JP7124520B2 - wiring sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wiring sheet having conductive wirings arranged on the sheet.

Outdoor wiring is used in photovoltaic power generation, structures such as buildings, and the like. Therefore, there is a demand for wiring materials and wiring sheets that can be used in direct sunlight, in hot and humid environments, and that can be applied over a wide area.
Various techniques have been studied for conductive wiring materials.
(1) Distribution cables (including flat cables) covered with insulating material made of copper
(2) Rigid wiring board with copper wiring on glass epoxy board (3) Flexible printed circuit (FPC) with copper wiring on polyimide
(4) A conductive circuit in which a paste in which metal powders such as silver, copper, nickel, zinc, etc. are dispersed in resin is printed on a film, paper, etc., and heated and baked or sintered (5) Dispersed precious metal nanoparticles such as silver, copper, etc. A sintered circuit (6), a circuit with a conductive tape attached, and the like, but (3) to (6) are generally used as means for forming a circuit on a film.
Methods of sealing the conductive wiring material of (3), (4), and (5) include sealing with a polyimide coverlay and sealing by applying insulating ink such as polyimide or epoxy resin. Since these require a hot press process at 150°C or higher, heat baking, and a soldering process, they cannot be processed with general plastic films in many cases. can only be applied. Moreover, it is not possible to form a large-area circuit on a lithographic plate even in the hot press process.
In addition, even if the conductive layer is covered by laminating a sealing material obtained by applying adhesive processing to a polyimide coverlay or plastic film, the plastic film will permeate water vapor in a high-temperature, high-humidity environment. The conductive layer of the wire corrodes and loses conductivity, or migration of metals such as copper and silver causes short circuits. Therefore, studies have been made to protect the elements on the copper circuit and the substrate by forming a layer impermeable to water vapor on the circuit or the circuit substrate.
In Patent Document 1, a laminate obtained by laminating a thermoplastic resin, particularly a liquid crystal polyester, which exhibits optical anisotropy when melted through an adhesive layer and/or an adhesive layer on the circuit surface of a flexible printed wiring board. However, there is a problem with the adhesiveness of the liquid crystal film, and it is difficult to maintain the adhesiveness of the pressure-sensitive adhesive or adhesive against acid, alkali or water vapor.
Patent Document 2 proposes a printed wiring board characterized by providing a gas barrier layer on the semi-cured insulating resin layer in an insulating resin film for a printed wiring board having a semi-cured insulating resin layer. Although the gas barrier layer can prevent the intrusion of water vapor into the insulating resin layer to some extent, the gas barrier layer tends to crack over time and cannot be expected to be resistant to acids and alkalis, so it cannot be used for a long period of time.
Patent document 3 proposes a wiring substrate having excellent barrier performance against oxygen and water vapor that enter from the substrate side, but since the barrier layer is a metal layer, it cannot be expected to be resistant to acids and alkalis.

JP 2003-124580 JP 2006-135278 JP 2018-46076

In view of the above-mentioned circumstances, the inventors investigated a means of sealing a conductive wiring material provided on a film by laminating a weather-resistant film and a water vapor barrier material. The inventors found a means for sealing a conductive layer that can maintain conductivity in a hot and humid environment, or in an environment where acids and alkalis coexist, leading to the present invention.
An object of the present invention is to provide a wiring sheet that maintains the conductive layer of the conductive wiring sheet even in various environments and has excellent durability, and a manufacturing method thereof.

The inventors of the present invention have made intensive studies to solve the above problems, and as a result, the following form has good corrosion resistance, maintains the conductivity of the wiring sheet even in various outdoor environments, and has excellent durability. The present invention has been completed by finding that a wiring sheet having

That is, the present invention comprises a sheet-like substrate (1), a conductive wiring (2) arranged on the sheet-like substrate, a first water vapor barrier layer (3), and a weather resistant film layer (4). ) and relates to a wiring sheet characterized by having.

Alternatively, the wiring according to the present invention is characterized in that the weather-resistant film layer (4) contains at least one selected from the group consisting of polyethylene terephthalate resin, acrylic resin, fluororesin, polyamide resin, and vinyl chloride resin. Regarding the sheet.

The present invention also relates to the wiring sheet, wherein the water vapor barrier layer (3) contains a non-metallic inorganic oxide.

The wiring sheet of the present invention further comprises a pressure-sensitive adhesive layer or an adhesive layer, and the pressure-sensitive adhesive layer or adhesive layer is adjacent to the water vapor barrier layer (3). .

