Gel composition, member, electronic element, electronic device, and method for producing gel composition

Abstract

[Solution] Provided is a gel composition which contains a vinyl chloride-based resin and a plasticizer and which exhibits a gel state at 20°C. The plasticizer is at least one selected from the group consisting of isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, citric acid esters, acetylcitric acid esters, adipic acid esters selected from di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleic acid esters and derivatives thereof and salts thereof. Also provided is an electronic element comprising a first electrode, a second electrode, and a polymer layer which is disposed between the first electrode and the second electrode and which contains the gel composition.

Description

Gel composition, component, electronic element, electronic device, and method for producing gel composition

[0001] The present invention relates to a gel composition, a member, an electronic device, an electronic apparatus, and a method for producing the gel composition.

[0002] Patent Documents 1 to 5 disclose that a gel-like substance containing polyvinyl chloride and dibutyl adipate can be used as a derivative of an actuator or sensor. Patent Document 6 discloses an actuator including a PVC gel sheet containing polyvinyl chloride and diethyl adipate, dioctyl adipate, diethyl sebacate, dioctyl sebacate, or diethyl succinate. (Prior Art Documents) (Patent Documents) (Patent Document 1) Japanese Patent No. 5392669 (Patent Document 2) Japanese Patent No. 5914003 (Patent Document 3) Japanese Patent Laid-Open No. 2021-112018 (Patent Document 4) Japanese Patent Laid-Open No. 2021-164395 (Patent Document 5) Japanese Patent Laid-Open No. 2021-161365 (Patent Document 6) Japanese Patent Laid-Open No. 2021-161364 General disclosure

[0003] A first aspect of the present invention provides a gel composition comprising a vinyl chloride resin and a plasticizer. The gel composition is in a gel state at 20°C. The plasticizer may be at least one selected from the group consisting of isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, citric acid esters, acetylcitric acid esters, adipate esters selected from di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleic acid esters, derivatives thereof, and salts thereof.

[0004] In the above, the plasticizer may be at least one selected from the group consisting of di-2-ethylhexyl isophthalate (DOIP), di-2-ethylhexyl terephthalate (DOTP), dibutyl fumarate (DBF), di-2-ethylhexyl fumarate (DOF), methyl acetylricinoleate (MAR), acetyl tributyl citrate (ATBC), diethyl fumarate (DEF), diethyl maleate (DEM), dibutyl maleate (DBM), triethyl citrate (TEC), tributyl citrate (TBC), and derivatives thereof, and salts thereof.

[0005] In the above, the gel composition has a tack strength of 0.5 N / cm, measured as the force required to peel the contacting sample and anode when a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm and a thickness of 0.03 cm using an aluminum electrode as the anode. ２ It may be more than that.

[0006] In the above gel composition, when a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm and a thickness of 0.03 cm using a stainless steel mesh electrode having a wire diameter of 0.18 mm, an opening size of 0.67 mm and an opening ratio of 62% as the anode, the sample may undergo a change of 0.5 μm or more.

[0007] In the above, the plasticizer may be at least one selected from the group consisting of di-2-ethylhexyl isophthalate (DOIP), derivatives thereof, and salts thereof. The gel composition may contain (i) 1,000 parts by mass or less of the plasticizer per 100 parts by mass of the vinyl chloride resin. Additionally / alternatively, the gel composition may contain (ii) 200 parts by mass or more of the plasticizer per 100 parts by mass of the vinyl chloride resin.

[0008] In the above, the plasticizer may be at least one selected from the group consisting of di-2-ethylhexyl terephthalate (DOTP), its derivatives, and salts thereof. The gel composition may contain 200 parts by mass or more of the plasticizer per 100 parts by mass of the vinyl chloride resin.

[0009] In a second aspect of the present invention, there is provided a member formed from any of the compositions described above.

[0010] In a third aspect of the present invention, there is provided an electronic device comprising a first electrode, a second electrode, and a polymer layer, the polymer layer being disposed between the first electrode and the second electrode and comprising the gel composition according to any one of claims 1 to 6.

[0011] A fourth aspect of the present invention provides a method for producing a gel composition, comprising a mixing step and a removing step. In the mixing step, a vinyl chloride resin, a plasticizer, and a solvent may be mixed. In the removing step, the mixture of vinyl chloride resin, plasticizer, and solvent obtained in the mixing step may be dried to remove a portion of the solvent from the mixture. The mixture may contain 100 to 1,000 parts by mass of the plasticizer per 100 parts by mass of the vinyl chloride resin. The plasticizer may be at least one selected from the group consisting of isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, citric acid esters, acetylcitric acid esters, adipate esters selected from di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleic acid esters, derivatives thereof, and salts thereof.

[0012] In a fifth aspect of the present invention, the ratio of the total mass of the vinyl chloride resin and the plasticizer to the mass of the mixture may be 80% by mass or more. The plasticizer may be at least one selected from the group consisting of isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, citric acid esters, acetylcitric acid esters, adipate esters selected from di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleic acid esters, derivatives thereof, and salts thereof.

[0013] In a sixth aspect of the present invention, there is provided a gel composition comprising a vinyl chloride resin and a plasticizer, and exhibiting a gel state at 20° C. The tack strength (N / cm ２) and the change in the sample (μm) is 20 μmN / cm ２ The tack strength is measured as the force required to peel a contacting sample and anode when a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm, and a thickness of 0.03 cm, using an aluminum electrode as the anode. The sample change is measured when a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm, and a thickness of 0.03 cm, using a stainless steel mesh electrode having a wire diameter of 0.18 mm, an opening of 0.67 mm, and an opening ratio of 62%, using a stainless steel mesh electrode as the anode.

[0014] In a seventh aspect of the present invention, there is provided a gel composition comprising a vinyl chloride resin and a plasticizer, and being in a gel state at 20° C. The tack strength (N / cm ２ ) and the change in the sample (μm) divided by the change / tack force of 1.5 μm cm ２ / N or more. The tack strength is measured as the force required to peel a contacting sample and anode when a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm, and a thickness of 0.03 cm, using an aluminum electrode as the anode. The sample change is measured when a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm, and a thickness of 0.03 cm, using a stainless steel mesh electrode having a wire diameter of 0.18 mm, an opening of 0.67 mm, and an opening ratio of 62%, using a stainless steel mesh electrode as the anode.

[0015] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions.

[0016] 1A and 1B schematically show an example of a system configuration of an actuator 100. 1C schematically show an example of a system configuration of a sensor 200. 1D schematically show an example of a method for producing a polymer layer 116.

[0017] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention. Not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. Furthermore, the embodiments will be described with reference to the drawings. In the description of the drawings, the same reference numerals may be used to designate the same or similar parts, and redundant description may be omitted.

[0018] (Outline of Actuator 100) Fig. 1 shows an example of a system configuration of an actuator 100. The actuator 100 converts electrical energy into mechanical energy.

