JPH01180337A - Conductive thermoplastic resin sheet - Google Patents

Abstract

PURPOSE:To keep good conductive capacity and to perfectly suppress the napping of a conductive fiber, by laminating a knitted/woven fabric composed of a heat-meltable fiber and a conductive fiber to a thermoplastic resin film and applying surface treatment to the bonded surface of said film before forming a crosslinked cured film. CONSTITUTION:A knitted/woven fabric composed of a heat-meltable fiber and a conductive fiber is laminated to one surface or both surfaces of a thermoplastic resin film to be integrally fused thereto and corona discharge treatment is subsequently applied to the surface having the knitted/woven fabric laminated thereto of said film and, further, a curable composition based on an unsaturated resin and a reactive diluent is applied to the treated surface and a crosslinked cured film having a thickness of 1-10mum is formed using a curing means such as heat energy, ultraviolet rays, ionizable radiation or the like. As the conductive fiber, one kind of one selected from a carbon fiber, a stainless steel fiber, a carbon composite synthetic fiber, a carbon coated synthetic fiber, an aluminum or aluminum alloy fiber, an aluminum coated synthetic fiber, an aluminum coated glass fiber and an aluminum-coated carbon fiber or a mixture of two or more kinds of them is used.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermoplastic resin sheet having electrical conductivity on its surface.

(Prior Art) Methods for making plastic electrically conductive include a method in which an antistatic agent is applied to a surface of plastic mixed with the plastic, and a method in which carbon black is blended into the plastic as a conductive material. However, in the former case, the surface resistivity is at most 1
Moreover, the surface resistivity changes due to environmental humidity, and the antistatic effect disappears over time. In addition, the latter cannot obtain the desired electrical conductivity unless it is incorporated in such a large amount that the carbon black particles exist continuously within the sheet. However, when a large amount of carbon black is blended, the mechanical strength of the base resin is significantly reduced, resulting in poor processability.

In order to solve the above-mentioned conventional problems, a conductive sheet was developed in which a knitted or woven fabric made of conductive fibers and thermofusible fibers was fused and integrated with a plastic sheet as a base material. It is disclosed in the publication No.-166035.

(Problem to be solved by the invention) However, the surface of the conductive sheet obtained by this method is
There is a problem in that a portion of the conductive fibers on the surface layer peel off from the base material and become fluffy even when lightly rubbed with a cloth or the like. This fluffing phenomenon not only deteriorates the appearance of the conductive sheet, but also causes the conductive fibers to fall off from the sheet when rubbed strongly.
K contaminates the surrounding area and also reduces conductive performance, which is a major obstacle to practical application.

The present inventors have made extensive studies to solve the above problems. As a result, by forming a cross-linked cured film with a thickness of 1 to 10 μm mainly composed of an unsaturated resin and a reactive diluent on the surface layer of the conductive sheet, the fluff of the conductive fibers can be removed without deteriorating the conductive performance. It has been discovered that a conductive sheet can be obtained that can completely prevent this, and based on this knowledge, the present invention has been completed.

(Means for solving problems) The present invention has the following configuration.

1) After laminating a knitted or woven fabric made of thermofusible fibers and conductive fibers on one or both sides of a thermoplastic resin film and fusing them together, the surface of the thermoplastic resin film is bonded to the knitted or woven fabric. A curing composition containing an unsaturated resin and a reactive diluent as main components is applied to the treatment, and heat energy, ultraviolet rays,
A conductive thermoplastic resin sheet on which a crosslinked cured film having a thickness of 1 to 10 μm is formed using a curing means such as ionizing radiation.

2) The conductive thermoplastic resin sheet according to item 1 above, wherein the surface treatment is corona discharge treatment.

3) The conductive thermoplastic resin sheet according to item 1 above, wherein the curing means for the curing composition is an electron beam.

4) The conductive fiber is selected from carbon fiber, stainless steel fiber, carbon composite synthetic fiber, carbon coated synthetic fiber, aluminum and aluminum alloy fiber, aluminum coated synthetic fiber, aluminum coated glass fiber, aluminum coated carbon fiber, or The conductive thermoplastic resin sheet according to item 1 above, which is a mixture of two or more types. - Examples of the thermoplastic resin for the thermoplastic resin film used in the present invention include polyolefin resins such as polyethylene, polypropylene, ethylene/vinyl acetate copolymer, and ethylene/ethyl acrylate copolymer; polystyrene,
Styrenic resins such as acrylonitrile-butadiene-styrene copolymers and acrylonitrile-styrene copolymers; acrylic resins such as polymethyl methacrylate; 6
-Nylon, 6-row nylon, 12-nylon, 6.1
Examples include polyamide resins such as 2-nylon, polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyvinyl chloride, polycarbonate, poly7-ethylene oxide, and mixtures thereof.

