JP2018206880A - Flexible wiring body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible wiring body which is flexible and stretchable, has a small change in electrical characteristics (electrical resistance) even when stretched by 10% or more, is stable, and has excellent durability. SOLUTION: A polyester block copolymer (a1) composed of a hard segment (a1) composed of a crystalline aromatic polyester unit and a soft segment (a2) composed of an aliphatic polyether unit and / or an aliphatic polyester unit (as a constituent). A) One selected from the group consisting of 90.0 to 99.7% by weight and an aromatic amine-based antioxidant, a hindered phenol-based antioxidant, a sulfur-based antioxidant and a phosphorus-based antioxidant. Flexible wiring formed by forming a conductive circuit on the surface of a base material made of a thermoplastic elastomer resin composition containing 0.3 to 10.0% by weight of two or more kinds of antioxidants (B). body. [Selection diagram] None

Description

  The present invention relates to a flexible wiring body.

  For conductive circuit wiring bodies used in sensors and actuators, etc., using conductive paste containing metal filler or carbon, etc., the substrate is made of hard glass fiber reinforced epoxy resin, polyimide film, glass, ceramics, etc. New materials are used. On the other hand, the development of using a flexible material as a base material for a wiring body has been advanced for the purpose of stretching and bending, and cross-linked rubbers and elastomers have been studied as base materials. However, if the cross-linking agent (sulfur, sulfur compound, organic peroxide) remains, there is a problem that the metal filler is sulfided or oxidized and the electrical resistance increases.

  Therefore, a flexible wiring comprising an elastomer base material and a wiring including an elastomer and a metal filler disposed on the base material, and the base material and the elastomer used for the wiring do not contain sulfur, a sulfur compound, or an organic peroxide. Body (refer to Patent Document 1), a stretchable circuit board having a stretchable base material and conductive fine particles formed thereon and wiring containing an elastomer, the elastomer being not crosslinked by a crosslinking agent (Patent Document 2) Have been proposed).

Japanese Patent No. 5465124 (pages 1 and 2) JP 2014-236103 A (pages 1 and 2)

  However, these proposals can suppress the sulfidation or oxidation of the metal filler as the conductive material, but cannot prevent deterioration of the elastomer material itself as the base material and cannot maintain the flexibility as the wiring body. There was a problem.

  The present invention has been achieved as a result of investigations to solve the above-mentioned problems of the prior art, and is flexible and stretchable. Even when stretched by 10% or more, the change in electrical characteristics (electric resistance) is small. The present invention relates to a flexible wiring body that is stable and excellent in durability.

  That is, in the first aspect of the present invention, the hard segment (a1) composed of a crystalline aromatic polyester unit and the soft segment (a2) composed of an aliphatic polyether unit and / or an aliphatic polyester unit are used as constituent components. From a group consisting of 90.0 to 99.7% by weight of a polyester block copolymer (A), an aromatic amine-based antioxidant, a hindered phenol-based antioxidant, a sulfur-based antioxidant, and a phosphorus-based antioxidant. A conductive circuit is formed on the surface of a base material made of a thermoplastic elastomer resin composition containing 0.3 to 10.0% by weight of one or more selected antioxidants (B). This is a flexible wiring body.

  In the second aspect of the present invention, a hard segment (a1) composed of a crystalline aromatic polyester unit and a soft segment (a2) composed of an aliphatic polyether unit and / or an aliphatic polyester unit are used as constituent components. The polyester block copolymer (A) 85.0 to 99.6% by weight and a group comprising an aromatic amine-based antioxidant, a hindered phenol-based antioxidant, a sulfur-based antioxidant and a phosphorus-based antioxidant One or two or more selected antioxidants (B) 0.3 to 10.0% by weight and a silane coupling agent (C) 0.1 to 5.0% by weight are blended. It is a flexible wiring body formed by forming a conductive circuit on the surface of a base material made of a thermoplastic elastomer resin composition.

  In the third aspect of the present invention, a hard segment (a1) composed of a crystalline aromatic polyester unit and a soft segment (a2) composed of an aliphatic polyether unit and / or an aliphatic polyester unit are used as constituent components. A group comprising 55.0 to 98.6% by weight of the polyester block copolymer (A) and an aromatic amine-based antioxidant, a hindered phenol-based antioxidant, a sulfur-based antioxidant, and a phosphorus-based antioxidant. One or more selected antioxidants (B) 0.3 to 10.0% by weight, silane coupling agent (C) 0.1 to 5.0% by weight, polyvinyl butyral resin ( D) A flexible wiring body formed by forming a conductive circuit on the surface of a base material made of a thermoplastic elastomer resin composition containing 1 to 30% by weight.