[0019] In this embodiment, the actuator 100 includes, for example, a piezoelectric element 110, a driving device 120, and wiring 130. In this embodiment, the piezoelectric element 110 includes, for example, a cathode 112, an anode 114, and a polymer layer 116. Note that the polymer layer in this embodiment is a member formed from a gel composition. More specifically, the piezoelectric element 110 includes two cathodes 112, one anode 114, and two polymer layers 116. In this embodiment, the cathode 112, the polymer layer 116, the anode 114, the polymer layer 116, and the cathode 112 are arranged in this order.

[0020] In this embodiment, the piezoelectric element 110 converts electrical energy into mechanical energy by utilizing the inverse piezoelectric effect of the polymer layer 116. As described above, in this embodiment, the piezoelectric element 110 includes a pair of a cathode 112 and an anode 114, and a polymer layer 116 disposed between the pair of the cathode 112 and the anode 114. In one embodiment, a portion of the polymer layer 116 is disposed between the pair of the cathode 112 and the anode 114. For example, one end of the polymer layer 116 and its vicinity are disposed between the pair of the cathode 112 and the anode 114. In another embodiment, the entire polymer layer 116 is disposed between the pair of the cathode 112 and the anode 114.

[0021] A pair of cathode 112 and anode 114 applies a voltage to a polymer layer 116 disposed between the pair of cathode 112 and anode 114. The polymer layer 116 deforms in accordance with the magnitude of the applied voltage. The voltage applied may be adjusted as appropriate, but is preferably 10 to 500 V, and more preferably 20 to 400 V.

[0022] The cathode 112 and the anode 114 may be any member capable of applying a voltage to the polymer layer 116, and there are no particular limitations on the material and structure of the cathode 112 and the anode 114. Examples of the structure of the cathode 112 and the anode 114 include the shape, planar dimensions, thickness, etc. Examples of the shape of the cathode 112 and the anode 114 include a plate shape, a foil shape, a comb shape, a mesh shape, etc.

[0023] At least one of the cathode 112 and the anode 114 may have a comb-like or mesh-like shape. In particular, when the anode 114 has a mesh-like shape, the polymer layer 116 can enter the voids in the mesh and cause contraction. The cathode 112 and / or the anode 114 having a comb-like or mesh-like shape can be easily deformed. This reduces the power consumption of the actuator 100.

[0024] In this embodiment, the polymer layer 116 is a polymer layer containing a vinyl chloride resin and a plasticizer. The polymer layer 116 is in a gel state at 20°C. The "gel state" is the state generally referred to as "gel," and is a mixed system of two or more components. For example, a "gel" has properties intermediate between a solid and a liquid, and may be a polymer or a swollen polymer that has absorbed a solvent or the like. Furthermore, for example, a "gel" can be considered to be a state in which polymer chains are connected in a very long network-like manner.

[0025] In one embodiment, the polymer layer 116 includes a piezoelectric material. The polymer layer 116 may be a piezoelectric material. As a result, when pressure is applied to the polymer layer 116, a voltage proportional to the magnitude of the pressure is generated. Furthermore, when a voltage is applied to the polymer layer 116, the polymer layer 116 is deformed. The piezoelectric material may be a type of dielectric material.

[0026] In another embodiment, the polymer layer 116 has tackiness. Tackiness is an index that indicates the degree of stickiness of the surface of a material. The polymer layer 116 may include a tacky piezoelectric material, or may be a tacky piezoelectric material. In yet another embodiment, the polymer layer 116 may have optical path bending properties. Details of the polymer layer 116 will be described later.

[0027] In this embodiment, the driving device 120 controls the operation of the actuator 100. In one embodiment, the driving device 120 controls the timing of applying a voltage to the piezoelectric element 110. In another embodiment, the driving device 120 controls the magnitude of the voltage applied to the piezoelectric element 110. In this embodiment, the wiring 130 electrically connects the piezoelectric element 110 and the driving device 120.

[0028] The actuator 100 may be an example of an electronic device. The piezoelectric element 110 may be an example of an electronic element. The polymer layer 160 may be an example of a gel composition. The cathode 112 may be an example of one of the first electrode and the second electrode. The anode 114 may be an example of the other of the first electrode and the second electrode.

[0029] (Another embodiment) In the present embodiment, the details of the piezoelectric element 110 have been described using as an example a case in which the piezoelectric element 110 includes two cathodes 112, one anode 114, and two polymer layers 116, and the cathodes 112, polymer layers 116, anodes 114, polymer layers 116, and cathodes 112 are arranged in this order. However, the piezoelectric element 110 is not limited to this embodiment. For example, the structure of the piezoelectric element 110, the number of each part constituting the piezoelectric element 110, and / or the shape of each part constituting the piezoelectric element 110 are not limited to this embodiment.

[0030] In another embodiment, the piezoelectric element 110 includes one or more (sometimes referred to as one or more) unit cells including a cathode 112, a polymer layer 116, and an anode 114. In the unit cell, the cathode 112, the polymer layer 116, and the anode 114 are arranged, for example, in this order. In the unit cell, the polymer layer 116 may be in contact with the cathode 112 and the anode 114. The unit cell may have a sheet-like, film-like, or layer-like member different from the polymer layer 116 between the cathode 112 and the anode 114. When the piezoelectric element 110 includes multiple single unit cells, adjacent unit cells may share a single cathode 112, or adjacent unit cells may share a single anode 114. When the piezoelectric element 110 includes multiple single unit cells, the multiple unit cells may be combined so that the cathode 112 is the outermost layer of the piezoelectric element 110, or the multiple unit cells may be combined so that the anode 114 is the outermost layer of the piezoelectric element 110.

[0031] In still another embodiment, a plurality of polymer layers 116 may be disposed between the cathode 112 and the anode 114. The piezoelectric element 110 includes, for example, a plurality of polymer layers 116 that are independent of one another between the cathode 112 and the anode 114. Each of the plurality of polymer layers 116 may have a substantially polygonal prism, polygonal pyramid, cylinder, cone, elliptical cylinder, or elliptical cone shape, or may have a shape similar to these.

[0032] In this embodiment, the actuator 100, which is an example of an electronic device, has been described in detail. However, the electronic device is not limited to the actuator 100 according to this embodiment. In other embodiments, the electronic device may be any device that utilizes the inverse piezoelectric effect or the piezoelectric effect of the polymer layer 116.

[0033] The electronic device may be any type of actuator that utilizes the inverse piezoelectric effect of the polymer layer 116, or may be a device that includes such an actuator. The device that includes an actuator may be a device that uses the actuator as a power source. Examples of devices that use an actuator as a power source include artificial muscles, robot suits, robot hands, variable-focus lenses, vibration generators, and tactile displays. Examples of vibration generators include speakers, vibration speakers, and bone conduction speakers.

[0034] The electronic device may be any type of sensor that utilizes the piezoelectric effect of the polymer layer 116, or may be a device that includes such a sensor. Details of the sensor will be described later.

[0035] In this embodiment, an example of the use of the polymer layer 116 has been described, taking as an example a case where the piezoelectric effect or inverse piezoelectric effect of the polymer layer 116 is utilized. However, the use of the polymer layer 116 is not limited to this embodiment. In other embodiments, the tackiness of the polymer layer 116 is utilized. The polymer layer 116 is used, for example, as an adsorbent material, an adhesive material, or the like. The polymer layer 116 may form part of an air purifier or an electrostatic flocking device. In still other embodiments, the optical path bending characteristics of the polymer layer 116 are utilized. The polymer layer 116 forms part of, for example, an optical scanning device or a display.

