JP2010066088A - Film electrode for sensor, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film electrode for sensors in which an electrode substrate, in which an electrode pattern is formed in a film for insulating substrates made of a thermo-plastic resin film, is coated with a film for coating an electrode substrate made of a thermo-plastic resin film without using an adhesive agent, and to provide a liquid level detection apparatus using the same. <P>SOLUTION: The electrode substrate in which the electrode pattern is formed in the film (A) for insulating substrates made of the thermo-plastic resin film is coated with the film (B) for coating electrode substrates made of the thermo-plastic resin film without using an adhesive agent in the film electrode for sensors. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrode and a manufacturing method thereof, and more particularly to an electrode that can be used as a sensor and a manufacturing method thereof. More particularly, the present invention relates to a film electrode for a sensor and a manufacturing method thereof.

  Conventionally, there are a capacitance type sensor and a pressure sensing type sensor as a detection device. Any of the detection devices can detect the liquid level with high accuracy, and is provided, for example, in a fuel tank. In this type of detection device, the measurement electrodes are arranged on the assumption that the bottom surface of the tank and the liquid surface are parallel (horizontal) to each other.

  As an electrode plate of this type, a method of manufacturing an electrode by providing a metal electrode via an adhesive on an insulating substrate, or an electrode substrate provided with a metal electrode via an adhesive on an insulating substrate, further via an adhesive A method for manufacturing an electrode formed by coating an electrode covered with an insulating substrate and a conductive paste on the insulating substrate has been proposed.

  As a capacitive sensor electrode, a method for manufacturing an electrode having a sandwich structure in which a polyimide film is used as an insulating substrate and a copper foil is sandwiched has been proposed. Bondability between polyimide and metal plate, and bondability between polyimides However, when an adhesive is used, there is a problem that the adhesive layer deteriorates due to the solvent used in the use environment and the electrode is peeled off (Patent Documents 1 and 2).

  In addition, as a pressure-sensitive sensor electrode, piezoelectric ceramic powder is embedded in an insulating resin, and there are electrodes made of metal foil on the front and back of the film-like insulating resin, and the piezoelectric ceramic powder penetrates the insulating resin and the metal foil. There are proposed an electrode manufacturing method (Patent Document 3) that detects pressure by contact, and an electrode manufacturing method (Patent Document 4) in which a ceramic thin film is sandwiched between resin films.

  In addition, a liquid level detection sensor for fuel tanks has been proposed with polyimide as a protective layer, but polyimide has a problem of poor durability due to low chemical resistance and hydrolysis resistance. (Patent Document 5).

However, in any electrode, the bondability between the insulating substrate and the electrode thin film or between the insulating substrates is weak, and when an adhesive is used, the adhesive layer deteriorates due to the solvent used in the environment of use, and the electrode peels off. There was a problem. In addition, polyimide has a problem that it is expensive.
Japanese Patent Laid-Open No. 10-235925 Japanese Patent Laid-Open No. H5-223624 JP 2004-191207 A JP 2000-337971 A JP 2004-239711 A

  The present invention is for a sensor obtained by coating an electrode substrate formed by forming an electrode pattern on an insulating substrate film made of a thermoplastic resin film with an electrode substrate covering film made of a thermoplastic resin film without using an adhesive. The present invention has been made for the purpose of providing a film electrode and a liquid level detection apparatus using the film electrode.

  As a result of intensive studies to solve the above problems, the present inventors have developed a film electrode for a sensor in which a metal electrode or a piezoelectric thin film and a metal electrode formed on a thermoplastic resin film are coated with a thermoplastic resin film. A method of development was found and the present invention was reached.

  That is, the present invention relates to an electrode substrate formed by forming an electrode pattern on a film (A) made of a thermoplastic resin (hereinafter this film is also referred to as an insulating substrate film (A)), and a film (B ) (Hereinafter referred to as an electric substrate coating film (B)) without using an adhesive.

  Since the film electrode for a sensor of the present invention is produced without using an adhesive, it is possible to provide a film electrode for a sensor that can be used in a solvent for a long period of time at a low cost.

  In the present invention, a film (A) made of a thermoplastic resin and a film (B) made of a thermoplastic resin are bonded together without using an adhesive, and an electrode pattern is formed between these films.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments.

  In the present invention, the insulating substrate film (A) is a film made of a thermoplastic resin which is exclusively formed with an electrode pattern to serve as an electrode substrate, and the electrode substrate coating film (B) is exclusively the insulating substrate film (A). It becomes a film which coat | covers the electrode formed by laminating | stacking the metal electrode or ceramic thin film and metal which were formed on it.

  In the present invention, the film electrode for a sensor refers to a film-like electrode that can be used as a sensor.

  In the present invention, the capacitance sensor is a sensor that measures displacement by a change in capacitance.

  In the present invention, a pressure-sensitive sensor is a sensor that measures displacement by a change in pressure applied to an electrode.

  When the film electrode for a sensor of the present invention is used as an electrode for a capacitance sensor, a thermoplastic resin film can be used as an insulating substrate for the electrode, and the thermoplastic resin is conductive such as carbon black or metal powder. A film in which particles are blended and dispersed can also be used. The blending amount of the conductive particles is preferably 10 parts by weight or more and less than 60 parts by weight with respect to 100 parts by weight of the thermoplastic resin. More preferably, it is 10 weight part or more and less than 50 weight part.

