JPH03237799A - Conductive woven cloth and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain woven cloth excellent in electric conductivity without spoiling the feeling as a cloth, by forming an electrically conductive coating film composed of oxygen deficiency N-type semiconductor material, on the surface of the woven cloth. CONSTITUTION:Woven cloth composed of synthetic fiber like polyester is used as woven cloth turning to base cloth. Electrically conductive coating film formed on the surface of the woven cloth is constituted of oxygen deficiency N-type semiconductor material. As regards said material, the following can be used; tin oxide, indium oxide, zink oxide, and indium oxide doped with tin. Since the electrically conductive coating film composed of semiconductor material is faintly colored and has no luster like metal, appearance grade for clothing use is not deteriorated. It is not preferable for the thickness of the above coating film to exceed 5mum, because the flexibility of woven cloth is decreased, the feeling of cloth is spoiled, and further cracks are caused in the coating film by bending.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a conductive fabric suitable for electromagnetic shielding material and a method for producing the same.

(Prior Art) In recent years, there has been a trend in the field of textiles to develop textile materials that place emphasis on functionality, and the desired functionality has become diverse, and higher performance has been required.

Under these circumstances, many proposals have been made regarding conductive textiles and their manufacturing methods.
There are two main types of materials that have a surface conductive layer, and their manufacturing methods include a method for obtaining conductive filament yarn by melt-spinning a master chip in which a conductive substance is kneaded into a polymer; There are two main types of methods: forming a conductive layer on the surface of a fabric by plating, thermal spraying, vapor deposition, etc.

However, all of these proposals have advantages and disadvantages, and are not fully satisfactory in all aspects. That is, with respect to conductive fibers, in order to obtain high conductivity, it is necessary to mix a large amount of conductive substance, which has the disadvantage of significantly reducing the physical properties of the fibers.

In addition, in order to eliminate such drawbacks, for example.

Fibers made of filaments with a core-sheath type filament structure have been proposed, as in JP-A-55-1337, but since the conductive layer is covered with an insulating layer, the level of Currently, only conductive performance has been achieved. moreover.

In the manufacturing method, a master chip kneaded with metal or carbide fillers is used for melt spinning, which causes problems such as screw wear and nozzle clogging. On the other hand, as described in JP-A-61-102478, the technique of imparting electrical conductivity by plating has a major problem in terms of the working environment because it uses a metal salt solution. In addition, with regard to technology that imparts conductive performance through thermal spraying,
The drawback is that it is difficult to control the thickness of the conductive layer, making it impossible to form a uniform film. Furthermore, the fabric obtained by the above manufacturing method has a luster characteristic of metal.

The appearance quality is poor, and the unevenness of the surface of the fabric is too large for the conductive layer, so defects occur everywhere in the conductive layer, making it impossible to maintain high conductive performance. However, if the conductive layer is made thicker, the roughness and stiffness characteristic of filament yarn fabrics will be further promoted, resulting in a complete lack of suitability as clothing.

(Problem to be solved by the invention) The present invention was made in view of the above-mentioned current situation.
The purpose of this invention is to produce a fabric that has excellent electrical conductivity without impairing the tactile feel for clothing.

(Means for Solving the Problems) As a result of intensive research to solve the above problems, the present inventors have selected a conductive material that can exhibit high performance and kept the film thickness below a certain level. This ensures that the tactile feel of the garment is not compromised.

By discovering that it is possible to obtain an excellent conductive fabric, and by adopting a method that controls the unevenness of the fabric surface and forms a conductive thin film on the organic fiber fabric,
The present invention was achieved by discovering that unprecedented high conductive performance could be obtained.

In other words, 1 the present invention provides that ``the surface of the fabric has a conductive coating made of an oxygen-deficient n-type semiconductor material with a thickness of 5 μm or less, and the surface resistance of the conductive coating is 50Ω/□ or less. A first step of making the surface roughness of the woven fabric 10 μm or less and a second step of forming a film of an oxygen-deficient n-type semiconductor material on the surface of the woven fabric by physical vapor deposition. ``A method for manufacturing a conductive fabric characterized by the following characteristics.''

Hereinafter, one aspect of the present invention will be explained in detail.

First of all, the conductive fabric of the present invention has a conductive coating made of an oxygen-deficient n-type semiconductor material having a thickness of 5 μm or less on the surface of the fabric.

As the woven fabric serving as the base fabric, a filament woven fabric made of synthetic fibers such as polyester is preferably used. The conductive film formed on the surface of the fabric must be composed of an oxygen-deficient n-type semiconductor material, and examples of this oxygen-deficient n-type semiconductor material include tin oxide, indium ilide,! Examples include zinc dodecide and indium oxide doped with tin (hereinafter referred to as ITO), among which tin oxide and indium oxide are preferably used, and IT◯ is even more preferred. The conductive film made of a semiconductor material is light in color and does not have the luster of metal, so it does not impair the appearance quality for clothing.

