Leak detection sensor and leak detection system

Abstract

We provide a liquid leak detection sensor and liquid leak detection system that can reliably detect leaks. [Solution] The liquid leak detection sensor 10 comprises a sheet-like substrate 1, a first wiring 2 provided on the first main surface 1a of the substrate 1, and a protective layer 3 covering the first wiring 2. The electrical resistance of the first wiring 2 increases when it comes into contact with a liquid lipophilic substance. The protective layer 3 is more permeable to lipophilic substances than water.

Description

Technical Field

[0001] The present invention relates to a liquid leakage detection sensor and a liquid leakage detection system.

Background Art

[0002] Conventionally, sensors that detect oil leakage by utilizing the increase in the electrical resistance of wiring upon contact with oil have been used. For example, the sensor includes a base layer, a conductive line formed on a surface of the base layer, and a protective layer covering the surface of the base layer. In this sensor, when oil comes into contact with the conductive line through a sensing hole formed in the protective layer, the electrical resistance of the conductive line increases (see, for example, Patent Document 1).

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In the aforementioned sensor, when rainwater, dew condensation, or the like comes into contact with the conductive line, the electrical resistance of the conductive line may decrease. For this reason, there has been a possibility that detection of oil becomes unstable.

[0005] An object of one aspect of the present invention is to provide a liquid leakage detection sensor and a liquid leakage detection system capable of stable leakage detection.

Means for Solving the Problem

[0006] One aspect of the present invention is a liquid leakage detection sensor including: a sheet-shaped base material; a first wiring formed on a first main surface of the base material, the electrical resistance value of which increases when the first wiring comes into contact with a liquid lipophilic substance; and a protective layer covering the first wiring, wherein the protective layer allows lipophilic substances to permeate more easily than water.

[0007] The liquid leak detection sensor further has a second wiring that is electrically connected to the first wiring, and the protective layer is formed to cover substantially the entire area of ​​the first wiring, and at least a portion of the second wiring may be exposed from the protective layer.

[0008] The liquid leak detection sensor has a release layer in at least a portion of the area between the first wiring and the protective layer, and the release layer may have weaker adhesion to the first wiring than to the protective layer.

[0009] The liquid leak detection sensor has a conductive release layer in at least a portion of the region between the first wiring and the protective layer, and the release layer may have stronger adhesion to the first wiring than the protective layer.

[0010] The protective layer has an extended region formed in the width direction from the substrate in a plan view, and may further comprise an adhesive layer extending from the second main surface of the substrate opposite to the first main surface to the extended region.

[0011] The liquid leak detection sensor further comprises an adhesive layer provided between the substrate and the protective layer, which adheres the substrate and the protective layer, and the adhesive layer may be more permeable to lipophilic substances than to water.

[0012] The first wiring comprises a conductive material and a resin material, and the protective layer may contain a resin that permeates the lipophilic substance or a resin that swells upon contact with the lipophilic substance.

[0013] Preferably, the protective layer is designed to be penetrated in the thickness direction by protrusions.

[0014] Another aspect of the present invention is a liquid leak detection system comprising the liquid leak detection sensor and a non-contact type data transmitter / receiver electrically connected to the first wiring.

[0015] Preferably, the liquid leakage detection system further comprises a connector having a conductive projection that penetrates through the protective layer and is electrically connected to the first wiring.

Effects of the Invention

[0016] According to one aspect of the present invention, a liquid leakage detection sensor and a liquid leakage detection system capable of stable leakage detection can be provided.

Brief Description of Drawings

[0017] [Figure 1] It is a configuration diagram of the liquid leakage detection system according to the first embodiment. [Figure 2] It is a plan view of the liquid leakage detection sensor according to the first embodiment. [Figure 3] It is a cross-sectional view taken along line I-I of FIG. 2. [Figure 4] It is a cross-sectional view taken along line I-I of FIG. 2. [Figure 5] It is a plan view of the liquid leakage detection sensor according to the second embodiment. [Figure 6] It is a cross-sectional view taken along line II-II of FIG. 5. [Figure 7] It is a plan view of the liquid leakage detection sensor according to the third embodiment. [Figure 8] It is a cross-sectional view taken along line III-III of FIG. 7. [Figure 9] It is a plan view of the liquid leakage detection sensor according to the third embodiment. [Figure 10] It is a cross-sectional view taken along line IV-IV of FIG. 9. [Figure 11] It is a plan view of the liquid leakage detection sensor according to the fourth embodiment. [Figure 12] It is a cross-sectional view taken along line V-V of FIG. 11. [Figure 13] It is a plan view of the liquid leakage detection sensor according to the fourth embodiment. [Figure 14] It is a plan view of the liquid leakage detection sensor according to the fifth embodiment. [Figure 15] It is a cross-sectional view taken along line VI-VI of FIG. 14. [Figure 16]This is a schematic diagram showing the usage configuration of the liquid leak detection sensor according to the fifth embodiment. [Figure 17] This is a plan view of the liquid leak detection sensor according to the sixth embodiment. [Figure 18] This is a cross-sectional view taken along line VII-VII in Figure 17. [Figure 19] This is a schematic diagram showing the usage configuration of the liquid leak detection sensor according to the sixth embodiment. [Figure 20] This is a cross-sectional view of the liquid leak detection sensor according to the seventh embodiment. [Figure 21] This is a diagram showing the configuration of the liquid leak detection system according to the second embodiment. [Figure 22] This is a diagram showing the configuration of the connector for the liquid leak detection system according to the second embodiment. [Figure 23] This is a diagram showing the configuration of the connector for the liquid leak detection system according to the second embodiment. [Figure 24] This is a cross-sectional view of the liquid leak detection sensor according to the eighth embodiment. [Modes for carrying out the invention]

[0018] [Liquid Leak Detection System] (First Embodiment) Figure 1 is a configuration diagram of the liquid leak detection system 100 according to the first embodiment. Figure 2 is a plan view of the liquid leak detection sensor 10 according to the first embodiment. Figures 3 and 4 are cross-sectional views of the liquid leak detection sensor 10 perpendicular to the longitudinal direction. Figures 3 and 4 are cross-sectional views II of Figure 2.

[0019] As shown in Figure 1, the liquid leak detection system 100 comprises a liquid leak detection sensor 10, a non-contact type data transmitter / receiver 20, and connecting wires 31, 32, and 33. Note that the protective layer 3 is not shown in Figure 1.

[0020] The contactless data transmitter / receiver 20 can perform short-range wireless communication with the reader / writer 50. The contactless data transmitter / receiver 20 comprises an IC chip (not shown), an antenna 11 electrically connected to the IC chip, and wiring 12 and 13 electrically connected to the IC chip. The IC chip allows for contactless writing and reading of information via the antenna 11.

