JPS59190829A - Transparent electrically conductive film - 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] The invention relates to transparent conductive films.

Containers such as bags, trays, tubes, and cases for packaging semiconductor devices, and files and cases for storing and preserving recording materials such as magnetic disks and magnetic cards, have conductive, antistatic, and static electricity properties. Films, sheets, trays, tubes, cases, etc. that have shielding properties are essential, and films, sheets, trays, tubes, cases, etc. used for this purpose are conventionally made of plastics that have been kneaded with a large amount of carbon black. Molded products have been put into practical use, but: 0) They are black and opaque, so if they are used as packaging materials, the contents will not be distinguishable from the outside. Also, since it is only possible to obtain one color, black, it is not possible to classify the color according to the purpose of use.

(Explanation) In order to obtain good conductivity, a large amount of carbon black must be blended, making the molding conditions different, easily damaging the original physical properties of the base material, and further increasing costs.

(c) The sulfur content in carbon black may cause contamination and corrosion of the contents.

- Even if it has the desired electrical conductivity during blow molding, when it is subjected to secondary processing such as roll forming or vacuum forming, the electrical conductivity decreases considerably.

There was a problem.

In addition, conductive molded products made by mixing surfactants into resin and melt-molding them have been known for some time, and although this has the advantage of maintaining the transparency of the molded products, the surfactant gradually disappears. As the surfactant migrates to the surface, the conductivity decreases over a period of six months to a year, the surfactant that migrates to the surface may contaminate the contents, and the ability to remove static electricity is poor under low humidity conditions. It has various disadvantages, such as rapid degradation, which limit its use.

Therefore, the present inventors have conducted repeated research to obtain conductive films using conductive fibers, but depending on the method of blending conductive fibers with thermoplastic resin and melt-molding, During kneading, the conductive F# fibers are cut and the edges and elongation are significantly shortened, and the blended conductive fibers are distributed inside the molded product and the surface of the molded product tends to become a resin layer. Even if a small amount of conductive FII fibers is added, the desired conductivity cannot be obtained, whereas if a large amount of conductive fibers is added, the smoothness of the surface of the molded product will be impaired, making it impossible to obtain a thin film, and increasing costs. (1) Because the conductive fibers are oriented in one direction during extrusion, the physical properties of the resulting molded product in the vertical and horizontal directions are greatly different, and the specific gravity of the conductive fibers is different from that of copper-adsorbing fibers. If a lightweight material is used, problems such as uneven distribution of ψ-heavy fibers in the resulting molded product, resulting in uneven conductivity and uneven mechanical strength, cannot be avoided. Ta.

The present invention fundamentally solves these problems.

The present invention melts and presses a cloth-like material made of conductive fibers (A) and heat-fusible fibers (B) at a temperature higher than the melting temperature of the heat-fusible fibers ω) to form a thin film. A transparent conductor characterized by: a transparent film.

The present invention provides excellent effects as listed below.

(a,) The conductive film of the present invention has excellent conductivity, antistatic properties, and static electricity shielding properties. ('b) Since it is transparent, it can be used in bags or molded products made from this conductive film. The filled contents can be visually confirmed. It is also possible to make it transparent and colored depending on the purpose of use.

(0) Thin films can also be easily obtained.

(d.) The conductive fibers in the film can be arranged in either a random arrangement or a regular arrangement, and the density of the arrangement can be adjusted as desired.

(e) The fiber length of the conductive Pl string used as a raw material is maintained at 1 even in the product film.

(f) Although the conductive fibers are exposed on the surface of the product film, the surface of the product film is smooth and smooth.

Even if a material with a low specific gravity such as copper adsorption fiber is used as the soft conductive and conductive fiber, a product film with uniformity in both conductivity and mechanical strength can be obtained.

Ql) The conductivity of the obtained film is semi-permanent, and there is no decrease in conductivity due to humidity or change over time.

(i) Even when used as packaging material, it does not cause contamination or corrosion of the contents.

(j) Roll forming this conductive film,
Even when subjected to secondary processing such as vacuum forming, the conductivity does not decrease at all.