[0036] (Outline of Sensor 200) Fig. 2 shows an example of a system configuration of the sensor 200. The sensor 200 converts mechanical energy into electrical energy.

[0037] In this embodiment, the sensor 200 includes, for example, a piezoelectric element 210, a detection device 220, and wiring 230. In this embodiment, the piezoelectric element 210 includes, for example, a cathode 112, an anode 114, and a polymer layer 116. More specifically, the piezoelectric element 110 includes one cathode 112, one anode 114, and one polymer layer 116. In this embodiment, the cathode 112, the polymer layer 116, and the anode 114 are arranged in this order.

[0038] In this embodiment, the piezoelectric element 210 converts mechanical energy into electrical energy by utilizing the piezoelectric effect of the polymer layer 116. As described above, in this embodiment, the piezoelectric element 210 includes a pair of cathode 112 and anode 114, and a polymer layer 116 disposed between the pair of cathode 112 and anode 114. In one embodiment, a portion of the polymer layer 116 is disposed between the pair of cathode 112 and anode 114. For example, one end of the polymer layer 116 and its vicinity are disposed between the pair of cathode 112 and anode 114. In another embodiment, the entire polymer layer 116 is disposed between the pair of cathode 112 and anode 114.

[0039] In this embodiment, when pressure is applied to the polymer layer 116 disposed between the pair of cathode 112 and anode 114, a potential difference (sometimes referred to as a voltage) is generated between the pair of cathode 112 and anode 114. The pair of cathode 112 and anode 114 is connected to a detection device 220 via wiring 230. For example, the cathode 112 is electrically connected to one input terminal of the detection device 220, and the anode 114 is electrically connected to the other input terminal of the detection device 220.

[0040] The cathode 112 and the anode 114 may be made of any conductive material, and there are no particular limitations on the material and structure of the cathode 112 and the anode 114. Examples of the structure of the cathode 112 and the anode 114 include the shape, planar dimensions, thickness, etc. Examples of the shape of the cathode 112 and the anode 114 include a plate shape, a foil shape, a comb shape, a mesh shape, etc.

[0041] At least one of the cathode 112 and the anode 114 may have a comb-like or mesh-like shape. In particular, the anode 114 may have a mesh-like shape. The cathode 112 and / or the anode 114 having a comb-like or mesh-like shape can be easily deformed. This allows the polymer layer 116 to easily enter the gaps in the mesh, improving the sensitivity of the sensor 200.

[0042] In this embodiment, the detection device 220 detects the voltage generated between the pair of cathode 112 and anode 114. The detection device 220 may measure the magnitude of the voltage by any known method. In this embodiment, the wiring 230 electrically connects the piezoelectric element 210 and the detection device 220.

[0043] The sensor 200 may be an example of an electronic device, and the piezoelectric element 210 may be an example of an electronic element.

[0044] (Another embodiment) In the present embodiment, the details of the piezoelectric element 210 have been described using as an example a case in which the piezoelectric element 210 includes one cathode 112, one anode 114, and one polymer layer 116, with the cathode 112, the polymer layer 116, and the anode 114 being arranged in this order. However, the piezoelectric element 210 is not limited to this embodiment. For example, the structure of the piezoelectric element 210, the number of parts constituting the piezoelectric element 210, and / or the shape of each part constituting the piezoelectric element 210 are not limited to this embodiment. The piezoelectric element 210 may have a configuration similar to that of the other embodiments described in relation to the piezoelectric element 110.

[0045] (Details of Polymer Layer 116) In this embodiment, the polymer layer 116 includes a gel-like composition (sometimes referred to as a gel composition). The polymer layer 116 may be a gel-like composition. The gel-like composition includes, for example, a vinyl chloride resin and a plasticizer. The gel-like composition exhibits a gel state at, for example, 20°C. The gel-like composition preferably exhibits a gel state at a temperature of -10°C or higher and 50°C or lower, and more preferably exhibits a gel state at a temperature of 5°C or higher and 35°C or lower.

[0046] (A. Composition of Gel Composition) (Vinyl Chloride Resin) In the present embodiment, the vinyl chloride resin may be (i) a homopolymer of vinyl chloride monomer, (ii) a copolymer of vinyl chloride monomer and one or more other polymerizable monomers, or (iii) a chlorinated product of the polymer or copolymer of (i) or (ii). The other polymerizable monomer may be any compound copolymerizable with vinyl chloride monomer, and the details thereof are not particularly limited. When the vinyl chloride resin is a copolymer, the type of the other polymerizable monomer may be selected so that it can be easily molded into a sheet, film, or layer in a state where a plasticizer is added.

[0047] The other polymerizable monomer may be a compound containing an ethylenically unsaturated group. The compound containing an ethylenically unsaturated group may be a compound having one ethylenically unsaturated group in one molecule, or may be a compound having multiple ethylenically unsaturated groups in one molecule.

[0048] Examples of compounds containing an ethylenically unsaturated group include ethylene, propylene, vinylidene chloride, vinyl acetate, vinyl carboxylate monomers, aromatic vinyl monomers, conjugated diene monomers, ethylenically unsaturated monocarboxylic acid esters, ethylenically unsaturated polycarboxylic acid esters, ethylenically unsaturated monocarboxylic acids, ethylenically unsaturated dicarboxylic acids, ethylenically unsaturated ethers, epoxy group-containing monomers, alcoholic hydroxyl group-containing monomers, alkoxyl group-containing monomers, nitrile group-containing monomers, amide group-containing monomers, and amino group-containing monomers.

[0049] The vinyl chloride resin may be substantially free of impurities (sometimes referred to as inevitable impurities) that are mixed in during the raw materials of the vinyl chloride resin and / or the manufacturing process of the vinyl chloride resin.

[0050] The K value of the vinyl chloride resin is not particularly limited, but may be, for example, in the range of 40 to 110, and preferably 45 to 105. The K value is measured in accordance with JIS K 7367-2. Examples of commercially available vinyl chloride resins having such a K value include TK-2500HS and TK-2000E (manufactured by Shin-Etsu Chemical Co., Ltd.), VICIR S2000 (manufactured by Cires), and VICIR S5000 (manufactured by Cires).

[0051] (Plasticizer) (Type of Plasticizer) In the present embodiment, the plasticizer may be at least one selected from the group consisting of isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, citrate esters, acetyl citrate esters, adipate esters selected from di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleic acid esters, derivatives thereof, and salts thereof. This allows a gel composition containing the above plasticizer and the above vinyl chloride resin to become a piezoelectric body.

[0052] As mentioned above, Patent Documents 1 to 5 disclose the preparation of PVC gels containing polyvinyl chloride and dibutyl adipate (sometimes referred to as dibutyl adipate). Patent Documents 1 to 5 describe that various compounds can be used as plasticizers, but only disclose PVC gels containing dibutyl adipate as a plasticizer in the examples. Furthermore, Patent Documents 1 to 5 do not describe or suggest the relationship between the amount of plasticizer added and the degree of the inverse piezoelectric effect of the PVC gel. Furthermore, Patent Documents 1 to 5 do not describe or suggest the relationship between the type and / or amount of plasticizer added and the tackiness of the PVC gel.

