JPH1180682A - Crosslinking type electroconductive pressure sensitive adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition excellent in long-term durability, humidity resistance in particular, easily reapplicable and excellent also in adhesion workability by forming on the surface of metal foil a post cure type pressure sensitive adhesive layer with electroconductive particles dispersed therein, the layer containing a polymer consisting mainly of an ethylene-vinyl acetate type copolymer and a crosslinking agent. SOLUTION: An ethylene-vinyl acetate type copolymer comprises one or more selected from the group consisting of (A) an ethylene-vinyl acetate copolymer with a vinyl acetate content of 20-80 wt.%, (B) a copolymer of ethylene with vinyl acetate and an acrylic and/or methacrylic monomer with a vinyl acetate content of 20-80 wt.% and an acrylic and/or methacrylic monomer content of 0.01-10 wt.% and (C) a copolymer of ethylene with vinyl acetate and a maleic acid and/or maleic anhydride with a vinyl acetate content of 20-80 wt.% and a maleic acid and/or maleic anhydride content of 0.01-10 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross-linked conductive pressure-sensitive adhesive tape, and more particularly to a cross-linked conductive pressure-sensitive adhesive tape which is useful for forming an electromagnetic wave shielding light transmitting window material for a PDP (plasma display panel) and a conductive portion of various electric devices. The present invention relates to a conductive adhesive tape.

[0002]

2. Description of the Related Art A conductive tape provided with an adhesive layer in which conductive particles are dispersed on one surface of a metal foil is used for assembling an electromagnetic wave shielding light transmitting window material for PDP and various electric devices.
It is used for forming conductive parts or electrode take-out parts.

The adhesive layer of a conventional conductive tape is generally formed by dispersing conductive particles in an adhesive mainly composed of an acrylic adhesive, an epoxy or phenolic resin and a curing agent. From the viewpoint of convenience and the like, a one-component thermosetting adhesive has become mainstream as an adhesive.

[0004]

However, the conventional acrylic pressure-sensitive adhesive has the following disadvantages. A conductive tape using an acrylic pressure-sensitive adhesive as an adhesive has a high initial adhesive strength, but has low heat resistance and has a problem in long-term durability.

The conductive tape using an epoxy or phenolic resin as an adhesive has the following disadvantages. There is almost no stickiness, and it is difficult to temporarily fix the adhered object. Some have increased adhesion, but not enough. Also, it is difficult to re-paste. For this reason, retouching work is almost impossible. In particular, phenolic resins have poor moisture and heat resistance,
Poor long-term durability. In particular, the heating temperature for curing epoxy resin is 1
It is as high as 50 ° C. or higher, and adhesion is not easy.

[0006] The present invention solves the above-mentioned conventional problems, and has a long-term durability, particularly excellent moisture resistance, a moderate adhesive strength, easy re-attachment and excellent bonding workability. It is intended to provide an adhesive tape.

[0007]

The cross-linked conductive pressure-sensitive adhesive tape of the present invention is a cross-linked conductive pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer in which conductive particles are dispersed on at least one surface of a metal foil. The pressure-sensitive adhesive layer is a post-crosslinkable adhesive layer containing a polymer mainly composed of an ethylene-vinyl acetate copolymer and a crosslinking agent thereof.

Since the pressure-sensitive adhesive layer of the cross-linked conductive pressure-sensitive adhesive tape of the present invention is a post-cross-linking adhesive layer containing an ethylene-vinyl acetate copolymer and a cross-linking agent thereof, it has the following features.

(I) It has excellent adhesiveness, and can be temporarily fixed to an object to be adhered easily and with an appropriate adhesive force. (ii) The adhesive strength before cross-linking is sufficient for temporary fixing, but is not so strong, so that it can be re-applied and repair work can be easily performed. (iii) Since the adhesive strength after crosslinking and curing is extremely strong, high adhesive strength can be obtained. (iv) High moisture resistance and heat resistance, and excellent long-term durability. (v) Even in the case of thermal crosslinking, crosslinking can be generally performed at a temperature of 130 ° C. or lower, and photocrosslinking can be performed. Since crosslinking and curing can be performed at a relatively low temperature, the bonding operation is easy.

