WO2023008496A1

WO2023008496A1 - Polymer composition, substance adsorption film, and method for manufacturing sensor element

Info

Publication number: WO2023008496A1
Application number: PCT/JP2022/029010
Authority: WO
Inventors: 洋海塩; 裕一影山; 祥司品村; 貴文松尾
Original assignee: 味の素株式会社
Priority date: 2021-07-28
Filing date: 2022-07-27
Publication date: 2023-02-02
Also published as: JPWO2023008496A1

Abstract

Provided is a polymer composition for forming a substance adsorption film for a sensor element, the sensor element comprising a substance adsorption film and a transducer part on the surface of which the substance adsorption film is provided and whereby a change in a physical parameter that occurs as a result of adsorption of a substance to the substance adsorption film can be detected, wherein: the polymer composition includes a polymer compound, a crosslinking agent, and a solvent; the crosslinking agent can react with the polymer compound or react with itself to form a crosslinked structure; and the gel fraction when an evaluation sample obtained by leaving the polymer composition for 60 minutes at 150°C is immersed in the solvent is 0.1% or greater.

Description

Polymer composition, substance adsorption film, and method for producing sensor element

TECHNICAL FIELD The present invention relates to a method for manufacturing a sensor element capable of detecting changes in physical parameters due to substance adsorption; a substance adsorption film provided on the sensor device; and a polymer composition for use in forming the substance adsorption film. .

Gas sensors such as odor sensors are used for various purposes. For example, an odor sensor is known for detecting odors generated by rotting food and controlling the quality of food in a refrigerator. Odor sensors are also known, for example, for use in quality control and sensory evaluation of foods and fragrances.

A piezoelectric sensor having a piezoelectric element such as a crystal oscillator or a surface acoustic wave element is known as a gas sensor such as an odor sensor. These piezoelectric sensors have a substance-adsorbing film, and detect the odorant by detecting the mass change due to the odorant being adsorbed on the substance-adsorbing film (Patent Document 1).

WO2017/085939

A sensor element provided in a sensor device such as a gas sensor may have many types of substance adsorption films in order to detect many types of substances. Each of these substance adsorption films can contain polymer compounds having different properties such as chemical properties and physical properties. Since the polymer compounds adsorb substances according to their properties, the substance adsorption films can adsorb different types of substances, so that the sensor element can detect a wide variety of substances.

The sensor devices such as the gas sensors described above are sometimes used in environments that can reach high temperatures. For example, sensor devices may be exposed to high temperatures in environments such as vehicles, factories, and kitchens. However, the substance adsorption film of the sensor element included in the sensor device may be inferior in heat resistance. For example, when many kinds of substance adsorption films are provided on a sensor element for detecting many kinds of substances, it is required to use polymer compounds with poor heat resistance in some or all of the substance adsorption films. These substance adsorption films may be inferior in heat resistance.

If the substance adsorption film has poor heat resistance, the substance adsorption film may easily fluidize in a high temperature environment. A fluidized substance-adsorbing film can be easily deformed by gravity and its area can change. Such changes can cause increased detection errors. Thus, when a conventional sensor device is exposed to high temperatures, it can be difficult to accurately detect when the temperature subsequently returns to room temperature.

The present invention has been invented in view of the above problems, and provides a polymer composition capable of producing a substance adsorption film having improved heat resistance while maintaining substance adsorption properties; An object of the present invention is to provide an improved substance-adsorbing film; and a method for manufacturing a sensor element having the substance-adsorbing film.

The inventors have made extensive studies to solve the above problems. As a result, the present inventors have found that the above problems can be solved by introducing a crosslinked structure with an appropriate crosslink density represented by the gel fraction into the material adsorption layer, and completed the present invention.
That is, the present invention includes the following.

[1] Formation of the substance adsorption film of a sensor element comprising a substance adsorption film, and a transducer unit having the substance adsorption film on its surface and capable of detecting a change in physical parameter caused by adsorption of a substance to the substance adsorption film. A polymeric composition for
the polymer composition comprises a polymer compound, a cross-linking agent, and a solvent;
The cross-linking agent can react with the polymer compound or react with each other to form a cross-linked structure;
A polymer composition, wherein a proportion of a portion that becomes insoluble when an evaluation sample obtained by standing the polymer composition at 150° C. for 60 minutes is immersed in the solvent is 0.10% or more.
[2] The polymer composition of [1], wherein the cross-linking agent has an isocyanate group that may be blocked.
[3] The polymer composition according to [1] or [2], wherein the polymer compound has a hydroxyl group.
[4] The polymer composition according to any one of [1] to [3], wherein the polymer compound has an amino group.
[5] A substance adsorption film for a sensor element comprising: a substance adsorption film; and a transducer unit having the substance adsorption film on its surface and capable of detecting changes in physical parameters caused by adsorption of substances to the substance adsorption film. hand;
the substance adsorption film contains a polymer compound that may be crosslinked;
The proportion of the portion that becomes insoluble when the substance adsorption film is immersed in at least one solvent selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, tetralin and methyl benzoate is 0.10% or more. is a substance adsorption film.
[6] The substance adsorption film according to [5], wherein the substance adsorption film contains the crosslinked polymer compound.
[7] The substance adsorption film according to [5] or [6], further comprising a polymer having a crosslinked structure.
[8] When the substance adsorption film is adhered to an aluminum surface and left to stand at 100° C. for 30 minutes with the aluminum surface parallel to the vertical direction, the substance adsorption film maintains a planar shape; The substance adsorption film according to any one of [7].
[9] A step of forming a layer of the polymer composition according to any one of [1] to [4] on the surface of a transducer section capable of detecting changes in physical parameters;
and a step of causing a cross-linking reaction with a cross-linking agent contained in the polymer composition layer.

According to the present invention, a polymer composition capable of producing a substance adsorption film having improved heat resistance while maintaining substance adsorption properties; a substance adsorption film having improved heat resistance while maintaining substance adsorption properties; can provide a method for manufacturing a sensor element comprising a substance adsorption film of

FIG. 1 is a side view schematically showing a sensor element according to one embodiment of the invention. FIG. 2 is a schematic diagram schematically showing a sensor device as an example. FIG. 3 is a photograph of the substance adsorption films of Example I-1 and Comparative Example I-1. FIG. 4 is a photograph of the substance adsorption films of Example I-2 and Comparative Example I-2. FIG. 5 is a photograph of the substance adsorption films of Example I-3 and Comparative Example I-3. FIG. 6 is a photograph of the substance adsorption films of Example I-4 and Comparative Example I-4. FIG. 7 is a graph showing the amount of response when water was detected as an odorant sample using the odor sensor element before heating in Examples II-1 to II-4 and Comparative Examples II-1 to II-4. be. FIG. 8 is a graph showing the amount of response when water was detected as an odorant sample using the odor sensor element after heating in Examples II-1 to II-4 and Comparative Examples II-1 to II-4. be. FIG. 9 is a graph showing the results of principal component analysis of the response amounts measured in Examples II-1 to II-4 and Comparative Examples II-1 to II-7. FIG. 10 is a photograph showing an image of a polymer composition layer before drying and an image of a substance adsorption film obtained by drying the polymer composition layer in Example III-1. FIG. 11 is a photograph showing an image of a polymer composition layer before drying and an image of a substance adsorption film obtained by drying the polymer composition layer in Example III-2. FIG. 12 is a photograph showing an image of a polymer composition layer before drying and an image of a substance adsorption film obtained by drying the polymer composition layer in Example III-3.

Hereinafter, the present invention will be described in detail by showing embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be arbitrarily modified without departing from the scope of the claims of the present invention.

[1. Overview of polymer composition]
A polymer composition according to one embodiment of the present invention includes a combination of a polymer compound, a cross-linking agent other than the polymer compound, and a solvent. The cross-linking agent can react with the polymer compound or react with each other to form a cross-linked structure. Furthermore, the percentage of the portion that becomes insoluble when an evaluation sample obtained by standing the polymer composition at a specific temperature for a specific time is immersed in a solvent is within a specific range. Hereinafter, the ratio of the portion that becomes insoluble when an evaluation sample is immersed in a solvent is sometimes referred to as "gel fraction".

The polymer composition is a sensor element comprising a substance-adsorbing film and a transducer unit having the substance-adsorbing film on its surface and capable of detecting a change in a physical parameter caused by adsorption of a substance to the substance-adsorbing film. It is used to form a substance adsorption film. The term "adsorption" includes not only physical adsorption but also adsorption by chemical bonding or biochemical action, unless otherwise specified.

Generally, polymer compounds have the ability to form a film, so a polymer composition can form a substance adsorption film. A substance adsorption film manufactured from the polymer composition according to the present embodiment can have high heat resistance. Specifically, the substance adsorption film can suppress fluidization in a high temperature environment. Therefore, since deformation due to external forces such as gravity and inertial force can be suppressed, change in the area of the substance adsorption film can be suppressed. Therefore, the substance-adsorbing film can detect substances (such as odorants or gas molecules) even after exposure to high temperatures, as well as before exposure to high temperatures.

The improvement in heat resistance as described above can be achieved by forming an appropriate crosslinked structure in the substance adsorption film. For example, the substance adsorption film usually contains a polymer compound contained in the polymer composition. may be formed to form a crosslinked structure. Further, for example, the substance adsorption film obtained from the polymer composition according to the present embodiment may contain a polymer having a crosslinked structure as a polymer other than the polymer compound. A polymer having a crosslinked structure different from that of a polymer compound is hereinafter sometimes referred to as a "crosslinked polymer". At this time, the crosslink density of the crosslinked structure formed by these crosslinked polymer compounds, crosslinked polymers, or combinations thereof can be represented by the gel fraction. By including a cross-linked structure having a cross-linking density within a specific range of the gel fraction in the substance adsorption film, fluidization of the substance adsorption film due to heat is suppressed, and as a result, high heat resistance is achieved. can be done.

In addition, the substance adsorption film obtained from the polymer composition according to the present embodiment can exhibit substance adsorption properties comparable to those of conventional substance adsorption films that do not contain a crosslinked structure. Therefore, it is possible to reduce the change in the substance adsorption properties due to the introduction of the crosslinked structure for improving the heat resistance. Therefore, according to the polymer composition, it is possible to obtain a substance adsorption film having improved heat resistance while maintaining substance adsorption properties. The conventional substance adsorption film specifically refers to a conventional substance adsorption film that contains the same polymer compound as that contained in the polymer composition according to the present embodiment, but does not contain a crosslinked structure.

