Sensor element, odor measuring device

Abstract

To provide a sensor element for an odor measurement device, which offers improved sensitivity to low-concentration components in odor measurement, improved measurement accuracy through iterative measurements, and improved response.SOLUTION: A sensor element (31) is provided, comprising an odor substance receptive layer (315) containing a resin composition, metal wiring (313) in contact with the odor substance receptive layer (315), and an odor substance-permeable layer (317) covering the odor substance receptive layer (315) on a side opposite the side in contact with the metal wiring. The odor substance-permeable layer (317) has a composition having at least either of a structure represented by R1-SiO3 / 2 and a structure represented by R2-SiO1, where R1 represents a hydrocarbon group having 1 to 18 carbon atoms, inclusive.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an odor measuring device. [Background technology]

[0002] With the recent advances in information processing technology, if it were possible to somehow quantify the sense of smell, which is one of the five human senses that cannot be adequately measured mechanically, it is expected that this technology could be used in a wide range of industrial fields, including the medical, environmental, biogas utilization, safety, food, and marketing fields. Such olfactory technology could be used for a variety of purposes, for example, as follows: Medical field: Nursing care, assistance, preventive diagnosis and disease testing, etc. · Environmental field: Odor control in factories, etc. · Biogas utilization: Fermentation process management and wastewater treatment management, etc. Safety: Predictive detection of landslides and floods, deterioration detection of engine oil and machine operating oil, etc. Food industry: Detection of the maturity state of food ingredients such as plants (e.g. vegetables and grains) and meat, process management of fermented foods such as alcoholic beverages, plant cultivation management, and quality control during the production, storage, and distribution of food. Marketing field: Cosmetics, body odor countermeasures, scent environments, product scent production, etc.

[0003] The invention described in Patent Document 1 proposes a mechanism for detecting the adsorption of odor components onto the surface of a conductive polymer by replacing the semiconductor in a semiconductor gas sensor with a conductive polymer. Patent Document 1 reports that it is possible to detect odor components that are easily thermally decomposed and substances that do not undergo redox reactions on the surface of the sensor's detection part.

[0004] Furthermore, Patent Document 2 focuses on the property that the electrical resistance of a mixture of an organic polymer and a conductive material changes when exposed to an organic gas. Patent Document 2 describes that when multiple combinations of organic polymer / conductive material, each with a different organic polymer composition, are prepared from the above mixture and used as an electrical resistance array in a sensor, the electrical resistance changes differently when exposed to the same organic gas. Patent Document 2 reports that this can be used to identify odors by associating the pattern of electrical resistance change with the type of odor (= organic gas mixture).

[0005] Furthermore, Patent Document 3 reports that the response speed of the sensor can be improved by adding a plasticizer to the organic polymer. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-23508 [Patent Document 2] Special Publication No. 11-503231 [Patent Document 3] Patent Publication No. 2002-519633 Summary of the Invention [Problem to be solved by the invention]

[0007] In odor measurement devices equipped with chemiresistor-type odor sensors, the change in electrical conductivity of the odorant receiving layer, which is caused by a volume change due to the adsorption of odorants by the odorant receiving layer, is detected as an electrical signal to measure the odorant. In odor measurement devices equipped with chemiresistor-type odor sensors, a method of simply extending the measurement time can be used to improve measurement sensitivity for low concentrations of odorants. However, extending the measurement time per measurement reduces responsiveness to changes in odorant concentration. To maintain responsiveness to changes in odorant concentration, a method of shortening the measurement time per measurement can be used. However, adopting this method reduces measurement sensitivity for low concentrations of odorants. Thus, in conventional odor measurement devices equipped with chemiresistor-type odor sensors, it has been difficult to simultaneously improve sensitivity for measuring low concentrations of odorants and improve measurement accuracy and responsiveness to changes in odorant concentration in repeated measurements.

[0008] An object of one aspect of the present invention is to provide a sensor element or the like that achieves improved sensitivity to low concentration components in odor measurement, improved measurement accuracy in repeated measurements, and improved responsiveness. [Means for solving the problem]

[0009] One aspect of the present invention is an odorant receiving layer comprising a resin composition containing a resin (A) and a filler (B), a first metal wiring in contact with at least a portion of the odorant receiving layer, a second metal wiring spaced apart from the first metal wiring and in contact with at least a portion of the odorant receiving layer, and an odorant permeation layer covering at least a portion of the odorant receiving layer opposite the side in contact with the first metal wiring and the second metal wiring, wherein the odorant permeation layer is composed of R1-SiO 3 / 2 and a structure represented by R2-SiO1, wherein R1 is a hydrocarbon group having 1 to 18 carbon atoms, and an odor measuring device including a plurality of such sensor elements. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide a sensor element that achieves improved sensitivity to low concentration components in odor measurement, improved measurement accuracy by enabling repeated measurements in a short measurement time, and improved responsiveness. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of an odor sensor according to one embodiment of the present invention. [Figure 2] This is an SEM image of a cross section of a sensor element. [Figure 3] FIG. 2 is a top view showing an example of the configuration of a sensor element. [Figure 4] FIG. 4 is a cross-sectional view showing an example of the configuration of the sensor element shown in FIG. [Figure 5] 1 is a schematic diagram showing an example of the configuration of an odor measurement device according to one embodiment of the present invention. [Figure 6] FIG. 1 is a functional block diagram showing an example of the configuration of an odor measurement device. [Figure 7] 10 is a flowchart illustrating an example of a processing flow in which the estimation device generates an estimation model. [Figure 8] FIG. 1 is a functional block diagram showing an example of the configuration of an odor measurement device. [Figure 9] 10 is a flowchart showing an example of the flow of a process in which the estimation device estimates an odor substance. [Figure 10] FIG. 2 is a top view showing an example of the configuration of a sensor element of the present invention. [Figure 11] FIG. 2 is a top view showing an example of the configuration of a sensor element of the present invention. [Figure 12] 1 is a perspective view showing an example of the configuration of a sensor element of the present invention. [Figure 13] 10 is a graph for explaining an operation for determining Tz. DETAILED DESCRIPTION OF THE INVENTION

[0012] One embodiment of the present invention will be described below, but the present invention is not limited thereto. Furthermore, unless otherwise specified in this specification, the expression "A to B" representing a range of numerical values ​​means "A or more and B or less."

[0013] [1. Sensor element 31] The present inventors have conducted research to achieve the above object and have arrived at the present invention.

[0014] The sensor element 31 for an odor measuring device according to one embodiment of the present invention is a chemiresistor-type odor sensor. The sensor element 31 includes an odorant receiving layer 315 containing a resin composition, a first metal wiring 313A and a second metal wiring 313B each in contact with at least a portion of the odorant receiving layer 315, and an odorant permeable layer 317. The resin composition contains a resin (A) and a filler (B). The first metal wiring 313A is spaced apart from the second metal wiring 313B.

[0015] The odorant-permeable layer 317 covers at least a portion of the odorant receiving layer 315 on the side opposite to the side in contact with the first metal wiring 313A and the second metal wiring 313B. The odorant-permeable layer 317 does not contact the first metal wiring 313A and the second metal wiring 313B. The odorant-permeable layer 317 is made of R1-SiO 3 / 2 and a structure represented by R2-SiO1. Here, R1 and R2 are hydrocarbon groups with 1 to 18 carbon atoms bonded to a silicon atom (Si). For example, the odorant permeation layer 317 may be provided so as to completely cover the side of the odorant receiving layer 315 opposite to the side in contact with the first metal wiring 313A and the second metal wiring 313B. The odorant permeation layer 317 and the odorant receiving layer 315 are in contact on a surface different from the surface of the odorant receiving layer 315 that contacts the first metal wiring 313A and the second metal wiring 313B. The odorant permeation layer 317 is not in contact with the first metal wiring 313A or the second metal wiring 313B.

[0016] [2-1. Odor-permeable layer] The odorant-permeable layer 317 of the sensor element 31 is made of R1-SiO 3 / 2 and a structure represented by R2-SiO1. 3 / 2 When the odorant-permeable layer 317 contains both the structure represented by R2-SiO1 and the structure represented by R2-SiO1, the odorant-permeable layer 317 becomes soft and has good responsiveness. Also, when the odorant-permeable layer 317 does not contain the structure represented by R2-SiO1, the odorant-permeable layer 317 becomes hard, shortening the time required for odorant desorption and improving measurement speed. R1-SiO 3 / 2 The mixing ratio of R2-SiO1 and R1-SiO2 is, for example, 3 / 2The ratio of R2-SiO1 is 0.9:0.1 to 0.7:0.3. Here, R1 is a hydrocarbon group having 1 to 18 carbon atoms. In the present invention, a hydrocarbon group is a group consisting of carbon atoms and hydrogen atoms. From the viewpoint of solubility during slurry preparation, the carbon number of R1 is preferably 1 to 12, more preferably 1 to 10, even more preferably 1 to 8, and even more preferably 1 to 6. Here, R1 may contain one or more functional groups selected from aliphatic hydrocarbon groups and aromatic groups, and more preferably contains a methyl group and / or an aromatic group. This improves the adhesion between the odorant permeation layer and the odorant receiving layer, thereby providing the sensor element 31 with excellent repeat measurement accuracy. Therefore, the sensor element 31 having the odorant permeation layer 317 according to the present disclosure can achieve both high measurement accuracy and high responsiveness in repeated measurements. Here, responsiveness refers to the time it takes for a measurement to be performed using the same sensor element 31 after a previous measurement. The sensor element 31 according to the present disclosure is capable of performing multiple measurements in a shorter time. Examples of the aliphatic hydrocarbon group include "alkyl groups having 1 to 18 carbon atoms." The "alkyl groups having 1 to 18 carbon atoms" may be linear or branched. Examples of linear alkyl groups include methyl, ethyl, propyl, butyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups. Examples of branched alkyl groups include isopropyl, sec-butyl, tert-butyl, isobutyl, isopentyl, tert-pentyl, 2-hexyl, 3-hexyl, 2-heptyl, 3-heptyl, isoheptyl, tert-heptyl, isooctyl, tert-octyl, 2-ethylhexyl, and isononyl groups. Examples of aromatic groups having 6 to 18 carbon atoms include phenyl, indenyl, naphthyl, biphenylyl, fluorenyl, phenanthrenyl, and anthracenyl groups.R2 may contain one or more functional groups selected from the group consisting of a hydrogen atom, a methyl group, an alkyl group having from 1 to 12 carbon atoms, an amino group, a hydroxyl group, a carboxyl group, a fluoromethyl group, a polyester group, a polyether group, an amide group, and an aralkyl group having from 1 to 12 carbon atoms.

[0017] R2 preferably contains one or more functional groups selected from the group consisting of a carboxyl group, an amide group, an alkyl group, and a fluoromethyl group. In particular, R2 preferably contains one or more functional groups selected from the group consisting of a hydrogen atom, an amide group, a methyl group, an alkyl group having 1 to 12 carbon atoms, an aralkyl group having 1 to 12 carbon atoms, a carboxyl group, and a fluoromethyl group. When R2 contains the above-mentioned functional groups, the degree to which R2 inhibits the gas permeability characteristic of silicone is reduced. When the odorant-permeable layer 317 contains the above-mentioned R2, Tz, the time from the completion of one measurement until the next measurement can be performed, tends to be shortened. Therefore, when the odorant-permeable layer 317 contains the above-mentioned R2, a permeable layer with excellent properties can be achieved.

[0018] The odorant permeable layer 317 containing this composition can be a layer that has the function of selectively allowing odorants to reach the odorant receiving layer 315. The odorant permeable layer 317 can also function as a protective layer that reduces the rate at which the odorant receiving layer 315 deteriorates due to factors such as humidity in the measurement environment.