(Ko) This conductive film can be used by itself as a film, bag, file, etc. for packaging and storing semiconductor devices, recording materials, etc., and if it is attached to other substrates, it can be used as It is possible to impart excellent conductivity, antistatic properties, static electricity shielding properties, and flake adhesion prevention properties to the base material without significantly impairing its transparency or coloring.

Examples of the conductive U' group (A) in the present invention include copper adsorption grade kasuri, gold-plated fibers, carbon fibers, carbon composite cords, metal steamer fibers, thin metal wires, and the like. Here tl+
The 'i-adsorbed cotton fiber' is obtained by adsorbing copper ions to a cyan group-containing cord and then reducing it. Among these, copper-adsorbed resin has the optimum surface resistance value of 10 to 10 Ω, especially 10 to 0 Ω, is light and flexible, has excellent bending resistance, and can be dyed in any color. It is particularly preferable because it is easy to use, is inexpensive, and does not have antibacterial or deodorizing properties.

In addition, heat-melting fibers (■) include polyolefin fibers [a, nylon #v fibers, polyester delicate fibers, acrylic fibers f]
In this case, a divine fiber made of ethylene-vinyl alcohol copolymer system is used. A composite fiber containing a resin that can be melted by heating as one component can also be used as the heat-melting fiber.

The cloth-like material is composed of the above-mentioned conductive embroidery # (A) and the heat-melting fiber (B), and the cloth-like material here refers to nonwoven fabrics, woven fabrics, knitted fabrics, and similar materials. It is created as follows.

A. Obtain a nonwoven fabric f from the mixed warp fibers of (A) and (B) by a conventional method.

Fiber making using either a spun yarn containing at least a portion of (5), a filament yarn of (A), or a twisted yarn consisting of (A) and (A)) as at least a portion of the warp or weft. A woven fabric consisting of the material and (B) is obtained.

(A) and (I3)
A knitted fabric is obtained.

For practical use, non-woven fabrics are particularly suitable for shoulder wear. In this case, as the fiber material, the conductive #& fiber (A) and the heat-melting fiber (I3) have a thickness of 1 to 50 tenier and a length of 10 to 10
It is preferred to use fibers with a diameter of 0.

In addition to the above fiber ion materials (A) and (B), the cloth-like material may contain other high melting point fibers or non-melting fibers (
C) may be included.

The ratio of conductive fibers, Ia (A) and heat-fusible fibers) in the cloth-like material is, for example, 0.1 to 50% by weight of (A), [
F]) can be selected from the range of 99.9 to 50% by weight, and particularly preferably selected from the ranges of (3) 1 to 30% by weight and (B) 99 to 70% by weight. If the ratio of 03) is too small, it will not be possible to obtain a conductive film, while if the ratio of 03) is too small, it will be difficult to form the film itself. When other fibers with a high melting point or fibers (C) that do not show melting properties are used together, the total amount of (A) and (B) is 70 weight percent or more out of 100 weight percent of the total fiber material. It is desirable that (C) be the remainder. If the proportion of other fibers (C) becomes too large, the relative
This is because the ratio of 0 to 10% decreases, making it difficult to form a film.

The desired transparent conductive film is obtained by supplying the cloth-like material to a heating and pressing step, and melting and pressing the material at a temperature higher than that at which the hot-melt fiber (B) melts. It will be done.

This melting and suppression is performed, for example, by passing the cloth-like material between heated rolls or by interposing the cloth-like material between hot plates and pressing it.

The pressure can vary widely, but is often selected from the range of 5 to 30 kV. The cloth-like material may be melted and compressed in the form of a single layer (one sheet), but a plurality of cloth-like materials may be stacked in any direction and subjected to melting and compression.

By melting and pressing, the cloth-like material changes into a thin film, and a transparent conductive film is obtained. The conductivity of this film varies depending on the type and amount of conductive fiber used, but the surface resistance value is 10 to 10 8 Ω·-. Especially 10-10
It is preferable to select conditions so that Ω·-. Although the transparency of the film also varies depending on the type of fiber material used and the thickness of the resulting film, it is preferable to select conditions such that the light transmittance is 50% or more.

