increase in nozzle back pressure due to clogging of the filter with conductive potassium titanate short fibers and inorganic particles. The drawing conditions for composite fibers are such that the drawing ratio is 1 in order to obtain good yarn physical properties and sufficient conductivity.
．． It is preferable that it is 5 to 4 times.

(Function) Although the function of the present invention is not clear, it is generally thought to be as follows. When only conductive potassium titanate short fibers are used in the polymer [A], the conductivity of the composite fibers is not efficiently developed. It is thought that this is because the contact probability between the conductive potassium titanate short fibers decreases due to orientation, and the conductivity of the composite fiber decreases. Therefore, by adding a specific amount of inorganic particles to the polymer [A] in addition to the conductive potassium titanate short fibers, the inorganic particles inhibit the orientation of the conductive potassium titanate short fibers, and therefore the conductive potassium titanate short fibers are inhibited. It is thought that the probability of contact between potassium short fibers increases, and it is possible to suppress a decrease in conductivity during spinning and drawing. Therefore, in order to efficiently express this effect, the diameter of the inorganic particles is preferably 0.01 μm or more, and more preferably 0.01 μm or more.
More preferably, it is 1μ or more. On the other hand, in order to maintain good yarn physical properties and processability of the composite fiber, the diameter of the inorganic particles is preferably 2 μm or less, more preferably 0.5 μm or less. Furthermore, by using white conductive inorganic particles as the inorganic particles, the conductivity of the composite fiber can be further improved. Furthermore, by adding these white inorganic particles to the polymer [A], the effect of improving the color tone of the composite fibers is also exhibited at the same time.

(Example) The present invention will be explained in more detail with reference to Examples below.
The technical scope of the present invention is not limited by this example. In addition, in the examples, the denier of the filament,
Strength, elongation, and color difference values are JIS-L-1070 and 1
073, and the electrical resistance value is YOKOG
It was measured with a high resistance measuring device manufactured by AWA-HEWLETT-PACKARD.

Example 1 Potassium titanate short fibers (manufactured by Otsuka Kagaku Q-Riki, trade name: "Dentol") whose surface was coated with tin oxide doped with a small amount of antimony (weight ratio of SnO:Sb:O-=99:1) JWK-200, specific resistance 10' ~ 10
1 Ω/c+s, average fiber diameter 0.4 u, average fiber length 20 μ, average coating thickness 0.02 μ) and 30 parts by weight of tin oxide doped with a small amount of antimony (5 by weight).
Made of titanium oxide particles (Mitsubishi Metals 91) whose surface is coated with nO-: Sb-0, = 9981), product name: "White conductive particles W-IJ, specific resistance io' ~ to" Ω/C1
A white conductive polymer was obtained by melt-kneading 10 ffiffi parts of polyethylene terephthalate (IV=0.35) and EtO (polyethylene terephthalate) (IV=0.35) and forming them into chips at 270°C. This white conductive polymer is used as a core component, and polyethylene terephthalate (IV=0.63) containing 3% titanium oxide is used as a sheath component, with a cross-sectional area ratio of 20:
Composite spinning was carried out at 280° C. and 2500 m/min to give a filament of 80 d/4f and drawn at 210° C. by a factor of 1.5. The obtained filament has a strength of 3
．． 1g/d, elongation 60%, color difference value 85, lOV
Electrical resistance value measured with (YOKOGAWA-HEfLE
TT-PACKARD high resistance measuring device) is 1. lX1
The resistance was 0.05Ω/cm. In addition, almost no interpressure such as thread breakage occurred during spinning, and the spinning properties were good.

The obtained filament was dissolved in a small amount of phenol/tetrachloroethane mixed solvent (phenol:tetrachloroethane = 3:2 by weight), and the length of the conductive potassium titanate short fibers was measured using an optical microscope. The diameter was 18μ, which was not significantly different from before kneading.

Example 2 In Example 1, instead of the white conductive particles W-t, titanium oxide particles (average particle size 0.2μ, color difference value 95) 10
Melt-kneading, spinning, and stretching were carried out under the same conditions as in Example 1 except that parts by weight were used, and the strength was 3.0 g/d and the elongation was 58%.
, color difference value 91, electrical resistance value 5.0X10' Ω/c
A white filament of ar was obtained.

