JP2022000337A - Conductive laminate, adhesive structure using it, natural potential measurement sensor, chloride ion sensor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive laminate capable of firmly adhering to an adherend in a state of exhibiting high conductivity.
SOLUTION: The above problem is a conductive laminate of a conductive hot melt adhesive layer containing a thermoplastic resin and a conductive filler, and the volume resistivity of the conductive hot melt adhesive layer is 1 × 10 ^−. a 1 × 10 ³ less [Omega] cm or more ¹ [Omega] cm, the volume resistivity of the conductive layer is solved by the electroconductive laminate and less than ^{1 × 10 0 Ωcm 1 × 10} -5 Ωcm or more.
[Selection diagram] Fig. 1

Description

INDUSTRIAL APPLICABILITY The present invention can acquire an electrical signal inside an adherend in a state where it is easily and firmly adhered to a conductive adherend, for example, a material such as stone, stainless steel, concrete, skin, or wood. The present invention relates to an adhesive sheet for a laminated body and a method for manufacturing the same.

In recent years, with the dramatic progress of information technology, the development of devices that can acquire information more accurately, in the long term, and with low power consumption is being vigorously carried out in Japan and overseas. In particular, the breakthrough in sensor technology is tremendous, and by spreading sensors all over the place, it is possible to accurately and semi-permanently acquire information that was difficult to handle in the past and information that had to depend on on-site skill, and the sensor was attached. Information can be easily obtained by improving the fixing technology.
Against such a background, there is an increasing demand for a conductive adhesive sheet capable of easily and firmly joining and adhering a conductive material to an object and acquiring an electrical signal of the object for a long period of time. There is. With the technological progress in the field of electronics, modularization of electronic materials is being promoted, and conductive adhesive sheets are indispensable in such fields.
Further, by firmly adhering such a conductive adhesive sheet to the surface of reinforced concrete, it can be utilized as a monitoring sensor for diagnosing deterioration of reinforced concrete. However, at present, a conductive adhesive sheet that has high conductivity, adhesive strength, and durability and can be easily adhered in an outdoor environment has not been realized.

Japanese Unexamined Patent Publication No. 2001-200225 Japanese Unexamined Patent Publication No. 2002-155261

An object of the present invention is to provide a conductive laminate that can be easily and firmly adhered to an adherend in a state of exhibiting high conductivity.

As a result of diligent studies to solve the above problems, the present inventors have found that the conductive laminate shown below can be easily and strongly conductively bonded, and have completed the present invention.

That is, the present invention is a conductive laminate having at least a conductive layer and a conductive hot melt adhesive layer in contact with the conductive layer on a substrate, and the volume resistivity of the conductive hot melt adhesive layer is 1 ×. 10 ^-1 a 1 × 10 ³ less [Omega] cm or more [Omega] cm, the volume resistivity of the conductive layer is about electroconductive laminate and less than ^{1 × 10 0 Ωcm 1 × 10} -5 Ωcm or more.

The present invention also relates to the above-mentioned conductive laminated body, which is characterized in that the elastic modulus of the conductive hot-melt adhesive layer is less than 5 MPa at 25 ° C.

The present invention also relates to the above-mentioned conductive laminate, which is characterized in that a conductive layer and / or a conductive hot-melt adhesive layer is patterned.

The present invention is also characterized by having a patterned insulating hot melt adhesive layer around a patterned conductive layer and / or a patterned conductive hot melt adhesive layer. Regarding the laminate.

The present invention also relates to the above-mentioned conductive laminate, wherein the conductive layer and the conductive hot-melt adhesive layer contain a resin and a conductive filler, respectively.

Further, in the present invention, at least the conductive filler is selected from the group consisting of graphite, carbon black, carbon nanotubes, graphene, graphene oxide, silver, copper, tin, zinc, zinc oxide, nickel, manganese, and ITO. The present invention relates to the above-mentioned conductive laminate, which is characterized by being one kind.

The present invention also relates to the above-mentioned conductive laminate, wherein the conductive filler contains at least one selected from the group consisting of graphite, carbon black, carbon nanotubes, graphene, and graphene oxide.

Further, the present invention is characterized in that the resin in the conductive hot melt adhesive layer contains a styrene-based thermoplastic resin, and the resin in the conductive layer contains a phenoxy-based thermoplastic resin. Regarding.

The present invention also relates to the above-mentioned conductive laminate, wherein the conductive hot-melt adhesive layer and / or the insulating hot-melt adhesive layer has adhesiveness.

The present invention also relates to an adhesive structure characterized in that the conductive laminate and the adherend are laminated.

Further, the present invention is a natural potential sensor capable of measuring deterioration of reinforcing bars existing inside concrete through a signal obtained from a conductive laminated body.
The present invention relates to a natural potential measurement sensor characterized in that the conductive laminate is the above-mentioned conductive laminate.

Further, the present invention is a chloride ion sensor capable of measuring the chloride ion concentration inside concrete through a signal obtained from a conductive laminate.
The present invention relates to a chloride ion sensor, wherein the conductive laminate is the above-mentioned conductive laminate.

Further, the present invention is a method for manufacturing a conductive laminate having at least a conductive layer and a conductive hot melt adhesive layer adjacent to the conductive layer on the base material, and the conductive layer is formed on the base material. It has a printing step of printing the layer and a printing step of printing the conductive hot melt adhesive layer, and the volume resistivity of the conductive hot melt adhesive layer is 1 × 10 ^-1 Ωcm or more and ^{less than 1 × 10 3} Ωcm. there are a method for producing a conductive laminated body volume resistivity of the conductive layer is equal to or less than ^{1 × 10 0 Ωcm 1 × 10} -5 Ωcm or more.

According to the present invention, it is possible to provide a conductive laminate that exhibits high conductivity, adhesive strength, and durability.
Further, the above-mentioned conductive laminate can provide a sensor that can be used for a long period of time.

FIG. 1 shows a configuration example of a conductive laminated body of the present invention and an adhesive structure in which a conductive laminated body and an adherend are laminated. FIG. 2 shows a configuration example of the conductive laminate of the present invention and the adhesive structure in which the conductive laminate and the adherend are laminated. FIG. 3 shows a configuration example of the conductive laminate of the present invention and the adhesive structure in which the conductive laminate and the adherend are laminated. FIG. 4 shows a configuration example of the conductive laminate of the present invention and the adhesive structure in which the conductive laminate and the adherend are laminated. FIG. 5 shows a typical embodiment showing an installation example of the natural potential sensor of the present invention. FIG. 6 shows a typical embodiment showing an installation example of the chloride ion sensor of the present invention.

Hereinafter, embodiments of the present invention will be described.

<Conductive laminate>
The conductive laminate of the present invention is a conductive laminate having at least a conductive layer and a conductive hot melt adhesive layer in contact with the conductive layer on a base material, and has a volume resistivity of the conductive hot melt adhesive layer. there 1 × ^{10 -1} Ωcm or more 1 × 10 ³ to less than [Omega] cm, the volume resistivity of the conductive layer is equal to or less than ^{1 × 10 0 Ωcm 1 × 10} -5 Ωcm or more.