[0019] The odorant permeation layer 317 may be a thin film having a thickness of 0.1 μm to 50 μm, with a lower limit of 0.5 μm or more and an upper limit of 20 μm or less. The thickness of the odorant permeation layer 317 may be within the above numerical range throughout the entire odorant permeation layer 317, or the average thickness of the entire odorant permeation layer 317 may be within the above numerical range. When creating the odorant permeation layer 317, the thickness of the odorant permeation layer 317 can be controlled by regulating the area of ​​the film to be coated using electrode shape, etc., and by controlling the evaporation residue and dispensing amount of the odorant permeation layer solution. Odorants that permeate the odorant permeation layer 317 can reach the odorant receiving layer 315, but odorants that cannot permeate the odorant permeation layer 317 cannot reach the odorant receiving layer 315. If the odorant permeation layer 317 is too thick, fewer odorants will reach the odorant receiving layer 315, resulting in reduced measurement sensitivity. Furthermore, if the odorant permeation layer 317 inhibits the volume change of the odorant receiving layer 315, the change in electrical conductivity of the odorant receiving layer 315 caused by the odorant being adsorbed by the odorant receiving layer 315 will be reduced, resulting in a decrease in measurement sensitivity. On the other hand, if the odorant permeation layer 317 is insufficiently thick, most of the odorant will reach the odorant receiving layer 315. Therefore, the odorant permeation layer 317 will not be able to fully perform its function of selectively allowing odorants to reach the odorant receiving layer 315. Furthermore, an odorant permeation layer 317 that is not thick enough will not be able to adequately protect the odorant receiving layer 315. Therefore, it is preferable that the thickness of the odorant permeation layer 317 of the sensor element 31 according to the present invention be within the above-mentioned range.

[0020] <Method for measuring the thickness of the odorant permeable layer 317> The method for measuring the thickness of the odorant permeation layer 317 will be explained below with reference to FIG. 2. FIG. 2 is a scanning electron microscope (SEM) image of a cross section of a sensor element 31 including an odorant receiving layer 315 and an odorant permeation layer 317, observed at 25,000 magnification. The cross section of the sensor element 31 including the odorant receiving layer 315 and the odorant permeation layer 317 is formed using, for example, a cross-section polisher, specifically, an IB-19530CP (product name, manufactured by JEOL Ltd.). The lines indicated by symbols L1 to L20 in FIG. 2 indicate the length from the boundary between the odorant receiving layer 315 and the odorant permeation layer 317 at each location to the surface of the odorant permeation layer 317. Hereinafter, the length from the boundary between the odorant receiving layer 315 and the odorant permeation layer 317 to the surface of the odorant permeation layer 317 will be referred to as the cross-sectional length of the odorant permeation layer 317. The boundary between the odorant receiving layer 315 and the odorant permeable layer 317 can be determined using, for example, SEM reflection observation, electron image SEM-EDX, or STEM.

[0021] The thickness of the odorant-permeable layer 317 may be the average value of the cross-sectional lengths at multiple locations on the odorant-permeable layer 317. The measurement locations for the cross-sectional length that serve as the basis for calculating the thickness of the odorant-permeable layer 317 may be the two locations, the thickest and thinnest locations, or ten locations arbitrarily selected within the odorant-permeable layer 317, or even more. As an example, the average value of the cross-sectional lengths at 20 locations indicated by symbols L1 to L20 in the example shown in FIG. 2 may be the thickness of the odorant-permeable layer 317. The thickness of the odorant-permeable layer 317 may be determined as long as the average value of the cross-sectional lengths at multiple locations falls within the above-mentioned numerical range.

[0022] [2-2. Odor receptor layer] The odorant receiving layer 315 of the sensor element 31 contains a resin composition containing a resin (A) and a filler (B). This resin composition may further contain a surfactant (C). This resin composition is applied to a sensor element substrate, heated and dried to a dry solid, and then used as the odorant receiving layer 315. Resin (A), filler (B), and surfactant (C) will be described later with specific examples.

[0023] <Resin composition> In this specification, "odor substance" broadly refers to a substance that can be adsorbed onto the odor substance receiving layer 315. Therefore, it also includes substances that are not generally considered to be the cause of odor. "Odor" often contains multiple odor substances that cause it, and there are also substances that are not recognized as odor substances or unknown odor substances. One embodiment of the present invention focuses on the fact that the amount of odor substance adsorbed onto the odor substance receiving layer 315 varies depending on the type of odor substance.

[0024] In addition, even when the term "odorous substance" is simply used in this specification, it may refer to a "collection of odorous substances" that may contain multiple odorous substances, rather than an individual odorous substance.

[0025] Examples of "odor substances" include, but are not limited to, hexane, ethyl acetate, methanol, diethyl carbonate, toluene, d-limonene, bornan-2-one, cis-3-hexenol, β-phenylethyl alcohol, citral, L-carvone, γ-undecalactone, eugenol, linalyl acetate, menthol, benzaldehyde, vanillin, hexanal, ethanol, pentyl valerate, linalool, and 2-propanol.

[0026] In addition, in this specification, the term "odorant receiving layer" refers to a layer that adsorbs the odorant to be recognized. The odorant receiving layer 315 is formed from the resin composition described above. The odorant receiving layer 315 can be provided as part of the sensor element 31 described below.

[0027] The sensor described in Reference 1 is believed to be capable of detecting odors composed of single compounds. However, many odors are mixtures of multiple substances. The sensor described in Reference 1 lacks the ability to distinguish odor components in the detection section, resulting in insufficient odor discrimination performance for mixtures. Reference 2 demonstrates that by utilizing the differences in the chemical structure of the conductive polymers used in the detection section, the detection section can differentiate its response to various compounds via each conductive polymer, enabling the recognition of odor mixtures. However, the chemical structures of conductive polymers are limited, making it difficult to sensitively separate the response of the detection section to any odor component, making it difficult to distinguish between odors composed of similar components. Reference 3 proposes a method using a mixture of organic polymers, plasticizers, and conductive substances as the detection material in the detection section, detecting the penetration of odor components into the organic polymer as a change in the electrical resistance of the mixture. Taking advantage of the fact that different organic polymers with different compositions allow different odor components to penetrate, multiple detection sections made of the above detection material containing organic polymers of different compositions can be arranged in parallel to form an array, enabling the recognition of odor mixtures. However, with the organic polymers and organic polymers containing plasticizers described above, even if multiple combinations of organic polymers and conductive materials are prepared, the difference in chemical properties between the organic polymers is small, so the odor discrimination performance is insufficient. These conventional technologies cannot accurately detect, for example, real odor patterns where multiple substances interact or real odor patterns caused by substances with unknown compositions.

[0028] The electrical conductivity of the resin composition described above varies depending on the amount of odorant adsorbed to the resin composition. Furthermore, the adsorption process of odorants into the resin composition differs for each odorant. Therefore, by using such a resin composition, the sensor element 31 according to one embodiment of the present invention can improve its odor discrimination performance. For example, it can discriminate between real odor patterns in which multiple substances interact or real odor patterns caused by substances with unknown compositions.

[0029] <Resin (A)> The resin (A) contained in the resin composition according to one embodiment of the present invention is not particularly limited, and may be a urethane resin, a polyalkylene oxide, an acrylic resin, a fluorine-containing resin, a vinyl polymer resin (e.g., polyvinylpyrrolidone, polyvinyl butyral, etc.), a silicone resin, a polyamide resin, a polypropylene resin, paraffin wax, a polyester resin, etc. However, the resin (A) may be a R-SiO n (n is 1 or more and 3 / 2 or less) is not included.

[0030] <Filler (B)> A resin composition according to one embodiment of the present invention contains a filler (B). In this specification, the filler (B) refers to a conductive carbon material, more specifically, a carbon material having a volume resistivity of 0.1 Ω·cm or less. The resin composition is in a state in which the filler (B) is dispersed in the resin (A). The fillers (B) come into contact with each other to form conductive paths, thereby making the resin composition conductive.

[0031] Examples of the filler (B) include conductive carbon materials such as carbon black, carbon nanotubes, and graphene, pigments, silica, and metal powders.

[0032] Commercially available carbon black products include Ketjenblack EC (trade name, manufactured by Akzo, Netherlands), Ketjenblack EC-300J (trade name, manufactured by Lion Specialty Chemicals Co., Ltd.), Ketjenblack EC-600JD (trade name, manufactured by Lion Specialty Chemicals Co., Ltd.), Seast G116, 116 (trade names, manufactured by Tokai Carbon Co., Ltd.), Nitelon #10 (trade name, manufactured by Nippon Steel Chemical Co., Ltd.), Denka Black (trade name, manufactured by Denka Co., Ltd.), Toka Black (trade name, manufactured by Tokai Carbon Co., Ltd.), and SUPER C-65 (trade name, manufactured by MTI Corporation, USA).

[0033] Commercially available carbon nanotubes include VGCF-H (product name, manufactured by Showa Denko KK).

[0034] Commercially available graphene is manufactured by Sigma-Aldrich.

[0035] The conductive carbon material is preferably in the form of fibers or spheres.

[0036] When it is fibrous, the fiber diameter is preferably 0.1 to 10 μm, more preferably 0.1 to 5 μm, and the fiber length is preferably 0.1 to 10 μm, more preferably 1 to 10 μm.

[0037] When the particles are spherical, the primary particle size is preferably 10 nm to 200 nm, and more preferably 20 nm to 150 nm.

[0038] Furthermore, from the viewpoint of conductivity in the resin composition and sensor sensitivity, the conductive carbon material preferably has a primary particle diameter of 100 nm or less. The particle diameter of the conductive carbon material can be determined by a known method. For example, the particle diameter of the conductive carbon material can be measured by observing the material with a transmission electron microscope (TEM) and analyzing the image using an image processing device (e.g., Keyence Digital Microscope VHX-700F). When the conductive carbon material is a known or commercially available product, the particle diameter may be a literature value or a catalog value.

[0039] The content of the filler (B) is preferably 10 to 60% by weight, where the total amount of the resin (A) and the filler (B) is 100% by weight, from the viewpoint of ensuring that the sensor element formed from the resin composition exhibits sufficient conductivity as an odor sensor and sufficient sensitivity as the odor sensor. The content of the carbon black in the odorant receiving layer 315 may more preferably be 10 to 55% by weight, where the total amount of the resin (A) and the filler (B) is 100% by weight.

[0040] The resin composition may further contain other components in addition to the resin (A), filler (B), and surfactant (C) described above, as long as the effects of the present invention are obtained. Examples of other components include a solvent (D). The other components can be suitably used as long as both the effects of the present invention and the effects of the other components are obtained.

[0041] The solvent (D) can be added to the resin composition from the viewpoint of improving the compatibility between the resin (A) and the filler (B), improving the dispersibility of the surfactant (C) in the resin composition, or improving the coatability of the resin composition. Examples of the solvent (D) include N-methylpyrrolidone (also referred to as NMP), propylene glycol monomethyl ether acetate, ethyl butyrate, butyl butyrate, ethyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, toluene, and xylene.

[0042] The content of the solvent (D) in the resin composition can be appropriately determined from the above viewpoints.

[0043] <Surfactant (C)> The resin composition according to one embodiment of the present invention may contain a surfactant (C) as described below. The surfactant (C) acts as a dispersant for the filler (B). The surfactant (C) can be appropriately selected from known surfactants as long as the resin composition exhibits the above-mentioned effect.

[0044] The surfactant (C) is not particularly limited, but preferably has an HLB value of 8 to 18, more preferably 9 to 17, and particularly preferably 10 to 16. By using a surfactant (C) with such an HLB value, odor discrimination performance is improved.

[0045] The "HLB value" here is an index showing the balance between hydrophilicity and lipophilicity, and is known as a value calculated by the Oda method described, for example, in "Introduction to Surfactants" (published by Sanyo Chemical Industries, Ltd. in 2007, written by Takehiko Fujimoto), page 212, and is not a value calculated by the Griffin method.

[0046] The HLB value can be calculated from the ratio of the organic value to the inorganic value of an organic compound.

[0047] HLB=10×Inorganic / Organic Here, the inorganic and organic values ​​in the above formula represent index values ​​that express organic and inorganic properties proposed by Fujita et al., and can be calculated using the values ​​in the table on page 213 of the aforementioned "Introduction to Surfactants."

[0048] Examples of ionic surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

[0049] Examples of anionic surfactants include alkali metal salts of carboxylic acids having 10 to 24 carbon atoms, alkali metal salts of alkylsulfonic acids having 14 to 24 carbon atoms, and amine salts of polyether acid esters.

[0050] Examples of the carboxylic acid having 10 to 24 carbon atoms include decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, pentadecanoic acid, nonadecanoic acid, icosanoic acid, henicosanoic acid, docosanoic acid, tricosanoic acid, and tetracosanoic acid.

[0051] Examples of the alkyl group contained in the alkylsulfonic acid having 14 to 24 carbon atoms include a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a heneicosyl group, a docosyl group, a tricosyl group, and a tetracosyl group.

[0052] Examples of the alkali metal contained in the alkali metal salt include sodium and potassium.

[0053] Examples of cationic surfactants include halide salts of quaternary ammonium having an alkyl group having 12 to 24 carbon atoms.