Furthermore, the polymer composition according to the present embodiment preferably has excellent dimensional retention in the process of manufacturing the substance adsorption film.

[2. Polymer compound]
As the polymer compound, an inorganic compound may be used, but an organic compound is preferably used. As the polymer compound, a highly regular polymer compound having appropriate repeating units is preferable. When such a polymer compound is used, it is easy to obtain a substance-adsorbing film capable of appropriately detecting a substance to be detected by a sensor element. A substance to be detected by the sensor element is hereinafter sometimes referred to as a "target substance".

Normally, in detection using a sensor element equipped with a substance adsorption film, the substance adsorbed to the substance adsorption film is detected. Therefore, it is preferable to select the specific type of polymer compound according to the target substance. Specific examples of preferred polymer compounds include phenoxy resin, phenol resin, acrylic resin, polyvinyl acetate, polyvinyl alcohol, polystyrene, imide resin, urethane resin, cellulose polymer, modified cellulose, vinylpyridine polymer, polyacrylonitrile, polyvinyl acetate, Examples include polysulfone, cycloolefin polymer, polyvinylpyrrolidone, polyphenylene ether, polyphenylene sulfide, silicone resin, polybutadiene, and copolymers thereof. Preferred copolymers include, for example, polyallylamine-polycaprolactone copolymers.

The polymer compound may have an appropriate functional group from the viewpoint of adjusting the ease of adsorption of the target substance and from the viewpoint of advancing the cross-linking reaction by the cross-linking agent. Examples of the functional group that the polymer compound preferably has include a hydroxyl group. A polymer compound having a hydroxyl group can adjust the ease with which a specific type of target substance is adsorbed, or can undergo a cross-linking reaction with an appropriate type of cross-linking agent.

The amount of functional groups in a polymer compound having functional groups such as hydroxyl groups can be represented by an acid value. In one example, the acid value of the polymer compound is preferably 1 mgKOH/g or more, more preferably 5 mgKOH/g or more, particularly preferably 10 mgKOH/g or more, preferably 50 mgKOH/g or less, more preferably 30 mgKOH/g or less. , particularly preferably 25 mgKOH/g or less.

In particular, when the polymer compound has hydroxyl groups, it is preferable that the polymer compound contains the number of hydroxyl groups within a specific range per unit mass. The specific range of the number of hydroxyl groups per unit mass of the polymer compound is preferably 1.0×10 ⁻⁵ mol/g or more, more preferably 2.0×10 ⁻⁵ mol/g or more, and particularly preferably 3.0 × 10 ^-5 mol/g or more, preferably 1.0 × 10 ^-1 mol/g or less, more preferably 3.0 × 10 ^-2 mol/g or less, particularly preferably 2.0 × 10 ⁻² mol/g or less. When the polymer composition contains only one type of polymer compound, the number of hydroxyl groups per unit mass of the polymer compound is preferably within the above range. Moreover, when the polymer composition contains two or more types of polymer compounds, the weighted average of the number of hydroxyl groups per unit mass of those polymer compounds is preferably within the above range. The aforementioned weighted average represents a weighted average based on mass. Therefore, for example, W1 parts by mass of the first polymer compound having A1 number of hydroxyl groups per unit mass and W2 parts by mass of the second polymer compound having A2 number of hydroxyl groups per unit mass are combined. When used, the weighted average of the number of hydroxyl groups "A1×{W1/(W1+W2)}+A2×{W2/(W1+W2)}" is preferably within the above range.

The number of hydroxyl groups per unit mass of the polymer compound can be calculated as the reciprocal of the hydroxyl equivalent of the polymer compound. Moreover, the hydroxyl group equivalent of the polymer compound represents the mass of the polymer compound having one equivalent of hydroxyl group. The hydroxyl group equivalent of a polymer compound can be determined by "hydroxyl group equivalent=56100/hydroxyl group value (mgKOH/g)".

Another functional group that the polymer compound preferably has is, for example, an amino group. A polymer compound having an amino group can adjust the ease with which a specific type of target substance is adsorbed, or can undergo a cross-linking reaction with an appropriate type of cross-linking agent.

The amount of the functional group in a polymer compound having a functional group such as an amino group can be represented by an amine value. In one example, the amine value of the polymer compound is preferably 0.1 mgKOH/g or more, more preferably 1 mgKOH/g or more, particularly preferably 5 mgKOH/g or more, preferably 100 mgKOH/g or less, more preferably 50 mgKOH/g. g or less, particularly preferably 20 mgKOH/g or less.

Since the substance adsorption film that is formed is usually solid at room temperature, the polymer compound is also preferably solid at room temperature.

The weight average molecular weight of the polymer compound is preferably 1,000 or more, more preferably 2,000 or more, particularly preferably 3,000 or more, and preferably 1,000,000 or less, more preferably 500,000 or less, and particularly preferably 300,000 or less. When a polymer compound having a weight-average molecular weight within such a range is used, it is easy to obtain a substance-adsorbing film capable of appropriately detecting the target substance.
The weight-average molecular weight of the polymer compound can be measured as a polystyrene-equivalent value by a gel permeation chromatography (GPC) method.

In the polymer composition, the polymer compound may be dispersed in the solvent, but from the viewpoint of prolonging the pot life of the polymer composition, it is preferably dissolved in the solvent.

The amount of the polymer compound relative to 100% by mass of the polymer composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 0.7% by mass or more, and particularly preferably 1% by mass. It is preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, and particularly preferably 30% by mass or less. When the polymer compound is used in an amount within the above range, the viscosity of the polymer composition can be kept within an appropriate range, so that the handleability of the polymer composition can be improved.

The amount of the polymer compound relative to 100% by mass of the solid content of the polymer composition is preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, and preferably 99% by mass or less. More preferably 98% by mass or less, particularly preferably 97% by mass or less. The solid content of the polymer composition represents components other than the solvent contained in the polymer composition. When the polymer compound is used in an amount within the above range, the effect of the present invention can be obtained remarkably.

[3. Crosslinking agent]
As the cross-linking agent, a compound capable of forming a cross-linked structure in the substance adsorption film can be used. Generally, a compound that can form a crosslinked structure by causing a crosslinking reaction when the polymer composition is allowed to stand under appropriate reaction conditions (for example, 150° C. for 60 minutes) is used as the crosslinking agent. As the cross-linking agent, a compound capable of forming a cross-linked structure by causing a cross-linking reaction with a polymer compound may be used, or a compound capable of forming a cross-linked structure by causing a cross-linking reaction between cross-linking agents may be used. They may be used in combination.

As a cross-linking agent capable of forming a cross-linked structure by causing a cross-linking reaction with a polymer compound, a compound having a cross-linkable group capable of forming a bond by reacting with a functional group possessed by the polymer compound can be used. Usually, this cross-linking agent has a plurality of cross-linkable groups in one molecule, and these cross-linkable groups react with the functional groups of the polymer compound, thereby cross-linking the molecules of the polymer compound. can be formed.

The specific type of crosslinkable group that can react with the functional group of the polymer compound is preferably selected according to the type of the functional group. Specific examples of preferred crosslinkable groups include isocyanate groups (-N=C=O), epoxy groups, acid anhydride groups, hydroxyl groups, amino groups, aldehyde groups, carbonyl groups, carboxy groups, azo groups, nitro groups, and thiols. group, sulfone group, halogen group, ester group, amide group and the like. Moreover, these crosslinkable groups may be blocked. For example, isocyanate groups may be blocked. The blocked isocyanate groups are inactivated at room temperature, but when exposed to heat, the blocking agent dissociates and the isocyanate groups are regenerated, which can cause cross-linking reactions with the functional groups of the polymer compound. can.

Examples of preferred cross-linking agents include blocked isocyanates. A blocked isocyanate as a cross-linking agent usually has a plurality of blocked isocyanate groups in one molecule. A blocked isocyanate can be produced, for example, by reacting an isocyanate compound having multiple isocyanate groups in one molecule with a blocking agent.

Examples of isocyanate compounds include aliphatic isocyanates such as 1,6-hexane diisocyanate, 1,3,6-hexamethylene triisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate; 1,4-cyclohexane diisocyanate, 4 , 4′-dicyclohexylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate and other alicyclic isocyanates; 4,4′-diphenylmethane diisocyanate, 2, 4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, 1,4-phenylene diisocyanate, 2,6-phenylene diisocyanate, 1,5-naphthalene diisocyanate, 4,4 - aromatic isocyanates such as diphenyl diisocyanate; An isocyanate compound may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of blocking agents include alcohol compounds, phenol compounds, ε-caprolactam, oxime compounds, active methylene compounds, mercaptan compounds, amine compounds, imide compounds, acid amide compounds, imidazole compounds, urea compounds, carbamate compounds, and imine compounds. , and sulfite compounds. Among them, a thermally dissociable blocking agent that can be dissociated by heat is preferable as the blocking agent. Examples of thermally dissociable blocking agents include lactam compounds such as γ-butyrolactam, ε-caprolactam, γ-valerolactam, propiolactam; Oxime compounds such as acetoxime, diacetyl monoxime, benzophenone oxime, cyclohexanone oxime; monocyclic phenol compounds such as phenol, cresol, catechol and nitrophenol; polycyclic phenol compounds such as 1-naphthol; methyl alcohol, ethyl alcohol, isopropyl alcohol , tert-butyl alcohol, trimethylolpropane, 2-ethylhexyl alcohol and other alcohol compounds; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether and other ether compounds; malonic acid alkyl esters, malonic acid dialkyl esters, aceto active methylene compounds such as acetic acid alkyl esters and acetylacetone; One type of blocking agent may be used alone, or two or more types may be used in combination.

A commercially available product may be used as the blocked isocyanate. Examples of commercially available blocked isocyanates include hexamethylene diisocyanate-based blocked isocyanates (e.g., Asahi Kasei Duranate SBN-70D, SBB-70P, SBF-70E, TPA-B80E, 17B-60P, MF-B60B, E402-B80B , MF-K60B, and WM44-L70G; Takenate B-882N manufactured by Mitsui Chemicals; 7960, 7961, 7982, 7991, and 7992 manufactured by Baxenden, etc.), tolylene diisocyanate-based blocked isocyanate (for example, manufactured by Mitsui Chemicals) Takenate B-830, etc.), 4,4′-diphenylmethane diisocyanate-based blocked isocyanate (for example, Takenate B-815N manufactured by Mitsui Chemicals; Bronate PMD-OA01 and PMD-MA01 manufactured by Taiei Sangyo Co., Ltd.), 1 ,3-bis(isocyanatomethyl)cyclohexane-based blocked isocyanate (e.g., Takenate B-846N manufactured by Mitsui Chemicals; Coronate BI-301, 2507, and 2554 manufactured by Tosoh Corporation), isophorone diisocyanate-based blocked isocyanate (e.g., Baxenden 7950, 7951, and 7990 manufactured by the company). Block isocyanate may be used individually by 1 type, and may be used in combination of 2 or more types.