The present invention further relates to the wiring sheet, characterized by having a second water vapor barrier layer (5) on the surface of the sheet-like substrate (1) facing the conductive wiring (2).

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a wiring sheet having a conductive layer with good corrosion resistance and exhibiting stable conductivity.
Printing with a screen plate, metal mask, etc., or slit coating with a comma coater, die coater, etc., can be used to pattern a conductive composition into a wiring sheet, or to film-laminate a wiring sheet made from a conventional flexible printed circuit or conductive tape. By sealing with , it can withstand long-term use even in a highly corrosive environment, and can stably fulfill roles such as power supply and signal transmission.

FIG. 1 is a sectional view showing one embodiment of the wiring sheet of the present invention. FIG. 2 is a sectional view showing one embodiment of the wiring sheet of the present invention. FIG. 3 is a perspective top view showing one embodiment of the wiring sheet of the present invention.

The conductive wiring sheet of the present invention can be obtained by printing and coating a conductive composition on a sheet-like substrate (1) by various methods to form a conductive layer, or by laminating copper on a polyamide. A barrier laminate film in which conductive wiring is formed by patterning the copper of a clad laminate by etching, and the wiring sheet is further laminated with a weather-resistant film layer (2) and a water vapor barrier layer (3). A conductive wiring sheet can be obtained by sealing with.

<Conductive wiring sheet>
The conductive wiring sheet of the present invention comprises a sheet-like substrate (1), conductive wiring (2) arranged on the sheet-like substrate, a water vapor barrier layer (3), and a weather-resistant film layer ( 4).
In particular, it may have, in order, a sheet-like substrate (1), conductive wiring (2) arranged on the sheet-like substrate, a water vapor barrier layer (3), and a weather resistant film layer (4). preferable.

<Sheet-like base material (1)>
The shape of the sheet-like base material used for the conductive wiring sheet is not particularly limited, but an insulating resin film is preferable, and one suitable for various uses can be appropriately selected.

As the sheet-like base material, a material having particularly low conductivity and being able to withstand heat during drying for forming conductive wiring is selected. The sheet-like substrate (A) is preferably a plastic substrate having a thickness of 25 to 500 μm, and more preferably a sheet made of at least one selected from polyethylene terephthalate, polyimide, polyphenylene sulfide, polyvinyl chloride, and fluororesin.

As for the shape, a flat film is generally used, but substrates with roughened surfaces, primer-treated substrates, perforated substrates, and mesh-shaped substrates can also be used.

<Conductive wiring (2)>
The conductive wiring is formed by, for example, printing a conductive composition containing at least a binder resin and a conductivity-imparting agent with a screen plate, a metal mask, or the like, or slit coating with a comma coater, a die coater, etc. to form a conductive composition. obtained by patterning.
Alternatively, a conductive wiring can be formed by sticking a conductive tape on the sheet-like substrate (1) for simplification or repair. The conductive tape can be formed by applying a single-sided or double-sided tape of metal foil to the sheet-like substrate.
Alternatively, a flexible printed circuit in which a conductive layer is patterned by etching a copper foil can also be used.

<Conductivity imparting agent>
The conductive material is not particularly limited as long as it is a material having conductivity, but carbon materials such as graphite, carbon black, conductive carbon fiber (carbon nanotube, carbon nanofiber, carbon fiber), fullerene, etc. In addition, metal powders such as silver, copper, aluminum, nickel and tin can be used alone or in combination of two or more.
<Binder resin>
Binder resins for dispersing conductivity imparting agents include polyurethane, polyamide, acrylonitrile, acrylic, butadiene, polyvinyl butyral, polyolefin, polyester, polystyrene, EVA, fluorine (polyvinylidene fluoride system, etc.) and one or more selected from the group consisting of silicone-based resins and the like. However, it is not limited to these resins. Binder resin may be used individually by 1 type, and may be used in combination of 2 or more types. In particular, the binder resin preferably contains at least one resin selected from urethane resins, polyester resins, polyamide resins, acrylic resins, fluororesins, 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 is selected to be self-curing or combined with a curing agent described later, and the conductive composition is printed or coated on the substrate, and then cured (crosslinked). can be done.