[0054] Examples of the quaternary ammonium having an alkyl group having 12 to 24 carbon atoms include tetrapropylammonium, tetrabutylammonium, tetrapentylammonium, tetrahexylammonium, dimethyldioctylammonium, didecyldimethylammonium, decyltrimethylammonium, dodecyltrimethylammonium, tridecyltrimethylammonium, hexadecyltrimethylammonium, methyltrioctylammonium, octyltrimethylammonium, tributylmethylammonium, octadecyltrimethylammonium, tetradecyltrimethylammonium, nonadecyltrimethylammonium, icosyltrimethylammonium, heneicosyltrimethylammonium, heptadecyltrimethylammonium, and pentadecyltrimethylammonium.

[0055] Examples of the halide salt include fluoride salt, chloride salt, bromide salt, and iodide salt.

[0056] Examples of amphoteric surfactants include dimethyl(3-sulfopropyl)ammonium inner salts having an alkyl group with 10 to 22 carbon atoms, and N-alkyl-N,N-dimethylglycines having an alkyl group with 10 to 22 carbon atoms.

[0057] Examples of dimethyl(3-sulfopropyl)ammonium hydroxide inner salts having an alkyl group having 10 to 22 carbon atoms include decyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, undecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, dodecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, tridecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, tetradecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, and pentadecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt. Examples include hexadecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, hexadecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, heptadecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, octadecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, nonadecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, icosyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, heneicosyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, and docosyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt.

[0058] Examples of N-alkyl-N,N-dimethylglycines having an alkyl group with 10 to 22 carbon atoms include N-dodecyl-N,N-dimethylglycine and N-octadecyl-N,N-dimethylglycine.

[0059] Examples of nonionic surfactants include higher alcohol ethylene oxide adducts.

[0060] Examples of higher alcohols include 1-hexyl alcohol, 1-heptyl alcohol, 1-octyl alcohol, 1-nonyl alcohol, 1-decyl alcohol, 1-undecyl alcohol, 1-dodecyl alcohol, 1-tridecyl alcohol, 1-tetradecyl alcohol, 1-pentadecyl alcohol, 1-hexadecyl alcohol, 1-heptadecyl alcohol, and 1-octadecyl alcohol.

[0061] The number of moles of ethylene oxide added is preferably 5 to 50, more preferably 5 to 40, and even more preferably 5 to 30, from the viewpoint of odor discrimination performance.

[0062] The resin (A) and the filler (B) may or may not be compatible with each other.

[0063] The surfactant content is preferably 0 to 50% by weight, more preferably 10 to 40% by weight, and most preferably 20 to 30% by weight, based on 100% by weight of the total of resin (A), filler (B), and surfactant (C), from the viewpoint of sensitivity to odorous substances.

[0064] <Method of manufacturing resin composition> A specific example of the method for producing a resin composition according to one embodiment of the present invention is as follows.

[0065] The resin composition is obtained as a slurry by mixing the resin (A) and filler (B) and kneading them uniformly with a stirrer. When mixing the resin (A) and filler (B), a surfactant (C) and a solvent (D) may be added as needed. Examples of the stirrer include a planetary centrifugal mixer (ARE-310, a product name of Thinky Corporation) and a planetary centrifugal mixer (HR003-04A / V, a product name of Samsung Industries Co., Ltd.). The resin composition is obtained as a slurry with a desired porosity by mixing the resin (A) and filler (B) and kneading them with a stirrer at a rotation speed of 2000 rpm for a rotation time of approximately 10 to 60 minutes. When the surfactant (C) and solvent (D) are added as needed to the resin composition, the solvent (D) is removed by evaporation from the resin composition. The solvent (D) may be distilled off from the resin composition produced by uniformly mixing, or may be distilled off from the coating film produced during the production of the sensor element 31.

[0066] [2. Sensor element 31] The resin composition described above exhibits different changes in electrical conductivity over time when odorant A is adsorbed onto the resin composition than when odorant B, which is different from odorant A, is adsorbed onto the resin composition. By utilizing this property, a sensor element 31 capable of detecting and identifying odorants can be realized.

[0067] The following describes the outline and effects of a sensor element 31 to which a resin composition according to one embodiment of the present invention is applied.

[0068] The sensor element 31 includes an odorant receiving layer 315 containing the resin composition described above, a first metal wiring 313A, a second metal wiring 313B, and an odorant permeable layer 317. In the following, when there is no need to distinguish between the first metal wiring 313A and the second metal wiring 313B, they may be referred to as metal wiring 313.

[0069] Here, the first metal wiring 313A and the second metal wiring 313B will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a top view showing an example of the configuration of sensor element 31, and Fig. 4 is a cross-sectional view showing an example of the configuration of sensor element 31 shown in Fig. 3.

[0070] The first metal wiring 313A and the second metal wiring 313B are each metal wirings that function as electrodes for measuring changes in the electrical conductivity of the odorant receiving layer 315 (i.e., the resin composition). That is, the first metal wiring 313A and the second metal wiring 313B are spaced apart from each other, and the odorant receiving layer 315 is in contact with at least a portion of the first metal wiring and at least a portion of the second metal wiring. In one example, the first metal wiring 313A and the second metal wiring 313B are metal wirings that are not in direct contact with each other, and may be metal wirings that are approximately parallel to each other, as shown in FIG. 3.

[0071] As shown in FIG. 3, metal wiring 313 including first metal wiring 313A and second metal wiring 313B may be disposed on substrate 311. Substrate 311 may be a substrate such as glass epoxy commonly used in electronic circuits. Substrate 311 is not limited to glass epoxy, and may also be a substrate made of paper phenol, glass composite, polyimide, PET, glass ceramic, alumina, or aluminum. Metal wiring 313 may be metal wiring such as copper or gold. When viewed from a direction perpendicular to the surface of the substrate, the thickness of each of first metal wiring 313A and second metal wiring 313B is preferably 10 μm to 2 mm, more preferably 10 μm to 1 mm. When viewed from a direction parallel to the surface of the substrate, the height, i.e., thickness, of each of first metal wiring 313A and second metal wiring 313B is preferably 1 μm to 100 μm, more preferably 10 μm to 50 μm. The distance between first metal wiring 313A and second metal wiring 313B is preferably 1 μm to 3 mm, and more preferably 1 μm to 1.5 mm.The length of metal wiring 313 is preferably 100 μm to 50 mm, and more preferably 500 μm to 30 mm.

[0072] Figure 4 shows the AA cross section of Figure 3. The odorant receiving layer 315 may be in contact with at least a portion of the first metal wiring 313A and at least a portion of the second metal wiring 313B. For example, as shown in Figures 3 and 4, the odorant receiving layer 315 may be arranged to completely cover the first metal wiring 313A and the second metal wiring 313B. At least a portion of the odorant receiving layer 315 may be a thin film with a thickness of 1 μm to 50 μm, with the lower limit of the thickness being more preferably 3 μm or more and the upper limit of the thickness being more preferably 10 μm or less. If the thickness is less than 1 μm, the electrical resistance will be too high, making it difficult to obtain a good signal-to-noise ratio. Furthermore, if the thickness is more than 50 μm, it will take longer for the odorant to diffuse into the film, resulting in poor responsiveness to changes in odorant concentration. This configuration allows for accurate detection of changes in the electrical conductivity of the odorant receiving layer 315 due to the odorant being adsorbed by the odorant receiving layer 315 as an electrical signal. Furthermore, when creating the odorant receiving layer 315, the thickness of the odorant receiving layer 315 can be controlled by regulating the area of ​​the film to be coated using the electrode shape, etc., and by controlling the evaporation residue and the amount of the odorant permeable layer solution dispensed.

[0073] If the electrical conductivity of the odorant receiving layer 315 (i.e., the electrical conductivity of the sensor element 31) is low, it is desirable that the distance between the first metal wiring 313A and the second metal wiring 313B be a predetermined distance (for example, 500 μm) or less.

[0074] The sensor element 31 can detect and distinguish various odorants by using a resin composition that exhibits different changes in electrical conductivity over time when odorant A is adsorbed and when odorant B, which is different from odorant A, is adsorbed. The odor sensor 30, described below, may include multiple sensor elements 31 each having a substrate 311 on which an odorant detection structure (metal wiring 313 and odorant receiving layer 315) is provided. Each substrate 311 may be provided with multiple sets of odorant receiving layers 315 of the same composition. When multiple sensor elements 31 are provided, each sensor element 31 is provided with a constant-voltage power supply and a voltmeter. In the odor sensor 30, each substrate 311 may be provided with one odorant detection structure (metal wiring 313 and odorant receiving layer 315). Alternatively, the odor sensor 30 may include multiple sets of odorant detection structures (metal wiring 313 and odorant receiving layer 315) on a single substrate 311. In the latter case, a constant voltage power supply and a voltmeter are connected to each of the sets provided on the substrate 311 .

[0075] The compositions of the multiple odorant receiving layers 315 included in the odor sensor 30 may be the same or different. If the odor sensor 30 includes odorant receiving layers 315 with the same composition, the multiple odorant receiving layers 315 can each detect the same odorant. If the odor sensor 30 includes odorant receiving layers 315 with different compositions, each of the multiple odorant receiving layers 315 will respond differently to the odorant. In this way, by providing multiple sets of configurations for detecting odorants, the accuracy of odorant identification in the odor sensor 30 can be improved.

[0076] [3. Odor Sensor 30] The outline and effects of the odor sensor 30 to which the sensor element 31 is applied will be described below with reference to Fig. 5. Fig. 5 is a block diagram showing an example of the configuration of the odor sensor 30 to which the sensor element 31 is applied.

[0077] The odor sensor 30 includes a sensor element 31 that detects odor substances, a constant voltage power supply 32 (power supply), and a voltmeter 33 (measuring device).

[0078] The first metal wiring 313A and the second metal wiring 313B of the sensor element 31 are connected by a lead wire W. Fig. 5 shows an example in which a constant voltage power supply 32 and a voltmeter 33 are connected to the lead wire W.

[0079] The constant voltage power supply 32 is a power supply for supplying power to the sensor element 31. The constant voltage power supply 32 supplies a constant voltage via lead wires to the sensor element 31. The voltage value supplied by the constant voltage power supply 32 is 0.5V to 10V, for example, 2.5V.

[0080] The voltmeter 33 measures the potential difference that occurs between the first metal wiring 313A and the second metal wiring 313B when a constant voltage supplied from the constant voltage power supply 32 is supplied to the odorant receiving layer 315.

[0081] The odor sensor 30 includes an amplifier (not shown) in front of the voltmeter 33 in the circuit for measuring odor substances, and the amplifier amplifies the acquired signal and supplies it to the voltmeter 33.

[0082] In addition, the odor sensor 30 is equipped with a reference circuit in addition to the circuit for measuring odor substances, and the voltmeter 33 acquires the difference (potential difference) between the value acquired in the circuit for measuring odor substances and the value acquired in the reference circuit as a voltage value.

[0083] Although not an essential component, the odor sensor 30 may further include a housing 34. The housing 34 is a container capable of containing air containing odorous substances. When the housing 34 is included, the sensor element 31 is placed inside the housing 34.

[0084] The housing 34 has an inlet 341 for introducing an odorant and an outlet 342 for discharging air containing the odorant. The odorant may be introduced by introducing filter paper or the like soaked in the odorant into the housing 34 through the inlet 341, or by introducing air containing the odorant into the housing 34 through the inlet 341. The housing 34 is a container for containing air containing the odorant at a predetermined concentration (e.g., 200 ppm) or more.

[0085] Although not essential, an airflow generating fan 35 may be provided at the exhaust port 342 of the housing 34. The airflow generating fan 35 is used to generate an airflow inside the housing 34 and to exhaust gas inside the housing 34 from the exhaust port 342 to the outside of the housing 34.

[0086] The odor sensor 30 may include a constant current source (power supply) (not shown) instead of the constant voltage power supply 32, and an ammeter (measuring device) (not shown) instead of the voltmeter 33. In this case, the constant current source functions as a power source for supplying power to the sensor element 31, applying a constant current to the sensor element 31 via lead wires. Meanwhile, the ammeter measures the value of the current flowing between the first metal wiring 313A and the second metal wiring 313B when a constant current is applied to the odorant receiving layer 315. Both the first metal wiring 313A and the second metal wiring 313B can function as electrodes. Hereinafter, when the metal wiring 313 functions as an electrode, it may be referred to as the "electrode 313."