The polyester block copolymer (A) comprises a polybutylene terephthalate / hard segment (a1) derived from terephthalic acid and / or dimethyl terephthalate and isophthalic acid and / or dimethyl isophthalate and 1,4-butanediol. Consisting of isophthalate units,
A preferable condition is that the thermoplastic elastomer resin composition of the base material has a melting point of 120 to 210 ° C. The composite molded body of the present invention is characterized in that the flexible wiring body of the present invention is thermally welded to a molded body made of a different material.

  According to the present invention, as described below, a flexible wiring that is flexible, stretchable, stable in electrical property (electric resistance) with little change even when stretched by 10% or more, and excellent in durability. You can get a body.

  Hereinafter, the present invention will be described in detail.

  The flexible wiring body of the present invention means a wiring body that can detect electrical characteristics with little change or variation in electrical resistance even when the wiring body on which the conductive circuit is formed is stretched. Specifically, the conductive circuit The change in the value when the electrical resistance of the wiring body is not expanded is 10 times or less, preferably 5 times or less, more preferably 3 times or less.

  The polyester block copolymer (A) used in the present invention includes a hard segment (a1) mainly composed of crystalline aromatic polyester units and a soft segment (mainly composed of aliphatic polyether units and / or aliphatic polyester units). and a hard block (a1) is a polyester mainly formed from an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. is there.

  Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, anthracene dicarboxylic acid, diphenyl-4,4′-dicarboxylic acid. Acid, diphenoxyethane dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid, sodium 3-sulfoisophthalate and the like. In the present invention, the aromatic dicarboxylic acid is mainly used. A part of the aromatic dicarboxylic acid is an alicyclic ring such as 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, or 4,4′-dicyclohexyldicarboxylic acid. Or aliphatic dicarboxylic acids such as adipic acid, succinic acid, oxalic acid, sebacic acid, dodecanedioic acid, and dimer acid. Furthermore, ester-forming derivatives of dicarboxylic acids such as lower alkyl esters, aryl esters, carbonates, and acid halides can of course be used equally.

  In the present invention, it is preferable to use two or more of the above acid components, and examples thereof include combinations of terephthalic acid and isophthalic acid, terephthalic acid and dodecanedioic acid, terephthalic acid and dimer acid, and the like. By using two or more acid components, the melting point and crystallinity of the thermoplastic elastomer resin composition can be lowered, flexibility can be imparted, and heat with a molded body made of another dissimilar material. The weldability is also improved.

  Next, specific examples of the diol include diols having a molecular weight of 400 or less, such as 1,4-butanediol, ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol and the like. Diols, 1,1-cyclohexanedimethanol, 1,4-dicyclohexanedimethanol, alicyclic diols such as tricyclodecane dimethanol, and xylylene glycol, bis (p-hydroxy) diphenyl, bis (p-hydroxy) ) Diphenylpropane, 2,2′-bis [4- (2-hydroxyethoxy) phenyl] propane, bis [4- (2-hydroxyethoxy) phenyl] sulfone, 1,1-bis [4- (2-hydroxyethoxy) ) Phenyl] Aromatic diols such as hexane, 4,4′-dihydroxy-p-terphenyl, and 4,4′-dihydroxy-p-quarterphenyl are preferred, and such diols may be ester-forming derivatives such as acetylates, alkali metal salts. It can also be used in the form of Two or more of these dicarboxylic acids, derivatives thereof, diol components and derivatives thereof may be used in combination.

  Preferred examples of such a hard segment (a1) include polybutylene terephthalate units derived from terephthalic acid and / or dimethyl terephthalate and 1,4-butanediol, isophthalic acid and / or dimethyl isophthalate and 1,4-butanediol. Of polybutylene isophthalate units derived from styrene, and copolymers of both are preferably used, particularly preferably terephthalic acid and / or dimethyl terephthalate and isophthalic acid and / or dimethyl isophthalate and 1,4-butane. Those consisting of polybutylene terephthalate / isophthalate units derived from diols are used.

  The soft segment (a2) of the polyester block copolymer (A) used in the present invention is an aliphatic polyether and / or an aliphatic polyester. Aliphatic polyethers include poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, copolymers of ethylene oxide and propylene oxide, poly (propylene oxide) Examples thereof include ethylene oxide addition polymers of glycol and copolymer glycols of ethylene oxide and tetrahydrofuran. Examples of the aliphatic polyester include poly (ε-caprolactone), polyenanthlactone, polycaprylolactone, polybutylene adipate, and polyethylene adipate. From the elastic properties of polyester block copolymers obtained from these aliphatic polyethers and / or aliphatic polyesters, poly (tetramethylene oxide) glycol, poly (propylene oxide) glycol ethylene oxide adducts, ethylene oxide and tetrahydrofuran Are preferably used such as copolymer glycol, poly (ε-caprolactone), polybutylene adipate, and polyethylene adipate, among which poly (tetramethylene oxide) glycol, poly (propylene oxide) glycol ethylene oxide adduct, and The use of a copolymer glycol of ethylene oxide and tetrahydrofuran is preferred. The number average molecular weight of these soft segments is preferably 300 to 6000 in the copolymerized state.

