Anti-static braided fabric and anti-static clothes

Abstract

Provided is an antistatic knitted fabric which is inexpensive, has durability, and is capable of ensuring a desired antistatic property. The anti-static knitted fabric is obtained by knitting a plurality of non-conductive wire rows (1) composed of non-conductive wires and at least one conductive wire row (2A) and at least one conductive wire row (2B) composed of conductive wires alternately. The conductive wire is a coated wire (20) obtained by using a tungsten wire (21) as a core wire and winding an organic fiber wire (22) around the tungsten wire (21). The distance between at least one conductive wire row 2A and at least one conductive wire row 2B which are adjacent to each other is 2.3-7 mm, and the number of unit winding turns of the organic fiber yarn 22 of the covering yarn is 600-1200 turns / m.

Description

Technical Field

[0001] The present invention relates to an antistatic fabric and antistatic clothing made from the antistatic fabric. Background Art

[0002] Japanese Patent Publication No. 5432841 (Patent Document 1) discloses a work fabric containing conductive fibers.

[0003] In addition, Japanese Patent Publication No. 6487228 (Patent Document 2) discloses a flame-retardant antistatic fabric composed of flame-retardant fiber filaments and conductive composite filaments. This patent also discloses that the fabric includes a knitted fabric and a woven fabric, wherein the conductive composite filaments are arranged in a grid pattern with gaps therebetween.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Publication No. 5432841

[0007] Patent Document 2: Japanese Patent Publication No. 6487228 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] In Patent Document 1, it is described that the knitted fabric or woven fabric means a fabric including a knitted fabric or a woven fabric composed of a knitted fabric or a woven fabric. However, Patent Document 1 does not describe any examples of a fabric containing conductive fiber filaments.

[0010] In addition, Patent Document 2 states in the specification that the fabric is a fabric including a circular knitted fabric. However, there are no specific examples of using a circular knitted fabric in Patent Document 2. Since the claims of Patent Document 2 state that the fabric is composed of conductive composite filaments arranged in a grid pattern with gaps therebetween, it is obvious that the fabric described in Patent Document 2 does not include a fabric in which the filaments are not arranged in a grid pattern.

[0011] In known documents including Patent Documents 1 and 2, although there is a description of an antistatic fabric made from a fabric containing conductive filaments, there is actually no specific disclosure. Since a fabric such as a circular knitted fabric has good elasticity, this fabric is used for work clothes, sportswear, and other articles that require durability. However, since the so-called conductive fibers in the fabric cannot be arranged in a grid pattern, in order to ensure the necessary antistatic performance, a large amount of conductive filaments must be used, which results in the problem that the antistatic fabric is expensive. In addition, if metal wires are used as the conductive filaments, repeated washing may cause breakage, thereby possibly leading to a decrease in antistatic performance and premature failure of durability.

[0012] An object of the present invention is to provide an antistatic fabric that is inexpensive, durable, and provides necessary antistatic performance.

[0013] Another object of the present invention is to provide an antistatic garment that is inexpensive and has high antistatic performance.

[0014] Solution to the problem

[0015] The present invention relates to an antistatic fabric composed of non-conductive filaments and conductive filaments. The antistatic fabric of the present invention is a fabric in which a plurality of non-conductive filament rows made of non-conductive filaments and one or more conductive filament rows made of conductive filaments appear alternately. The conductive filament is a covered filament formed by winding an organic fiber filament around a tungsten filament as a core filament.

