JP2009218683A - Sheet structured material for communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the flexible sheet structured material can maintain proper communication performance, without occurrence of folded-up creases, even when the sheet is bent or rolled up. <P>SOLUTION: The sheet structured material for communication includes at least three layers (an upper layer, a middle layer and a lower layer), wherein each of the layers is sutured by thread. The upper layer has conductive ability and includes an electrically conducting portion and a non-electrically conducting portion. The percentage of the electric conduction portion is 8% to 45%, and the electric conduction portion continues, without completely breaking off, and the electrical resistance value of the electrically conducting portion is 5 Ω/square or smaller. The intermediate layer has a dielectric dissipation factor of in the frequency range at 800 MHz to 10 GHz of 0.01 or smaller. The lower layer has electrical conductivity for the entire surface and has an electrical resistance value of 1 Ω/square or smaller. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a communication sheet structure having a two-dimensional expanse, and when an information communication device is in contact with or close to the surface thereof, communication with the communication device or a plurality of information communication devices is performed. The present invention relates to a flexible communication sheet structure (hereinafter referred to as “communication sheet structure”) that is optimal for relaying communication between devices when they are in contact with or close to the surface.

In recent years, the use of computer communication networks and information networks represented by the Internet has become widespread and generalized regardless of general households and companies. The most common usage is to connect a LAN cable directly to a personal computer, etc.
An area network is formed, and a computer in the LAN can access a network such as the Internet. Under such circumstances, when a LAN cable is used, the cable is routed in a house or office, which may hinder walking or cause an aesthetic problem. In addition, when a wireless LAN is used, communication is performed using radio wave radiation, which causes security problems such as information leakage and unauthorized access.

Therefore, it is possible to solve these problems by using a planar communication medium capable of confining signals in two dimensions. Patent Document 1 (Japanese Patent Laid-Open No. 2004-7448) and Patent Document 2 (Japanese Patent Laid-Open No. 2006-19979). Gazette).
It is considered to use a two-dimensional communication medium for physical distribution management and office security management, and it is desired to be easy to carry. However, the communication medium described in the prior art has no flexibility, and there is a problem that wrinkles are generated when the sheet is bent or rolled.
On the other hand, in recent years, research on wearable computers worn like clothes, bags, and watches has been actively conducted. Since the flexible sheet structure according to the present invention is flexible and does not peel even when the sheet is bent or rolled, it can be used for a wearable computer.
JP 2004-7448 A JP 2006-19979 A

  An object of the present invention is to provide a flexible sheet structure capable of maintaining excellent communication performance without causing wrinkles even when the sheet is bent or rolled.

As a result of studies to solve the above problems, the present inventors have found that the following communication sheet can solve the problem.
Thus, according to the present invention, there is provided a communication sheet structure comprising a sheet structure composed of at least the following three layers of the upper layer, the middle layer and the lower layer, each layer being sewn with a thread.
Upper layer: a layer having conductive performance, where the conductive portion and the non-conductive portion are present in the layer, the proportion of the conductive portion is 8% to 45%, and the conductive portion is continuous without any interruption. Layer with electrical resistance of 5 Ω / □ or less Middle layer: Layer with dielectric loss tangent of 0.01 or less at a frequency of 800 MHz to 10 GHz Lower layer: Conductivity on the entire surface, with electrical resistance of 1 Ω / □ or less A layer

  By using the communication flexible sheet structure of the present invention, excellent communication performance can be maintained without generating wrinkles even when the sheet is bent or rolled. Furthermore, it can be expected to be applied to wearable computers.

Hereinafter, the present invention will be described in detail.
In consideration of the fact that the communication sheet structure of the present invention must maintain excellent communication performance without causing wrinkles even when the sheet is bent or rolled, a three-layer fabric is sewn with a thread. It is preferable to make them.

  Next, the communication sheet structure of the present invention comprises at least three layers: an upper layer, a middle layer, and a lower layer. In order to perform two-dimensional communication, electromagnetic energy must be confined in the sheet medium and utilized using this sheet configuration. If the sheet configuration is different, electromagnetic energy cannot be confined in the sheet medium, and excellent communication performance cannot be maintained.