  The copolymerization amount of the soft segment (a2) of the polyester block copolymer (A) used in the present invention is usually 15 to 90% by weight, preferably 35 to 90% by weight, and more preferably 50 to 90% by weight. Yes, the copolymerization ratio of (a1) and (a2) can be set in this way. When the copolymerization amount of the soft segment (a2) is less than 15% by weight, the toughness of the thermoplastic elastomer resin composition is low, which is not preferable because the bonding strength when bonded to a molded body from a different material becomes weak. When it exceeds 90% by weight, the mechanical properties represented by the tensile strength of the thermoplastic elastomer resin composition are inferior.

  The polyester block copolymer (A) used in the present invention can be produced by a known method. Specific examples thereof include, for example, a method of transesterifying a lower alcohol diester of a dicarboxylic acid, an excessive amount of a low molecular weight glycol and a low melting point polymer segment component in the presence of a catalyst, and polycondensing the resulting reaction product, and Any method such as a method in which a dicarboxylic acid, an excess amount of glycol and a low melting point polymer segment component are esterified in the presence of a catalyst and the resulting reaction product is polycondensed may be used.

  In the first embodiment of the thermoplastic elastomer resin composition of the present invention, the blending amount of the polyester block copolymer (A) of the present invention is 90.0 wt% to 99.7 wt%, preferably 92.0 to 99.5% by weight, more preferably 95.0% by weight to 99.0% by weight. If it is less than 90.0% by weight, the thermoplastic elastomer resin composition obtained has low mechanical properties and poor moldability, 99 More than 7% by weight is not preferable because the durability of the substrate is lowered.

  The antioxidant (B) used in the present invention is one selected from the group consisting of aromatic amine antioxidants, hindered phenol antioxidants, sulfur antioxidants and phosphorus antioxidants. Or two or more thereof, among which aromatic amine-based antioxidants are preferably used.

  Specific examples of the aromatic amine antioxidant include phenylnaphthylamine, 4,4′-dimethoxydiphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, and 4-isopropoxydiphenylamine. However, among these, the use of diphenylamine compounds is preferred.

  Specific examples of hindered phenol antioxidants include 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, hydroxy Methyl-2,6-di-t-butylphenol, 2,6-di-t-α-dimethylamino-p-cresol, 2,5-di-t-butyl-4-ethylphenol, 4,4′- Bis (2,6-di-t-butylphenol), 2,2'-methylene-bis-4-methyl-6-t-butylphenol, 2,2'-methylene-bis (4-ethyl-6-t-butylphenol) ), 4,4′-methylene-bis (6-t-butyl-o-cresol), 4,4′-methylene-bis (2,6-di-t-butylphenol), 2,2′-methylene-bis (4-Methyl-6- Chlorylphenol), 4,4′-butylidene-bis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (6-tert-butyl-3-methylphenol), bis (3-methyl-) 4-hydroxy-5-t-butylbenzyl) sulfide, 4,4′-thiobis (6-t-butyl-o-cresol), 2,2′-thiobis (4-methyl-6-t-butylphenol), 2 , 6-Bis (2′-hydroxy-3′-t-butyl-5′-methylbenzyl) -4-methylphenol, diethyl ester of 3,5-di-t-butyl-4-hydroxybenzenesulfonic acid, 2 , 2′-dihydroxy-3,3′-di (α-methylcyclohexyl) -5,5′-dimethyl-diphenylmethane, α-octadecyl-3 (3 ′, 5′-di-t-butyl-4 -Hydroxyphenyl) propionate, 6- (hydroxy-3,5-di-t-butylanilino) -2,4-bis-octyl-thio-1,3,5-triazine, hexamethylene glycol-bis [β- (3 , 5-di-tert-butyl-4-hydroxyphenol) propionate], N, N′-hexamethylene-bis (3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid amide), 2,2- Thio [diethyl-bis-3 (3,5-di-t-butyl-4-hydroxyphenyl) propionate], dioctadecyl ester of 3,5-di-t-butyl-4-hydroxybenzenephosphonic acid, tetrakis [methylene -3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris ( , 5-di-t-butyl-4-hydroxybenzyl) benzene, 1,1,3-tris (2-methyl-4-hydroxy-5-di-t-butylphenyl) butane, tris (3,5-di-) -T-butyl-4-hydroxyphenyl) isocyanurate, tris [β- (3,5-di-t-butyl-4hydroxyphenyl) propionyl-oxyethyl] isocyanurate, and the like. Among these, the use of those having a molecular weight of 500 or more such as tetrakis [methylene-3 (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane is preferable.