Another example of a preferable cross-linking agent is an epoxy resin. An epoxy resin as a cross-linking agent usually has a plurality of epoxy groups in one molecule. Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, and naphthol type epoxy resin. , naphthalene type epoxy resin, naphthylene ether type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, fluorene skeleton type epoxy resin, dicyclopentadiene type epoxy resin, anthracene type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanediene Examples include methanol-type epoxy resins, trimethylol-type epoxy resins, and halogenated epoxy resins.

A commercially available product may be used as the epoxy resin. Examples of commercially available epoxy resins include "ZX-1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical & Materials Co., Ltd., and the like. One type of epoxy resin may be used alone, or two or more types may be used in combination.

Another example of a preferable cross-linking agent is an acid anhydride compound. An acid anhydride compound as a cross-linking agent usually has one or more carboxylic acid anhydride groups (--CO--O--CO--) in one molecule. Examples of acid anhydride compounds include phthalic anhydride, pyromellitic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, and 2,3,6,7-naphthalenetetracarboxylic dianhydride. 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3 Aromatic acids such as ',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, and methylene-4,4'-diphthalic dianhydride Anhydride compounds; tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl Aliphatic acid anhydride compounds such as succinic anhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride; styrene-maleic anhydride copolymer, (meth ) maleic anhydride polymer compounds such as alkyl acrylate-styrene-maleic anhydride copolymer;

A commercially available product may be used as the acid anhydride compound. Examples of commercially available acid anhydride compounds include styrene-maleic anhydride copolymer "EF80" manufactured by Cray Valley. The acid anhydride compound may be used singly or in combination of two or more.

When using a cross-linking agent capable of forming a cross-linked structure by causing a cross-linking reaction with a polymer compound, it is preferable to set the amount ratio between the cross-linking agent and the polymer compound so as to obtain a gel fraction within a specific range. . Usually, it is preferable to use an amount of cross-linking agent containing cross-linkable groups that can react with most of the functional groups of the polymer compound, and an amount of cross-linkable groups that can react with all the functional groups of the polymer compound. It is more preferable to use an amount of cross-linking agent containing

Therefore, the number N _B of crosslinkable groups of the cross-linking agent contained in the polymer composition is preferably 0.001× the number N _F of functional groups possessed by the polymer compound contained in the polymer composition. N _F or more, more preferably 0.01 x N _F or more, still more preferably 0.02 x N _F or more, particularly preferably 0.05 x N _F or more, preferably 100 x N _F or less, more preferably It is 50×N _F or less, more preferably 20×N _F or less. For example, when one crosslinkable group of the crosslinker reacts with one functional group of the polymer compound, the number _NB of crosslinkable groups of the crosslinker is preferably within the above range.

The number N _F of functional groups possessed by the polymer compound contained in the polymer composition is the sum of all the values obtained by dividing the mass of the polymer compound contained in the polymer composition by the functional group equivalent of the polymer compound. represents For example, the number of hydroxyl groups in a polymer compound can be determined by dividing the mass of the polymer compound by the hydroxyl equivalent weight of the polymer compound.

Further, the number _NB of crosslinkable groups possessed by the crosslinker contained in the polymer composition is obtained by dividing the mass of the crosslinker contained in the polymer composition by the crosslinkable group equivalent of the crosslinker, and totaling all the values. represents a value. For example, the number of epoxy groups in a cross-linking agent can be obtained by dividing the mass of the cross-linking agent by the epoxy group equivalent weight of the cross-linking agent. In particular, for blocked isocyanate among cross-linking agents, the cross-linkable group equivalent is not disclosed by the manufacturer, but the isocyanate group content (NCO rate) may be disclosed. In this case, the isocyanate group equivalent is usually obtained by dividing the isocyanate group formula weight (that is, 42) by the isocyanate group content, and that isocyanate group equivalent can be used as the crosslinkable group equivalent of the blocked isocyanate.

As a cross-linking agent capable of forming a cross-linked structure by causing a cross-linking reaction between cross-linking agents, a compound having a cross-linking group capable of forming a bond by reacting the cross-linking groups possessed by the cross-linking agent can be used. Usually, this cross-linking agent has a plurality of cross-linking groups in one molecule, and the cross-linking groups can react with each other to form a cross-linking structure that bridges the molecules of the cross-linking agent. A crosslinked polymer having a structure can be obtained. The crosslinked polymer thus obtained preferably does not have the same kind of functional groups as those of the polymer compound.

Examples of crosslinkable groups that can form a crosslinked structure by reacting with each other include radically polymerizable unsaturated groups. A radically polymerizable unsaturated group typically contains a carbon-carbon unsaturated bond and is capable of undergoing a radical polymerization reaction. The carbon-carbon unsaturated bond that the radically polymerizable unsaturated group may contain is usually a non-aromatic unsaturated bond, such as a carbon-carbon double bond and a carbon-carbon triple bond. Examples of radically polymerizable unsaturated groups include maleimide groups, vinyl groups, allyl groups, styryl groups, vinylphenyl groups, (meth)acryloyl groups, fumaroyl groups, and maleoyl groups. The term "(meth)acryloyl group" includes acryloyl groups, methacryloyl groups, and combinations thereof, unless otherwise specified. Among them, a (meth)acryloyl group is preferred.

Examples of cross-linking agents containing (meth)acryloyl groups include (meth)acrylic resins. A (meth)acrylic resin as a cross-linking agent usually has a plurality of (meth)acryloyl groups in one molecule. A commercially available product may be used as the (meth)acrylic resin. Commercially available (meth)acrylic resins include, for example, “A-DOG” and “A-DCP” (manufactured by Shin-Nakamura Chemical Co., Ltd.); “NPDGA”, “FM-400”, “R-687”, “THE -330”, “PET-30”, “DPHA” (all manufactured by Nippon Kayaku Co., Ltd.); The (meth)acrylic resins may be used singly or in combination of two or more.

One type of cross-linking agent may be used alone, or two or more types may be used in combination.

The cross-linking agent preferably has a molecular weight smaller than the weight average molecular weight of the polymer compound. Specific molecular weight of the cross-linking agent is preferably 200 or more, more preferably 250 or more, particularly preferably 300 or more, preferably less than 5000, more preferably less than 3000, still more preferably less than 1000, particularly preferably less than 500 is. When the molecular weight of the cross-linking agent is at least the above lower limit, a stable cross-linked structure can be formed between the polymer compound and the cross-linking agent. Further, when the molecular weight of the cross-linking agent is less than the above upper limit, the influence of the cross-linking agent on the substance adsorption properties of the polymer compound can be effectively reduced, so that a substance adsorption film capable of appropriately detecting the target substance can be obtained. Cheap.

In the polymer composition, the cross-linking agent may be dispersed in the solvent, but from the viewpoint of prolonging the pot life of the polymer composition, it is preferably dissolved in the solvent.

The amount of the cross-linking agent relative to 100% by mass of the polymer composition is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, particularly preferably 0.4% by mass or more, and preferably 20% by mass. Below, more preferably 10% by mass or less, particularly preferably 5% by mass or less. When the amount of the polymer compound is used as described above, the viscosity of the polymer composition can be kept within an appropriate range, so that the handleability of the polymer composition can be improved.

The amount of the cross-linking agent relative to 100% by mass of the solid content of the polymer composition is preferably 1% by mass or more, more preferably 2% by mass or more, more preferably 3% by mass or more, and preferably 50% by mass or less. It is preferably 30% by mass or less, particularly preferably 20% by mass or less. When the amount of the cross-linking agent within the above range is used, the effect of the present invention can be obtained remarkably.

The amount of the cross-linking agent with respect to 100% by mass of the polymer compound is preferably 2% by mass or more, more preferably 4% by mass or more, particularly preferably 5% by mass or more, preferably 100% by mass or less, more preferably 50% by mass. % or less, particularly preferably 30 mass % or less. When the amount of the cross-linking agent within the above range is used, the effect of the present invention can be obtained remarkably.

[4. solvent]
As the solvent, a compound that is liquid at normal temperature and does not react with the polymer compound and the cross-linking agent can be used. As this solvent, an inorganic solvent such as water may be used, or an organic solvent may be used. Among them, it is preferable to use an organic solvent as the solvent. Preferred organic solvents include, for example, n-heptanol, dimethylsulfoxide, decahydronaphthalene, methyl benzoate, N-methylpyrrolidone, γ-butyrolactone, 1,2,3,4-tetrahydronaphthalene (also known as tetralin), carbitol acetate. , 1,3-dimethyl-2-imidazolidinone, butyl carbitol, propyl benzoate, diethylene glycol, methyl 4-tert-butylbenzoate, butyl carbitol acetate, 1-butanol, 2-pentanol, methyl cellosolve, propylene Glycol-1-monomethyl ether-2-acetate, ethyl lactate, methyl amyl ketone, cyclohexanone, dimethylacetamide, mesitylene, and the like. One type of solvent may be used alone, or two or more types may be used in combination.

The amount of solvent is preferably set so that the concentration of solids in the polymer composition falls within a specific range. The solid content concentration of the polymer composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more, and particularly preferably 100% by mass of the polymer composition. It is 4% by mass or more, preferably 90% by mass or less, more preferably 50% by mass or less, still more preferably 45% by mass or less, and particularly preferably 30% by mass or less.

[5. optional component]
The polymer composition may further contain optional components in combination with the polymer compound, cross-linking agent and solvent described above. One type of optional component may be used alone, or two or more types may be used in combination at any ratio.

Optional components include, for example, catalysts that can promote the cross-linking reaction of the cross-linking agent. A specific example of the catalyst is an epoxy curing catalyst capable of promoting the cross-linking reaction of the epoxy resin used as the cross-linking agent. Epoxy curing catalysts include, for example, imidazole catalysts. A commercially available product may be used as the catalyst. Commercially available catalysts include, for example, imidazole-based catalysts such as "2E4MZ" manufactured by Shikoku Kasei Co., Ltd. One type of catalyst may be used alone, or two or more types may be used in combination.