Comparative Example 1 In Example 1, instead of using the white conductive particles W-1, 30 parts by weight of conductive potassium titanate short fibers WK200 and 70 parts by weight of polyethylene terephthalate (IV=0.35) were used.
A composite fiber was obtained by melt-kneading, spinning, and drawing under the same conditions as in Example 1 except that parts by weight were used, and the strength was 3.
．． 5g/d.

The elongation was 62% and the color difference value was 82, but the electrical resistance was 1.
0x10@Ω/car, and could not be put to practical use as a conductive fiber.

Comparative Example 2 Melt-kneading, spinning, and stretching were carried out under the same conditions as in Example 1, except that 40 parts by weight of conductive potassium titanate short fibers WK200 were used instead of using white conductive particles W-1 in Example 1. As a result, a white filament having a strength of 2.9 g/d, an elongation of 56%, a color difference value of 79, and an electrical resistance value of 8.4×10 5 Ω/C1 was obtained, but the fiber was poor in both fiber physical properties and conductivity.

Comparative Example 3 Conductive potassium titanate short fibers WK2 in Example 1
Instead of 00, tin oxide doped with a small amount of antimony (5nO- by weight: S b-0s = 99:
1) Short glass fibers (specific resistance 10'
−10” Ω/am, average fiber diameter 0.4μ, average fiber length 20μ, average coating thickness 0.02μ) to 30mmK.
The material was melt-kneaded, spun, and stretched under the same conditions as in Example 1 except for the following conditions: strength 3.1 g/d, elongation 60%, color difference value 84, electrical resistance value 3.5 x 10' Ω/ A white filament of Cm was obtained.

The obtained filament was dissolved in a small amount of phenol/tetrachloroethane mixed solvent (phenol:tetrachloroethane = 3:2 in weight ratio), and the length of the short glass fiber was measured using an optical microscope.The average length was 5 tt. Kneading 1]
It was significantly lower than 1J.

Comparative Example 4 In Example 1, conductive potassium titanate short fibers 1 (tW
Melt-kneading, spinning, and stretching were carried out under the same conditions as in Example 1, except that 40 parts by weight of white conductive particles W-1 were used without using K200, and the strength per unit was 3.2 g/d.

Elongation 65%, color difference value 87, electric resistance value 7.2 x 10
A white filament of @Ω/as was obtained.

As is clear from Table 1, which summarizes the results of the above examples and comparative examples, the composite fiber of the present invention has a strength of 3.0 g/
d or more, elongation of 58% or more, color difference value of 85 or more, and electrical resistance value of 5.0×10″Ω/ell or less.

(Effects of the Invention) The conductive composite fiber of the present invention has sufficient conductivity, high whiteness, and good spinnability and fiber properties, and can be used as a fiber for general clothing, dustproof clothing, antistatic clothing, etc. It is very effective.

Claims (6)

[Claims] (1) A conductive material in which one or more polymers [A] containing short potassium titanate fibers and inorganic particles whose surfaces are coated with a conductive metal compound are joined to a fiber-forming polymer [B] 1. A conductive composite fiber characterized in that the amount of inorganic particles contained in the polymer [A] is 5 parts by weight or more based on 100 parts by weight of the polymer [A]. (2) The conductive composite fiber according to claim 1, wherein the conductive metal compound is tin oxide, zinc oxide, indium oxide, cuprous iodide, or one or more metal compounds containing these as main components. . (3) Potassium titanate short fibers have a fiber diameter of 0.01 to 2.
The conductive composite fiber according to claim 1, wherein the conductive composite fiber has a fiber length of 1 to 500 μ. (4) The inorganic particles contained in the polymer [A] have a diameter of 0.
The conductive composite fiber according to claim 1, which is white inorganic particles having a diameter of 01 to 2μ. (5) The inorganic particles contained in the polymer [A] are tin oxide,
The conductive composite fiber according to claim 1, which is zinc oxide, indium oxide, cuprous iodide, and one or more conductive metal compounds containing these as main components. (6) The inorganic particles contained in the polymer [A] are tin oxide,
The conductive composite fiber according to claim 1, which is an inorganic particle coated with zinc oxide, indium oxide, cuprous iodide, and one or more conductive metal compounds containing these as main components.