[0087] The odor sensor 30 outputs a measurement value that indicates the change over time in the electrical conductivity of the sensor element 31 before and after an odorant is adsorbed to the sensor element 31. This makes it possible to detect and distinguish various odorants.

[0088] 4. Odor Measuring Device 100 The odor sensor 30 described above can output the change in the electrical conductivity of the sensor element 31 over time for each odor substance when various odor substances are adsorbed to the sensor element 31. By applying this odor sensor 30, it is possible to compare the change in the electrical conductivity of the sensor element 31 over time when odor substance A is adsorbed to the sensor element 31 with the change in the electrical conductivity of the sensor element 31 over time when odor substance B is adsorbed to the sensor element 31. Based on the results of such comparison, an odor measuring device 100 can be realized that can estimate the odor substance adsorbed to the sensor element 31.

[0089] Furthermore, the odor measuring device 100 can estimate odor substances with high accuracy by using an estimation model 22 generated by machine learning. The estimation model 22 can be generated using training data that includes a combination of measurement values ​​measured when each of a plurality of odor substances is adsorbed onto at least one sensor element 31 and identification information specific to the odor substance that provided the measurement value.

[0090] The following describes the outline and effects of an odor measuring device 100 that uses the odor sensor 30. The odor measuring device 100 is a device that estimates odor substances adsorbed to a sensor element 31 based on changes in electrical conductivity that occur in the sensor element 31 to which the above-mentioned resin composition is applied.

[0091] The odor measuring device 100 of this embodiment is separately equipped with a sensor chamber 60 equipped with a plurality of sensor elements 31A (hereinafter also referred to as a "sensor element group 31A"), and a target sample receiving section 50 into which a target sample containing an odorant is introduced and into which gas containing the odorant generated from the target sample is enclosed. In this embodiment, each sensor element 31 included in the sensor element group 31A will be simply referred to as a "sensor element 31."

[0092] The odor measurement device 100 of this embodiment employs a configuration in which the gas containing the odorant inside the target sample receiving section 50 is pushed toward the sensor chamber 60 using a gas separate from the gas containing the odorant. In this embodiment, the gas inside the target sample receiving section 50 when the target sample is introduced into the target sample receiving section 50 (i.e., the gas containing the odorant to be detected) is referred to as the first gas. Meanwhile, the gas used to push the first gas toward the sensor chamber 60 is referred to as the second gas.

[0093] Fig. 1 is a schematic diagram of an odor measurement device 100. As shown in Fig. 1, the odor measurement device 100 includes an odor sensor 30, a target sample receiving unit 50, a sensor chamber 60, a gas supply unit 80, and an estimation device 10. The odor measurement device 100 may further include an adjustment unit 51. The odor measurement device 100 may further include an estimation device 10a.

[0094] 1 shows, as an example, an example in which gas flows from gas supply unit 80 to target sample receiving unit 50 and sensor chamber 60 in that order. Gas supply unit 80, target sample receiving unit 50, and sensor chamber 60 are each connected by a tube.

[0095] [Target sample receiving section 50] The target sample receiving section 50 can receive a target sample containing an odorant and retain a first gas. The target sample receiving section 50 has a first port 501 through which a second gas entering the target sample passes, and a second port 502 through which the first and second gases exiting the target sample can pass. In FIG. 1 , the first port 501 is located at the top of the target sample receiving section 50 and the second port 502 is located at the bottom of the target sample receiving section 50, but this is not limiting. For example, the positions of the first port 501 and the second port 502 can be appropriately set depending on the type and combination of odor components contained in the first gas. For example, the positions of the first port 501 and the second port 502 may be changed depending on whether the weight per unit volume (i.e., specific gravity) of the odor components contained in the first gas is heavier or lighter than that of the second gas. Furthermore, the target sample receiving section 50 may be provided with an airflow generating fan 35 therein, as in FIG.

[0096] The target sample receiving unit 50 includes a sample inlet 503 for receiving a liquid or solid target sample. The target sample receiving unit 50 may also include a mounting unit (not shown) for mounting the target sample. If the target sample is a liquid, the mounting unit may be a cup for holding the liquid, or if the target sample is a solid, the mounting unit may be a Petri dish on which the solid is placed. The target sample may be introduced into the target sample receiving unit 50 in a gaseous state as a first gas through the sample inlet 503. In this way, since the target sample receiving unit 50 can receive a liquid or solid target sample, it is possible to adjust the concentration of the odorant in the first gas. For example, even if the odorant is the same, it is easy to adjust the concentration of the odorant in the first gas.

[0097] The inner surface of the target sample receiving section 50 may be lined with a material that is inactive to odorants. A material that is inactive to odorants is a material that does not significantly change the concentration of each odorant contained in the gas sent to the sensor chamber 60. For example, a material that is inactive to odorants is a material that odorants are unlikely to adsorb or dissolve into. Examples of materials that are inactive to odorants include glass, metal, and resin. When using metal, stainless steel (SUS) is preferred, and when using resin, fluorine-based resin, polypropylene (PP), polyethylene (PE), ABS resin, and polyethylene terephthalate (PET) are preferred.

[0098] If the inner surface of the target sample receiving portion 50 is made of a material that adsorbs the odorous substances contained in the first gas, the odorous substances may be adsorbed to each portion, which may affect subsequent measurements.

[0099] Since the inner surface of the target sample receiving portion 50 is made of a material that is inactive to odorants, the risk of the material of the inner surface reacting with the odorants contained in the first gas, or the odorants being adsorbed onto the inner surface, is reduced. Therefore, the risk of the odorants contained in the first gas supplied to the sensor chamber 60 changing while contained in the target sample receiving portion 50, or the concentration of the odorants being diluted, is reduced.

[0100] Whether the target sample is a liquid or a solid, the odor measurement device 100 is provided with the target sample receiving section 50, thereby making the concentration of the first gas uniform within the target sample receiving section 50 before sending the first gas into the sensor chamber 60. Furthermore, by providing the target sample receiving section 50, the odor measurement device 100 is able to push the first gas into the sensor chamber 60 at a constant flow rate. This allows the odor measurement device 100 to send the first gas to the sensor chamber 60 under the same conditions each time, even when measurements are performed repeatedly, thereby enabling repeated, stable measurements.

[0101] The volume of the target sample receiving section 50 is preferably 1 to 200 times the volume of the sensor chamber 60. In particular, the volume of the target sample receiving section 50 is preferably larger than the volume of the sensor chamber 60. The volume of the target sample receiving section 50 is more preferably 2 or more times the volume of the sensor chamber 60, and even more preferably 4 or more times. Furthermore, the volume of the target sample receiving section 50 is preferably 100 or less times the volume of the sensor chamber 60, and even more preferably 60 or less times. By making the volume of the target sample receiving section 50 1 or more times the volume of the sensor chamber 60, the concentration of odor substances in the sensor chamber 60 is appropriately adjusted, and measurement results by the sensor provided in the sensor chamber 60 are stably output. Furthermore, by making the volume of the target sample receiving section 50 200 or less times the volume of the sensor chamber 60, it is easier to adjust the temperature and humidity within the target sample receiving section 50, which allows the sensor measurement results to be stably output and the odor measurement device 100 to be compact.

[0102] If the volume of the target sample receiving section 50 is less than one time the volume of the sensor chamber 60, the odor substances generated in the target sample receiving section 50 may be diluted in the sensor chamber 60, resulting in a decrease in the measurement sensitivity of the sensor. Furthermore, if the volume of the target sample receiving section 50 is more than 200 times the volume of the sensor chamber 60, the volume of the target sample receiving section 50 may be too large, reducing the uniformity of the concentration, temperature, and humidity of the first gas. This may make it impossible to deliver the first gas to the sensor chamber 60 under the same conditions when repeated measurements are performed. Furthermore, the overall size of the odor measurement device 100 may become larger.

[0103] FIG. 1 shows an example in which the volume of the target sample receiving portion 50 is eight times the volume of the sensor chamber 60 .

[0104] For example, if the inner surface of the tubular body 93 is made of a material that adsorbs odorous substances contained in the first gas, the odorous substances may be adsorbed to various parts, potentially affecting subsequent measurements. Therefore, it is preferable that the inner surface of the tubular body 93, which guides the first gas from the target sample receiving section 50 to the sensor chamber 60, be made of a material that is inactive to odorous substances, similar to the inner surface of the target sample receiving section 50. Examples of materials that are inactive to odorous substances include glass, metal, and resin. When using metal, stainless steel (SUS) is preferred, and when using resin, fluorine-based resin, polypropylene (PP), polyethylene (PE), ABS resin, and polyethylene terephthalate (PET) are preferred.

[0105] The target sample receiving section 50 may be configured to be detachable from the tubular bodies 92 and 93. In this way, since the target sample receiving section 50 is detachable, when the previous measurement is completed and the next measurement is to be performed, a new target sample receiving section 50 can be attached without purging the inside of the target sample receiving section 50. This allows the odor measuring device 100 to perform multiple measurements in a short period of time.

[0106] Furthermore, because the target sample receiving section 50 is detachable, the target sample receiving section 50 into which the target sample has been introduced can be maintained at a desired temperature using a temperature-retaining chamber separate from the odor measurement device 100. This allows the odor measurement device 100 to adjust the temperature of the target sample receiving section 50, even if the odor measurement device 100 cannot be provided with a regulator 51 (described later). The temperature-retaining chamber may be, for example, a water bath, a dry bath, a heat jacket, a silicon heater, a forward-air dryer, a thermo-hygrostat, a sprayer, or the like.

[0107] [Adjustment section 51] The adjustment unit 51 adjusts at least one of the temperature and humidity of the first gas contained in the target sample receiving unit 50. When the adjustment unit 51 adjusts the temperature, the adjustment unit 51 is, for example, a heater or a cooler. In this case, the adjustment unit 51 may be configured to cover the entire target sample receiving unit 50. When the adjustment unit 51 adjusts the humidity, the adjustment unit 51 is, for example, a humidifier or a dehumidifier. The adjustment unit 51 may adjust at least one of the temperature and humidity for each type of first gas, or may change at least one of the temperature and humidity at predetermined time intervals during measurement of the same first gas. The adjustment unit 51 may be, for example, a water bath, a dry bath, a heat jacket, a silicon heater, a forward-air dryer, a thermo-hygrostat, a sprayer, or the like, which is capable of changing at least one of the temperature and humidity.

[0108] By adjusting at least one of the temperature and humidity of the first gas in the target sample receiving section 50 using the adjusting section 51, the odor measuring device 100 can send the first gas to the sensor chamber 60 using conditions according to the type of the first gas (such as the weight or volatility of the gas). This also allows the odor measuring device 100 to send the first gas at a stable concentration to the sensor chamber 60, improving the accuracy of the measurement.

[0109] [Sensor Chamber 60] The sensor chamber 60 is a space that houses the sensor element 31 for measuring odor substances. The sensor chamber 60 is connected to the second port 502 of the target sample receiving portion 50. Specifically, the sensor chamber 60 includes a gas supply port 601 and a gas exhaust port 602, and the second port 502 of the target sample receiving portion 50 is connected to the gas supply port 601.

[0110] The sensor chamber 60 includes multiple sensor elements 31A capable of outputting measurement results corresponding to odor substances contained in the first gas. The multiple sensor elements 31A may each be a sensor element 31 having a different resin composition as a substance-receiving layer. That is, the multiple sensor elements 31A may have different sensitivities and specificities to odor substances. The sensor chamber 60 in FIG. 1 includes, as an example, sensor element 31 and sensor element 31b, but is not limited to this. The sensor chamber 60 in FIG. 1 also includes sensor element 31c having a different resin composition as a substance-receiving layer than sensor elements 31 and 31b. While sensor element 31 and sensor element 31b can output measurement results corresponding to the same odor substance contained in the first gas, the measurement results output by each sensor element are different. The measurement results corresponding to the odor substance are, for example, measurement results corresponding to the concentration of the odor substance. In the following description, unless there is a need to distinguish between sensor elements 31, 31b, 31c, and sensor element 31d (described later), they will be collectively referred to as "sensor element 31."

[0111] Sensor elements 31 each having a different resin composition as a substance receiving layer may be installed in any combination and in any arrangement in the sensor chamber 60. Furthermore, the sensor chamber 60 may be installed with a plurality of sensor elements 31 each having the same resin composition as a substance receiving layer.