[0016] Since tungsten filaments have excellent electrical conductivity, only a small number of conductive filament rows can ensure the desired electrical conductivity and durability. In addition, by appropriately selecting the number of winding turns of the organic fiber filament per unit length, the covered filament exhibits the desired electrical conductivity and durability. Therefore, when the covered filament is used in an antistatic fabric, the necessary electrical conductivity and durability can be ensured. If the number of winding turns of the organic fiber filament per unit length of the covered filament is reduced, the surface resistance value of the antistatic fabric decreases and the antistatic performance improves. However, if the number of winding turns of the organic fiber filament per unit length is reduced, the covering effect decreases, and the tungsten filament, which is the core wire of the conductive filament, becomes more vulnerable to damage or breakage due to the bending stress and torsional force applied during the washing process. As a result, even if the surface resistance value before washing can be reduced, the surface resistance value after washing will increase at an early stage of the washing process, leading to the problem of early deterioration of the antistatic performance. If the conditions of the present invention are met, the surface resistance value required for antistatic can be ensured without increasing the number of conductive filaments more than necessary, and an antistatic fabric with the required durability and antistatic performance can be provided at low cost.

[0017] Specifically, the distance (spacing) between two adjacent conductive filament rows in one or more conductive filaments is preferably 2.3 mm to 7 mm. The fineness of the organic fiber is preferably 20 to 100 denier, and the number of winding turns of the organic fiber filament per unit length in the covered filament is preferably 600 to 1200 turns / m. In this case, the wire diameter of the tungsten filament is preferably 30 μm or less. If the wire diameter of the tungsten filament is greater than this diameter, the tungsten filament will be more easily exposed on the surface of the conductive filament, making it easier to obtain higher-than-expected electrical conductivity. These conditions have been confirmed by experiments.

[0018] In particular, one or more conductive wire rows are composed of one conductive wire, and the wire diameter of the tungsten wire is preferably 16 μm to 22 μm. If the wire diameter of the tungsten wire is 22 μm or less, the tingling sensation caused by tungsten with high hardness can be suppressed. In addition, if the wire diameter of the tungsten wire is less than 16 μm, the resistance of the tungsten wire will exceed 100 Ω / 30 cm, and thus after 50 washings, the resistance of the conductive wire may exceed 11 the order of magnitude of 10

[0019] When using a hydrophilic organic fiber filament such as nylon, the fineness of the organic fiber filament 22 is preferably 70 to 80 denier.

[0020] If the fabric is circularly woven, it is preferable that at least the rows of conductive wires are semi-woven. Semi-woven knitting reduces the number of needles, which means less bending of the tungsten wire and further improves durability.

[0021] The antistatic clothing made of the antistatic fabric of the present invention has excellent antistatic performance, and is inexpensive and highly durable. Description of the Drawings

[0022] Figures 1(A) and 1(B) are schematic views for explaining the structure of a covered wire formed by double-winding an organic fiber filament around a tungsten wire as a core wire.

[0023] Figure 2 is a schematic view for explaining the structure of a fabric, in which the conductive wire row part is semi-woven.

[0024] Figure 3 is a graph showing the results of experiments performed on the examples and comparative examples. Detailed Description of the Invention

[0025] Embodiments of the present invention will be described in detail below. The antistatic fabric of the embodiment is basically an antistatic fabric woven by circular knitting using non-conductive wires and conductive wires. The non-conductive wires form the bottom wires. The antistatic fabric of the embodiment is a fabric woven by circular knitting such that a plurality of non-conductive wire rows made of non-conductive wires and one or more conductive wire rows made of conductive wires appear alternately at a certain interval (predetermined distance).

[0026] As shown in Figures 1(A) and 1(B), the conductive wire is a covered wire 20 formed by winding an organic fiber filament 22 around a tungsten wire 21 as a core wire. Specifically, the covered wire 20 constituting the conductive wire is made by stretching and fixing the tungsten wire 21, and winding the organic fiber filament 22 as a sheath wire around the tungsten wire 21 in one or more layers in a spiral shape (i.e., performing covering processing). Figures 1(A) and 1(B) show an example of double-winding.

[0027] As schematically shown in Fig. 1(A), the organic fiber filaments 22 are wound with gaps between the turns. From a macroscopic perspective, a part of the tungsten wire 21 is exposed. In fact, the organic fiber filaments 22 are thinner than the tungsten wire and have fine branches around it, so that the thick tungsten wire of the coated wire is covered by the slender and fluffy organic fiber filaments, making it invisible. However, from an electrical perspective, there are many exposed areas partially exposed on the surface of the tungsten wire. The surface resistance of the fabric is determined by the size of the exposed area and the distance between the conductive wire rows made of the coated wire.