The conductive laminate composed of the conductive hot-melt adhesive layer and the conductive layer has a structure in which these layers are laminated, so that both conductivity and adhesion can be achieved at the same time. When a metal foil is used instead of the conductive laminate, the durability is low and the conductive characteristics may deteriorate over time. However, by using the conductive laminate of the present invention, even in an external environment. It can be used in a state where the conductivity is maintained for a long period of time. In particular, it is preferable that the conductive hot melt adhesive layer and the conductive layer contain a thermoplastic resin and a conductive filler.

<Conductive filler>
The conductive filler used in the present invention includes metals such as silver, gold, copper, nickel, zinc, manganese, iron, cobalt and aluminum and their alloys, zinc oxide, tin oxide-doped indium oxide (ITO) and tin oxide-doped indium oxide (ITO). FTO), tin oxide (IO), neodymium barium indium oxide, metal oxides such as indium oxide indium oxide (IZO), polythiophene-based, polypyrrole-based, polyaniline-based, oligothiophene-based organic substances, alumina, glass, etc. The surface of inorganic insulators and polymers such as polyethylene and polystyrene is coated with a conductive substance, and carbon-based materials such as carbon black, graphite, graphene, graphite, carbon nanotubes, fullerene, graphene oxide, and acetylene black can be mentioned. , Not limited to these. Further, graphite (graphite), carbon black, carbon nanotube, graphene, graphene oxide, silver, copper, tin, zinc, zinc oxide, nickel, manganese, and ITO are preferable, and graphite (graphite) is more preferable. Carbon black, carbon nanotubes, graphite, and graphene oxide. These may be used alone or in combination of two or more. Further, these fillers may have a structure in which two or more types of layers are connected by coating or the like. The conductive filler is preferably carbon-based because it is excellent in various resistances such as heat resistance, water resistance, and acid resistance. Further, since the conductive filler is dispersed in the thermoplastic resin, it is retained in the conductive laminated body without being dissociated and permeating into the adherend.

The shape of the conductive filler includes, but is not limited to, flake-like (scale-like), spherical, needle-like, fibrous, and dendritic-like. If it is desired to reduce the amount of the conductive filler added in order to strengthen the adhesive force, a flake-like (scaly) filler and a mixture of the flake-like (scaly) filler and another conductive filler are preferable.

The content ratio of the conductive filler to the entire conductive hot melt adhesive layer is not particularly limited, but from the viewpoint of adhesive strength and conductivity, carbon black, graphite and other carbon-based materials are 2 to 65% by weight. Is preferable, and more preferably 5 to 40% by weight. If it is less than 2% by weight, the conductivity may not be sufficient, and if it exceeds 65% by weight, the adhesive strength may be insufficient.

The content ratio of the conductive filler to the entire conductive layer is not particularly limited, but for carbon-based fillers such as carbon black and graphite, 10 to 80% by weight is preferable from the viewpoint of conductivity and adhesive strength. It is preferably 20 to 75% by weight, more preferably 30 to 70% by weight. If it is less than 10% by weight, the conductivity may not be sufficient, and if it exceeds 80% by weight, the adhesive strength may be insufficient. On the other hand, for metal fillers such as silver and copper, 40 to 80% by weight is preferable, and more preferably 50 to 70% by weight. If it is less than 40% by weight, the conductivity may not be sufficient, and if it exceeds 80% by weight, the adhesive strength may be insufficient.

<Thermoplastic resin>
As the thermoplastic resin, a so-called hot melt resin, which is a non-curable resin that becomes fluid at a high temperature and returns to a non-fluid state by cooling, can be used. It is also possible to use a curable resin that undergoes a curing (crosslinking) reaction after the thermoplastic resin is applied to the substrate.

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, It can contain one or more selected from the group consisting of styrene-based, phenoxy-based, ethylene-vinyl acetate-based, fluorine-based, silicone-based, and thermoplastic resins containing copolymers thereof. However, it is not limited to these resins. The thermoplastic resin is more preferably a styrene-based thermoplastic resin in the hot-melt adhesive layer and a phenoxy-based resin in the conductive layer from the viewpoint of reducing damage due to lamination, durability, weather resistance, heat resistance and adhesive strength. It is good to contain the thermoplastic resin of. The thermoplastic resin may be used alone or in combination of two or more. Further, the thermoplastic resin may use a copolymer formed by linking different monomers.

Styrene-based thermoplastic resins, specifically styrene-based elastomers, are preferably used for the conductive hot melt adhesive layer, generally have a polystyrene block and a rubber intermediate block, and the polystyrene portion is physically crosslinked ( It forms a domain) and becomes a bridging point, and the rubber block in the middle gives the product rubber elasticity. The soft segment in the middle includes polybutadiene (B), polyisoprene (I) and polyolefin elastomer (ethylene / propylene, EP), and depending on the mode of arrangement with polystyrene (S) in the hard segment, it is linear (linear type). And radial (radical type). Among the above-mentioned preferable styrene-based elastomers, in the present invention, more specifically, a styrene isoprene styrene block copolymer (SIS), a hydrogenated product of a styrene / ethylene / butylene / styrene block copolymer (SEPS), a 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 It can contain one or more selected from the group consisting of hydrogenated substances (SEEPS) of block copolymers. However, it is not limited to these resins.

The phenoxy-based thermoplastic resin is preferably used for the conductive layer, and can be generally obtained from the reaction between the phenol compound and epichlorohydrin, but a known phenoxy-based thermoplastic resin can be used. The phenoxy-based thermoplastic resin used here is not particularly limited, but is, for example, a phenoxy having a bisphenol skeleton such as bisphenol A type, bisphenol F type, bisphenol A / F type mixed type, and bisphenol S type. In addition to the based thermoplastic resin, a phenoxy-based thermoplastic resin having a naphthalene skeleton, a phenoxy-based thermoplastic resin having a biphenyl skeleton, and the like can be mentioned. The phenoxy-based thermoplastic resin preferably has a weight average molecular weight of 1000 to 100,000 from the viewpoint of handleability. It is more preferably 20000 to 80000.

<Adhesive enhancer>
As the tackifier, for example, hydrogenated terpene resin, terpene resin, hydrogenated rosin resin, rosin resin, hydrogenated hydrocarbon resin, hydrocarbon resin, epoxy resin, hydrogen addition Epoxy resin, ketone resin, hydrogenated ketone resin, polyamide resin, hydrogenated polyamide resin, elastomer resin, hydrogenated elastomer resin, phenol resin, hydrogenated Examples thereof include phenol-based resins, petroleum-based resins, hydrogenated petroleum-based resins, styrene-based resins, and hydrogenated styrene-based resins. These tackifier resins can be used alone or in combination of two or more.
Among these, a hydrogenated hydrocarbon resin is preferable from the viewpoint of durability. Since the addition of hydrogen eliminates the conjugate double bond in the intramolecular structure, deterioration due to light or heat is unlikely to occur when the conductive hot melt adhesive containing the tackifier is permanently adhered to the adherend for 10 years. The above adhesive strength can be maintained.