These resins include heat stabilizers, weather stabilizers, plasticizers, lubricants, slip agents, antistatic agents, charge transfer polymers, nucleating agents, flame retardants, tackifiers (petroleum resins, etc.), pigments, dyes, Inorganic fillers, organic fillers, etc. can be blended depending on the purpose.

In addition, thermofusible fibers used in conductive knitted and woven fabrics include acrylic fibers, polyamide fibers, polyester fibers, polyolefin fibers, polyvinyl chloride fibers, etc., or mixtures thereof, and thermoplastic base materials. There is no particular restriction as long as it can be heat-sealed to the resin. These fibers may be blended with flame retardants, colorants, antistatic agents, charge transfer polymers, etc., if necessary.

The heat-fusible fibers preferably have a fiber diameter of about 0.5 to 10 denier.

Next, as conductive fibers, metal or metal compound composite synthetic fibers, metal or metal compound coated synthetic fibers, metal or metal compound coated glass fibers, metal or metal compound coated carbon fibers, carbon composite Tanari fibers, carbon coated synthetic fibers, Carbon fibers, metal fibers, etc. and mixtures thereof may be mentioned. In addition, in the case of the present invention, in order to strengthen the adhesion between the crosslinked cured film and the surface of the conductive thermoplastic resin sheet, it is necessary to perform surface treatment on the surface of the conductive thermoplastic resin sheet to increase the wetting tension on the surface. . - Corona discharge treatment is used as a surface treatment method within the film. However, when corona discharge treatment is performed in the atmosphere, care must be taken because some conductive fibers lose their conductivity due to oxidation reactions caused by corona discharge. By the way, corona discharge treatment in an inert gas atmosphere is possible, but the safety of the work is
There are many problems with the equipment and it is not very practical.

Carbon fibers, stainless steel fibers, carbon composite synthetic fibers, carbon-coated synthetic fibers, aluminum and aluminum alloy fibers, aluminum-coated synthetic fibers, aluminum-coated glass have no deterioration in conductive performance when subjected to corona discharge treatment in the atmosphere. It is desirable to use one type or a mixture of two or more selected from fibers and aluminum-coated carbon fibers.

The conductive fibers preferably have a fiber diameter of about 1 to 30 μm.

In addition, even if the knitted/woven fabric of the present invention is mixed with high melting point fibers or non-melting fibers in addition to the above-mentioned heat-melting fibers and conductive fibers, the spun yarn may be mixed with the warp or weft. A method of weaving a woven fabric using at least a part of the filament yarn, a method of weaving a woven fabric using a filament yarn of thermofusible fiber and a filament yarn of conductive fiber, and a method of weaving a woven fabric using filament yarn of thermofusible fiber and conductive fiber. It can be obtained by various known methods such as weaving using twisted yarns to obtain woven fabrics, and knitting spun yarns, filament yarns, and intertwisted yarns as described above to obtain silk cloth and lace. , those having a basis weight M of 200 f/Wt or less are preferably used.

The ratio of conductive fibers used in conductive knitted and woven fabrics is 1 to 9.
9x% by weight, preferably 3-70x% by weight.

The unsaturated resins that are the main components of the curing composition used in the present invention include epoxy resins, polyester resins, polyurethane resins, polyamide resins, and melamine resins, but especially polyesters with high radiation activity , epoxy, polyurethane, polyether, and polyols with an acryloyl group introduced into the end or side chain of the molecule, such as polyester acrylate, polyepoxy acrylate, polyurethane acrylate, polyether acrylate, polyol acrylate, etc. are preferably used. It will be done. These are usually molecules -j & 250~
It is used in the form of about 1,500 oligomers, and the number of acryloyl groups per molecule is 2 to 5.