  When the film electrode for a sensor of the present invention is used as a capacitance sensor, an electrode pattern is provided on the insulating substrate film (A) and then covered with the electrode substrate coating film (B).

  When the electrode of the present invention is used as an electrode of a pressure-sensitive sensor, a method of using piezoelectric ceramic particles as an insulating substrate after blending and dispersing piezoelectric ceramic particles in an insulating resin, or a piezoelectric thin film and an electrode composed of piezoelectric ceramic A method such as a method of coating a thermoplastic resin film after laminating the patterns can be used.

  The blending amount of the piezoelectric ceramic particles is preferably 10 parts by weight or more and less than 50 parts by weight with respect to 100 parts by weight of the thermoplastic resin. More preferably, it is 10 parts by weight or more and less than 30 parts by weight.

As the piezoelectric ceramic, ceramics exhibiting piezoelectricity such as lead zirconate titanate and barium titanate can be widely used, but are not limited thereto. For example, the perovskite structure is lead titanate (PbTiO ₃ ), lead zirconate titanate (Pb (Zr, Ti) O ₃ ), lead zirconate (PbZrO ₃ ), lead lanthanum titanate ((Pb, La) TiO ₃ ). And lead lanthanum zirconate titanate ((Pb, La) (Zr, Ti) O ₃ ), lead magnesium niobium zirconate (Pb (Zr, Ti) (Mg, Nb) O ₃ ) and the like.

  As a method of providing the piezoelectric thin film on the insulating substrate film (A), there is a method of applying a piezoelectric ceramic paste on the insulating substrate in addition to a vapor deposition technique such as chemical vapor deposition, vacuum vapor deposition, and sputtering. It is not something.

  In the present invention, examples of the metal material for forming the electrode pattern include, but are not limited to, conductive materials such as Al, Ni, Pt, Au, Ag, and Cu. A well-known method can be employ | adopted for formation of an electrode pattern.

  The electrode pattern may be provided on the insulating substrate film (A) or the insulating substrate film (A) laminated with the piezoelectric thin film by applying a conductive paste, chemical vapor deposition, vacuum vapor deposition, sputtering method, electroless plating method or metal. A method of laminating foils can be used. It is also possible to form an electrode pattern by screen printing or etching.

  When used as a piezoelectric capacitive sensor, the metal electrode pattern is provided on the insulating substrate film (A) formed by blending piezoelectric ceramic particles using the above-described method, and then coated with the electrode substrate coating film (B). Is done.

  When a piezoelectric thin film is used as the piezoelectric body, the piezoelectric thin film is provided on the insulating substrate film (A) by the above-described method, and an electrode pattern is further provided, followed by coating with the electrode substrate coating film (B). In addition, before coat | covering with the electrode substrate coating film (B), it can also coat | cover with the electrode substrate coating film (B), after laminating | stacking a piezoelectric thin film on an electrode pattern further.

  The surface on the side where the electrode pattern or piezoelectric thin film of the insulating substrate film (A) and electrode substrate covering film (B) used in the present invention is provided can be subjected to corona treatment or plasma treatment in order to improve adhesion. it can.

  Similarly, the surface of the piezoelectric thin film and the electrode pattern can be subjected to corona treatment or plasma treatment.

  In the present invention, the liquid level detection device refers to a device that senses and detects a liquid level in a container using a capacitance sensor or a pressure sensing sensor.

  When a capacitance sensor is used in the liquid level detection device, the capacitance at the liquid level at each electrode position is detected by the measurement electrode and the correction electrode and transmitted to each oscillator. In each oscillator, the liquid level can be sensed by converting the capacitance at each liquid level into a frequency and transmitting it to the liquid level calculation unit.

  When a pressure sensing sensor is used for the liquid level detection device, the liquid level can be sensed by sensing the pressure of the liquid in the container with the electrodes.

  In the present invention, a film made of a thermoplastic resin is used as the insulating substrate film (A) and the electrode substrate coating film (B). The thermoplastic resin film can be obtained by melt-extruding a thermoplastic resin, stretching in the longitudinal direction, or the width direction, or the longitudinal direction and the width direction, if necessary, and cooling and heat setting. As the thermoplastic resin, an insulating resin can be widely used. For example, vinyl chloride, polyethylene, polypropylene, polyester, polycarbonate, polyamide, polyetherimide, polyacetal, polysulfone, polyarylene sulfide, liquid crystal polymer, polyether ether ketone, etc. Can be given. Of these, polyarylene sulfide is preferably used from the viewpoints of heat resistance, chemical resistance, fuel resistance, and hydrolysis resistance.

  In the present invention, polyarylene sulfide is a homopolymer or copolymer having a repeating unit of-(Ar-S)-. Examples of Ar include structural units represented by the following formulas (A) to (K).

(R1 and R2 are substituents selected from hydrogen, an alkyl group, an alkoxy group, and a halogen group, and R1 and R2 may be the same or different.)
As the repeating unit of polyarylene sulfide used in the present invention, those represented by the above formula (A) are preferable, and typical examples thereof include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, and random copolymers thereof. Examples thereof include a polymer, a block copolymer and a mixture thereof. Particularly preferred polyarylene sulfides are preferably polyphenylene sulfide (PPS) from the viewpoint of film properties and economy, and preferably include 95 mol% of p-phenylene sulfide units represented by the following structural formula as the main structural unit of the polymer. As described above, it is desirable that the resin contains 97 mol% or more. When the p-phenylene sulfide component is less than 95 mol%, the crystallinity and thermal transition temperature of the polymer are low, and the heat resistance, dimensional stability, mechanical properties, dielectric properties, etc., which are the characteristics of PPS, may be impaired.