  The sulfur-based antioxidant is a compound containing sulfur such as thioether, dithioate, mercaptobenzimidazole, thiocarbanilide, and thiodipropion ester. Among these, the use of a thiodipropion ester-based compound is particularly preferable.

  The phosphorus-based antioxidant is a compound containing phosphorus such as phosphoric acid, phosphorous acid, hypophosphorous acid derivative, phenylphosphonic acid, polyphosphonate, dialkylpentaerythritol diphosphite, and dialkylbisphenol A diphosphite. Among these, it is preferable to use a compound having a sulfur atom in the molecule and a compound having two or more phosphorus atoms in the molecule.

  The total amount of these antioxidants (B) is 0.3 to 10.0% by weight, preferably 0.5 to 8.0% by weight, more preferably 1.0 to 5.0% by weight. .

  When the total blending amount of the antioxidant is less than 0.3% by weight, the degree of obtaining the intended improvement effect is small, and the thermoplastic elastomer resin composition part deteriorates particularly at the part in contact with the conductive ink. On the other hand, if it exceeds 10.0% by weight, blooming will occur and the adhesion of the conductive ink will be adversely affected, and the mechanical strength of the thermoplastic elastomer resin composition will be reduced.

  Moreover, as melting | fusing point of the thermoplastic elastomer resin composition of this invention, Preferably it is 120-210 degreeC, More preferably, it is 130-190 degreeC, More preferably, it is 130-180 degreeC. The molding processability and mechanical properties such as injection molding of the composition are inferior, and when it is higher than 210 ° C., the toughness of the thermoplastic elastomer resin composition is low, and the bonding strength when it is welded to a molded body made of a different material is also obtained. Since it may become weak, it is not preferable.

  In the second aspect of the thermoplastic elastomer resin composition of the present invention, a silane coupling agent (C) is blended. The silane coupling agent (C) used in the present invention is not particularly limited, but preferably has an amino group, epoxy group, vinyl group, allyl group, methacryl group, sulfide group, etc. in one molecule. Of these, a silane coupling agent having an epoxy group is preferably used. Specific examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-aminopropyl ethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and 3- (2-aminoethyl) aminopropyl. Methyldimethosylsilane, 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyl Methyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, vinyltriacetoxy Silane, Nyltrimethoxysilane, vinyltriethoxysilane, acrylyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, etc. Preferably, it is an epoxy group-containing compound, and these can be used alone or in combination of two or more.

  The amount of the silane coupling agent (C) of the present invention is 0.1 to 5.0% by weight, preferably 0.3 to 4.0% by weight, more preferably 0.5 to 3.0% by weight. is there. When the amount of the silane coupling agent is less than 0.1% by weight, the adhesion between the conductive ink and the thermoplastic elastomer resin composition is inferior, and when the thermoplastic elastomer resin composition is bonded to other materials, the bonding strength If it is low, and it exceeds 5.0% by weight, blooming occurs and thermal stability is lowered, which is not preferable.

  In the second aspect of the thermoplastic elastomer resin composition of the present invention, that is, when the silane coupling agent (C) is blended, the blending amount of the polyester block copolymer (A) is 85.0 to 99.6. % By weight, preferably 88.0-99.2% by weight, more preferably 92.0-98.5% by weight. If it is less than 85.0% by weight, the resulting thermoplastic elastomer resin composition has low mechanical properties. Molding processability is inferior, and if it exceeds 99.6% by weight, the bonding strength is lowered, which is not preferable.

  In the third aspect of the thermoplastic elastomer resin composition of the present invention, the polyvinyl butyral resin (D) is added for the purpose of blending the silane coupling agent (C) and improving the weldability to a molded body made of a different material. Add. The silane coupling agent (C) used in the present invention is as described above. Moreover, as polyvinyl butyral resin (D) used for this invention, there is no restriction | limiting in particular and a commercial item can be used, for example, S-Flex BL-1, BL-2, BX by Sekisui Chemical Co., Ltd. -L, BM-S, KS-3, etc., Denka Butyral 3000-1, 3000-2, 3000-4, 4000-2, etc. manufactured by Denki Kagaku Kogyo Co., Ltd. are available, but not limited thereto.

  The blending amount of the polyvinyl butyral resin (D) of the present invention is 1 to 30% by weight, particularly preferably 3 to 20% by weight, and if it is less than 1% by weight, the adhesive property of the conductive ink is poor, and the thermoplastic elastomer resin composition. When bonding to other materials, the bonding strength is low, and if it exceeds 30% by weight, the thermoplastic elastomer resin composition obtained is low in mechanical strength and inferior in moldability, which is not preferable.