After printing or coating the conductive composition on the base material, the resin portion softens when hot-pressed, and the planar pattern shape of the conductive film at the time of printing and coating is substantially maintained. Flowing in the thickness direction reduces the voids and increases the contact between the conductivity-imparting agents (C), so a decrease in the volume resistivity of the resulting conductive film can be expected. Therefore, the binder resin is preferably one that moderately softens and flows during hot pressing.

Both metallic conductive materials and non-metallic conductive materials such as carbon can be used for the conductive wiring. Since the conductivity does not decrease, it is possible to provide a conductive wiring that can withstand long-term use.

As the carbon material, for example, artificial graphite, natural graphite, or the like can be used. Artificial graphite is made by artificially orienting irregularly arranged fine graphite crystals by heat treatment of amorphous carbon, and is generally manufactured using petroleum coke or coal-based pitch coke as the main raw material. be. As the natural graphite, scale-like graphite, block-like graphite, soil-like graphite, and the like can be used. In addition, expanded graphite obtained by chemically treating flake graphite (also referred to as expandable graphite), expanded graphite obtained by subjecting the expanded graphite to heat treatment to expand it, and then pulverizing or pressing the expanded graphite may also be used. I can. Among these graphites, when used for the conductive layer of the wiring sheet, expanded graphite and flake graphite are preferable from the viewpoint of conductivity.

<Solvent>
Solvents include water, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether and diethylene glycol methyl ether, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether. and other 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, depending on the composition of the conductive composition. Any suitable one can be used. Moreover, you may use 2 or more types of solvents.

<Other ingredients>
The conductive composition of the present invention may optionally contain an ultraviolet absorber, an ultraviolet stabilizer, a radical scavenger, a filler, a thixotropy-imparting agent, an anti-aging agent, and an antioxidant, as long as the effects of the present invention are not impaired. agents, antistatic agents, flame retardants, thermal conductivity modifiers, plasticizers, anti-sagging agents, antifouling agents, preservatives, bactericides, antifoaming agents, leveling agents, antiblocking agents, hardeners, thickeners, Various additives such as a pigment dispersant and a silane coupling agent may be added.

<Composition of conductive composition>
A conductive wiring can be formed by applying a conductive composition.
The ratio of the binder resin in the conductive composition is less than 50% by mass, preferably 10-50% by mass, more preferably 20-35% by mass. If the amount of the binder resin is too small, the surface properties and adhesion of the conductive wiring may not be maintained.
The proportion of the conductivity-imparting agent in the conductive composition is 40 to 90% by weight, preferably 65 to 80% by weight. If the amount of the conductivity-imparting agent is too small, the electrical conductivity of the conductive wiring may become insufficient.

<Production of conductive composition>
The conductive composition can be produced by including the binder resin and the conductivity-imparting agent as essential components, and further, if necessary, by blending an organic solvent and other components and then uniformly dispersing the components. The dispersion method is carried out by dissolving the binder resin in a solvent, adding the conductive filler, and then using a disper, planetary stirring, three-roll, two-roll, paint conditioner, bead mill, or the like. The solvent to be used is not particularly limited as long as it dissolves the binder resin. Dispersion methods other than those described above may be used as long as the physical properties are not degraded. However, when using a curing agent, addition of the curing agent shall be performed after dispersion of the conductive composition. After adding the curing agent, the mixture is appropriately mixed by planetary stirring, a mix rotor, a disper, or the like. A mixing method is not particularly limited.

<Method for applying conductive composition>
The method for applying the conductive composition onto the sheet-like substrate is not particularly limited and any known method can be used.

Specific examples include a die coating method, a dip coating method, a roll coating method, a doctor coating method, a knife coating method, a spray coating method, a gravure coating method, a screen printing method or an electrostatic coating method. As a method, drying by standing, a blow dryer, a hot air dryer, an infrared heater, a far-infrared heater, etc. can be used, but the method is not particularly limited to these.
Further, after application, a rolling treatment using a lithographic press, calendar rolls, or the like may be performed.

The thickness of the conductive wiring is 30-300 μm, more preferably 50-150 μm.

<Water vapor barrier layer>
The first and second water vapor barrier layers can be obtained by vapor-depositing a non-metallic inorganic oxide on at least one side of a plastic film. It can also be used in any mode, and can protect conductive wiring from water vapor and oxygen. When two or more layers are laminated, vapor-deposited plastic films can be laminated by a conventionally known lamination method such as dry lamination, extrusion lamination, or thermal lamination.