<Softener>
Examples of the softener include petrolatum, mineral oil, vegetable oil, animal oil and the like. Mineral oils include liquid paraffin, paraffin, paraffin-based mineral oil in which the number of carbon atoms in the paraffin chain accounts for 50% or more of the total number of carbon atoms, and naphthen-based mineral oil in which the number of carbon atoms in the naphthen ring accounts for 30 to 40% by weight of the total number of carbon atoms. And aromatic mineral oils in which the number of aromatic carbons accounts for 30% by weight or more of the total number of carbons can be mentioned. Vegetable oils and fats: olive oil, carnauba wax, rice germ oil, corn oil, southern ka oil, camellia oil, castor oil, jojoba seed oil, mink oil, eucalyptus leaf oil and the like can be mentioned. Animal fats and oils: beeswax, squalane, honey can be mentioned. In addition, mistylic acid, oleic acid, isopropyl mistyrate, zinc mistylate, octyldodecyl myriostate, glycerin triisooctanoate, octyldodecanol, hexyldecanol, diisopropyl adipate, diethyl sebacate, stearic acid, isostearic acid, crotamiton, medium chain Examples of the softening agent include fatty acids triglycerito, ethylene glycol salicylate, cetyl ethylhexarate, glycol distearate, cetearyl alcohol, cetanol, cetyl palmitate, ethylhexyl palmitate, isopropyl palmitate, and behenyl alcohol. Softeners can include plasticizers, such as dioctyl phthalate, diisodecyl phthalate, bis-2-ethylhexyl phthalate, dibutyl phthalate, dicyclohexyl phthalate, diisononinyl phthalate, tributyl acetylcitrate, Examples thereof include dioctyl adipate, diisononyl adipate, tricresyl phosphate, trioctyl trimetate and the like. These softeners can be used alone or in combination of two or more.

<Antioxidant>
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 and the like can be mentioned. The phenolic antioxidant is preferably pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and phosphorus-based antioxidant. The agent is preferably tris (2,4-di-t-butylphenyl) phosphite.

<Dispersant>
The addition of the dispersant is effective in controlling the fluidity and viscosity when the conductive hot melt adhesive layer and the conductive layer are formed by a printing / coating method, and is particularly effective when a solvent is used. The content of the dispersant can be appropriately selected depending on the purpose of use, but is preferably 10 to 300% with respect to the conductive filler. The dispersant used can be obtained as a commercially available product, and for example, DISPERBYK-102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-108, DISPERBYK-110, DISPERBYK-111, DISPERBYK-manufactured by Big Chemie Japan Co., Ltd. 130, DISPERBYK-140, DISPERBYK-150, DISPERBYK-160, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-164, DISPERBYK-165, DISPERBYK-180, DISPERBYK-190, DISPERBYK-190, DISPERBYK-190 DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2010, DISPERBYK-2012, DISPERBYK-2015, DISPERBYK-2022, DISPERBYK-2055, DISPERBYK-2096, DISPERBYK-2155, DISPERBYK- 1000, DISPERPLAST-1018, DISPERPLAST-1018, DISPERPLAST-1042, DISPERPLAST-1150 and the like can be mentioned, but the present invention is not limited thereto.

<Other ingredients>
Various additives can be appropriately added to the conductive hot-melt adhesive layer and the conductive layer as long as the effects of the present invention are not impaired. For example, curing of polyisocyanates, epoxy resins, polycarbodiimide compounds, amine compounds, etc. from the viewpoints of reduction of curing shrinkage rate, reduction of thermal expansion rate, improvement of dimensional stability, improvement of elastic modulus, viscosity adjustment, strength improvement, toughness improvement, etc. Agents and organic or inorganic fillers can be blended. Such fillers may be composed of materials such as polymers, ceramics, metal salts, and dyes. The shape thereof is not particularly limited, and may be, for example, in the form of particles or in the form of fibers. In addition, a silane coupling agent, a titanate coupling agent, a flame retardant, a storage stabilizer, and an antioxidant are used to adjust the leveling property with the substrate, adjust the coatability during coating printing, and improve the adhesiveness. , Metal inactivating agents, UV absorbers, thixotropy-imparting agents, leveling agents, dispersion stabilizers, fluidity-imparting agents, defoaming agents, coloring materials and the like can also be added.

<Conductive hot melt adhesive layer>
The method for producing the conductive hot melt adhesive layer of the present invention is not particularly limited, but an example is shown below. In addition to the above-mentioned conductive filler, a thermoplastic resin and, if necessary, a softener, a tackifier, an antioxidant, and other optional components are mixed to form a mixture. The mixture is dispersed by a known disperser to form a dispersion, but the order of mixing is not particularly limited, and a mixture of a dispersion in which a thermoplastic resin, a softener, and a tackifier are dispersed in advance and a conductive filler is used. It may be a dispersion in which the above is dispersed. Examples of the disperser include a roll mill such as a two-roll and three-roll mill, a ball mill, a ball mill such as a vibration ball mill, a paint conditioner, a continuous disc type bead mill, a bead mill such as a continuous annular type bead mill, and a vanbury mixer and a kneader. , A melting pot equipped with a stirrer, a uniaxial or biaxial extruder, and the like. Then, it can be obtained through a heating / melting step of heating and mixing these, a melting step of dissolving them in an appropriate solvent and stirring and mixing them, and then a printing / coating process described later. The conductive hot-melt adhesive layer used in the present invention can be obtained by using a solvent-free heat-melting step from the viewpoint of complication of the process due to solvent removal and the accompanying cost increase, and from the viewpoint of adverse effects on the global environment due to the use of solvent. I can do things. Further, since the conductive hot melt adhesive layer used in the present invention has extremely low fluidity when it contains a carbon-based filler, a solvent is used in consideration of coatability, printability, and uniform dispersibility. It is preferable to include the above-mentioned steps. The conductive hot-melt adhesive layer used in the present invention can be used only with a conductive filler and a thermoplastic resin, but from the viewpoint of imparting fluidity, tackiness and oxidative stability, a softening agent, a tackifier, an antioxidant and a dispersion. It is preferable to include the agent. The thickness of the conductive hot melt adhesive layer used in the present invention is not particularly limited, but is preferably 10 to 500 μm, more preferably 50 to 400 μm, and even more preferably 100 to 300 μm. The conductive hot melt adhesive layer used in the present invention is used by being arranged on the surface of the adherend. The conductive hot-melt adhesive layer used in the present invention may be simply attached directly to the adherend, but after being attached to the surface of the adherend, it can be melted by heating, cooled and solidified. Therefore, it adheres to the surface of the adherend and is stably held. Further, since the conductive hot melt adhesive layer fills the voids on the surface of the adherend, the contact resistance is suppressed.
Further, it is preferable that the conductive hot melt adhesive layer has adhesiveness for the convenience of adhesion to the adherend.