  In the PPS resin, if the repeating unit is less than 5 mol%, preferably less than 3 mol%, other units containing a copolymerizable sulfide bond may be contained. As the repeating unit of less than 5 mol%, preferably less than 3 mol% of the repeating unit, for example, a trifunctional unit, an ether unit, a sulfone unit, a ketone unit, a meta bond unit, a phenyl unit having a substituent such as an alkyl group, Examples include biphenyl units, terphenylene units, vinylene units, carbonate units, and the like, and specific examples include the following structural units. One or more of these can be used. In this case, the structural unit and the p-phenylene sulfide unit may be either a random copolymer type or a block copolymer type.

  The melt viscosity of the PPS resin and the PPS resin composition is not particularly limited as long as melt kneading is possible, but is in the range of 100 to 2000 PAS at a temperature of 315 ° C. and a shear rate of 1,000 (1 / sec). Preferably, it is in the range of 200 to 1,000 PAS.

  PPS can be obtained by various methods, for example, a method for obtaining a polymer having a relatively small molecular weight described in JP-B-45-3368, or JP-B-52-12240 and JP-A-61-7332. For example, a method for obtaining a polymer having a relatively large molecular weight.

  In the present invention, the obtained PPS resin is subjected to crosslinking / polymerization by heating in air, heat treatment under an inert gas atmosphere such as nitrogen or reduced pressure, washing with an organic solvent, hot water, an acid aqueous solution, etc., acid anhydride It can also be used after various treatments such as activation with functional group-containing compounds such as products, amines, isocyanates and functional group disulfide compounds.

  Next, although the manufacturing method of PPS resin is illustrated, in this invention, it is not limited to this in particular. For example, sodium sulfide and p-dichlorobenzene are reacted in an amide polar solvent such as N-methyl-2-pyrrolidone (NMP) at high temperature and high pressure. If necessary, a copolymer component such as trihalobenzene can be included. Caustic potash or alkali metal carboxylate is added as a polymerization degree adjusting agent, and a polymerization reaction is performed at 230 to 280 ° C. After the polymerization, the polymer is cooled, and the polymer is filtered as a water slurry through a filter to obtain a granular polymer. This is stirred in an aqueous solution such as acetate at 30 to 100 ° C. for 10 to 60 minutes, washed several times with ion exchange water at 30 to 80 ° C. and dried to obtain a PPS powder. The powder polymer is washed with NMP at an oxygen partial pressure of 10 torr or less, preferably 5 torr or less, then washed several times with ion-exchanged water at 30 to 80 ° C., and dried under a reduced pressure of 5 torr or less. Since the polymer thus obtained is a substantially linear PPS polymer, stable stretch film formation becomes possible. Of course, if necessary, other polymer compounds, inorganic and organic compounds such as silicon oxide, magnesium oxide, calcium carbonate, titanium oxide, aluminum oxide, crosslinked polyester, crosslinked polystyrene, mica, talc and kaolin and thermal decomposition inhibitors, You may add a heat stabilizer, antioxidant, etc. in the range which does not impair the effect of this invention.

  As a specific method for crosslinking / high molecular weight by heating PPS resin, under an oxidizing gas atmosphere such as air or oxygen or a mixed gas atmosphere of the oxidizing gas and an inert gas such as nitrogen or argon. A method of heating until a desired melt viscosity is obtained at a predetermined temperature in a heating container can be exemplified. The heat treatment temperature is usually selected from 170 to 280 ° C, more preferably from 200 to 270 ° C, and the heat treatment time is usually selected from 0.5 to 100 hours, more preferably from 2 to 50 hours. However, by controlling both of these, a target viscosity level can be obtained. The heat treatment apparatus may be a normal hot air dryer or a heating apparatus with a rotary type or a stirring blade, but in order to efficiently and uniformly perform the treatment, use a heating apparatus with a rotary type or a stirring blade. Is preferred.

  As a specific method for heat-treating the PPS resin under an inert gas atmosphere such as nitrogen or under reduced pressure, a heat treatment temperature of 150 to 280 ° C., preferably 200 to 200 ° C. under an inert gas atmosphere such as nitrogen or under reduced pressure. A method of heat treatment at 270 ° C. and a heating time of 0.5 to 100 hours, preferably 2 to 50 hours can be exemplified. The heat treatment apparatus may be a normal hot air drier or a heating apparatus with a rotary or stirring blade, but it is preferable to use a heating apparatus with a rotary or stirring blade for efficient and more uniform treatment. .

  The PPS resin used in the present invention is preferably a substantially linear PPS that does not undergo high molecular weight by thermal oxidation crosslinking treatment.

  The PPS resin used in the present invention is preferably a PPS resin that has been subjected to deionization treatment. Specific examples of the deionization treatment include an acid aqueous solution washing treatment, a hot water washing treatment, and an organic solvent washing treatment, and these treatments may be used in combination of two or more methods.