[0021] One end of connecting wires 31 and 32 is electrically connected to wires 12 and 13, respectively. The other ends of connecting wires 31 and 32 are electrically connected to one end of the two first wires 2 at one end of the liquid leak detection sensor 10. Connecting wire 33 electrically connects the other ends of the two first wires 2 at the other end of the liquid leak detection sensor 10. Connecting wires 31, 32, 33 and the first wires 2 form a loop circuit. This circuit extends from connecting wire 31 through one first wire 2, connecting wire 33, and the other first wire 2 to connecting wire 32.

[0022] The non-contact data transmitter / receiver 20 obtains the detection result of the electrical resistance value in the first wiring 2 by energizing the connecting wires 31, 32, 33 and the first wiring 2. The electrical resistance value can be detected, for example, by an electrical resistance meter built into the IC chip. The non-contact data transmitter / receiver 20 can transmit information regarding the detection result of the electrical resistance value to the reader / writer 50.

[0023] [Liquid Leak Detection Sensor] (First Embodiment) As shown in Figures 2 and 3, the liquid leak detection sensor 10 comprises a base material 1, two first wirings 2, and a protective layer 3.

[0024] The base material 1 is formed in a sheet shape. The base material 1 is, for example, flexible. The base material 1 is composed of an insulating material. As the base material 1, resin base materials, paper base materials, etc., can be used. Examples of resin base materials include base materials made of polycarbonate (PC); base materials made of polyester resins such as polyethylene terephthalate (PET); base materials made of polyolefin resins such as polypropylene (PP) and polyethylene (PE); base materials made of polyfluoroethylene resins such as polyvinyl fluoride; base materials made of polyamide resins such as nylon 6; base materials made of vinyl polymers such as polyvinyl chloride (PVC); base materials made of acrylic resins such as polymethyl methacrylate; base materials made of polystyrene; base materials made of polyarylate; and base materials made of polyimide.

[0025] The base material 1 is formed in the shape of a tape (strip). One side of the base material 1 is the first main surface 1a. The other side of the base material 1 (the side opposite to the first main surface 1a) is the second main surface 1b (see Figure 3). The thickness of the base material 1 can be, for example, 100 μm to 500 μm.

[0026] In the following explanation, the XYZ Cartesian coordinate system may be used. As shown in Figure 2, the X direction is the length direction of the first principal surface 1a. The Y direction is the width direction of the first principal surface 1a. The Y direction is perpendicular to the X direction within the plane along the first principal surface 1a. The Z direction is perpendicular to both the X and Y directions. Viewing from the Z direction is called a plan view.

[0027] In Figure 2, the upward direction is one direction in the Y direction (+Y direction). The downward direction in Figure 2 is the opposite direction to the +Y direction (-Y direction). In Figure 2, the direction towards the viewer relative to the plane of the paper is one direction in the Z direction (+Z direction). In Figure 2, the direction away from the plane of the paper is the opposite direction to the +Z direction (-Z direction).

[0028] The two first wirings 2 are formed on the first main surface 1a of the base material 1. The first wirings 2 are formed along the length direction (X direction) of the base material 1. The first wirings 2 are formed along the entire length of the base material 1. The two first wirings 2 are spaced apart from each other in the width direction (Y direction) of the base material 1. The two first wirings 2 are formed in parallel. The two first wirings 2 are parallel to each other. The two first wirings 2 are also called first wirings 2A and 2B, respectively.

[0029] The first wiring 2 is formed at a position away from the widthwise end (side end 1c) of the first main surface 1a. More specifically, of the two first wirings 2, first wiring 2A is located inward in the widthwise direction (-Y direction) from one side end 1c (side end 1c in the +Y direction in Figure 2). Of the two first wirings 2, first wiring 2B is located inward in the widthwise direction (+Y direction) from the other side end 1c (side end 1c in the -Y direction in Figure 2). Inward in the widthwise direction is the direction in which one side end 1c and the other side end 1c move closer together.

[0030] The first wiring 2 is formed from a first wiring composition that includes, for example, a swellable material (resin material) and a conductive material. The swellable material has the property of absorbing lipophilic substances and swelling. The swellable material has a high affinity for lipophilic substances.

[0031] Examples of swellable materials include resins such as acrylic polymers, polystyrene, vinyl acetate polymers (ethylene vinyl acetate copolymers, etc.), vinylidene chloride polymers, vinyl chloride polymers, styrene-butadiene copolymers, polybutadiene, acrylonitrile-butadiene polymers, polychloroprene, polybutylene, polyisobutylene, isoprene-isobutylene copolymers, and terpene phenols. These swellable materials may be used individually or in combination of two or more.

[0032] The conductive material imparts conductivity to the first wiring 2. The conductive material is, for example, a conductor such as conductive particles or conductive fibers. The conductive material is dispersed in a swellable material. The conductive material is composed of carbon-based materials, metallic materials, etc.

[0033] Examples of carbon-based materials include carbon black, graphite, carbon nanotubes, fullerenes, and carbon fibers. One of these carbon-based materials may be used alone, or two or more may be used in combination. The conductor formed from the carbon-based material may be in particulate, fine powder, or fibrous form. Using a carbon-based material can suppress the degradation of the first wiring 2. Therefore, the durability of the first wiring 2 can be improved.

[0034] Examples of metallic materials include metals such as gold, silver, copper, and aluminum; alloys containing the aforementioned metals; and metal oxides containing the aforementioned metals. The metallic material may consist of one of these metals alone or two or more in combination. The conductor formed from the metallic material may be particulate, fine powder, or fibrous. The conductor formed from the metallic material may also be a composite of multiple metals. For example, it may be a structure in which a coating of a second metal is formed on the surface of particles made of a first metal.

[0035] The content of conductive material in the first wiring 2 is, for example, 5% to 90% by mass. The blending ratio (swellable material:conductive material) (by mass) of swellable material and conductive material in the first wiring 2 is, for example, 3:97 to 50:50. The first wiring 2 may optionally contain fillers, dispersants, plasticizers, antioxidants, surfactants, softeners, anti-aging agents, stabilizers, leveling agents, defoamers, hydrolysis inhibitors, leavening agents, thickeners, colorants, etc.

[0036] The electrical resistance of the first wiring 2 changes when it comes into contact with a lipophilic substance. More specifically, when a lipophilic substance comes into contact with the first wiring 2, the lipophilic substance is absorbed by the first wiring 2. As a result, the swelling material swells, and the volume of the first wiring 2 increases. When the volume of the first wiring 2 increases, the distance between the conductive materials increases, and therefore the electrical resistance of the first wiring 2 increases.