[0112] Here, sensor element 31 and sensor element 31b may each be capable of outputting a measurement result corresponding to a different odorant. For example, sensor chamber 60 may be provided with sensor element 31 capable of outputting a measurement result corresponding to an odorant contained in a first gas, and sensor element 31b capable of outputting a measurement result corresponding to a second odorant different from the odorant contained in the first gas. For example, odor sensor 30 may include sensor elements 31 and 31b whose odorant receiving layers 315 use different resin compositions.

[0113] By providing multiple sensor elements 31 in which resin compositions with different odorant adsorption properties are used in the odorant receiving layer 315, the odor measuring device 100 can simultaneously perform estimations for multiple odorants. Note that as a sensor element 31 according to one embodiment of the present invention, a sensor element 31 that does not contain surfactant (C) in the odorant receiving layer 315 and a sensor element 31 that does contain surfactant (C) in the odorant receiving layer 315 may be used in combination.

[0114] Furthermore, by using the odor measurement device 100, it is possible to obtain, for each known odor substance, a first change pattern indicating a change in the electrical conductivity of the sensor element 31 and a second change pattern indicating a change in the electrical conductivity of the sensor element 31b. The estimation model 22 may be generated by machine learning using both the first change pattern and the second change pattern. The odor measurement device 100 estimates odor substances using the estimation model 22 generated in this way, and therefore can more precisely identify each odor substance.

[0115] 1 includes a plurality of sensor elements 31A arranged in a 4×4 array, as an example. The number of sensor elements 31A and the arrangement of the sensor elements 31A are not limited. The total number of sensor elements 31A included in the sensor chamber 60 is also not particularly limited, and may be, for example, 2, 8, 16, or 64. The total number of sensor elements 31A may be 8 or more and 16 or less.

[0116] The material of the inner surface of the sensor chamber 60 is preferably a material that is inactive to odorants, similar to the target sample receiving section 50. Examples of materials that are inactive to odorants include glass, metal, and resin. If metal is used, stainless steel (SUS) is preferable, and if resin is used, fluorine-based resin, polypropylene (PP), polyethylene (PE), ABS resin, and polyethylene terephthalate (PET) are preferable. If the material of the inner surface of the sensor chamber 60 is a material that adsorbs odorants contained in the first gas, adsorption of the odorants into the sensor chamber may reduce the amount of change in output from the sensor element 31 in subsequent measurements, potentially preventing the odor measuring device 100 from performing accurate measurements.

[0117] [Multiple sensor elements 31A (sensor element group 31A)] The sensor elements 31A may include a thin film. For example, the odorant receiving layer 315 and the odorant permeable layer 317 in FIGS. 2 and 3 are thin films.

[0118] As a mode for sending the first gas containing an odorant into the sensor chamber 60, for example, a vacuum pump may be installed on the gas outlet 602 side of the sensor chamber 60, and the gas may be drawn using the vacuum pump to send the odorant into the sensor chamber 60 from the gas supply port 601 side of the sensor chamber 60. However, if the sensor elements 31 and 31b are equipped with thin films, negative pressure within the sensor chamber 60 may cause the thin films to expand, preventing the sensor elements 31 and 31b from outputting stable measurement results. In the odor measurement device 100 according to this embodiment, the gas supply unit 80 pushes the gas from the first port 501 side of the sensor chamber 60 and the target sample receiving unit 50 to send the first gas into the sensor chamber 60, so the pressure within the sensor chamber 60 is positive. Therefore, the odor measurement device 100 can obtain stable measurement results even if multiple sensor elements 31A are equipped with thin films. In contrast, if the configuration is such that the gas supply unit 80 pushes the gas from the sensor chamber 60 and the first port 501 side of the target sample receiving unit 50 to send the first gas into the sensor chamber 60, the pressure inside the sensor chamber 60 will be positive. Therefore, it is preferable that the odor measurement device 100 according to this embodiment employs a configuration in which the gas supply unit 80 pushes the gas from the sensor chamber 60 and the first port 501 side of the target sample receiving unit 50 to send the first gas into the sensor chamber 60. This allows the odor measurement device 100 to obtain stable measurement results even if multiple sensor elements 31A are equipped with thin films.

[0119] The thin film of the plurality of sensor elements 31A may contain a conductive carbon material, a resin composition, and a surfactant.

[0120] [Gas supply unit 80] The gas supply unit 80 is connected to the first port 501 of the target sample receiving unit 50, and by sending a second gas into the inside of the target sample receiving unit 50, the first gas is sent from inside the target sample receiving unit 50 toward the sensor chamber 60.

[0121] A valve 81 may be provided between the gas supply unit 80 and the target sample receiving unit 50. By opening and closing the valve 81, the start and stop of gas supply from the gas supply unit 80 may be adjusted.

[0122] In this way, the gas supply unit 80 pushes the gas from the first port 501 side of the target sample receiving unit 50 to send the first gas into the sensor chamber 60, so the pressure inside the sensor chamber 60 is positive. This allows the odor measurement device 100 to obtain stable measurement results. Furthermore, because the second gas can be sent by opening and closing the valve 81, the odor measurement device 100 can send the first gas from the target sample receiving unit 50 toward the sensor chamber 60 at any timing. This allows the odor measurement device 100 to improve the reproducibility of the waveform shape output by each sensor element 31 when repeatedly measuring odor substances contained in the first gas using the sensor element group 31A.

[0123] The second gas may be an inert gas or air. Examples of inert gases include argon and nitrogen. When the second gas is an inert gas, the gas supply unit 80 may be a gas cylinder.

[0124] Furthermore, when the second gas is air, the gas supply unit 80 may be a pump. In this case, in order to remove components that react with the first gas contained in the target sample receiving unit 50, the odor measuring device 100 may be provided with, for example, an activated carbon filter, a dehumidifying agent, a silica gel column, or a dust filter on the first port 501 side of the target sample receiving unit 50.

[0125] The odor measuring device 100 may further include a mass flow controller on the side of the first port 501 of the target sample receiving section 50, more specifically, between the valve 81 and the gas supply section 80. The odor measuring device 100 employing this configuration can send the first gas from the target sample receiving section 50 to the sensor chamber 60 at a constant flow rate, and the multiple sensor elements 31A can produce stable outputs.

[0126] 1 shows a configuration in which the first gas and the second gas leaving the inside of the target sample receiving section 50 pass through the pipe 93 and the sensor chamber 60, but this configuration is not limited to this. Because the target sample receiving section 50 of the odor measurement device 100 has a larger volume than the sensor chamber 60, it is not necessary to send all of the first gas inside the target sample receiving section 50 to the sensor chamber 60 during measurement. Furthermore, when the inside of the target sample receiving section 50 is purged with the second gas after measurement, the target sample receiving section 50 and the sensor chamber 60 do not need to be connected. Therefore, the odor measurement device 100 may be configured such that a valve (not shown) is provided in the pipe 93 so that the first gas and the second gas leaving the inside of the target sample receiving section 50 can be exhausted without passing through the sensor chamber 60.

[0127] [Estimation device 10] The estimation device 10 estimates odor substances detected by the odor sensor 30. The estimation device 10 is, for example, a computer equipped with a CPU and memory (not shown). The estimation device 10 is communicatively connected to the odor sensor 30. Specifically, the estimation device 10 performs odor substance estimation by analyzing measurement values ​​acquired from the odor sensor 30. If the sensor chamber 60 further includes a sensor element 31c whose substance receiving layer 315 uses a resin composition different from that of the sensor elements 31 and 31b, the estimation device 10 may supply a constant voltage to the sensor element 31c and acquire and analyze measurements measured by a voltmeter. The estimation device 10 may also display the measurement values ​​themselves, waveforms plotting the measurement values, and estimation results for unknown odor substances based on an estimation model. The estimation device 10 may also display numerical values ​​and graphs showing changes in the abundance ratios of each odor substance in a gas containing multiple odor substances. The estimation device 10 may also generate an estimation model 22 used to estimate odor substances.

[0128] <Generation of Estimation Model 22> Next, the configuration of the odor measurement device 100 that performs the process of generating the estimation model 22 used to estimate odor substances, and the process of generating the estimation model 22 will be described with reference to FIGS. 6 and 7. FIG.

[0129] The estimation model 22 is generated by machine learning using training data that includes a combination of measurements taken by the voltmeter 33 when each of a plurality of odor substances is adsorbed onto at least one sensor element 31 and identification information specific to the odor substance that provided the measurements. Here, the identification information specific to the odor substance may be, for example, the name, CAS number, and chemical formula of the odor substance.

[0130] (Configuration of the estimation device 10 (generation of the estimation model 22)) Fig. 6 is a functional block diagram showing an example of the configuration of the odor measuring device 100. For ease of explanation, the same reference numerals are used to denote components having the same functions as those described in Fig. 1, and their description will not be repeated.

[0131] As shown in FIG. 6, the estimation device 10 includes an input unit 15, a control unit 1, and a storage unit 2.

[0132] The input unit 15 is for receiving various input operations from the user, and may be, for example, a keyboard, a mouse, a touch panel, or the like.

[0133] The control unit 1 includes a measurement value acquisition unit 11 (acquisition unit), a change pattern analysis unit 12 (analysis unit), a learning control unit 13, and an estimation model generation unit .

[0134] The measurement value acquiring unit 11 acquires a measurement value from the voltmeter 33. Furthermore, the measurement value acquiring unit 11 uses the acquired measurement value to calculate a value indicating the electrical conductivity of the sensor element 31 (for example, a resistance value, an impedance, etc.). The measurement value acquiring unit 11 may acquire the measurement value from the voltmeter 33 at predetermined time intervals (for example, every 0.1 seconds).

[0135] The change pattern analysis unit 12 analyzes the change over time in the electrical conductivity of at least one sensor element 31. Using the resistance value calculated by the measurement value acquisition unit 11, the change pattern analysis unit 12 calculates a value indicating the amount of change in the electrical conductivity of the sensor element 31 due to the adsorption of an odorant. The change pattern analysis unit 12 generates data indicating a change pattern that indicates the change over time in the calculated amount of change in electrical conductivity. If the generated change pattern is for a known odorant, the change pattern analysis unit 12 may associate the generated change pattern with identification information specific to the known odorant and store it in the change pattern database 21 (learning data).

[0136] The learning control unit 13 reads the change pattern database 21 from the storage unit 2 and controls the generation of the estimation model 22 by machine learning. Here, the change pattern database 21 is a database containing combinations of measurement values ​​measured when multiple odor substances are adsorbed onto the sensor element 31 and identification information unique to the known odor substances that provided the measurement values. The learning control unit 13 inputs the change patterns read from the change pattern database 21 to the estimation model generation unit 14. In addition, the learning control unit 13 compares the identification information of the odor substances corresponding to the change pattern input to the estimation model generation unit 14 with the estimation results output from the estimation model generation unit 14, and outputs correction instructions to the estimation model generation unit 14 according to the comparison results.

[0137] The estimation model generation unit 14 generates the estimation model 22 by a machine learning algorithm using the change patterns stored in the change pattern database 21. The estimation model generation unit 14 may be configured to generate the estimation model 22 by using a known supervised machine learning algorithm. Examples of machine learning algorithms that can be applied to the estimation model generation unit 14 include the k-nearest neighbor method, logistic regression, support vector machines, random forests, and neural networks.

[0138] Feature extraction method When generating an estimation model by machine learning, the base data may be the measurement values ​​themselves, or may be data extracted from feature quantities of the measurement values, such as statistical quantities of the measurement values, differential integral values, peak detection values, or autocorrelation values. Examples of statistical quantities include the mean value, variance, maximum value, minimum value, difference between the maximum and minimum values, and standard deviation. Examples of differential integral values ​​include the slope and area. Examples of peak detection values ​​include the number of peaks and height. Examples of autocorrelation values ​​include the step difference.

[0139] Pretreatment method When generating an estimation model using machine learning, the base data may be used directly for machine learning, or the base data may be preprocessed as necessary. Furthermore, when preprocessing is performed, the preprocessing may be performed before feature extraction, after feature extraction, or both before and after feature extraction. The preprocessing may be performed by a known method, such as correction, noise removal, standardization, data conversion, smoothing, and data expansion. Correction may be performed based on the measurement results of multiple elements, commercially available sensors (e.g., temperature sensors, humidity sensors, etc.), and standard gases. For example, correction may be performed by output ratio calculation, independent component analysis (ICA), statistical calculation, integration, addition, subtraction, division, etc. Noise removal may include, for example, removal of outliers and white noise. Standardization may include, for example, normalization and regularization. Data transformation may include, for example, trend removal, frequency transformation, logarithmic transformation, etc. Smoothing may include, for example, moving average and difference. Examples of data augmentation include adding the same sample data (for example, assuming a normal distribution) and adding new sample data (for example, adding by using a vector mixture ratio).