In the present invention, the ethylene-vinyl acetate copolymer includes (A) an ethylene-vinyl acetate copolymer having a vinyl acetate content of 20 to 80% by weight, and (B) a vinyl acetate content of 20 to 80% by weight. 80% by weight, and the content of acrylate and / or methacrylate monomers is 0.0%.
1 to 10% by weight of a copolymer of ethylene, vinyl acetate and acrylate and / or methacrylate monomers, and (C) a vinyl acetate content of 20 to 80% by weight, maleic acid and / or maleic anhydride The acid content is preferably one or more selected from the group consisting of a copolymer of ethylene, vinyl acetate, maleic acid and / or maleic anhydride having a content of 0.01 to 10% by weight.

The crosslinking agent is an organic peroxide or a photosensitizer, and the content of the crosslinking agent in the polymer in the pressure-sensitive adhesive layer is preferably 0.1 to 10% by weight.

[0012]

Embodiments of the present invention will be described below in detail.

The conductive particles used in the present invention only need to be electrically good conductors, and various types can be used. For example, copper, silver, metal powder such as nickel,
A resin or a ceramic powder coated with such a metal can be used. Also, there is no particular limitation on its shape, flaky, dendritic, spherical, pellet,
Any shape such as a star shape, a corn sugar (granular shape having a large number of protrusions) and the like can be taken.

The compounding amount of the conductive particles is preferably 0.1 to 15% by volume based on a polymer described later constituting the pressure-sensitive adhesive, and the average particle size thereof is 0.1 to 100 μm.
m is preferable. In this way, by defining the amount and the particle size, the condensation of the conductive particles is prevented,
Good conductivity can be obtained.

The polymer constituting the pressure-sensitive adhesive layer of the present invention comprises:
An ethylene-vinyl acetate copolymer selected from the following (A) to (C) as a main component, and a melt index (MF)
R) is from 1 to 3000, especially from 1 to 1000, especially from 1 to
A value of 800 is preferred.

As described above, when the MFR is from 1 to 3000 and the vinyl acetate content is from 2 to 80% by weight,
By using the copolymer (C), the tackiness before cross-linking increases, the workability is improved, and the cured product after cross-linking has a high three-dimensional cross-linking density, and exhibits strong adhesion.
Also improves moisture resistance and heat resistance.

(A) Ethylene-vinyl acetate copolymer having a vinyl acetate content of 20 to 80% by weight (B) Vinyl acetate content of 20 to 80% by weight, and an acrylate and / or methacrylate monomer Copolymer of ethylene and vinyl acetate with acrylate and / or methacrylate monomers having a content of 0.01 to 10% by weight (C) The vinyl acetate content is 20 to 80% by weight, and maleic acid and / or Or the content of maleic anhydride is 0.01
Copolymer of ethylene, vinyl acetate, maleic acid and / or maleic anhydride in an amount of 10 to 10% by weight In the above ethylene-vinyl acetate copolymers (A) to (C), ethylene-vinyl acetate copolymer Has a vinyl acetate content of 20 to 80% by weight, preferably 20 to 6% by weight.
0% by weight. If the vinyl acetate content is less than 20% by weight, a sufficient degree of crosslinking cannot be obtained when crosslinking and curing at high temperatures, while if it exceeds 80% by weight, the ethylene-vinyl acetate copolymers (A) and (B) In the polymer, the softening temperature of the resin becomes low, and storage becomes difficult, which is a practical problem.
In the case of the ethylene-vinyl acetate copolymer (C), the adhesive layer strength and durability tend to be significantly reduced.

In the copolymer (B) of ethylene, vinyl acetate and acrylate and / or methacrylate monomers, the content of the acrylate and / or methacrylate monomers is 0.01 to 10% by weight. , Preferably 0.05 to 5% by weight. When the content of the monomer is less than 0.01% by weight, the effect of improving the adhesive strength is reduced, while when it exceeds 10% by weight, the processability may be reduced. In addition, as an acrylate type | system | group and / or a methacrylate type | system | group monomer, the monomer selected from an acrylate or a methacrylate type monomer is mentioned, Acrylic acid or methacrylic acid is a C1-C20, especially -18 unsubstituted. Alternatively, an ester with a substituted aliphatic alcohol having a substituent such as an epoxy group is preferable, and examples thereof include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, and glycidyl methacrylate.