Examples of plastic films deposited with nonmetallic inorganic oxides include polyester resin films such as polyethylene terephthalate and polynaphthalene terephthalate, polyethylene resin films, polypropylene resin films, polyvinyl chloride resin films, and fluorine resin films. , polycarbonate-based resin film, polysulfone-based resin film, poly(meth)acrylic-based resin film, nylon, and other plastic films are subjected to conventionally known PVD methods such as vacuum deposition, ion plating, and sputtering, and plasma CV. D, a material deposited using a CVD method such as microwave CVD can be used.
As the nonmetallic inorganic oxide used for vapor deposition, for example, silicon oxide or the like can be used.

The thickness of the deposited layer of the nonmetallic inorganic oxide varies depending on the material used, etc., but is preferably in the range of 50 Å to 2500 Å, more preferably in the range of 300 Å to 1200 Å.

The deposited layer of metal oxide or non-metallic inorganic oxide may be provided on at least one side of the plastic film, and may be provided on both sides. If it is provided only on one side, it is preferably provided on the side in contact with the adhesive layer (4). Furthermore, when two or more kinds of nonmetallic inorganic oxides are used in the vapor deposition, a vapor deposited film can be composed of a mixture of different kinds of materials.

<Weather resistant film layer>
The weather-resistant film layer is a plastic film that can be used outdoors for five years or longer, including in the shade. It is particularly preferred from the standpoint of alkalinity.
Olefin-based substrates, urethane-based substrates, polycarbonate-based substrates, polymethylpentene (TPX)-based substrates, etc. are excluded because they become brittle in an environment where acids and alkalis coexist and do not have long-term resistance to ultraviolet rays.
In general, the polyester resin base material is made of a polymer obtained by condensation polymerization of monomers, and is said to contain 1.6 to 2% by mass of an oligomer, which is an intermediate between the monomer and the polymer. It is easy to hydrolyze in a moist heat environment or an environment exposed to the sun, and it becomes extremely brittle. By using a solid phase polymerization method to advance the polymerization reaction to a high degree without increasing the number average molecular weight, the polymerization reaction proceeds and the oligomer content is 1.5% by mass or less, preferably 1.0% by mass. % or less, it is possible to obtain a polyester resin base material which is resistant to hydrolysis and excellent in durability, and is also available as a commercial product. Examples of commercially available products include Lumirror X10S (trade name) manufactured by Toray Industries, Inc. Here, the oligomer content can be known using a method such as nuclear magnetic resonance (NMR). When these low oligomer content polyester resin base materials are used, appearance changes such as yellowing occur when exposed to sunlight, but they do not become embrittled and the protective function is maintained, but when exposed to the shade, yellowing occurs. It can be used for 20 years or more without brittleness and embrittlement.
Polyamide resin base material is used as a base material for flexible printed circuits and has high heat resistance and high resistance to acids and alkalis. is provided, the effect of protecting the conductive layer is enhanced.
As a method of lamination to the water vapor barrier film, one side of the film can be heat-sealed, or one side of the film can be coated with an acrylic pressure-sensitive adhesive or a polyester, acrylic, or epoxy adhesive for dry lamination. After that, it is possible to stack the wiring pattern on the side of the wiring sheet on which the wiring pattern is provided so as to sandwich the wiring pattern between the films, pass it through the nip between the hot rolls, and bond it. Polyester resin, acrylic resin, fluororesin, polyamide One or both of the two heating rolls are appropriately heated to a temperature of room temperature to 250°C for a film made of a resin or vinyl chloride resin, passed through the nip between the heating rolls, and pasted to the wiring sheet to seal the conductive wiring. , water vapor, oxygen, alkali, acid, sunlight, etc. can be suppressed.

<Adhesive layer>
An acrylic pressure-sensitive adhesive or a urethane-based pressure-sensitive adhesive can be appropriately used as the pressure-sensitive adhesive.

<Adhesive layer>
As the adhesive, olefin-based, rubber-based, or polyamide-based hot-melt adhesives for extrusion lamination, polyester-based, acrylic-based, or epoxy-based adhesives for dry lamination, or the like can be appropriately used.
When these pressure-sensitive adhesive layer and adhesive layer are adjacent to the water vapor barrier layer, cracking of the water vapor barrier layer can be prevented, and mechanical deterioration due to bending of the film can be prevented.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the examples below do not limit the scope of the present invention. In addition, "parts" in the examples and comparative examples represent "mass parts".