[0140] Machine learning algorithms Machine learning algorithms applicable to the estimation model generation unit 14 include regression analysis, classification, tree, time series analysis, neural network, clustering, etc. Examples of regression analysis include logistic regression, Lasso, elastic net, support vector regression (SVR), linear, Ridge, ensemble regression, etc. Examples of classification include k-nearest neighbor method, support vector classification (SVC), Naive Bayes classifier, stochastic gradient descent (SGD), kernel approximation, etc. Examples of trees include decision trees, regression trees, random forests, boosting (lightGBM, XGboost), stacking, etc. Examples of time series include AR, MA, ARIMA, state space, etc. Examples of neural networks include multi-layer perceptrons (MLPs), convolutional neural networks (CNNs), recurrent neural networks (RNNs), residual neural networks (ResNets), transformers, graph neural networks (GNNs), etc. Examples of clustering methods include Gaussian mixture models (GMMs), k-means (kmeas), minikmeans, variational Gaussian mixture models (VBGMMs), kernel approximation, etc.

[0141] (Process for generating estimation model 22) The process of generating an estimation model 22 using the odor measurement device 100 will be described below with reference to FIG. 7. FIG. 7 is a flowchart showing an example of the process flow of the estimation device 10 of the odor measurement device 100 generating the estimation model 22. The estimation model 22 is generated by machine learning using training data including a combination of measurement values ​​measured by the voltmeter 33 when each of a plurality of odor substances is adsorbed to at least one sensor element 31, and identification information unique to the odor substance that provided the measurement value. Here, the identification information unique to the odor substance may be, for example, the name of the odor substance, a CAS number, a chemical formula, etc.

[0142] First, the measurement value acquiring unit 11 acquires the voltage value V0 measured by the odor sensor 30 before the odor substance is introduced into the target sample receiving unit 50, and calculates the resistance value R0. The resistance value R0 is preferably 500 to 3000 Ω, more preferably 800 to 2800 Ω, and most preferably 1000 to 2500 Ω. Then, the odor substance is introduced into the target sample receiving unit 50 (Step S1).

[0143] Meanwhile, the input unit 15 receives input such as the name of the known odor substance introduced into the target sample receiving unit 50 (step S2). The processing of step S2 may be performed before step S1.

[0144] Next, the measurement value acquiring unit 11 acquires data (waveform or pattern of change over time) of the amount of change (ΔV) in the voltage value V before and after the odorant is adsorbed and desorbed to the sensor element 31 (step S3).

[0145] Next, the change pattern analysis unit 12 associates the change (ΔV) data (waveform or time-dependent change pattern) in the voltage value V before and after the odor substance adsorption / desorption process with the name of the input known odor substance and stores it in the change pattern database (step S4).

[0146] If no change patterns are stored for the predetermined types of existing odor substances (NO in step S5), that is, if there is still insufficient data to use for machine learning, the process returns to step S1.

[0147] If a change pattern is stored for a predetermined type of existing odor substance (YES in step S5), the learning control unit 13 reads out the change pattern for the known odor substance stored in the change pattern database 21 and inputs it to the estimation model generation unit 14. The estimation model generation unit 14 generates an estimation model 22 by machine learning based on the time-dependent change pattern (or feature extracted from the change pattern) stored in the change pattern database 21 (step S6).

[0148] The estimation model generation unit 14 stores the estimation model 22 generated by predetermined machine learning in the storage unit 2 (step S7).

[0149] 6 and 7, the estimation device 10 generates the estimation model 22, but this is not limiting. For example, the estimation device 10 may provide the same data as the change pattern database 21 to an external computer different from the estimation device 10 that has the same functions as the learning control unit 13 and the estimation model generation unit 14, and have the computer generate the estimation model 22.

[0150] <Identification of odor substances> Next, the configuration of the odor measurement device 100a that estimates odor substances using the estimation model 22 and the estimation process will be described with reference to FIGS.

[0151] (Configuration of Estimation Device 10a (Execution of Estimation Process)) Fig. 8 is a functional block diagram showing an example of the configuration of the odor measuring device 100a. For ease of explanation, the same reference numerals are used to denote components having the same functions as those described in Fig. 1 and Fig. 6, and their description will not be repeated.

[0152] As shown in Fig. 8, the estimation device 10a includes a control unit 1a, a storage unit 2a, and an output unit 18. Here, Fig. 8 shows a configuration example in which the estimation device 10 shown in Fig. 6 is used for odor substance estimation processing. In other words, the estimation device 10 shown in Fig. 6 and the estimation device 10a shown in Fig. 8 may be computers with the same hardware configuration.

[0153] The output unit 18 is for presenting the estimation result to the user, and may be, for example, a display, a speaker, a lamp, or the like.

[0154] The control unit 1 a includes a measurement value acquisition unit 11 (acquisition unit), a change pattern analysis unit 12 (analysis unit), an estimation unit 16, and an output control unit 17.

[0155] The estimation unit 16 uses the estimation model 22 to estimate the odor substance from the analysis results obtained by analyzing the measurement values ​​acquired from the odor sensor 30.

[0156] The output control unit 17 controls the output unit 18 to output the estimation result.

[0157] (Estimation process) Specific processes performed by each unit of the control unit 1a will be explained below with reference to Fig. 9. Fig. 9 is a flowchart showing an example of the process flow for the estimation device 10a to estimate an odor substance.

[0158] First, the measurement value acquiring unit 11 acquires the voltage value V0 measured by the odor sensor 30 before the odor substance is introduced into the target sample receiving unit 50, and calculates the resistance value R0. Then, an unknown odor substance (regardless of its properties) is introduced into the target sample receiving unit 50 (step S11).

[0159] Next, the measurement value acquisition unit 11 acquires data (waveform or time-dependent change pattern) of the change (ΔV) in the voltage value V before and after the adsorption and desorption of the unknown (i.e., the target) odor substance to the sensor element 31 (step S12).

[0160] Next, the estimation unit 16 estimates the unknown odor substance from the time-dependent change pattern (or the feature amount extracted from the change pattern) based on the estimation model 22 (step S13).

[0161] The output control unit 17 controls the output unit to output the estimation result (step S14).

[0162] In the above embodiment, the estimation device 10 that generates the estimation model 22 and the estimation device 10a that estimates odor substances using the estimation model 22 have been described. Note that the estimation device 10 and the estimation device 10a may be separate devices or may be a single device.

[0163] <Configuration example of sensor element 31c> FIG. 10 is a top view showing an example of the configuration of one sensor element 31c included in the sensor element group 31A. The sensor element 31c includes an electrode 313, which is a metal wiring arranged on a substrate 311, and a circular odorant receiving layer 315c formed on the electrode 313. The electrode 313 includes a first metal wiring 313C and a second metal wiring 313D. The first metal wiring 313C and the second metal wiring 313D are each metal wirings that function as electrodes for measuring changes in the electrical conductivity of the odorant receiving layer 315c. In FIG. 10, the metal wiring 313a and the metal wiring 313d are arranged on the front side of the substrate 311 (i.e., the front side of the paper) and are in contact with the odorant receiving layer 315c. Meanwhile, the metal wiring 313b and the metal wiring 313c are connected to the metal wiring 313a and the metal wiring 313d, respectively, on the front side of the substrate 311 and penetrate the substrate 311 toward the back side. Therefore, the metal wiring 313b and the metal wiring 313c are not in contact with the odorant receiving layer 315c. The diameter R of the odorant receiving layer 315c is 0.2 mm or more and 5 mm or less. In FIG. 10, the shape of the odorant receiving layer 315c provided in the sensor element 31c is elliptical as an example, but is not limited to this. If the shape of the odorant receiving layer 315c is elliptical, the average of the minor axis and the major axis may be 0.2 mm or more and 5 mm or less. The shape of the odorant receiving layer 315c may also be a perfect circle.

[0164] As shown in FIG. 10, the metal wiring 313a and the metal wiring 313d are in contact with the odorant receiving layer 315c but are not in contact with the odorant permeable layer 317.

[0165] FIG. 11 is a top view showing an example of the configuration of one sensor element 31d included in the sensor element group 31A. The sensor element 31d comprises an electrode 313 (first metal wiring 313C, second metal wiring 313D) arranged on the substrate 311, and a strip-shaped odorant receiving layer 315d formed on the electrode 313. The length W of the short width of the odorant receiving layer 315d is 0.2 mm or more and 5 mm or less. In the following description, when there is no need to distinguish between the odorant receiving layers 315c and 315d, they will be collectively referred to as the "odorant receiving layer 315."

[0166] The electrodes of the sensor elements 31 included in the sensor element group 31A each have a first electrode and a second electrode, and the first and second electrodes may be arranged in the form of parallel lines, parallel curves, a comb shape, or concentric circles. Regardless of the shape adopted, the first and second electrodes are preferably arranged in line symmetry or point symmetry with each other. By arranging the first and second electrodes in this manner, the odor measuring device 100 can measure odor substances contained in gas with high accuracy.

[0167] The sensor element 31c in Fig. 10 has a first metal wiring 313C and a second metal wiring 313D. Furthermore, as an example, the first metal wiring 313C is a first electrode composed of a metal wiring 313a and a metal wiring 313b, and the two metal wirings are arranged in a T-shape so as to be perpendicular to each other. The second metal wiring 313D is a second electrode composed of two metal wirings 313c and 313d, similar to the first metal wiring 313C, and is configured so as to be arranged in a T-shape so as to be perpendicular to each other. Furthermore, the first metal wiring 313C and the second metal wiring 313D are arranged in parallel lines so that the metal wiring 313a and the metal wiring 313c face each other.

[0168] The first metal wiring 313C and the second metal wiring 313D are particularly arranged in a T-shape, which allows the first metal wiring 313C and the second metal wiring 313D to be located at a suitable distance from each other, thereby stabilizing the electrode resistance. For example, if the electrodes were arranged in a comb shape, the distance between the electrodes would be too short, which could result in the electrode resistance being too low. Furthermore, the first metal wiring 313C and the second metal wiring 313D are arranged in a T-shape, which allows the slurry to spread easily in the application process of the sensor element 31 (described later) because there are no uneven portions of the electrode that could hinder the slurry from spreading. Furthermore, the ease of spreading the slurry also contributes to a consistent thickness of the odorant receiving layer 315 after drying.

[0169] 12 is a perspective view showing an example of the configuration of one sensor element 31c included in the sensor element group 31A. As shown in FIG. 12, in sensor element 31c, first metal wiring 313C and second metal wiring 313D are each connected to pins 316 at ends of the first metal wiring 313C and second metal wiring 313D that do not face each other. Pins 316 are conductive members for electrically connecting first metal wiring 313C and second metal wiring 313D to other components of the odor sensor 30. Although not shown, sensor elements 31c and 31d shown in FIGS. 10 and 11 also include pins 316 shown in FIG. 12.

[0170] <Method of manufacturing the sensor element 31> The following describes a manufacturing method for manufacturing the various types of sensor elements 31 used in the odor measuring device 100. The odorant-receiving layer 315 of the sensor element 31 can use slurries with various compositions as its raw material.

[0171] (Slurry preparation process) First, multiple types of slurries with different mixing ratios of conductive carbon material and resin composition are prepared. The mixing ratio of the conductive carbon material and resin composition can be appropriately set depending on the desired sensitivity and detection specificity of the odorant receiving layer 315. The slurry may contain a solvent, additives, and surfactants in addition to the conductive carbon material and resin composition. When preparing / kneading a slurry of a resin composition containing a filler and a resin composition, NMP as a solvent may be added to the mixture of filler and resin composition in multiple batches, and the kneading may be repeated. Note that the porosity of the cross section of the odorant receiving layer 315 decreases by increasing the number of kneading repetitions.

[0172] (Electrode placement process) Next, electrodes are arranged on the substrate. The electrodes may include a first electrode and a second electrode. The first electrode and the second electrode may be arranged in parallel straight lines, parallel curved lines, a comb shape, or concentric circles. In addition, regardless of which shape the first electrode and the second electrode are arranged in, it is preferable that they are arranged in line symmetry or point symmetry with each other. Furthermore, it is more preferable that the first electrode and the second electrode are arranged in parallel straight lines or parallel curved lines. It is particularly preferable that the first electrode and the second electrode are arranged in the shapes shown in Figures 10 and 11. Specifically, first metal wiring 313C is preferably configured with two metal wirings (313a and 313c) arranged perpendicular to each other in a T-shape, second metal wiring 313D is preferably configured with two metal wirings (313c and 313d) arranged perpendicular to each other in a T-shape, and first metal wiring 313C and second metal wiring 313D are preferably arranged in parallel lines such that metal wiring 313a and metal wiring 313c face each other. By arranging the first metal wiring and second metal wiring in this manner, odor measuring device 100 can measure odor substances contained in gas with high accuracy.