[0028] In the embodiment, the number of turns of the organic fiber filaments 22 wound per unit length (the number of turns of the organic fiber filaments wound around the core wire of 1 m in a single helix or double helix) is preferably 600 to 1200 turns / m.

[0029] For example, the method for manufacturing the tungsten wire is as follows. First, a material composed of tungsten powder with a particle size of 5 μm each is press-molded and sintered into an ingot. Next, the tungsten ingot is forged, where the ingot is expanded by forging and compressing the ingot from each side, thereby forming the ingot into a wire. Then, wire drawing (drawing) is performed using a wire drawing die. The wire drawing is performed in the order of gradually decreasing aperture by using wire drawing dies with different apertures. The wire diameter of the tungsten wire 21 manufactured in this way used in the embodiment is 30 μm or less, and its surface roughness Ra is 0.20 or less. Specifically, the purity of tungsten in the tungsten wire is 99.9% or higher. The purity of tungsten in the tungsten wire can be 95% or higher, but is not limited thereto. The diameter of the tungsten wire 21 can be made smaller and has the property of being difficult to break or rupture even when repeatedly bent or twisted.

[0030] The organic fiber filaments 22 are not particularly limited and can be polyester filaments, polyethylene filaments, polyurethane filaments, polyvinyl chloride filaments, acrylic filaments, etc. having hydrophobicity. Nylon having hydrophilic characteristics can also be used. The specific organic fiber filaments 22 used in the embodiment are polyester filaments with a fineness of 75 denier. If the fineness of the organic fiber filaments 22 is small enough, the flexibility of the organic fiber filaments 22 will increase, making it easier to bend. This makes it easier to perform the coating process. The coated wire 20 used in the embodiment has excellent durability, so that the necessary durability can be ensured when used for the fabric.

[0031] Specifically, in the antistatic fabric of the embodiment, as Figure 2As shown, a plurality of non-conductive wire rows 1 made of non-conductive wires 10 and conductive wire rows 2A, 2B made of conductive wires are formed by semi-knitting in circular knitting, such that the conductive wire rows 2A, 2B appear alternately at intervals (predetermined distances or pitches). If the fabric is woven by circular knitting, it is preferable that at least the conductive wire rows are woven by semi-knitting, as in the embodiments. Using semi-knitting reduces the number of needles, thereby reducing the number of bent portions of the tungsten wires and further improving durability.

[0032] In the embodiment, the pitch (distance) between two adjacent conductive wire rows in the covered wire 20 and the number of turns wound per unit length of the organic fiber wire 22 are determined such that the surface resistance value of the fabric after at least 50 washes is within n×10 11 Ω / 30 cm or more (1 < n < 10) and m×10 11 Ω / 30 cm or less (1 < n < m < 10). If the surface resistance value is within 10 9 ~10 11 Ω or less, it exhibits an antistatic function; and if it is below this range, it has high conductivity and exhibits a function of quickly dissipating static electricity. If the surface resistance value exceeds this range, the electrical insulation becomes high, charging occurs, and the antistatic function decreases.

[0033] In the case of the circular knitted fabric of the embodiment, specifically, the distance (pitch) between adjacent conductive wire rows 2A and 2B is 2.3 mm to 7 mm, and the number of turns wound per unit length of the organic fiber wire 22 in the covered wire 20 is 600 to 1200 turns / m. Within these ranges, the required antistatic performance can be obtained. The shorter the distance (pitch) between the conductive wire rows 2A and 2B, the smaller the surface resistance value and the better the antistatic effect (static electricity prevention effect). However, since the amount of expensive conductive wire used increases, the price of the fabric also increases accordingly. In addition, the fewer the number of turns wound per unit length of the organic fiber wire 22 in the covered wire 20, the more the tungsten wire 21 will be exposed, the smaller the surface resistance value, and the better the antistatic effect. However, if the number of turns wound per unit length of the organic fiber wire 22 is reduced, the exposure amount of the tungsten wire 21 increases, and the surface resistance of the fabric using the conductive wire becomes too low, resulting in a short circuit and seriously damaging its practicality as an antistatic clothing. For these reasons, in fact, antistatic clothing that can utilize the fabric to exhibit antistatic performance and also ensure necessary durability has not been put into practical use.