<Method for measuring weight average molecular weight (Mw)>
Mw was measured using GPC (gel permeation chromatography) "HPC-8020" manufactured by Tosoh Corporation. GPC is liquid chromatography for separating and quantifying a substance dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size. The measurement in the present invention is performed by connecting two "LF-604" columns (manufactured by Showa Denko Co., Ltd.: GPC column for rapid analysis: 6 mm ID x 150 mm size) in series, flow rate 0.6 ml / min, column temperature The measurement was carried out at 40° C., and the weight average molecular weight (Mw) was determined in terms of polystyrene.

<Measurement of acid value>
About 1 g of a sample is accurately weighed into a stoppered Erlenmeyer flask, and dissolved in 100 ml of toluene/ethanol (volume ratio: toluene/ethanol=2/1) mixture. Phenolphthalein test solution is added to this as an indicator and held for 30 seconds. After that, titrate with 0.1N alcoholic potassium hydroxide solution until the solution becomes pale pink. The acid value was determined by the following formula (unit: mgKOH/g). Acid value (mgKOH/g) = (5.611 x a x F)/S
however,
S: Sample collection amount (g)
a: consumption of 0.1N alcoholic potassium hydroxide solution (ml)
F: Titer of 0.1N alcoholic potassium hydroxide solution

[Preparation of conductive composition for conductive wiring]
<Binder resin A>
Water-based urethane emulsion NeoRez R966 (Kusumoto Kasei Co., Ltd.) with a solid content of 33% was used.
<Synthesis of binder resin B>
Polyester polyol obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol (manufactured by Kuraray Co., Ltd. 455.5 parts of "Kuraray Polyol P-2011", Mn = 2011), 16.5 parts of dimethylolbutanoic acid, 105.2 parts of isophorone diisocyanate, and 140 parts of toluene are charged and reacted at 90°C for 3 hours in a nitrogen atmosphere. 360 parts of toluene was added to obtain a urethane prepolymer solution having an isocyanate group. Next, 19.9 parts of isophoronediamine, 0.63 parts of di-n-butylamine, 294.5 parts of 2-propanol, and 335.5 parts of toluene were mixed, and the resulting urethane prepolymer solution having an isocyanate group was obtained. 969.5 parts was added, 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 pre- A solution of binder resin B, which is a polyurethane resin, was obtained in which the total equivalent of the amino groups in the polyamino compound and the reaction terminator was 0.98 with respect to the free isocyanate groups at both ends of the polymer.

<Production of conductive composition (1)>
Conductivity-imparting agent A (expanded graphite manufactured by Nippon Graphite Co., Ltd., "LEP") was added with 7 parts of BYK's dispersant BYK 198, diluted with water as a solvent so that the final solid content was 25%, The mixture is placed in a mixer and mixed, and further placed in a sand mill for dispersion. Finally, binder resin A is added so that the solid content ratio becomes 23 parts, and finally water is added so that the solid content ratio becomes 20%. , and mixed in a mixer to obtain a conductive composition (1).

<Production of conductive compositions (2) and (3)>
Conductive compositions (2) and (3) were prepared in the same manner as the conductive composition (1), except that the conductivity-imparting agent, dispersant, binder resin, and solvent were changed as shown in Table 1. got

表１中、
ＢＹＫ１１１は、ビックケミー社製分散剤ＢＹＫ１１１を表す。
また、導電性付与剤として以下のものを用いた。
導電性付与剤Ａ：膨張化黒鉛 日本黒鉛(株)製 「ＬＥＰ」
導電性付与剤Ｂ：膨張化黒鉛 日本黒鉛(株)製 「ＣＭＸ４０」
導電性付与剤Ｃ：銀粉末 福田金属箔粉工業(株)製「ナノメルトＡｇ－ＸＦ３０１」

In Table 1,
BYK111 represents the BYK-Chemie dispersant BYK111.
Moreover, the following was used as an electroconductivity imparting agent.
Conductivity imparting agent A: Expanded graphite "LEP" manufactured by Nippon Graphite Co., Ltd.
Conductivity imparting agent B: Expanded graphite "CMX40" manufactured by Nippon Graphite Co., Ltd.
Conductivity imparting agent C: Silver powder Fukuda Metal Foil & Powder Co., Ltd. "Nanomelt Ag-XF301"