In the copolymer (C) of ethylene, vinyl acetate, maleic acid and / or maleic anhydride, the content of maleic acid and / or maleic anhydride is 0.01 to 10% by weight. , Preferably 0.05 to 5
% By weight. If the content is less than 0.01% by weight, the effect of improving the adhesive strength is reduced, while if it exceeds 10% by weight, the workability may be reduced.

The polymer according to the present invention comprises the above (A)
40% by weight of the ethylene-vinyl acetate copolymer (C)
As described above, it is preferable that the composition be contained in an amount of at least 60% by weight, and particularly be composed of only the ethylene-vinyl acetate copolymers (A) to (C). The polymer is ethylene-
When including a polymer other than the vinyl acetate copolymer, as the polymer other than the ethylene-vinyl acetate copolymer,
An olefin-based polymer containing 20 mol% or more of ethylene and / or propylene in the main chain, polyvinyl chloride,
Acetal resins and the like can be mentioned.

As a crosslinking agent for the polymer, an organic peroxide as a thermal crosslinking agent for forming a thermosetting adhesive layer, and as a photocrosslinking agent for forming a photocurable adhesive layer. Can be used.

Here, as the organic peroxide, any one can be used as long as it decomposes at a temperature of 70 ° C. or more to generate radicals, but a decomposition temperature having a half-life of 10 hours is 50 ° C. or more. The adhesive is preferably selected in consideration of the application temperature of the pressure-sensitive adhesive, preparation conditions, storage stability, curing (adhesion) temperature, heat resistance of the object to be adhered, and the like.

Examples of usable organic peroxides include, for example, 2,5-dimethylhexane-2,5-dihydroperoxide and 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne- 3, di-t-butyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane,
Dicumyl peroxide, α, α′-bis (t-butylperoxyisopropyl) benzene, n-butyl-4,
4′-bis (t-butylperoxy) valerate, 1,
1-bis (t-butylperoxy) cyclohexane,
1,1-bis (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, t-butylperoxybenzoate, benzoyl peroxide, t-butylperoxyacetate, methyl ethyl ketone peroxide, 2,5-dimethylhexyl-2,5-bisperoxybenzoate, butyl hydroperoxide, p-
Menthane hydroperoxide, p-chlorobenzoyl peroxide, hydroxyheptyl peroxide, chlorohexanone peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, cumyl peroxy octoate, succinic acid peroxide, acetyl peroxide Oxide, t-butyl peroxy (2-ethylhexanoate), m-toluoyl peroxide, t-butyl peroxyisobutyrate, 2,4-dichlorobenzoyl peroxide, and the like. As organic peroxides,
At least one of them is used alone or in combination, and usually 0.1 to 10% by weight is added to the polymer.

On the other hand, as the photosensitizer (photopolymerization initiator), a radical photopolymerization initiator is suitably used. Among the radical photopolymerization initiators, benzophenone, methyl o-benzoyl benzoate, 4-
Benzoyl-4′-methyldiphenyl sulfide, isopropylthioxanthone, diethylthioxanthone,
Ethyl 4- (diethylamino) benzoate and the like can be used. In addition, among the radical photopolymerization initiators, benzoin ether, benzoyl propyl ether, benzyl dimethyl ketal, α-hydroxyalkylphenone as an intramolecular cleavage type initiator, and 2-hydroxy-2-type as an α-hydroxyalkylphenone type.
Methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, alkylphenylglyoxylate, diethoxyacetophenone, and 2-methyl-1- [4- (methylthiophene) as α-aminoalkylphenone type )) Phenyl) -2-morpholinopropanone-1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1
But also acylphosphine oxide and the like. As the photosensitizer, at least one of them is used alone or in combination, and usually 0.1 to 10% by weight is added to the polymer.

The pressure-sensitive adhesive layer according to the present invention preferably contains a silane coupling agent as an adhesion promoter. As the silane coupling agent, vinyl triethoxy silane,
Vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl)-
one or two of γ-aminopropyltrimethoxysilane, etc.
Mixtures of more than one species are used. These silane coupling agents are generally used in an amount of about 0.01 to 10% by weight based on the polymer.