Another optional component includes, for example, a polymerization initiator. When using a polymerization initiator, the reaction of the cross-linking agent having a radically polymerizable unsaturated group can be promoted. Examples of the polymerization initiator include radical polymerization initiators such as peroxide-based radical polymerization initiators and azo-based radical polymerization initiators. A commercially available product may be used as the polymerization initiator. Examples of commercially available polymerization initiators include peroxide-based radical polymerization initiators such as “Perhexa HC” manufactured by NOF Corporation. One polymerization initiator may be used alone, or two or more may be used in combination.

[6. Properties of polymer composition]
When the polymer composition according to one embodiment of the present invention is left to stand at 150 ° C. for 60 minutes to obtain an evaluation sample, the evaluation sample has a gel fraction in a specific range. have. Specifically, the specific range of the gel fraction is usually 0.10% or more, preferably 0.20% or more, and particularly preferably 0.25% or more. When the gel fraction is equal to or higher than the lower limit, it is possible to obtain a substance adsorption film having improved heat resistance while maintaining substance adsorption properties. The upper limit of the gel fraction is preferably 10.0% or less, more preferably 5.0% or less, and particularly preferably 3.0% or less, from the viewpoint of further stably maintaining the substance adsorption properties of the substance adsorption film. be.

The gel fraction of the evaluation sample represents the proportion of the portion that becomes insoluble when the evaluation sample is immersed in the solvent contained in the polymer composition. Specifically, the gel fraction of the evaluation sample can be measured by the following method.
The polymer composition is allowed to stand at 150° C. for 60 minutes to prepare an evaluation sample, and the weight W (A) of the evaluation sample is measured. The evaluation sample is then immersed in the same type of solvent that the polymer composition contained at room temperature (23° C.) for 24 hours. The immersion usually dissolves or swells the evaluation sample. The immersed evaluation sample is subjected to suction filtration, washed with a solvent, and then washed with acetone to obtain an insoluble matter (gel component). The weight W(B) of this insoluble matter is weighed, and the gel fraction is calculated by the following formula (M1).
[Gel fraction] (%) = W (B) / W (A) x 100 (M1)

The gel fraction of the evaluation sample can correspond to the gel fraction of the substance adsorption film obtained from the polymer composition. Moreover, the gel fraction has a correlation with the crosslink density of the crosslinked structure formed by the crosslink reaction of the crosslinker. Therefore, the gel fraction of the evaluation sample can represent the crosslink density of the crosslinked structure formed in the substance adsorption film obtained from the polymer composition. In general, the higher the gel fraction of the evaluation sample, the higher the crosslink density, which means that the fluidization of the substance adsorption film due to heat can be effectively suppressed by the crosslink structure. Further, according to the findings of the present inventors, even when the crosslinked structure is formed as described above, the change in the substance adsorption characteristics of the substance adsorption film due to the crosslinked structure is small. Therefore, according to the polymer composition from which an evaluation sample having a gel fraction within the specific range can be obtained, it is possible to realize a substance adsorption film with improved heat resistance while maintaining substance adsorption properties.

The gel fraction can be adjusted by appropriately adjusting factors such as the type and concentration of the polymer compound, the type and concentration of the cross-linking agent, and the amount of the cross-linking agent relative to the polymer compound. Further, the polymer composition may contain a catalyst within a range that does not affect the substance adsorption properties of the polymer compound, thereby promoting the cross-linking reaction to a desired degree and adjusting the gel fraction.

The viscosity of the polymer composition at 25° C. is preferably 1 mPa·sec or more, more preferably 2 mPa·sec or more, preferably 8000 mPa·sec or less, more preferably 3000 mPa·sec or less, and particularly preferably 1000 mPa·sec or less. is. The viscosity of the polymer composition can be measured using an E-type viscometer ("RE-85U" manufactured by Toki Sangyo Co., Ltd., 1 ° 24 × R24 cone) at 0 mPa · sec or more and less than 500 mPa · sec, and 500 mPa · sec or more. At 8000 mPa·sec or less, it can be measured with an E-type viscometer (“RE-80U” 3°×R9.7 cone manufactured by Toki Sangyo Co., Ltd.).

[7. Method for producing polymer composition]
A polymer composition can be produced by mixing, for example, a polymer compound, a cross-linking agent, a solvent, and optionally optional components. The order of mixing each component is arbitrary. Moreover, in order to promote the dissolution or dispersion of the polymer compound, the cross-linking agent and optional components in the solvent, arbitrary treatments such as stirring and heat treatment may be applied.

[8. Substance adsorption film]
A substance adsorption film according to an embodiment of the present invention comprises a substance adsorption film, and a transducer unit having the substance adsorption film on its surface and capable of detecting changes in physical parameters caused by adsorption of a substance to the substance adsorption film. It is a substance adsorption film for sensor elements. This substance adsorption film contains a polymer compound that may be crosslinked.

As a first example, the substance-adsorbing membrane comprises a cross-linked polymeric compound. A crosslinked structure is formed in the substance adsorption film by this crosslinked polymer compound.
As a second example, the substance adsorption film further contains a crosslinked polymer (that is, a polymer having a crosslinked structure) in combination with the polymer compound. In this second example, the polymeric compound may or may not be crosslinked.

In both of these first and second examples, a crosslinked structure is formed in the substance adsorption film. Therefore, the substance adsorption film can have a specific range of gel fraction depending on the crosslink density of the crosslink structure. The gel fraction of the substance adsorption film according to this embodiment is within a specific range. Specifically, the specific range of the gel fraction of the substance adsorption film can be the same as the specific range of the gel fraction of the polymer composition evaluation sample described in the section on the polymer composition.

The gel fraction of the substance adsorption film is the portion that becomes insoluble when the substance adsorption film is immersed in at least one solvent selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, tetralin and methyl benzoate. represents the ratio of That is, when the substance adsorption film is immersed in at least one solvent selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, tetralin and methyl benzoate, the specific A range of gel fractions can be obtained. Specifically, the gel fraction of the substance adsorption film can be measured by the following method.
A weight w (A) of the substance adsorption film is measured. After that, the substance adsorption film is immersed in a solvent (at least one solvent selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, tetralin and methyl benzoate) at room temperature (23° C.) for 24 hours. Immersion usually dissolves or swells the substance adsorption film. The immersed substance-adsorbing membrane is subjected to suction filtration, washed with a solvent, and then washed with acetone to obtain an insoluble matter (gel component). The weight w(B) of this insoluble matter is weighed, and the gel fraction is calculated by the following formula (M2).
[Gel fraction] (%) = w(B)/w(A) x 100 (M2)

The gel fraction has a correlation with the crosslink density of the crosslinked structure contained in the substance adsorption film. In general, the higher the gel fraction, the higher the crosslink density, which means that the fluidization of the substance adsorption film due to heat can be effectively suppressed by the crosslink structure. Furthermore, according to the findings of the present inventors, even when the crosslinked structure is formed as described above, the change in the substance adsorption characteristics of the substance adsorption film due to the crosslinked structure is small. Therefore, according to the substance adsorption film having the gel fraction within the specific range, it is possible to improve the heat resistance of the substance adsorption film while suppressing the change in the substance adsorption characteristics due to the formation of the crosslinked structure.

The gel fraction of the substance adsorption film can be adjusted by appropriately adjusting factors such as the type and concentration of the polymer compound, the type and concentration of the cross-linking agent, and the amount of the cross-linking agent relative to the polymer compound. Further, the polymer composition may contain a catalyst within a range that does not affect the substance adsorption properties of the polymer compound, thereby promoting the cross-linking reaction to a desired degree and adjusting the gel fraction.

The substance adsorption film can be formed by a cured polymer composition obtained by drying or curing the above polymer composition by reaction. Therefore, the substance adsorption film can contain at least one component selected from the group consisting of the solid content of the polymer composition and the reaction product of the solid content of the polymer composition. Therefore, as the polymer compound, the same one as explained in the section of the polymer composition can be used. As the polymer compound which may be crosslinked, a polymer compound which may be crosslinked by the crosslinking agent described in the section of the polymer composition can be used. Furthermore, as the crosslinked polymer, a polymer of the crosslinkers described in the section of the polymer composition can be used.

There are no particular restrictions on the size of the substance adsorption film. The substance adsorption film can be formed as a circular film when viewed from the thickness direction. In this case, the diameter of the substance adsorption film is preferably 0.1 μm to 1000 μm, more preferably 0.1 μm to 800 μm, particularly preferably 0.1 μm to 500 μm. When the diameter of the substance adsorption film is small in this way, it is possible to achieve miniaturization of the sensor element.

The thickness of the substance adsorption film can be set appropriately according to the characteristics of the target substance. A specific thickness of the substance adsorption film is preferably 1 nm to 10 μm, more preferably 50 nm to 800 nm. When the substance-adsorbing film has a thickness within the above range, the detection sensitivity of the target substance can generally be increased.

The mass per unit area of the substance adsorption film can be appropriately set according to the properties of the target substance. Specifically, the mass per unit area of the substance adsorption film is preferably 5 μg/cm ² to 50000 μg/cm ² , more preferably 10 μg/cm ² to 10000 μg/cm ² . When the substance adsorption film has a mass per unit area within the above range, the detection sensitivity of the target substance can generally be increased.

[9. Manufacturing method of substance adsorption film]
The substance adsorption film according to this embodiment can be produced using the polymer composition described above. For example, a substance adsorption film is manufactured including a step (I) of forming a polymer composition layer on a support surface and a step (II) of causing a cross-linking reaction with a cross-linking agent contained in the polymer composition layer. can be manufactured by the method.

The support surface on which the polymer composition layer is formed in step (I) is the surface on which the substance adsorption film is formed. Usually, the surface of the transducer portion is used as this support surface. In step (I), the support surface is typically coated with a polymeric composition to form a layer of the polymeric composition.

The method of applying the polymer composition is not particularly limited, but it is preferable to use a dispenser. In the application of a polymer composition using a dispenser, the polymer composition contained in a syringe is usually discharged through a needle, and the discharged polymer composition is adhered to a support surface. . The coating method using a dispenser can suppress the waste of the polymer composition and does not require a mask, so it is excellent in cost and productivity.

The application of the polymer composition is usually carried out in an environment of normal temperature and normal pressure, but the application environment may be adjusted within the range in which the desired substance adsorption film can be obtained. From the viewpoint of forming a substance adsorption film with high reproducibility and stability, the temperature of the coating environment is preferably 0° C. to 30° C., the pressure of the coating environment is preferably 950 hPa to 1080 hPa, and the relative humidity of the coating environment is 10% to 10%. 99% is preferred.