[Preparation of adhesive for adhesive layer]
<Synthesis of adhesive a>
70 parts of n-butyl acrylate, 20 parts of methyl acrylate, 2-ethyl acrylate, 20 parts of methyl acrylate, 2-ethyl 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) and replacing the air in the reaction vessel with nitrogen gas, The reaction solution was allowed to react at reflux temperature for 8 hours under a nitrogen atmosphere with stirring. After completion of the reaction, the solution was diluted with ethyl acetate to obtain a solution of acrylic copolymer a1 having a nonvolatile content of about 30% and a weight average molecular weight Mw of 1,050,000.
A reaction vessel was charged with 100 parts of toluene, and a dropping device was charged with 95 parts of n-butyl methacrylate and 5 parts of N,N-dimethylaminoethyl methacrylate. After replacing the air in the reaction vessel with nitrogen gas, the mixture was stirred. After adding dropwise for 1 hour under a nitrogen atmosphere, the reaction solution was allowed to react at reflux temperature for 8 hours. After completion of the reaction, the solution was diluted with ethyl acetate to obtain a solution of an acrylic copolymer a2 having a nonvolatile content of about 30% and a weight average molecular weight Mw of 50,000.
75 parts by weight of acrylic copolymer solution a1, 25 parts by weight of acrylic copolymer solution a2, 0.021 part of N,N,N',N'-tetraglycidyl-m-xylylenediamine as epoxy cross-linking agent, tinuvin 2.3 parts of each of 400 and Tinuvin 123 and 1.2 parts of Tinuvin 479 were added and uniformly stirred to obtain an adhesive a.

[Preparation of Laminate Films (B-1, 2) Having Water Vapor Barrier Layer]
(Preparation of Laminate Film (B-1) Having Water Vapor Barrier Layer)
PET film separator 50 μm (SP-PET01-50BU: manufactured by Mitsui Chemicals Tohcello) treated with release silicone was coated with adhesive a so that the coating amount was 30 g/m ² (dry). A film having a water vapor barrier layer was prepared by Mitsubishi Chemical Corporation Techbarrier LX (silica deposition PET, oxygen permeability: 0.4 cc/(m ² · d · atm) 25 ° C. × 80% RH, water vapor. Transmittance: 0.2 g/(m ² ·D) 40° C.×90% RH) was laminated by roll lamination and aged at room temperature for 1 week to obtain a laminate film (B-1) having a water vapor barrier layer.
(Preparation of Laminate Film (B-2) Having Water Vapor Barrier Layer)
As a water vapor barrier film, Techbarrier MX (silica deposition PET, oxygen permeability: 0.08 cc/(m ² d atm)) manufactured by Mitsubishi Chemical Corporation, which has a high water vapor barrier performance and an effect of blocking ultraviolet rays. Laminate film (B-2) was obtained in the same manner except that the temperature was changed to 25°C x 80% RH and water vapor permeability: 0.05 g/(m ² ·D) 40°C x 90% RH).

[Preparation of laminate film having weather-resistant film layer]
(Preparation of laminate film (C-1) having weather-resistant film layer)
PET film separator 50 μm (SP-PET01-50BU: manufactured by Mitsui Chemicals Tohcello) treated with release silicone was coated with adhesive a so that the coating amount was 30 g/m ² (dry). After drying for a minute, a polyvinylidene fluoride film "DX Film 14S2250" was applied as a weather resistant film by roll lamination and aged at room temperature for 1 week to obtain a laminate film (C-1) having a weather resistant film layer.

(Preparation of laminated films (C-2 to C-6) having a weather-resistant film layer)
C-2 to C-6 were obtained in the same manner as C-1 except that the weather resistant film was changed as shown in Table 2.

[Example 1]
<Production of wiring sheet (S-1)>
A slit hole of 10 mm × 100 mm is created in a 188 μm PET film, and this is placed on a sheet-like substrate A (white moisture-resistant polyethylene terephthalate film, manufactured by Toray Industries, Inc. “MX-11” 75 μm), and conductive as conductive wiring 1. After the adhesive composition (1) was applied using a doctor blade, it was dried by heating at 100° C. for 10 minutes. Furthermore, a PET film separator 50 μm (SP-PET01-50BU: manufactured by Mitsui Chemicals Tohcello) was placed on the wiring pattern, and a hydraulic roll laminator NP-500S manufactured by Taisei Laminator (hydraulic pressure 2 MPa, speed 0.5 m / min, press temperature 150 ° C.). to fabricate a conductive wiring having a thickness of 45 to 50 μm.
Next, the laminate film (B-1) having the water vapor barrier layer is pasted by roll lamination so that 5 mm of the end of the conductive wiring remains, and then the laminate film (B-1) having the water vapor barrier layer is laminated. A laminate film (C-1) having a weather-resistant film layer was adhered by roll lamination so as to cover the film (B-1) with an edge of 5 mm left, to obtain a wiring sheet (S-1). FIG. 1 is a cross-sectional view of the wiring sheet (S-1). FIG. 3 is a diagram of the wiring sheet (S-1) viewed from the laminate film (C-1) side.