Examples of reactive diluents include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate), and 1,6-hexane diol diluent. acrylate, neopentyl glycol diacrylate, polyfunctional hexamer such as triacryloxyethyl phosphate, vinylpyrrolidone, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,
Tetrahydromylene acrylate, butoxyethyl acrylate, ethyl diethylene glycol acrylate,
2-Ethylhexyl acrylate, 10-hexyl acrylate, phenoxyethyl acrylate, 2-hydro-
One type or a mixture of 28 or more monofunctional monomers such as 3-phenyloxypropyl acrylate and dicyclopentadiene acrylate are used.

Various additives are further added to the curable composition as necessary. These additives include wood, various natural or synthetic polymeric substances, fillers, pigments, dyes, matting agents, plasticizers, viscosity modifiers, solvents, and various other auxiliaries.

Examples of the above-mentioned polymeric substances include (meth)acrylic,
Urethane-based, butadiene-based, ethylene-based, vinyl chloride-based, vinylidene chloride-based, polyether-based, alkyd-based,
Polymers containing saturated or unsaturated groups belonging to polyester, polyamide, vinyl acetate, vinyl formal, vinyl butyral, vinyl pyrrolidone, vinyl alcohol, etc., copolymers, prepolymers, oligomers, cellulose, and their like. derivatives, rosin and its derivatives, phenolic resin and its derivatives, petroleum resins, ketone resins, silicone resins, natural and synthetic oils and fats,
Examples include waxes and the like.

Examples of fillers include fibers and powders of glass, metals and metal compounds, silica, pallite, calcium carbonate, and the like.

Pigments include extender pigments such as alumina white, clay, talc, barium carbonate, barium sulfate, zinc white, lead white, yellow lead,
Inorganic pigments such as ultramarine, navy blue, titanium oxide, zinc chromate, red iron, carbon black, etc., Brilliant Carmiso 6
Examples of organic pigments include B, Permanent Red R1 Benzidine Yellow, Lake Red C, and Phthalocyanine Blue.

Examples of dyes include basic dyes such as magenta and rhodamine, direct dyes such as direct left scarlet and direct orange, and acidic dyes such as roserin and methanil yellow.

Examples of the matting agent include organic matting agents such as polyacrylonitrile powder, and inorganic matting agents such as powdered silica or modified products thereof.

Examples of plasticizers include dibutyl phthalate, dioctyl phthalate, chlorinated paraffin, and tricresyl phosphate.

Examples of the viscosity modifier include bentonite, silica gel, aluminum octoate, and the like.

Examples of the solvent include various solvents belonging to the ketone type, alcohol type, varnish type, ether type, aliphatic, alicyclic, aromatic, hydrocarbon type, and the like.

Other auxiliary agents include known antifoaming agents, leveling agents,
Examples include surfactants, ultraviolet absorbers, twist retardants, charge transfer plate polymers, and the like.

If the curing method mainly uses thermal energy such as a heating furnace, infrared ray irradiation, microwave irradiation, etc., for example, ketone peroxide, hydroperoxide, dialkyl peroxide, cyacyl peroxide, etc. Such radical initiators are used. In the case of curing at a relatively low temperature such as room temperature curing, for example, a combination of ketone peroxide or diacyl peroxide and a metal salt, a combination of ketone peroxide, diacyl peroxide, hydroperoxide and a reducing amine, etc. It is desirable to use an accelerator in combination.

In addition, when the curing means is ultraviolet rays, for example, benzoin compounds such as pentuin, benzoin methyl ether, pentuin ethyl ether, benzoin propyl ether, benzoin butyl ether, pentuin octyl ether, benzyl, diacetyl, methylantho2Φone, acetophenone, etc. , carbonyl compounds such as benzophenone, sulfur compounds such as diphenyl disulfide and dithiocarbamate, naphthalene compounds such as a-chloromethylnaphthalene, and photoinitiators such as metal salts such as anthracene and iron chloride. can.

First, a thermoplastic resin serving as a base material and a conductive knitted/woven fabric are bonded and fused together using a known method such as an extrusion lamination method, a hot roll compression method, or a hot press method. At this time, it is necessary to select temperature conditions such that the thermofusible fibers contained in the conductive knitted/woven fabric are completely melted and integrated with the thermoplastic resin that is the base material.

