JP2020064889A - Wiring sheet - Google Patents

Abstract

To provide a flexible wiring sheet that conductively joins between printed flexible wiring by a simple method or between a printed flexible wiring and a flexible metal wiring and simultaneously exhibits high sealing performance.SOLUTION: A wiring sheet includes a sheet-shaped substrate (1), first conductive wiring (2) arranged on the sheet-shaped substrate, a film protective layer (3) that protects the first conductive wiring, and second conductive wiring (4) connected to the first conductive wiring (2), and the first conductive wiring (2) and the second conductive wiring (4) are connected by a conductive adhesive (6) containing metal or carbon, and the connecting portion is sealed with a sealing material (7).SELECTED DRAWING: Figure 1

Description

    The present invention relates to a joining method for easily joining flexible wiring and having long-term reliability.

In the field of electronic devices, as a method for joining rigid wiring boards, a rigid flexible board (Patent Document 1) in which a flexible board is incorporated in an inner layer, connection through a connector, and a method of joining wiring boards with an anisotropic conductive material (Patent Document 2) or the like is adopted, but in the case of 1, complicated processes such as a thermocompression bonding process through a prepreg for pattern formation by etching or a multilayer structure are required, and 2 anisotropic conductive materials are used. The joining is expensive, and the connection strength is insufficient in applications where physical stress is repeatedly applied such as in biosensors. As a construction method for such a problem, there has been proposed a joining method between electrodes by soldering and a joining method in which a thermosetting resin is filled therebetween (Patent Document 3), but a physical stress is always applied to a flexible base material. Solder joining is insufficient at the place, and a material such as a PET substrate suitable for forming a circuit in printing cannot withstand the high temperature at the time of solder joining.
2. Description of the Related Art In recent years, a wearable device that is worn on the body and acquires a biomedical signal requires a flexible hybrid material that uses a flexible wiring and a rigid substrate such as an IC module together. How to bond the wiring material by printing on the base material that does not have heat resistance such as PET and the wiring from the rigid member is a big issue, and it is a joining technology that has a joint reliability that can be used practically, and is lightweight and simple. It is the actual situation that has not been obtained yet.

JP2012-114482A JP2012-174589 JP 2014-183087

  It is an object of the present invention to provide a flexible wiring sheet that electrically conductively bonds between printed flexible wirings or between printed flexible wirings and flexible metal wirings by a simple method and simultaneously exhibits high sealing performance.

The present inventor has conducted extensive studies to solve the above-mentioned problems, and as a result, conductively joins flexible circuits with a conductive adhesive, and the peripheral portion thereof is simply joined with a hot melt adhesive or a thermosetting adhesive. In addition, the present invention has been completed as a wiring sheet that seals a conductive joint portion.

  The present invention is to bond a flexible printed wiring by printing or between a printed flexible wiring and a flexible metal wiring with a conductive adhesive and at the same time seal the periphery thereof with a sealing material composition, so that the bonded portion is against physical stress. By developing the resistance and at the same time the high sealing property under the high temperature and high humidity environment, the long-term reliability of the wiring is secured.

  That is, the present invention provides a sheet-shaped base material (1), a first conductive wiring (2) arranged on the sheet-shaped base material, and a film protective layer (3) for protecting the first conductive wiring. ) And a second conductive wiring (4) connected to the first conductive wiring (2), the first conductive wiring (2) and the second conductive wiring (2). (4) is connected with a conductive adhesive (6) containing a metal or carbon, and the connection part is sealed with a sealing material (7).

  The present invention also relates to the above wiring sheet, wherein the first conductive wiring (2) is a printed conductive wiring.

  The present invention also relates to the above wiring sheet, wherein the encapsulant is made of a hot melt adhesive composition containing a styrene copolymer.

  Further, the present invention, the styrene-based copolymer is at least selected from the group consisting of styrene-isoprene copolymer, hydrogenated styrene-isoprene copolymer, styrene-butadiene copolymer, and hydrogenated styrene-butadiene copolymer. The present invention relates to the above wiring sheet, which contains one type.

  The present invention also relates to the above wiring sheet, wherein the hot melt adhesive composition further contains a tackifying resin.

  Further, in the present invention, the mass ratio of the styrene copolymer and the tackifying resin in the hot melt adhesive composition is such that the mass of the styrene copolymer: the mass of the tackifying resin = 30: 70 to 100: 0. The present invention relates to the above wiring sheet.

  The present invention also relates to the above wiring sheet, wherein the encapsulant comprises a thermosetting adhesive composition containing at least one selected from the group consisting of acrylic resin, urethane resin, and polyamide resin.

  The present invention also relates to the above wiring sheet, wherein the sheet-shaped substrate (1) is PET (polyethylene terephthalate), PEN (polyethylene naphthalate) or PVC (polyvinyl chloride).

  INDUSTRIAL APPLICABILITY According to the present invention, printed flexible conductive wirings, or printed flexible conductive wirings and flexible metal wirings can be easily bonded, and the conductive bonding portion is broken even when moved during use. A strong and long-term reliable coupling wiring can be achieved.

Shows an example of the structure of the laminate of the present invention. Shows a method for producing a wiring sheet in Examples "wiring sheet adhesion test" and "wiring sheet bending test". Shows the tensile test method in the example "wiring sheet adhesion test". Shows the expansion / contraction test method in the example "wiring sheet bending test". Shows a method for producing a wiring sheet in the example "long-term reliability test".

  In the wiring sheet of the present invention, the first conductive wiring (2) printed on the sheet-shaped base material (1) and the film protective layer (3) for protecting the first conductive wiring are the same as those in the above (2). A first opening for exposing the conductive wiring is provided, the conductive adhesive (6) is disposed in the first opening, and the encapsulant is provided around the first opening. The first conductive wiring (2) and the second conductive wiring (4) are arranged and connected by the conductive adhesive (6), and the first film protective layer (around the connection portion) ( 3) and the second conductive wiring are joined by a sealing material. (Fig. 1)

<Sealing material>
The sealing material of the present invention may be a sheet or a liquid agent. In the case of a sheet, a sealing sheet is arranged around the opening of the first conductive wiring (1) and the second conductive wiring (2), and the conductive adhesive (6) is used to form the first conductive wiring. At the time of joining (1) and the second conductive wiring (2), the sealing material is joined by pressure bonding or thermocompression bonding. In the case of a liquid agent, a liquid sealing material is applied to the opening of the first conductive wiring (1) and the peripheral portion of the second conductive wiring (2), and the first conductive adhesive (6) is used to apply the liquid sealing material. When the conductive wiring (1) and the second conductive wiring (2) are bonded, they are pressure-bonded. The hot-melt type encapsulant is solid at room temperature, but is applied in a state of being heated and melted by a hot-melt gun in the same manner as above. When the second conductive wiring is a metal cord, after setting the second metal cord in the opening of the first conductive wiring, conductive bonding is performed with a conductive adhesive, and a sealing material is applied to the sheet base material. After arranging the product coated with the above so as to cover the entire bonding surface, the bonding and sealing are completed by heating and pressure bonding with a hot iron or a heat roll.

As the sealing material of the present invention, a hot-melt adhesive composition containing a styrene-based copolymer or a thermosetting adhesive composition containing an acrylic resin, a urethane resin or a polyamide resin is preferable.

(Hot melt adhesive composition)
The hot melt adhesive composition of the present invention comprises a thermoplastic resin, a tackifying resin and a softening agent, an antioxidant and other optional components used as necessary.

  The thermoplastic resin may be a so-called hot melt resin that is a non-curable resin that becomes flowable at high temperature and returns to a non-flowable state by cooling.

  Thermoplastic resins include polyurethane-based, acrylonitrile-based, diene-based, acrylic-based, butadiene-based, polyamide-based, polyvinyl butyral-based, olefin-based, isoprene-based, butadiene-based, chloroprene-based, acrylonitrile-based, polyester-based, polyvinyl chloride-based, One or more selected from the group consisting of a styrene type, an ethylene-vinyl acetate type, a fluorine type, a silicone type, a thermoplastic resin containing a copolymer thereof, and the like can be included. However, it is not limited to these resins. From the viewpoint of durability, weather resistance, heat resistance and adhesive strength, the thermoplastic resin more preferably contains a styrene-based thermoplastic resin. The thermoplastic resins may be used alone or in combination of two or more. Further, as the thermoplastic resin, a copolymer formed by connecting different monomers may be used.

A styrene-based thermoplastic resin, more specifically, a styrene-based elastomer, generally has a polystyrene block and a rubber intermediate block, and the polystyrene portion forms a physical crosslink (domain) to serve as a bridge point, and an intermediate The rubber block gives rubber elasticity to the product. In the middle soft segment, there are polybutadiene (B), polyisoprene (I) and polyolefin elastomer (ethylene propylene, EP), and depending on the arrangement of the hard segment polystyrene (S), linear (linear type) And radial (radical type). Among the preferable styrene elastomers described above, more specifically in the present invention, styrene isoprene styrene block copolymer (SIS), styrene / ethylene / butylene / styrene block copolymer hydrogenated product (SEPS), styrene / butylene Styrene block copolymer (SBS), hydrogenated styrene / ethylene / butylene / styrene block copolymer (SEBS), styrene / butadiene / isoprene / styrene block copolymer (SBIS) or styrene / butadiene / isoprene / styrene One or more kinds selected from the group consisting of hydrogenated block copolymers (SEEPS) can be contained. However, it is not limited to these resins.