[0037] As shown in Figure 2, the protective layer 3 is formed on the first main surface 1a of the substrate 1. In a plan view, the protective layer 3 covers the first wiring 2 along its length. The protective layer 3 covers both first wirings 2 together. The protective layer 3 is formed of, for example, an insulating resin material.

[0038] The resin material used in protective layer 3 may be the same as the swellable material (resin material) used in the first wiring 2. Specifically, examples of resins include acrylic polymers, polystyrene, vinyl acetate polymers (such as ethylene vinyl acetate copolymers), vinylidene chloride polymers, vinyl chloride polymers, styrene-butadiene copolymers, polybutadiene, acrylonitrile-butadiene polymers, polychloroprene, polybutylene, polyisobutylene, isoprene-isobutylene copolymers, and terpene phenols. The resin material used in protective layer 3 may also be polyolefin resins such as polypropylene (PP) and polyethylene (PE), polystyrene, vinyl resins, polyester, polyamide, etc. One of these resin materials may be used alone, or two or more may be used in combination.

[0039] The protective layer 3 may, if necessary, contain fillers, dispersants, plasticizers, antioxidants, surfactants, softeners, anti-aging agents, stabilizers, leveling agents, defoamers, hydrolysis inhibitors, leavening agents, thickeners, colorants, etc.

[0040] The protective layer 3 covers the first wiring 2, except for the area including the end of the first wiring 2 (end area 2C). The protective layer 3 covers the entire area of ​​the first wiring 2 excluding the end area 2C (main part 102). The part of the first wiring 2 that has the function of detecting liquid leakage is included in the main part 102. In other words, the part of the first wiring 2 that has the function of detecting liquid leakage is covered by the protective layer 3.

[0041] As shown in Figures 3 and 4, the protective layer 3 is more permeable to lipophilic substances O (e.g., polyalphaolefins) than to water W. For example, as shown in Figure 3, lipophilic substances O easily penetrate the protective layer 3. Lipophilic substances O easily permeate the protective layer 3 from one surface 3a (outer surface 3a) to the other surface 3b (inner surface 3b). As shown in Figure 4, water W does not easily penetrate the protective layer 3. Water W is relatively difficult to permeate the protective layer 3 from the outer surface 3a to the inner surface 3b. The outer surface 3a is the +Z side surface of the protective layer 3. The inner surface 3b is the -Z side surface of the protective layer 3.

[0042] In protective layer 3, which is "more permeable to lipophilic substances than water," for example, when water is brought into contact with one surface of protective layer 3, the amount of lipophilic substance that reaches the other surface when it is brought into contact with one surface of protective layer 3 is greater than the amount of water that reaches the other surface when water is brought into contact with one surface of protective layer 3. Lipophilic substances that come into contact with one surface of protective layer 3 reach the other surface faster than water.

[0043] The protective layer 3 may be transparent enough to allow the first wiring 2 to be visible. The protective layer 3 may also be opaque.

[0044] The resin material used in the protective layer 3 may be different from the swellable material used in the first wiring 2. The protective layer 3 may contain a resin that allows lipophilic substances to permeate, or a resin that swells upon contact with a lipophilic substance. The resin that allows lipophilic substances to permeate is a resin that has the property of permeating lipophilic substances more easily than water, and examples of the aforementioned acrylic polymers, polystyrene, vinyl acetate polymers, etc., can be used. The resin that swells upon contact with a lipophilic substance is the aforementioned swellable material that has the property of permeating lipophilic substances more easily than water. Examples of resins that swell upon contact with a lipophilic substance include the aforementioned acrylic polymers, polystyrene, vinyl acetate polymers, etc.

[0045] [Manufacturing method for liquid leak detection sensors] A method for manufacturing a liquid leak detection sensor 10 will be described.

[0046] (Step 1: Formation of the first wiring) As shown in Figure 2, a first wiring composition containing a swellable material and a conductive material is used to form a first wiring 2 on the first main surface 1a of the substrate 1 by a known printing method or the like. Examples of printing methods include screen printing. The first wiring 2 may also be formed by a known coating method. After applying the first wiring composition to the first main surface 1a, it may be air-dried or dried using a drying oven.

[0047] (Step 2: Formation of protective layer) Using a protective layer composition containing the material for the protective layer 3 (e.g., a resin material), the protective layer 3 is formed on the first main surface 1a of the substrate 1 so as to cover the first wiring 2 by a known printing method or the like. Examples of printing methods include screen printing. The protective layer 3 may also be formed by a known coating method. After being applied to the first main surface 1a, the protective layer composition may be air-dried or dried using a drying oven.

[0048] [How to use the leak detection sensor and leak detection system] An example of how to use the liquid leak detection sensor 10 and the liquid leak detection system 100 (see Figure 1) will be described.

[0049] As shown in Figure 1, the piping 110 is made of metal, resin, etc. A liquid lipophilic substance flows through the piping 110. A lipophilic substance is a substance that has a high affinity for oil, nonpolar solvents, etc. Examples of lipophilic substances include mineral oils, synthetic oils, animal oils, and vegetable oils. Mineral oils include petroleum oils. Synthetic oils include hydrocarbon oils (such as polyalphaolefin (PAO)), silicone oils, and fluorinated oils. Hydrocarbon oils may also be petroleum oils. Examples of petroleum oils include crude oil, heavy oil, gasoline, light oil, kerosene, and naphtha. Nonpolar or low-polarity organic materials can also be considered lipophilic substances. Examples of nonpolar or low-polarity organic materials include hydrocarbons such as diethyl ether, n-hexane, and n-pentane; halides such as carbon tetrachloride and chloroform; esters such as ethyl acetate; and aromatic compounds such as benzene and toluene. Organic solvents that are soluble in water may have properties equivalent to lipophilic substances. Examples of organic solvents that are soluble in water include ethanol, isopropanol (IPA), and acetone. Organic solvents that are soluble in water may be detected by the leak detection sensor 10.

[0050] The leak detection sensor 10 can be installed at the bottom of the outer surface of the piping 110. The leak detection sensor 10 may be installed with the first main surface 1a of the base material 1 facing upwards. The leak detection sensor 10 may be installed with the first main surface 1a of the base material 1 facing downwards.

[0051] The non-contact data transmitter / receiver 20 can energize the first wiring 2 of the liquid leak detection sensor 10.