For example, in the case of the extrusion lamination method, first, a thermoplastic resin serving as a base material is melt-kneaded in an extruder to a resin temperature of about 180 to 280°C, and extruded into a film through a T-die. Next, a conductive knitted or woven fabric is superimposed on one or both sides of the resin film, and the base material and the conductive knitted or woven fabric are fused together by pressing with a pair of rolls heated to about 30 to 160°C. do it. At this time, in order to facilitate the integration of the conductive knit/woven fabric and the base material, a heat-resistant plastic film (thickness: (preferably about 10 to 50 .mu.m)), and after pressurizing and fusion bonding in this superimposed state, cooling and solidifying, the heat-resistant plastic film may be peeled off and removed.

In addition, in the case of the hot roll compression method, any thermoplastic resin may be used.

The thickness of the conductive thermoplastic resin sheet is 0.03 to 6.01
It can be arbitrarily selected within the range of m.

Next, in order to improve the adhesion with the curing composition, a surface treatment is applied to the surface of the highly conductive thermoplastic resin sheet obtained by the above method 1 to which the conductive knitted/woven fabric is bonded. Surface treatments include various known methods such as chemical treatment, coupling treatment, primer treatment (polymer coating), surface grafting, ultraviolet irradiation treatment, plasma treatment (corona discharge treatment, glow discharge treatment, plasma jet treatment), plasma polymerization treatment, etc. can be used. Among these treatment methods, it is most preferable to use corona discharge treatment, which allows continuous production and is highly versatile. In the case of the present invention, it is desirable to use a corona discharge treatment device for treating conductors (corona discharge treatment devices for insulators are not preferable because sparks fly due to discharge and charring occurs).
. Further, it is desirable that the corona discharge treatment be performed immediately after manufacturing the conductive thermoplastic resin sheet.

Surface wetting tension of surface treated surface (A STM -D -
2578) is 35 dyne/3 or more,
It is preferable to adjust to 38 dyne/ls or more.

A crosslinked cured film with a thickness of 1 to 10 μm is formed on the surface.

Coating devices for the curing composition include play coaters, knife coaters, roll coaters (3 roll coaters,
In addition to direct coater, reverse roll coater), there are various print type coaters such as screen, offset, gravure, letterpress, and flexo.

A spray type coater may be used depending on the case.

The curing composition may be applied to the entire surface of the conductive thermoplastic resin sheet (petal printing #), or it may be applied partially using a halftone plate (halftone plate) of various shapes. You can.

The amount of the curing composition applied to the surface of the conductive thermoplastic resin sheet may be adjusted so that the thickness of the crosslinked cured film formed on the sheet surface is in the range of 1 to 10 μm, preferably 2 to 7 μm. preferable. The thickness of the cured film is 1 ttW
If it is less than 1, the occurrence of fluffing of the conductive fibers cannot be completely suppressed, and if it exceeds the reverse KIOμjfft-, the surface resistivity becomes 1012 Ω/mouth or more, which deteriorates the conductive performance, which is not preferable.

Curing methods for the curing composition include room temperature curing, heating furnace, infrared irradiation, microwave irradiation, etc., which mainly utilize thermal energy, ultraviolet irradiation, and ionizing radiation such as electron beams and R-rays. Although irradiation may be used, electron beam irradiation is preferred because of its productivity (curing time) and less deterioration of the thermoplastic resin film as a base material due to heating.

Electron beam irradiation is performed using an electron beam accelerator using the scanning Jung beam method or the curtain beam method. It is carried out under a gas atmosphere (0, concentration 400 ppm or less).

The curing conditions for the coating film are an electron beam voltage of 125 to 300 KV and a dose of about 1 to 20 Mrad.

(Examples) Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The measurement methods used in the Examples and Comparative Examples are as follows.

(1) Melt flow rate ASTM D-1238 (temperature 230°C, load 2.16
t9) K compliant.

(2) High melt flow rate ASTM D-1238 (temperature 230°C, load 10.2
#) Compliant.

(3) Measured based on Isitaktic Pentad Fraction Macromolecules 8.687 (1975).

13C-NMRt- is used and is the isotactic fraction in pentad units in the polypropylene molecular chain.

(4) Surface resistivity (Ω/port) A, Computing Digital Multimeter R6877 manufactured by Takeda Riken B, High resistance meter stack TR-3 manufactured by Tokyo Denshi ■ The electrode is a circular electrode (positive electrode: outer diameter 701 @ φ circle Plate, negative electrode: outer diameter 110
flφ, inner diameter 80j11φ ring shape) is used.