The tackifying resin is a resin component that improves tackiness by being mixed with a thermoplastic resin having poor tackiness.

Examples of the tackifying resin include hydrogenated terpene resin, terpene resin, hydrogenated rosin resin, rosin resin, hydrogenated hydrocarbon resin, epoxy resin, hydrogenated epoxy. -Based resin, ketone-based resin, hydrogenated ketone-based resin, polyamide-based resin, hydrogenated polyamide-based resin, elastomer-based resin, hydrogenated elastomer-based resin, phenol-based resin, hydrogenated phenol-based resin , Petroleum-based resins, hydrogenated petroleum-based resins, styrene-based resins, and hydrogenated styrene-based resins. These tackifying resins may be used alone or in combination of two or more.
Of these, hydrogenated hydrocarbon resins are preferable from the viewpoint of durability. Since hydrogenation eliminates the conjugated double bond in the intramolecular structure, the hot melt adhesive containing the tackifying resin is less prone to deterioration due to light or heat when adhered to the adherend for a long period of time of 10 years or more. Adhesive strength can be maintained.

  In the present invention, the hot melt adhesive composition contains the styrene-based thermoplastic resin in an amount of 30 to 100% by weight and the tackifying resin in an amount of 0 to 70% by weight. Preferably, the styrene-based thermoplastic resin is in the range of 30 to 50% by weight and the tackifying resin is in the range of 50 to 70% by weight.

The softening agent is used as necessary when imparting fluidity and tackiness when the hot melt adhesive composition is heated. Examples of the softening agent include petrolatum, mineral oil, vegetable fats and oils, animal fats and oils. As the mineral oil, liquid paraffin, paraffin, paraffinic mineral oil having a paraffin chain carbon number of 50% or more of the total carbon number, naphthene type mineral oil having a naphthene ring carbon number of 30 to 40% by weight of the total carbon number, And aromatic mineral oils having an aromatic carbon number of 30% by weight or more of the total carbon number. Vegetable oils and fats: olive oil, carnauba wax, rice germ oil, corn oil, southern oil, camellia oil, castor oil, jojoba seed oil, mink oil, eucalyptus leaf oil and the like. Animal fats and oils: Beeswax, squalane, honey can be mentioned. Others, mistylic acid, oleic acid, isopropyl mytylate, zinc mystylate, octyldodecyl myristate, glyceryl triisooctanoate, octyldodecanol, hexyldecanol, diisopropyl adipate, diethyl sebacate, stearic acid, isostearic acid, crotamiton, medium chain Fatty acid triglycerides, ethylene glycol salicylate, cetyl ethylhexanoate, glycol distearate, cetearyl alcohol, cetanol, cetyl palmitate, ethylhexyl palmitate, isopropyl palmitate, behenyl alcohol and the like can also be used as the softening agent. These softening agents may be used alone or in combination of two or more.

The antioxidant is used because the oxidation does not proceed with heating during the production of the hot melt adhesive composition or when it is used as a sealing material. Examples of the antioxidant include pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-t-butyl-4-). Hydroxyphenyl) propionate, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphonate, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxy) Ethylene) bis [3- (5-t-butyl-4-hydroxy-m-tolyl] propionate, tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-di-t-butyl) Phenyl) pentaerythritol diphosphite, etc. Phenolic antioxidants include pentaerythritol tet Lakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] is preferable, and the phosphorus-based antioxidant is preferably tris (2,4-di-t-butylphenyl) phosphite.

The hot-melt adhesive composition of the present invention can appropriately contain various additives as long as the effects of the present invention are not impaired. For example, an organic or inorganic filler can be blended from the viewpoint of curing shrinkage reduction, thermal expansion coefficient reduction, dimensional stability improvement, elastic modulus improvement, viscosity adjustment, strength improvement and toughness improvement. Such filler may be composed of materials such as polymers, ceramics, metals, metal oxides, metal salts, dyes and pigments. Further, the shape thereof is not particularly limited, and may be, for example, a particulate shape or a fibrous shape. In addition, in order to adjust the leveling and coating properties with the substrate and improve the adhesiveness, silane coupling agents, titanate coupling agents, flame retardants, storage stabilizers, antioxidants, metal deactivation Agents, ultraviolet absorbers, thixotropy imparting agents, leveling agents, defoaming agents, dispersion stabilizers, fluidity imparting agents, defoaming agents and coloring materials can also be added. Also, a solvent may be included in order to improve the fluidity.

The hot-melt adhesive composition of the present invention comprises the above-mentioned thermoplastic elastomer resin and tackifying resin as main components, and after addition of a softening agent, tackifying agent, antioxidant and other components, if necessary. It can be manufactured by uniformly dispersing. A heat-melting adhesive prepared by heating and mixing the mixture by using a roll, a Banbury mixer, a kneader, a melting pot equipped with a stirrer, or a single-screw or twin-screw extruder, etc., and stirring after dissolving in a suitable solvent It can be obtained by using a solvent-type adhesive formed by mixing.

The hot melt adhesive can be produced by melting and kneading the hot melt adhesive composition at a high temperature of 150 ° C. or higher. On the other hand, the solvent-type adhesive obtains a uniform solution by dissolving the hot-melt adhesive composition in a solvent and stirring and mixing it. The solvent used is not particularly limited as long as it dissolves the thermoplastic resin and the hot melt adhesive composition. Of the thermoplastic elastomers, if they could not be melt-mixed with the tackifier or other components even when heated to 200 ° C., they were deemed not suitable for sheet formation.
The hot-melt adhesive composition used in the present invention is preferably a heat-melting adhesive that does not use a solvent, from the viewpoint of complicating the process by removing the solvent and increasing the cost associated therewith, and from the viewpoint of adversely affecting the global environment by using the solvent. .

(Hot melt adhesive sheet)
The hot-melt adhesive of the present invention may be applied by directly heating the solid hot-melt adhesive at room temperature with a hot-melt gun and directly coating it on the base material of the wiring sheet. Alternatively, it can be manufactured as a hot-melt adhesive sheet which is applied and printed in a film form on a base film and then sandwiched with a release film.
The method of coating / printing the hot melt adhesive composition is not particularly limited. As a coating method, slot spray coating method, Omega coating method, spiral coating method, control seam coating method, slot spray coating method, dot coating method, hot melt applicator coating method, hot melt coater coating method, blade coat coating method, dip Coating method, gravure coat coating method, curtain spray coating method, bead coating method, hot melt roll coater spin coat coating method can be mentioned. Printing methods include inkjet printing method, spray printing method, roll coating printing method, doctor roll printing method. A doctor blade printing method, a curtain coating printing method, a slit coating printing method, a screen printing method, a reverse printing method, a push coat printing method, a slit coater printing method and the like. The drying conditions when a solvent is used are not particularly limited, and examples thereof include hot air drying, infrared rays, and a method using a reduced pressure method. As drying conditions, hot air heating at about 60 to 130 ° C. is usually used, though it depends on the film thickness and the selected organic solvent. The thickness of the hot melt composition is preferably 100 to 300 μm.

<Thermosetting adhesive composition>
The sealing material of the present invention is preferably sealed with a composition of a thermosetting adhesive selected from the group consisting of adhesives containing acrylic resin, urethane resin and polyamide resin.

The thermosetting adhesive is thermally polymerized at the time of synthesis, but is softened by thermocompression bonding so that the protective film layer (3) of the first conductive wiring sheet (2) and the second conductive wiring (4). Can be joined.
<Acrylic resin composition>
The acrylic resin composition is a pressure-sensitive adhesive resin adhesive containing an acrylic copolymer (f) and a cross-linking agent (C) described below as main components. As a form, a method of applying a pressure-sensitive adhesive to a release film, drying it, and then sandwiching it with a release film to prepare a pressure-sensitive adhesive sheet, or a method of directly printing on a wiring sheet to seal the conductive coupling part can also be used. . When forming a sheet, a double-sided tape can be prepared by laminating an adhesive on both sides of a plastic substrate.
<Acrylic resin>
The acrylic resin is an acrylic copolymer (f) and is obtained from an acrylic copolymer having a hydroxyl group or an acrylic copolymer having no hydroxyl group.

The acrylic copolymer (A) is obtained by copolymerizing a monomer having a hydroxyl group or another monomer having no hydroxyl group. That is, the acrylic copolymer is a copolymer composed of a unit derived from a monomer having a hydroxyl group and a unit derived from another monomer.

  Examples of the monomer having one hydroxyl group include hydroxyalkyl (meth) acrylate and compounds obtained by adding ε-caprolactone to the hydroxyalkyl (meth) acrylate, and hydroxyalkyl (meth) acrylate is preferable.

