JPH11124775A - Fabric having electrode function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode material useful for a detector for a material, etc., and excellent in bending durability, etc. SOLUTION: This fabric having electrode function used in a system for detecting a material, for detecting presence or absence of the material in a space to be detected by generating a faint electric field and utilizing the change of the electric field or the change in capacitance is the one obtained by laminating an electroconductive layer 2 on a fabric 3 to provide an electrode-integrated type fabric, and using the electrode-integrated type fabric as the electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detection apparatus that generates a weak electric field between electrodes and detects a disturbance of the weak electric field or a system that detects a change in capacitance, for example, on a seat. Regarding the electrode material used in the presence detection device that detects the presence or absence of the human body, more specifically,
Systems that provide services such as information communication only when a person is in the seat, control of room acoustics, air conditioning and lighting, grasp of occupants in transportation, etc. The present invention relates to a cloth having an electrode function excellent in bending durability and the like, which can be used for a control system of an airbag device for preventing the airbag device, a system for detecting whether a person is on a bed, or the like.

[0002]

2. Description of the Related Art An apparatus for generating an electric field between electrodes, detecting a change between the electrodes, and detecting the presence of an object or a person is, for example,
It is disclosed in Japanese Patent No. 1939785, JP-A-6-249963, JP-A-6-308254, and the like. As a material of the electrode material in a system that generates an electric field between the electrodes and detects the fluctuation between the electrodes, conventionally, a metal plate such as copper, brass, and aluminum, and in particular, in applications requiring flexibility, Materials such as metal foil, or woven or knitted fabric made of metal fiber, or cross woven or knitted fabric made of metal fiber and synthetic fiber, or composite woven fabric or composite knit of metal fiber and synthetic fiber are used, and these are used as electrodes. It has been treated as a material alone. And these electrode materials were made to function by attaching to each member according to a situation, respectively. Japanese Patent No. 2541990 discloses that a nickel-plated synthetic fiber is fused to an automobile decorative member and used for an occupant detection sensor.

[0003]

An electrode material made of a metal plate has high rigidity against bending and excellent durability against external force, but is extremely hard and heavy, and therefore directly or indirectly touches the human body. It gives a very unpleasant feeling of use in contacting applications. Therefore, the metal plate must be installed at a place away from the surface of the cloth, and to increase the detection accuracy, the voltage must be increased to increase the electric field.
The electric efficiency is deteriorated, the life of each part is shortened, and the electrode material is separated from the object to be detected, so that the accuracy of the detection system is deteriorated. Therefore, if the electrode material is brought closer to the object to be detected, that is, if the electrode plate is made thinner and flexible to arrange it on the surface of the cloth, rigidity and bending durability against external force are reduced, and the material is extremely plastic and deformable. This makes it easier to tear or tear, and also makes it difficult to sew or adhere to the fabric material. In addition, inconveniences such as a poor feel are caused. A woven fabric, a knitted fabric, a nonwoven fabric, etc. made of metal fibers have improved flexibility to some extent, but are inferior in durability such as flexibility, and are also plastic and easily deformed. A cross-woven or cross-knitted mixture of metal fibers and synthetic fibers slightly improves flexibility and bendability, but is still not preferable as an electrode material because the metal fiber portion has poor bending durability. Furthermore, it is difficult to form the electrode portion in a predetermined shape or in a predetermined place even if the electrode portion made of conductive fiber is formed on the fabric at the time of weaving or knitting. There is a problem that the manufacturing cost is increased. In addition, a fiber using a yarn spun with a conductive substance is also known, but has a large surface resistance and is not suitable for use as an electrode material.

[0004]

As a result of intensive studies to solve the above problems, it has been found that the above problems can be solved by developing a fabric having an electrode function, in which the electrode material is integrated. That is, the present invention is characterized by comprising an electrode-integrated fabric obtained by laminating a conductive layer on a fabric, generating a weak electric field from the laminated conductive layer, and utilizing the change, or the change in capacitance. Is an electrode material used in an object detection system that detects whether or not there is an object in a space to be detected by using the object detection system.