Measure using In only if the measured value is 107Ω or more. Surface resistivity - 15π x Actual measurement value (Ω) Example 1 Cut stainless steel fiber (fiber diameter 12 μm) 155
A conductive woven fabric (60 lengths/in s weft) is produced by weaving a spun yarn (30 denier) made from a fiber mixture consisting of 85% by weight of cut polypropylene fibers (fiber diameter 2 denier). 52 pieces/in).

Next, isotactic pentad fraction (b) 10,
968, melt flow sea) (MFR)■0.53
f/10 win% high melt flow rate (
HMFR)=28.5f/10m1n highly crystalline propylene homopolymer with 1.3.5-) listyl-2,4,6
-) 0.10% by weight of lith(3,5-di-t-butyl-4-hydroxybenzyl)benzene and tetrakis(methylene(3,5-di-t-butyl-4-hydroxybenzyl))methane Polypropylene sheet blended with 0.103% by weight and calcium stearate o, o s .

Both 11 fK conductive woven fabrics of the resin film are overlapped, and 8
A 200ff diameter touch roll (
The base material and the conductive woven fabric were crimped using a chill roll (metal roll) with a diameter of 50011# and a thickness of 1.011mm.
A conductive polypropylene sheet of No. 1 was obtained. The polypropylene fibers of the conductive woven fabric were then passed between heated rolls heated to 160°C, completely melting, and integrated with the base polypropylene sheet, leaving only the stainless steel fibers on the surface. A conductive polypropylene sheet adhered in the form of a mesh was obtained.

The surface resistivity of the conductive polypropylene sheet at this time was 10' to 10'' Ω/hole on both sides.

Next, both surfaces of the conductive polypropylene sheet were subjected to corona discharge treatment in the atmosphere using a corona discharge treatment apparatus for conductors. Wetting tension on both surfaces is 41 dyne/
(W). Also, the true resistivity of the conductive polypropylene sheet after corona discharge treatment was 104 to 10' on both sides.
Ω/mouth was completely unchanged from before the corona discharge treatment.

Further, as a curing composition, a mixed composition consisting of 42% by weight of polyepoxy polyrylate oligomer, 55% by weight of 2-hydroxypropyl acrylate, 2% by weight of betaine surfactant, and 1% by weight of polymerization inhibitor was prepared. .

The composition was applied to the entire surface (one side) of the conductive polypropylene sheet using a gravure roll, and then placed in an electron curtain conveyor shop electron beam irradiation device (Electron EPZ-2 Dai (trademark) manufactured by ESI) under an N2 atmosphere. (
OS concentration 200 ppm), acceleration voltage 140 KV, dose 6
A cross-linked cured film with a thickness of 3 μm was formed by irradiation with an electron beam using Mrad'. Similarly, a crosslinked cured film with a thickness of 3 μm was formed on the other side as well. No fluffing of the conductive fibers was observed on either surface, and even when the surface was strongly rubbed with cloth, fingernails, etc., no fluffing of the conductive fibers occurred at all.

Moreover, 1. The surface resistivity of the conductive polypropylene sheet after the formation of the crosslinked cured film was 104 to 10'Ω/hole on both sides, and had good conductivity.

Example 2 20% by weight of cut carbon-coated polyester fiber (fiber diameter 3 denier) and cut polyvinyl chloride fiber (Teviron (trademark): manufactured by Teijin ■, fiber diameter 3 denier) 8
Spun yarn made from a fiber mixture consisting of 0% by weight (15
A conductive woven fabric (number of vertical stitches: 115, number of weft stitches: 114) was obtained by weaving a conductive woven fabric.

Next, 8.0 parts by weight of dioctyl phthalate, 2.5 parts by weight of Schiftyltin alkyl maleate, 0.5 parts by weight of butyl stearate, and 0.4 parts by weight of stearyl alcohol were added to 100 parts by weight of polyvinyl chloride having an average degree of polymerization of 1300. A polyvinyl chloride compound having a blending ratio of 1 part by weight and 0.1 part by weight of stearic acid was melt-kneaded in an extruder with a diameter of 65 fi, and extruded into a film at a resin temperature of 185° C. through a T-die with a width of 500 nm.