Specific examples of hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Examples thereof include hydroxyalkyl (meth) acrylates having an alkyl group having 1 to 4 carbon atoms such as hydroxybutyl (meth) acrylate.
Specific examples of the compound obtained by adding ε-caprolactone to hydroxyalkyl (meth) acrylate include 1 mol of ε-caprolactone of 2-hydroxyethyl (meth) acrylate and 2 mol of ε-caprolactone of 2-hydroxyethyl (meth) acrylate. Examples of the adduct include an ε-caprolactone adduct of a hydroxyalkyl (meth) acrylate having 1 to 4 carbon atoms such as an adduct, an ε-caprolactone 3 mol adduct of 2-hydroxyethyl (meth) acrylate, and the like. The present invention is not limited to this example. These hydroxyl group-containing monomers may be used alone or in combination.

  Examples of the monomer having two or more hydroxyl groups include 1,1-dihydroxymethyl (meth) acrylate, 1,2-dihydroxyethyl (meth) acrylate, 2,2-dihydroxyethyl (meth) acrylate and 2,3- Dihydroxypropyl (meth) acrylate or a (meth) acryloyl-based monomer having an epoxy group in one molecule is reacted with a compound having one functional group capable of reacting with an epoxy group in one molecule and a hydroxyl group, or water, Examples thereof include monomers obtained by ring opening of an epoxy group, but the present invention is not limited to such examples. These hydroxyl group-containing monomers may be used alone or in combination.

  Examples of other acrylic-based monomers having no hydroxyl group include the following various monomers. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth). Acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, Examples thereof include alkyl (meth) acrylates such as tert-butylhexyl (meth) acrylate, 2-acetoacetoxyethyl (meth) acrylate, and phenoxyethyl (meth) acrylate.

  Examples of the monomer having an alicyclic hydrocarbon group include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, Examples thereof include dicyclopentenyl (meth) acrylate and dicyclopentanyl (meth) acrylate.

  Examples of the monomer having an epoxy group include glycidyl (meth) acrylate, α-methylglycidyl acrylate, α-methylglycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, and 3,4-epoxycyclohexylmethyl methacrylate.

  The acrylic copolymer (A) having a hydroxyl group is preferably one obtained by polymerizing a methacrylate-based monomer among the various monomers described above.

  Examples of the method for polymerizing the monomer include a solution polymerization method, a bulk polymerization method, a suspension polymerization method and an emulsion polymerization method, but the present invention is not limited to such a polymerization method. Among these polymerization methods, the solution polymerization method is preferable because the resulting reaction mixture can be used as it is.

  One embodiment of the case where the acrylic copolymer (A) having a hydroxyl group is prepared by solution polymerization of a monomer will be described below. However, the present invention is not limited to the embodiment.

  Examples of the solvent used for solution polymerization of the monomers include aromatic solvents such as toluene and xylene; alcohol solvents such as n-butyl alcohol, propylene glycol monomethyl ether, diacetone alcohol, and ethyl cellosolve; ethyl acetate; Examples of the solvent include ester solvents such as butyl acetate and cellosolve acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; and dimethylformamide, but the present invention is not limited thereto. It is preferable to appropriately determine the amount of the solvent according to the concentration of the monomer mixture, the molecular weight of the target acrylic copolymer, and the like.

  Examples of the polymerization initiator include 2,2′-azobis- (2-methylbutyronitrile), tert-butylperoxy-2-ethylhexanoate, 2,2′-azobisisobutyronitrile, benzoyl. Examples thereof include peroxide and di-tert-butyl peroxide, but the present invention is not limited to such examples. The amount of the polymerization initiator is usually preferably 0.01 to 30 parts by mass, more preferably 0.05 to 10 parts by mass, per 100 parts by mass of the monomer mixture. When the mass average molecular weight (Mw) is 100,000 or more as in the present invention, the amount of the polymerization initiator is preferably 0.05 to 0.1 part by mass.

  Since the polymerization time of the monomer varies depending on the polymerization temperature, the composition of the monomer mixture, the type and amount of the polymerization initiator, etc., it cannot be unconditionally determined. Therefore, it is preferable to appropriately determine the polymerization time.

The acrylic copolymer (A) may have an acid value. Since the reaction between the hydroxyl group and the isocyanate is promoted by having the acid value, a cured film having high durability can be obtained. When imparting an acid value, the acid value of the acrylic copolymer (A) is preferably 20 mgKOH / g or less. When the acid value is 20 mgKOH / g or less, durability can be imparted. The acid value is more preferably 15 mgKOH / g or less.
A method for imparting an acid value to the acrylic copolymer (A) is obtained by copolymerizing a monomer having an acid value with another monomer. Examples of the monomer having an acid value include (meth) acrylic acid, maleic anhydride, 2- (meth) acryloyloxyethyl-succinic acid, 2- (meth) acryloyloxyethyl-hexahydrophthalic acid, 2- (meth ) Acryloyloxyethyl-phthalic acid, 2- (meth) acryloyloxyethyl acid phosphate and the like are mentioned, and among them, (meth) acrylic acid is preferably used.

  The acrylic copolymer (A) preferably has a glass transition temperature of -70 to 50 ° C. When the glass transition temperature is −70 ° C. or higher, the adhesion to the substrate is obtained, and when it is 50 ° C. or lower, good flexibility is obtained. The glass transition temperature of the acrylic copolymer (A) is determined by the composition ratio of the monomer containing the hydroxyl group and the monomer containing the acidic functional group.

The copolymer (A) can be obtained by a known method, for example, solution polymerization. Examples of the solvent include alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether, and diethylene glycol methyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether. It is possible to use ethers, hydrocarbons such as hexane, heptane and octane, aromatics such as benzene, toluene, xylene and cumene, and esters such as ethyl acetate and butyl acetate. Two or more kinds of solvents may be mixed and used.
The charged concentration of the monomer during synthesis is preferably 0 to 80% by weight.
As the polymerization initiator, a peroxide or an azo compound, for example, benzoyl peroxide, azoisobutylvaleronitrile, azobisisobutyronitrile, di-t-butylperoxide, t-butylperbenzoate, t-butylperoctoate, Cumene hydroxyperoxide and the like can be used, and the polymerization temperature is preferably 40 to 200 ° C, particularly preferably 40 to 140 ° C.
The polystyrene-equivalent weight average molecular weight of the copolymer (A) is preferably 5,000 to 800,000, more preferably 10,000 to 100,000.

Alternatively, the copolymer (A-1) and the copolymer (A-2) may be separately produced and mixed to obtain the copolymer (A-1). After that, the monomer can be polymerized in the presence of the obtained copolymer to obtain the copolymer (A-2).

  The copolymer in that case has a high molecular weight component (A-1) and a low molecular weight component (A-2), and in the emission curve of GPC, it is 2 on the boundary of the minimum value (valley) on the emission curve. Showing two peaks, the weight average molecular weight of the high molecular weight component (A-1) obtained by dividing the two at valleys is used as the copolymer (A-1), and the weight average molecular weight of the low molecular weight component (A-2) is calculated. The copolymer (A-2) is prepared. Further, the area ratio of the high molecular weight component (A-1) / low molecular weight component (A-2) divided at the valley portion is the acrylic resin (A-1) and the acrylic resin (A-2) is the weight ratio. To do.

The cross-linking agent (C) that constitutes the acrylic resin composition of the present invention has a functional group capable of reacting with at least one of a carboxyl group and a hydroxyl group that the acrylic resin has. Examples of the crosslinking agent (C) include isocyanate compounds, epoxy compounds, metal chelate compounds, aziridine compounds, amine compounds, carbodiimide compounds, oxazoline compounds, and melamine compounds. By using the crosslinking agent, the cohesive force of the pressure-sensitive adhesive layer can be further improved. These crosslinking agents may be used alone or in combination of two or more.

Here, examples of the isocyanate compound include aromatic polyisocyanate, aliphatic polyisocyanate, araliphatic polyisocyanate, alicyclic polyisocyanate, and the like.
As the aromatic polyisocyanate, 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tridiene isocyanate Diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 " -Triphenylmethane triisocyanate and the like can be mentioned.
Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate. , 2,4,4-trimethylhexamethylene diisocyanate and the like.
Examples of the araliphatic polyisocyanate include ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene, 1 , 4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate, etc. can be mentioned.
Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl- 2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanatomethyl) cyclohexane and the like can be mentioned.

Further, the polyisocyanate can be modified to be used as a multimer such as a trimethylolpropane adduct body or an isocyanurate trimer.
Further, polyphenylmethane polyisocyanate (PAPI), naphthylene diisocyanate, and modified products of these polyisocyanates may be used. As the modified polyisocyanate, a carbodiimide group, a uretdione group, a uretoimine group, a buret group reacted with water, an isocyanurate group, or a modified product having two or more kinds of these groups can be used. Reaction products of polyols and diisocyanates can also be used as polyisocyanates.
Examples of these polyisocyanate compounds include 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), xylylene diisocyanate, 4,4'-methylenebisisate. From the viewpoint of weather resistance, it is particularly preferable to use a non-yellowing type or hardly yellowing type polyisocyanate compound such as (cyclohexyl isocyanate) (hydrogenated MDI).

Examples of the epoxy compound include bisphenol A-epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diester. Glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, N, N, N ', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N'-diglycidylaminomethyl) cyclohexane And so on.

Examples of the metal chelate compound include a chelate compound composed of acetylacetone or an acetonate ester of a divalent or higher metal such as aluminum, copper, iron, tin, zinc, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium. Can be mentioned.

Examples of the aziridine compound include trimethylolpropane-tri-β-aziridinylpropionate, bisisophthaloyl-1- (2-methylaziridine) and the like.

