JP2588489Y2 - Conductive sheet - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention can be used in places where electronic components are used, such as semiconductor manufacturing plants, precision machine manufacturing plants, electric component manufacturing plants, and in places where precision equipment using computers is used, such as hospitals and laboratories. The present invention relates to a conductive sheet used for laying under equipment or covering the equipment to protect the equipment from malfunctions and failures due to static electricity.

[0002]

2. Description of the Related Art Conventionally, in a place where electronic components such as a semiconductor manufacturing plant, a precision machine manufacturing plant, and an electric component manufacturing plant are handled, and where a precision machine using a computer is used such as a hospital or a laboratory, static electricity is generated. Conductive materials such as conductive carbon black, conductive carbon fiber, conductive metal powder, and conductive metal fiber are used for thermoplastic resin to protect products from failures and disasters, and to prevent malfunction of precision equipment due to static electricity. A single layer product of a blended conductive thermoplastic resin sheet or an antistatic thermoplastic synthetic resin sheet to which a large amount of an antistatic agent has been added, and a two-layer laminated product thereof have been used.

[0003]

The sheet containing the conductive carbon black has the advantage that the volume resistance can be set relatively low at a low cost, but the working environment at the place of use is limited because the surface is limited to black. It deteriorates, and furthermore, a large amount of conductive carbon black is added, so that it is weak to wear, carbon particles are easily removed from the surface, and it is not preferable because it becomes a pollutant in the work place.

In addition, conductive carbon fiber, conductive metal powder,
The conductive thermoplastic sheet containing the conductive metal fibers can be colored relatively and workability is improved, but the fibers and metal particles are easily removed from the surface and are also undesirable as pollutants.

A sheet to which an antistatic agent is added can be colored, but it is difficult to obtain a performance with a volume resistance of 10 ⁸ Ω or less. The thicker the sheet, the higher the concentration of the antistatic agent per area, and the more easily they migrate to the surface, undesirably contaminating these devices.

Further, even in the case of the above-described two-layer laminated structure of the antistatic sheet layer and the conductive sheet layer, the conductive fibers and particles of the conductive sheet layer are undesirably separated and float to become pollutants.

[0007] Therefore, it is possible to color in addition to black and to have excellent design properties, there is no contamination due to migration of an antistatic agent, and no contamination due to floating of conductive fibers or particles. A flexible sheet was desired.

[0008]

According to the present invention, there is provided a multilayer structure comprising a conductive sheet having a low electric resistance value and an antistatic sheet having a coloring property and a higher electric resistance value than the conductive sheet. A three-layer structure in which a colored antistatic sheet is laminated on the upper and lower sides of a conductive sheet solves the above problems and provides a conductive sheet having excellent electric performance and design. It is.

Means is to provide a conductive carbon between the front and back surfaces of a colored antistatic thermoplastic synthetic resin sheet having a volume resistivity of 10 ⁸ to 10 ¹¹ Ω to which an antistatic agent and an antistatic plasticizer are added. A conductive thermoplastic synthetic resin sheet having a volume resistance of 10 ² to 10 ⁵ Ω to which black, conductive carbon fiber, conductive metal powder, conductive metal fiber, and the like are added is laminated as an intermediate layer, and this laminate is formed. Is a conductive sheet having a volume resistance of 10 ⁵ to 10 ⁸ Ω, and is characterized by a structure capable of obtaining the same electrical performance from both sides.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the cross-sectional structure of the conductive sheet of the present invention, wherein A and C are surface layers made of a colored antistatic thermoplastic resin sheet to which an antistatic agent and an antistatic plasticizer are added. B indicates an intermediate layer made of a conductive thermoplastic resin sheet to which carbon black or the like has been added.