  In the third aspect of the thermoplastic elastomer resin composition of the present invention, that is, when the polyvinyl butyral resin (D) is blended, the blending amount of the polyester block copolymer (A) is 55.0 to 98.6 wt. %, Preferably 63.0 to 97.2% by weight, more preferably 72.0 to 95.5% by weight, and if it is less than 55.0% by weight, the resulting thermoplastic elastomer resin composition has low mechanical properties and is molded. The workability is inferior, and if it exceeds 98.6% by weight, the bonding strength decreases, which is not preferable.

  Furthermore, various additives can be added to the thermoplastic elastomer resin composition of the present invention as long as the object of the present invention is not impaired. For example, known molding auxiliaries such as crystal nucleating agents and lubricants, UV absorbers and light-resistant agents such as hindered amine compounds, hydrolysis resistance improvers, colorants such as pigments and dyes, antistatic agents, conductive agents, flame retardants, Reinforcing agents, fillers, plasticizers, release agents and the like can be optionally contained.

  Although the manufacturing method of the thermoplastic elastomer resin composition of this invention is not specifically limited, For example, a polyester block copolymer (A), antioxidant (B), and a silane coupling agent (if needed) C), a raw material blended with the polyvinyl butyral resin (D) can be appropriately employed, such as a method of supplying the raw material to a screw type extruder and melt-kneading.

  The conductive ink used in the present invention is not particularly limited, and is used by printing on the substrate surface when forming a general conductive circuit, conductive film, sensor, etc. What is comprised from resin used as a binder can be used. Further, those added with a dispersant, a curing agent, and the like as necessary, and those added with a crosslinking agent, a vulcanization accelerator, an anti-aging agent, a plasticizer, a softening agent, and the like may be used.

  The conductive particles are not particularly limited, but the material is a highly conductive metal, such as silver, copper, nickel, gold, rhodium, palladium, chromium, titanium, platinum, iron, and alloys thereof. Examples of the nonmetal include carbon-based fillers such as carbon black, graphite powder, and carbon nanotube.

  There is no restriction | limiting in particular also as a shape of electroconductive particle, Flakes shape, spherical shape, needle shape, prismatic shape, aggregated powder, etc. are mentioned, You may use independently or may use together.

  The particle diameter of the conductive particles is not particularly limited, and may be selected in consideration of the compatibility between the conductive particles and the resin serving as a binder. For example, in the case of spherical conductive particles, the average particle diameter is 0. The thing of 01 micrometer or more and 5 micrometers or less is preferable.

  There is no restriction | limiting in particular as resin used as a binder, A thermoplastic resin, a thermosetting resin, or a mixture thereof can be used. Examples of the thermoplastic resin include polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and styrene-based block copolymer-based thermoplastic elastomers. Examples of the thermosetting resin include silicone rubber, ethylene-propylene-diene copolymer, acrylic rubber, urethane rubber, butadiene rubber, and epoxy.

  The conductive circuit of the present invention is preferably formed using conductive ink. As the conductive ink, a commercially available conductive paste having stretch properties can be used, and examples thereof include PE873 manufactured by DuPont Electronics Material Co., Ltd.

  As a method for applying the conductive ink, a known method can be employed. For example, a film or sheet made of the thermoplastic elastomer resin composition of the present invention, or a molded article having a three-dimensional structure obtained by injection molding. Examples of the method include a printing method such as screen printing, ink jet printing, flexographic printing, gravure printing, and pad printing, and a method of forming a conductive circuit on the surface by dipping, spraying, bar code, or the like.

  Furthermore, the flexible wiring body made of the thermoplastic elastomer resin composition of the present invention can be thermally welded to a molded body made of a different material as another material, for example, vinyl chloride resin, ABS resin, PC resin. , Thermoplastic resins such as PBT resins, thermosetting resins such as epoxy resins and phenol resins, inorganic materials such as glass, ceramics and metals, natural rubber (NR), styrene-butadiene rubber (SBR), isoprene rubber ( IR), butyl rubber (IIR), halogenated butyl rubber (X-IIR), chloroprene rubber (CR), ethylene-propylene-diene terpolymer rubber (EPDM), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR) ), Chlorosulfonated polyethylene rubber (CSM), acrylic rubber (ACM), hydrin rubber (CHC) , Various rubbers such as chlorinated polyethylene rubber (CPE) and mixtures thereof or the like is selected as the different materials. Of these, joining with rubber is preferably used in the sense of utilizing the characteristics of the flexible wiring body. In the case of thermal welding, different materials can be welded and joined by heating to a temperature higher than the temperature at which the thermoplastic elastomer resin composition is softened.