As the amine compound, any polyamine having two or more primary amino groups can be used without particular limitation. From the viewpoint of excellent curing speed, a polyamine having two or more primary amino groups that are not directly bonded to an aromatic ring, that is, a primary amino group is directly bonded to an aliphatic functional group or an alicyclic functional group. Aliphatic polyamines are preferred. The aliphatic polyamine may include an aromatic ring in its skeleton as long as the aromatic ring is not directly bonded to the primary amino group.

Examples of the aliphatic polyamine include 2,5-dimethyl-2,5-hexamethylenediamine, menthenediamine, 1,4-bis (2-amino-2-methylpropyl) piperazine, and propylene branched carbon at both ends of the molecule. Amino group-bonded polypropylene glycol [diamine having a propylene skeleton, for example, "Jefamine D230" and "Jeffamine D400" manufactured by San Techno Chemical Co., and triamine having a propylene skeleton, such as "Jeffamine T403". ], Ethylenediamine, propylenediamine, butylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, trimethylhexamethylenediamine, N-aminoethylpiperazine, 1,2-diaminopropane, iminobispropyl Diamine having a polyether skeleton in which a methylene group is bonded to an amine nitrogen such as amine, methyliminobispropylamine, H2N (CH2CH2O) 2 (CH2) 2NH2 ["Jeffamine EDR148" (diamine having ethylene glycol skeleton) manufactured by San Techno Chemical Co., Ltd.] , 1,5-diamino-2-methylpentane ("MPMD" manufactured by DuPont Japan), metaxylylenediamine (MXDA), polyamidoamine ("X2 manufactured by Sanwa Chemical Co., Ltd." 000 ”), isophoronediamine, 1,3-bisaminomethylcyclohexane (“ 1,3BAC ”manufactured by Mitsubishi Gas Chemical Co., Inc.), 1-cyclohexylamino-3-aminopropane, 3-aminomethyl-3,3,5-trimethyl. Examples thereof include cyclohexylamine and dimethyleneamine having a norbornane skeleton (“NBDA” manufactured by Mitsui Chemicals, Inc.).
Among them, 1,3-bisaminomethylcyclohexane, dimethyleneamine having a norbornane skeleton, metaxylylenediamine, H2N (CH2CH2O) 2 (CH2) 2NH2 (diamine having an ethyleneglycol skeleton), because of its particularly high curing rate, Examples include propylene skeleton diamine, propylene skeleton triamine, and polyamidoamine (trade name: X2000).
Ketimines, which are reaction products of these polyamines and ketones, are also included in the amine compounds, and acetophenone or propiophenone and 1,3-bisaminomethylcyclohexane are included from the viewpoints of stability, adjustment of reactivity, and recoatability. Those obtained from acetophenone or propiophenone and dimethylene amine (NBDA) having a norbornane skeleton; those obtained from acetophenone or propiophenone and metaxylylenediamine; acetophenone or propiophenone; Those obtained from, for example, diamine having ethylene glycol skeleton or propylene skeleton, such as Jeffamine EDR148, Jeffamine D230, and Jeffamine D400, or triamine having propylene skeleton, such as Jeffamine T403, It is below.

As the carbodiimide compound, a compound having two or more carbodiimide groups (-N = C = N-) in the molecule is preferably used, and a known polycarbodiimide can be used.
As the carbodiimide compound, a high molecular weight polycarbodiimide produced by decarboxylation condensation reaction of diisocyanate in the presence of a carbodiimidization catalyst can also be used.
Examples of such a compound include those obtained by subjecting the following diisocyanates to a decarboxylation condensation reaction. Examples of the diisocyanate include 4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-di'phenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'- Diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4, One of 4'-dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate or a mixture thereof can be used. As the carbodiimidization catalyst, 1-phenyl-2-phospholen-1-oxide, 3-methyl-2-phospholen-1-oxide, 1-ethyl-3-methyl-2-phospholen-1-oxide, 1-ethyl- 2-Phosphorene-1-oxide, or a phospholene oxide such as a 3-phospholene isomer thereof can be used.

  As the oxazoline compound, a compound having two or more oxazoline groups in the molecule is preferably used. Specifically, 2'-methylenebis (2-oxazoline), 2,2'-ethylenebis (2-oxazoline), 2 , 2'-ethylenebis (4-methyl-2-oxazoline), 2,2'-propylenebis (2-oxazoline), 2,2'-tetramethylenebis (2-oxazoline), 2,2'-hexamethylene Bis (2-oxazoline), 2,2'-octamethylenebis (2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (4,4 ') -Dimethyl-2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline), 2,2'-p-phenylenebis (4-phenyl-) -Oxazoline), 2,2'-m-phenylenebis (2-oxazoline), 2,2'-m-phenylenebis (4-methyl-2-oxazoline), 2,2'-m-phenylenebis (4, 4'-dimethyl-2-oxazoline), 2,2'-m-phenylenebis (4-phenylenebis-2-oxazoline), 2,2'-o-phenylenebis (2-oxazoline), 2,2'- o-phenylene bis (4-methyl-2-oxazoline), 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'-bis (4 -Ethyl-2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline) and the like. Alternatively, it may be a copolymer of a vinyl compound such as 2-isopropenyl-2-oxazoline or 2-isopropenyl-4,4-dimethyl-2-oxazoline and another monomer copolymerizable therewith.

  The melamine compound is a compound having a triazine ring in the molecule, and examples thereof include melamine, benzoguanamine, cyclohexanecarboguanamine, methylguanamine, vinylguanamine, hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine and the like. Further, these low condensation products, alkyl etherified formaldehyde resins and aminoplast resins may be used.

  The amount of the cross-linking agent (C) to be used may be determined in consideration of the adhesive physical properties and the like, and is not particularly limited. It needs to be optimized. The amount of the cross-linking agent (C) used is preferably 0.0001 to 10 parts by weight based on 100 parts by weight of the total amount of the acrylic copolymer (A-1) and the acrylic copolymer (A-2). , And more preferably 0.001 to 1 part by weight. If the amount of the cross-linking agent (C) used is less than 0.0001 parts by weight, the cohesive force is low and there is a risk of adhesive residue during peeling. On the other hand, when the amount of the cross-linking agent (C) used exceeds 10 parts by weight, the elasticity of the pressure-sensitive adhesive layer becomes high, the tack is lowered, and the adhesive force is lowered, so that it is floated when it is stuck on the uneven surface of the vehicle. Or it may come off. Will occur. The addition method of adding the cross-linking agent (C) constituting the pressure-sensitive adhesive is not particularly limited.

<Urethane resin composition>
The urethane resin composition is a resin adhesive containing a urethane resin (B) described below and the above-mentioned crosslinking agent (C) as main components. As a form, a method of applying a resin composition to a release film, drying, and then sandwiching the release film to create an adhesive sheet, or directly printing in the form of a wiring sheet to seal the conductive coupling part is also possible. I can. When forming a sheet, a double-sided tape can be prepared by laminating an adhesive on both sides of a plastic substrate.

<Urethane resin>
The method for synthesizing the urethane resin (B) is not particularly limited. For example, the polyol compound (a) is reacted with the diisocyanate (b), or the polyol compound (a), the diisocyanate (b) and a diol compound having a carboxyl group. (C) is reacted to obtain a urethane prepolymer (d) having an isocyanate group, the urethane prepolymer (d) is further reacted with a polyamino compound (e), or in the above three cases, it is necessary. Examples thereof include those obtained by reacting a reaction terminator.

  As the polyol compound (a), various polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene glycols, or a mixture thereof, which are generally known as a polyol component constituting a polyurethane resin, can be used.

Examples of the polyether polyols include polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran and the like.
Examples of polyester polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1, Saturated and unsaturated low molecular weight diols such as 5-pentanediol, hexanediol, octanediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol and dimer diol, and n-butylglycidyl ether, 2 -Alkyl glycidyl ethers of ethylhexyl glycidyl ethers, monocarboxylic glycidyl esters such as versatic acid glycidyl esters, and adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid Fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, dicarboxylic acids such as sebacic acid, or their anhydrides, polyester polyols obtained by dehydration condensation, Examples thereof include polyester polyols obtained by ring-opening polymerization of cyclic ester compounds.

As the polycarbonate polyols, 1) a reaction product of a diol or bisphenol and a carbonic acid ester, and 2) a reaction product of diol or bisphenol with phosgene in the presence of an alkali can be used. Examples of the carbonic acid ester include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate and propylene carbonate. Further, as the diol, ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 3,3 '-Dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9 -Nonanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl, 2,2 , 8 Examples thereof include 10-tetraoxospiro [5.5] undecane, etc. Examples of bisphenols include bisphenol A, bisphenol F, and bisphenols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to bisphenols. .