Both front and back layers of a colored antistatic thermoplastic synthetic resin sheet are made of vinyl chloride resin such as vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-urethane copolymer resin, polyethylene, polypropylene, ethylene- Vinyl acetate copolymer resins, olefin resins such as ethylene-acrylate copolymer resins, thermoplastic synthetic resins such as urethane resins, particularly preferably those made of vinyl chloride resins, having a volume resistance to these synthetic resins. Non-ionic, so that a value of 10 ⁸ to 10 ¹¹ Ω can be obtained,
Cationic antistatic agent, dibutoxyethyl phthalate, butyl diglycol adipate, Plasizer M
-Add an antistatic plasticizer such as 300L (Kyowa Hakko) and AM903B (Sekisui Chemical), add a general-purpose plasticizer such as dioctyl phthalate, a stabilizer, a coloring agent, etc., and calender molding, extrusion molding, etc. It is made into a sheet of 0.1 to 1 mm.

The intermediate layer made of a conductive thermoplastic synthetic resin sheet has a volume resistance of 10 to the above thermoplastic synthetic resin.
Single or two types of conductive materials such as powders of carbon, nickel, stainless steel, aluminum, etc. or short fibers or inorganic particles surface-treated with tin oxide, zinc oxide, nickel, etc. to obtain a value of ² to 10 ⁵ Ω 5 to 50
%, And further, a general-purpose plasticizer, a stabilizer and the like are added, and the sheet is similarly formed to a thickness of 0.1 to 1 mm.

An antistatic sheet obtained by adding the above-mentioned antistatic agent and antistatic plasticizer to both surfaces of this conductive sheet is
Heat and press at a temperature of 0 to 200 ° C to laminate and integrate.

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

Examples 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 Calcium carbonate 20 parts by weight

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

Formulation Example 2 Vinyl chloride resin (Nipolit 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 at room temperature for 30 seconds with a Henschel mixer. When the mixture is sufficiently mixed, the mixture is kneaded for 2 minutes with a Banbury mixer heated to 150 ° C. to gel the compound. .

The compound was rolled into a 0.40 mm thick black sheet using 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 colored sheet of Formulation Example 1 is heated and laminated up and down, and a 1.3 mm blue conductive sheet in which the black conductive sheet is laminated in the middle is provided. Was obtained. The performance of this conductive sheet was excellent such that the volume resistance was 2.0 × 10 ⁶ Ω, the surface resistance was 3.0 × 10 ⁷ Ω, and the charged voltage was 0V.

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

[0022]

According to the present invention, the antistatic layer on both the front and back surfaces can be made thinner by interposing a conductive sheet layer having a lower electric resistance value between the antistatic sheet layers having a higher electric resistance value. Therefore, the amount of the antistatic agent per area can be reduced, the contamination of the antistatic agent by bleeding can be prevented, and the conductive layer such as carbon and the short fibers are worn away because the conductive layer is not exposed on the surface. And no airborne pollution. Also, since the conduction distance from the front and back layers of the antistatic to the conductive intermediate layer is shortened, the chargeability is excellent, and furthermore, since the conductive layer having a uniform thickness is laminated between the antistatic layers on both the front and back, It is a conductive sheet of an excellent structure with the same electrical performance from the back side, and it can be arbitrarily colored and has excellent design, such as a semiconductor manufacturing plant, precision machine manufacturing plant, electric component manufacturing plant. It has excellent performance as a work sheet for countermeasures against static electricity used in places where various electronic components are handled.

[Brief description of the drawings]

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

[Explanation of symbols]

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

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-63-261041 (JP, A) JP-A-62-43463 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 E04C 2/00-2/54 D06N 1/00-7/06

Claims (2)

(57) [Scope of request for utility model registration] 1. A conductive film between a front surface and a back surface made of a colored antistatic thermoplastic synthetic resin sheet having a volume resistivity of 10 ⁸ to 10 ¹¹ Ω to which both an antistatic agent and an antistatic plasticizer are added. A conductive thermoplastic synthetic resin sheet having a volume resistivity of 10 ² to 10 ⁵ Ω to which a conductive material such as conductive carbon black, conductive metal powder, conductive carbon fiber, and conductive metal fiber is added is evenly intermediate. A conductive sheet which is laminated as a layer and has a volume resistance of 10 ⁵ to 10 ⁸ Ω. 2. The conductive sheet according to claim 1, wherein the resin constituting the colored antistatic thermoplastic resin sheet and the conductive thermoplastic resin sheet is a vinyl chloride resin.