Upper layer:
Regarding the conductivity of the upper layer, the conductive portion and the non-conductive portion are present in the layer, and the conductive portion area should be continuous from 8% to 45% without being completely interrupted. If the proportion of the conductive part in the layer is less than 8%, the electromagnetic energy is lost and a good communication state cannot be maintained. On the other hand, if the proportion of the conductive portion exceeds 45%, the evanescent wave serving as an electric signal medium does not ooze out from the sheet, so that a good communication state cannot be maintained. The electrical resistance value of the conductive part also greatly affects the communication performance, and the lower the electrical resistance value, the better the communication state can be maintained. If the electric resistance value of the conductive portion is 5Ω / □ or less, a good communication state can be maintained. However, when the electrical resistance value of the upper conductive portion exceeds 5Ω / □, electromagnetic energy cannot be propagated and contained in the sheet, and two-dimensional communication cannot be performed. Here, in order to make the electric resistance value of the conductive portion 5Ω / □ or less, it is preferable to use a material containing copper, silver, aluminum, and stainless steel.
The electric resistance value of the conductive part is preferably 0.001Ω / □ to 3Ω / □.

  The upper layer base material is preferably a fabric. In addition, as materials, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT) and other polyesters, nylon 6, nylon 66, nylon 12 and other aliphatic polyamides And a cloth made of fibers such as aromatic polyamide such as polyparaphenylene terephthalamide and polymetaphenylene terephthalamide, polypropylene (PP), polyethylene (PE), polycarbonate (PC) and polyimide (PI). Examples of the fabric mentioned here include woven fabrics, knitted fabrics and non-woven fabrics, with woven fabrics being particularly preferred. Any woven fabric may be used as long as it is flexible, but a woven fabric having a fineness of 30 to 1,500 dtex and a woven fabric density of 15 to 200 / inch is preferable. Moreover, in order to make it easy to print the conductive paste on the fabric, the surface of the fabric is preferably coated with a resin.

  In order to impart the conductive performance to the upper layer, a conductive material may be used, and a material containing a metal such as copper, silver, aluminum, or nickel is particularly preferable. As a method for imparting conductive performance, it is preferable to screen-print a paste resin containing a conductive material on the fabric surface. The conductive shape of the upper layer is not particularly limited, but when considering the workability at the time of manufacturing the communication sheet structure, it is preferably the lattice shape shown in FIG. 1 or the honeycomb shape shown in FIG. Among them, it is particularly preferable that the lattice shape is 0.5 to 1.5 mm and the interval between the lattice lines is 5 to 10 mm.

The thickness of the upper layer is usually 0.02 mm to 5 mm, preferably 0.05 mm to 0.6 mm.
The basis weight of the upper layer is usually 50 g / m ² to 800 g / m ² , preferably 100 g / m ² to 250 g / m ² .

Middle layer:
The middle layer of the present invention may be a fiber structure (woven fabric, knitted fabric, non-woven fabric) having a dielectric loss tangent of 0.01 or less at 800 MHz to 10 GHz. Communication state can be maintained. However, if the dielectric loss tangent from 800 MHz to 10 GHz exceeds 0.01, electromagnetic energy cannot be contained in the sheet, resulting in energy loss. As a result, the communication performance tends to be greatly reduced.
Here, in order to make the dielectric loss tangent 0.01 or less, it is preferable to use a fiber structure having an air layer. The dielectric loss tangent is preferably 0.01 or less.
The middle layer preferably has a thickness of 0.02 mm to 10 mm, preferably 0.5 mm to 2.0 mm.
The basis weight of the middle layer is preferably 50 g / m ² to 800 g / m ² , more preferably 80 g / m ² to 300 g / m ² .

Underlayer:
If the lower layer has conductivity on the entire surface, that is, if it has electromagnetic wave shielding performance on the entire surface, a good communication state can be maintained. The electrical resistance value may be 1Ω / □ or less. However, if the lower layer does not have conductivity on the entire surface, for example, if there is an insulating part in one part or if the electrical resistance exceeds 1Ω / □, electromagnetic energy will leak from that part. End up. For this reason, electromagnetic energy cannot be contained in the sheet, energy loss occurs, and communication performance is greatly reduced.
Here, in order to reduce the electrical resistance value to 1Ω / □ or less, when considering the workability at the time of manufacturing the communication sheet structure, a fabric in which copper, nickel, etc. are plated on the fiber fabric, or copper, silver on the film surface A film-like material in which aluminum or the like is vapor-deposited, or a metal foil such as a copper foil or an aluminum foil is preferable. By using these, a good communication state can be maintained.
The electric resistance value is preferably 0.8Ω / □ or less.
Examples of the fabric mentioned here include woven fabrics, knitted fabrics and non-woven fabrics, with woven fabrics being particularly preferred. The fineness of the fabric is preferably 30 to 1500 dtex, and the fabric density is 15 to 200 / inch.
In addition, the thickness of a lower layer is 0.02 mm to 5 mm normally, Preferably it is 0.1 mm to 0.4 mm.
The basis weight of the lower layer is usually 50 g / m ² to 800 g / m ² , preferably 80 g / m ² to 200 g / m ² .