The number average molecular weight (Mn) of the above-mentioned polyol compound is appropriately determined in consideration of the solubility of the polyurethane resin at the time of producing the conductive composition, the durability of the conductive film to be formed, the adhesive strength to the substrate, and the like. However, the range of 580 to 8000 is usually preferable, and the range of 1000 to 5000 is more preferable. If the Mn is less than 580, the number of urethane bonds in the polyurethane resin will be too large, and the flexibility of the polymer skeleton will decrease, tending to deteriorate the adhesion to the substrate. If the Mn exceeds 8000, the crosslinking point will increase. There is a tendency that the intermolecular weight becomes large and sufficient coating film strength cannot be obtained after hot pressing.
The above polyol compounds may be used alone or in combination of two or more kinds. Further, a part of the above-mentioned polyol compounds may be replaced with low-molecular diols, for example, various low-molecular diols used for the production of the above-mentioned polyol compounds, within a range in which the performance of the polyurethane resin is not lost.

As the diisocyanate compound (b), aromatic diisocyanate, aliphatic diisocyanate, alicyclic isocyanate, or a mixture thereof can be used, but isophorone diisocyanate is particularly preferable. As aromatic diisocyanates, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-benzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1 , 3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate and the like.

Examples of the aliphatic diisocyanate include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and lysine diisocyanate.
Examples of the alicyclic diisocyanate include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, norbornane diisocyanatomethyl, bis (4-isocyanate cyclohexyl) methane, 1,3-bis (isocyanatomethyl) cyclohexane, and methylcyclohexane diisocyanate. To be

Examples of the diol compound (c) having a carboxyl group include dimethylolalkanoic acid such as dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylolpentanoic acid, dihydroxysuccinic acid, and dihydroxybenzoic acid. Particularly, dimethylolpropionic acid and dimethylolbutanoic acid are preferable from the viewpoint of reactivity and solubility.
Conditions for obtaining the urethane prepolymer (d) having an isocyanate group by reacting the polyol compound (a), the diisocyanate (b) and the diol compound (c) having a carboxyl group are as follows: Although not particularly limited, the isocyanate group / hydroxyl group equivalent ratio is preferably in the range of 1.05 / 1 to 3/1. More preferably, it is 1.2 / 1 to 2/1. The reaction is usually carried out at room temperature to 150 ° C, and preferably at 60 to 120 ° C from the viewpoint of production time and control of side reactions.

The polyamino compound (e) functions as a chain extender, and includes ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, norbornanediamine, and 2 It is also possible to use amines having a hydroxyl group such as-(2-aminoethylamino) ethanol, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxypropylethylenediamine. it can. Among them, isophoronediamine is preferably used.

When the urethane prepolymer (d) having an isocyanate group is reacted with the polyamino compound (e) to synthesize a polyurethane resin, a reaction terminator can be used together in order to adjust the molecular weight of the obtained polyurethane resin. As the reaction terminator, dialkylamines such as di-n-butylamine, dialkanolamines such as diethanolamine, and alcohols such as ethanol and isopropyl alcohol can be used.

The conditions for reacting the urethane prepolymer (d) having an isocyanate group with the polyamino compound (e) and, if necessary, the reaction terminator are not particularly limited, but free isocyanates at both terminals of the urethane prepolymer are used. When the groups are 1 equivalent, the total equivalent of the amino groups in the polyamino compound (e) and the reaction terminator is preferably in the range of 0.5 to 1.3. More preferably, it is within the range of 0.8 to 0.995.
The weight average molecular weight of the polyurethane resin is preferably in the range of 5,000 to 200,000. When the molecular weight is less than 5,000, a conductive composition containing the resin as a binder cannot have a good resin viscosity, resulting in poor coatability. When it exceeds 200,000, the viscosity of the resin solution itself is high and the handling property is deteriorated, which is not preferable.

At the time of synthesizing the polyurethane resin, one or two kinds selected from ester solvents, ketone solvents, glycol ether solvents, aliphatic solvents, aromatic solvents, alcohol solvents, carbonate solvents, water, etc. The above can be used in combination.
Examples of the ester solvent include ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, ethyl lactate and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone benzene, diisobutyl ketone, diacetone alcohol, isophorone, cyclohexanone and the like.
Examples of glycol ether solvents include ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, and acetic acid esters of these monoethers, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene. Examples thereof include glycol monomethyl ether, propylene glycol monoethyl ether, and acetic acid esters of these monoethers.
Examples of the aliphatic solvent include n-heptane, n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane and the like.
Examples of the aromatic solvent include toluene and xylene.
Examples of the alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, cyclohexanol and the like.
Examples of the carbonate-based solvent include dimethyl carbonate, ethylmethyl carbonate, di-n-butyl carbonate and the like.

<Polyamide resin composition>
As the encapsulating material, a polyamide resin composition containing the polyamide resin (D) as a main component and the cross-linking agent (C) is preferable from the viewpoint of adhesion to the substrate. The sealing property is a good result because the resin component in the hot press easily flows.

<Polyamide resin>
The polyamide resin (D) used in the present invention is basically a high-concentration amide bond obtained by various reactions such as polycondensation of dibasic acid and diamine, polycondensation of aminocarboxylic acid, or ring-opening polymerization of lactam. A generic term for molecules, including various modified polyamides, products produced with partially hydrogenated reactants, products obtained by partially copolymerizing other monomers, or other substances such as various additives. It is a broad concept including mixed things.

The polyamide resin (D) used in the present invention is not particularly limited as long as the above-mentioned conditions are satisfied, but a dimer acid-modified polyamide obtained by condensation polymerization of a dibasic acid containing dimer acid as a main component and polyamines. Resins are preferred. As the dimer acid for producing the dimer acid-modified polyamide resin, tall oil fatty acid, dimer acid obtained by polymerizing natural monobasic unsaturated fatty acid contained in soybean oil fatty acid, etc. is widely used industrially. In addition, various dicarboxylic acids such as saturated aliphatic, unsaturated aliphatic, alicyclic, and aromatic may be used.
Examples of commercial products of the dimer acid include Haridimer 200, 300 (manufactured by Harima Chemicals), Versadim 228, 216, Empor 1018, 1019, 1061, 1062 (manufactured by Cognis) and the like. Further, hydrogenated dimer acid can also be used, and commercially available products of hydrogenated dimer acid include Pripol 1009 (manufactured by Croda Japan Co., Ltd.) and Enpol 1008 (manufactured by Cognis Corporation).
In addition to the above dimer acid, various dicarboxylic acids can be used as the dibasic acid in order to obtain a polyamide resin having appropriate flexibility. Specific examples of the dicarboxylic acid include oxalic acid, malonic acid, (anhydrous) succinic acid, (anhydrous) maleic acid, glutaric acid, adipic acid, vimelic acid, suberic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid. Acid, phthalic acid, naphthalenedicarboxylic acid, 1,3- or 1,4-cyclohexanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid and the like are used.

Further, those having a phenolic hydroxyl group can be used as the dibasic acid. By using a dibasic acid having a phenolic hydroxyl group, the phenolic hydroxyl group can be introduced into the side chain of the polyamide resin and can be used for the reaction with the crosslinking agent (C).
As the dibasic acid having a phenolic hydroxyl group,
2-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, hydroxyisophthalic acid such as 5-hydroxyisophthalic acid,
2,5-dihydroxyisophthalic acid, 2,4-dihydroxyisophthalic acid, dihydroxyisophthalic acid such as 4,6-dihydroxyisophthalic acid,
2-hydroxyterephthalic acid, 2,3-dihydroxyterephthalic acid, dihydroxyterephthalic acid such as 2,6-dihydroxyterephthalic acid,
Hydroxyphthalic acid such as 4-hydroxyphthalic acid and 3-hydroxyphthalic acid,
Examples thereof include dihydroxyphthalic acid such as 3,4-dihydroxyphthalic acid, 3,5-dihydroxyphthalic acid, 4,5-dihydroxyphthalic acid and 3,6-dihydroxyphthalic acid.
Further, these acid anhydrides and ester derivatives such as polybasic acid methyl ester are also included.
Of these, 5-hydroxyisophthalic acid is preferable from the viewpoints of copolymerizability, availability, and the like.

Further, in order to obtain a polyamide resin having an appropriate fluidity when heated, various monocarboxylic acids are used if necessary. Specific examples of the monocarboxylic acid include propionic acid, acetic acid, caprylic acid (octanoic acid), stearic acid, and oleic acid.
The polyamines as a reaction product when the above-mentioned dimer acid-modified polyamide resin is produced are, for example, various diamines such as aliphatic, alicyclic and aromatic diamines, triamines and polyamines.
Specific examples of the diamine include ethylenediamine, propanediamine, butanediamine, triethylenediamine, tetraethylenediamine, hexamethylenediamine, p- or m-xylenediamine, 4,4′-methylenebis (cyclohexylamine), 2,2-bis. -(4-cyclohexylamine), polyglycol diamine, isophorone diamine, 1,2-, 1,3- or 1,4-cyclohexanediamine, 1,4-bis- (2'-aminoethyl) benzene, N-ethyl Aminopiperazine, piperazine and the like can be mentioned.
Examples of triamine include diethylenetriamine, and examples of polyamine include triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and the like. Furthermore, the dimer diamine obtained by converting the dimerized aliphatic nitrile group and hydrogen-reducing it can also be used.