  The following method can be illustrated as a specific method for the organic solvent cleaning treatment of the PPS resin. That is, the organic solvent is not particularly limited as long as it does not have an action of decomposing the PPS resin. For example, nitrogen-containing polar solvents such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, Sulfoxide / sulfone solvents such as dimethylsulfone, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, ether solvents such as dimethyl ether, dipropyl ether, tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene chloride, dichloroethane, Halogen solvents such as tetrachloroethane, chlorobenzene, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, Phenol, cresol, alcohol phenol based solvents such as polyethylene glycol, benzene, and aromatic hydrocarbon solvents such as toluene and xylene. Among these organic solvents, N-methylpyrrolidone, acetone, dimethylformamide and chloroform are particularly preferably used. These organic solvents are used alone or in combination of two or more.

  As a method of washing with an organic solvent, there is a method of immersing a PPS resin in an organic solvent, and it is possible to appropriately stir or heat as necessary. There is no restriction | limiting in particular about the washing | cleaning temperature at the time of wash | cleaning PPS resin with an organic solvent, Arbitrary temperature can be selected in the range of normal temperature-300 degreeC. As the cleaning temperature increases, the cleaning efficiency tends to increase, but usually a sufficient effect is obtained at a temperature of room temperature to 150 ° C. The PPS resin that has been washed with an organic solvent is preferably washed several times with water or warm water in order to remove the remaining organic solvent.

  The following method can be illustrated as a specific method of the hot water washing process of PPS resin. That is, it is preferable that the water to be used is distilled water or deionized water in order to exhibit a preferable chemical modification effect of the PPS resin by hot water washing. The operation of the hot water treatment is usually performed by adding a predetermined amount of PPS resin to a predetermined amount of water, and heating and stirring at normal pressure or in a pressure vessel. The ratio of the PPS resin to water is preferably larger, but usually a bath ratio of 200 g or less of PPS resin is selected for 1 liter of water.

  The following method can be illustrated as a specific method of the acid aqueous solution washing treatment of the PPS resin. That is, there is a method of immersing the PPS resin in an acid or an acid aqueous solution, and it is possible to appropriately stir or heat as necessary. The acid to be used is not particularly limited as long as it does not have an action of decomposing PPS resin. For example, aliphatic saturated monocarboxylic acids such as formic acid, acetic acid, propionic acid and butyric acid, and halogen-substituted fatty acids such as chloroacetic acid and dichloroacetic acid. Saturated carboxylic acids, aliphatic unsaturated monocarboxylic acids such as acrylic acid and crotonic acid, aromatic carboxylic acids such as benzoic acid and salicylic acid, dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, phthalic acid and fumaric acid And inorganic acidic compounds such as sulfuric acid, phosphoric acid, hydrochloric acid, carbonic acid and silicic acid. Of these, acetic acid and hydrochloric acid are preferably used. It is preferable to wash the acid-treated PPS resin several times with water or warm water in order to remove the remaining acid or salt. The water used for washing is preferably distilled water or deionized water in the sense that the effect of the preferred chemical modification of the PPS resin is not impaired by the acid treatment.

  The polyarylene sulfide film is preferably a film obtained by melt-molding a resin composition containing 90% by weight or more of an arylene sulfide unit such as p-phenylene sulfide into a sheet, biaxially stretching, and heat treatment. When the content of the arylene sulfide unit such as p-phenylene sulfide is less than 90% by weight, the crystallinity as the composition is lowered, and the heat resistance, thermal dimensional stability, hydrolysis resistance, etc. of the film may be impaired. . When phenylene sulfide units are used as the polyarylene sulfide, less than 10% by weight in the composition can contain a polymer other than polyphenylene sulfide. Examples of polymers other than polyphenylene sulfide include various polymers such as polyamide, polyetherimide, polyethersulfone, polysulfone, polyphenylene ether, polyester, polyarylate, polyamideimide, polycarbonate, polyolefin, and polyetheretherketone, and at least of these polymers. Mention may be made of blends comprising one species. It can also contain additives such as inorganic or organic fillers, lubricants, colorants, ultraviolet absorbers, compatibilizers and the like.

  In the present invention, it is desirable to use copolymerized polyarylene sulfide (copolymerized PAS) as the thermoplastic resin in order to develop the adhesion between the insulating substrate film (A) and the electrode substrate coating film (B). The copolymer PAS used in the present invention is preferably composed of p-phenylene sulfide units as a main component, preferably 80 mol% or more and 92 mol% or less. If the p-phenylene sulfide unit is less than 80 mol%, the heat resistance of the film may be significantly reduced, and if it exceeds 92 mol%, the interfacial adhesion may not be sufficiently improved.

  As copolymerized units, m-phenylene sulfide units represented by the following formula,

(Here, X represents an alkylene, CO, or SO ₂ unit.)

(Wherein R represents an alkyl, nitro, phenylene, or alkoxy group), and these complex units may be present. Preferred copolymerized units are m-phenylene sulfide units. The copolymerization amount of these units is preferably 8 mol% or more and 20 mol% or less, more preferably 10 mol% or more and 18 mol% or less, and still more preferably 12 mol% or more and 15 mol% or less. When the copolymerization component is less than 8 mol%, the interfacial adhesion may not be sufficiently improved. When it exceeds 20 mol%, the heat resistance may be significantly lowered. The copolymerization mode of p-phenylene sulfide units and m-phenylene sulfide units is not particularly limited, but is preferably a random copolymer.