[Examples 2 to 16 and Comparative Examples 1 to 10]
Wiring sheet (S-1) except that the sheet-like base material, the conductive composition, the laminate film having a water vapor barrier layer, and the laminate film having a weather resistant film layer of the wiring sheet (S-1) were changed as shown in Table 3. ) to obtain wiring sheets (S-2) to (S-16) and (SA-1) to (SA-10).
The wiring sheets (S-7) and (S-9) were also laminated with the laminate film (B-1) on the outside of the sheet-like substrate (the side facing the conductive wiring). In addition, the wiring sheets (S-8), (S-10), and (S-16) are laminate films having a water vapor barrier layer on the outside of the sheet-like substrate (the side facing the conductive wiring). (B-2) was laminated. FIG. 2 is a cross-sectional view of the wiring sheet (S-7).
However, Examples 11 to 23 are reference examples.

In Table 3, the following sheet-like substrates were used.
Sheet-like substrate A: White moisture-resistant polyethylene terephthalate film Toray Industries, Inc. “MX-11” 75 μm
Sheet-like base material B: Transparent moisture-resistant polyethylene terephthalate film Toray Industries, Inc. "X-10S"
Sheet-like base material C: Polyimide film "Kapton 500H" manufactured by Toray DuPont Co., Ltd. 125 μm

[Example 17]
<Production of wiring sheet (S-17)>
Copper foil tape No. 8323 (width 10 mm x length 100 mm) manufactured by Teraoka Seisakusho Co., Ltd. was pasted as conductive wiring 4 on sheet-like base material B (transparent moisture-resistant polyethylene terephthalate film "X-10S" manufactured by Toray Industries, Inc.) at intervals of 10 mm. to obtain a conductive trace.
Next, a laminate film (B-1) having a water vapor barrier layer was pasted by roll lamination so that 5 mm of the end of the conductive wiring remained. Furthermore, a laminate film (C-1) having a weather-resistant film layer is pasted by roll lamination so as to cover the laminate film (B-1) from above the laminate film (B-1) so that 5 mm of the edge remains, A wiring sheet (S-17) was obtained.

[Examples 18-23 and Comparative Examples 10-18]
A wiring sheet (S -18) to (S-23) and (SA-13) to (SA-18) were obtained.
The wiring sheet of the wiring sheet (S-23) was laminated with a laminate film (B-2) having a water vapor barrier layer also on the outside of the sheet-like substrate (the side facing the conductive wiring).

[Comparative Examples 19 and 20]
The wiring sheets (SA-19) and (SA-20) had a configuration in which the conductive wiring was placed on the sheet-like base material B as shown in Table 3, and no film for sealing the conductive wiring was provided thereon. I got the one of

[Evaluation of Wiring Sheet]
The obtained wiring sheets were evaluated by the following methods. Table 3 shows the evaluation results.

(Evaluation of conductivity)
The conductivity of the wiring sheet was determined by measuring the resistance value (resistance value at a length of 10 mm) at the end of the conductive layer of the wiring sheet to which the sealing material was attached using a pocket tester CDM-09N manufactured by Custom Co., Ltd. After 1500 hours in the following weather resistance test, acid resistance and alkali resistance after 2000 hours, and moist heat aging test after 3000 hours. The measurement was repeated N=2, and the average value was used for determination.
Rate of increase in volume resistance value % = {(resistance value after aging) / (initial resistance value) - 1} × 100
◎: "Increase rate of volume resistance value is less than 30% (extremely good)"
○: “Rate of increase in volume resistance value is 30 to 50% (good)”
△: “Rate of increase in volume resistance value is 50 to 500% (usable)”
×: “Increase rate of volume resistance value is 500% or more (defective)”