In addition, examples of the polyamine compound include compounds in which a carboxyl group of a polybasic acid compound having a cyclic or acyclic hydrocarbon group having 20 to 48 carbon atoms is converted into an amino group, and examples of commercially available products include, for example, Croda. Examples include "Puriamine 1071", "Puriamine 1073", "Puriamine 1074" and "Puriamine 1075" manufactured by Japan Co., Ltd., and "Versamine 551" manufactured by Cognis Japan K.K.
An alkanolamine may be used in combination with the diamine. Examples of the alkanolamine include ethanolamine, propanolamine, diethanolamine, butanolamine, 2-amino-2-methyl-1-propanol, 2- (2-aminoethoxy) ethanol and the like.
Further, a polyether diamine having oxygen as a skeleton can be used. This polyether is represented by the general formula H ₂ N—R ₁ — (RO) _n —R ₂ —NH ₂ (wherein n is 2 to 100 and R ₁ and R ₂ have 1 to 14 carbon atoms). An alkyl group or an alicyclic hydrocarbon group, R is an alkyl group or an alicyclic hydrocarbon group having 1 to 10 carbon atoms, and the alkyl group may be linear or branched. It may be. Examples of the ether diamine include polyoxypropylene diamine and the like, and commercially available products include Jeffamines (manufactured by San Techno Chemical Co.). In addition, bis- (3-aminopropyl) -polytetrahydrofuran can also be mentioned.
The polyamines and dimer acid or various dicarboxylic acids are heat-condensed by a conventional method, and various polyamide resins including dimer acid-modified polyamide resin are produced by an amidation step accompanied by dehydration. Generally, the reaction temperature is about 100 to 300 ° C., and the reaction time is about 1 to 8 hours.

<Sheet-like substrate (1)>
INDUSTRIAL APPLICABILITY The wiring sheet of the present invention is suitable for wearable sensing wiring for acquiring a biomedical signal of the body for which a flexible wiring base material is required. It can also be used for applications such as measuring an electrocardiogram at a level of several days to one month. In addition, it is necessary to design various components at low cost for applications that can be easily installed and are discarded after several measurements.

The base material is selected from resin sheets. For example, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polycarbonate resins, polyarylate resins, acrylic resins, polyphenylene sulfide resins, polystyrene resins, vinyl resins, vinyl chloride resins Examples of the resin sheet include a resin such as a polyimide resin, an epoxy resin, a polyolefin resin such as polyethylene, polypropylene, and poolinorbornene. Further, since a high temperature treatment process in which the base material is deformed by heat may be required, it is necessary to fill the base material with high heat resistance such as polyimide (PI) sheet, polynaphthalene sheet, propylene sheet, silicone resin sheet or filler filling. Although a substrate having improved heat resistance can be used, PET, PEN, and PVC are preferable for inexpensive use. In that case, low temperature bonding at 130 ° C. or lower is required.

<Conductive wiring (2)>
The first conductive wiring (2) used in the present invention is prepared by printing a conductive circuit on the sheet-shaped base material (1) with a conductive ink of metal or carbon on the sheet-shaped base material. To be done.

(Conductive ink)
The conductive material of the conductive ink is not particularly limited as long as it has conductivity, but graphite, carbon black, conductive carbon fibers (carbon nanotubes, carbon nanofibers, carbon fibers), carbon such as fullerene In addition to the materials, metal powders such as gold, silver, copper, aluminum, nickel and tin can be used alone or in combination of two or more.

Binder resins for dispersing the conductivity imparting agent in the conductive ink include polyurethane-based, polyamide-based, acrylonitrile-based, acrylic-based, butadiene-based, polyvinyl butyral-based, polyolefin-based, polyester-based, polystyrene-based, EVA-based, fluorine-based One or more selected from the group consisting of (polyvinylidene fluoride based) and silicon based resin can be included. However, it is not limited to these resins. The binder resins may be used alone or in combination of two or more. In particular, the binder resin preferably contains at least one resin selected from urethane resins, polyester resins, polyamide resins, acrylic resins, fluorine resins, epoxy resins, and styrene elastomers.
The binder resin can also be a curable resin that undergoes a curing (crosslinking) reaction after the binder resin is applied to the substrate.
In other words, the binder resin can be selected (self-curing) or combined with a crosslinking agent to be cured (crosslinked) after printing or coating the conductive composition on the substrate. .

(Production method of conductive ink)
The conductive ink may be produced by premixing the conductive material, the binder resin, and other components such as an inorganic filler, a fluidity modifier, a solvent, and a defoaming agent, if necessary, and then performing a dispersion treatment. I can. The dispersion method is not particularly limited, but specifically, the constituent components are uniformly mixed in a three-roll mill, a sand mill, etc., and the powder components such as the conductive material and the inorganic filling material are pulverized to a certain particle size or less. In addition to imparting printability in the printing step and drying property during drying, the performance as a conductive wiring after printing is exhibited.

(How to print conductive ink)
The method for applying the conductive composition onto the sheet-shaped substrate is not particularly limited and a known method can be used.

Specific examples thereof include die coating method, dip coating method, roll coating method, doctor coating method, knife coating method, spray coating method, gravure coating method, screen printing method or electrostatic coating method, and drying. As the method, standing drying, blower dryer, warm air dryer, infrared heater, far infrared heater and the like can be used, but the method is not particularly limited thereto.
Further, a rolling treatment using a lithographic press or a calendar roll may be performed after coating.

<Film protective layer (3)>
The wiring sheet in which the first conductive wiring (2) is printed on the above-mentioned sheet-shaped substrate is covered with an insulating film, and the conductive wiring as a protective layer of the first conductive wiring is directly exposed to the outside air. Play a role in preventing The resin sheet is selected as the base material of the film protective layer. Examples of the resin sheet include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polycarbonate resins, polyarylate resins, acrylic resins, polyphenylene sulfide resins, polystyrene resins, vinyl resins. A resin sheet formed of a resin such as a vinyl chloride resin, a polyimide resin, an epoxy resin, a polyolefin resin such as polyethylene, polypropylene, or porinorbornene. Further, since a high temperature treatment process in which the base material is deformed by heat may be required, it is necessary to fill the base material with high heat resistance such as polyimide (PI) sheet, polynaphthalene sheet, propylene sheet, silicone resin sheet or filler filling. Although a substrate having improved heat resistance can be used, PET, PEN, and PVC are preferable for inexpensive use. In that case, low temperature bonding at 130 ° C. or lower is required.

  An adhesive layer or an adhesive layer is formed on one surface of the film protective layer, and the film protective layer is laminated on the sheet-shaped substrate (1) on which the first conductive wiring (2) is formed. As the adhesive, an acrylic or urethane adhesive can be used as appropriate. As the adhesive, an olefin-based, rubber-based, polyamide-based hot-melt adhesive for extrusion lamination, polyester-based, acrylic-based, or epoxy-based adhesive for dry lamination can be appropriately used.

<Conductive wiring (4)>
As the second conductive wiring (4) used in the present invention, in addition to the case where the conductive wiring sheet (1) is used in combination, a sheet-shaped base material such as PET or PI is metal-etched with copper or aluminum. In addition to metal wiring sheets that are circuit-formed by the method and metal wiring sheets that are adhesively bonded to a sheet-shaped substrate with a metal foil that is adhesively coated on one side, wiring cords that cover metal wires such as copper and aluminum with insulating resin are also used. It

<Insulation protection layer (5)>
The second conductive wiring may be sheet-shaped or cord-shaped. In the case of a sheet, the same film protective layer as the above-mentioned first conductive wiring (2) by printing is used. In the case of the metal wiring sheet to which the above-mentioned metal etching or metal foil is pasted, in addition to laminating a film which is adhesive or bonded on one side of the PET or PI film, and applying a liquid insulating material by printing. There is also. In the case of the wiring cord, it is covered with polyvinyl chloride or the like.

<Conductive adhesive (6)>
According to the present invention, the first conductive wiring (2) and the second conductive wiring (4) are joined with a conductive adhesive (6). The conductive adhesive is prepared by dispersing a metal or carbon conductive component in a resin binder.

The conductive adhesive (6) is made of a metal or carbon conductive ink. The conductive material is not particularly limited as long as it is a material having conductivity, but graphite, carbon black, conductive carbon fibers (carbon nanotubes, carbon nanofibers, carbon fibers), fullerene and other carbon materials can be used. In addition, metal powders such as gold, silver, copper, aluminum, nickel and tin can be used alone or in combination of two or more kinds.

Binder resins for dispersing the conductivity-imparting agent are epoxy-based, polyurethane-based, polyamide-based, acrylonitrile-based, acrylic-based, butadiene-based, polyvinyl butyral-based, polyester-based, polystyrene-based, EVA-based, fluorine-based (polyvinylidene fluoride). And the like) and silicon-based resins and the like. However, it is not limited to these resins. The binder resins may be used alone or in combination of two or more. In particular, the binder resin preferably contains at least one resin selected from urethane resins, polyester resins, polyamide resins, acrylic resins, fluorine resins, epoxy resins, and styrene elastomers.
The binder resin can also be a curable resin that undergoes a curing (crosslinking) reaction after the binder resin is applied to the substrate. That is, the binder resin can be selected (self-curable) or combined with a cross-linking agent so that the conductive composition is printed or coated on the substrate and then cured (cross-linked).