After the layer of the polymer composition is formed in step (I), step (II) is performed in which the cross-linking agent contained in the layer of the polymer composition undergoes a cross-linking reaction. In this step (II), the cross-linking reaction by the cross-linking agent proceeds to form a cross-linked structure, thereby forming a substance adsorption film. Moreover, in this step (II), volatile components such as solvent contained in the polymer composition are usually removed by drying.

In step (II), the layer of the polymer composition is generally heated to cause the cross-linking agent to undergo a cross-linking reaction. The heating temperature is usually set to a temperature at which the cross-linking reaction of the cross-linking agent can proceed. A specific heating temperature is preferably 60° C. or higher, more preferably 80° C. or higher, particularly preferably 100° C. or higher, preferably 250° C. or lower, more preferably 200° C. or lower, and particularly preferably 180° C. or lower. .

The heating time is preferably set so that the cross-linking reaction of the cross-linking agent can proceed sufficiently. A specific heating time is preferably 1 minute to 5 hours, more preferably 10 minutes to 3 hours, still more preferably 20 minutes to 2 hours.

[10. Main Advantages of Substance Adsorption Membrane]
The substance adsorption film described above can have high heat resistance. Specifically, since the flow of the substance adsorption film can be suppressed in a high temperature environment, the planar shape of the substance adsorption film can be maintained in a planar shape in a room temperature environment. Here, the planar shape of the substance adsorption film represents the shape of the substance adsorption film viewed from the thickness direction. Furthermore, the dimensions of the substance adsorption film in a high temperature environment can usually be maintained to the dimensions in a room temperature environment.

The above heat resistance can be evaluated by a fluidity evaluation test. For example, a fluidity evaluation test is performed by attaching a substance adsorption film to a certain surface (for example, an aluminum surface), placing the surface parallel to the vertical direction, and heating the substance adsorption film at 100° C. for 30 minutes. When this fluidity evaluation test is performed, the substance adsorption film after the fluidity evaluation test can usually maintain the same planar shape as before the fluidity evaluation test. Furthermore, the substance adsorption film after the fluidity evaluation test can preferably maintain the same dimensions as before the fluidity evaluation test.

Since the above-described substance adsorption film can suppress changes in substance adsorption characteristics due to the formation of a crosslinked structure, it can have substance adsorption characteristics comparable to those of conventional substance adsorption films that do not have a crosslinked structure. Moreover, the substance adsorption film described above can preferably have the same level of substance adsorption properties as before heating even after heating (for example, at 80° C. for 60 minutes).

The above substance adsorption characteristics can be evaluated by detecting odorants or gas molecules with a sensor element equipped with a substance adsorption film. For example, a sensor element having a substance adsorption film is used to detect odorants or gas molecules. Specifically, changes in physical parameters due to adsorption of substances (odor substances or gas molecules) to the substance adsorption film are detected. Further, this detection is performed for the substance adsorption film according to the present embodiment and the conventional substance adsorption film formed in the same manner as the substance adsorption film according to the present embodiment except that it does not have a crosslinked structure. do in The aforementioned conventional substance adsorption film includes the same polymer compound as that contained in the polymer composition used to form the substance adsorption film according to the present embodiment, but does not contain a crosslinked structure. represents the membrane. When this detection is performed, the amount of change in the parameter detected by the sensor element equipped with the substance adsorption film according to the present embodiment and the amount of change in the parameter detected by the sensor element equipped with the conventional substance adsorption film are usually different. can be close and preferably the same.

The above-mentioned substance adsorption film usually has excellent dimensional retention during the manufacturing process. Specifically, in the manufacturing method for obtaining a substance adsorption film by forming a polymer composition layer on a support surface and causing a cross-linking reaction with a cross-linking agent contained in the polymer composition layer, the polymer composition layer and the size of the substance-adsorbing membrane are preferably close, and particularly preferably the same.

The above-mentioned dimensional retention is determined by the longest length LA seen from the thickness direction of the layer of the polymer composition and the thickness of the substance adsorption film obtained by cross-linking with the cross-linking agent contained in the layer of the polymer composition. It can be evaluated by the dimensional retention rate obtained by the following formula (M3) from the longest length LB as viewed from the direction. The above-described substance adsorption film can have a dimensional retention rate of preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more. The upper limit is usually 100%.
Dimension retention rate = LB/LA x 100 (%) (M3)

[11. sensor element]
FIG. 1 is a side view schematically showing a sensor element 100 according to one embodiment of the invention. As shown in FIG. 1, the sensor element 100 according to one embodiment of the present invention includes the above-described substance adsorption film 120 and the substance adsorption film 120 on the surface 110U. a transducer portion 110 capable of detecting changes in parameters;

As the transducer section 110, an element capable of detecting a physical parameter change caused by the substance adsorption film 120 formed on the surface 110U of the transducer section 110 by adsorption of a substance to the substance adsorption film 120 is usually used. The physical parameters are not particularly limited, for example, surface stress, stress, surface tension, pressure, mass, elasticity, Young's modulus, Poisson's ratio, resonance frequency, frequency, volume, thickness, viscosity, density, magnetic force, magnetic quantity , magnetic field, magnetic flux, magnetic flux density, electrical resistance, electrical quantity, permittivity, power, electric field, charge, current, voltage, potential, mobility, electrostatic energy, capacitance, inductance, reactance, susceptance, admittance, impedance, conductance, Plasmon, refractive index, absorption wavelength, absorbance, luminous intensity, temperature and the like.

The transducer section 110 can be any element capable of detecting changes in the physical parameters described above. Thus, the structure and operation of transducer portion 110 is arbitrary. Preferred transducers 110 include, for example, piezoelectric elements, surface plasmon resonance elements (SPR elements), field effect transistor elements (FET elements), surface acoustic wave elements, charge-coupled elements, metal oxide semiconductor elements, and organic conductive polymer elements. , electrochemical devices, and the like. The piezoelectric element may include a crystal oscillator (QCM).

A piezoelectric element usually includes a piezoelectric body made of a piezoelectric material and electrodes provided on the piezoelectric body. Piezoelectric materials include, for example, quartz crystals, piezoelectric single crystals such as lithium niobate; piezoelectric ceramics such as lead zirconate titanate, barium titanate, and lead titanate; vinylidene fluoride, ethylene trifluoride copolymers, and the like. , a piezoelectric polymer film; and the like. The substance adsorption film 120 may be provided on the surface of the piezoelectric body of the piezoelectric element, or may be provided on the surface of the electrode.

A surface plasmon resonance element usually includes a prism and a metal layer formed on the prism. Examples of materials for the metal layer include gold and silver. The substance adsorption film 120 is usually provided on the surface of the metal layer of the surface plasmon resonance element.

Only one substance adsorption film 120 may be formed for each transducer unit 110, or a plurality of films may be formed.

The sensor element 100 can normally detect, with high sensitivity, changes in substance parameters of the substance adsorption film 120 caused by adsorption of the target substance onto the substance adsorption film 120 . Therefore, the sensor element 100 can have high responsiveness to the target substance. Therefore, by using this sensor element 100, a sensor device having high detection sensitivity can be realized. In addition, since the substance adsorption film 120 according to the present embodiment has improved heat resistance while maintaining substance adsorption characteristics, the sensor element 100 can be used not only in an environment maintained at a low temperature but also in an environment that can reach a high temperature. Also, the target substance can be detected appropriately. Therefore, the sensor element 100 can be provided and used in sensor devices that are assumed to be used in environments that can reach high temperatures, such as for vehicles and factories.

For example, the sensor element 100 includes a step of forming a layer of the polymer composition described above on the surface 110U of the transducer section 110; It can be manufactured by a manufacturing method including: As a method for forming the polymer composition layer on the surface 110U of the transducer section 110, the method described in the section on the method for manufacturing the substance adsorption film can be adopted. Further, the cross-linking reaction of the cross-linking agent contained in the layer of the polymer composition proceeds by heating the layer of the polymer composition as described in the section on the method for producing the substance adsorption film.

When manufacturing a sensor element with a plurality of substance adsorption films, layers of the polymer composition are usually formed a plurality of times. Then, the cross-linking agents contained in the multiple layers of the polymer composition are subjected to a cross-linking reaction to obtain a plurality of substance adsorption films. At this time, the cross-linking reaction may be performed collectively after forming a plurality of layers of the polymer composition. Moreover, the cross-linking reaction may be performed each time one layer of the polymer composition is formed.

[12. sensor device]
The sensor element having the substance-adsorbing film described above can be used as a sensor element for detecting a target substance that can be adsorbed to the substance-adsorbing film. Specifically, it can be used as a sensor element for detecting the target substance by detecting changes in physical parameters caused by the adsorption of the target substance to the physisorption film. Therefore, it is preferable to utilize such advantages and use the sensor element as a sensor element for detecting odorants or gas molecules.

Here, the term "smell" includes a specific single molecule or a collection of molecules consisting of different molecules with different concentrations that can be acquired as olfactory information by humans or living organisms including them.

In addition, the term "odorant" in a broad sense includes substances that can be adsorbed by substance adsorption membranes. Therefore, substances that are not generally regarded as odor-causing substances can also be included in the term "odorant". "Odor" often includes multiple odorants, and may also include unrecognized odorants or unknown odorants. Hereinafter, even when the term "odorant" is simply described, it may mean not an individual odorant but an "aggregate of odorants" that may contain a plurality of odorants.

Furthermore, the term "gas molecule" includes any gaseous molecule. Therefore, the sensor element described above may be used to detect molecules unrelated to odor as target substances.

An example of a sensor device having a sensor element for detecting a gaseous odorant as a target substance will be described below with reference to the drawings. FIG. 2 is a schematic diagram schematically showing a sensor device 200 as an example. As shown in FIG. 2 , the sensor device 200 includes an element mounting section 210 having the sensor element 100 and an output section 220 capable of outputting information on changes in physical parameters detected by the sensor element 100 .