<Conductive layer>
The method for producing the conductive layer of the present invention is not particularly limited, but an example is shown below.
The conductive layer is made into a mixture by mixing a resin and other, if necessary, a softener, a tackifier, an antioxidant, a dispersant, and other optional components in addition to the above-mentioned conductive filler. As the resin, a resin such as a thermoplastic resin or a thermosetting resin is used, but it is preferable to use a thermoplastic resin from the viewpoint of flexibility. Although it is possible to ensure high conductivity by using a metal filler such as aluminum or copper for the conductive layer, it is preferable to use a conductive layer in which a resin and a conductive filler are mixed from the viewpoint of durability. The thickness of the conductive layer used in the present invention is not particularly limited, but is preferably 5 to 100 μm, and more preferably 10 to 50 μm.
The mixture is dispersed by a known disperser to form a dispersion. Examples of the disperser include a roll mill such as a two-roll and three-roll mill, a ball mill, a ball mill such as a vibration ball mill, a paint conditioner, a continuous disc type bead mill, a bead mill such as a continuous annular type bead mill, and a vanbury mixer and a kneader. , A melting pot equipped with a stirrer, a uniaxial or biaxial extruder, and the like. Then, these can be obtained through a solvent-type step of dissolving them in an appropriate solvent and stirring and mixing them, followed by a printing / coating process described later.

<Insulating hot melt adhesive layer>
The method for producing the insulating hot melt adhesive layer of the present invention is not particularly limited, but an example is shown below. The thermoplastic resin is mixed with a softener, a tackifier, an antioxidant and other optional components used as necessary to obtain a mixture. The mixture is mixed by a known disperser or agitator to obtain a mixture, but the order of mixing is not particularly limited. Examples of the disperser or agitator include a roll mill such as a two-roll or three-roll mill, a ball mill such as a ball mill or a vibrating ball mill, a paint conditioner, a continuous disc type bead mill, a bead mill such as a continuous annular type bead mill, and the like. Examples include a mixer, a kneader, a melting pot equipped with a stirrer, or a uniaxial or biaxial extruder. Then, it can be obtained through a heating and melting step of heating and mixing these, a solvent type step of dissolving and stirring and mixing in an appropriate solvent, and then a printing and coating process described later. The insulating hot-melt adhesive layer used in the present invention can be obtained by using a solvent-free heat-melting step from the viewpoint of complication of the process due to solvent removal and the accompanying cost increase, and from the viewpoint of adverse effects on the global environment due to the use of solvent. I can do things. Further, the insulating hot melt adhesive layer used in the present invention preferably includes a step using a solvent in consideration of film thickness controllability, coatability, and printability. Although the insulating hot-melt adhesive layer used in the present invention can be used only with a thermoplastic resin, it is preferable to include a softener, a tackifier, and an antioxidant from the viewpoint of imparting fluidity, adhesiveness, and oxidation stability. .. The thickness of the insulating hot melt adhesive layer used in the present invention is not particularly limited, but is preferably 10 to 500 μm, more preferably 50 to 400 μm, and even more preferably 100 to 300 μm. The insulating hot melt adhesive layer used in the present invention is effective when the conductive hot melt adhesive layer does not have adhesiveness or adhesiveness, and instead of the conductive hot melt adhesive layer, hot melt is exhibited. By imparting adhesiveness or adhesiveness to the adhesive layer, it becomes easy to arrange the conductive laminate on the surface of the adherend. The insulating hot melt adhesive layer used in the present invention is arranged and used on the surface of the adherend.
The insulating hot-melt adhesive layer used in the present invention may be simply attached directly to the adherend by utilizing the adhesiveness, but after being attached to the surface of the adherend, it is melted by heating and cooled. Can be solidified. Therefore, it adheres to the surface of the adherend and is stably held.
It is preferable that the volume resistivity of the 1 × 10 ⁵ Ω · cm or more in constituting the insulating hot melt adhesive layer. Further, it is more preferable that the volume resistance value of the insulating hot-melt adhesive layer is 1 × 10 ¹⁰ Ω ・ cm or more, and it is preferable that ^{the volume resistance value is 1 × 10 15} Ω ・ cm or more ^{and less than 1 × 10 20} Ω ・ cm. More preferred.

<Conductive laminate>
As shown in FIG. 1, the conductive laminate of the present invention can be used as a conductive laminate by forming a conductive layer on one side of a base material and forming a conductive hot melt adhesive layer on the conductive layer. can. Further, as shown in FIG. 2, the conductive laminate may have a sealing layer. Further, as shown in FIG. 3, by forming an insulating hot melt adhesive layer around the conductive layer and the conductive hot melt adhesive layer formed on the same base material, it can be used as a conductive laminate. Can be done. Further, as shown in FIG. 4, the wiring provided in the natural potential sensor or the chloride ion sensor may be connected to the conductive laminate.
Examples of the method for forming the conductive layer include a coating / printing method, and the method is not particularly limited. The coating methods include 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, and dip. Examples include a coating method, a gravure coat coating method, a curtain spray coating method, a bead coating method, and a hot melt roll coater spin coat coating method. The printing methods include an inkjet printing method, a spray printing method, a roll coat printing method, and a doctor roll printing method. , Doctor blade printing method, curtain coat printing method, slit coat printing method, screen printing method, reverse printing method, push coat printing method, slit coater printing method, stencil 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 decompression methods. Although the drying conditions depend on the film thickness and the selected organic solvent, hot air heating at about 60 to 200 ° C. is usually used. The thickness of the conductive layer is not particularly limited, but is preferably 5 to 50 μm. The conductive layer can also be crosslinked by heating or irradiation with ultraviolet rays.
Examples of the method for forming the conductive hot melt adhesive layer include a coating / printing method, and the method is not particularly limited. The coating methods include 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, and dip. Examples include a coating method, a gravure coat coating method, a curtain spray coating method, a bead coating method, and a hot melt roll coater spin coat coating method. The printing methods include an inkjet printing method, a spray printing method, a roll coat printing method, and a doctor roll printing method. , Doctor blade printing method, curtain coat printing method, slit coat printing method, screen printing method, reverse printing method, transfer printing method, push coat printing method, slit coater printing method, stencil 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 decompression methods. Although the drying conditions depend on the film thickness and the selected organic solvent, hot air heating at about 60 to 200 ° C. is usually used. The thickness of the conductive hot melt adhesive layer is preferably 50 to 400 μm. The conductive hot melt adhesive layer can also be crosslinked by heating or irradiation with ultraviolet rays. When the base material is not required, the base material may be peeled off after forming a conductive laminate similar to the above by using a peelable base material.