Since the conductive adhesive is used for conductive bonding between conductive wirings, it is desirable that it does not contain a solvent.
When a solvent is contained, the solvent sandwiched between the conductive wirings cannot be volatilized and remains, so that the adhesive performance and the conductive function may not be exhibited. The conductive adhesive cross-links the binder resin component at room temperature or by heating to withstand adhesiveness and high temperature and high humidity environment, and achieves bonding exhibiting stable conductivity.

The conductive adhesive (6) may be a sheet-shaped conductive adhesive sheet. The sheet-shaped conductive adhesive is used by dispersing the above-mentioned conductive material in a thermoplastic resin and then sheeting it.

<Joining encapsulant>
In the conductive sheet 1 produced by laminating the first conductive wiring (2) printed on the sheet-shaped substrate (1) and the film protective layer (3) for protecting the first conductive wiring, The conductive adhesive (6) is placed in the opening for exposing the conductive wiring of FIG. Next, the encapsulating material (6) is arranged in the peripheral portion of the first opening, and the wiring portion of the second conductive wiring (2) is pressure-bonded, and if necessary, thermocompression-bonded, so that conduction is achieved. At the same time that the sheet 1 and the second conductive wiring are conductively coupled, the peripheral portion is coupled by the sealing material.

The method for joining the encapsulant and the base material is not particularly limited, but thermocompression bonding is not required when the encapsulant has adhesiveness and exhibits an adhesive strength of 10 N only by pressure bonding at room temperature. If the encapsulant does not have tackiness or is slightly tacky and has an adhesive strength of less than 10 N by pressure bonding, it is sealed on the adherend with a heating temperature of 130 ° C. or less using a heat iron or an IH heating device. It can be manufactured by melting the stopping material composition and joining the sealing material and the adherend.

  The present invention can also be used for a film substrate having no heat resistance such as PET (polyethylene terephthalate) and PVC (polyvinyl chloride). The heat resistant temperature of these films is 130 ° C. or lower, and at temperatures higher than that, the films shrink due to heat. Therefore, it is preferable that the bonding temperature of the sealing material is 130 ° C. or lower, preferably 100 ° C. or lower.

<Adhesive strength>
Although the adhesive strength value of the hot melt adhesive composition varies depending on the adherend, the preferable range is 2N or more and less than 100N, and more preferably 10N or more. The detailed measuring method of the adhesive force will be specifically described in Examples.

Hereinafter, the present invention will be described specifically and in detail with reference to Examples, but these Examples are merely one aspect of the present invention, and the present invention is not limited to these Examples. In the table, "part" means "part by weight", and "%" means "% by weight".

[Adjustment of hot melt adhesive and encapsulant sheet]
[Production Example 1]
In a stainless beaker equipped with a stirrer, SIS 1:40 parts as a thermoplastic resin, tackifier 1:50 parts as a tackifier, and softener 1:10 parts as a softener are charged and heated at a temperature of 150 ° C. Melted. Then, stirring was performed to obtain a uniform molten solution. The hot-melt adhesive composition 1 uniformly dispersed is sandwiched between release films and heat-pressed at 100 ° C. 100 kgf / cm ² for 30 seconds by a tester industry tabletop test press machine to form a sheet having a film thickness of 200 to 300 μm. A sealing material sheet 1 was obtained.
[Production Examples 2 to 18]
The hot melt adhesives 2 to 18 and the encapsulant sheet were prepared in the same manner as the preparation of the hot melt adhesive 1 and the encapsulant sheet 1 except that the raw materials and the composition ratio were changed as described in Table 1. 2-18 were created.

The softening point was measured according to JIS 6863 "Test method for softening point of hot melt adhesive".
That is, the sample was melted and filled in a ring having an inner diameter of 15.9 mm and a height of 6.4 mm and solidified at room temperature, and then a sphere having a diameter of 9.5 mm and a mass of 3.5 g was placed on the sample and placed in a silicone oil bath. The temperature at which the sphere descended by heating was defined as the softening point. Table 1 shows the softening point of each hot melt resin composition.

The abbreviations of the thermoplastic resin, tackifier, softening agent and other components shown in Table 1 are shown below.
<Thermoplastic elastomer resin>
・ SIS1: Clayton Co., Ltd. Product name: D1117
・ SBS1: Clayton Co., Ltd. Product name: D1155
・ SEBS1: Clayton Co., Ltd. Product name: G1726
・ SEBS2: Clayton Co., Ltd. Product name: G1652
・ SEBS3: Clayton Co., Ltd. Product name: G1657
・ SEBS4: Clayton Co., Ltd. Product name: G1643
・ SEBS5: Clayton Co., Ltd. Product name: G1650
・ SEPS1: Kuraray Co., Ltd. Product name: SEPS2063

<Tackifying resin>
・ Tackifier 1: Arakawa Chemical Industry Co., Ltd. Product name: Alcon P-100
-Tackifier 2: Arakawa Chemical Co., Ltd. Product name: Alcon P-140

<Softener>
・ Softening agent 1: Idemitsu Kosan Co., Ltd. Product name: Diana Process Oil N90
・ Softening agent 2: Idemitsu Kosan Co., Ltd. Product name: Diana Process Oil PW90
・ Softening agent 3: JX Energy Co., Ltd. Product name: Nisseki Polybutene HV-1900

[Adjustment of thermosetting adhesive]
[Production Example 19]
<Production of Polyurethane Resin Composition 1>
A polyester polyol (manufactured by Kuraray Co., Ltd.) obtained from terephthalic acid, adipic acid, and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube. "Kuraray polyol P-2011", Mn = 2011) 455.5 parts, dimethylolbutanoic acid 16.5 parts, isophorone diisocyanate 105.2 parts, and toluene 140 parts were charged and reacted at 90 ° C for 3 hours under a nitrogen atmosphere. To the mixture, 360 parts of toluene was added to obtain a urethane prepolymer solution having an isocyanate group. Next, a mixture of 19.9 parts of isophoronediamine, 0.63 part of di-n-butylamine, 294.5 parts of 2-propanol, and 335.5 parts of toluene was added to the resulting urethane prepolymer solution having an isocyanate group. 969.5 parts were added, and the mixture was reacted at 50 ° C. for 3 hours and then at 70 ° C. for 2 hours, diluted with 126 parts of toluene and 54 parts of 2-propanol, Mw = 61,000, acid value = 10 mgKOH / g, urethane prepolymer. A solution of polyurethane resin A in which the total equivalent weight of the polyamino compound and the amino groups in the reaction terminator was 0.98 with respect to the free isocyanate groups at both ends of the polymer was obtained.

The above-mentioned urethane resin A and aziridine PZ33 (manufactured by Nippon Shokubai Co., Ltd.) were mixed in a ratio of 100: 3, and a PET film separator 50 μm (SP-PET01-50BU: manufactured by Mitsui Chemicals Tohcello) coated with silicone was coated at a coating amount of 30 g / It was coated to m ² (dry), dried at 80 ° C. for 5 minutes, and allowed to stand for 24 hours to obtain a urethane resin sheet 1.

[Production Example 20]
<Production of Polyamide Resin Composition 1>
Henkel Hakusui polyamide resin "Macromelt 6202" was dissolved in toluene and isopropyl alcohol (mixing ratio 1: 1) to obtain a solution of polyamide resin A. To 100 parts of the same resin, 1 part of N, N, N ′, N′-tetraglycidyl-m-xylylenediamine as an epoxy crosslinking agent was added and stirred uniformly to obtain a polyamide composition. Peeling Silicone-treated PET film separator 50 μm (SP-PET01-50BU: manufactured by Mitsui Chemicals Tohcello) was coated at a coating amount of 30 g / m ² (dry), dried at 90 ° C. for 1 minute, and then polyamide resin. Sheet 1 was obtained.

[Production Example 21]
<Production of acrylic resin composition 1>
70 parts of n-butyl acrylate, 20 parts of methyl acrylate, and 2-ethyl in a reaction container (hereinafter simply referred to as "reaction container") equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction pipe. After charging 4 parts of hexyl acrylate, 6 parts of acrylic acid, 72 parts of ethyl acetate, and 0.13 parts of 2,2′-azobis (2-methylbutyronitrile), the air in the reaction vessel was replaced with nitrogen gas. The reaction solution was reacted at a reflux temperature for 8 hours in a nitrogen atmosphere while stirring. After the reaction was completed, the reaction mixture was diluted with ethyl acetate to obtain a solution of an acrylic copolymer a1 having a nonvolatile concentration of about 30% and a weight average molecular weight of Mw 1.05 million.
100 parts of toluene was charged to the reaction vessel, 95 parts of n-butyl methacrylate and 5 parts of N, N-dimethylaminoethylmethacrylate were charged to the dropping device, and the air in the reaction vessel was replaced with nitrogen gas, followed by stirring. While dropping under a nitrogen atmosphere for 1 hour, the reaction solution was reacted at reflux temperature for 8 hours. After completion of the reaction, the reaction mixture was diluted with ethyl acetate to obtain a solution of acrylic copolymer a2 having a nonvolatile concentration of about 30% and a weight average molecular weight Mw of 50,000.
Add 75 parts by weight of the acrylic copolymer solution a1, 25 parts by weight of the acrylic copolymer solution a2, and add 0.021 parts of N, N, N ′, N′-tetraglycidyl-m-xylylenediamine as an epoxy crosslinking agent. The mixture was stirred uniformly to obtain a pressure sensitive adhesive a.
Peeling Silicone-treated PET film separator 50 μm (SP-PET01-50BU: manufactured by Mitsui Chemicals Tohcello) was coated at a coating amount of 30 g / m ² (dry), dried at 90 ° C. for 1 minute, and then acrylic resin. Sheet 1 was obtained.