[0034] Therefore, the present inventors have developed the antistatic knitted fabric of the present invention, which is inexpensive, has high durability, and exhibits antistatic performance that can be put into practical use.

[0035]

Example

[0036] In the following, based on Figure 3 the experimental results shown, examples that confirm the effects of the present invention will be described. Figure 3 The experimental results of a plurality of examples are shown, in which the number of turns wound per unit length of the organic fiber filaments 22 and the distance (pitch) between the conductive wire rows 2A and 2B are changed.

[0037] In Figure 3 the example, the wire diameter of the tungsten wire 21 used as the conductive wire in the covered wire 20 and the fineness of the organic fiber filaments 22 are kept constant. The wire diameter of the tungsten wire used is 20 μm. The organic fiber filaments 22 are hydrophobic polyester fiber filaments with a fineness of 75 denier or hydrophilic nylon fiber filaments with a fineness of 75 denier. The non-conductive filaments 10 are polyester fiber filaments with a fineness of 75 denier. The conductive wire rows (2A, 2B) are composed of one conductive wire. The conductive wires and non-conductive wires are combined to change the interval (pitch) between two adjacent conductive wire rows (2A, 2B) (changing the number of non-conductive wire rows 1), and a semi-woven fabric is made by circular knitting. A fabric for measurement (T-shirt type) is made using the fabric. The pitch refers to the distance between the centers of the conductive wire rows (2A, 2B). If the pitch is small, the number of conductive wires increases, resulting in an increase in cost; while if the pitch is large, the number of conductive wires decreases, but the antistatic performance deteriorates. Therefore, the pitch must be determined appropriately.

[0038] Specifically, in Figure 3 Examples 1 to 6, the distance (pitch) between the adjacent conductive wire rows 2A and 2B is 2.5 mm and 7 mm, and the number of turns wound per unit length of the organic fiber filaments 22 is 1200 turns / m and 600 turns / m. In Figure 3In the "Material" column, "PEs" represents polyester fiber and "Ny" represents nylon. In the "Anti-static" column, "Yes" or "No" indicates whether the fabric has been treated with anti-static agent. In the anti-static treatment, an anti-static agent is applied to the fabric so that static electricity is difficult to accumulate on the fabric surface. Note that the anti-static agent will peel off and lose its function after repeated washing. Therefore, whether to perform anti-static treatment is optional. The "0 Wash" column represents the surface resistance value measured before washing. Note that the surface resistance value refers to the maximum resistance value obtained by measuring the surface resistance values between "right sleeve and right front body", "front body and rear body", and "right sleeve and left sleeve" of the test suit. The distance between the two measurement electrodes is 30 cm, and the measurement method is based on JIS L 1930. The "50 Wash" and "100 Wash" columns represent the surface resistance values measured by the same measurement method as above after repeated washing 50 times and 100 times according to the 4M method of JIS L 1930. If the surface resistance value is less than 10 11 Ω, it can be evaluated that the surface has anti-static performance without static electricity. However, if the surface resistance value is within 10 12 Ω range, it is evaluated that the surface starts to carry static electricity and the anti-static performance starts to decline. If the surface resistance value is less than 10 2 Ω, there is a risk of electric shock due to discharge, but such a surface resistance value will not be reached unless the fabric is mainly composed of conductive fibers. When Figure 3 the "Yes / No of Broken Wire" column in is filled with "Yes", it means that the tungsten wire exposed between the organic fiber filaments 22 of the covering wire 20 is partially broken, or the surface of the tungsten wire is torn into small pieces or turned over to such an extent that even if the tungsten wire is not broken, its surface resistance value increases significantly. The "Yes / No of Broken Wire" is judged based on the electron microscope photo of the surface of the tungsten wire exposed between the organic fiber filaments 22 of the covering wire 20 and the surface resistance value after 100 washes.