[0173] As an example, in Figures 10 and 11, one set of electrodes (first metal wiring 313C and second metal wiring 313D) is arranged on one substrate 311, but multiple sets of electrodes may be arranged side by side on one substrate.

[0174] (Area definition process) Next, coating areas onto which the plurality of types of slurries are to be coated are defined on the substrate on which the electrodes are disposed. The coating areas may be defined, for example, by disposing a resist. Furthermore, if the slurry is dropped from a nozzle in the coating process, the coating areas may be defined to match the nozzle diameter. The resist M is disposed so as to define the coating areas 330. In the coating areas 330, the substrate 311 is exposed.

[0175] The size of the coating area 330 may be specified to be the same for each of the multiple types of slurries. That is, even if the slurries have different mixing ratios of the conductive carbon material and the resin composition, the area of ​​the coating area 330 for applying the slurries may be uniform. This reduces the variation in the area of ​​the multiple types of odorant receiving layer 315 after drying, even when multiple types of slurries with different mixing ratios are used.

[0176] The coated area 330 is circular as an example, but the shape of the coated area 330 is not limited to this. The coated area 330 may be circular or strip-shaped. This results in the formation of a circular or strip-shaped odorant receiving layer 315.

[0177] When the shape of the application area 330 is circular, the diameter of the circle may be 0.2 mm or more and 5 mm or less, and when the shape of the application area 330 is strip-shaped, the length of the strip in the short direction may be 0.2 mm or more and 5 mm or less. This results in the formation of a circular odorant receiving layer 315c with a diameter of 0.2 mm or more and 5 mm or less, and a circular odorant receiving layer 315d with a strip-shaped length in the short direction of 0.2 mm or more and 5 mm or less.

[0178] The method for applying the resist M is not particularly limited, but examples include a method of silk-screening the solder resist in a specified area and then UV-curing the solder resist, a method of attaching a resist film to a substrate, and a method of curing only the resist in a specified area and removing the uncured portion.

[0179] (Coating process) Next, each of the multiple types of slurries is applied to the application region 330. The method for applying the slurries can be a conventionally known method, and the slurries may be applied by dripping from a nozzle, spraying, or spin coating. The method for applying the slurries by dripping from a nozzle is particularly preferable, and a desired application shape can be obtained by using, for example, an IMAGE MASTER 350 PC Smart manufactured by Musashi Engineering Inc. with a SUS metal needle nozzle (inner diameter 0.1 mmΦ, outer diameter 0.23 mm).

[0180] (drying process) Finally, the slurry applied to the application area 330 is dried to form the odorant receiving layer 315. The method for drying the slurry is not particularly limited, but for example, it can be heated by infrared heating at 100°C under normal pressure for 1 hour, and then heated at 100°C for 1 hour while reducing the pressure in a vacuum dryer.

[0181] (Odor permeable layer adjustment process) By kneading various resin compositions with NMP, a solution containing the resin for the odorant-permeable layer 317 is prepared. Note that by repeating the kneading process more times, the porosity of the cross section of the odorant-permeable layer 317 decreases.

[0182] (Overlay of odorant permeable layer 317) A solution of resin for the odorant permeation layer 317 is applied onto the dried odorant receiving layer 315. At this time, care is taken to ensure that no gaps are formed between the odorant receiving layer 315 and the odorant permeation layer 317. The application method can be the same as the method described above in the (application step). The drying method after application can also be the same as the method described above in the (drying step).

[0183] <Software implementation example> The control block (particularly the control unit 1) of the estimation device 10, 10a may be realized by a logic circuit (hardware) formed on an integrated circuit (IC chip) or the like, or may be realized by software.

[0184] In the latter case, the estimation device 10, 10a includes a computer that executes instructions of a program, which is software that realizes each function. This computer includes, for example, one or more processors and a computer-readable recording medium that stores the program. The object of the present invention is achieved when the processor in the computer reads and executes the program from the recording medium. The processor may be, for example, a central processing unit (CPU). The recording medium may be a "non-transitory tangible medium," such as a read-only memory (ROM), a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit. The device may also include a random access memory (RAM) for loading the program. The program may be supplied to the computer via any transmission medium capable of transmitting the program (such as a communication network or broadcast waves). Note that one aspect of the present invention may also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[0185] 〔summary〕 The sensor element according to the first aspect of the present disclosure comprises an odorant receiving layer comprising a resin composition containing a resin (A) and a filler (B), a first metal wiring in contact with at least a portion of the odorant receiving layer, a second metal wiring spaced apart from the first metal wiring and in contact with at least a portion of the odorant receiving layer, and an odorant permeation layer covering at least a portion of the odorant receiving layer opposite the side in contact with the first metal wiring and the second metal wiring, wherein the odorant permeation layer is composed of R1-SiO 3 / 2 and a structure represented by R2-SiO1, wherein R1 is a hydrocarbon group having 1 or more and 18 or less carbon atoms.

[0186] A sensor element according to a second aspect of the present disclosure is the sensor element according to the first aspect, wherein at least a portion of the odorant-permeable layer is in the form of a thin film having a thickness of 0.1 μm or more and 50 μm or less.

[0187] A sensor element according to a third aspect of the present disclosure is the sensor element according to the first or second aspect, wherein the odorant receiving layer is R—SiO 3 / 2 The composition may not include a composition having a structure represented by the formula:

[0188] The sensor element according to aspect 4 of the present disclosure is any one of aspects 1 to 3, wherein at least a portion of the odorant receiving layer is in the form of a thin film having a thickness of 1 μm or more and 50 μm or less.

[0189] A sensor element according to a fifth aspect of the present disclosure is the sensor element of any one of the first to fourth aspects, wherein the filler (B) is a conductive carbon material.

[0190] A sensor element according to a sixth aspect of the present disclosure is the sensor element of any one of the first to fifth aspects, wherein R1 may be one or more of a methyl group, an aliphatic hydrocarbon group, and an aromatic group.

[0191] A sensor element according to aspect 7 of the present disclosure is any one of aspects 1 to 6 above, wherein R2 may be one or more of a hydrogen atom, a methyl group, an alkyl group, an amino group, a hydroxyl group, a carboxyl group, a fluoromethyl group, a polyester group, and a polyether group.

[0192] A sensor element according to aspect 8 of the present disclosure, in any one of aspects 1 to 7 above, may have a content of the filler (B) of 10 to 50% by weight, where the total amount of the resin (A) and the filler (B) is 100% by weight.

[0193] An odor measuring device according to a ninth aspect of the present disclosure includes a plurality of sensor elements according to any one of the first to eighth aspects. [Example]

[0194] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, % means % by weight and parts means parts by weight.

[0195] <R1-SiO 3 / 2 > The following was used: S1: KR-271 (methyl / phenyl silicone resin) S2: KR-480 (methyl / phenyl silicone resin) S3: KR-251 (methyl silicone resin) All of the above are manufactured by Shin-Etsu Chemical Co., Ltd.

[0196] <r2-sio1> The following were used. S4: KF3935 (Side-chain higher aliphatic amide-modified silicone oil) S5: X22-3710 (One-terminal carboxyl group-modified silicone oil) S6: X22-1877 (Side-chain alkyl·aralkyl-modified silicone oil) S7: FL-100-1000cs (Fluoromethyl-containing modified silicone oil) S8: KF-6123 (Polyether, hydroxyl group-containing modified silicone oil) All of the above are manufactured by Shin-Etsu Chemical Co., Ltd.

[0197] Also, as R2-SiO1, S9 obtained as follows was used. <Preparation of S9> Into a glass flask, 300 parts of xylene, 20 parts of KF-101 (glycidyl group-modified silicone oil) manufactured by Shin-Etsu Chemical Co., Ltd., and 0.04 part of dibutyltin were added to 100 parts of FINEDIC FD-305 (polyester resin) manufactured by DIC Corporation. After reacting for 12 hours under reflux conditions at 140°C, it was cooled and isopropyl alcohol was gradually added. When it became turbid, the unnecessary components were filtered off and dried. When the structure was confirmed by NMR, it was confirmed that the obtained product was polyester-modified silicone oil (S9).

[0198] <Other Resins> Z1: PEG4000 (polyethylene glycol) manufactured by Fuji Film Wako Pure Chemical Corporation.

[0199] <Resin (A)> A5: Mobiltal B14S (polyvinyl butyral resin) manufactured by Kuraray Co., Ltd.

[0200] <Preparation of A6> [Preparation of Polyester Amide (A6)] A reaction vessel equipped with a condenser, a water separation tube, a heating / cooling device, a thermometer, a stirrer, and a nitrogen inlet tube was charged with 150 parts of xylene and 120 parts of a 20% aqueous solution of polyallylamine ("PAA-03" manufactured by Nittobo Medical Co., Ltd., average molecular weight approximately 3,000). The mixture was heated to 160°C, and water was distilled off using the water separation tube. The xylene separated from the water was returned to the reaction solution. Subsequently, 72 parts of the polyester resin (PE-1) obtained in Production Example 1, heated to 160°C, was charged and reacted at 160°C for 2 hours. The mixture was then heated at 160°C for 0.5 hours, the xylene was distilled off, and the remaining resin was removed. The removed resin was cooled to room temperature and pulverized to obtain polyesteramide resin (A6). The polyesteramide resin (A6) had a number average molecular weight (Mn) of 10,000 and an acid value of 0.3 mg KOH / g.

[0201] <Solvent> Ethanol, d-limonene, ethyl acetate, and NMP (N-methylpyrrolidone) manufactured by Tokyo Chemical Industry Co., Ltd. were used.

[0202] <Filler> CB: Carbon Black SUPER C65 manufactured by MTI Corporation.

[0203] <Receptor layer resin composition 1> Table 1 shows the substances contained in resin compositions 1 to 4 used in the odorant-receiving layer (hereinafter, receiving layer resin compositions) and the composition ratios of these substances. Resin for receiving layer: A1 70 parts by weight Filler: CB 30 parts by weight NMP: 400 parts by weight The mixture of the above-mentioned receiving layer resin, filler and NMP was stirred at 2000 rpm for 20 minutes using a centrifugal / revolutionary mixer (ARE-310 manufactured by Thinky Corporation) to obtain receiving layer resin composition 1 as a slurry.

[0204] For receiving layer resin compositions 2 to 4, which have different composition ratios of the contained substances, slurries were prepared in the same manner as for receiving layer resin composition 1, with the composition ratios shown in Table 1.

[0205] [Table 1]

[0206] <Creating sensor element E1-5> Table 2 shows the correspondence between sensor elements (E1-5) to (E-25) and the compositions of the odorant receiving layer and odorant permeation layer. An odorant receiving layer was formed on the prepared sensor substrate K-1 using a coating device equipped with a SUS metal needle nozzle (inner diameter 0.1 mmΦ, outer diameter 0.23 mm) attached to an IMAGE MASTER 350 PC Smart manufactured by Musashi Engineering Co., Ltd. An appropriate amount of receiving layer resin composition 1 was dropped and applied to the metal wiring portion. After application, the coating was dried for 3 hours in a circulating air dryer heated to 100°C.

[0207] Next, using the same coating equipment, R1-SiO 3 / 2 An appropriate amount of composition S1 represented by the formula (I) was applied to the film to the thickness shown in Table 2, and an odorant permeation layer was placed to cover the odorant receiving layer. After application, the film was dried for 3 hours in a circulating air dryer heated to 100°C. After drying, the film was cooled to room temperature to produce a sensor element (E1-5). The same procedure was repeated 10 times to produce 10 sensor elements for each sensor element.

[0208] <Fabrication of sensor elements E1-6 to E1-13, E1-17, E1-18, and E1-20> Sensor elements E1-6 to E1-13, E1-17, E1-18, and E1-20 were produced in the same manner as sensor element E1-5, except that the odorant receiving layer and odorant permeation layer had the compositions shown in Table 2.

