JPH0642159U - Conductive sheet - Google Patents

Abstract

(57) [Summary] [Purpose] Both the front and back sides can be colored in a color other than black, which is excellent in design, there is no migration of antistatic agents, there is no floating of conductive material, pollution is prevented, and resistance values on the front and back are the same. Provide low resistance. [Structure] Conductivity having a volume resistance of 10 ² to 10 ⁵ between front and back double-sided layers A and C made of a colored antistatic thermoplastic synthetic resin sheet having a volume resistance of 10 ⁸ to 10 ¹¹ Ω. The intermediate layer B made of a thermoplastic thermoplastic resin sheet is laminated to form a three-layer structure, and the volume resistance of this laminated body is 10 ⁵
Conductive sheet with a value of -10 ⁸ Ω.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention can be applied to a place where electronic parts such as a semiconductor manufacturing factory, a precision machine manufacturing factory, and an electric parts manufacturing factory are used, or a place where a precision instrument using a computer is used, such as a hospital or a laboratory, to prevent malfunctions and failures due to static electricity. Therefore, it relates to a conductive sheet used for laying under equipment to cover these equipment, covering equipment, etc.

[0002]

[Prior art]

 Conventionally, in places where electronic parts such as semiconductor manufacturing factories, precision machinery manufacturing factories, electric component manufacturing factories, etc. are used and where precision equipment using computers is used, such as hospitals and laboratories, there is a risk of electrostatic damage and disasters. In order to protect the product from heat and to prevent malfunction of precision equipment due to static electricity, a conductive material containing thermoplastic resin mixed with conductive carbon black, conductive carbon fiber, conductive metal powder, conductive metal fiber, etc. A single layer product of a heat resistant thermoplastic resin sheet or an antistatic thermoplastic synthetic resin sheet containing a large amount of an antistatic agent added thereto and a two-layer laminated structure product thereof have been used.

[0003]

[Problems to be solved by the device]

 A sheet containing conductive carbon black has the advantage of being able to set a relatively low volume resistance value at low cost, but since the surface is limited to black, the working environment at the place of use deteriorates, and a large amount of conductive material is added. Since carbon black is added, it is vulnerable to abrasion, and carbon particles are easily removed from the surface, which is not preferable because it becomes a pollutant in the above work place.

Further, the conductive thermoplastic sheet containing the conductive carbon fiber, the conductive metal powder, and the conductive metal fiber can be colored relatively and the workability is improved, but the fibers and the metal particles are easily removed from the surface. Similarly, it becomes a pollutant, which is not preferable.

The sheet to which the antistatic agent is added can be colored, but it is difficult to obtain the performance having a volume resistance of 10 ⁸ Ω or less. Therefore, a large amount of the antistatic agent is added to increase the thickness of the sheet. The thickness of the sheet must be increased, and the thicker the sheet, the higher the concentration of the antistatic agent per area, and this tends to migrate to the surface, which is not preferable because it contaminates these devices.

Further, even in the case of the above-mentioned two-layer laminated structure product of the antistatic sheet layer and the conductive sheet layer, the conductive fibers and particles of the conductive sheet layer are detached and suspended, which is not preferable because it becomes a pollutant.

Therefore, it is possible to color other than black and has excellent designability, there is no contamination due to migration of antistatic agents and contamination due to floating of conductive fibers or particles, the resistance values of the front and back are the same, and the volume resistance is low. A conductive sheet has been desired.

[0008]

[Means for Solving the Problems]

 The present invention is a multi-layered body composed of a conductive sheet having a low electric resistance value and an antistatic sheet having a coloring property and having a higher electric resistance value than the conductive sheet. It is intended to solve the above problems and provide a conductive sheet having excellent electric performance and design by using a three-layer structure in which preventive sheets are laminated.

The means has a volume resistance of 10 when an antistatic agent and an antistatic plasticizer are added.⁸-10 ¹¹ The volume resistance obtained by adding conductive carbon black, conductive carbon fiber, conductive metal powder, conductive metal fiber, etc. between the front and back surfaces made of a colored antistatic thermoplastic synthetic resin sheet having a value of Ω is 10²-10^FiveA conductive thermoplastic synthetic resin sheet having a value of Ω is laminated as an intermediate layer, and the volume resistance of this laminated body is 10^Five-10⁸It is a conductive sheet with a value of Ω and features a structure that can obtain the same electrical performance from both the front and back.

[0010]

Embodiment An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross-sectional structure of a conductive sheet of the present invention, where A and C are surfaces made of a colored antistatic thermoplastic resin sheet obtained by adding an antistatic agent and an antistatic plasticizer. Layers and a back surface layer, and B represents an intermediate layer made of a conductive thermoplastic resin sheet to which carbon black or the like is added.

Both front and back layers made of a colored antistatic thermoplastic synthetic resin sheet are vinyl chloride resins such as vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-urethane copolymer resin, polyethylene, polypropylene, ethylene- A vinyl acetate copolymer resin, an olefin resin such as ethylene-acrylate copolymer resin, or a thermoplastic synthetic resin such as urethane resin, particularly preferably a vinyl chloride resin, which has a volume resistance to these synthetic resins. To obtain a value of 10 ⁸ to 10 ¹¹ Ω, a nonionic or cationic antistatic agent, dibutoxyethyl phthalate, butyl diglycol adipate, Placizer M-300L (Kyowa Hakko), AM903B (Sekisui Chemical Co., Ltd.) Antistatic plasticizer such as dioctyl phthalate A sheet having a thickness of 0.1 to 1 mm is formed by adding a plasticizer, a stabilizer, a coloring agent and the like, and carrying out calender molding, extrusion molding and the like.