The conductive fabric was layered on both sides of the cough resin film, and heated to 70°C.
Touch low # (gold 11) with a diameter of 200fi through hot water of
a-le) and il [diameter 400ta? The base material and the conductive woven fabric were crimped with a roll roll (metal roll) to obtain a conductive polyvinyl chloride sheet having a thickness of 0.7 fi. Next, when the sheet was heated to fI: 170°C and passed between heated rolls, the polyvinyl chloride fibers in the conductive woven fabric were completely melted.
It was integrated with the base polyvinyl chloride sheet, and only the carbon-coated polyester fibers were adhered to the surface in a mesh pattern.

At this time, the surface resistivity of the conductive polyvinyl chloride sheet was 10'Ω/hole on both sides.

Next, both sides of the conductive polyvinyl chloride sheet were subjected to corona discharge treatment in the atmosphere using a corona discharge treatment apparatus for conductors. Wetting tension on both sides is 43 dyne/
It was ag. Furthermore, the surface resistivity of the conductive polyvinyl chloride sheet after corona discharge treatment was 106 Ω/mouth on both sides, which was completely unchanged from that before corona discharge treatment. .

In addition, the curing composition includes 48% by weight of polyurethane acrylate oligomer, 45% by weight of neopentyl glycol diacrylate1, and 6% by weight of extender pigment (alumina white).
and 1% by weight of a polymerization inhibitor was prepared.

The composition was rolled into a dotted gravure roll (dot area: 60%).
It was coated on the surface (one side) of the conductive polyvinyl chloride sheet, and irradiated under N atmosphere (0, concentration 200 ppm) at an acceleration voltage of 160 KV and a dose of 12 Mrad to form a crosslinked cured film with a thickness of 7 μm. Similarly,
A crosslinked cured film with a thickness of 7 μm was also formed on the other side.

No fluff of the conductive fibers was observed on either surface, and even when the surface was strongly rubbed with cloth, fingernails, etc., no fluff of the conductive fibers occurred at all.

Further, the surface resistivity of the conductive polyvinyl chloride sheet after the formation of the crosslinked cured film was 10 6 Ω/hole on both sides, indicating good conductivity.

Example 3 90% by weight of cut acrylonitrile/vinyl chloride composite fiber (Kanebuchi Chemical Co., Ltd. Risekanekalon SB (trademark), fiber diameter 1.5 denier) and cut austenitic stainless steel fiber (Nippon Seisen Co., Ltd.) ■Made by Naslon (trademark)
A conductive knitted fabric having a basis weight of 80 fl/111 was obtained by knitting a spun yarn (15 denier) made from a fiber mixture of 10 wt.

Next, %GP-PS resin (Nippon Steel Chemical ■Sho Estyrene G
-32 (Trademark)) T-Melt knead with an extruder with a diameter of 40IIlIIIl, and put it into a T-die of cod with a width of 300mm at a resin temperature of 230°C.
It was extruded into a film. The conductive knitted fabric is superimposed on one side of the resin film, and the base material and the conductive knitted fabric are crimped with a pair of polygingerol C (all 1140 ml) passed through hot water at 60°C,
A conductive polystyrene sheet having a thickness of 0.6 fi was obtained.

Next, when the Mukuro sheet was passed between hot rolls heated to 180°C, the acrylonitrile/vinyl chloride copolymer fibers in the conductive knitted fabric were completely melted, integrated with the base polystyrene sheet, and the surface Only the stainless steel fibers were stuck in a mesh pattern. The surface resistance of the conductive knitted fabric back surface of the sheet was 105Ω/mouth.

Next, the conductive knitted fabric laminated surface of the conductive polystyrene sheet was subjected to corona discharge treatment in the atmosphere using a corona discharge treatment apparatus for conductors. Wetting tension of treated surface is 39 dy
ne/C1l. Furthermore, the surface resistivity of the conductive knitted fabric laminated surface of the conductive polystyrene sheet after the corona discharge treatment was no different from that before the corona discharge treatment.

In addition, as a curing composition, a mixed composition consisting of 48% by weight of polyurethane acrylate oligomer, 45% by weight of neopentyl glycol diacrylate, 6% by weight of extender pigment (alumina white), and 11% by weight of polymerization inhibitor was prepared.

The composition was applied to the entire surface of the conductive knitted fabric laminated surface of the conductive polystyrene sheet using a gravure roll, and then applied using an electron beam irradiation device Electron KPZ-2 (trademark) manufactured by CESI Corporation. Acceleration voltage 140 KV under N atmosphere (0!concentration 150 ppm)
, and was irradiated with an electron beam at a dose of 6 Mrad to form a crosslinked cured film with a thickness of 5 μm.