[0053] Patent Document 6 discloses the preparation of a PVC gel sheet containing polyvinyl chloride and diethyl adipate, dioctyl adipate, diethyl sebacate, dioctyl sebacate, or diethyl succinate. Patent Document 6 also describes the preparation of PVC gel sheets by varying the concentration of plasticizer, but does not disclose specific experimental results. Furthermore, Patent Document 6 does not describe or suggest the relationship between the amount of plasticizer added and the degree of the inverse piezoelectric effect of the PVC gel. Patent Document 6 also does not describe or suggest the relationship between the type and / or amount of plasticizer added and the tackiness of the PVC gel.

[0054] The present inventors have found that when the plasticizer is at least one selected from the group consisting of adipates selected from isophthalates, terephthalates, fumarates, acetylricinoleates, citrates, acetylcitrates, di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleates, and derivatives thereof, and salts thereof, a gel composition containing the plasticizer and the vinyl chloride resin described above can serve as a piezoelectric material. The present inventors have also found that the gel composition has excellent tackiness.

[0055] Furthermore, the inventors observed the changes in the degree of inverse piezoelectric effect and the degree of tackiness of each of the above gel compositions by changing the amount of plasticizer added. As a result, the inventors found that, depending on the type of plasticizer, (i) the pattern of change in the degree of inverse piezoelectric effect of the gel composition when the amount of plasticizer added is changed, (ii) the pattern of change in the degree of tackiness of the gel composition when the amount of plasticizer added is changed, (iii) the pattern of change in the degree of inverse piezoelectric effect x tackiness of the gel composition when the amount of plasticizer added is changed, and / or (iv) the pattern of change in the (degree of inverse piezoelectric effect / tackiness) of the gel composition when the amount of plasticizer added is changed. It should be noted that the degree of inverse piezoelectric effect can also indicate the degree of piezoelectric effect.

[0056] Specifically, the inventors have found that there are types of plasticizers whose degree of inverse piezoelectric effect in a gel composition increases as the amount added increases, and types of plasticizers whose degree of inverse piezoelectric effect in a gel composition decreases as the amount added increases. Furthermore, the inventors have found that depending on the type of plasticizer, the degree of the inverse piezoelectric effect in a gel composition may have a maximum or minimum value.

[0057] The present inventors have found that there are types of plasticizers that increase the degree of tackiness of a gel composition as the amount added increases, and types of plasticizers that decrease the degree of tackiness of a gel composition as the amount added increases. Furthermore, the present inventors have found that depending on the type of plasticizer, the degree of tackiness of a gel composition may have a maximum or minimum value.

[0058] The present inventors have found that there are plasticizers of which the degree of inverse piezoelectric effect × degree of tackiness of the gel composition generally increases as the amount added increases, those of which the degree of inverse piezoelectric effect increases initially as the amount added increases but then remains constant, and those of which the degree of inverse piezoelectric effect increases initially as the amount added increases and then begins to decrease, etc. The present inventors have also found that, depending on the type of plasticizer, the degree of inverse piezoelectric effect × degree of tackiness of the gel composition may have a maximum or minimum value.

[0059] The present inventors have found that there are plasticizers of which the degree of inverse piezoelectric effect / tackiness of the gel composition generally increases as the amount added increases, those of which the degree initially increases as the amount added increases but then remains constant, and those of which the degree initially increases as the amount added increases and then begins to decrease, etc. The present inventors have also found that depending on the type of plasticizer, the degree of inverse piezoelectric effect / tackiness of the gel composition may have a maximum or minimum value.

[0060] The plasticizer may include an ester of (i) isophthalic acid, terephthalic acid, fumaric acid, acetylricinoleic acid, acetylcitric acid, citric acid, adipic acid, or maleic acid with (ii) an alcohol having 1 to 20 carbon atoms (linear, branched, or cyclic, which may contain an aromatic group and may have a substituent), or a salt of the ester. Examples of the salt of the ester include carbonates, phosphates, and sulfates.

[0061] The plasticizer is preferably at least one selected from the group consisting of di-2-ethylhexyl isophthalate (DOIP), di-2-ethylhexyl terephthalate (DOTP), dibutyl fumarate (DBF), di-2-ethylhexyl fumarate (DOF), methyl acetylricinoleate (MAR), acetyl tributyl citrate (ATBC), diethyl fumarate (DEF), diethyl maleate (DEM), dibutyl maleate (DBM), triethyl citrate (TEC), tributyl citrate (TBC), derivatives thereof, and salts thereof.

[0062] When the plasticizer is di-2-ethylhexyl isophthalate (DOIP), di-2-ethylhexyl terephthalate (DOTP), diethyl fumarate (DEF), diethyl maleate (DEM), dibutyl maleate (DBM), triethyl citrate (TEC), or tributyl citrate (TBC), a gel composition having a higher degree of tackiness is obtained compared to a gel composition containing di-2-ethylhexyl phthalate (DOP), a structural isomer of these compounds, as a plasticizer. Furthermore, compared to when DOP is used as the plasticizer, the balance between the degree of inverse piezoelectric effect and the degree of tackiness can be more easily adjusted.

[0063] Specifically, in a gel composition containing DOP as a plasticizer, as the amount of plasticizer added increases, the degree of the inverse piezoelectric effect of the gel composition increases, and the degree of tackiness of the gel composition decreases rapidly. Therefore, it is relatively difficult to adjust the balance between the degree of inverse piezoelectric effect and the degree of tackiness using DOP as a plasticizer. In contrast, in a gel composition containing DOIP as a plasticizer, as the amount of plasticizer added increases, the degree of the inverse piezoelectric effect of the gel composition increases, and the degree of tackiness of the gel composition decreases relatively slowly. Furthermore, in a gel composition containing DOTP as a plasticizer, as the amount of plasticizer added increases, the degree of the inverse piezoelectric effect of the gel composition increases, and the degree of tackiness of the gel composition also increases. Furthermore, the degree of tackiness has a maximum value.

[0064] Gel compositions containing DEF, DEM, DBM, TEC, or TBC as a plasticizer also tend to exhibit an increase in the degree of inverse piezoelectric effect of the gel composition as the amount of plasticizer added increases, and the degree of tackiness of the gel composition tends to remain constant or decrease relatively slowly.

[0065] As a result, when DOTP and DOIP are used as plasticizers, a gel composition having a high degree of tackiness can be produced relatively easily. In particular, when DOTP is used as a plasticizer, a gel composition having a relatively high degree of inverse piezoelectric effect and a relatively high degree of tackiness can be produced.