[0209] <Fabrication of Sensor Elements E1-14 to E1-16 and E1-21 to E1-24> R1-SiO for odorant permeation layer 3 / 2 Instead of the composition S1 represented by the formula: R1-SiO for the odorant permeation layer 3 / 2 A mixture was obtained by pre-mixing 8 parts of composition S1 represented by the formula: with 2 parts each of compositions S4 to S9 represented by R2-SiO1 for the odorant permeation layer. Except for using these mixtures, sensor elements E1-14 to E1-16 and E1-21 to E1-24, which have odorant receiving layers and odorant permeation layers with the compositions shown in Table 2, were produced in the same manner as sensor element E1-5.

[0210] <Fabrication of sensor element E1-19> Sensor element E1-19 was produced in the same manner as sensor element E1-5, except that only the odorant receiving layer was formed and no odorant permeation layer was formed.

[0211] <Fabrication of sensor element E1-25> Sensor element E1-25 was produced in the same manner as sensor element E1-24, except that only the odorant receiving layer was formed and no odorant permeation layer was formed.

[0212] [Table 2]

[0213] <Construction of odor sensors 13 to 33> We created a housing equipped with a target sample receiving section with an inlet for introducing the sample (odor substance) and an aluminum block thermostatic bath for temperature control, a nitrogen gas cylinder for gas supply, a mass flow controller, and a sensor chamber. The volume of the target sample receiving section was designed to be five times the volume of the sensor chamber.

[0214] Lead wires for connecting the sensor terminals to the outside were soldered to each of the sensor elements (E1-5) to (E1-25), and 24 sensor elements (E1-5) to (E1-25) were installed in each sensor chamber. A 5V constant-voltage power supply and a 300Ω fixed resistor were connected in series to the ends of the lead wires connected to the outside of the sensor chamber for each of the sensor elements (E1-5) to (E1-25), and a voltmeter was connected to measure the voltage across both terminals of the sensor element. In this way, odor sensors 13 to 33 were constructed, each having 24 sensor elements (E1-5) to (E1-25).

[0215] <Preparation of test samples> 0.01 g of ethanol, 0.05 g of d-limonene, and 0.02 g of ethyl acetate were introduced into an Almirami gas bag (AA-10, GL Sciences) using a microsyringe, followed by 10 L of nitrogen gas. The gas bag was left at 40°C for 3 hours and then at room temperature for 9 hours to produce various organic solvent gases (1x). These gases were then diluted with nitrogen gas at the following dilution ratios: Dilution ratios: 1.5x, 2x, 2.5x, 3x, 3.5x, 4x, 4.5x, 5x, 6x, 7x, 8x, 9x, 10x, 11x, 12x, 13x, 14x, 15x, 16x, 17x.

[0216] <Examples 1-9 to 1-26, Comparative Examples 2 to 4> [Measurement of various organic solvent gases] For each of odor sensors 13-33 installed in the laboratory (temperature 23°C, humidity 40%), the temperature inside the target sample receiving section was adjusted to 30°C using an aluminum block thermostatic chamber. Then, one type of organic solvent gas, each diluted with various odorant (analyte), was introduced into the inlet of the odor sensor. Nitrogen was then flowed from the nitrogen gas supply cylinder into the target sample receiving section at a flow rate of 1 L / min using a mass flow controller for 15 seconds, and then discharged to the outside via the sensor chamber. Subsequently, nitrogen gas was flowed directly from the nitrogen gas cylinder into the sensor chamber at a flow rate of 1 L / min using a mass flow controller for 60 seconds, bypassing the target sample receiving section, and then directly discharged to the outside. This operation removed odorants adhering to the sensor element. From the start of the organic solvent gas introduction until the completion of odorant removal, the measurements of the voltmeter connected to the sensor element were recorded on a computer at a sampling rate of 100 Hz. In this way, the time-dependent changes in voltage values ​​of each of the 24 sensor elements in the odor sensor were measured. This odor measurement procedure was repeated 16 times for each odor sensor.

[0217] [Measurement of the dilution ratio of the detection limit] For each sensor element, the maximum difference ΔV between the output voltage V0 before sample introduction and the voltage V during sample introduction was calculated. This output voltage was designated Vmax. The measurement period was set to include both the voltage range before sample introduction and the maximum voltage range during sample introduction. The arithmetic mean of the voltage data for 0.1 s before and after that point was used as the measurement value. The time period for averaging could also be set to 10 times the reciprocal of the sampling rate (Hz) (i.e., 10 data points were acquired). The ratio of the standard deviation of the 10 data points measured during measurement to the output voltage V0 before sample introduction and ΔV (the number of times ΔV corresponds to the standard deviation) was calculated. When the average of 16 runs of this ratio was 3 or greater, it was determined that the sensor element was able to detect the sample at the dilution ratio used. Measurements were then repeated using samples with varying dilution ratios until the sensor element could no longer detect the sample, thereby determining the detection limit dilution ratio. Similar measurements were also performed on each sample prepared.

[0218] [Evaluation of repeatability] FIG. 13 is a graph illustrating the procedure for determining Tz, with the vertical axis representing voltage values ​​and the horizontal axis representing time. In FIG. 13, X represents the change in the measured voltage values, and T0 represents the time when the sample began to be introduced into the target sample receiving section. The method and results for evaluating repeatability will be explained below with reference to FIG. 13. Measurements were performed on sensor elements E1-5 to E1-25 using a sample diluted 1.5 times with ethanol, and the resulting voltage values ​​were plotted against time. The resulting plots were subjected to the following steps 1 to 5 to obtain Tz. 1. Calculate T1. T1 is the time when nitrogen gas starts flowing from the nitrogen gas cylinder for cleaning after the sample is introduced into the sensor chamber. 2. On a graph obtained based on the plot (for example, the graph shown in FIG. 13), a line L1 is drawn that passes through the time (T0) when sample introduction begins and touches the vertical axis at a value higher than voltage value V0. 3. As shown in "Operation A" in Figure 13, the set line L1 is asymptotically moved from the bottom of the graph X until it touches the baseline (the line that passes through the voltage value V0 and is parallel to the horizontal axis). Draw a vertical line from L1 obtained in 4.3, determine the point of intersection with the plot on graph X, and find the time (T2) corresponding to the intersection on the plot where a line segment can be drawn so that the distance between L1 and the plot is 10% of Vmax. 5.Let the difference between T2 and T1 be Tz.

[0219] As can be seen from the above, T2 indicates the time when, after a measurement is performed using a sensor element, the output voltage V rises and then drops to a value close to V0, specifically to 10% of Vmax, i.e., the time when it becomes possible to perform another measurement using the sensor element. Furthermore, Tz indicates the time from T1 to T2, i.e., the time when the output voltage V drops after reaching its maximum value Vmax and becomes possible to perform the next measurement. The time when the output voltage V starts to drop can be considered to indicate the time when the sample begins to be removed from the target sample receiving section. Therefore, Tz can also be expressed as the time from when the sample begins to be removed from the target sample receiving section until the next measurement becomes possible. From the above, it can be said that the smaller Tz is, the more quickly the sensor element can perform the next measurement after the previous measurement. Therefore, it can be said that the smaller Tz is, the more easily the sensor element has the property of removing the odorant to be measured. In other words, it can be said that it is easier to perform repeated measurements more frequently within a certain period of time. Note that when repeated measurements are performed, T1, T2, and Tz are defined for each measurement. Furthermore, if the length, diameter, and volume of the piping and sensor chamber between odor sensors change, the timing of gas switching and the timing of gas hitting the sensor element may differ, which may affect the results. For this reason, the above-mentioned Tz measurements were performed using odor sensors configured under the same conditions except for the sensor element.

[0220] [Table 3]

[0221] Comparison of Examples 1-9 and Comparative Example 2 As shown in Table 3, although the composition of the odorant receptor layer was the same, R1-SiO 3 / 2 Although there is no significant difference in Tz between Example 1-9, which has an odorant-permeable layer containing a composition having a structure represented by the formula (1), and Comparative Example 2, which does not have such a layer, the Example group shows a higher dilution ratio of each organic solvent gas. Therefore, it can be said that the sensor element corresponding to Example 1-9, which has a configuration according to the present invention, has achieved improved measurement accuracy and improved responsiveness. Furthermore, the sensor elements according to Examples 1-10 to 1-26 also showed similar trends.

[0222] Comparison of Examples 1-9 and Comparative Example 3 As shown in Table 3, the odorant receptor layer had the same composition, but the odorant permeation layer was made of R1-SiO 3 / 2 In Example 1-9, which was configured with the above composition, and Comparative Example 3, which was configured with the other composition, the Example group showed better results in terms of both the dilution ratio of each organic solvent gas and Tz. Therefore, it can be said that the sensor element according to Example 1-9, which has the configuration according to the present invention, has achieved improved measurement accuracy and improved responsiveness. Furthermore, the sensor elements according to Examples 1-10 to 1-26 also showed the same tendency as the sensor element according to Example 1-9.

[0223] Comparison of Examples 1-9 and Comparative Example 2 As shown in Table 3, although the composition of the odorant receptor layer was the same, R1-SiO 3 / 2 Although there is no significant difference in Tz between Example 1-26, which has an odorant-permeable layer containing a composition having a structure represented by the formula (1), and Comparative Example 4, which does not have such a layer, Example 1-26 shows a higher dilution ratio of each organic solvent gas. Therefore, it can be said that the sensor element corresponding to Example 1-26 having the configuration according to the present invention has achieved improved measurement accuracy and improved responsiveness. [Industrial Applicability]

[0224] The present invention is useful as an odor identification sensor for medical, gas detection, agricultural, and other industrial and daily uses. For example, farmers can use the odor identification sensor to determine the maturity of fragrant crops and manage the optimal harvest timing. Furthermore, the odor identification sensor can also be used to digitize the odors of products such as food and cosmetics, helping to improve the efficiency of product development and stabilize quality. [Explanation of symbols]

[0225] 10, 10a Estimation device 11 Measurement value acquisition unit (acquisition unit) 12 Change pattern analysis unit (analysis unit) 16 Estimation part 30 Odor Sensor 31A Multiple sensor elements (sensor element group) 31, 31b, 31c sensor elements 32 Constant voltage power supply (power supply) 33 Voltmeter (measuring instrument) 100, 100a Odor measuring device 313A, 313C 1st metal wiring 313B, 313D 2nd metal wiring 315, 315c, 315d Odorant receptor layer 317 Odor-permeable layer 50 Target sample receiving section 51 Adjustment part 60 Sensor Chamber 80 Gas supply section 91, 92, 93, 94 Body 501 1st mouth 502 2nd mouth 503 Sample inlet

Claims

1. An odorant receiving layer comprising a resin composition comprising a resin (A) and a filler (B); A first metal wiring that is in contact with at least a portion of the odorant receiving layer, and a second metal wiring that is spaced apart from the first metal wiring and in contact with at least a portion of the odorant receiving layer; an odorant permeable layer that covers at least a portion of the odorant receiving layer on the side opposite to the side in contact with the first metal wiring and the second metal wiring; Equipped with The odorant permeable layer is R1-SiO ３／２ and R2-SiO １ The composition includes at least one of the structures represented by R1 is a hydrocarbon group having 1 to 18 carbon atoms, R2 contains one or more functional groups selected from the group consisting of a hydrogen atom, an amide group, a methyl group, an alkyl group having from 1 to 12 carbon atoms, an aralkyl group having from 1 to 12 carbon atoms, an amino group, a hydroxyl group, a carboxyl group, a fluoromethyl group, a polyester group, and a polyether group; The filler is a conductive carbon material or a metal powder. A sensor element for an odor measuring device.

2. 2. The sensor element for an odor measuring device according to claim 1, wherein the odorant-permeable layer is a thin film having a thickness of 0.1 μm to 50 μm.

3. 2. A sensor element for an odor measuring device as described in claim 1, wherein the resin (A) contained in the odorant receiving layer does not contain a composition represented by -SiOn (n is 1 or more and 3 / 2 or less).

4. 2. The sensor element for an odor measuring device according to claim 1, wherein the odorant receiving layer is a thin film having a thickness of 1 μm or more and 50 μm or less.

5. 2. The sensor element for an odor measuring device according to claim 1, wherein the filler (B) is a conductive carbon material.

6. R1 includes one or more functional groups selected from the group consisting of an aliphatic hydrocarbon group and an aromatic group. A sensor element for use in the odor measuring device according to claim 1.

7. The content of the filler (B) is 10 to 50% by weight, when the total amount of the resin (A) and the filler (B) is 100% by weight. A sensor element for use in the odor measuring device according to claim 1.

8. A sensor element according to any one of claims 1 to 7, Odor measuring device.

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