Examples of the method for forming the conductive hot-melt adhesive layer or the insulating hot-melt adhesive layer include a coating / printing method, and the method is not particularly limited. The coating methods include 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, and dip. Examples include a coating method, a gravure coat coating method, a curtain spray coating method, a bead coating method, and a hot melt roll coater spin coat coating method. The printing methods include an inkjet printing method, a spray printing method, a roll coat printing method, and a doctor roll printing method. , Doctor blade printing method, curtain coat printing method, slit coat printing method, screen printing method, reverse printing method, transfer printing method, push coat printing method, 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 decompression methods. Although the drying conditions depend on the film thickness and the selected organic solvent, hot air heating at about 60 to 200 ° C. is usually used. The thickness of the conductive hot-melt adhesive layer or the insulating hot-melt adhesive layer is preferably 50 to 400 μm. The conductive hot melt adhesive layer or the insulating hot melt adhesive layer can also be crosslinked by heating or irradiation with ultraviolet rays. When the base material is not required, the base material may be peeled off after forming a conductive laminate similar to the above by using a peelable base material.
When patterning a conductive layer, a conductive hot-melt adhesive layer, or an insulating hot-melt adhesive layer, the above-mentioned various printing methods can be used.

<Base material>
The base material is selected from the group consisting of a resin sheet, paper, and an aluminum sheet (aluminum foil). For example, the resin sheet includes polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polycarbonate resins, polyarylate resins, acrylic resins, polyphenylene sulfide resins, polystyrene resins, and vinyl resins. , Vinyl chloride-based resin, polyimide-based resin, epoxy resin, polyethylene, polypropylene, poolinolbornene and other polyolefin-based resins and the like, and examples thereof include resin sheets formed from resins. Further, a laminate in which a metal is laminated on these sheets may be used, and for example, a laminate in which a metal is laminated on a polyethylene terephthalate (PET) sheet may be used. In addition, since the base material may be deformed by heat, a base material having high heat resistance such as a polyimide sheet, a polyethylene naphthalene sheet, a polynaphthalene sheet, a propylene sheet, a silicone resin sheet, or a base material whose heat resistance is improved by filling with a filler. Is preferable.

<Adhesive structure>
The surface of the conductive hot melt adhesive layer of the conductive laminate is attached and installed on the adherend, and the adherend is not particularly limited, but using an iron, a heater, a heating wire, hot air, an infrared heater, an IH heating device, or the like. An adhesive structure can be manufactured by melting the conductive hot-melt adhesive layer above and joining the conductive hot-melt adhesive layer and the adherend.

<Subject>
Adhesives are plastic, paper, paper-plastic composites, silver, stainless steel, copper, iron, aluminum, alloys, minerals, non-ferrous metals, concrete, mortar, slate, tiles, paving materials, skin, wood, cloth. , Leather, rubber, cork, glass, etc. The thickness of the adherend of the present invention is preferably 1 mm or more.
The type of the adherend used in the present invention is not particularly limited, but as described later, it contains a large amount of electrolytes such as chloride ion, sodium ion and calcium ion and water, and facilitates reception of signals from the inside. , Concrete, mortar are preferred.
The concrete mortar described here is a lump of a paste made by adding water to cement and mixing it over time, and contains fine aggregate such as sand and coarse aggregate such as gravel as aggregate. May be good. Concrete is hardened by the dissolution and precipitation reaction of cement. Cement is composed of elements such as calcium, silicon, aluminum and iron. When in contact with water, calcium ions dissolve and the calcium ions in the aqueous solution increase. The main components, silicic acid (SiO ₂ ) and alumina (Al ₂ O ₃ ), exist as stable substances (polymers) in which their ions are polymerized with each other, and do not react with calcium ions. However, in cement, silicate ion and aluminum ion (alumina-ion) are relatively easy to react and exist as a monomer, and when the surrounding calcium ion is leached out, it dissolves in the solution and calcium ion. It reacts with water molecules to form cement hydrate (CSH: ettringite) that is difficult to dissolve in water, and excess calcium ions are precipitated as calcium hydroxide. The hydrate particles bind to each other and cure begins.
Bonds between particles are considered to be retained by intermolecular attractive force or hydrogen bonds, and unlike calcium hydroxide, CSH is a fine bond of 0.1 μm or less, and particles per unit volume. Since the bonding area between them is extremely large, it exerts a high bonding force and exhibits the strength of the cured product. The concrete layer of the present invention includes cement hardened by mixing cement and water, mortar hardened by mixing cement, water and fine aggregate (sand), and cement, water and aggregate (fine aggregate (fine aggregate (fine aggregate)). Concrete or the like obtained by mixing (sand) and coarse aggregate (gravel)) can be used.

<Natural potential sensor>
In order to determine the corrosion of steel materials such as reinforcing bars arranged in a concrete structure, long-term monitoring by constructing a sensor system is necessary. A natural potential measurement method is known as a method for determining corrosion of steel materials such as reinforcing bars of a concrete structure. The natural potential measurement method is a method for electrochemically determining the corrosion of a steel material by measuring the potential of the steel material that changes due to corrosion. As shown in FIG. 5, the conductive laminate of the present invention is attached to concrete and the potential difference between the conductive laminate and the reinforcing bar is measured to detect the progress of corrosion of the reinforcing bar, which can be used as a natural potential sensor. Will be. Further, by using the conductive laminate of the present invention, it is possible to construct a natural potential sensor system capable of stably and long-term contact with high electrical conductivity.
The natural potential sensor of the present embodiment is a preparatory step for preparing the natural potential sensor provided with the conductive laminate according to the present invention, and an electric wire connection for electrically connecting the wiring provided in the natural potential sensor to the steel material. It has a step, a bonding step of adhering the conductive laminate provided with the natural potential sensor to the surface of the concrete structure, and a potential difference detection step of detecting the potential difference between the conductive laminate and the steel material. The bonding step includes a step of heating and melting the conductive hot melt bonding layer or the insulating hot melt bonding layer of the conductive laminate.

<Chloride ion sensor>
In order to estimate the state of metals such as reinforcing bars arranged in concrete structures, long-term monitoring of chloride ion concentration using a chloride ion sensor is required. A conductive method is known as one of the methods for measuring the chloride ion concentration in a concrete structure. Generally speaking, the conductive method measures the impedance of the concrete structure, the phase angle peak frequency of the impedance, etc. in a state where an alternating current is passed through the target concrete structure, and the moisture content of the concrete structure, etc. It is a method of calculating the chloride ion concentration in combination with the information of.
As shown in FIG. 6, the conductive laminates of the present invention are arranged on the surface of a concrete structure at intervals from each other, and an alternating current is provided between at least a pair of conductive laminates and the at least pair of conductive laminates. By measuring the impedance in a state where an electric current is passed, the chloride ion concentration in the concrete structure can be calculated, and this can be used as a chloride ion sensor.
In the chloride ion sensor of the present embodiment, the preparation step of preparing the chloride ion sensor provided with the conductive laminate according to the present invention and the wiring provided in the chloride ion sensor are electrically connected to the conductive laminate. The electric current connection step of connecting to the above, the bonding step of adhering the conductive laminate provided with the chloride ion sensor to the surface of the concrete structure, and at least a pair of conductive laminates provided with the chloride ion sensor. It has a bonding step of adhering to the surface of a concrete structure and a measuring step of measuring an impedance in a state where an alternating current is passed through the concrete structure between at least a pair of conductive laminates. Includes a step of adhering to a concrete structure by heating and melting the conductive hot melt adhesive layer or the insulating hot melt adhesive layer.