  In the present invention, the remaining part of the repeating unit of the copolymer constituting the copolymer polyarylene sulfide may be further composed of other copolymerizable structural units. For example, it is represented by the following formula: The trifunctional phenyl sulfide is preferably 1 mol% or less of the entire copolymer.

  The melting point of the copolymerized PAS is preferably 210 ° C. or higher and 260 ° C. or lower, more preferably 220 ° C. or higher and 250 ° C. or lower. When the melting point of the copolymerized PAS is less than 210 ° C., the heat resistance may be remarkably deteriorated, and when it exceeds 260 ° C., the interfacial adhesion may not be sufficiently improved. The melting point of the copolymerized PAS can be appropriately adjusted depending on the molar ratio of the copolymerized components. For example, when the melting point of copolymerized PAS is 210 ° C., it can be obtained by setting the molar ratio of m-phenylene sulfide units as a copolymerization component to 20 mol%.

  In the present invention, other sheet layers may be further laminated as necessary as long as the effects of the present invention are not hindered.

  In the present invention, it is desirable to use a copolymerized arylene sulfide laminated polyarylene sulfide film. For example, this film is formed by melt-molding the copolymerized polyarylene sulfide into a sheet, biaxially stretching, and heat-treating the film. It can be obtained as a film laminated on an arylene sulfide film.

  The method for laminating the copolymer polyarylene sulfide on the polyarylene sulfide film is not particularly limited, but a method by coextrusion or a method of laminating each film is preferably used.

  A method for producing a laminated film will be described. The polyarylene sulfide raw material and the copolymerized polyarylene sulfide raw material are supplied to separate melt-extrusion apparatuses and heated to the melting point of each raw material or higher. Each raw material melted by heating is laminated in two or three layers in a molten state by a merging device provided between the melt extrusion device and the die outlet, and is extruded from the slit-like die outlet. Such a molten laminate can be cooled on the cooling drum below the glass transition point of polyarylene sulfide to obtain a substantially amorphous two-layer or three-layer unstretched laminated film and then biaxially stretched. .

  Next, this unstretched laminated film is biaxially stretched and biaxially oriented. Stretching methods include sequential biaxial stretching methods (stretching methods that combine stretching in each direction, such as a method of stretching in the width direction after stretching in the longitudinal direction), and simultaneous biaxial stretching methods (in the longitudinal direction and the width direction). The method of extending | stretching simultaneously), or the method which combined them can be used.

  Here, a sequential biaxial stretching method in which stretching in the longitudinal direction and then in the width direction is performed first is used. The stretching temperature will be described below.

  The unstretched laminated film is heated with a heating roll group, and it is 2 to 4 times in the longitudinal direction, preferably 2.5 to 4 times, and more preferably 2.8 to 3.5 times in one or more stages. Stretch (MD stretching). The stretching temperature is Tg (where Tg represents the glass transition temperature of the film, and the glass transition temperature (Tg) to (Tg + 50) ° C., preferably (Tg + 5) to (Tg + 50) ° C. of the polymer exhibiting the highest glass transition temperature). More preferably, it is in the range of (Tg + 5) to (Tg + 40) ° C., more preferably in the range of (Tg + 10) to (Tg + 30) ° C. Most preferably, it is in the range of (Tg + 15) to (Tg + 30) ° C. Thereafter, 20 to 50 ° C. Cool with a group of cooling rolls.

  As a stretching method in the width direction following MD stretching, for example, a method using a tenter is common. The both ends of this film are gripped with clips, guided to a tenter, and stretched in the width direction (TD stretching). The stretching temperature is preferably Tg to (Tg + 60) ° C, more preferably (Tg + 5) to (Tg + 50) ° C, and still more preferably (Tg + 10) to (Tg + 40) ° C. In particular, the TD stretching is preferably performed at a low temperature of 3 to 15 ° C., more preferably 5 to 10 ° C. lower than the stretching temperature of the MD stretching. It is preferable to set the stretching temperature of TD stretching within a preferable range since it is possible to prevent excessive polycrystallization of polyarylene sulfide. Further, in the preheating zone before the stretching zone of TD stretching, it is preferable to carry out the preheating temperature at a temperature 3 to 10 ° C. lower than the temperature of TD stretching, and more preferably to a temperature 5 to 7 ° C. To do. It is preferable to set the preheating temperature before TD stretching within a preferable range, since it is possible to prevent excessive crystallization of polyarylene sulfide from proceeding. The draw ratio is preferably 2 to 4 times, more preferably 2.5 to 4 times, and still more preferably 2.8 to 3.5 times.

  Next, this stretched film is heat-set under tension or while relaxing in the width direction. A preferable heat setting temperature is 200 to 270 ° C, more preferably 210 to 260 ° C, and still more preferably 220 to 255 ° C. It is also preferable to carry out heat setting in two stages by changing the temperature. In that case, it is preferable to make the heat setting temperature of the second stage higher by 5 to 20 ° C. than the first stage. The heat setting time is preferably 0.2 to 30 seconds, and more preferably 5 to 20 seconds. Further, the film is cooled while relaxing in the width direction in a temperature zone of 40 to 180 ° C. The relaxation rate is preferably 1 to 10% from the viewpoint of reducing the thermal contraction rate in the width direction, more preferably 2 to 8%, and still more preferably 3 to 7%.

  Further, the film is cooled and rolled up to room temperature, if necessary, while relaxing in the longitudinal direction and / or the width direction, if necessary, to obtain the desired polyarylene sulfide film.