The thickness of the conductive coating must be 5 μm or less; if the thickness exceeds 5 μm, the flexibility of the fabric will decrease;
This is not preferable because the tactile feel of the garment is impaired and furthermore, the coating is torn due to bending.

The conductive film needs to have a 9 surface resistance of 50 Ω/□ or less, preferably 20 Ω/□ or less, more preferably 1 Ω/□ or less. This surface resistance is 50Ω/□
If it exceeds this value, the effectiveness as an electromagnetic shielding material is substantially lost.

The conductive fabric of the present invention as described above can be manufactured by the following method.

First, a first step is performed to reduce the surface roughness of the fabric to 10 μm or less. What does surface roughness mean here?

It is calculated from the cross-sectional shape of the fabric drawn two-dimensionally using a stylus-type surface roughness measuring meter. A reference line is set in the cross-sectional shape, and the maximum peak height (dm) and maximum valley depth (dr) are calculated. Read and calculate using the following formula (1).

Surface roughness = d m + d r (μm) ---(
1) If the surface roughness exceeds 10 μm, the conductive film will not be uniformly formed in the first film forming step.

Moreover, the coating may be torn, making it impossible to obtain sufficient electrical conductivity. In order to make the surface roughness of the fabric 10 μm or less, first steps (a) and (b) are required.

It is necessary to employ a combination of at least two or more of the methods in (c).

(a) Weaving is carried out so that the sum of the cover factors in the warp and weft directions is 1800 or more.

(b) Calendaring the fabric.

(c) Applying a resin coating to the surface of the fabric.

The total cover factor here is calculated by the following formula (2), and is 1800 or more for plain woven fabrics, 2500 or more for diagonal woven fabrics, and 300 for satin woven fabrics.
It is preferable that it is 00 or more.

Sum of cover factors = , ×zoite-+ + K 2
However, +Kl is the warp density (books/inches), and 2 is the weft density (
D is the warp fineness (denier).

D2 is the weft density (denier). ) The above calender treatment (b) is a treatment in which the surface of the fabric is smoothed by passing the fabric through the nipping portion of one or more pairs of heated and pressurized rolls, and includes the universal calender method and the friction calender method.

This can be carried out by the Schreiner calendar method or the like. Also, the resin coating in (c) above.

This involves applying a resin to the surface of the fabric. Either dry or wet coating methods may be used, but it is preferable to use the dry method as it can form a smooth, non-porous coating. method, roll coach ink method, bar coating method, etc. may be employed as appropriate depending on the resin used.

The resin for resin coating is not particularly limited, but in consideration of the formation of a conductive film in the second step, a hydrophobic resin is preferable.

Examples include resins such as acrylic esters, urethane, and vinyl chloride. The thickness of the coating resin film formed here is not particularly limited, but it is preferably the minimum thickness that can cover the surface of the fabric.

In the method of the present invention, the surface roughness is reduced to 10 μm in the first step described above.
A second step of forming a film of an oxygen-deficient n-type semiconductor material on the surface of the fabric described below by physical vapor deposition is performed. This second step is a step of forming a conductive layer on the surface of the fabric.

The physical vapor deposition method referred to herein is a method in which a solid is vaporized using heat, light, an electron beam, etc., and then deposited as a solid again on the surface of a sample, for example.

Examples include ion blasting method, sputtering method, and reactive vapor deposition method. The ion blating method is a method in which evaporated atoms are attached to a substrate by the action of ions.Ions are usually obtained by ionizing an inert gas. The sputtering method involves heating a solid in a low-pressure gas.

This is a method in which atoms are ejected from the surface of the solid and attached to the base material by bombarding the solid with ions. Further, the 9-reactive vapor deposition method is a method in which atoms evaporated by heat are caused to react with a gas such as oxygen and attached to a base material. In the manufacturing method of the present invention, any of the above methods can be applied in the second step of the present invention in which a conductive film is formed on the surface of the fabric. As the oxygen-deficient n-type semiconductor material, the aforementioned tin oxide, indium oxide, zinc oxide, IT◯, etc. are used.

The present invention has one or more configurations.

(Function) In the method of the present invention, when the surface roughness of the fabric is reduced to 10 μm or less in the first step, the second surface becomes very smooth and uniform. When a film of oxygen-deficient n-type semiconductor material is formed by a vapor phase deposition method, a very thin film of 5 μm or less has a surface resistance of 5 μm.
Uniformly formed at 0Ω/□ or less. This film is made of a semiconductor material, but when the film is made of a semiconductor material in this way, it does not have the metallic luster caused by metal materials and exhibits an extremely excellent appearance quality, and is not commonly used. It also fully demonstrates its performance as an electromagnetic shielding material. Also.

