JPS61201045A - Deformed conductive knitted cloth - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a deformable conductive knitted fabric whose electrical resistance value changes when stretched or compressed in any direction.

<Prior art> Pressure-sensitive conductive elastomer sheets and stretchable conductive elastomer sheets have been used as materials whose resistance value changes when deformed, but both require a considerable amount of conductive filler to be added to the elastomer. Since it is mixed in, the inherent rubber elasticity of the elastomer is significantly reduced, resulting in a disadvantage of low repeated durability. In knitted fabrics, the deformation mainly corresponds to the deformation of the tissue structure (for example, in the case of woven fabrics, changes in the angles formed by warp and weft yarns, or deviations, etc.), so they have high repeated durability. On the other hand, no research and development has been conducted on the relationship between changes in the tissue structure of knitted fabrics and changes in electrical resistance. To date, no deformable conductive knitted fabric has been developed that can detect the structural deformation of the fabric as a change in resistance value.

<Problems to be Solved by the Invention> The present invention solves the above-mentioned drawbacks of conventional materials whose resistance value changes due to general deformation. It is an object of the present invention to provide a deformed conductive knitted fabric in which the electrical resistance of the knitted fabric is changed by deformation of the structure of the knitted fabric.

Means for Solving the Problems> An object of the present invention is to provide a deformable conductive knitted fabric whose electrical resistance value changes when stretched or compressed in any direction, the deformable conductive knitted fabric being This problem can be solved by a modified electrically conductive knitted fabric characterized in that electrical conductivity or electrical insulation at the intertwined portion of the yarns satisfies the following conditions.

■ Among all the intertwined parts in a given area of the knitted fabric, the number of intertwined parts that are electrically insulated is 11, and the number of intertwined parts that are electrically conductive is t2. The value of the ratio t, μ2 is measured per square inch, l/
Must be 9 or above.

■ Electrical insulation between multiple intertwined portions of adjacent yarns at a constant length in the longitudinal direction of each yarn that makes up the knitted fabric! If the number of intertwined parts that are in a state of conduction is ykm, and the number of intertwined parts that are electrically conductive is m2, then the ratio m is
The value of 17m2 shall be 179 or more as measured per inch length.

The deformable conductive knitted fabric described herein means a knitted fabric whose resistance value in the deformation direction changes by one order of magnitude or more when a deforming action such as stretching or compression is applied. In addition, the structure of the fabric may be plain weave, twill weave, or satin weave, but plain weave has a particularly dense structure and is excellent in repeat durability, and its resistance value changes with high sensitivity to minute deformations. So it's preferable. In addition, the knitting structure may be either warp knitting or weft knitting, tricot knitting, jersey knitting, elastic knitting, arm-to-shoulder knitting, etc., but especially in the case of /'P-ru knitting, teeth,
This can be achieved by appropriately selecting a deformed conductive structure that is substantially uniform in any direction of the knitted structure. The shape of the knitted fabric is
It includes all shapes using the texture of knitted fabrics, such as sheets, cylinders, etc. In addition, the yarns constituting the knitted fabric include monofilaments and multifilaments spun by ordinary melting and wet spinning machines, spun yarns made of short fibers, twisted yarns of these yarns, films and sheets, etc.
An elongated shape or a convergence thereof can be used. The materials include all electrically insulating synthetic polymers such as nylon and esters, synthetic fibers such as cellulose and other regenerated cellulose fibers, electrically insulating natural polymers such as natural rubber, and electrically insulating inorganic fibers such as glass. Only certain parts of these threads are electrically insulated, and other parts are coated with a conductive material such as copper, nickel, silver, or carpin by plating, coating, thermal spraying, or other conductive means. Provided with electrical conductivity. In particular, in the case of multifilaments or spun yarns, each filament or short fiber comes into contact with each other under minute stress, which is preferable for forming a highly sensitive deformable conductive knitted fabric. In addition, the electrically insulated state as used in the present invention means a state in which the electrical resistance value between two needle terminals is 100 or more according to the electrical resistance value measurement method described in the examples, and Similarly, the electrically conductive state means a state in which the electrical resistance value between the two needle terminals is less than 10'Ω.