[0052] Assume that an oil-lipophilic substance O leaked from pipe 110 and came into contact with the leak detection sensor 10. As shown in Figure 3, when the lipophilic substance O comes into contact with the leak detection sensor 10, the lipophilic substance O comes into contact with the outer surface 3a of the protective layer 3 and penetrates the protective layer 3. The lipophilic substance O permeates through the protective layer 3 and comes into contact with the first wiring 2. The lipophilic substance O is absorbed by the first wiring 2. The swelling material contained in the first wiring 2 swells, and the volume of the first wiring 2 increases. As the volume of the first wiring 2 increases, the distance between the conductive materials increases, and the electrical resistance value of the first wiring 2 increases. The leak detection system 100 can determine that the lipophilic substance O has come into contact with the leak detection sensor 10 if the detected value of the electrical resistance value exceeds a predetermined set value. Therefore, the leak detection system 100 can detect that the lipophilic substance O has leaked from the piping 110.

[0053] The non-contact data transmitter / receiver 20 can transmit information regarding the detection result of the electrical resistance value of the first wiring 2 to the reader / writer 50.

[0054] As shown in Figure 4, when water W, such as rainwater or condensation, comes into contact with the liquid leak detection sensor 10, the water W does not easily penetrate the protective layer 3, so contact between the water W and the first wiring 2 is unlikely to occur. Therefore, the electrical resistance value of the first wiring 2 is unlikely to change.

[0055] [Effects of the liquid leak detection sensor and liquid leak detection system of the embodiment] The liquid leak detection sensor 10 of this embodiment has a protective layer 3 that is more permeable to lipophilic substances than water. Therefore, when water W, such as rainwater or condensation, comes into contact with the liquid leak detection sensor 10, the water W is less likely to come into contact with the first wiring 2. As a result, changes in the electrical resistance value of the first wiring 2 due to contact with water can be suppressed. Thus, stable detection of leaks of lipophilic substances is possible even when rainwater, condensation, etc., occur.

[0056] The liquid leak detection sensor 10 is equipped with a protective layer 3 that covers the first wiring 2, thereby increasing the durability of the first wiring 2.

[0057] The liquid leak detection sensor 10 can use the same resin material for the protective layer 3 as the resin material used for the first wiring 2. With this configuration, the protective layer 3 can be given the property of absorbing lipophilic substances. As a result, lipophilic substances can easily permeate the protective layer 3. Therefore, leaks of lipophilic substances can be detected with high sensitivity.

[0058] As shown in Figure 1, the liquid leak detection system 100 is equipped with a liquid leak detection sensor 10, enabling stable detection of leaks of lipophilic substances.

[0059] Since the liquid leak detection system 100 is equipped with a non-contact type data receiver / transmitter 20, a power supply is not required to energize the liquid leak detection sensor 10. Therefore, the device structure can be simplified and costs can be reduced.

[0060] [Liquid Leak Detection Sensor] (Second Embodiment) Figure 5 is a plan view of the liquid leak detection sensor 210 according to the second embodiment. Figure 6 is a cross-sectional view of the liquid leak detection sensor 210 perpendicular to the longitudinal direction. Figure 6 is a cross-sectional view taken along line II-II of Figure 5. Common components with other embodiments are denoted by the same reference numerals and their description is omitted.

[0061] As shown in Figures 5 and 6, the liquid leak detection sensor 210 comprises a base material 1, two first wirings 2, a protective layer 3, and a plurality of second wirings 4. The liquid leak detection sensor 210 differs from the liquid leak detection sensor 10 shown in Figure 2 in that it has second wirings 4.

[0062] The protective layer 3 covers the entire area of ​​the main portion 102 of the first wiring 2 (excluding the end region) in a plan view. Therefore, the protective layer 3 covers almost the entire area of ​​the first wiring 2.

[0063] A portion of the second wiring 4 is formed to overlap the outer surface 2a of the first wiring 2 in a plan view. The second wiring 4 is electrically connected to the first wiring 2 in the region where it overlaps with the first wiring 2. The second wiring 4 extends outward in the width direction from the first wiring 2. The rest of the second wiring 4 is formed on the first main surface 1a of the base material 1, located outside the width direction of the first wiring 2.

[0064] The region including the outer end 4a of the second wiring 4 is formed outward from the side edge of the protective layer 3. Therefore, this region is exposed. In this embodiment, only a portion of the second wiring 4 is exposed, but the entire second wiring 4 may be exposed. That is, at least a portion of the second wiring 4 needs to be exposed. Multiple second wirings 4 are formed at intervals along the length of the first wiring 2.

[0065] The second wiring 4 includes a conductive material. The conductive material may be a carbon-based material or a metallic material. Examples of carbon-based materials include carbon black, graphite, carbon nanotubes, fullerenes, and carbon fibers. Examples of metallic materials include metals such as gold, silver, copper, and aluminum; alloys containing the aforementioned metals; and metal oxides containing the aforementioned metals.

[0066] In the liquid leak detection sensor 210 of this embodiment, similar to the liquid leak detection sensor 10 of the first embodiment, it is possible to suppress changes in the electrical resistance value of the first wiring 2 due to contact with water. Therefore, stable detection of leaks of lipophilic substances is possible.

[0067] The liquid leak detection sensor 210 has a second wiring 4. Since at least a portion of the second wiring 4 is exposed, it can be electrically connected to an external measuring instrument and the first wiring 2 via the second wiring 4.

[0068] If the second wiring 4 is made of a carbon-based material, it is less prone to degradation. Therefore, the durability of the liquid leak detection sensor 210 can be increased.

[0069] [Liquid Leak Detection Sensor] (Third Embodiment) Figure 7 is a plan view of the liquid leak detection sensor 310 according to the third embodiment. Figure 8 is a cross-sectional view of the liquid leak detection sensor 310 perpendicular to the longitudinal direction. Figure 8 is a cross-sectional view taken along line III-III in Figure 7. Common components with other embodiments are denoted by the same reference numerals and their description is omitted.

[0070] As shown in Figures 7 and 8, the liquid leak detection sensor 310 comprises a base material 1, two first wirings 2, a protective layer 3, and a plurality of release layers 5. The liquid leak detection sensor 310 differs from the liquid leak detection sensor 10 shown in Figure 2 in that it has release layers 5.

[0071] The protective layer 3 covers the entire area of ​​the main portion 102 of the first wiring 2 (excluding the end region) in a plan view. Therefore, the protective layer 3 covers almost the entire area of ​​the first wiring 2.

[0072] The release layer 5 is insulating. The release layer 5 is formed of an insulating material. The release layer 5 can be formed by release varnish, release tape, etc. The release layer 5 is formed in at least a portion of the area between the first wiring 2 and the protective layer 3. The release layer 5 is formed along the width direction of the substrate 1, spanning two first wirings 2. The release layer 5 has weaker adhesion to the first wirings 2 than to the protective layer 3. Multiple release layers 5 are formed at intervals along the length direction of the first wirings 2.