No fluffing of the conductive fibers was observed on the laminated surface of the conductive knitted fabric on which the crosslinked cured coating was formed, and even when the surface was strongly rubbed with cloth, fingernails, etc., no fluffing of the conductive fibers occurred at all. Also, the surface resistivity is 106~10'Ω
/ mouth and had good conductivity.

Example 4 From 92% by weight of cut acrylonitrile/vinyl chloride copolymer fiber (Kanebuchi Kagaku Kogyo Kashi Kanekalon (trademark), 3 denier fiber diameter) and 8% by weight of alum-deposited polyester fiber (3 denier fiber diameter) A conductive knitted fabric with a basis weight of 120 f/g was obtained by knitting a spun yarn (20 denier) made from a fiber mixture of the following.

Next, the ABS resin was melt-kneaded using an extruder with a diameter of 40+W, and extruded into a film through a T-die with a width of 300111 at a resin temperature of 250°C. The conductive knitted fabric was superimposed on both sides of the resin film, and the base material and the conductive knitted fabric were crimped with a pair of polygingerols (metallic wax, FL;) that had been passed through hot water at 80°C to form a film with a thickness of 1.2111 mm. A conductive ABS resin sheet was obtained.

Next, when the sheet was passed through a hot tub heated to 180°C, the acrylonitrile/vinyl chloride copolymer fibers in the conductive knitted fabric were completely melted and integrated with the base ABS resin sheet. The aluminum-deposited polyester fibers were adhered to the surface in a mesh pattern. The surface resistivity of the electrically conductive knitted fabric of the sheet was 106Ω/hole.

Next, both pages of the conductive ABS resin sheet were subjected to corona discharge treatment in the atmosphere using corona discharge treatment at for conductors. The wetting tension of the treated surfaces is 40 dyn/c.
It was IM. In addition, conductive ABS after corona discharge treatment
The surface resistivity of the resin sheet was 101 Ω/hole on both sides, which was well unchanged from before the cycorona discharge treatment.

Further, a mixed composition consisting of 54% by weight of polyepoxy acrylate oligomer, 45% by weight of 2-hydroxyethyl acrylate, and 1% by weight of a polymerization inhibitor was prepared as a curing composition.

The composition was coated on the entire surface of the conductive knitted fabric of the conductive ABS resin sheet using a gravure roll, and subjected to an electric four curtain compare type electron beam irradiation device (ESI).
N using Electron EPZ-211 (trademark) manufactured by
! Acceleration voltage 1 in atmosphere (02 concentration 200 ppm)
Irradiated with electron beam at 40KV and dose of 6 Mrad to a thickness of 3μm
Forms a cross-linked cured film. Similarly, a crosslinked cured film with a thickness of 3 μm was formed on the other side as well.

The conductive AB8 resin sheet with a cross-linked cured film shows no fluffing of the conductive fibers on both sides, and even if the surface is strongly rubbed with cloth, fingernails, etc., no fluffing of the conductive fibers occurs at all. I didn't. First, the surface resistivity is 1
It had good electrical conductivity of 0' to 10' Ω/hole.

Example 5 Polyester polyacrylate 64 as curing composition
A mixed composition consisting of 30% by weight of polyol polyacrylate, 51% by weight of trimethylolpropane triacrylate, and 1% by weight of benzoyl peroxide was prepared.

The composition was coated with a bar coater on one side of a conductive polypropylene sheet (corona discharge treated) similar to that used in Example 1, and heat treated in an open environment at 130°C for 5 minutes to form a 7 μm thick sheet. A crosslinked cured film was formed. Similarly, a cross-linked cured film with a thickness of 7 μm was formed on the other side as well.

No fluff of the conductive fibers can be seen in either case.
Furthermore, even if the surface was strongly rubbed with cloth, fingernails, etc., no fluffing of the conductive fibers occurred.

Moreover, the surface resistivity of the conductive polypropylene sheet after the formation of the crosslinked cured film was 10' to 105 Ω/hole on both sides, indicating good conductivity.

Example 6 Polyester polyacrylic L'-)4 as a curing composition
A mixed composition consisting of 3% by weight of polyol polyacrylate, 40% by weight of polyol polyacrylate, 15% by weight of trimethylolpropane triacrylate, and 2% by weight of benzyl was prepared.