The present inventors discovered that when a knitted fabric is subjected to a deformation action such as stretching and compression, the angle formed by two intersecting threads changes due to the deformation of each thread itself, as well as the displacement and twisting of the intertwined parts of each prefecture. The inventors discovered that this change causes a change in one tissue structure, and that this change in tissue structure induces a change in the resistance value of the knitted fabric, leading to the development of the deformed conductive knitted fabric of the present invention.

The intertwined portion in the present invention refers to a portion where each prefecture intersects, and does not necessarily need to be in contact with each other. In the case of woven fabrics, it is the intersection of warp and weft yarns, and in the case of knitted fabrics, it is the intersection of loops.

The invention will now be described in detail with reference to the accompanying drawings, which schematically illustrate embodiments of modified electrically conductive knitted fabrics of the invention.

FIGS. 1 and 2 show schematic diagrams of the structure of the deformed conductive knitted fabric. Figure 1 shows the case of plain woven fabric, and Figure 2 shows the case of jersey knitted fabric.

In FIG. 1, A indicates the warp, and B indicates the weft. Moreover, FIGS. 3 and 4 show schematic diagrams of yarns constituting the modified electrically conductive knitted fabric. (Figure 3 shows a part of the threads constituting the plain woven fabric and Figure 4 shows a part of the threads constituting the jersey knitted fabric).The shaded areas represent the electrically insulated areas, and the white areas represent the electrically conductive areas.

Remaining 8 Below, the intertwined portions that are electrically insulated or the intertwined portions that are electrically conductive in the present invention refer to the two intertwined portions.
This means that the threads are electrically insulated and electrically conductive through the intertwined parts, for example, 1 and 2, 3 and 4 in FIG. 5 and 6, 7 and 8 in Figure 2
is electrically insulated or electrically conductive. In addition, the term "adjacent interlaced parts" refers to the area between adjacent interlaced parts of a single thread, but it actually means between two adjacent parts on the opposite side of the interwoven part. However, in Figure 3, between 9' and 10', 10'
and 11, in FIG. 4, between 13' and 14', and between 14' and 15'. In addition, 9゜10.11 in Fig. 3.
The hatched areas surrounded by dotted lines at 13, 14, and 15 in Figure 4 mean intertwined areas, and 9', 10', and 1 in Figure 4
f, Fig. 4 +7) 13', 14', 15'+7
3. The white part represents the part on the opposite side of the interlaced part.

In addition, between interlaced parts that are electrically insulated or electrically conductive, adjacent interlaced parts mentioned above are electrically insulated or electrically conductive. For example, if the shaded area is insulated,
Since the insulating parts 12 and 16 are arranged between 9' and 10' in Fig. 3 and between 14' and 15' in Fig. 4, there is no interspersion between the electrically insulated confounding parts. and Fig. 3 10'
and 1r, and the space between 13' and 14' in FIG. 4 corresponds to the intertwined portions that are electrically conductive. Among all the intertwined parts constituting the knitted fabric per unit area of 1 square inch, the number t of intertwined parts that are electrically insulated and the number t2 of intertwined parts that are electrically conductive. Ratio A, /Z2 is 1/
1 of each prefecture that is on 'JJ'l and that constitutes the knitted fabric.
In unit length per inch, the number of meters between interlaced parts that are electrically insulating among all adjacent interlaced parts,
and the number m2 between interlaced parts that are electrically conductive
When 1/m2 is 179 or more, the tissue is deformed by deformation effects such as elongation and compression, causing thread displacement, twisting, changes in the angle formed by intertwined threads, and changes in contact area.
The intertwined portions and the intertwined portions, which were in an electrically insulating state before deformation, come into contact with the electrically conductive portions, leading to a decrease in the electrical resistance value in the deformation direction, resulting in a knitted fabric having deformation conductivity. The number t of interlaced parts that are electrically insulated and the number t2 of interlaced parts that are electrically conductive, //L
2 is greater than or equal to 1, and the ratio tl11/rn2 of the number m between the interlaced parts that are electrically insulated and the number m2 between the interlaced parts that are electrically conductive is greater than or equal to 1 ha. and,
It is more preferable because the resistance value changes significantly upon deformation. Maku,
When the knitted fabric is in the form of a sheet, the higher the electrically insulating intertwined parts and the Kitamoto between the intertwined parts, the higher the thickness of the sheet becomes a high-density, high-sensitivity pressure-sensitive conductive fabric, which makes it suitable for use as a connector. It is more desirable because it will have the same sex. Further, a cloth having stretch/stick properties by coating or dipping with a resin is more desirable since the repeated durability of the deformation conductivity of the present invention is improved.