The element mounting section 210 may be provided with a device for extracting information on changes in physical parameters of the substance adsorption film (not shown in FIG. 2) detected by the sensor element 100 .
For example, if the transducer section (not shown in FIG. 2) is a piezoelectric element, the piezoelectric element can usually detect changes in physical parameters of the substance adsorption film as changes in vibration frequency of the piezoelectric element. Therefore, in order to extract this change in frequency, the element mounting section 210 includes wiring for applying an AC voltage to vibrate the piezoelectric element, a frequency meter for measuring the vibration frequency of the piezoelectric element, and the like. may
Further, for example, when the transducer section is a surface plasmon resonance element, the surface plasmon resonance element can usually detect changes in physical parameters of the substance adsorption film as changes in the resonance angle. Therefore, in order to extract this change in resonance angle, the element mounting section 210 includes a light source for irradiating the surface plasmon resonance element with light, a photodetector for detecting reflected light from the surface plasmon resonance element, and the like. may be provided.

The output section 220 is provided so as to output information sent from the sensor element 100 provided in the element mounting section 210 . Examples of the output unit 220 include a display device capable of displaying information on a screen, an interface capable of outputting information to a computer device, and a printer device capable of printing information.

In the method of detecting an odorant using the above device, the sample gas 10 containing the odorant is introduced into the element mounting portion 210 . When an odorant in the introduced sample gas 10 contacts the sensor element 100 , the odorant is adsorbed on the substance adsorption film of the sensor element 100 . This adsorption causes changes in the physical parameters of the substance-adsorbed membrane. Changes in this physical parameter are detected by the transducer portion of the sensor element 100 . For example, if the transducer section is a piezoelectric element, changes in physical parameters of the substance adsorption film can be detected as changes in vibration frequency by the piezoelectric element. Further, for example, if the transducer section is a surface plasmon resonance element, a change in physical parameter of the substance adsorption film can be detected as a change in resonance angle by the surface plasmon resonance element. The information thus detected is typically converted into an electrical signal and sent to the output section 220 .

The output unit 220 outputs the sent information. The output information includes information on changes in physical parameters of the substance-adsorbing film caused by the adsorption of the odorant. Therefore, when the physical parameter changes, it is known that the sample gas 10 contains an odorant, and the odorant can be detected. Further, when the information output from the output device includes information on the amount of change in physical parameters, the amount of odorants in the sample gas 10 may be measured based on the information on the amount of change. In this embodiment, the substance adsorption film provided in the sensor element 100 has improved heat resistance while maintaining the substance adsorption properties. In addition, odorants can be appropriately detected even in environments that can reach high temperatures.

In general, gas contains multiple types of odorants that are the source of odors. The odors perceived by humans may vary depending on the combination pattern of the odorants including the aggregation of these odorants. Therefore, in order to detect these multiple types of odorants, the element mounting portion 210 may be provided with a plurality of sensor elements 100 having substance adsorption films capable of adsorbing the same or different types of target substances. Alternatively, the sensor element 100 provided in the element mounting portion 210 may include a plurality of substance adsorption films capable of adsorbing the same or different types of target substances. With such a configuration, a combination of a plurality of odorants can be detected, so it is possible to appropriately analyze the odor of the sample gas.

The sensor device 200 may further include optional components. For example, the sensor device 200 may include an analysis section (not shown) capable of analyzing information detected by the sensor element 100 . Such an analysis unit may use, for example, a computer device in which an analysis application for analyzing information sent from the sensor element 100 is installed. By utilizing such an analysis unit, it becomes easy to quantitatively and qualitatively analyze the odor of the sample gas.

[13. kit]
The polymeric compositions described above are generally stored and transported in suitable containers. In order to easily supply the polymer composition to the dispenser, it is preferable to employ a syringe attachable to the dispenser as the container. In this case, a kit can be provided that includes a syringe and the polymer composition housed in the syringe. In the kit, the polymer composition is preferably enclosed inside a sealed syringe from the viewpoint of quality maintenance and the like. At this time, the syringe contains the type and amount of the polymer compound, the type and amount of the solvent, the appropriate diameter and thickness of the substance adsorption film formed by the polymer composition, and the target substance that the substance adsorption film can adsorb. A label on which information such as type, etc. is described may be provided.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples. However, the present invention is not limited to the examples shown below. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified.
In addition, unless otherwise specified, the operations described below were performed in the atmosphere at normal temperature and normal pressure (23° C., 1 atm).

[Method for measuring gel fraction]
An aluminum pan was weighed. In this aluminum pan, the polymer compositions produced in Examples and Comparative Examples described later were allowed to stand at 150° C. for 60 minutes to prepare solid evaluation samples. The obtained evaluation sample was weighed together with the aluminum pan, and the weight W (A) of the evaluation sample was obtained by subtracting the previously measured weight of the aluminum pan from the weighed weight.
The solvent used in each example and comparative example was added to the aluminum pan containing the evaluation sample, and left to stand for 24 hours to dissolve or swell the evaluation sample. The dissolved or swollen evaluation sample was subjected to suction filtration, washed with the solvent, and then washed with acetone to obtain an insoluble matter (gel component). The weight W(B) of this insoluble matter was weighed, and the gel fraction was determined by the following formula (M1). In the examples and comparative examples described later, the obtained gel fraction represents the gel fraction of the evaluation sample of the polymer composition and the gel fraction of the substance adsorption film obtained from the polymer composition. .
[Gel fraction] (%) = W (B) / W (A) x 100 (M1)

[Experimental Group I: Fluidity Evaluation Experimental Group]
Examples and comparative examples relating to the evaluation of the fluidity of the substance adsorption film will be described below.

[Example I-1]
(Manufacture of polymer composition)
Polyallylamine-polycaprolactone copolymer (amine value 9 mgKOH/g, acid value 17 mgKOH/g; hydroxyl group equivalent 1450 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent "SBN-70D" manufactured by Ajinomoto Co.; solid content ratio 0.7; NCO rate 10.1%) at a mass ratio of 6: 0.36, and dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent. to obtain a liquid polymer composition having a solid content concentration shown in Table 1. A portion of this polymer composition was taken and the gel fraction was measured by the method described above.

(Manufacturing of substance adsorption film)
An aluminum pan was prepared and placed so that its bottom surface was horizontal. 25 μl of the polymer composition was dropped on the bottom surface of the aluminum pan, and the pan was placed in an oven at 150° C. for 30 minutes while keeping the bottom surface horizontal. After that, the aluminum pan was taken out of the oven and allowed to stand at room temperature for 30 minutes. A substance adsorption film was formed on the bottom surface of the aluminum pan. This substance adsorption film was photographed.

(Evaluation of liquidity)
A fluidity evaluation test was performed by tilting the bottom surface of the aluminum pan by 90° to make it parallel to the vertical direction and placing it in an oven at 150°C for 30 minutes. After that, the aluminum pan was taken out of the oven and allowed to stand at room temperature for 30 minutes. A photograph of the substance adsorption film on the bottom of the aluminum pan was taken.

By comparing the image of the substance adsorption film taken before the fluidity evaluation test and the image of the substance adsorption film taken after the fluidity evaluation test, the substance adsorption by heating at 150 ° C in the fluidity evaluation test It was checked whether the membrane had flowed. As a result, no flow was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Comparative Example I-1]
A polymer composition and a substance adsorption film were produced and evaluated in the same manner as in Example I-1, except that no blocked isocyanate was used. A photograph of the substance adsorption film of Comparative Example I-1 is shown in FIG. 3 together with a photograph of the substance adsorption film of Example I-1. As can be seen from FIG. 3, in Comparative Example I-1, fluidity of the substance adsorption film was confirmed by the fluidity evaluation test, and the planar shape and dimensions of the substance adsorption film could not be maintained.

[Example I-2]
Polyallylamine-polycaprolactone copolymer (amine value 17 mgKOH/g, acid value 14 mgKOH/g; hydroxyl group equivalent 1550 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent "SBN-70D" manufactured by the company; solid content ratio 0.7) at a mass ratio of 6:0.55, dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent, and shown in Table 1. A liquid polymer composition having a solid concentration was obtained. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-1. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Comparative Example I-2]
A polymer composition and a substance adsorption film were produced and evaluated in the same manner as in Example I-2, except that no blocked isocyanate was used. A photograph of the substance adsorption film of Comparative Example I-2 is shown in FIG. 4 together with a photograph of the substance adsorption film of Example I-2. As can be seen from FIG. 4, in Comparative Example I-2, flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could not be maintained.

[Example I-3]
Polyallylamine-polycaprolactone copolymer (amine value 17 mgKOH/g, acid value 20 mgKOH/g; hydroxyl group equivalent 1550 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent "SBN-70D" manufactured by Ajinomoto Co.; solid content ratio 0.7) at a mass ratio of 6:0.54, dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent, and shown in Table 1. A liquid polymer composition having a solid concentration was obtained. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-1. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Comparative Example I-3]
A polymer composition and a substance adsorption film were produced and evaluated in the same manner as in Example I-3, except that no blocked isocyanate was used. A photograph of the substance adsorption film of Comparative Example I-3 is shown in FIG. 5 together with a photograph of the substance adsorption film of Example I-3. As can be seen from FIG. 5, in Comparative Example I-3, flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could not be maintained.

[Example I-4]
Polyallylamine-polycaprolactone copolymer (amine value 17 mg KOH/g, acid value 16 mg KOH/g; hydroxyl equivalent 770 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent "SBN-70D" manufactured by the company; solid content ratio 0.7) at a mass ratio of 6:0.36, dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent, and shown in Table 1. A liquid polymer composition having a solid concentration was obtained. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-1. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Comparative Example I-4]
A polymer composition and a substance adsorption film were produced and evaluated in the same manner as in Example I-4, except that no blocked isocyanate was used. A photograph of the substance adsorption film of Comparative Example I-4 is shown in FIG. 6 together with a photograph of the substance adsorption film of Example I-4. As can be seen from FIG. 6, in Comparative Example I-4, flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could not be maintained.

[Summary of results of Examples I-1 to I-4 and Comparative Examples I-1 to I-4]
The results of Examples I-1 to I-4 and Comparative Examples I-1 to I-4 are summarized in Table 1 below. Since the substance adsorption films did not flow at 150°C as in Examples I-1 to I-4, the substance adsorption films of Examples I-1 to I-4 do not flow at the lower temperature of 100°C. is recognized.
In the table below, the abbreviations have the following meanings.
AA-CL copolymer: Polyallylamine-polycaprolactone copolymer.