Further, an epoxy group-containing compound may be blended as an adhesion promoter. In this case, as the epoxy group-containing compound, triglycidyl tris (2-hydroxyethyl) isocyanurate, neopentyl glycol diglycidyl ether, , 6-hexanediol diglycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol (EO) ₅ glycidyl ether, p-
t-butylphenyl glycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester,
Glycidyl methacrylate, butyl glycidyl ether and the like can be mentioned. A similar effect can be obtained by alloying a polymer containing an epoxy group. These epoxy group-containing compounds may be used alone or in combination.
As a mixture of at least two or more kinds, usually 0.1 to 0.1% of the polymer is used.
About 1 to 20% by weight is used.

In order to improve or adjust the physical properties (mechanical strength, adhesiveness, optical properties, heat resistance, moisture resistance, weather resistance, crosslinking speed, etc.) of the pressure-sensitive adhesive layer or the adhesive layer, the pressure-sensitive adhesive layer includes A compound having an acryloxy group, a methacryloxy group or an allyl group can also be blended.

As the compound used for this purpose, acrylic acid or methacrylic acid derivatives such as esters and amides thereof are the most common, and the ester residue is an alkyl group such as methyl, ethyl, dodecyl, stearyl, lauryl. Cyclohexyl group, tetrahydrofurfuryl group, aminoethyl group, 2-hydroxyethyl group, 3-hydroxypropyl group, 3-chloro-2-
And a hydroxypropyl group. Further, esters with polyfunctional alcohols such as ethylene glycol, triethylene glycol, polypropylene glycol, polyethylene glycol, trimethylolpropane, and pentaerythritol are also used. As the amide, diacetone acrylamide is typical. Examples of the polyfunctional crosslinking assistant include acrylic acid or methacrylic acid ester such as trimethylolpropane, pentaerythritol and glycerin, and compounds having an allyl group include triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl isophthalate. , Diallyl maleate and the like. These compounds are usually used as one kind or as a mixture of two or more kinds,
0% by weight, preferably 0.5 to 30% by weight is used. If the amount exceeds 50% by weight, the workability and coatability during preparation of the pressure-sensitive adhesive may be reduced.

Further, a hydrocarbon resin can be added to the pressure-sensitive adhesive layer for the purpose of improving workability, bonding and the like.
In this case, the hydrocarbon resin to be added may be either a natural resin type or a synthetic resin type. Rosin as a natural resin system,
Rosin derivatives and terpene resins are preferably used. For rosin, gum-based resins, tall oil-based resins, and wood-based resins can be used. As the rosin derivative, rosin obtained by hydrogenation, heterogeneization, polymerization, esterification, and metal salification can be used. As the terpene-based resin, terpene-based resins such as α-pinene and β-pinene, as well as terpene phenol resins can be used. Further, dammar, koval, and shellac may be used as other natural resins. On the other hand, in the case of synthetic resins, petroleum resins, phenol resins, and xylene resins are preferably used.
Petroleum resins include aliphatic petroleum resins, aromatic petroleum resins,
Alicyclic petroleum resins, copolymer petroleum resins, hydrogenated petroleum resins, pure monomer petroleum resins, and cumarone indene resins can be used. As the phenolic resin, an alkylphenol resin and a modified phenol resin can be used. As the xylene-based resin, a xylene resin or a modified xylene resin can be used. The addition amount of these hydrocarbon resins is appropriately selected, but is preferably from 1 to 200% by weight, more preferably from 5 to 150% by weight, based on the polymer.

In addition to the above additives, in the present invention,
An antioxidant, an ultraviolet absorber, a dye, a processing aid, and the like may be incorporated in the pressure-sensitive adhesive layer within a range that does not impair the purpose of the present invention.

As the metal foil serving as the base material of the cross-linked conductive pressure-sensitive adhesive tape of the present invention, a foil of copper, silver, nickel, aluminum, stainless steel or the like can be used, and the thickness thereof is set to be a cross-linked conductive pressure-sensitive adhesive tape. Although it differs depending on the application, it is usually about 1 to 100 μm.