<Resistivity>
In forming the conductive hot melt adhesive layer, the volume resistivity is preferably set to a value ^{of 1 × 10 -1} Ω · cm or more ^{and less than 1 × 10 3 Ω · cm.} The reason for this is that a suitable signal can be received from the adherend as long as the volume resistivity of the conductive hot-melt adhesive layer is within such a range. It is more preferable that the volume resistivity of the conductive hot-melt adhesive layer with 1 × 10 ⁰ Ω · cm to 1 × values below 10 ³ Ω · cm, a value less than ¹ × 10 1 Ω · cm Is even more preferable.
It is preferable that the volume resistivity of the 1 × ^{10 -5} 1 × ^{10 0} value less than Ωcm or more Ωcm in constituting the conductive layer. The reason for this is that the signal received from the conductive hot-melt adhesive layer can be received without being attenuated as long as the volume resistivity of the conductive layer is within such a range. Therefore, it is preferable that the volume resistivity of the conductive layer and the value of less than 1 × 10 ⁰ Ω · cm, and more preferably a value of less than 1 × 10 ^-1 Ω · cm. The detailed measurement method of the volume resistivity will be specifically described in Examples.

<Adhesive strength>
The adhesive strength value of the conductive laminate varies depending on the adherend, but the preferable range is 2N / 25mm or more and less than 40N / 25mm, and more preferably 10N / 25mm or more and less than 30N / 25mm. The detailed measurement method of the adhesive strength will be specifically described in Examples.

<Elastic modulus>
The elastic modulus of the conductive hot-melt adhesive layer varies depending on the resin type or the blending amount with the filler, but it is less than 5.0 MPa because the elastic modulus affects the followability to the adherend and the flexibility. It is preferably present, and more preferably less than 1.0 MPa.

<Durability>
Since it is important to maintain electrochemical stability even in an outdoor environment for the durability of the conductive laminate, the durability was evaluated under salt spray conditions. The detailed measurement method will be specifically described in Examples.

Hereinafter, the present invention will be described 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 conductive filler]
Each filler powder was mixed in the number of copies shown in Table 1 to obtain conductive fillers 1 to 21.

[Preparation of conductive hot melt adhesive layer]
In three rolls, 28 parts of SIS1 as a thermoplastic resin, 7 parts of a softener 1 as a softener, 35 parts of a tackifier 4 as a tackifier, 1 part of an antioxidant 1 and a conductive filler 1 30 parts were added and kneaded for 30 minutes, and the obtained kneaded product was stencil-printed on a substrate to obtain a conductive hot-melt adhesive layer 1.
The conductive hot-melt adhesive layers 2 to 69 were prepared in the same manner as in the preparation of the conductive hot-melt adhesive layer 1 except that the raw material and the composition ratio were changed as described in Table 2. A polyimide film was used as the base material.

[Preparation of conductive layer]
In three rolls, 45 parts of phenoxy 1 as a thermoplastic resin, 55 parts of a conductive filler 1 as a conductive filler, and if necessary, a solvent, a dispersant, and an antifoaming agent were added and kneaded for 30 minutes, and the obtained kneading was performed. The conductive layer 1 was obtained by screen-printing an object on a substrate.
The conductive layers 2 to 8 were adjusted in the same manner as the adjustment of the conductive layer 1 except that the raw material and the composition ratio were changed as described in Table 3. A polyimide film was used as the base material.

[Preparation of insulating hot melt adhesive layer]
In 3 rolls, 28 parts of SIS1 as a thermoplastic resin, 7 parts of a softener 1 as a softener, 35 parts of a tackifier 4 as a tackifier, and 1 part of an antioxidant 1 are added and kneaded for 30 minutes. Then, the obtained kneaded material was stencil-printed on the substrate to obtain an insulating hot-melt adhesive layer 1.
The insulating hot-melt adhesive layers 2 to 3 were prepared in the same manner as in the preparation of the insulating hot-melt adhesive layer 1 except that the raw materials and the composition ratio were changed as described in Table 4. A polyimide film was used as the base material.

[Manufacturing of conductive laminated body sheet]
<Example 1>
The conductive hot-melt adhesive layer 1 and the conductive layer 1 obtained by the above-mentioned production of the conductive hot-melt adhesive layer and the production of the conductive layer are laminated in the order of the base material, the conductive layer 1, and the conductive hot-melt adhesive layer 1 by printing. Example 1 (conductive laminated body sheet 1) was obtained.
Examples 2 to 73, the same method as in the production of Example 1 except that the structure inside the conductive laminate (combination of the conductive hot melt adhesive layer and the conductive layer) was changed as described in Table 5. Comparative Examples 1 to 6 were adjusted. A polyimide film was used as the base material.
<Example 74>
The conductive hot-melt adhesive layer 1 and the conductive layer 1 obtained by the above-mentioned preparation of the conductive hot-melt adhesive layer and the production of the conductive layer are laminated in the order of the base material, the conductive layer 1, and the conductive hot-melt adhesive layer 1 by printing. Further, Example 74 (conductive laminate sheet 74) in which the insulating hot-melt adhesive layer 1 obtained by producing the insulating hot-melt adhesive layer 1 was formed on a substrate by printing was obtained.
In the same manner as in the production of Example 74, except that the composition inside the conductive laminate (combination of the conductive hot melt adhesive layer, the conductive layer and the insulating hot melt adhesive) was changed as described in Table 5. Examples 75-77 were adjusted. A polyimide film was used as the base material.

The abbreviations for the thermoplastic resins, tackifiers, softeners, and other components shown in Tables 1 to 4 are shown below.

<Thermoplastic resin>
・ SEBS1: Clayton Co., Ltd. Product name: G1652
・ SEBS2: Clayton Co., Ltd. Product name: G1726
・ SEBS3: Clayton Co., Ltd. Product name: G1650
・ SEBS4: Clayton Co., Ltd. Product name: G1651
・ SBS1: Clayton Co., Ltd. Product name: D0243
・ SBS2: Clayton Co., Ltd. Product name: D4433
・ SIS1: Clayton Co., Ltd. Product name: D1117
・ SIS2: Clayton Co., Ltd. Product name: D1114
・ SEPS1: Kuraray Co., Ltd. Product name: SEPTON 2063
・ SEPS2: Kuraray Co., Ltd. Product name: SEPTON 2005
・ SEPS3: Kuraray Co., Ltd. Product name: SEPTON HG-252
・ Phenoxy 1: Mitsubishi Chemical Corporation Product name: JER1256
・ Olefin 1: Ube Maruzen Polyethylene Co., Ltd. Product name: UBEBOND F1100 ・ Olefin 2: Toyobo Co., Ltd. Product name: PMAH3000P
・ Polyamide 1: Henkel Co., Ltd. Product name: PA6858
-Polyamide 2: Arkema Co., Ltd. Product name: Platamide M2519
・ Polyester 1: Toyobo Co., Ltd. Product name: Byron 200
・ PVC1: Mitsubishi Chemical Corporation Product name: Sunplane FG40EA (polyvinyl chloride)
・ EVA1: Mitsui DuPont Polychemical Co., Ltd. Product name: Evaflex V5733 (ethylene vinyl acetate)
・ EPDM1: JSR Corporation Product name: EP96 (ethylene, propylene, diene rubber)