This coating is very thin, 5 μm or less, and by making the coating thin in this way, the flexibility and feel of the garment can be maintained very well.

(Example) Next, the present invention will be specifically explained with reference to Examples. The measurements and evaluations of the fabrics in the Examples were performed by the following methods.

(1) Surface roughness ■ Using surface roughness measuring instrument 5E-3AK manufactured by Koita Institute, Y-axis magnification is 100 times, Z-axis magnification is 500 times, and pitch magnification is 2.
Calculation was made by averaging five arbitrary points on the sample under measurement conditions of 00 times magnification and a scanning distance of 1 cm.

(2) Surface resistance According to AATCC test method (76, 84).

Calculated.

8 (3) Appearance Quality The following three levels of judgment were made with the naked eye for color and gloss.

○: Appearance quality is good △: Appearance quality is average Δ: Appearance quality is poor The percentage of bending resistance that the treated fabric has when it is set to 100 is calculated using the following equation (4).

The results were evaluated in the following three stages.

(However, L is the bending resistance of the untreated fabric.

L is the bending resistance of the treated fabric. ) ○: The value calculated from formula (4) is 80% or more Δ: (4
) The value calculated from the formula is 65 to 80% ×: (The value calculated from the formula (1) is less than 65% Example 1 A polyester fabric with a total cover factor of 2000 is used as the base fabric, and this fabric has a universal Calendar treatment was performed using a calender method at a pressure of 40 kg/ci.

The surface roughness of the fabric at this time was 7 μm. Next, R
Using an F ion brating device, using IT○ (manufactured by Nihon Kogyo ■, In: 5n = 95: 5) as a target, while generating plasma at an argon gas introduction rate of 30 cc/min, the film formation rate was 70 people. /sec, RF output of 200 W and a film thickness of 5 μm on the above fabric.
A conductive fabric of the present invention was obtained by forming a film of T○.

For comparison with the present invention, a comparative conductive fabric (Comparative Example 1) was produced in the same manner as in Example 9, except that the calender treatment was omitted.

In addition, for comparison with the present invention, a conductive material for comparison was prepared using the same method as in Example 9, except that the calender treatment was omitted and the film thickness of IT○ was 7 μm. A synthetic fabric (Comparative Example 2) was produced.

The performance of the present invention and comparative conductive fabrics was measured.

The results are shown in Table 1.

Table 1 As is clear from Table 1, the conductive fabric of the present invention that satisfies all the constituent requirements has sufficient performance as an electromagnetic shielding material (surface resistance of 50Ω/□ or less) and is suitable for use as clothing. It was an excellent fabric that did not impair its feel.

Ta.

The performance of the present invention and comparative conductive fabrics was measured.

The results are shown in Table 2.

Table 2 Example 2 A polyester satin fabric with a total cover factor of 3500 was used as the base fabric, and a polyurethane resin (Heimlen Y-210, manufactured by Dainichiseika Industries, Ltd.) was dry coated on the surface of this fabric using a knife coating method. It was filmed. The surface roughness at this time was 3 μm. After that, using the same equipment as used in Example 1, the coating surface IT○ was formed to a film thickness of 3 μm at the same film forming speed and the same RF output.2 The conductive fabric of the present invention was manufactured.

For comparison with the present invention 9 Conductive fabric for comparison (Comparative Example 3) made in exactly the same manner as in this example except that nickel was used instead of IT○ used as a target during film formation in this example As is clear from Table 2,
The conductive fabric of the present invention, which satisfies all the constituent requirements, has excellent performance as an electromagnetic shielding material (surface resistance of 50 R/R or less).
It was an excellent fabric that had sufficient properties and did not impair the feel of clothing. On the other hand, Comparative Example 3, which did not satisfy one of the constituent requirements of the present invention, could not satisfy any of the requirements.

(Effects of the Invention) According to the present invention, a conductive fabric that is effective as an electromagnetic shielding material can be manufactured without impairing the feel of the fabric for clothing.

Claims (2)

[Claims] (1) Oxygen deficiency n with a film thickness of 5 μm or less on the surface of the fabric
1. A conductive fabric comprising a conductive coating made of a type semiconductor material, and having a surface resistance of 50Ω/□ or less. (2) A method comprising a first step of making the surface roughness of the fabric 10 μm or less, and a second step of forming a film of an oxygen-deficient n-type semiconductor material on the surface of the fabric by physical vapor deposition. Method for manufacturing conductive fabric.