[Example I-5]
Polyallylamine-polycaprolactone copolymer (amine value 9 mgKOH/g, acid value 17 mgKOH/g; hydroxyl group equivalent 1450 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent "SBN-70D" manufactured by the company; solid content ratio 0.7) at a mass ratio of 40: 3, dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent, and the solid content shown in Table 2 A liquid polymer composition having a concentration was obtained. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-1. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Example I-6]
Polyallylamine-polycaprolactone copolymer (amine value 9 mgKOH/g, acid value 17 mgKOH/g; hydroxyl group equivalent 1450 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent manufactured by "SBN-70D"; solid content ratio 0.7) at a mass ratio of 40: 1.45, dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent, and shown in Table 2. A liquid polymer composition having a solid concentration was obtained. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-1. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Example I-7]
Polyallylamine-polycaprolactone copolymer (amine value 17 mg KOH/g, acid value 16 mg KOH/g; hydroxyl equivalent 770 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent manufactured by "SBN-70D"; solid content ratio 0.7) at a mass ratio of 40: 6.5, dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent, and shown in Table 2. A liquid polymer composition having a solid concentration was obtained. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-1. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Example I-8]
Polyallylamine-polycaprolactone copolymer (amine value 17 mg KOH/g, acid value 16 mg KOH/g; hydroxyl equivalent 770 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent "SBN-70D" manufactured by the company; solid content ratio 0.7) at a mass ratio of 20: 0.9, dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent, and shown in Table 2. A liquid polymer composition having a solid concentration was obtained. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-1. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Summary of results of Examples I-5 to I-8]
The results of Examples I-5 to I-8 are summarized in Table 2 below. Since the substance adsorption films did not flow at 150°C as in Examples I-5 to I-8, the substance adsorption films of Examples I-5 to I-8 do not flow at the lower temperature of 100°C. is recognized.
In the table below, the abbreviations have the following meanings.
AA-CL copolymer: Polyallylamine-polycaprolactone copolymer.

[Example I-9]
(Manufacture of polymer composition)
Polyurethane (“PU-1020” manufactured by Taisei Fine Chemical Co., Ltd.; hydroxyl equivalent weight 23000 g/eq.) as a polymer compound having a hydroxyl group, and blocked isocyanate (“TPA-B80E” manufactured by Asahi Kasei Corporation; solid content ratio 0) as a cross-linking agent .8; NCO rate 12.5%) were mixed at a mass ratio of 1.06:0.228 and dissolved in tetralin as a solvent to obtain a liquid polymer composition having a solid content concentration shown in Table 3. rice field. A portion of this polymer composition was taken and the gel fraction was measured by the method described above.

(Fluidity evaluation test)
A fluidity evaluation test was performed by tilting the bottom surface of the aluminum pan by 90° to make it parallel to the vertical direction and placing it in an oven at 100°C for 30 minutes. After that, the aluminum pan was taken out of the oven and allowed to stand at room temperature for 30 minutes. A photograph of the substance adsorption film on the bottom of the aluminum pan was taken.

By comparing the image of the substance adsorption film taken before the fluidity evaluation test and the image of the substance adsorption film taken after the fluidity evaluation test, the substance adsorption by heating at 100 ° C. in the fluidity evaluation test It was checked whether the membrane had flowed. As a result, no flow was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Example I-10]
Polyurethane ("PU-1020" manufactured by Taisei Fine Chemical Co., Ltd.) as a polymer compound having a hydroxyl group, and blocked isocyanate ("SBN-70D" manufactured by Asahi Kasei Co., Ltd.; solid content ratio 0.7) as a cross-linking agent, at a mass ratio of 1 .06:0.152 and dissolved in tetralin as a solvent to obtain a liquid polymer composition having a solid concentration shown in Table 3. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-9. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Example I-11]
Polyurethane (“PU-1020” manufactured by Taisei Fine Chemical Co., Ltd.) as a polymer compound having a hydroxyl group, and blocked isocyanate (“SBB-70P” manufactured by Asahi Kasei Co., Ltd.; NCO rate 10.1%) as a cross-linking agent, at a mass ratio of 1 The mixture was mixed at a ratio of 0.06:0.134 and dissolved in tetralin as a solvent to obtain a liquid polymer composition having a solid content concentration shown in Table 3. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-9. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Comparative Example I-5]
A polymer composition and a substance adsorption film were produced and evaluated in the same manner as in Example I-9, except that no blocked isocyanate was used. As a result, flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could not be maintained.

[Summary of results of Examples I-9 to I-11 and Comparative Example I-5]
The results of Examples I-9 to I-11 and Comparative Example I-5 are summarized in Table 3 below.

[Example I-12]
Polyallylamine-polycaprolactone copolymer (amine value 9 mg KOH / g, acid value 17 mg KOH / g; hydroxyl equivalent 1450 g / eq.) as a polymer compound having a hydroxyl group and an amino group, epoxy resin (Nippon Steel Chemical & Materials Co., Ltd. "ZX-1059"; epoxy group equivalent 165 g / eq.; weight average molecular weight 330), styrene maleic anhydride copolymer as a cross-linking agent (EF80, Cray Valley; anhydride group equivalent 105-135 g / eq. .; weight average molecular weight 14400), and imidazole ("2E4MZ" manufactured by Shikoku Kasei Co., Ltd.) as a catalyst were mixed at a mass ratio of 3.0: 0.15: 0.4: 0.11, and 1,3-dimethyl -2-imidazolidinone to obtain a liquid polymer composition having a solid concentration shown in Table 4. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-9. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Example I-13]
Polyallylamine-polycaprolactone copolymer (amine value 9 mg KOH / g, acid value 17 mg KOH / g; hydroxyl equivalent 1450 g / eq.) as a polymer compound having a hydroxyl group and an amino group, acrylic resin as a cross-linking agent (Shin Nakamura Chemical "A-DCP" manufactured by Kogyo Co., Ltd.; molecular weight 304) and a peroxide ("Perhexa HC" manufactured by NOF Corporation) as a polymerization initiator were mixed at a mass ratio of 2.0: 0.48: 0.64. , and dissolved in 1,3-dimethyl-2-imidazolidinone as a solvent to obtain a liquid polymer composition having a solid concentration shown in Table 4. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-9. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Example I-14]
Polyurethane (“PU-1020” manufactured by Taisei Fine Chemical Co., Ltd.) as a polymer compound having a hydroxyl group, epoxy resin (“ZX-1059” manufactured by Nippon Steel Chemical & Materials Co., Ltd.) as a cross-linking agent, styrene maleic anhydride as a cross-linking agent A copolymer (EF80, Cray Valley) and imidazole (manufactured by Shikoku Kasei Co., Ltd. "2E4MZ") as a catalyst were mixed at a mass ratio of 1.3: 0.15: 0.4: 0.11, and By dissolving in tetralin, a liquid polymer composition having a solid concentration shown in Table 4 was obtained. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example I-9. As a result, no flow of the substance adsorption film was confirmed, and the planar shape and dimensions of the substance adsorption film could be maintained.

[Summary of the results of Examples I-12 to I-14]
The results of Examples I-12 to I-14 are summarized in Table 4 below. In the table below, the abbreviations have the following meanings.
AA-CL copolymer: Polyallylamine-polycaprolactone copolymer.

[Experimental Group II: Experimental Group for Evaluation of Substance Adsorption Properties]
Examples and comparative examples relating to evaluation of substance adsorption characteristics of substance adsorption films will be described below.

[Example II-1]
Polyallylamine-polycaprolactone copolymer (amine value 9 mgKOH/g, acid value 17 mgKOH/g; hydroxyl group equivalent 1450 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent ("Duranate SBN-70D" manufactured by Sanken Co., Ltd.) at a solid content mass ratio of 25:1 and dissolved in 1,3-dimethyl-2-imidazolidinone to produce a polymer composition. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 1.31% by mass.

[Comparative Example II-1]
A polymer composition was produced in the same manner as in Example II-1, except that no blocked isocyanate was used. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 0.00% by mass.

[Example II-2]
Polyallylamine-polycaprolactone copolymer (amine value 17 mgKOH/g, acid value 14 mgKOH/g; hydroxyl group equivalent 1550 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent ("Duranate SBN-70D" manufactured by Sanken Co., Ltd.) at a solid content mass ratio of 25:1 and dissolved in 1,3-dimethyl-2-imidazolidinone to produce a polymer composition. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 0.73% by mass.

[Comparative Example II-2]
A polymer composition was produced in the same manner as in Example II-2, except that no blocked isocyanate was used. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 0.00% by mass.

[Example II-3]
Polyallylamine-polycaprolactone copolymer (amine value 17 mgKOH/g, acid value 20 mgKOH/g; hydroxyl group equivalent 1550 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent ("Duranate SBN-70D" manufactured by Sanken Co., Ltd.) at a solid content mass ratio of 25:1 and dissolved in 1,3-dimethyl-2-imidazolidinone to produce a polymer composition. A portion of this polymer composition was taken and the gel fraction was measured by the method described above, and found to be 0.13% by mass.

[Comparative Example II-3]
A polymer composition was produced in the same manner as in Example II-3, except that no blocked isocyanate was used. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 0.00% by mass.

[Example II-4]
Polyallylamine-polycaprolactone copolymer (amine value 17 mg KOH/g, acid value 16 mg KOH/g; hydroxyl equivalent 770 g/eq.) as a polymer compound having a hydroxyl group and an amino group, and blocked isocyanate (Asahi Kasei Co., Ltd.) as a cross-linking agent ("Duranate SBN-70D" manufactured by Sanken Co., Ltd.) at a solid content mass ratio of 25:1 and dissolved in 1,3-dimethyl-2-imidazolidinone to produce a polymer composition. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 2.65% by mass.

[Comparative Example II-4]
A polymer composition was produced in the same manner as in Example II-4, except that no blocked isocyanate was used. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 0.00% by mass.

[Comparative Example II-5]
Polyurethane (“PU-1020” manufactured by Taisei Fine Chemical Co., Ltd.) as a polymer compound was dissolved in 1,2,3,4-tetrahydronaphthalene as a solvent to produce a polymer composition. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 0.00% by mass.

[Comparative Example II-6]
A polymer composition was produced by dissolving modified cellulose (“HP-50” manufactured by Shin-Etsu Chemical Co., Ltd.) as a polymer compound in 1,3-dimethyl-2-imidazolidinone as a solvent. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 0.00% by mass.

[Comparative Example II-7]
A polymer composition was prepared by dissolving polyacrylic acid (manufactured by Sigma-Aldrich Japan, product number: 181285) as a polymer compound in 1,3-dimethyl-2-imidazolidinone as a solvent. A portion of this polymer composition was sampled and the gel fraction was measured by the method described above and found to be 0.00% by mass.