[0073] Figure 9 is a plan view of the liquid leak detection sensor 310. Figure 10 is a cross-sectional view of the liquid leak detection sensor 310 perpendicular to its length. Figure 10 is a cross-sectional view taken along line IV-IV of Figure 9. As shown in Figures 9 and 10, by peeling off at least one release layer 5 and the protective layer 3 that overlaps it from the substrate 1, the first wiring 2 at the peeled area can be exposed.

[0074] In the liquid leak detection sensor 310 of this embodiment, similar to the liquid leak detection sensor 10 of the first embodiment, it is possible to suppress changes in the electrical resistance value of the first wiring 2 due to contact with water. Therefore, stable detection of leaks of lipophilic substances is possible.

[0075] Since the liquid leak detection sensor 310 has a release layer 5, the first wiring 2 can be exposed by peeling off the release layer 5 and the protective layer 3 that overlaps it from the substrate 1. Therefore, an external measuring device can be electrically connected to the first wiring 2. The first wiring 2 of the liquid leak detection sensor 310 will not be exposed unless the peeling layer 5 and the protective layer 3 overlapping it are peeled off. Therefore, unintended short circuits of the first wiring 2 due to contact with water can be avoided.

[0076] [Liquid Leak Detection Sensor] (Fourth Embodiment) Figure 11 is a plan view of the liquid leak detection sensor 410 according to the fourth embodiment. Figure 12 is a cross-sectional view of the liquid leak detection sensor 410 perpendicular to the longitudinal direction. Figure 12 is a cross-sectional view of VV in Figure 11. Common components with other embodiments are denoted by the same reference numerals and their description is omitted.

[0077] As shown in Figures 11 and 12, the liquid leak detection sensor 410 comprises a base material 1, two first wirings 2, two protective layers 403, and a plurality of release layers 405. The liquid leak detection sensor 410 differs from the liquid leak detection sensor 10 shown in Figure 2 in that a protective layer 403 is formed in place of a protective layer 3, and that it has release layers 405.

[0078] The protective layer 403 is formed on the first main surface 1a of the base material 1. In a plan view, the protective layer 403 covers the first wiring 2 along its length. The two protective layers 403 each cover two first wirings 2. The two protective layers 403 are formed spaced apart in the width direction of the base material 1. In a plan view, the protective layer 403 covers the entire area of ​​the main part 102 (excluding the end area) of the first wiring 2. Therefore, the protective layer 403 covers almost the entire area of ​​the first wiring 2.

[0079] The protective layer 403 has the property of being more permeable to lipophilic substances than to water. Lipophilic substances easily permeate the protective layer 403 from one surface 403a to the other surface 403b.

[0080] The release layer 405 is conductive. The release layer 405 contains a conductive material. The conductive material is a carbon-based material, a metallic material, etc. The release layer 405 is formed in at least a portion of the region between the first wiring 2 and the protective layer 403. The release layer 405 is formed on each of the two first wirings 2. The release layer 405 overlapping one first wiring 2 and the release layer 405 overlapping the other first wiring 2 are formed with a gap in the width direction of the substrate 1. Therefore, the release layer 405 is formed so as not to straddle the two first wirings 2.

[0081] The release layer 405 has stronger adhesion to the first wiring 2 than to the protective layer 403. Multiple release layers 405 are formed at intervals along the length of the first wiring 2.

[0082] As shown in Figure 13, the liquid leak detection sensor 410 can peel off the portion of the protective layer 403 that overlaps with the release layer 405 by removing the adhesive tape attached to a predetermined area of ​​the protective layer 403. This allows the release layer 405 at the peeled location to be exposed.

[0083] In the liquid leak detection sensor 410 of this embodiment, similar to the liquid leak detection sensor 10 of the first embodiment, it is possible to suppress changes in the electrical resistance value of the first wiring 2 due to contact with water. Therefore, stable detection of leaks of lipophilic substances is possible.

[0084] Since the liquid leak detection sensor 410 has a peel-off layer 405, the peel-off layer 405 can be exposed by peeling off the protective layer 403 in the portion overlapping the peel-off layer 405. Therefore, an external measuring instrument can be electrically connected to the first wiring 2 via the peel-off layer 405. Since the first wiring 2 is not exposed in the liquid leak detection sensor 410, deterioration of the first wiring 2 can be suppressed.

[0085] [Liquid Leak Detection Sensor] (Fifth Embodiment) Figure 14 is a plan view of the leak detection sensor 510 according to the fifth embodiment. Figure 15 is a cross-sectional view of the leak detection sensor 510 perpendicular to the longitudinal direction. Figure 15 is a cross-sectional view taken along line VI-VI in Figure 14. Figure 16 is a schematic diagram showing how the leak detection sensor 510 is used. Components common to other embodiments are denoted by the same reference numerals and their description is omitted.

[0086] As shown in Figures 14 and 15, the liquid leak detection sensor 510 comprises a base material 1, two first wirings 2, a protective layer 503, and an adhesive layer 6. The liquid leak detection sensor 510 differs from the liquid leak detection sensor 10 shown in Figure 2 in that it has a protective layer 503 instead of a protective layer 3, and has an adhesive layer 6.

[0087] The protective layer 503 is formed of a fiber aggregate (for example, fibers aggregated with internal voids). The fiber aggregate may be, for example, a nonwoven fabric or a woven fabric. The fibers are formed of, for example, a resin. As the resin constituting the fibers, a lipophilic resin is preferred. Examples of lipophilic resins include polyolefins such as polypropylene, polyethylene, polybutene-1, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer; polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene succinate; polyamides such as nylon 6 and nylon 66; acrylics; aromatic vinyls; polycarbonates; polyvinyl chlorides; and polyurethanes. One of these resins may be used alone, or two or more may be used in combination.

[0088] The protective layer 503 may use fibers made of a hydrophilic material. Examples of hydrophilic materials include vinyl alcohol-based, rayon-based, and cellulose-based materials. Cotton, recycled paper, and pulp may also be used as hydrophilic materials. The fibers made of the hydrophilic material may be treated to make the surface more lipophilic. One of these hydrophilic materials may be used alone, or two or more may be used in combination.

[0089] Suitable commercially available materials for use in protective layer 503 include Tuffnel oil blotting (polypropylene) (manufactured by M.A. Life Materials), oil taker (cotton) (manufactured by Ozu Sangyo), E-mat (recycled paper) (manufactured by Matsuoka Paper Industry), Hatosheet NWB (pulp) (manufactured by Oji Kinocloth), and Hardwipe (pulp fiber + polyester nonwoven fabric) (manufactured by Hashimoto Cloth).