The thickness of the film ranges from a thin film of about 10 microns to several tens of microns.
It can be made into any thickness up to a 0μ sheet.

The resulting film will be smooth and generally non-porous, but if desired, it can be made perforated by using an open cloth.

If the obtained film is subjected to secondary processing such as vacuum forming or roll forming, it can be made into trays, containers, magazine rails, etc.
A carrier tape etc. can be obtained. Note that if the cloth-like material is directly subjected to a vacuum forming machine, trays, containers, etc. can be obtained all at once by applying heat and pressure in the vacuum forming process.

The obtained film can also be applied to other substrates, such as plastic films, sheets, plates, tubes, containers, parts, gear vignettes, etc., rubber, inorganic materials, instrument windows, cathode ray tubes, indoor walls, textiles, etc. If the thermoplastic resin used as the base material is integrated into the film by layer-by-layer wrapping, melt extrusion or injection, the transparency and coloring of these base materials will be significantly impaired. It is possible to impart excellent conductivity, antistatic properties, and static electricity shielding properties without causing any damage.

The transparent conductive film of the present invention or its processed products, laminated with other substrates, and wrapped products can be used, for example, as materials for packaging, storing, and transporting semiconductor devices (films, sheets, containers, trays, bags, tubes, magazines, etc.). (rails, cases, etc.), files and case materials for storing and preserving recording charges such as magnetic disks and magnetic cards, VTR tapes, parts, cabinets, and housings for other electronic and electrical equipment, packaging materials for precision equipment, and computers. Related equipment, storage, and packaging materials, various materials and interior materials used in clean rooms, sterile rooms, hospitals, etc., physique of departments that handle solvents, dust, gunpowder, and explosives, automobile, aircraft, and ship-related materials, and dust adsorption. It is useful for applications such as sterile packaging materials, packaging materials for medical disposable equipment, materials for air transportation, electromagnetic shielding materials, and labeling materials.

Next, the present invention will be further explained with reference to Examples.

Example 1 Acrylic-based preparation π? having a thickness of 2 to 3 deniers and a length of 501111111. Embroidery M (Thunderon, manufactured by Nippon Kasuke Dyeing Co., Ltd.) (A) Ion content%, thickness 2-3 denier, length 50 mm polyester fiber (melting point 140°C)
A nonwoven fabric having a weight of 100 I consisting of 90% by weight of ) was supplied to three pairs of rolls, and heated and pressed to obtain a film. The temperature and pressure of the rolls are 150°C and 20k for the first pair.
g/cnl, next pair is 170°C 110 pieces, last one
The pair is 160°C5i o kg/co! It was set to

The film obtained by passing through the roll group has a thickness of 80 μm, has a smooth surface and is non-porous, and has a coating of I#,
Although the presence of a random network of fibers (3) was discernible, the transparency was favorable at 70% in terms of light transmittance.

The discharge half-life of this film using a static honest meter was only 1 second when measured under dry conditions at 20°C and 140% RH. (Incidentally, the discharge half-life of polyester film is 102 seconds or more.) Furthermore, when the surface resistance value of the film was measured by applying the surface terminal f of a tester to two arbitrary points on the surface of the film, it showed the optimum conductivity and property of 10 Ω·-.

The strength is 2500 kg/ad in the vertical direction and 2 in the horizontal direction.
000 kg/ad.

Next, this film was attached to a polyethylene film using an adhesive, and then a bag was made with the attached side facing inside. This bag has excellent antistatic and static shielding properties, and
Since the contents can be seen through, it is useful as a bag for packaging semiconductor devices or storing magnetic disks.

Further, the above film was attached to a hard polyvinyl chloride sheet using an adhesive, and then roll-forming was performed so that the attached surface was on the inside to create a magazine rail with a substantially concave cross section.

This magazine rail is suitable for storing and transporting semiconductor devices.

Example 2 Cyano yarn introduced with a thickness of 2 to 3 deniers and a length of 50 KII11 Nylon-based preparation NO/fiber (A) 5% by weight and thickness of 2 to 3
3 denier, 50mm long nylon fiber (melting point 130°)
C) (B) Weight 120 g/95% by weight
rr? The nonwoven fabric was sandwiched between two ferrotype plates and fed into a compression molding machine, and the hot plate temperature was 140'C and the pressure was 15 kV.
Hot pressure was applied for 30 seconds under the following conditions, and then the pressure was released and allowed to cool.