  When heat-welding, the conductive ink is applied to the molded body made of the thermoplastic elastomer resin of the present invention to form a conductive circuit, and then heat-welded to the molded body made of different materials. A conductive circuit may be formed by applying a conductive ink after integrating a molded body made of a plastic elastomer resin and a molded body made of a different material.

  The heat welding method is not particularly limited as long as it is a method of making the temperature higher than the softening temperature of the thermoplastic elastomer resin composition of the present invention. For example, a method of irradiating a laser beam, a method of heating with a hot plate, The method of using, the method of heating the molded body itself such as metal and melting the thermoplastic elastomer resin composition, the method of discharging the thermoplastic elastomer resin composition from an injection molding machine or extrusion molding machine, and the method of two-color molding, etc. A method of welding, a thermoplastic elastomer resin composition and a molded body made of different materials are welded together using heat during the reaction at the same time as molding during thermal crosslinking and vulcanization reaction of thermosetting resin and various rubbers, etc. A method for obtaining a molded body or the like can be selected.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to these examples, and can be implemented with appropriate modifications within the scope of the gist of the present invention. In the following examples, “parts” and “%” indicate weight units unless otherwise specified.
Further, the melting point, hardness, tensile breaking strength, tensile breaking elongation, printing adhesion, electrical resistance, durability, and adhesion to EPDM of the thermoplastic elastomer resin compositions in the following examples are evaluated by the following methods. went.

[Melting point]
Using a differential scanning calorimeter DSC-7 manufactured by PerkinElmer Co., Ltd., the melting point was the temperature at which the extreme value of the melting endotherm curve obtained by measuring 10 mg of the sample at a heating rate of 10 ° C./min was used.

[hardness]
120x75x2mm thick square plate is molded from pellets dried in hot air at 80 ° C for 3 hours or more under the molding conditions of cylinder temperature 210 ° C and mold temperature 50 ° C using an injection molding machine (NEX-1000 manufactured by Nissei Plastic Industries). The measurement was performed according to JIS K 7215 after three square plates were stacked.

[Tensile breaking strength, tensile breaking elongation]
JISK7112 No. 2 dumbbell test specimens were molded from hot pellets dried at 80 ° C for 3 hours or more using an injection molding machine (NEX-1000 manufactured by Nissei Plastic Industries) under the molding conditions of cylinder temperature 210 ° C and mold temperature 50 ° C. Molded and measured according to JIS K7113.

[printing]
A thermoplastic elastomer resin composition is formed by a T-die extruder, a sheet of 0.3 mm thickness x 220 mm width is formed, an extruded sheet obtained by cutting a sheet of width 200 x length 200 x thickness 0.3 mm, and injection molding 75 mm wide x 125 mm long x 2 mm thick square plate molded products, respectively, and conductive paste (PE873 manufactured by DuPont Electronics Materials Co., Ltd.) as a conductive ink is printed on the surface of each of them by width 2 mm x long A wiring pattern having a thickness of 100 mm was formed. Thereafter, the substrate was left to stand in an oven at 150 ° C. for 20 minutes, and the coating film was dried to obtain a printed sample (flexible wiring body) in which a conductive circuit was formed on the substrate.

[Print adhesion]
An adhesion test using a cellophane tape based on JIS Z 1522 was performed on a print sample using an extruded sheet and a square plate molded article as a base material. In any of the printed samples, a sample in which the conductive circuit was not peeled off was indicated by “◯”, a sample in which the conductive circuit was partially peeled was indicated by “Δ”, and a sample in which the conductive circuit was peeled off was indicated by “X”.

[Electric resistance]
The electrical resistance between two points (100 mm) at the end of the conductive circuit of the printed sample based on the extruded sheet was measured using a digital multimeter manufactured by Iwasaki Tsushinki Co., Ltd. The measurement is conducted using an Instron 5565 type tensile tester and a tensile tester Instron 5565 type. After fixing the printed sample, the tensile test was performed at a strain rate of 50 mm / min. Resistance was also measured. In addition, the electrical resistance in a state of being stretched by 10% or more was measured and used as an index of flexibility.

[durability]
After the printed sample using the extruded sheet as a base material was treated at 130 ° C. for 100 hours, the electrical resistance at an elongation of 0% and 10% was measured.

[Adhesiveness with EPDM]
Print sample (printing) in which a polytetrafluoroethylene film is formed as a release film in order from the bottom between a lower mold and an upper mold of a 150 mm x 150 mm x 2 mm EPDM molding press mold, and a conductive circuit is formed on an extruded sheet The surface is the release film side), 150 mm x 150 mm x 2 mm size EPDM molded body, release film are laminated and installed, press vulcanized at 150 ° C for 30 minutes, allowed to cool at room temperature for 30 minutes, 150 mm A composite molded body was obtained in which a printed sample using an extruded sheet as a base material was heat-welded on the surface side of a × 150 mm × 2 mm size EPDM molded body. Then, the electrical resistance of elongation 0% and 10% was measured.