[0090] The protective layer 503 has the property of being more permeable to lipophilic substances (e.g., hydrophobic substances) than to water. Lipophilic substances easily permeate the protective layer 503 from one surface 503a to the other surface 503b.

[0091] The protective layer 503 has an extended region 503A formed by extending in the width direction of the base material 1 in a plan view. Therefore, the protective layer 503 is wider than the base material 1. The adhesive layer 6 has an extended region 6A formed by extending in the width direction of the base material 1. The adhesive layer 6 is wider than the base material 1.

[0092] The adhesive layer 6 is formed to extend from the second main surface 1b of the substrate 1 to the extended region 503A. The extended region 6A overlaps with the extended region 503A of the protective layer 503. The extended region 6A is bonded to the extended region 503A. A release sheet (e.g., release paper) may be bonded to the adhesive layer 6.

[0093] The adhesive layer 6 can be formed using a known adhesive. Examples of adhesives that can constitute the adhesive layer 6 include acrylic adhesives, silicone adhesives, urethane adhesives, rubber adhesives, etc. One of these adhesives may be used, or two or more may be used. At least one of acrylic adhesives and silicone adhesives is preferred as the adhesive for the adhesive layer 6.

[0094] The adhesive forming the adhesive layer 6 includes, for example, an acid-free crosslinked resin. The acid-free crosslinked resin is a crosslinked polymer obtained by polymerizing monomers that do not contain acidic groups, and then crosslinking that acid-free polymer with a crosslinking agent. Acidic groups include, for example, carboxyl groups, sulfonic acid groups, and phosphate groups. The monomer contains functional groups (such as hydroxyl groups and amino groups) for carrying out the crosslinking reaction with the crosslinking agent.

[0095] An acid-free crosslinked resin may be, for example, a crosslinked polymer obtained by crosslinking a monomer that does not contain acidic groups and contains at least one of hydroxyl groups and amino groups with a crosslinking agent. However, the acid-free crosslinked resin may contain trace amounts of acid that are inevitably introduced during the manufacturing process of the adhesive layer.

[0096] As shown in Figure 16, the protective layer 503 can be removed from the substrate 1 by peeling it off the adhesive layer 6. This exposes the first wiring 2. Therefore, external measuring equipment can be electrically connected to the first wiring 2.

[0097] In the liquid leak detection sensor 510 of this embodiment, similar to the liquid leak detection sensor 10 of the first embodiment, it is possible to suppress changes in the electrical resistance value of the first wiring 2 due to contact with water. Therefore, stable detection of leaks of lipophilic substances is possible.

[0098] In the liquid leak detection sensor 510, excessive force is less likely to be applied to the first wiring 2 when removing the protective layer 503 from the substrate 1. Therefore, damage to the first wiring 2 can be avoided.

[0099] [Liquid Leak Detection Sensor] (Sixth Embodiment) Figure 17 is a plan view of the leak detection sensor 610 according to the sixth embodiment. Figure 18 is a cross-sectional view of the leak detection sensor 610 perpendicular to the longitudinal direction. Figure 18 is a cross-sectional view taken along line VII-VII of Figure 17. Figure 19 is a schematic diagram showing how the leak detection sensor 610 is used. Components common to other embodiments are denoted by the same reference numerals and their description is omitted.

[0100] As shown in Figures 17 and 18, the liquid leak detection sensor 610 comprises a base material 1, two first wirings 2, a protective layer 603, and an adhesive layer 606. The liquid leak detection sensor 610 differs from the liquid leak detection sensor 10 shown in Figure 2 in that it has a protective layer 603 instead of a protective layer 3, and has an adhesive layer 606.

[0101] The protective layer 603, like the protective layer 503 of the liquid leak detection sensor 510 shown in Figure 14, has the property of being more permeable to lipophilic substances than to water. Lipophilic substances easily permeate the protective layer 603 from one surface 603a to the other surface 603b. The protective layer 603 has the same width as the substrate 1.

[0102] The adhesive layer 606 is formed between the first main surface 1a of the substrate 1 and the protective layer 603. The adhesive layer 606 makes it difficult for the protective layer 603 to peel off from the substrate 1. The adhesive layer 606 covers the first wiring 2 and the first main surface 1a. The adhesive layer 606 has the property of being more permeable to lipophilic substances than to water. Lipophilic substances easily permeate the adhesive layer 606 from one surface 606a to the other surface 606b. The adhesive layer 606 includes, for example, a material similar to that of the protective layer 3 (Figure 1) and an adhesive.

[0103] The adhesive layer 606 can be formed using a known adhesive. Examples of adhesives that can be used to constitute the adhesive layer 606 include acrylic adhesives, silicone adhesives, urethane adhesives, rubber adhesives, and the like. The adhesive layer 606 has insulating properties.

[0104] The adhesive layer 606 includes, for example, an acid-free crosslinked resin. Using an acid-free crosslinked resin in the adhesive layer 606 can suppress oxidation of the first wiring 2. Using an acid-free crosslinked resin in the adhesive layer 606 can suppress oxidation of the first wiring 2 in, for example, high-temperature and high-humidity environments. In particular, using at least one of an acrylic adhesive and a silicone adhesive can enhance the effect of suppressing oxidation of the first wiring 2.

[0105] The thickness of the adhesive layer 606 can be, for example, 10 μm or more and 30 μm or less. If the thickness of the adhesive layer 606 is 10 μm or more, the protective layer 603 will be less likely to peel off from the substrate 1. If the thickness of the adhesive layer 606 is 30 μm or less, the lipophilic substance that has penetrated the adhesive layer 606 will reach the first wiring 2 in a short time, thereby increasing the sensitivity of leak detection.

[0106] As shown in Figure 19, the protective layer 603 and the adhesive layer 606 can be peeled off from the substrate 1. This exposes the first wiring 2. Therefore, external measuring equipment can be electrically connected to the first wiring 2.

[0107] In the liquid leak detection sensor 610 of this embodiment, similar to the liquid leak detection sensor 10 of the first embodiment, it is possible to suppress changes in the electrical resistance value of the first wiring 2 due to contact with water. Therefore, stable detection of leaks of lipophilic substances is possible.

[0108] In the liquid leak detection sensor 610, an adhesive layer 606 is interposed between the protective layer 603 and the base material 1, making it difficult for water to penetrate the gap between the protective layer 603 and the base material 1. Therefore, changes in the electrical resistance value of the first wiring 2 due to contact with water can be suppressed. In the liquid leak detection sensor 610, the adhesive layer 606 makes it difficult for air to come into contact with the first wiring 2, thus suppressing oxidation of the first wiring 2.