Table 2 describes the resin sheets of Production Examples 19 to 21.

[Example 1 (Creation of wiring sheet 1)]
A conductive wire of 5 mm × 100 mm was printed with a conductive carbon ink on a sheet base material of a PET film (Luminar X10S manufactured by Toray Industries) of 125 μm thickness and 25 mm × 100 mm, and dried at 100 ° C. for 30 minutes. After opening 125 μm PET film (Luminar X10S made by Toray Co., Ltd.) processed with acrylic adhesive in a size of 5 mm × 5 mm at a location 5 mm from the end, the carbon conductive wiring of the PET film on which conductive wiring was printed was exposed so that the carbon conductive wiring was exposed. Alignment was performed, and a film protective layer was laminated on the opposite side of the sheet so that the carbon wiring was exposed for resistance measurement. The case where this wiring sheet was used as the first conductive wiring sheet was designated as sample sheet 1, and the case where it was used as the second conductive wiring sheet was designated as sample sheet 2.

On the carbon wiring exposed in the opening of the sample sheet 1, an epoxy-based two-component room temperature curable conductive adhesive made by Chemitronics was applied. The encapsulant sheet 1 of the SIS1 hot melt adhesive of Production Example 1 of Manufacturing Example 1 having a size of 5 mm × 5 mm of the adhesive portion was provided around the periphery, and the sample sheet 2 was placed so that the openings overlap. I put them on top of each other.
After lightly pressing the conductive adhesive portion, the peripheral sealing material portion was thermocompression-bonded with a hot iron at 100 ° C. and left at room temperature for 24 hours to prepare a wiring sheet 1. (Fig. 2)

[Examples 2 to 21 and Comparative Example 1 (Creating Wiring Sheets 2 to 21 and Comparative Wiring Sheet 1)]
Wiring sheets 2 to 21 and comparative wiring sheet 1 were prepared in the same manner as wiring sheet 1 described above except that encapsulating material sheet 1 was changed as described in Table 1 and Table 2.
For the comparative wiring sheet 1, the sample sheet 1 and the sample sheet 2 were joined together using only the above-mentioned epoxy-based two-liquid room temperature curing type adhesive without using a sealing material.

Wiring Sheet Adhesion Test The wiring sheets 1 to 21 and the comparative wiring sheet 1 prepared above were subjected to an adhesion test using a tensile tester ZTA-500N manufactured by IMADA.

Specifically, the opposite ends of the joined portions of the sample sheets 1 and 2 to which the wiring sheets were joined were sandwiched by clamps, and the maximum value of the load when peeled off at about 10 mm / sec was measured. (Figure 3)
◯: Adhesive force is 50 N or more Δ: Adhesive force is 10 N or more and less than 50 N ×: Adhesive force is less than 10 N

The results are shown in Table 3.

2. Wiring Sheet Flexibility Test The wiring sheets 1 to 21 and the comparative wiring sheet were subjected to flexural judgment using a multifunctional small tabletop endurance tester DLDM111LH manufactured by Yuasa System Equipment Co., Ltd.

Specifically, after measuring the resistance value between both end portions of the wiring sheet, the end portions of the first conductive wiring and the end portions of the second conductive wiring, the measurement sample is subjected to a Uasa System Equipment endurance tester. It was set in a bent state, and an expansion / contraction test was performed at intervals of 70 mm to 20 mm and 30 rpm, and after the test, the presence or absence of breakage of the joint was evaluated by the resistance value between the wirings. (Figure 4)
◎: Resistance value fluctuation of ± 10% or less after 1000 expansions / contractions ○: Resistance value fluctuation of ± 10% or less at 100 expansions / contractions less than 1000 times ×: Breakage or resistance value of ± 10% or more at expansions / contractions less than 100 times

The results are shown in Table 3.

[Example 22 (Creation of wiring sheet 22)]
As the first conductive wiring sheet, Sample Sheet 1 was prepared by the same method as the above-mentioned wiring sheet adhesion test.

The second conductive wiring sheet is a 125 μm PET film processed with an acrylic adhesive and having a width of 10 mm and a copper foil tape manufactured by Teraoka Seisakusho attached to a sheet substrate of 125 mm thick 25 mm × 100 mm PET film (Toray Luminar X10S). After opening 5 mm x 5 mm at a location 5 mm from the end, the copper conductive wiring of the sample sheet 1 is exposed, and the end of the opposite surface is exposed so that the copper wiring is exposed 10 mm. The sheets were combined and laminated as a film protective layer to obtain Sample Sheet 3 as a second conductive wiring sheet. On the carbon wiring exposed from the opening of the sample sheet 1, an epoxy type two-component room temperature curing type silver adhesive manufactured by Chemitronics was applied. The encapsulant sheet 1 of the hot-melt adhesive composition containing SIS1 of Production Example 1 having a size of 5 mm × 5 mm of the adhesive portion and having SIS1 of Production Example 1 as a thermoplastic resin was placed around the encapsulant sheet 1. The sample sheets 3 were stacked and attached so that the openings overlap. After lightly pressing the conductive adhesive portion, the peripheral sealing material portion was thermocompression-bonded with a hot iron at 100 ° C. and left at room temperature for 24 hours to prepare a wiring sheet 22. (Fig. 5)

[Examples 23 to 42 and Comparative Example 2 (Creation of Wiring Sheets 23 to 42 and Comparative Wiring Sheet 2)]
Wiring sheets 23 to 42 and comparative wiring sheet 2 were prepared in the same manner as wiring sheet 22 described above except that encapsulating material sheet 1 was changed as shown in Table 4.
As for the comparative wiring sheet 2, the sample sheet 1 and the sample sheet 2 were joined only by the above-mentioned epoxy-based two-liquid room temperature curing type adhesive without using a sealing material.

3. Long-term reliability test Wiring sheets 22 to 42 were subjected to a long-term reliability test in the following procedure.

The resistance value between the conductive wirings at both ends of the sample sheet 1 and the sample sheet 3 was measured and set as the initial resistance, and the time was measured in an environment of 60 ° C. and 90% RH in a MODEL PL-1KPH environmental tester manufactured by ESPEC CORP for 1000 hours. After standing, the resistance values at both ends were measured again. After that, the sealing material at the joint was peeled off, and the appearance of the sealing film around the conductive joint and the appearance of the conductive material at the portion covered with the sealing film were visually observed.
◯: There is no change in the appearance of the encapsulant, no change in the appearance of the conductive material covered with the encapsulant, and the resistance value fluctuation is within ± 10% of the initial resistance
Δ: There is no change in the appearance of the encapsulant, but rust occurs in a part of the conductive material covered with the encapsulant, but the resistance value fluctuation is within ± 10% of the initial resistance.
×: Appearance change such as flow of the sealing material, change of appearance such as corrosion of the conductive material covered with the sealing material, or resistance value variation exceeds ± 10% of initial resistance

The results are shown in Table 4.

  From the results of Tables 3 and 4, the wiring sheets formed using the compositions prepared in Production Example 1 to Production Example 21 were different from Comparative Examples 1 and 2 in adhesiveness between wirings, bonding strength, and long-term reliability. Was found to be excellent. That is, it was found that the compositions prepared in Production Examples 1 to 21 were wiring sheets having better bondability as compared with Comparative Example 1.

Claims (8)

  A sheet-shaped substrate (1), a first conductive wiring (2) arranged on the sheet-shaped substrate, a film protective layer (3) for protecting the first conductive wiring, and a first A wiring sheet having a second conductive wiring (4) connected to a conductive wiring (2), wherein the first conductive wiring (2) and the second conductive wiring (4) are A wiring sheet, which is connected with a conductive adhesive (6) containing a metal or carbon, and the connected portion is sealed with a sealing material (7).   The wiring sheet according to claim 1, wherein the first conductive wiring (2) is a printed conductive wiring.   The wiring sheet according to claim 1 or 2, wherein the encapsulating material comprises a hot melt adhesive composition containing a styrene-based copolymer.   The styrene-based copolymer contains at least one selected from the group consisting of a styrene-isoprene copolymer, a hydrogenated styrene-isoprene copolymer, a styrene-butadiene copolymer, and a hydrogenated styrene-butadiene copolymer. The wiring sheet according to claim 3, wherein:   The wiring sheet according to claim 3 or 4, wherein the hot-melt adhesive composition further contains a tackifying resin. The mass ratio of the styrene copolymer and the tackifying resin in the hot melt adhesive composition is such that the mass of the styrene copolymer: the mass of the tackifying resin = 30: 70 to 100: 0. The wiring sheet according to any one of claims 3 to 5.   The wiring sheet according to claim 1 or 2, wherein the encapsulating material comprises a thermosetting adhesive composition containing at least one selected from the group consisting of acrylic resin, urethane resin, and polyamide resin.   8. The wiring sheet according to claim 1, wherein the sheet-shaped substrate (1) is PET (polyethylene terephthalate), PEN (polyethylene naphthalate) or PVC (polyvinyl chloride).