The pressure-sensitive adhesive layer is obtained by uniformly mixing the above-mentioned metal foil with the above-mentioned ethylene-vinyl acetate copolymer, a cross-linking agent and, if necessary, other additives and conductive particles at a predetermined ratio. It can be easily formed by coating with a roll coater, die coater, knife coater, my cover coater, flow coater, spray coater or the like.

The thickness of the pressure-sensitive adhesive layer is usually 5 to 10
It is about 0 μm.

The pressure-sensitive adhesive layer is usually provided on one side of the metal foil, but may be provided on both sides.

In order to apply the cross-linked conductive pressure-sensitive adhesive tape of the present invention to an object to be bonded, the cross-linked conductive pressure-sensitive adhesive tape is applied by utilizing the adhesiveness of the pressure-sensitive adhesive layer of the cross-linked conductive pressure-sensitive adhesive tape. It may be attached to the object to be worn (this temporary fixing may be re-attached if necessary), and then heated or irradiated with ultraviolet rays while applying pressure as needed. At the time of this ultraviolet irradiation, heating may be performed at the same time. In addition, by locally performing the heating or the light irradiation, it is possible to adhere only a part of the cross-linkable conductive adhesive tape.

In particular, the cross-linkable conductive pressure-sensitive adhesive tape of the present invention can be easily bonded with a general heat sealer. The method may be such that the object to be adhered is placed in a vacuum bag and degassed and then heated, and adhesion is easy.

As the bonding conditions, in the case of thermal crosslinking,
Although it depends on the type of the crosslinking agent (organic peroxide) to be used, it is usually 70 to 150 ° C, preferably 70 to 130 ° C, and usually 10 seconds to 120 minutes, preferably 20 seconds to 60 minutes.

In the case of photocrosslinking, the light source is ultraviolet to
Many light sources that emit light in the visible region can be used, and examples thereof include ultra-high pressure, high pressure, low pressure mercury lamps, chemical lamps, xenon lamps, halogen lamps, mercury halogen lamps, carbon arc lamps, incandescent lamps, and laser light.
The irradiation time is not generally determined depending on the type of the lamp and the intensity of the light source, but is usually several tens seconds to several tens of minutes. After heating to 40 to 120 ° C. in advance to promote crosslinking, ultraviolet rays may be applied to this.

The pressing force at the time of bonding is also appropriately selected, and is usually 0 to 50 kg / cm ² , particularly 0 to 30 kg / cm ² .
It is preferable that the pressure is set to cm ² .

By bonding by heating or light irradiation in this way, for example, as shown in FIG. 1 (a), the present invention forms an adhesive layer 3 in which conductive particles 2 are dispersed in a metal foil 1. Is pressed on a conductive film 7 having a transparent conductive layer 6 formed on a base film 5 while being cross-linked and cured, as shown in FIG. 1 (b). The transparent conductive layer 6 and the metal foil 1
Can be conducted.

The conductivity of the adhesive layer 8 is 10 Ω or less, particularly 5 Ω or less in the resistance value in the layer thickness direction.
The resistance in the plane direction is preferably 10 ⁶ Ω or more, particularly preferably 10 ⁹ Ω or more.

The crosslinked conductive pressure-sensitive adhesive tape of the present invention is
Assembling of electromagnetic wave shielding light transmitting window material for P, electromagnetic wave shielding light transmitting window material for PDP, electromagnetic wave shielding light transmitting window material for FED, electromagnetic wave shielding light transmitting window material for microwave oven, etc. Is industrially extremely useful for the formation of

[0043]

The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Example 1 A 15% by weight solution of an ethylene-vinyl acetate copolymer ("Ultracene 710" manufactured by Tosoh Corporation) having a vinyl acetate content of 28% by weight was prepared. , 1,1-bis (t-butylperoxy)-
0.5% by weight of 3,3,5-trimethylcyclohexane, 2.0% by weight of glycidyl methacrylate, and 0.5% by weight of γ-methacryloxypropyltrimethoxysilane were added and mixed well. Further, 4% by volume of a spherical copper particle (3.8 μm in particle diameter) manufactured by Fukuda Metal Foil Powder Co., Ltd. was mixed with the ethylene-vinyl acetate copolymer, and this was mixed with a bar coater into an aluminum foil having a width of 250 mm and a thickness of 15 μm. It was applied to form an adhesive layer having a thickness of 25 μm.