[0109] In the liquid leak detection sensor 610, the adhesive layer 606 is covered with a protective layer 603, which reduces the tackiness of the surface of the liquid leak detection sensor 610 and makes it easier to handle. The liquid leak detection sensor 610 is also made more durable by the presence of the protective layer 603.

[0110] [Liquid Leak Detection Sensor] (7th Embodiment) Figure 20 is a cross-sectional view of the liquid leak detection sensor 710 according to the seventh embodiment, perpendicular to the longitudinal direction. Common components with other embodiments are denoted by the same reference numerals and their description is omitted.

[0111] As shown in Figure 20, the liquid leak detection sensor 710 comprises a base material 1, two first wirings 2, a protective layer 703, and an adhesive layer 706.

[0112] The protective layer 703, like the protective layer 503 of the liquid leak detection sensor 510 shown in Figure 14, has the property of being more permeable to lipophilic substances than to water. Lipophilic substances easily permeate the protective layer 703 from one surface 703a to the other surface 703b. The protective layer 703 has the same width as the substrate 1.

[0113] It is desirable that the protective layer 703 allows protrusions (for example, the conductive protrusions 107 shown in Figure 23) to penetrate in the thickness direction. The protective layer 703 is formed of fibers (a collection of fibers) assembled with internal voids, similar to the protective layer 503 shown in Figure 14. The collection of fibers may be, for example, a nonwoven fabric or a woven fabric. The protective layer 703 may also have a mesh structure formed by the fibers.

[0114] The fibers are formed from, for example, a resin. A lipophilic resin is preferred as the resin constituting the fibers. If the protective layer 703 is formed from an aggregate of fibers (e.g., a nonwoven fabric), lipophilic substances can easily penetrate through the gaps between the fibers. If the protective layer 703 is formed from an aggregate of fibers (e.g., a nonwoven fabric), the conductive protrusions 107 (see Figure 23) can easily penetrate in the thickness direction.

[0115] The adhesive layer 706 is formed between the first main surface 1a of the substrate 1 and the protective layer 703. The adhesive layer 706 makes it difficult for the protective layer 703 to peel off from the substrate 1. The adhesive layer 706 covers the first wiring 2 and the first main surface 1a. The adhesive layer 706 has the property of being more permeable to lipophilic substances than to water. Lipophilic substances easily permeate the adhesive layer 706 from one surface 706a to the other surface 706b.

[0116] The adhesive layer 706 can be formed from a known adhesive. Examples of adhesives that can be used to constitute the adhesive layer 706 include acrylic adhesives, silicone adhesives, urethane adhesives, rubber adhesives, etc. The adhesive layer 706 includes, for example, an acid-free crosslinked resin. When an acid-free crosslinked resin is used in the adhesive layer 706, oxidation of the first wiring 2 can be suppressed, for example, in a high-temperature and high-humidity environment. It is desirable that the adhesive layer 706 allows protrusions (for example, conductive protrusions 107 shown in Figure 23) to penetrate in the thickness direction. The adhesive layer 706 has insulating properties.

[0117] In the liquid leak detection sensor 710 of this embodiment, similar to the liquid leak detection sensor 10 of the first embodiment, it is possible to suppress changes in the electrical resistance value of the first wiring 2 due to contact with water. Therefore, stable detection of leaks of lipophilic substances is possible.

[0118] In the liquid leak detection sensor 710, an adhesive layer 706 is interposed between the protective layer 703 and the base material 1, making it difficult for water to penetrate the gap between the protective layer 703 and the base material 1. Therefore, changes in the electrical resistance value of the first wiring 2 due to contact with water can be suppressed. In the liquid leak detection sensor 710, the adhesive layer 706 makes it difficult for air to come into contact with the first wiring 2, thus suppressing oxidation of the first wiring 2.

[0119] In the liquid leak detection sensor 710, the adhesive layer 706 is covered with a protective layer 703. Therefore, the tackiness of the surface of the liquid leak detection sensor 710 is reduced, making it easier to handle. The presence of the protective layer 703 also enhances the durability of the liquid leak detection sensor 710.

[0120] [Liquid Leak Detection System] (Second Embodiment) Figure 21 is a configuration diagram of the liquid leak detection system 200 according to the second embodiment. Figures 22 and 23 are configuration diagrams of the first connector 101. Figures 22 and 23 show a cross-section along the length of the liquid leak detection sensor 710. Components common to other embodiments are denoted by the same reference numerals and their description is omitted.

[0121] As shown in Figure 21, the liquid leak detection system 200 comprises a liquid leak detection sensor 710, a non-contact type data transmitter / receiver 20, connecting wires 31 and 32, a first connector 101, and a second connector 111. Note that the protective layer 703 is not shown in Figure 21.

[0122] As shown in Figure 22, the first connector 101 (connector) comprises a substrate 103, a base portion 104, a connecting support portion 105, a cover portion 106, and two conductive protrusions 107 (projections). Multiple wiring layers 108 are formed on the upper surface of the substrate 103. The base portion 104 is provided on the upper surface of the substrate 103.

[0123] The lid portion 106 is rotatably connected to the connecting support portion 105 via a hinge 109. The lid portion 106 rotates using the hinge 109 as a pivot point to open and close the upper surface of the base portion 104.

[0124] The conductive projection 107 protrudes upward from the upper surface of the base portion 104. The conductive projection 107 has a sharp-shaped tip. The conductive projection 107 has, for example, a conical shape. The conductive projection 107 is made of, for example, metal. The conductive projection 107 is electrically connected to the wiring layer 108. Two of the multiple wiring layers 108 are electrically connected to connecting wires 31 and 32, respectively.

[0125] As shown in Figure 21, the first connector 101 is provided at one end of the liquid leak detection sensor 710. As shown in Figure 23, one end of the leak detection sensor 710 is placed on the base 104 and the lid 106 is closed. The leak detection sensor 710 is positioned with the protective layer 703 facing the base 104.

[0126] When the lid 106 presses the liquid leak detection sensor 710 downwards, the conductive projection 107 penetrates the protective layer 703 and the adhesive layer 706 in the thickness direction and reaches the first wiring 2. The conductive projection 107 is electrically connected to the first wiring 2. As a result, the two first wirings 2 are electrically connected to the connecting wirings 31 and 32, respectively.

[0127] As shown in Figure 21, the second connector 111 (connector) is provided at the other end of the liquid leak detection sensor 710. The second connector 111 electrically connects the other ends of the two first wires 2.

[0128] The non-contact data transmitter / receiver 20 obtains the detection result of the electrical resistance value in the first wiring 2 by energizing the first wiring 2. The non-contact data transmitter / receiver 20 can transmit information regarding the detection result of the electrical resistance value to the reader / writer 50.