[0066] When the plasticizer is dibutyl fumarate (DBF), di-2-ethylhexyl fumarate (DOF), methyl acetylricinoleate (MAR), acetyl tributyl citrate (ATBC), diethyl fumarate (DEF), diethyl maleate (DEM), dibutyl maleate (DBM), triethyl citrate (TEC), and / or tributyl citrate (TBC), a gel composition having a high degree of tackiness is obtained. When the plasticizer is dibutyl fumarate (DBF), di-2-ethylhexyl fumarate (DOF), methyl acetylricinoleate (MAR), and / or tributyl acetyl citrate (ATBC), a gel composition having a high degree of tackiness is obtained, compared to, for example, when the plasticizer is dibutyl adipate (DBA), which is used in the above-mentioned Patent Documents 1 to 6. As a result, the balance between the degree of inverse piezoelectric effect and the degree of tackiness can be easily adjusted.

[0067] (Plasticizer Content) The gel composition may contain 100 parts by mass or more and 1,000 parts by mass or less, preferably 200 parts by mass or more and 800 parts by mass or less, and more preferably 250 parts by mass or more and 700 parts by mass or less of a plasticizer relative to 100 parts by mass of the vinyl chloride resin. This allows for a composition that is in a gel state at 20°C to be obtained. When the plasticizer content is equal to or greater than the lower limit of the above-mentioned range, a piezoelectric body that is in a gel state at 20°C can be obtained. When the plasticizer content is equal to or less than the upper limit of the above-mentioned range, the composition has appropriate viscosity and / or elasticity, and a sheet-like, film-like, or layer-like gel composition can be obtained.

[0068] When the plasticizer is DOIP, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer per 100 parts by mass of the vinyl chloride resin, thereby obtaining a gel composition having a relatively large inverse piezoelectric effect and a large degree of tackiness.

[0069] When the plasticizer is DOTP, the gel composition may contain 200 parts by mass or more of the plasticizer per 100 parts by mass of the vinyl chloride resin. The gel composition may contain 250 parts by mass or more of the plasticizer per 100 parts by mass of the vinyl chloride resin, or may contain 300 parts by mass or more of the plasticizer per 100 parts by mass of the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0070] When the plasticizer is DOTP, the gel composition may contain 800 parts by mass or less, preferably 700 parts by mass or less, of the plasticizer per 100 parts by mass of the vinyl chloride resin. The gel composition may contain 650 parts by mass or less of the plasticizer per 100 parts by mass of the vinyl chloride resin, 600 parts by mass or less of the plasticizer per 100 parts by mass of the vinyl chloride resin, or less than 600 parts by mass of the plasticizer per 100 parts by mass of the vinyl chloride resin. The gel composition may contain 500 parts by mass or less of the plasticizer per 100 parts by mass of the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0071] When the plasticizer is DBF, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 400 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0072] When the plasticizer is DOF, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 600 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0073] When the plasticizer is MAR, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0074] When the plasticizer is ATBC, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 to 400 parts by mass of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0075] When the plasticizer is DEF, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer per 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer per 100 parts by mass of the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0076] When the plasticizer is DEM, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0077] When the plasticizer is DBM, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0078] When the plasticizer is TEC, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0079] When the plasticizer is a TBC, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 500 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0080] When the plasticizer is DOA, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 600 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0081] When the plasticizer is DINA, the gel composition may contain 200 to 800 parts by mass, preferably 250 to 600 parts by mass, of the plasticizer relative to 100 parts by mass of the vinyl chloride resin. The gel composition may contain 300 parts by mass or more of the plasticizer relative to the vinyl chloride resin. This results in a gel composition with a relatively large inverse piezoelectric effect and a high degree of tackiness.

[0082] (Other Additives) The composition preferably contains 100% by weight of the two-component system of polyvinyl chloride and plasticizer, but any additives including other solvents may be blended in an amount of up to 20% by weight.

[0083] (B. Physical Properties of Gel Composition) (Degree of Inverse Piezoelectric Effect) As described above, the gel composition containing the above-mentioned plasticizer is a piezoelectric body, and an actuator and / or a sensor can be realized by utilizing the inverse piezoelectric effect and / or the piezoelectric effect of the gel composition. The degree of the inverse piezoelectric effect of the gel composition can be evaluated, for example, by the deformation amount (μm) of a sample measured by the following procedure.

[0084] According to this embodiment, a sample measuring 1.5 cm in height, 1.5 cm in width, and 0.03 cm in thickness is first cut out from the gel composition to be measured. Next, an aluminum tape-shaped electrode measuring 7.5 cm in height, 2.5 cm in width, and 0.008 cm in thickness is prepared as the cathode. Similarly, a stainless steel mesh electrode with a wire diameter of 0.18 mm, a mesh size of 0.67 mm, and an aperture ratio of 62% is prepared as the anode.

[0085] Next, the cathode is placed on a horizontally arranged, smooth measurement table. The sample is placed on the cathode, and the anode mesh and aluminum tape are slowly placed on top of the sample. Next, a laser displacement meter (Keyence, model number LK-G30) is used to measure the distance between the laser sensor and the aluminum tape on the anode mesh when no voltage is applied to the anode or cathode.

[0086] Next, a voltage is applied to the anode and cathode using a voltage application device (manufactured by Matsusada Precision Co., Ltd., model number HARb-1P30-LFPs). The magnitude of the applied voltage is, for example, 100 V or 300 V. Furthermore, a laser displacement meter (manufactured by Keyence Corporation, model number LK-G30) is used to measure the distance between the laser sensor and the aluminum tape on the anode mesh while a voltage is being applied to the anode and cathode.

[0087] Next, the difference in thickness of the sample before and after the voltage is applied to the anode and cathode is calculated, thereby deriving the deformation amount (μm) of the sample before and after the voltage (for example, 100 V or 300 V as described above) is applied to the anode and cathode.

[0088] When a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm, and a thickness of 0.03 cm using a stainless steel mesh electrode with a wire diameter of 0.18 mm, a mesh size of 0.67 mm, and an aperture ratio of 62% as the anode, the amount of change in the sample is, for example, 0.5 μm or more. The amount of change may be 10 μm or more, and is preferably 20 μm or more. This may enable, for example, an actuator with low power consumption and / or a sensor with good sensitivity to be realized.

[0089] (Degree of Tackiness) As described above, the gel composition containing the above plasticizer has relatively high tackiness. The degree of tackiness of the gel composition can be evaluated, for example, by the tack force measured by the following procedure.

[0090] According to this embodiment, a sample having a height of 1.5 cm, a width of 1.5 cm, and a thickness of 0.03 cm is first cut out from the gel composition to be measured. Next, an aluminum tape-shaped electrode having a height of 2 cm, a width of 3.5 cm, and a thickness of 0.009 cm is prepared as a cathode. Similarly, an aluminum electrode is prepared as an anode.

[0091] Next, an anode is attached to the detection section of a load cell (Kyowa Electric Industry Co., Ltd., Model LTS-500GA). A cathode is placed on a horizontally arranged, smooth measurement table, and a sample is placed on the cathode. After that, the distance between the anode attached to the detection section and the sample is adjusted, and the anode is slowly placed on the sample. The load cell is attached to a Z-axis lift stage (Chuo Seiki Co., Ltd., Model ALV104-HP), and the distance to the sample is adjusted by raising and lowering the load cell.

[0092] Next, a voltage is applied to the anode and cathode using a voltage application device (manufactured by Matsusada Precision Co., Ltd., model number HARb-1P30-LFPs). The magnitude of the applied voltage is, for example, 100 V or 300 V.