As shown in FIG. 1, this cross-linkable conductive pressure-sensitive adhesive tape was formed on a conductive film (a base film made of a polyester film having a thickness of 125 μm, a transparent conductive layer made of an indium tin oxide layer having a thickness of 0.1 μm). At 130 ° C. and 10 kg / cm ² .
The thermocompression bonding was performed for 0 minutes.

The conduction resistance in the thickness direction and the insulation resistance and the adhesion strength in the plane direction of the adhesive layer between the aluminum foil of the cross-linked conductive adhesive tape of the joined body and the transparent conductive layer of the transparent conductive film are determined by:
The measurement was performed immediately after the bonding and after the elapse of time (leaving at 80 ° C. for 500 hours). The results are shown in Table 1.

Example 2 A 15% by weight toluene solution of an ethylene-vinyl acetate copolymer ("Ultracene 750" manufactured by Tosoh Corporation, vinyl acetate content: 32% by weight) was prepared. Benzoyl peroxide, 4.0% by weight of glycidyl methacrylate, and 0.5% by weight of γ-methacryloxypropyltrimethoxysilane, and thoroughly mixed. Further, the same as Example 1 except that the pressure-sensitive adhesive layer was formed by mixing 4% by volume of spherical nickel particles (particle size: 7.6 μm) manufactured by Fukuda Metal Foil Powder Industry with respect to the ethylene-vinyl acetate copolymer. To produce a cross-linked conductive pressure-sensitive adhesive tape, and its performance was evaluated in the same manner. The results are shown in Table 1.

Examples 3 to 8 According to the method described in Example 1, the components shown in Tables 1 and 2 were used in the proportions shown in Tables 1 and 2 to produce cross-linked conductive pressure-sensitive adhesive tapes. The conductive films were adhered by the methods shown in Tables 1 and 2, and the performance was evaluated in the same manner.
2 is shown.

The details of the components and bonding methods described in Tables 1 and 2 are as follows.

The amount of the conductive particles is the volume% based on the ethylene-vinyl acetate copolymer, and the amount of each component other than the conductive particles is the weight% based on the ethylene-vinyl acetate copolymer.

Ethylene-vinyl acetate copolymer A: "Ultracene 710" manufactured by Tosoh Corporation Ethylene vinyl acetate copolymer (vinyl acetate content: 28% by weight) Ethylene-vinyl acetate copolymer B: manufactured by Tosoh Corporation Ultracene 750 "ethylene-vinyl acetate copolymer (vinyl acetate content 32% by weight) Ethylene-vinyl acetate copolymer C:" Ultracene 760 "ethylene-vinyl acetate copolymer manufactured by Tosoh Corporation (vinyl acetate content 42% by weight) %) Ethylene-vinyl acetate copolymer D: "Bond First 2A" manufactured by Sumitomo Chemical Co., Ltd. Ethylene-vinyl acetate-glycidyl methacrylate copolymer (vinyl acetate content 8% by weight, glycidyl methacrylate content 3% by weight) ethylene -Vinyl acetate copolymer E: "M" manufactured by Mitsubishi Chemical Corporation
ODIC E-100H "ethylene-vinyl acetate-maleic anhydride copolymer (vinyl acetate content 20% by weight, maleic anhydride content about 0.5% by weight) Organic peroxide a: 1,1-bis (t -Butylperoxy) -3,3,5-trimethylcyclohexane Organic peroxide b: benzoyl peroxide Photosensitizer: benzoylpropyl ether Silane coupling agent: γ-methacryloxypropyltrimethoxysilane Epoxy group-containing compound: glycidyl Methacrylate Acryloxy group-containing compound: triallyl isocyanurate Hydrocarbon resin: "Arucon P70" manufactured by Arakawa Chemical Industries Conductive particle Cu: Spherical copper particle manufactured by Fukuda Metal Foil Powder Industry Conductive particle Ni: True spherical manufactured by Fukuda Metal Foil Powder Industry nickel particles adhering method I: 130 ° C. heating, 5 minutes 10 kg / cm ² pressure Lifting (I '10 minute hold under the same conditions) METHOD adhesive II: 5kg / cm ² after pressing, the pressure was released, U
Irradiation with UV light by a V lamp for 30 seconds Tables 1 and 2 also show the MFR of the polymer of the pressure-sensitive adhesive layer.