[0129] The liquid leak detection system 200 is equipped with a liquid leak detection sensor 710, enabling stable detection of leaks of lipophilic substances. The liquid leak detection system 200 uses a first connector 101. The first connector 101 has a conductive projection 107 that penetrates the protective layer 703 and electrically connects to the first wiring 2. Therefore, the connecting wirings 31 and 32 and the liquid leak detection sensor 710 can be connected with easy operation.

[0130] The protective layer 703 of the liquid leak detection sensor 710 is designed to be penetrated in the thickness direction by conductive protrusions 107 (projections). Therefore, the liquid leak detection sensor 710 and the connecting wires 31 and 32 can be easily connected using the first connector 101.

[0131] [Liquid Leak Detection Sensor] (8th Embodiment) Figure 24 is a cross-sectional view of the liquid leak detection sensor 810 according to the eighth embodiment, perpendicular to the longitudinal direction. Common components with other embodiments are denoted by the same reference numerals and their description is omitted.

[0132] As shown in Figure 24, the liquid leak detection sensor 810 comprises a base material 1, two first wirings 2, and a protective layer 803. The liquid leak detection sensor 810 differs from the liquid leak detection sensor 710 shown in Figure 20 in that there is no adhesive layer between the protective layer 803 and the base material 1.

[0133] The protective layer 803 covers the first wiring 2 and the first main surface 1a. The protective layer 803 has the property of being more permeable to lipophilic substances than to water. Lipophilic substances easily permeate the protective layer 803 from one surface 803a to the other surface 803b. The protective layer 803 has the same width as the substrate 1.

[0134] The protective layer 803 is formed, for example, from a collection of fibers (e.g., nonwoven fabric, woven fabric, etc.). The protective layer 803 is impregnated with an adhesive (e.g., acrylic adhesive, silicone adhesive, etc.). Therefore, the protective layer 803 also functions as an adhesive layer.

[0135] In the liquid leak detection sensor 810 of this embodiment, similar to the liquid leak detection sensor 10 of the first embodiment, it is possible to suppress changes in the electrical resistance value of the first wiring 2 due to contact with water. Therefore, stable detection of leaks of lipophilic substances is possible.

[0136] Because the liquid leak detection sensor 810 has a protective layer 803 impregnated with adhesive, water is less likely to penetrate the gap between the protective layer 803 and the substrate 1. Therefore, changes in the electrical resistance value of the first wiring 2 due to contact with water can be suppressed. Because the liquid leak detection sensor 810 has a protective layer 803 impregnated with adhesive, air is less likely to come into contact with the first wiring 2. In this way, the liquid leak detection sensor 810 provides the same effect of protecting the first wiring 2 as the liquid leak detection sensor 710 shown in Figure 20.

[0137] Since the liquid leak detection sensor 810 has a protective layer 803 impregnated with adhesive, it can be made thinner compared to the case where an adhesive layer is provided between the base material 1 and the protective layer.

[0138] Although embodiments of the present invention have been described above, the configurations and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications to the configurations are possible without departing from the spirit of the present invention.

[0139] In the above embodiment, the liquid leak detection sensor 10 has two first wires 2, but the number of first wires 2 is not limited to 2. The number of first wires 2 may be 1 or multiple (any number of 2 or more).

[0140] In the liquid leak detection sensor 10 shown in Figure 2, the protective layer 3 covers two first wirings 2, but the number of first wirings 2 covered by the protective layer 3 may be as small as one. In other words, the protective layer 3 only needs to be formed to cover at least one first wiring 2.

[0141] In the liquid leak detection sensor 10 shown in Figure 2, two first wirings 2 are formed on the first main surface 1a of the base material 1, but the first wirings 2 do not have to be formed on the same main surface of the base material 1. For example, one of the two first wirings 2 may be formed on the first main surface 1a of the base material 1, and the other on the second main surface 1b. In this case as well, the two first wirings 2 are formed in parallel. In this configuration, the protective layer may cover both the first wiring on the first main surface and the first wiring on the second main surface, or it may cover only one of the first wiring on the first main surface and the first wiring on the second main surface. [Explanation of Symbols]

[0142] 1...Substrate, 1a...First main surface, 1b...Second main surface, 2,2A,2B...First wiring, 3,403,503,603,703,803...Protective layer, 4...Second wiring, 5,405...Release layer, 6,606,706,806...Adhesive layer, 10,210,310,410,510,610,710,810...Liquid leak detection sensor, 20...Non-contact data receiver / transmitter, 100,200...Liquid leak detection system, 101...First connector (connector), 107...Conductive protrusion (projection), 503A...Extended area, O...Lipophilic substance, W...Water

Claims

1. A sheet-like substrate, A first wiring is formed on the first main surface of the substrate, and its electrical resistance increases when it comes into contact with a liquid lipophilic substance. A protective layer covering the first wiring is provided, The aforementioned protective layer is more permeable to lipophilic substances than to water. Liquid leak detection sensor.

2. The system further comprises a second wiring that is electrically connected to the first wiring, The protective layer is formed to cover substantially the entire area of ​​the first wiring, At least a portion of the second wiring is exposed from the protective layer. The liquid leak detection sensor according to claim 1.

3. The region between the first wiring and the protective layer has a release layer in at least a portion thereof. The release layer has weaker adhesion to the first wiring compared to its adhesion to the protective layer. The liquid leak detection sensor according to claim 1.

4. A conductive release layer is provided in at least a portion of the region between the first wiring and the protective layer. The release layer has stronger adhesion to the first wiring than the protective layer. The liquid leak detection sensor according to claim 1.

5. The protective layer has an extended region formed in the width direction extending from the substrate in a plan view, The substrate further comprises an adhesive layer extending from the second main surface opposite to the first main surface to the extended region. The liquid leak detection sensor according to claim 1.

6. The adhesive layer is provided between the substrate and the protective layer and adheres the substrate and the protective layer together. The aforementioned adhesive layer is more permeable to lipophilic substances than to water. The liquid leak detection sensor according to claim 1.

7. The first wiring comprises a conductive material and a resin material, The protective layer includes a resin that allows the lipophilic substance to pass through, or a resin that swells upon contact with the lipophilic substance. The liquid leak detection sensor according to claim 1.

8. The aforementioned protective layer is designed to be penetrated in the thickness direction by a projection. The liquid leak detection sensor according to claim 1.

9. A liquid leak detection sensor according to any one of claims 1 to 8, The system comprises a non-contact type data transmitter / receiver electrically connected to the first wiring, Liquid leak detection system.

10. The connector further comprises conductive protrusions that penetrate the protective layer and electrically connect to the first wiring. The liquid leak detection system according to claim 9.

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