(Weather resistance of wiring sheet)
The weather resistance of the wiring sheet was measured using an ultra-accelerated weather resistance tester Eye UV Tester SUV-W161 (metal halide lamp type) manufactured by Iwasaki Electric. The test conditions are as follows.
12 hour cycle, irradiation time 10 hours, rest time 2 hours, shower time 10 seconds, shower interval time 1 minute Irradiation temperature 63°C
Irradiation humidity 70%
Resting temperature 70°C
Rest humidity 70%
UV illuminance 100mW/cm2

◎: Appearance changed after 1500 hours ○: Appearance changed after 1000 to 1500 hours △: Appearance changed after 500 to 1000 hours ×: Appearance changed after 500 hours

(Acid resistance of wiring sheet)
To test the acid resistance of the wiring sheet, a 0.1% hydrochloric acid aqueous solution was prepared in a 900 ml mayonnaise bottle, and the wiring sheet (1) cut into strips of 5 x 10 cm was immersed in the solution and placed in an oven at 80°C. After 2000 hours, the appearance was observed.
◎: "No change in appearance (no practical problem level)"
○: “Slight changes such as discoloration, peeling, and foaming (problem, but usable level)”
△: "There is a change in appearance about half"
×: “Most parts have changes in appearance such as discoloration, peeling, and foaming.”

(Alkali resistance test)
The alkali resistance test of the wiring sheet was carried out by preparing a 1% saturated aqueous solution of calcium hydroxide in a 900 ml mayonnaise bottle, and immersing the wiring sheet (1) in strips of 5 x 10 cm. After 2000 hours in an oven at 100°C, the appearance was observed.
◎: "No change in appearance (no practical problem level)"
○: “Slight changes such as discoloration, peeling, and foaming (problem, but usable level)”
△: "There is a change in appearance about half"
×: “Most parts have changes in appearance such as discoloration, peeling, and foaming.”
(Wet heat aging test)
A wet heat aging test of the wiring sheet was performed using an environmental tester PL-1KP manufactured by Espec. The wet heat aging conditions were set to 85° C./85% RH, and aging was performed for 3000 hours.
◎: "No change in appearance (no practical problem level)"
○: "There is a slight change in appearance such as discoloration, peeling, and foaming (problem, but usable level)"
△: "There is a change in appearance about half"
×: “Most parts have changes in appearance such as discoloration, peeling, and foaming.”

According to this example, a wiring sheet excellent in acid resistance, alkali resistance, weather resistance and salt water resistance could be provided by sealing with a barrier laminate film having a water vapor barrier layer. Silver wiring and copper wiring have good initial resistance values of 0.1 to 0.3Ω. A wiring sheet without a barrier laminate film whose appearance was significantly deteriorated by acid, alkali, or wet heat became inductive. It was found that deterioration can be prevented by In addition, the use of the B-2 film, which has a high water vapor barrier property, was more effective in improving the resistance.
When a carbon-based conductive material is used for conductive wiring, the resistance value is 10 to 50 Ω, which is higher than that of metal materials, but there is no concern that the carbon material itself will deteriorate due to acidic or alkaline aqueous solutions, and the rate of increase in resistance value is also suppressed. Therefore, it was found that a wiring sheet that can withstand long-term use can be provided.

1: Sheet-like base material layer 2: Adhesive layer or adhesive layer 3: Water vapor barrier base material layer 4: Weather resistant film layer or non-weather resistant film layer 5: Conductive wiring

Claims (5)

An insulating sheet-like substrate (1), a conductive wiring (2) arranged on the insulating sheet-like substrate, a first water vapor barrier layer (3), and a weather resistant film layer (4) wherein the conductive wiring (2) is formed by printing or coating a conductive composition containing a carbon material on the insulating sheet-like substrate (1) A wiring sheet characterized by comprising conductive wiring that has been coated. 2. The method according to claim 1, wherein the weather resistant film layer (4) contains at least one selected from the group consisting of polyethylene terephthalate resin, acrylic resin, fluororesin, polyamide resin, polyimide resin, and vinyl chloride resin. wiring sheet. Wiring sheet according to claim 1 or 2, characterized in that the water vapor barrier layer (3) contains a non-metallic inorganic oxide. Furthermore, it has an adhesive layer or an adhesive layer, and the adhesive layer or adhesive layer is adjacent to the water vapor barrier layer (3), according to any one of claims 1 to 3. wiring sheet. 5. The method according to any one of claims 1 to 4, further comprising a second water vapor barrier layer (5) on the surface of the insulating sheet-like substrate (1) facing the conductive wiring (2). wiring sheet.

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