The lower layer is not particularly limited as long as the electrical resistance value is 1 Ω / □ or less per 1 m ² and the entire surface has electromagnetic wave shielding performance. As described above, when considering the workability at the time of sheet manufacture and the thickness of the sheet structure, a fabric in which the fabric is plated with copper or nickel on the fiber fabric, or a film in which copper, silver, aluminum or the like is evaporated on the film surface And metal foils such as copper foil and aluminum foil are preferable, and a good communication state can be maintained by using these.

It is important that the communication sheet structure of the present invention is obtained by stitching the upper layer, middle layer and lower layer with a thread. With such a configuration, even when the communication sheet structure is bent or rounded, the communication performance can be maintained without causing wrinkles. When the communication sheet structure is within 100 cm square, it is only necessary to sew the periphery of the fabric with a thread. In the case of a size larger than the above, when pressed with a stitch of about 5 cm square to 15 cm square and subjected to quilting, the appearance is good, and creases are less likely to occur.
A commercially available thread can be used as the thread to be sewn, and a spun sewing thread or a filament sewing machine may be used, but a spun yarn of 30 to 80th of the spun sewing thread is preferable. The stitches may be hand-sewn or sewing.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the physical property in an Example and a comparative example was measured with the following method.

Electrical resistance value:
The electrical resistance values of the upper layer and the lower layer were measured using “Loresta MP MCP-T350” manufactured by Mitsubishi Chemical.

Communication performance evaluation judgment:
As shown in FIG. 3, two proximity connectors placed on the communication sheet structure are arranged apart by a distance r, and a transmission coefficient X at 2.45 GHz is measured using a network analyzer manufactured by Agilent. To do. Here, the distance between the proximity connectors was 1 cm, and measurement was performed from 10 cm to 80 cm. The proximity connector used was a communication sheet structure having a peak at 2.45 GHz. The average value (Xav.) Of the measured transmission coefficient X was calculated. Xav. If it was ≧ −30 dB, it was judged as acceptable, and otherwise it was judged as unacceptable.

Bending durability evaluation judgment / folding wrinkle evaluation judgment:
Using Teijin's “Bending Fatigue Testing Machine”, the state change after bending and deforming 30 times was observed. Further, the electromagnetic wave shielding property Y at 1.0 GHz is measured using a spectrum analyzer with a tracking generator (R3361A; manufactured by Advantest). The difference (ΔY) between the electromagnetic wave shielding property (Yb) before bending and the electromagnetic wave shielding property (Ya) after bending was calculated, and if ΔY ≦ 10 dB, it was judged as acceptable, and otherwise it was regarded as unacceptable. Furthermore, the folding wrinkle after bending and deforming 30 times was visually determined. If wrinkles could not be confirmed and it was the same as before bending deformation, it was accepted, and if wrinkles could be confirmed and it was clearly different from the state before bending deformation, it was rejected.

Example 1
In the upper layer, a silver paste is printed in a lattice shape with a line width of 1.4 mm and a line cycle of 5 mm on a PET fabric (“New Shelf II” manufactured by Kawashima Textile Cellcon Co., Ltd.) obtained by laminating a PET fabric with urethane resin. An m ² PET fabric was obtained. The thickness 2mm is the middle layer, fineness 18Dtex, PET nonwoven fabric of basis weight 110g / ^{m 2} (Teijin needle punched nonwoven fabric), the lower layer was plated with copper and nickel PET fabric fineness 57Dtex, electromagnetic waves having a basis weight of 85 g / ^{m 2} A shield fabric (“ST2050” manufactured by Teijin Fibers Limited) was used. These were bonded together by sewing using a polyester sewing thread (60th, manufactured by Teijin Fibers Limited). Sewing was performed using a JUKI DDL-5530 lockstitch machine base and sewing needle DB × 1 # 14 with a stitch length of 3 cm / 13 stitches. The electric resistance value of the upper conductive portion was 0.3 Ω / □ per 1 m ² , the dielectric loss tangent of the middle layer was 0.01, and the electric resistance value of the lower layer was 0.03 Ω / □. The results are shown in Table 1.