[0052]

[Table 1]

[0053]

[Table 2]

Comparative Example 1 A 15% by weight solution of an epoxy resin in toluene was prepared, and 4% by volume of spherical copper particles (3.8 μm in diameter) manufactured by Fukuda Metal Foil & Powder Co., Ltd. were mixed with the epoxy resin. Was applied to a metal foil using a bar coater in the same manner as in Example 1 to obtain a conductive tape.

This tape was heated at 170 ° C. and 10 kg / c.
By holding the m ² under pressure for 20 minutes, it adheres to the conductive film in the same manner as in Example 1, and performs the performance evaluation in the same manner.
The results are shown in Table 3.

Comparative Example 2 A 15% by weight solution of a phenolic resin in toluene was prepared.
Spherical nickel particles made by Fukuda Metal Foil Powder Industry (particle size 7.6μ
m) was mixed at 4% by volume with respect to the phenolic resin, and the mixture was applied to a metal foil using a bar coater in the same manner as in Example 1 to obtain a conductive tape.

This tape was heated at 170 ° C. and 10 kg / c.
By holding the m ² under pressure for 20 minutes, it adheres to the conductive film in the same manner as in Example 1, and performs the performance evaluation in the same manner.
The results are shown in Table 3.

[0058]

[Table 3]

From Tables 1 to 3, it can be seen that the cross-linked conductive pressure-sensitive adhesive tape of the present invention is superior to conventional conductive tapes in adhesive strength, conductivity and durability.

Incidentally, all of the samples of Examples 1 to 8 could be peeled off very easily with a solvent such as acetone or toluene after bonding.

[0061]

As described in detail above, according to the present invention, since the adhesive strength of the adhesive layer is high, the long-term durability, particularly, the moisture resistance is excellent, and the adhesive layer has an appropriate adhesive strength, it is possible to temporarily fix and reattach. A cross-linked conductive pressure-sensitive adhesive tape which is possible and has excellent adhesive workability is provided.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a method for attaching a cross-linked conductive pressure-sensitive adhesive tape of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal foil 2 Conductive particle 3 Adhesive layer 4 Crosslinked conductive adhesive tape 5 Base film 6 Transparent conductive layer 7 Conductive film 8 Adhesive layer

Claims (3)

[Claims] 1. A cross-linked conductive pressure-sensitive adhesive tape comprising a metal foil provided on at least one surface with a pressure-sensitive adhesive layer in which conductive particles are dispersed, wherein the pressure-sensitive adhesive layer comprises an ethylene-vinyl acetate copolymer. A cross-linked conductive pressure-sensitive adhesive tape, which is a post-cross-linked adhesive layer containing a polymer containing a polymer as a main component and a cross-linking agent thereof. 2. The ethylene-vinyl acetate copolymer according to claim 1, wherein the ethylene-vinyl acetate copolymer has (A) a vinyl acetate content of 20 to 8;
0% by weight of an ethylene-vinyl acetate copolymer, (B)
A copolymer of ethylene, vinyl acetate, acrylate and / or methacrylate monomer having a vinyl acetate content of 20 to 80% by weight and an acrylate and / or methacrylate monomer content of 0.01 to 10% by weight. The polymer, and (C) a vinyl acetate content of 20 to 80% by weight and a content of maleic acid and / or maleic anhydride of 0.01 to 10% by weight, ethylene, vinyl acetate, maleic acid and / or Or a cross-linked conductive pressure-sensitive adhesive tape, which is one or more selected from the group consisting of a copolymer with maleic anhydride. 3. The cross-linking agent according to claim 1, wherein the cross-linking agent is an organic peroxide or a photosensitizer, and the content of the cross-linking agent to the polymer in the pressure-sensitive adhesive layer is 0.1 to 10% by weight. A cross-linkable conductive pressure-sensitive adhesive tape,