[0039] According to Figure 3 the results of Examples 1 to 6 in, when the distance (spacing) between adjacent conductive wire rows 2A and 2B is set to 2.5 mm to 7 mm, and the number of turns per unit length of the organic fiber filaments 22 in the covering wire 20 is set to 600 to 1200 turns / m, the surface resistance value after "50 washes" is of the order of 10 11 Ω, and even after 100 washes, the surface resistance value is not high enough to determine that a broken wire has occurred. Therefore, it is confirmed that the necessary anti-static performance and durability can be obtained without increasing the usage amount of conductive wires.

[0040] If the spacing is less than 2.5 mm, the antistatic performance will not be higher than the necessary antistatic performance; and if the spacing is greater than 7.0 mm, the surface resistance will become too high and the necessary antistatic performance will not be obtained.

[0041] It has been found through experiments that a practical antistatic fabric can be obtained by forming one or more conductive wire rows into a single conductive wire row, setting the number of winding turns per unit length to 1100 - 1200 turns / m, and setting the distance (spacing) to 2.5 - 3.0 mm.

[0042] Furthermore, if the number of winding turns per unit length is reduced to as few as 200 turns / m, the surface resistance will become too small, making it easier to get an electric shock due to discharge. In addition, if the number of winding turns per unit length is set to, for example, 1300 turns / m, the surface resistance will become too high even if the spacing is short, and thus the required antistatic performance cannot be obtained.

[0043] Industrial Applicability

[0044] The present invention enables ensuring the surface resistance required for antistatic without increasing the number of conductive wires more than necessary, and can provide an antistatic fabric with necessary durability and antistatic performance at low cost.

[0045] Explanation of Reference Numerals

[0046] 1 Non - conductive wire row

[0047] 2A, 2B Conductive wire rows

[0048] 10 Non - conductive wire

[0049] 20 Covered wire (conductive wire)

[0050] 21 Tungsten wire

[0051] 22 Organic fiber wire.

Claims

1. An antistatic fabric made of non-conductive filaments and conductive filaments, comprising a fabric which is woven such that a plurality of non-conductive filament rows made of non-conductive filaments and one or more conductive filament rows made of conductive filaments appear alternately; wherein the conductive filament is a coated filament formed by winding an organic fiber filament around a tungsten filament as a core filament; the distance between two adjacent conductive filament rows among the one or more conductive filament rows is 2.3 mm to 7 mm, and in the coated filament, the number of winding turns of the organic fiber filament per unit length is 600 to 1200 turns / m.

2. The antistatic fabric according to claim 1, wherein the diameter of the tungsten filament is 16 μm to 22 μm, and the fineness of the organic fiber filament is 20 to 100 denier.

3. The antistatic fabric according to claim 1, wherein the organic fiber filament has a hydrophobic organic fiber filament surface which has an antistatic structure.

4. The antistatic fabric according to claim 3, wherein each of the one or more conductive filament rows is composed of one conductive filament row, the number of winding turns of the organic fiber filament per unit length is 1100 to 1200 turns / m, and the distance is 2.5 to 3.0 mm.

5. The antistatic fabric according to claim 2, wherein the organic fiber filament is a hydrophilic organic fiber filament.

6. The antistatic fabric according to any one of claims 1 to 5, wherein the fabric is woven by circular weaving.

7. The antistatic fabric according to claim 6, wherein the circular weaving includes at least semi-weaving of the conductive filament row.

8. An antistatic garment made using the antistatic fabric according to claim 7.

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