<Adhesive enhancer>
・ Adhesive enhancer 1: Arakawa Chemical Co., Ltd. Product name: P-100
・ Adhesive enhancer 2: Harima Chemicals, Inc. Product name: Haritac F
・ Adhesive enhancer 3: Yasuhara Chemical Co., Ltd. Product name: YS Polystar T30
・ Adhesive enhancer 4: Arakawa Chemical Co., Ltd. Product name: P-90

<Softener>
・ Softener 1: Idemitsu Kosan Co., Ltd. Product name: Diana Process Oil NS90S
・ Softener 2: Idemitsu Kosan Co., Ltd. Product name: Diana Process Oil PW90
・ Softener 3: Nippon Sun Oil Co., Ltd. Product name: SUNPUREN100
・ Softener 4: Fujifilm Wako Pure Chemical Industries, Ltd. Product name: Dicyclohexylphthalate

<Other ingredients>
・ Liquid rubber 1: Kuraray Co., Ltd. Product name: Kuraray LIR290
-Antioxidant 1: BASF Product name: Irganox 1010
-Copper foil: AS ONE Corporation (size 100 x 300 x 0.03 mm)

The abbreviations of the conductive fillers shown in Table 1 are shown below.
・ Filler 1: SEC Carbon Co., Ltd. Product name: SGO-10 (graphite)
-Filler 2: CABOT Co., Ltd. Product name: VULCAN XC-72R (carbon black)
・ Filler 3: Lion Specialty Chemicals Co., Ltd. Product name: EC300J (carbon black)
・ Filler 4: Lion Specialty Chemicals Co., Ltd. Product name: EC200L (carbon black)
・ Filler 5: Lion Specialty Chemicals Co., Ltd. Product name: EC600JD (carbon black)
-Filler 6: Nippon Graphite Industry Co., Ltd. Product name: CMX-100 (graphite)
・ Filler 7: Nippon Graphite Industry Co., Ltd. Product name: LEP (graphite)
-Filler 8: OCSiAl Product name: TUBALL SWCNT (CNT)
・ Filler 9: ITEC Co., Ltd. Product name: iGurafen-α (graphene)
・ Filler 10: Fukuda Metal Foil Powder Industry Co., Ltd. Product name: Ag-XF301S
・ Filler 11: Taimei Chemicals Co., Ltd. Product name: Thai Micron TM-DA

The following tests were performed using the obtained layer.

1. 1. Measurement of volume resistivity (conductive hot melt adhesive layers 1 to 69)
The laminate of the layer and the base material obtained by the conductive hot melt adhesive layers 1 to 69 was cut into 1.5 cm × 3 cm, and a low resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd .: Lorester GX MCP-T700). The volume resistivity of the conductive hot-melt adhesive layer was measured using. Evaluation was performed on a three-point scale. If the evaluation is "1" or "2", this claim is satisfied.

1: a volume resistivity of 1 × ^{10 -1} [Omega] cm or more 1 × 10 ⁰ [Omega] cm less than 2: volume resistivity of 1 × 10 ⁰ [Omega] cm or more 1 × 10 ³ [Omega] cm less than 3: a volume resistivity of 1 × 10 ³ [Omega] cm or more

2. 2. Measurement of volume resistivity (conductive layers 1 to 8)
The laminate of the conductive layer and the base material obtained in the conductive layers 1 to 8 was cut into 1.5 cm × 3 cm, and a low resistivity meter (manufactured by Mitsubishi Chemical Analytec Co., Ltd .: Lorester GX MCP-T700) was used. The volume resistivity of the conductive layer was measured. Evaluation was performed on a three-point scale. If the evaluation is "1", this claim is satisfied. A commercially available copper foil was used for the conductive layer 8.

1: resistivity of 1 × ^{10 -5} [Omega] cm or more 1 × 10 ⁰ [Omega] cm less than 2: resistivity of 1 × 10 ⁰ [Omega] cm or more 3: resistivity of less than 1 × ^{10 -5} [Omega] cm

3. 3. Measurement of elastic modulus (conductive hot melt adhesive layers 1 to 69, insulating hot melt adhesive layers 1 to 3)
The tensile test of the conductive hot-melt adhesive layer and the insulating hot-melt adhesive layer was measured using a tensile tester EX-SX manufactured by Shimadzu Corporation. As a measuring method, a sheet obtained by the conductive hot-melt adhesive layers 1 to 69 and the insulating hot-melt adhesive layers 1 to 3 cut into 5 mm × 1 mm × 24 mm was used as a measurement sample and measured at 25 ° C. After installing the sample, the crosshead speed was set to 50 mm / min. The crosshead displacement and the load history immediately after breakage were measured, and the strain in the longitudinal direction of the measurement sample was measured using a strain gauge. The elastic modulus was calculated from the obtained stress-strain diagram.

⊚: Elastic modulus less than 1 MPa ○: Elastic modulus 1 MPa or more and less than 5 MPa ×: Elastic modulus 5 MPa or more

4. Measurement of resistance value (Examples 1 to 77, Comparative Examples 1 to 6)
If there is a base material, the conductive laminate of the conductive layer (thickness 5 to 30 μm) and the conductive hot melt adhesive layer (thickness 50 to 200 um) obtained in Examples 1 to 77 and Comparative Examples 1 to 6 is used as a base. Peel it off from the material to make a two-layer free film, cut it into 4 cm squares, apply probes to the conductive hot melt adhesive layer and the conductive layer on the back side, respectively, and use a digital multimeter (manufactured by Keysight Technology Co., Ltd .: 34410A). The resistance value in the conductive laminate was measured by the 4-terminal method.
The evaluation was performed in three stages according to the following.

⊚: Resistance is 1Ω or more and less than 100Ω ○: Resistance is 100Ω or more and less than 1000Ω ×: Resistance is 1000Ω or more

5. Measurement of adhesive strength (Examples 1 to 77, Comparative Examples 1 to 6)
The adhesive strength of the conductive laminate was determined using a tensile tester EX-SX manufactured by Shimadzu Corporation. The measurement sample is prepared in the order of the conductive hot-melt adhesive layer (thickness 50 to 200 μm), the conductive layer (5 to 30 μm), and the base material obtained in Examples 1 to 77 and Comparative Examples 1 to 6. The surface of the conductive hot-melt adhesive layer is attached to various adherends of 7 cm x 7 cm (in the case of concrete, the surface has been pre-treated with a grinder), and a press with a size of 3 cm x 7 cm from the top. This was done by pressing and adhering the plates at a temperature of 200 ° C. for 1 minute while applying a pressure of 0.1 MPa. After the heating was completed, the sample was left to stand for 24 hours until it returned to room temperature, and used as a measurement sample. The measuring method was to adjust the measurement sample in which the conductive laminate adhered to the adherend so that the width was 25 mm, and set the edge of the sheet at a 90 degree angle and the speed at 50 mm / min. The adhesive strength was calculated from the load when the product was peeled off, and the evaluation was performed in three stages according to the following.