The number t of intertwined parts that are electrically insulated among all the intertwined parts constituting the knitted fabric per unit area of 1 square inch
, and the number of electrically conductive parts t2, t, 7t2 is less than 1, or between all adjacent interlaced parts in the unit length per inch of each prefecture constituting the knitted fabric. The ratio of the number m between interlaced parts that are electrically insulating to the number m2 between interlaced parts that are electrically conductive is m1/
If m2 is less than 1, even if tissue deformation occurs, the resistance value in the deformation direction will hardly change, and the resistance value in the deformation direction will hardly change, just in case the number of electrically insulated intertwined parts and intertwined parts is small. Deformed conductive knitted fabrics are no exception.

Next button A method for manufacturing a deformed conductive knitted fabric according to the present invention will be explained.

In other words, it is a knitted fabric made from a conductive yarn that has been coated with a conductive substance by plating, coating, thermal spraying, etc. on electrically insulating fibers, or an electrically insulating knitted fabric is made conductive by plating, coating, thermal spraying, etc. A conductive knitted fabric coated with a substance is prepared. By applying physical stress to this knitted fabric using ultrasonic waves, high-speed jets of water or air, or in a laminar flow medium with a large difference in flow velocity, conductivity is selectively generated between the intertwined parts of the yarns and between the intertwined parts. A deformed conductive knitted fabric is realized for the first time by exfoliating the conductive material.

In this case, it is better to use a highly conductive knitted fabric that is coated with a conductive material by plating, coating, thermal spraying, etc., as the electrically insulating knitted fabric. Since it is applied in a form that covers the intersecting threads, the conductive substance is easily removed by applying physical stress, and a deformable conductive knitted fabric is easily obtained.

In addition, in order to facilitate the separation of the intertwined parts of the conductive substance and between the intertwined parts, fine powder is added before imparting conductivity to the yarn or knitted fabric. It is more effective to relax the weight loss process a little. In addition, if the above-mentioned physical processing is applied to a knitted fabric made using yarn obtained by de-knitting a conductive knitted fabric in which a conductive substance is added to an electrically insulating knitted fabric by the above-described method, it can be easily deformed and made conductive. A knitted fabric is obtained.

<Examples> Examples of modified conductive knitted fabrics according to the present invention will be shown below, and their electrical resistance values will also be compared and shown. It is clear that the modified conductive knitted fabric according to the present invention is not limited to the following examples.

Ester taffeta (Measure 50 [24f) manufactured by Asahi Kahada Kogyo (I)
, latitude 75dA6f) t-sodium hydroxide aqueous solution (sopal), reduced electricity processing at 100℃ (reduced by 1
1g20H), sensitized in a bath with a weight ratio of 5nC22:hydrochloric acid of 3:10, washed with water and dehydrated, activated in a bath with a weight ratio of PdCl2:hydrochloric acid of 1:15, and after washed with water and dehydrated with NiC2.
・6H20, NaHPO2'H20, sodium citrate.

Ni-plated ester taffeta was prepared by treating the sample at 90° C. for 2 minutes in a bath containing NH4C2 and aqueous ammonia in an overlapping ratio of 1:1:3:2:2. This is 1r: 1oc1n x 1oc! r1
Cut the sample into a sample of the size of 100 minutes, 200 minutes, 300 minutes at a speed of 20 Qrpm.