The obtained film has a thickness of 100μ, and the surface is smooth and non-porous, and although the presence of random networks of the pre-coated fibers (8) can be discerned, the transparency is poor in terms of light transmittance. It was 50%, which was preferable. The discharge half-life of this film was 1 second when measured at 20°C and 140RH, and the surface resistance was 10 Ω・d.The strength was 2 s o kg/a+I in the longitudinal direction. , and the transverse direction was 2000 kg/ad.

Example 3 Acrylic copper fall coat grade (A) 2-3 denier thickness, 50 mm length, 2-3 denier thickness, 50 mm length, m (M point 1 as °C) (B) 8s weight%, thickness 2-3 denier, length 5
Acrylic fiber marked 0 (high melting point) (C) I
Weight consisting of OM amount% s o gAr? This is what I put together two pieces of non-woven fabric. Sandwiched between two ferrotype plates and fed to a compression molding machine, heated plate temperature 140°C 1 pressure], OK
Hot pressing was performed under V- conditions.

The properties and characteristics of the obtained film were as follows.

Thickness: 60μ Properties: Smooth, non-porous Transparency: Light transmittance 80% Strength: 1400 klcml in the vertical direction, 1200 klcml in the horizontal direction
- Discharge half-life: 10 seconds (20°C, 40% RH) Surface resistance: 104 to 5 Ω・d Example 4 Canted acrylic prepared binding #2 weight%, nylon fiber (melting point 1.20 (B) 80% by weight of nylon fibers (with high melting point) (C) 18% by weight of nylon fibers (C) with a weight of 100 g/m' The woven fabric was heated and pressed between heated rolls at a temperature of 150°C.

As a result, a film having the following properties and characteristics was obtained.

Thickness: 80μ Properties: Smooth, non-porous Transparency: Light transmittance 60% (However, the regular mesh in C) can be identified) Strength: 4000 kF￥oI in the vertical direction, 3000 kF in the horizontal direction
kg/cnl Discharge half-life: 10' seconds (20°C 140%RH) Surface resistance value: 105-6Ω・d Example 5 Long fibers of nylon-based prepared fastened fibers introduced with cyan thread of 2 denier thickness (A) and 3 denier nylon fiber (melting point 1
A knitted fabric with a weight of 80 g/rrr was prepared by knitting yarns bundled at a ratio of 30° C.) and 1:3.

This knitted fabric was passed through a tube between heated rolls at a temperature of 160°C and hot-pressed. As a result, a film having the following properties and characteristics was obtained.

Thickness: 260μ Properties: Smooth, perforated Transparency - Light transmittance 70% (regular network can be discerned) Discharge half-life = 10 seconds Surface resistance value = 104~5Ω・d Example 6 Cyan group A knitted fabric was obtained in the same manner as in Example 5, except that nickel-plated fiber #(A) was used in place of introduced nylon-based prepared fiber #, and a film was further produced. The surface resistance value of the obtained perforated film was 10 Ω·d The light transmittance of the portion other than the 1 hole was 60%.

Patent applicant: Fujimori Industries Co., Ltd.

Claims (1)

[Claims] 1. A state in which a cloth-like material consisting of a conductive edge #(A) and heat-fusible tP fibers (g)) is heated to a temperature higher than that at which the heat-fusible fibers (B) melt. 2. The conductive film according to claim 1, wherein the transparent conductive film 0 2 is formed into a thin film by melting and pressing. 3. The conductive film according to claim 1, wherein the film has a light transmittance of 50% or more. 4. The conductive material according to claim 1, wherein the cloth-like material is a cloth-like material consisting of 1 to 30% by weight of conductive fibers (A) and 99 to 70% by weight of heat-fusible fibers (B). film. 5. The conductive film according to claim 1, wherein the cloth-like material is a nonwoven fabric, a woven fabric, or a knitted fabric.