[Evaluation of substance adsorption properties]
(1-1. Formation of substance adsorption film on odor sensor element)
A syringe with a needle (manufactured by Musashi Engineering Co., model number PSY-3E-M, volume 3 ml) and a needle (manufactured by Musashi Engineering Co., model number SNA-32GB, inner diameter 0.1 mm, needle length 13 mm) was prepared. A syringe was filled with the polymer composition, and the needle-equipped syringe was attached to an air pulse dispenser (a high-precision dispenser "Super ΣxIII" manufactured by Musashi Engineering Co., Ltd.). Using this dispenser, the polymer composition was applied by discharging the polymer composition onto the piezoelectric element as the odor sensor chip. Then, it was dried in a drying oven at 150° C. for 30 minutes to obtain an odor sensor element having a substance adsorption film formed thereon.

(1-2. Odor measurement)
The odor sensor element was attached to an odor sensor (manufactured by I-PEX), and the odor was measured according to the following procedure.
A glass petri dish into which an odorant sample (water: ultrapure water, ethanol: manufactured by Junsei Chemical Co., Ltd., 1-propanol: manufactured by Junsei Chemical Co., Ltd., 1-hexanol: manufactured by Junsei Chemical Co., Ltd., toluene: manufactured by Junsei Chemical Co., Ltd.) was attached to the sensor system. In the odor sensor system, the glass petri dish was attached to the exchange position. The glass petri dish was moved to the lower part of the odor sensor, the head space gas in the glass petri dish was released to the odor sensor, and the odor measurement by the odor sensor element was started. Specifically, the amount of response (the amount of change in frequency of the piezoelectric element) caused by the adsorption of the odorant sample to the substance adsorption film was measured. When the amount of response changed over time, the maximum value of the amount of response was obtained as the measured value. After the odor measurement was performed for a certain period of time, the glass petri dish was returned to the replacement position to complete the odor measurement.

We compared the response amount of each odorant sample detected using each substance adsorption film. FIG. 7 shows the amount of response when water was detected as an odorant sample using the odor sensor element. In FIG. 7, comparison between Example II-1 and Comparative Example II-1, comparison between Example II-2 and Comparative Example II-2, comparison between Example II-3 and Comparative Example II-3, and As can be seen by comparing Example II-4 and Comparative Example II-4, the response amounts of Examples II-1 to II-4 with improved heat resistance are lower than those of Comparative Examples without improved heat resistance. It is comparable to the response amount of II-1 to II-4. Therefore, it can be seen that even if the heat resistance is improved by the crosslinked structure, the change in the response amount is small, and therefore the substance adsorption properties can be maintained at the same level.

Next, after the odor measurement was completed, the odor sensor element was taken out from the odor sensor, and the sensor element was heated at 80°C for 60 minutes. After that, the odor sensor element was allowed to cool and returned to normal temperature. The odor sensor element was attached to the odor sensor again, and the odor was measured in the same manner as before heating, and the amount of response of each odorant sample detected using each substance adsorption film was measured.

We compared the response amount of each odorant sample detected using each substance adsorption film after heating. FIG. 8 shows the amount of response when water was detected as an odorant sample using the heated odor sensor element. In FIG. 8, comparison between Example II-1 and Comparative Example II-1, comparison between Example II-2 and Comparative Example II-2, comparison between Example II-3 and Comparative Example II-3, and As can be seen by comparing Example II-4 and Comparative Example II-4, the response amounts of Examples II-1 to II-4 with improved heat resistance are lower than those of Comparative Examples without improved heat resistance. It is comparable to the response amount of II-1 to II-4. Therefore, not only before heating of the substance adsorption film, but also after heating, even if the heat resistance is improved by the crosslinked structure, the change in the response amount is small, and it can be seen that the substance adsorption properties can be maintained at the same level.

Furthermore, two or three substance adsorption films were prepared using the polymer compositions produced in each example and comparative example, and the above odor measurement was performed six times. Then, principal component analysis (PCA) was performed using the measured response amount as a variable. Specifically, a scatter diagram of the response amount of each of the examples and the comparative examples was created. In each example and comparative example, 2 or 3 substance adsorption membranes were used, and 6 measurements were performed on 5 types of odorant samples. Therefore, two or three plots having coordinate values of 6×5=30 dimensions were obtained in each of the example and the comparative example. A straight line Z1 passing through the center of the coordinates of each substance adsorption film and the center of the scatter diagram was drawn, and a straight line Z2 perpendicular to the straight line Z1 and passing through the center of gravity of the coordinates of each substance adsorption film was drawn. A two-dimensional graph with the straight line Z1 as the first component and the straight line Z2 as the second component was obtained as the principal component analysis result.

The first component (component 1: contribution rate 59.7%) and the second component (component 2: contribution rate 15%) obtained by principal component analysis are shown in the graph in FIG. Table 5 shows specific values of the first component and the second component obtained in each example and comparative example. From the results of this principal component analysis, it was confirmed that the coordinates of the corresponding examples and the coordinates of the comparative examples are located close to each other, and that the response patterns of the substance adsorption films are similar. Therefore, this result also confirms that even if the heat resistance is improved by the crosslinked structure, the change in the response amount is small, and therefore the substance adsorption property can be maintained at the same level.

[Experimental Group III: Evaluation Experimental Group for Dimensional Retention Rate]
Examples and comparative examples relating to the evaluation of the dimensional retention rate of the substance adsorption film will be described below.

[Example III-1]
(Manufacture of polymer composition)
Urethane resin (“PU-1020” manufactured by Taisei Fine Chemical Co., Ltd.) as a polymer compound having a hydroxyl group, polyvinyl acetate (“JMR-8LO” manufactured by Nippon Acetate Vipoval Co., Ltd.; saponification degree 9.9 mol) as a polymer compound having a hydroxyl group %; weight average molecular weight 17000 to 25500), and blocked isocyanate (“Duranate SBN-70D” manufactured by Asahi Kasei Co., Ltd.) as a cross-linking agent are mixed at a solid content mass ratio of 47.5: 47.5: 5, and benzoin is used as a solvent. It was dissolved in methyl acid to obtain a liquid polymer composition. A portion of this polymer composition was taken and the gel fraction was measured by the method described above.

(Manufacturing of substance adsorption film)
The polymer composition was applied to the odor sensor chip using a dispenser (Musashi Engineering) to form a layer of the polymer composition. The longest length LA of the layer of this polymeric composition was measured.

(Evaluation of dimensional retention rate)
Thereafter, the odor sensor chip was heated in an oven at 150° C. for 30 minutes to dry methyl benzoate as a solvent from the layer of the polymer composition, thereby obtaining a substance adsorption film. The longest length LB of the substance adsorption film after drying was measured.
The measured lengths LA and LB were substituted into the following formula (M3) to calculate the dimensional retention.
Dimension retention rate = LB/LA x 100 (%) (M3)

[Example III-2]
Urethane resin ("PU-1020" manufactured by Taisei Fine Chemical Co., Ltd.) as a polymer compound having a hydroxyl group, polyvinyl acetate ("JMR-8LO" manufactured by Nippon Acetate Vipoval Co., Ltd.) as a polymer compound having a hydroxyl group, and a cross-linking agent Block isocyanate (“Duranate SBN-70D” manufactured by Asahi Kasei Co., Ltd.) and 2-ethyl-4-imidazole as a catalyst were mixed at a solid content mass ratio of 47:47:5:1, and dissolved in methyl benzoate as a solvent. to obtain a liquid polymer composition. Using the polymer composition thus obtained, a substance adsorption film was produced and evaluated in the same manner as in Example III-1.

[Comparative Example III-1]
Production of a polymer composition and production and evaluation of a substance adsorption film were carried out in the same manner as in Example III-1, except that no blocked isocyanate was used.

[Results of Examples III-1 to III-2 and Comparative Example III-1]
FIG. 10 shows an image of the polymer composition layer taken before drying and an image of the substance adsorption film obtained by drying the polymer composition layer in Example III-1. FIG. 11 shows an image of the polymer composition layer taken before drying and an image of the substance adsorption film obtained by drying the polymer composition layer in Example III-2. FIG. 12 shows an image of the polymer composition layer taken before drying and an image of the substance adsorption film obtained by drying the polymer composition layer in Comparative Example III-1. The results of Examples III-1 to III-2 and Comparative Example III-1 are shown in Table 6 below.

As can be seen from Table 6, shrinkage can be suppressed in the manufacturing process of the substance adsorption films using the polymer compositions according to Examples III-1 and III-2. It was confirmed that the size of the adsorption film can be made the same.

REFERENCE SIGNS LIST 10 sample gas 100 sensor element 110 transducer section 110U surface 120 substance adsorption film 200 sensor device 210 element mounting section 220 output section

Claims

A sensor element comprising: a substance adsorption film; and a transducer unit having the substance adsorption film on its surface and capable of detecting a change in a physical parameter caused by adsorption of a substance to the substance adsorption film. a molecular composition;
the polymer composition comprises a polymer compound, a cross-linking agent, and a solvent;
The cross-linking agent can react with the polymer compound or react with each other to form a cross-linked structure;
A polymer composition, wherein a proportion of a portion that becomes insoluble when an evaluation sample obtained by standing the polymer composition at 150° C. for 60 minutes is immersed in the solvent is 0.10% or more.
The polymer composition according to claim 1, wherein the cross-linking agent has an isocyanate group that may be blocked.
The polymer composition according to claim 1, wherein the polymer compound has a hydroxyl group.
The polymer composition according to claim 1, wherein the polymer compound has an amino group.
A substance adsorption film for a sensor element comprising: a substance adsorption film;
the substance adsorption film contains a polymer compound that may be crosslinked;
The proportion of the portion that becomes insoluble when the substance adsorption film is immersed in at least one solvent selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, tetralin and methyl benzoate is 0.10% or more. is a substance adsorption film.
The substance adsorption film according to claim 5, wherein the substance adsorption film contains the crosslinked polymer compound.
The substance adsorption film according to claim 5, further comprising a polymer having a crosslinked structure.
6. The substance according to claim 5, wherein the substance adsorption film maintains a planar shape when the substance adsorption film is adhered to an aluminum surface and left at rest at 100° C. for 30 minutes with the aluminum surface parallel to the vertical direction. adsorption membrane.
forming a layer of the polymer composition according to any one of claims 1 to 4 on the surface of the transducer part capable of detecting changes in physical parameters;
and a step of causing a cross-linking reaction with a cross-linking agent contained in the polymer composition layer.