[0005] Among the methods for forming a conductive layer on a cloth, methods for forming a conductive layer by coating include a method of coating a conductive fine particle paste on a cloth and a method of printing by printing. Further, as a method of forming a conductive layer by sticking, there is a method of laminating a film made of conductive fine particles on a cloth. As a place where the conductive layer is formed, for example, in a seat, a conductive layer may be formed on a skin material of the seat, or a cloth (for example, a nonwoven fabric) formed with the conductive layer may be a cushion material such as a skin material and a foam layer. It may be sandwiched between. The conductive layer may be formed on the entire surface of the cloth or on a part of the cloth as necessary. As the kind of material, warp knitting, weft knitting, lace knitting and various knittings applying those knitting methods, or plain weave, twill weaving, satin weaving and various textiles applying each weaving method, and further non-woven fabrics Any of them can be adopted and is not particularly limited. Further, the material of the fiber cloth used is, for example, polyamide fiber such as nylon 6, 66, 46; aromatic polyamide fiber (aramid fiber) represented by a copolymer with paraphenylene terephthalamide and aromatic ether; Polyphenylene benzobisoxazole; polyester fiber represented by polyalkylene terephthalate; wholly aromatic polyester fiber (polyarylate fiber); vinylon fiber; rayon fiber; polyolefin fiber such as ultrahigh molecular weight polyethylene; polyoxymethylene fiber; Sulfone fibers such as fon and polysulfone; polyetheretherketone fibers; polyetherimide fibers; carbon fibers; synthetic fibers such as polyimide fibers, chemical fibers such as rayon, and natural fibers such as cotton, silk, and wool. In some cases, inorganic fibers such as glass fibers and ceramic fibers may be used alone or in combination. Examples of the conductive material to be applied include fine metal particles such as gold, silver, platinum, copper, iron, nickel, aluminum, zinc, and chromium, and alloys thereof, or copper oxide, zinc oxide, tin oxide, and zinc oxide. Conductive metal oxide fine particles such as copper oxide, tungsten oxide, zirconium oxide, and indium oxide, and conductive metal compound fine particles such as copper sulfate, cuprous iodide, zinc iodide, and cadmium sulfide are used. The content of these conductive fine particles cannot be specified uniformly because it varies depending on the type of conductive fine particles used, but the electric resistance value of the conductive fibers is 10%.
^It is preferably ² Ω / □ or less, particularly preferably 1 Ω / □ or less.

A protective layer made of an insulating soft resin is further formed on the electrode portion formed by the above method to protect the conductive layer of the electrode portion from oxidation or to prevent damage. The resistance value of the material may not be changed. As the insulating soft resin, acrylic resin, vinyl chloride resin, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polyurethane, polyamide and the like can be used. As the acrylic resin, alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate,
Homopolymers of alkyl methacrylates such as ethyl methacrylate, butyl methacrylate, and hexyl methacrylate can be used, and polyalkyl methacrylate is particularly preferred. The protective layer can be formed by electrodeposition coating, coating, lamination, or the like.

Further, it is possible to impart flame retardancy to these conductive layers or insulating layers. Examples of the flame retardant to be used include a halogen compound, a phosphorus compound and a metal compound. For example, halogen compounds include tetrabromobisphenol A, tetrabromobisphenol A bisdibromoethyl ether, tetrabromobisphenol A epoxidized oligomer, tetrabromobisphenol S, hexabromocyclododecane, decabromodiphenyl ether, and octabromodiphenyl. Examples of phosphorus compounds such as ether include ammonium polyphosphate, guanidine phosphate, ammonium phosphate, halogenated phosphate, melamine phosphate, triphenyl phosphate, TCP, propylphenyl diphenyl phosphate, halogenated alkyl phosphate, and polyhalogenated polyphosphate. Metal compounds, such as antimony trioxide, antimony pentoxide, zinc borate, tin oxide,
Examples include molybdenum zinc oxide, molybdenum oxide, aluminum hydroxide, and magnesium hydroxide. These flame retardants may be used alone or in combination of two or more.