The blending composition of EPDM (ethylene-propylene-diene terpolymer rubber) used for the evaluation is as follows.
EPDM: 100.0 parts by weight, zinc white: 5.0 parts by weight, stearic acid: 1.0 parts by weight, carbon black: 80.0 parts by weight, processing oil: 0.3 parts by weight, sulfur: 1.5 parts by weight Part, 2-mercaptobenzothiazole: 0.5 part by weight, tetramethylthiuram disulfide: 1.0 part by weight.

[Reference example]
[Production Method of Polyester Block Copolymer (A-1)]
33.0 parts of terephthalic acid, 10.0 parts of isophthalic acid, 40.3 parts of 1,4-butanediol, and 46.5 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400 were added to 0.04 of titanium tetrabutoxide. 04 parts and 0.02 part of mono-n-butyl-monohydroxytin oxide were charged into a reaction vessel equipped with a helical ribbon type stirring blade and heated at 190 to 220 ° C. for 3 hours to drain the reaction water out of the system. The esterification reaction was carried out. After adding 0.15 part of tetra-n-butyl titanate to the reaction mixture and adding 0.05 part of “Irganox” 1098 (hindered phenol antioxidant manufactured by Ciba Geigy), the temperature was raised to 245 ° C. Then, the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was performed for 1 hour and 50 minutes under the conditions. The obtained polymer was discharged into water in the form of strands and pelletized by cutting. The melting point of the obtained polyester block copolymer (A-1) was 162 ° C.

[Production Method of Polyester Block Copolymer (A-2)]
35.0 parts of terephthalic acid, 33.0 parts of 1,4-butanediol and 57.0 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400, 0.04 part of titanium tetrabutoxide and mono-n-butyl -Both 0.02 parts of monohydroxytin oxide were charged into a reaction vessel equipped with a helical ribbon stirring blade, heated at 190 to 225 ° C for 3 hours, and the esterification reaction was carried out while allowing the reaction water to flow out of the system. 0.2 part of tetra-n-butyl titanate was added to the reaction mixture, and 0.05 part of “Irganox” 1098 (hindered phenol antioxidant manufactured by Ciba Geigy Co.) was added, and the temperature was raised to 245 ° C. Then, the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was performed for 1 hour and 50 minutes under the conditions. The obtained polymer was discharged into water in the form of strands and pelletized by cutting. The melting point of the obtained polyester block copolymer (A-2) was 183 ° C.

[Antioxidant (B)]
Naugard 445 (aromatic amine antioxidant) manufactured by Shiraishi Calcium Co., Ltd.

[Silane coupling agent (C)]
Toray Dow Corning Co., Ltd. Z-6043.

[Polyvinyl butyral resin (D)]
S REC BL-1 manufactured by Sekisui Chemical Co., Ltd.

[Examples 1-5, Comparative Examples 1-5]
Table 1 shows the polyester block copolymers (A-1) and (A-2) obtained in Reference Examples, the antioxidant (B), the silane coupling agent (C), and the polyvinyl butyral resin (D). Mixing using a V-blender at a blending ratio (% by weight) shown, melt kneading at 230 ° C. using a twin screw extruder having a diameter of 45 mm and a triple thread type screw to obtain a thermoplastic elastomer resin composition, This was pelletized.

  The obtained pellets were dried at 80 ° C. for 5 hours, and then inline screw type injection molding machine set at 230 ° C., at a mold temperature of 50 ° C. (surface of the mold cavity), a JIS No. 2 dumbbell test piece and a length of 125 mm A square plate molded product having a width of 75 mm and a thickness of 2 mm was obtained by injection molding, and a sheet having a thickness of 0.3 mm and a width of 220 mm was obtained by T-die extrusion. Table 1 shows the results of evaluation using these as described above.

  As is clear from the results in Table 1, the flexible wiring body based on the thermoplastic elastomer resin composition of the example is excellent in hardness, tensile breaking strength, and tensile breaking elongation, and print adhesion of conductive ink. The electrical resistance values of the conductive circuit at 0%, 10%, and 20% elongation were low, and a stable electrical resistance value was exhibited even after treatment at 130 ° C. for 100 hours for durability evaluation. Furthermore, the flexible wiring body based on the extruded sheet product of the thermoplastic elastomer resin composition of the example had good adhesion by thermal welding with EPDM, and the electric resistance value after welding with EPDM was stable.