The composition was applied with a percoater to one side of a conductive polycyclized vinyl sheet (corona discharge treated) similar to that used in Example 2, and irradiated with ultraviolet rays to form a crosslinked cured film with a thickness of 5 μm. Ta. Similarly, a crosslinked cured film with a thickness of 5 μm was formed on the other side as well.

No fluffing of the conductive fibers was observed in either case.
Moreover, even if the surface tube was strongly rubbed with cloth, fingernails, etc., no fluffing of the conductive fibers occurred.

Ninth, the surface resistivity of the conductive polyvinyl chloride sheet after the formation of the cross-linked cured film was 106 Ω/hole on both sides, indicating good conductivity.

Comparative Example 1 A conductive polypropylene sheet was obtained in accordance with Example IK, except that the thickness of the crosslinked cured film was 15 μm in Example 1. No fuzzing of the conductive fibers was observed on either side of the sheet, and no fuzzing of the conductive fibers occurred even when the surface was strongly rubbed with cloth, fingernails, etc.

However, the surface resistivity of the conductive polypropylene sheet after the formation of the crosslinked cured film was significantly deteriorated to 10<12 >Ω/mouth or more on both sides, and it could hardly be called a conductive sheet.

Comparative Example 2 When the surface resistivity was measured using the conductive polypropylene sheet in which the crosslinked cured coating "I&:t" was not formed in Example 1, the surface resistivity was 104 to 104 on both sides.
It was good at 10'Ω/mouth, but when the surface was strongly rubbed with a fingernail or cloth, the conductive fibers became fluffy.

Comparative Example 3 A conductive polyvinyl chloride sheet was obtained in accordance with Example 2, except that the thickness of the crosslinked cured film was 15 μm. No fuzzing of the conductive fibers was observed on either side of the sheet, and no fuzzing of the conductive fibers occurred even when the surface was strongly rubbed with cloth, fingernails, etc.

However, the surface resistivity of the conductive polyvinyl chloride sheet after the formation of the crosslinked cured film was significantly deteriorated to 1012 Ω/mouth or more on both sides, and could hardly be called a conductive sheet.

Comparative Example 4 When the surface resistivity was measured using the conductive polyvinyl chloride sheet in which no crosslinked cured film was formed in Example 2, the surface resistivity was good at 106Ω/hole on both sides, but the surface When rubbed strongly with a fingernail or cloth, the conductive fibers were observed to become fluffy.

(Effects of the Invention) The conductive thermoplastic resin sheet of the present invention maintains good conductivity by forming a cross-linked cured film of 1 to 10 μm on the surface layer of the sheet, which is firmly adhered to the base sheet. It is now possible to completely suppress the fuzzing of conductive fibers, and the conventional problems of deterioration in appearance due to the fuzziness of conductive fibers, contamination of the surrounding area due to shedding of conductive fibers, and deterioration of conductivity are not seen at all. It is a sex sheet.

Therefore, the conductive thermoplastic resin sheet of the present invention independently
Or, by compounding with other materials, IC%L
It can be suitably used for packaging of semiconductors such as SI, electronic parts, precision mechanical parts, etc., and as a material for clean rooms.

that's all Patent developer Chisso Co., Ltd.

Claims (1)

[Claims] 1) A knitted or woven fabric made of thermofusible fibers and conductive fibers is bonded to one or both sides of a thermoplastic resin film and fused together, and then the knitted or woven fabric is bonded together. A curing composition containing an unsaturated resin and a reactive diluent as main components is applied to the surface-treated surface, and the composition is cured to form a cross-linked film with a thickness of 1 to 10 μm. A conductive thermoplastic resin sheet with a coating formed on it. 2) The conductive thermoplastic resin sheet according to claim 1, wherein the surface treatment is corona discharge treatment. 3) The conductive thermoplastic resin sheet according to claim 1, wherein the curing means for the curing composition is an electron beam. 4) The conductive fiber is one type selected from carbon fiber, stainless steel fiber, carbon composite synthetic fiber, carbon coated synthetic fiber, aluminum and aluminum alloy fiber, aluminum coated synthetic fiber, aluminum coated glass fiber, aluminum coated carbon fiber, or The conductive thermoplastic resin sheet according to claim 1, which is a mixture of two or more types.