FIG. 1 is a perspective view showing an example of mounting an electrode material 2 on a seat 1 when the electrode material of the present invention is used in a presence detection device for detecting the presence or absence of a human body on a seat. FIGS. 2, 3 and 4 are cross-sectional views showing examples of lamination when the electrode material of the present invention is used. As a preferred use mode of the electrode material of the present invention, there is a material in which a conductive layer is integrated by coating or laminating on a surface of a fabric constituting a skin material such as a seat. In this case, the place where the conductive layer is attached may be an appropriate portion of the fabric according to the application. In this case, it is preferable to arrange an insulating layer between the cloth and the conductive layer. The structure of disposing the conductive layer on the side opposite to the cloth is not particularly limited, but it is preferable to dispose another cloth, foam, or the like directly on the conductive layer or, preferably, via an insulating layer.
FIG. 2 shows a laminate example suitable as a seat material of a seat, in which a conductive layer 2 and a foam layer 4 (for example, polyurethane or the like) are sequentially attached under a fabric 3 of a skin material. FIG. 3 shows an insulating layer 5 between the cloth 3 and the conductive layer 2 and between the conductive layer 2 and the foam layer 4 of FIG.
Is an example of lamination. FIG. 4 shows the cloth (skin material) 3 of FIG.
This is a lamination example in which a conductive layer 2 and a fabric (nonwoven fabric) 6 are arranged between the conductive layer 2 and the foam layer 4.

The electrode material thus manufactured has sufficient bending durability and can be adapted to any shape. Therefore, it is easy to integrate the electrode material with a fabric, and it is necessary to prepare an electrode material suitable for each condition. Can be. The performance of each electrode material coated on the cloth can be determined from the measured values in Table 1 as substitute numerical values. The measuring method of each property value is as follows. The tear strength is JIS L 1096
The single tongue method, rigidity were measured according to JIS L 1096 cantilever method, air permeability was measured according to JIS L 1096 Frazier method, wrinkle resistance test was performed according to JIS L 1096 A method, and anti-fatigue fatigue test was measured according to JIS P 8115.

[0010]

【Example】

Example 1 A brushed back surface of a high-density knitted knitted fabric (weight per unit area: 475 g / m ² ) was coated with a nickel fine powder-dispersed polyurethane resin (viscosity: 25,000 to 30,000 cps) using a knife coater and dried at 130 ° C. for 1 minute. After drying, a cloth electrode material having a film thickness of 70 μm and a surface resistance value of 0.8Ω / □ was obtained. Table 1 shows the performance of this electrode material.

Comparative Example 1 A rolled copper foil having a thickness of 0.1 mm was used as an electrode material. Table 1 shows the performance of this electrode material.

Comparative Example 2 A metal mesh having a thickness of 0.42 mm using a tin-plated copper wire was used as an electrode material. Table 1 shows the performance of this electrode material.

[0013]

[Table 1]

A chair skin material was prepared using the cloth sheet electrode material obtained in Example 1. Further, the electrode materials of Comparative Examples 1 and 2 were respectively joined to the uncoated fabric of Example 1 to produce chair skin materials, and the produced skin materials were evaluated for actual use for one year. Table 2 shows the evaluation results.

[0015]

[Table 2]

[0016]

According to the present invention, it is possible to provide an electrode-integrated fabric which has a small change in resistance value even when stretched, is less likely to wrinkle, and is less likely to break, so-called, excellent in bending durability. In automobile seats, etc., by providing electrodes at multiple locations, it is possible to detect and grasp the occupant's seating position and posture, and it is also possible to control the operation of occupant restraint devices such as airbags Become.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a seat incorporating an electrode material of the present invention.

FIG. 2 is a cross-sectional view showing a lamination example in which the electrode material of the present invention is incorporated.

FIG. 3 is a cross-sectional view showing another example of lamination incorporating the electrode material of the present invention.

FIG. 4 is a sectional view showing still another example in which the electrode material of the present invention is incorporated.

[Explanation of symbols]

 Reference Signs List 1 seat 2 conductive layer 3 cloth (skin material) 4 foam layer 5 insulating layer 6 cloth (non-woven fabric)

Claims (3)

[Claims] 1. An object detection system for generating a weak electric field and utilizing its change or utilizing a change in capacitance to detect whether or not an object is present in a detection space. A cloth having an electrode function formed by laminating. 2. The cloth having an electrode function according to claim 1, wherein the cloth is laminated by applying a conductive layer to the cloth. 3. The fabric having an electrode function according to claim 1, wherein the conductive layer is laminated on the fabric by sticking.