After treatment for 600 minutes, samples &1, 2, and 3.4 of deformed conductive fabrics according to the present invention (products of the present invention) were obtained. Man, 10 minutes.
Samples A5, 6, 7 were processed for 20 minutes, 30 minutes, and 0 minutes.
, 8 comparative examples were obtained. Table 1 shows the change in resistance value due to elongation deformation in the in-plane direction of the present invention and the comparative example. To measure the electrical resistance value by elongation, move the sample 1 in the bias direction.
Cut into 1 f width and 10 cIn length, use 3 cIn scissor electrodes from both ends with two square copper plates of 3 tM on each side, attach it to a tensile tester, and measure the electrical resistance value due to elongation in the bias direction. did. (9) The electrical resistance of the intertwined portion was measured through the intertwined portion of the two intertwined threads using a needle-like electrode with a 10 − tip. in particular,
Using a reflection microscope, while magnifying the intertwined part of a 1 square inch sample, insert a needle between 1 and 2, 3 and 4 in Figure 1, or between 5 and 6, 7 and 8 in Figure 2. The electrical resistance value is measured using a shaped electrode. If the resistance value is 1060 or more, it is determined that it is electrically insulated, and if it is less than 100, it is determined that it is electrically conductive. In addition, the electric resistance value between the intertwined parts can be determined by measuring the electrical resistance between two parts on the opposite side of the intertwined parts using a needle-like electrode using a microscope as in the case of the intertwined parts. Measure below.

As can be seen from Table 1, sample 41, which is the product of the present invention,
In Samples 2, 3, and 4, the electrical resistance value decreases significantly in response to deformation, whereas in Samples A5゜6.7 and 8, which are comparative examples, the resistance value hardly changes or decreases even when deformed. However, it turns out that it is extremely small.

<Effects of the Invention> Since the deformed conductive knitted fabric according to the present invention having the above-described configuration changes its electrical resistance value due to deformation such as elongation or compression, it can be used as a sensor or switch for sensing deformation. For example, it can be used as a flexible sensor adapted to breathing or muscle movements.

Margin below

[Brief explanation of the drawing]

1 and 2 show schematic diagrams of the deformed conductive knitted fabric of the present invention, FIG. 1 showing the deformed conductive plain woven fabric, and FIG. 2 showing the deformed conductive plain knitted fabric. FIG. 3 and FIG. 4 show schematic diagrams of yarns constituting the deformed conductive plain woven fabric and deformed conductive jersey knitted fabric, respectively, which are the products of the present invention. In the figure, the hatched portion means an electrically insulated state, and the white portion means an electrically conductive state. A... Warp, B... Weft, 1, 2, 3, 4
, 5, 6° 7.8... Indicates the parts of the threads that are intertwined with each other, and corresponds to the position where the needle electrode is applied when measuring the electrical resistance value of the intertwined parts, 9.10, 11, 13゜14.15... Intertwined part (part surrounded by dotted line in the figure),
9', 10', 1r, 13', 14
', t r;--opposite side of interlaced part, 12.16
...A part that is electrically insulated between adjacent intertwined parts. $1 Figure 2 Figure 3 Figure 4 Procedural amendment (voluntary) March 9, 1985

Claims (1)

[Scope of Claims] 1. In a deformed conductive knitted fabric whose electrical resistance value changes when stretched or compressed in any direction, electrical conduction occurs in the intertwined portions of yarns constituting the deformed conductive knitted fabric. A modified electrically conductive knitted fabric characterized by its electrical or electrical insulation properties satisfying the following conditions: 1. The number of intertwined parts that are electrically insulated among all the intertwined parts in a predetermined area of the knitted fabric. is l_1, and the number of electrically conductive intertwined parts is l_2, then the ratio l_1/l_
The value of 2 shall be 1/9 or more as measured value per square inch; (2) Electrical If the number of interlaced parts that are insulated is m_1 and the number of interlaced parts that are electrically conductive is m_2, then the ratio m
The value of _1/m_2 shall be 1/9 or more as measured value per inch length.