[0093] Next, the load cell is slowly raised until the sample peels off from the anode, and the force pulling the load cell at that point is measured. Similarly, the force pulling the load cell at the point when the sample peels off from the anode at an applied voltage of 0 V is measured as the adhesive force. The difference between the pulling force at each applied voltage and the pulling force at 0 V is calculated as the tack force.

[0094] When a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm, and a thickness of 0.03 cm, using an aluminum electrode as the anode, the tack strength measured as the force required to peel the contacting sample from the anode is, for example, 0.5 N / cm ２ The tack strength is 1 N / cm ２ It may be 2 N / cm or more. ２ This makes it possible to realize, for example, an actuator with low power consumption and / or a sensor with good sensitivity.

[0095] The change in the above sample (μm) and tack strength (N / cm ２ ) is 20 μmN / cm when measured at 300 V. ２ or more, preferably 36 μmN / cm ２ More preferably, it is 50 μmN / cm ２ When measured at 100 V, it may be 0.3 μmN / cm ２ or more, preferably 1.3 μmN / cm ２ More preferably, it is 2.0 μmN / cm ２ This allows, for example, the degree of the inverse piezoelectric effect of the gel composition and the tackiness to be increased in a well-balanced manner without bias toward one side. This in turn allows for the realization of an actuator with low power consumption and / or a sensor with good sensitivity. The relationship between the change (μm) and the tackiness (N / cm ２ ) is an example of a more preferred embodiment and is not an essential requirement.

[0096] The change in the sample (μm) was calculated as the tack strength (N / cm ２The change / tack force, when measured at 300 V, is 0.4 μm cm ２ / N or more, preferably 1.5 μm cm ２ / N or more, more preferably 3.0 μm cm ２ / N or more. When measured at 100 V, it may be 0.5 μm cm ２ / N or more, preferably 1.5 μm cm ２ / N or more, more preferably 3.0 μm cm ２ / N or more. This makes it possible to increase the amount of change per tack force, and to enhance the inverse piezoelectric effect when the tack force is adjusted to a constant value. This in turn makes it possible to realize an actuator with low power consumption and / or a sensor with good sensitivity. Note that the ratio of change (μm) / tack force (N / cm ２ The ratio requirement of ) is an example of a more preferred embodiment and is not an essential requirement.

[0097] (C. Method for Producing Gel Composition) A method for producing the polymer layer 116 (more specifically, the gel composition) will be described in detail with reference to Fig. 3. Fig. 3 schematically shows an example of a method for producing the polymer layer 116.

[0098] 3, first, in step 322 (sometimes abbreviated as S), a vinyl chloride resin, a plasticizer, and a solvent are mixed together to obtain a mixture of the vinyl chloride resin, the plasticizer, and the solvent (sometimes referred to as a precursor solution).

[0099] Examples of the solvent include cyclic ether compounds, cyclic ketone compounds, etc. Examples of the cyclic ether compounds include tetrahydrofuran (THF) and dioxane, etc. Examples of the cyclic ketone compounds include cyclohexanone, etc.

[0100] The precursor solution contains, for example, 100 parts by mass or more and 1000 parts by mass or less of a plasticizer with respect to 100 parts by mass of a vinyl chloride resin.

[0101] The precursor solution contains, for example, 1,000 to 3,000 parts by weight of solvent per 100 parts by weight of vinyl chloride resin. The precursor solution may contain 1,500 to 2,500 parts by weight of solvent per 100 parts by weight of vinyl chloride resin. In this case, stirring is preferably performed for approximately 1 hour to 2 weeks, preferably 12 hours to 10 days, as necessary, since this allows the vinyl chloride resin and plasticizer to be mixed uniformly. Furthermore, stirring conditions are not particularly limited as long as they result in uniform mixing, but stirring at 50 to 2,000 rpm, preferably 100 to 1,000 rpm, is recommended.

[0102] Next, in S324, the precursor solution is poured onto an appropriate petri dish to a desired thickness. Next, in S326, a drying step of the precursor solution is carried out. This removes a portion of the solvent from the precursor solution. The drying step is carried out, for example, at a temperature of 5°C or higher and 35°C or lower. The drying step can be carried out, for example, at the above temperature for one day or more, preferably one week to three weeks, to form a gel-like polymer-forming member. The thickness of the member can be adjusted appropriately depending on the purpose, but is preferably 0.01 to 0.1 cm.

[0103] In the drying step, gelation proceeds, and a gel composition containing a vinyl chloride resin and a plasticizer is obtained. The ratio of the mass of the solvent to the mass of the gel composition after drying may be 1 mass% or less, or may be less than 0.1 mass%.

[0104] In this embodiment, an example of a method for producing a gel composition has been described, taking as an example a case where step S322 is performed using a vinyl chloride resin prepared in advance. However, the method for producing a gel composition is not limited to this embodiment. In other embodiments, before step S322 is performed, a step of removing at least a portion of impurities contained in the vinyl chloride resin may be further performed. Examples of such impurities include the inevitable impurities described above. In this case, in step S322, the vinyl chloride resin from which the impurities have been removed, a plasticizer, and a solvent are mixed to prepare a precursor solution.

[0105] The ratio of the total mass of the vinyl chloride resin and the plasticizer to the mass of the mixture may be 80% by mass or more, or 90% by mass or more, or 80% by mass or more to 100% by mass or less.

[0106] The present invention will be specifically described below with reference to examples. Note that the present invention is not limited to the following production examples, synthesis examples, or examples. Furthermore, unless otherwise specified, "parts" represents "parts by mass" and "%" represents "% by mass."

[0107] Example 1 First, 30 g of tetrahydrofuran (THF; manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade 204-08745, purity 99.5%) and 4 g of di-2-ethylhexyl isophthalate (DOIP; manufactured by C.G. Ester Corporation, product name DOIP, purity 99% or higher) were charged into a reaction vessel. While stirring the THF and DOIP using a magnetic stirrer at 500 rpm, 2 g of polyvinyl chloride (PVC; manufactured by Shin-Etsu Chemical Co., Ltd., product name TK-2500HS, K value 84.4, purity 99.5% or higher) was added in small amounts. Thereafter, the mixed solution of THF, DOIP, and PVC was stirred at 500 rpm for one week.

[0108] Next, the mixed solution was poured into a 7.6 cm diameter petri dish. The petri dish was left to stand at a temperature of 5° C. to 35° C. for 2 weeks. As a result, a gel composition having a diameter of 7.6 cm and a thickness of 0.3 mm was obtained.

[0109] (Examples 2 to 4) Gel compositions were prepared in the same manner as in Example 1, except that the amount of plasticizer and / or the amount of THF added was different. Tables 1 to 4 (collectively referred to as "Table 1, etc.") show the amounts of PVC, plasticizer, and THF added in each example.

[0110] Example 5 A gel composition was prepared in the same manner as in Example 1, except that di-2-ethylhexyl terephthalate (DOTP; manufactured by ADEKA Corporation, product name Adeka Cizer D-810, purity 99% or higher) was used as the plasticizer. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 5.