The intermediate layer made of a conductive thermoplastic synthetic resin sheet is made of carbon, nickel, stainless, aluminum or the like so that the volume resistance of the thermoplastic synthetic resin is 10 ² to 10 ⁵ Ω. Powder or short fiber, or conductive material such as inorganic particles surface-treated with tin oxide, zinc oxide, nickel, etc., alone or in combination of 5 to 50% of two or more kinds, and a general-purpose plasticizer, stabilizer, etc. It was added and similarly made into a sheet with a thickness of 0.1 to 1 mm.

An antistatic sheet having the above-mentioned antistatic agent and antistatic plasticizer added to both sides of this conductive sheet is heated at a temperature of 180 to 200 ° C. and pressure-bonded to be laminated and integrated.

Next, a specific embodiment of the present invention will be described.

【Example】

 Formulation Example 1 Vinyl chloride resin (Nipolit SL) 100 parts by weight Dioctyl phthalate 25 parts by weight Dibutoxyethyl phthalate 20 parts by weight Barium stearate 1.5 parts by weight Zinc stearate 1.5 parts by weight Polyoxyethylene alkyl ether 1.0 parts by weight Part calcium carbonate 20 parts by weight

The vinyl chloride compound having the above composition is mixed and stirred in a Henschel mixer at room temperature for 30 seconds. When sufficiently mixed, 1 part by weight of titanium oxide and 3 parts by weight of phthalocyanine blue are added as colorants and heated to 150 ° C. Knead for 1 minute in a warm Banbury mixer to gel the compound. The compound was rolled into a blue sheet having a thickness of 0.45 mm using a calendering machine adjusted to a temperature of 180 ° C.

Formulation Example 2 Vinyl chloride resin (Nipolite SL) 100 parts by weight Dioctyl phthalate 60 parts by weight Lead stearate 2.0 parts by weight Barium stearate 0.5 parts by weight Dibasic lead stearate 0.3 parts by weight Ketjen Black 30 parts by weight Calcium carbonate 20 parts by weight

The vinyl chloride compound having the above composition is mixed and stirred in a Henschel mixer at room temperature for 30 seconds, and when sufficiently mixed, it is kneaded in a Banbury mixer heated to 150 ° C. for 2 minutes to gel the compound. .

The compound was rolled into a black sheet having a thickness of 0.40 mm with a calendering machine adjusted to a temperature of 180 ° C.

Using the black conductive sheet obtained in Formulation Example 2 as an intermediate layer, the blue antistatic coloring sheet of Formulation Example 1 was heated and laminated vertically, and the black conductive sheet was laminated in the middle. A 3 mm blue conductive sheet was obtained. Regarding the performance of this conductive sheet, the volume resistance was 2.0 × 10 ⁶ Ω, the surface resistance was 3.0 × 10 ⁷ Ω, and the charging voltage was 0 V.

This conductive sheet could be used as a work conductive mat by cutting it into a predetermined size.

[0022]

[Effect of device]

 In the present invention, by interposing the conductive sheet layer having a low electric resistance value in the middle of the antistatic sheet layer having a higher electric resistance value than that, it is possible to make the antistatic layer on both front and back surfaces thin, and therefore, The amount of the antistatic agent can be reduced to prevent the bleeding of the antistatic agent from being contaminated, and since the conductive layer is not exposed on the surface, conductive powder such as carbon and short fibers are not worn away. Free of air pollution. Also, since the conduction distance from the front and back antistatic layers to the conductive intermediate layer is shortened, it is excellent in chargeability. Furthermore, since the conductive layers of equal thickness are laminated between the antistatic layers on both the front and back sides, It is a conductive sheet with an excellent structure that has the same electrical performance from the front and back surfaces. Furthermore, it can be arbitrarily colored and has excellent designability. It is used in semiconductor manufacturing plants, precision machine manufacturing plants, and electrical component manufacturing plants. It has excellent performance as a static electricity countermeasure work sheet used in areas where such electronic parts are handled.

[Brief description of drawings]

FIG. 1 is a sectional view of a conductive sheet of the present invention.

[Explanation of symbols]

A, C: Front and back layers made of a colored antistatic thermoplastic synthetic resin sheet B: Intermediate layer made of a conductive thermoplastic synthetic resin sheet

Claims (2)

[Scope of utility model registration request] 1. A conductive carbon black between front and back both surfaces made of a colored antistatic thermoplastic synthetic resin sheet having an antistatic agent and an antistatic plasticizer and a volume resistance of 10 ⁸ to 10 ¹¹ Ω. A conductive thermoplastic synthetic resin sheet having a volume resistance of 10 ² to 10 ⁵ Ω, to which conductive materials such as conductive metal powder, conductive carbon fibers, and conductive metal fibers are added, is laminated as an even intermediate layer. , A conductive sheet having a volume resistance of this laminate of 10 ⁵ to 10 ⁸ Ω. 2. The conductive sheet according to claim 1, wherein the resin forming the colored antistatic thermoplastic resin sheet and the conductive thermoplastic resin sheet is a vinyl chloride resin.