  The thickness of the copolymerized polyarylene sulfide film is preferably 50% or more when the height of the electrode is 1. If the thickness of the copolymerized PAS layer is less than 50% of the height of the electrode pattern, the electrode will collapse when the electrode is covered with the insulating substrate film (A) and the electrode substrate with the electrode substrate covering film (B). In some cases, voids or bubbles are formed between (A) and (B), resulting in a decrease in adhesion.

  The thickness of the polyarylene sulfide film of the present invention varies depending on the use and the like, but is preferably 500 μm or less, more preferably in the range of 10 to 300 μm, and still more preferably in the range of 20 to 200 μm.

  The polyarylene sulfide film may be subjected to any processing such as heat treatment, molding, surface treatment, laminating, coating, printing, embossing and etching, as necessary.

  The polyarylene sulfide film can be preferably used because the adhesiveness can be improved by subjecting it to thermal relaxation treatment once more after film formation.

  In the present invention, the electrode substrate is a film in which an electrode pattern is formed on an insulating substrate film (A) made of a thermoplastic resin film, or a piezoelectric thin film and an electrode pattern on an insulating substrate film (A) made of a thermoplastic resin film. Is what formed.

As a method of coating the electrode substrate with the electrode substrate coating film (B), a method of directly thermocompression bonding them under high temperature and high pressure without using an adhesive can be used. The method of thermocompression bonding is performed by a method using a heating roll or a hot plate press, but a method using a heating roll is preferable from the viewpoint of the production process. In addition, since the electrode substrate covering film (B) and the electrode substrate are heat-sealed (thermocompression bonding) immediately after heating the electrode substrate, the entire substrate can be heated uniformly at high temperature and cooled immediately after thermocompression bonding. This is preferable from the viewpoint of flatness. The time from the heating of the electrode substrate to the thermocompression bonding with the electrode substrate coating film (B) is preferably in the range of 1 to 60 seconds, the pressing pressure during thermocompression bonding is 1 to 500 kg / cm ² , and the pressing time is 1 to 120. Second, more preferably 5 to 60 seconds are preferred in terms of adhesion and maintaining the quality of the electrode substrate after thermocompression bonding (such as wrinkles and bubbles). The heating method for the electrode substrate is generally a hot air, an electric heater, or a heating roll method, and water or other media is generally used for cooling the press roll.

The thermocompression bonding conditions are as follows: when using a polyarylene sulfide film or a copolymerized arylene sulfide laminated polyarylene sulfide film as the insulating substrate film (A) and the electrode substrate coating film (B), the temperature is 180 ° C. to 320 ° C. and the pressure is 1 A condition of ˜500 kg / cm ² is preferable. If the temperature is less than 180 ° C., the adhesive strength may not be sufficiently increased, and if it exceeds 320 ° C., the planarity of the polyarylene sulfide film may be rapidly deteriorated and the mechanical properties may be deteriorated. On the other hand, if the pressure is less than 1 kg / cm ² , the adhesiveness is poor even if the temperature of thermocompression bonding is increased. Conversely, if the pressure exceeds 500 kg / cm ² , the planarity of the electrode substrate deteriorates or the polyarylene sulfide film is It may break. A more preferable thermocompression bonding temperature from the viewpoints of adhesiveness and mechanical properties is in the range of 200 ° C to 270 ° C, and more preferably in the range of 220 ° C to 260 ° C. On the other hand, the more preferable thermocompression bonding pressure is in the range of 5 to 400 kg / cm ² , and more preferably in the range of 10 to 300 kg / cm ² , but is not limited thereto.

    The characteristic value measurement method and effect evaluation method of the present invention are as follows.

(1) Glass transition temperature (Tg), melting temperature (Tm), heat of crystal melting Specific heat was measured by the pseudo-isothermal method under the following apparatus and conditions, and determined according to JIS K7121. The number of samples was measured for each sample, and the average value was taken.

Apparatus: Temperature modulation DSC manufactured by Seiko Instruments
Measurement condition:
Heating temperature: 270-570K (RCS cooling method)
Temperature calibration: Melting point of high purity indium and tin Temperature modulation amplitude: ± 1K
Temperature modulation period: 60 seconds Temperature rising step: 5K
Sample weight: 5mg
Sample container: Aluminum open container (22 mg)
Reference container: Aluminum open container (18mg)
The glass transition temperature (Tg) was calculated by the following formula.
Glass transition temperature = (extrapolated glass transition start temperature + extrapolated glass transition end temperature) / 2
In addition, using a Seiko Instruments DSC (RDC220) as the suggested scanning calorimeter and a disk station (SSC / 5200) manufactured by Seiko Instruments Inc. as a data analyzer, 5 mg of the sample was measured from room temperature to 340 on an aluminum pan. The temperature was increased to 20 ° C. at a rate of temperature increase of 20 ° C./min, and the heat quantity of the endothermic peak of melting observed was defined as the heat of crystal melting. Thereafter, the mixture was melt-held at 340 ° C. for 5 minutes, rapidly solidified, and then heated from room temperature at a rate of temperature increase of 20 ° C./min. At that time, the peak temperature of the endothermic peak of melting observed was defined as the melting temperature (Tm).
(2) Lamination thickness of copolymerized PAS laminated PAS film A microtome was used to cut a cross section in a direction perpendicular to the film surface, and then fixed to a sample stage of a scanning electron microscope. After performing a gold | metal sputter | spatter on the film cross section using a sputtering device, the cross section was observed by 2000 times magnification using the scanning electron microscope, and lamination | stacking thickness was measured.
(3) Formability of film electrode for sensor After cutting so that a cross-section in a direction perpendicular to the film surface of the film electrode for sensor appeared using a microtome, it was fixed to a sample stage of a scanning electron microscope. After sputtering the film cross section with a sputtering apparatus, the cross section was observed at a magnification of 5000 using a scanning electron microscope to confirm whether the electrodes were crushed or bubbles were present.