[0111] (Examples 6 to 9) Gel compositions were prepared in the same manner as in Example 5, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0112] Example 10 A gel composition was prepared in the same manner as in Example 1, except that dibutyl fumarate (DBF; manufactured by Tokyo Chemical Industry Co., Ltd., product code F0116, purity 98% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 10.

[0113] (Examples 11 to 13) Gel compositions were prepared in the same manner as in Example 10, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0114] (Example 14) A gel composition was prepared in the same manner as in Example 1, except that di-2-ethylhexyl fumarate (DOF; manufactured by Tokyo Chemical Industry Co., Ltd., product code F0117, purity 98% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 14.

[0115] (Examples 15 to 18) Gel compositions were prepared in the same manner as in Example 14, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0116] (Example 19) A gel composition was prepared in the same manner as in Example 1, except that methyl acetylricinoleate (MAR; manufactured by Tokyo Chemical Industry Co., Ltd., product code A0879, purity 80% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 19.

[0117] (Examples 20 to 22) Gel compositions were prepared in the same manner as in Example 19, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0118] Example 23 A gel composition was prepared in the same manner as in Example 1, except that acetyl tributyl citrate (ATBC; Taoka Chemical Co., Ltd., product name ATBC, purity 99% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 23.

[0119] Examples 24 to 26 Gel compositions were prepared in the same manner as in Example 23, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0120] (Example 27) A gel composition was prepared in the same manner as in Example 1, except that diethyl fumarate (DEF; manufactured by Tokyo Chemical Industry Co., Ltd., product code F0068, purity 98% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 27.

[0121] (Examples 28 to 30) Gel compositions were prepared in the same manner as in Example 27, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0122] (Example 31) A gel composition was prepared in the same manner as in Example 1, except that diethyl maleate (DEM; manufactured by Tokyo Chemical Industry Co., Ltd., product code M0010, purity 90% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 31.

[0123] Examples 32 to 34 Gel compositions were prepared in the same manner as in Example 31, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0124] Example 35 A gel composition was prepared in the same manner as in Example 1, except that dibutyl maleate (DBM; manufactured by Tokyo Chemical Industry Co., Ltd., product code M0009, purity 95% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 35.

[0125] (Examples 36 to 38) Gel compositions were prepared in the same manner as in Example 35, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0126] (Example 39) A gel composition was prepared in the same manner as in Example 1, except that triethyl citrate (TEC; manufactured by Tokyo Chemical Industry Co., Ltd., product code C0367, purity 99% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 39.

[0127] (Examples 40 to 42) Gel compositions were prepared in the same manner as in Example 39, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0128] (Example 43) A gel composition was prepared in the same manner as in Example 1, except that tributyl citrate (TBC; manufactured by Tokyo Chemical Industry Co., Ltd., product code C0366, purity 98% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 43.

[0129] (Examples 44 to 46) Gel compositions were prepared in the same manner as in Example 43, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0130] Example 47 A gel composition was prepared in the same manner as in Example 1, except that di-2-ethylhexyl adipate (DOA; manufactured by Tokyo Chemical Industry Co., Ltd., product code A0163, purity 98% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 47.

[0131] (Examples 48 to 51) Gel compositions were prepared in the same manner as in Example 47, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0132] Example 52 A gel composition was prepared in the same manner as in Example 1, except that diisononyl adipate (DINA; manufactured by New Japan Chemical Co., Ltd., product name: Sanso Cizer DINA, purity 99% or higher) was used as the plasticizer and the amounts of PVC, plasticizer, and THF added were different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Example 52.

[0133] (Examples 53 to 56) Gel compositions were prepared in the same manner as in Example 52, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0134] Example 57 A gel composition was prepared in the same manner as in Example 1, except that TK-2500PE (manufactured by Shin-Etsu Chemical Co., Ltd., K value = 88) was used as the PVC, dibutyl fumarate (DBF; manufactured by Tokyo Chemical Industry Co., Ltd., product code F0116, purity 98% or higher) was used as the plasticizer, and the amount of plasticizer and / or THF added was different. Tables 5 and 6 (collectively referred to as "Table 5, etc.") show the amounts of PVC, plasticizer, and THF added in Example 57.

[0135] Examples 58 to 60 Gel compositions were prepared in the same manner as in Example 57, except that the amounts of PVC, plasticizer, and / or THF added were different. Table 5 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0136] Example 61 A gel composition was prepared in the same manner as in Example 1, except that VICIR S5000 (manufactured by Cires, K value 99) was used as the PVC, dibutyl fumarate (DBF; manufactured by Tokyo Chemical Industry Co., Ltd., product code F0116, purity 98% or higher) was used as the plasticizer, and the amount of plasticizer and / or THF added was different. Table 5 etc. shows the amounts of PVC, plasticizer, and THF added in Example 61.

[0137] (Examples 62 to 64) Gel compositions were prepared in the same manner as in Example 61, except that the amounts of PVC, plasticizer, and / or THF added were different. Table 5 etc. shows the amounts of PVC, plasticizer, and THF added in each example.

[0138] Comparative Example 1 A gel composition was prepared in the same manner as in Example 1, except that di-2-ethylhexyl phthalate (DOP; manufactured by C.G. Ester Corporation, product name DOP, purity 99% or higher) was used as the plasticizer. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Comparative Example 1.

[0139] (Comparative Examples 2 to 4) Gel compositions were prepared in the same manner as in Comparative Example 1, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each Comparative Example.

[0140] Comparative Example 5 A gel composition was prepared in the same manner as in Example 1, except that dibutyl adipate (DBA; Fujifilm Wako Pure Chemical Industries, Ltd., special grade 043-19421, purity 99%) was used as the plasticizer. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in Comparative Example 5.

[0141] (Comparative Examples 6 to 8) Gel compositions were prepared in the same manner as in Comparative Example 5, except that the amount of plasticizer and / or the amount of THF added was different. Table 1 etc. shows the amounts of PVC, plasticizer, and THF added in each Comparative Example.

[0142] (Evaluation) The above-described change and tack strength were measured for the gel compositions prepared in each Example and Comparative Example. The change and tack strength were measured when a voltage of 100 V was applied to the gel composition and when a voltage of 300 V was applied to the gel composition. Table 1 etc. shows the change and tack strength of each Example and Comparative Example when a voltage of 100 V was applied to the gel composition, and the change and tack strength of each Example and Comparative Example when a voltage of 300 V was applied to the gel composition.

[0143] Examples 1 to 26 show that when the plasticizer is at least one selected from the group consisting of isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, acetyl citrate esters, and derivatives thereof, and salts thereof, a gel composition containing the plasticizer and a vinyl chloride resin is a piezoelectric material. It is also shown that the gel composition has excellent tackiness.

[0144] Comparing Examples 1 to 9 with Comparative Examples 1 to 4, it can be seen that when the plasticizer is di-2-ethylhexyl isophthalate (DOIP) and / or di-2-ethylhexyl terephthalate (DOTP), a gel composition having a greater degree of tackiness is obtained compared to a gel composition containing di-2-ethylhexyl phthalate (DOP), a structural isomer of these compounds, as a plasticizer. It can also be seen that, with gel compositions containing DOTP as a plasticizer, the degree of the inverse piezoelectric effect of the gel composition increases as the amount of plasticizer added increases, and the degree of tackiness of the gel composition also increases. Furthermore, it can be seen that when DOTP is used as the plasticizer, a gel composition having a relatively large degree of inverse piezoelectric effect and a relatively large degree of tackiness is obtained.