Example 2
The upper layer is a polyethylene terephthalate (PET) woven fabric with a basis weight of 200 g / m ^{2 in} which stainless fibers are woven in a lattice pattern, the middle layer is a PET nonwoven fabric (needle punch nonwoven fabric manufactured by Otsuka) with a thickness of 1 mm and a basis weight of 110 g / m ² , and the lower layer Used was an electromagnetic wave shielding fabric (“ST2050” manufactured by Teijin Fibers Ltd.) having a basis weight of 85 g / m ² , in which copper and nickel were plated on a PET fabric. The lattice shape of the upper layer has a line width of 1.3 mm, a line interval of 8 mm, and a conductive portion ratio of 13%. These were sewn in the same manner as in the examples. The electric resistance value of the upper conductive portion was 1Ω / □, the dielectric loss tangent of the middle layer was 0.01, and the electric resistance value of the lower layer was 0.03Ω / □. The stainless steel fiber used for the upper layer fabric is manufactured by Bekato Tozuna Metal Fiber Co., Ltd., with a fineness of 2,200 dtex, and the PET fiber is “Tetron” manufactured by Teijin Fibers Ltd., with a fineness of 280 dtex. After that, two stainless fibers were repeated for every 14 PET fibers, and two stainless fibers were repeated for every 12 PET fibers. The upper layer was the same as in Example 1 except that the upper layer was replaced with a PET fabric woven with stainless steel fibers. The results are shown in Table 1.

Comparative Example 1
The structure of the three layers is the same as in Example 1, and a communication sheet structure is formed by pressure bonding with a hot press using PET hot melt at 100 ° C. and 1.0 kg / m ³ for 10 seconds using a press machine and bonding. The body was made. The results are shown in Table 1.

Comparative Example 2
The structure of the three layers is the same as in Example 1, and an acrylic adhesive (“Dai Nippon Ink Chemical Co., Ltd.“ Quickmaster SPS-945T ”, the same applies hereinafter) is applied to the table coater so that the adhesion amount is 10 g / m ^{2 on} each side. Was applied. Thereafter, the upper layer and the middle layer were adhered by a calendering machine, and finally the lower layer was adhered by a calendering machine to produce a communication sheet structure. The results are shown in Table 1.

Bending durability evaluation / folding wrinkle evaluation:
○ ・ ・ ・ No wrinkles × ・ ・ ・ Fold wrinkles

  The communication sheet structure of the present invention is capable of two-dimensional communication in a frequency band of 800 MHz to 10 GHz, and is useful as a product for carrying and using the sheet structure. There is also a great potential for use as a wearable computer.

1 is a front view of an upper layer of a communication sheet structure in one embodiment of the present invention. It is another embodiment of this invention, and is a front view of the sheet | seat structure upper layer for communication. It is a front view of the upper layer of the communication sheet structure for the communication performance evaluation method of the present invention.

Claims (3)

A communication sheet structure comprising a sheet structure composed of at least the following three layers of an upper layer, a middle layer and a lower layer, wherein each layer is sewn with a thread.
Upper layer: a layer having conductive performance, where the conductive portion and the non-conductive portion are present in the layer, the proportion of the conductive portion is 8% to 45%, and the conductive portion is continuous without any interruption. Layer with electrical resistance of 5 Ω / □ or less Middle layer: Layer with dielectric loss tangent of 0.01 or less at a frequency of 800 MHz to 10 GHz Lower layer: Conductivity on the entire surface, with electrical resistance of 1 Ω / □ or less A layer   The communication sheet structure according to claim 1, wherein each layer is a layer based on a woven fabric, a knitted fabric, or a nonwoven fabric.   The communication sheet structure according to claim 1, wherein the upper conductive portion has a lattice shape, the line width of the lattice is 0.5 mm to 1.5 mm, and the line interval is 5 mm to 10 mm.

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