○ Electrode collapse and no bubbles △ Electrode collapse or bubbles × Electrode collapse and bubbles (4) Flexibility Wrap the sensor film electrode around a cylinder with a diameter of 5 cm, and connect the electrode substrate and electrode coating film (B). The presence or absence of cracks and peeling at the joint surface was judged visually.

◎ No crack or peeling ○ No crack or peeling on the observation surface 1 or less △ No crack or peeling on the observation surface 3 or less × Crack or peeling on the entire observation surface (5) Flatness Observe the surface of the sensor film electrode The presence or absence of wrinkles and undulations was judged visually.

◎ No wrinkles or waviness ○ Observation surface wrinkles or waviness 1 or less △ Observation surface wrinkles or waviness 3 or less × Wrinkles or waviness on entire observation surface (6) Chemical resistance of film electrode for sensor Sensor The film electrode was subjected to an immersion test in commercially available regular gasoline, 1N hydrochloric acid, and ethanol, and the presence or absence of peeling at the joint surface between the electrode substrate and the electrode coating film (B) was visually determined for the electrode after the test.

Immersion temperature: 40 ° C
Test period: 1000 hours ○ No delamination △ Partial delamination × Delamination on entire observation surface

Reference Example (1) Production of Copolymerized PPS Composition 100 mol of sodium sulfide nonahydrate, 45 mol of sodium acetate and 25 liters of N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) in an autoclave. Was gradually heated to a temperature of 220 ° C. while stirring, and the contained water was removed by distillation. In the system after dehydration, 5 liters of 91 mol of p-dichlorobenzene as a main component monomer, 10 mol of m-dichlorobenzene as a secondary component monomer, and 0.2 mol of 1,2,4-trichlorobenzene were added. Nitrogen was added together with NMP, and nitrogen was pressurized and sealed at 3 kg / cm ² at a temperature of 170 ° C. After completion of the polymerization, the mixture was cooled, the polymer was precipitated in distilled water, and a small block polymer was collected with a wire mesh having a 150 mesh opening. The small block polymer thus obtained was washed 5 times with distilled water at 90 ° C. and then dried at 120 ° C. under reduced pressure to obtain a white granular material having a melt viscosity of 1000 poise and a melting point of 253 ° C. A copolymerized PPS was obtained. Next, the obtained copolymer PPS was extruded into a gut shape at a temperature of 320 ° C. by a 30 mmφ twin screw extruder, and pelletized.
Reference Example (2) Production of PPS Composition All the same operations as in the production of the copolymerized PPS composition of the above (1) except that 101 mol of p-dichlorobenzene was used as the main component monomer and no subcomponent monomer was used. Thus, a PPS composition was produced. The PPS composition had a melt viscosity of 3000 poise and a melting point of 283 ° C.
Reference Example (3) Film Formation The copolymerized PPS composition and PPS composition obtained in Reference Examples (1) and (2) were each dried at a temperature of 180 ° C. for 3 hours under reduced pressure of 1 mmHg, and then separately. In the molten state, it is led into a double tube type laminating apparatus at the upper part of the die in the molten state so that it becomes 2 layers (Example 9 is 3 layers), and then discharged from the T-die die provided. Then, it was quenched with a cooling drum at a temperature of 25 ° C. to obtain a two-layer laminated sheet of a substantially amorphous copolymerized PPS composition / PPS composition. Next, each of the obtained laminated sheets was brought into contact with a plurality of heating rolls having a surface temperature of 95 ° C., and 3 ° in the longitudinal direction between 30 ° C. cooling rolls having different peripheral speeds provided next to the heating rolls. The film was stretched 5 times. The uniaxially stretched sheet thus obtained was stretched 3.5 times at a temperature of 100 ° C. in a direction perpendicular to the longitudinal direction using a tenter, and subsequently heat treated at a temperature of 255 ° C. for 10 seconds, and then rolled. And a copolymerized PPS laminated PPS film (a) to (d) having a thickness of 5 to 15 μm and having a thickness of 5 to 15 μm was obtained. The thickness configuration was changed by changing the discharge amount of the extruder of each layer.

(A) Copolymerization PPS composition lamination thickness 0.5 μm
(B) Copolymerized PPS composition laminate thickness 5 μm
(C) Copolymerized PPS composition lamination thickness 10 μm
(D) Copolymerization PPS composition lamination thickness 35 μm
A single PPS resin was separately formed and heat-treated according to the above film forming conditions to obtain a PPS film (e) having a thickness of 50 μm.