  However, the thermoplastic elastomer resin compositions of Examples 3 and 4 are slightly inferior in thermal welding with EPDM. When the thermoplastic elastomer resin composition is elongated by more than 10%, the thermal welding surface of the thermoplastic elastomer resin composition sheet and the EPDM molded body. A part of the peeling occurred.

  Moreover, it is the 2nd aspect of this invention. The thermoplastic elastomer resin composition of Example 5 blended with the silane coupling agent (C) was excellent in thermal welding with EPDM.

  Further, the thermoplastic elastomer resin composition of Example 6 in which the silane coupling agent (C) and the polyvinyl butyral resin (D) according to the third aspect of the present invention are blended is excellent in thermal welding with EPDM, The adhesiveness with EPDM was also most excellent. The adhesiveness of the thermoplastic elastomer resin compositions of Examples 1 and 2 by thermal welding with EPDM was also superior to Examples 3 and 4, but was inferior to Examples 5 and 6 when repeated strain was applied.

  On the other hand, the flexible wiring body based on the thermoplastic elastomer resin composition of Comparative Examples 1 to 5 that does not satisfy the conditions of the present invention is tensile compared to the thermoplastic elastomer resin composition of the examples of the present invention. Either or all of the breaking strength and tensile elongation at break are inferior, the printed adhesiveness of the conductive ink, the electric resistance value of the conductive circuit varies, or the conductive circuit is cut off. Has no role. Especially in Comparative Examples 1, 2, and 5, the base material surface of the thermoplastic elastomer resin composition deteriorated at the portion (conductive circuit portion) where the conductive ink was applied in the durability evaluation (treatment at 130 ° C. × 100 hours). It shattered and the printed conductive circuit peeled off. In Comparative Examples 3 and 4, since the toughness of the thermoplastic elastomer resin composition sheet was lowered and the elongation was not stable, the adhesiveness due to thermal welding with EPDM deteriorated.

  The flexible wiring body of the present invention has sufficient strength and durability even in a conductive circuit wiring body based on a flexible material as described above, and is used for wearable applications, sensors, actuators, and the like. It can be used for conductive circuits and heater wiring bodies, and it can also be used as a molded body made of flexible different materials such as rubber other than thermoplastic elastomer resin composition, and as a composite molded body heat-welded with cushions, mattresses, etc. Can be used.

Claims (6)

A polyester block copolymer (A) comprising as constituent components a hard segment (a1) composed of a crystalline aromatic polyester unit and a soft segment (a2) composed of an aliphatic polyether unit and / or an aliphatic polyester unit; 0 to 99.7% by weight, and one or more selected from the group consisting of aromatic amine antioxidants, hindered phenol antioxidants, sulfur antioxidants and phosphorus antioxidants A flexible wiring body formed by forming a conductive circuit on the surface of a base material composed of a thermoplastic elastomer resin composition containing 0.3 to 10.0% by weight of an antioxidant (B). 85. A polyester block copolymer (A) having a hard segment (a1) composed of a crystalline aromatic polyester unit and a soft segment (a2) composed of an aliphatic polyether unit and / or an aliphatic polyester unit as constituents. 0 to 99.6% by weight, one or more selected from the group consisting of an aromatic amine antioxidant, a hindered phenol antioxidant, a sulfur antioxidant and a phosphorus antioxidant A substrate made of a thermoplastic elastomer resin composition comprising 0.3 to 10.0% by weight of an antioxidant (B) and 0.1 to 5.0% by weight of a silane coupling agent (C). A flexible wiring body formed by forming a conductive circuit on the surface. 55. A polyester block copolymer (A) comprising as constituent components a hard segment (a1) composed of crystalline aromatic polyester units and a soft segment (a2) composed of aliphatic polyether units and / or aliphatic polyester units. 0 to 98.6% by weight, one or more selected from the group consisting of aromatic amine antioxidants, hindered phenol antioxidants, sulfur antioxidants and phosphorus antioxidants Antioxidant (B) 0.3-10.0 wt%, silane coupling agent (C) 0.1-5.0 wt%, and polyvinyl butyral resin (D) 1-30 wt% are blended. A flexible wiring body formed by forming a conductive circuit on the surface of a base material made of a thermoplastic elastomer resin composition. The polyester block copolymer (A) is a polybutylene terephthalate / isophthalate wherein the hard segment (a1) is derived from terephthalic acid and / or dimethyl terephthalate and isophthalic acid and / or dimethyl isophthalate and 1,4-butanediol. It consists of a unit, The flexible wiring body of any one of Claims 1-3 characterized by the above-mentioned. The flexible wiring body according to any one of claims 1 to 4, wherein the thermoplastic elastomer resin composition has a melting point of 120 to 210 ° C. A composite molded body, wherein the flexible wiring body according to any one of claims 1 to 5 is thermally welded to a molded body made of a different material.