[0145] Comparing Examples 10-56 with Comparative Examples 5-8, it can be seen that gel compositions with a high degree of tackiness can be obtained when the plasticizer is dibutyl fumarate (DBF), di-2-ethylhexyl fumarate (DOF), methyl acetylricinoleate (MAR), acetyl tributyl citrate (ATBC), diethyl fumarate (DEF), diethyl maleate (DEM), dibutyl maleate (DBM), triethyl citrate (TEC), tributyl citrate (TBC), di-2-ethylhexyl adipate (DOA), and / or diisononyl adipate (DINA). Furthermore, it can be seen that the above gel compositions have a relatively high degree of inverse piezoelectric effect and a high degree of tackiness compared to when the plasticizer is dibutyl adipate (DBA).

[0146] Comparing Examples 5 to 56 with Comparative Examples 1 to 8, it can be seen that when the plasticizer is di-2-ethylhexyl terephthalate (DOTP), dibutyl fumarate (DBF), di-2-ethylhexyl fumarate (DOF), methyl acetylricinoleate (MAR), acetyl tributyl citrate (ATBC), diethyl fumarate (DEF), diethyl maleate (DEM), dibutyl maleate (DBM), triethyl citrate (TEC), tributyl citrate (TBC), di-2-ethylhexyl adipate (DOA), and / or diisononyl adipate (DINA), a gel composition having a large value (particularly when 300 V is applied) obtained by multiplying the degree of inverse piezoelectric effect and the degree of tackiness.

[0147]

[0148] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. Furthermore, matters described for a particular embodiment can be applied to other embodiments to the extent that they are not technically inconsistent. Furthermore, each component may have the same features as other components with the same name but different reference numerals. It is apparent from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0149] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[0150] 100 Actuator 110 Piezoelectric element 112 Cathode 114 Anode 116 Polymer layer 120 Driving device 130 Wiring 200 Sensor 210 Piezoelectric element 220 Detection device 230 Wiring

Claims

1. A gel composition comprising a vinyl chloride resin and a plasticizer, and in a gel state at 20°C, wherein the plasticizer is at least one selected from the group consisting of isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, citric acid esters, acetyl citrate esters, adipate esters selected from di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleic acid esters, derivatives thereof, and salts thereof.

2. The gel composition according to claim 1, wherein the plasticizer is at least one selected from the group consisting of di-2-ethylhexyl isophthalate (DOIP), di-2-ethylhexyl terephthalate (DOTP), dibutyl fumarate (DBF), di-2-ethylhexyl fumarate (DOF), methyl acetylricinoleate (MAR), acetyl tributyl citrate (ATBC), diethyl fumarate (DEF), diethyl maleate (DEM), dibutyl maleate (DBM), triethyl citrate (TEC), tributyl citrate (TBC), derivatives thereof, and salts thereof.

3. When a voltage of 300 V is applied to a sample with a height of 1.5 cm, width of 1.5 cm and thickness of 0.03 cm using an aluminum electrode as the anode, the tack force measured as the force required to peel off the contacting sample and the anode is 0.5 N / cm ２ The gel composition according to claim 1, wherein 4. The gel composition according to claim 1, wherein when a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm and a thickness of 0.03 cm using a stainless steel mesh electrode having a wire diameter of 0.18 mm, an aperture of 0.67 mm and an aperture ratio of 62% as the anode, the amount of change of the sample is 0.5 μm or more.

5. The gel composition according to claim 1, wherein the plasticizer is at least one selected from the group consisting of di-2-ethylhexyl isophthalate (DOIP) and its derivatives and salts, and the gel composition (i) contains 1,000 parts by mass or less of the plasticizer per 100 parts by mass of the vinyl chloride resin, or (ii) contains 200 parts by mass or more of the plasticizer per 100 parts by mass of the vinyl chloride resin.

6. The gel composition according to claim 1, wherein the plasticizer is at least one selected from the group consisting of di-2-ethylhexyl terephthalate (DOTP) and its derivatives and salts, and the gel composition contains 200 parts by mass or more of the plasticizer per 100 parts by mass of the vinyl chloride resin.

7. A member formed from the composition of any one of claims 1 to 6.

8. An electronic device comprising: a first electrode and a second electrode; and a polymer layer disposed between the first electrode and the second electrode and containing the gel composition according to any one of claims 1 to 6.

9. An electronic device comprising the electronic element according to claim 8.

10. A method for producing a gel composition, comprising: mixing a vinyl chloride resin, a plasticizer, and a solvent; and drying the mixture of the vinyl chloride resin, the plasticizer, and the solvent obtained in the mixing step to remove a portion of the solvent from the mixture, wherein the mixture contains 100 to 1,000 parts by mass of the plasticizer per 100 parts by mass of the vinyl chloride resin, and the plasticizer is at least one selected from the group consisting of isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, acetyl citrate esters, citric acid esters, adipate esters selected from di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleic acid esters, derivatives thereof, and salts thereof.

11. A method for producing a gel composition according to claim 10, wherein the total mass of the vinyl chloride resin and the plasticizer relative to the mass of the mixture is 80 mass% or more, and the plasticizer is at least one selected from the group consisting of adipates selected from isophthalic acid esters, terephthalic acid esters, fumaric acid esters, acetylricinoleic acid esters, citric acid esters, acetyl citrate esters, di-2-ethylhexyl adipate (DOA) and diisononyl adipate (DINA), maleic acid esters, derivatives thereof, and salts thereof.

12. A gel composition containing a vinyl chloride resin and a plasticizer, which is in a gel state at 20°C, has a tack strength (N / cm) measured as the force required to peel off a sample that is in contact with an aluminum electrode and anode when a voltage of 300 V is applied to the sample, which is 1.5 cm high, 1.5 cm wide and 0.03 cm thick, using an aluminum electrode as the anode. ２ ) and the change in the amount of change (μm) of the sample when a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm and a thickness of 0.03 cm using a stainless steel mesh electrode having a wire diameter of 0.18 mm, an opening of 0.67 mm and an opening rate of 62% as the anode, is 20 μmN / cm ２ The above is a gel composition.

13. A gel composition containing a vinyl chloride resin and a plasticizer, which is in a gel state at 20°C, has a tack strength (N / cm) measured as the force required to peel off a sample that is in contact with an aluminum electrode and anode when a voltage of 300 V is applied to the sample, which is 1.5 cm high, 1.5 cm wide and 0.03 cm thick, using an aluminum electrode as the anode. ２ A stainless steel mesh electrode having a wire diameter of 0.18 mm, an opening of 0.67 mm, and an opening rate of 62% is used as the anode, and a voltage of 300 V is applied to a sample having a height of 1.5 cm, a width of 1.5 cm, and a thickness of 0.03 cm. The change in the sample (μm) when the voltage of 300 V is applied to the sample is calculated as the change / tack force of 1.5 μmcm. ２ / N or more.

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