⊚: Adhesive strength is 10N or more ○: Adhesive strength is 2N or more and less than 10N ×: Adhesive strength is less than 2N

Grinder used: Monotaro Slim Disc Grinder (MRO-100DG)
Heat press machine used: TP-701B

6. Evaluation of durability (Examples 1 to 77, Comparative Examples 1 to 6)
To determine the durability of the conductive laminate, a conductive laminate in which a conductive hot-melt adhesive layer having a width of 1 cm and a length of 6 cm is overlapped with a conductive layer having a width of 1 cm and a length of 10 cm is produced, and this is subjected to a composite cycle test. Deterioration was promoted by placing it in an environment, the change in resistance value after one week was calculated, and evaluation was performed in three stages according to the following.

⊚: Resistance value change rate is less than 1% 〇: Resistance value change rate is 1% or more and less than 10% ×: Resistance is 10% or more The combined cycle test method is the automobile standard JASO M609, which is an organization standard of the Society of Automotive Engineers of Japan. I went based on.

7. Fabrication and evaluation of natural potential sensor (Examples 1 to 77, Comparative Examples 1 to 6)
In the preparation of the measurement sample, the conductive laminate obtained in Examples 1 to 77 and Comparative Examples 1 to 6 was applied to the concrete surface of the reinforced concrete in which the rust of the reinforcing bar portion was progressing, and the conductive hot melt adhesive layer was used. A surface (thickness 200 μm) was attached, and the surface was adhered to the concrete surface by pressing it on a flat plate for 1 minute while applying a pressure of 0.1 MPa in a state of being heated to 200 ° C. from above. After the heating was completed, the sample was left to stand for 24 hours until it returned to room temperature, and used as a measurement sample. By connecting a voltmeter between the conductive laminate and the wiring connected to the reinforcing bar in concrete, natural potential measurement was made possible. The natural potential sensor capable of judging the progress of rebar corrosion was evaluated by setting ◯ when the potential measured value was -100 mV or less and × when the potential measured value was -100 mV or more. A digital multimeter 34465A manufactured by Keysight Technology Co., Ltd. was used for the natural potential measurement.

8. Fabrication and evaluation of chloride ion sensor (Examples 1 to 77, Comparative Examples 1 to 6)
In manufacturing the chloride ion sensor, two types of concrete structures containing 1.0 kg and 10 kg per ^{1 m 3 of chloride were manufactured.} The measurement samples were prepared by placing the two conductive laminates obtained in Examples 1 to 77 and Comparative Examples 1 to 6 on the surface of the conductive hot melt adhesive layer (thickness 200 μm) on the concrete surface at an interval of 10 cm. They were attached so as to form a pair separated from each other, and further adhered to the concrete surface by pressing with a flat plate for 1 minute while applying a pressure of 0.1 MPa in a state of being heated to 200 ° C. After the heating was completed, the sample was left to stand for 24 hours until it returned to room temperature, and used as a measurement sample. AC impedance can be measured by connecting a LCR meter (impedance measuring instrument) between the wiring connected to one conductive laminate and the other conductive laminate. The AC impedance value when using a ^{concrete structure containing 10.0 kg per 1 m 3 of} chloride is smaller than the AC impedance value when using a concrete structure containing 1.0 kg per 1 m ^{3 of chloride.} The chloride ion sensor that measures the chloride ion concentration was evaluated by setting ○ in the case and × in other cases.

1 Substrate 2 Conductive layer 3 Conductive hot-melt adhesive layer 4 Adhesive 5 Encapsulating layer 6 Insulating hot-melt adhesive layer 7 Wiring 8 Reinforcing bar 9 Concrete 10 Potential difference detector 11 Impedance measuring instrument 20 Conductive laminate 30 Adhesive structure body

Claims (13)

A conductive laminate having at least a conductive layer and a conductive hot melt adhesive layer in contact with the conductive layer on a substrate, and the volume resistivity of the conductive hot melt adhesive layer is 1 × 10 ^-1 Ωcm or more 1 × 10 ³ to less than [Omega] cm, electroconductive laminate, wherein the volume resistivity of the conductive layer is less than ^{1 × 10 0 Ωcm 1 × 10} -5 Ωcm or more. The conductive laminate according to claim 1, wherein the elastic modulus of the conductive hot-melt adhesive layer is less than 5.0 MPa at 25 ° C. The conductive laminate according to claim 1 or 2, wherein the conductive layer and / or the conductive hot melt adhesive layer is patterned. 3. The conductivity according to claim 3, further comprising a patterned insulating hot melt adhesive layer around the patterned conductive layer and / or the patterned conductive hot melt adhesive layer. Laminated body. The conductive laminate according to any one of claims 1 to 4, wherein the conductive layer and the conductive hot melt adhesive layer contain a resin and a conductive filler, respectively. The conductive filler comprises at least one selected from the group consisting of graphite, carbon black, carbon nanotubes, graphene, graphene oxide, silver, copper, tin, zinc, zinc oxide, nickel, manganese, and ITO. The conductive laminate according to claim 5. The conductive laminate according to claim 6, wherein the conductive filler contains at least one selected from the group consisting of graphite, carbon black, carbon nanotubes, graphene, and graphene oxide. The conductivity according to any one of claims 5 to 7, wherein the resin in the conductive hot melt adhesive layer contains a styrene-based thermoplastic resin, and the resin in the conductive layer contains a phenoxy-based thermoplastic resin. Sex laminate. The conductive laminate according to any one of claims 1 to 8, wherein the conductive hot-melt adhesive layer and / or the insulating hot-melt adhesive layer has adhesiveness. An adhesive structure characterized in that the conductive laminated body and the adherend according to any one of claims 1 to 9 are laminated. It is a natural potential sensor that can measure the deterioration of the reinforcing bars existing inside the concrete through the signal obtained from the conductive laminate.
The natural potential measurement sensor according to claim 1 to 9, wherein the conductive laminate is the conductive laminate. It is a chloride ion sensor that can measure the chloride ion concentration inside concrete through a signal obtained from a conductive laminate.
A chloride ion sensor, wherein the conductive laminate is the conductive laminate according to claim 1. A printing step of printing a conductive layer on a substrate, which is a method for producing a conductive laminate having at least a conductive layer and a conductive hot melt adhesive layer adjacent to the conductive layer on the substrate. And a printing step of printing the conductive hot melt adhesive layer, the volume resistivity of the conductive hot melt adhesive layer is 1 × 10 ^-1 Ωcm or more and ^{less than 1 × 10 3} Ωcm, and the conductive layer method for producing a conductive laminate, wherein the volume resistivity is less than ^{1 × 10 0 Ωcm 1 × 10} -5 Ωcm or more.

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