Reference Example (4) Thermal Relaxation Treatment The laminate film (c) obtained in Reference Example (3) was subjected to thermal relaxation treatment as follows using a suspended thermal relaxation apparatus.
After cutting off the tension on the film delivery side with a nip roller, the film is suspended under its own weight through a roller installed at the top while preheating to 90 ° C, heated to 200 ° C in the middle, and then almost horizontal with the lower roller. The direction was changed, the film was gradually cooled at an ambient temperature of 70 ° C., the winding tension was interrupted with a nip roller, and the film was wound up to obtain a heat relaxation treated PPS laminated film (f).
The tension between the upper and lower rollers was set to 20 kPa by installing a tension pickup in the processing section and adjusting the motor of each nip roller on the feeding / winding side.

(Examples 1-4)
Copper was laminated | stacked on the PPS film (e) obtained by the said film forming method using sputtering method, and it was set as the electrode substrate. At this time, the laminated thickness of copper was adjusted to 10 μm. The copper of this electrode substrate was coated with the copolymerized PPS laminated PPS films (a) to (d) obtained by the above film forming method, and after thermocompression bonding by a hot roll press method, immediately cooled to a temperature of 50 ° C. Thus, an electrode having the form shown in FIG. 1 was obtained. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to a linear pressure of 10 kg / cm ² .

  Table 1 shows the measurement and evaluation results for the structure and properties of the obtained film electrode for a capacitance sensor.

(Example 5)
Copper was laminated on the copolymerized PPS laminated PPS film (c) obtained by the above film forming method using a sputtering method to obtain an electrode substrate. At this time, the laminated thickness of copper was adjusted to 10 μm. The copper of this electrode substrate is covered with the PPS film (e) obtained by the above-mentioned film forming method, and after thermocompression bonding by a heated roll press method, immediately cooled to a temperature of 50 ° C. Got. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² .

  Table 1 shows the measurement and evaluation results for the structure and properties of the obtained film electrode for a capacitance sensor.

(Example 6)
Copper was laminated | stacked on the PPS film (e) obtained by the said film forming method using sputtering method, and it was set as the electrode substrate. At this time, the laminated thickness of copper was adjusted to 10 μm. The copper of this electrode substrate is covered with the PPS film (e) obtained by the above-mentioned film forming method, and after thermocompression bonding by a heated roll press method, immediately cooled to a temperature of 50 ° C. Got. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² .

Table 1 shows the measurement and evaluation results for the structure and properties of the obtained film electrode for a capacitance sensor.
(Example 7)
Copper was laminated | stacked on the PPS film (e) obtained by the said film forming method using sputtering method, and it was set as the electrode substrate. At this time, the laminated thickness of copper was adjusted to 10 μm. The copper of this electrode substrate was coated with the copolymerized PPS laminated PPS film (f) obtained by the above-mentioned film forming method, and after thermocompression bonding by a heated roll press method, immediately cooled to a temperature of 50 ° C. and shown in FIG. An electrode of the form shown was obtained. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² .

Table 1 shows the measurement and evaluation results for the structure and properties of the obtained film electrode for a capacitance sensor.
(Examples 8 to 11)
On the PPS film (e) obtained by the film forming method, lead zirconate titanate was laminated as a piezoelectric thin film using a sputtering method. At this time, the laminated thickness of the piezoelectric thin film was adjusted to 5 μm. Furthermore, copper was laminated on the piezoelectric thin film using a sputtering method to obtain an electrode substrate. At this time, the laminated thickness of copper was adjusted to 5 μm. The copper of this electrode substrate was coated with the copolymerized PPS laminated PPS films (a) to (d) obtained by the above film forming method, and after thermocompression bonding by a hot roll press method, immediately cooled to a temperature of 50 ° C. Thus, an electrode having the form shown in FIG. 2 was obtained. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² . Table 2 shows the measurement and evaluation results for the structure and properties of the obtained pressure-sensitive sensor film electrode.
Example 12
On the copolymerized PPS laminated PPS film (c) obtained by the film forming method, lead zirconate titanate was laminated as a piezoelectric thin film using a sputtering method. At this time, the laminated thickness of the piezoelectric thin film was adjusted to 5 μm. Furthermore, copper was laminated on the piezoelectric thin film using a sputtering method to obtain an electrode substrate. At this time, the laminated thickness of copper was adjusted to 5 μm. The electrode of the form shown in FIG. 2 is coated on the copper of this electrode substrate with the PPS film (e) obtained by the above-mentioned film forming method, and after thermocompression bonding by the heated roll press method, immediately cooled to a temperature of 50 ° C. Got. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² . Table 2 shows the measurement and evaluation results for the structure and properties of the obtained pressure-sensitive sensor film electrode.

(Example 13)
On the PPS film (e) obtained by the film forming method, lead zirconate titanate was laminated as a piezoelectric thin film using a sputtering method. At this time, the laminated thickness of the piezoelectric thin film was adjusted to 5 μm. Furthermore, copper was laminated on the piezoelectric thin film using a sputtering method to obtain an electrode substrate. At this time, the laminated thickness of copper was adjusted to 5 μm. The electrode of the form shown in FIG. 2 is coated on the copper of this electrode substrate with the PPS film (e) obtained by the above-mentioned film forming method, and after thermocompression bonding by the heated roll press method, immediately cooled to a temperature of 50 ° C. Got. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² . Table 2 shows the measurement and evaluation results for the structure and properties of the obtained pressure-sensitive sensor film electrode.
(Example 14)
On the PPS film (e) obtained by the film forming method, lead zirconate titanate was laminated as a piezoelectric thin film using a sputtering method. At this time, the laminated thickness of the piezoelectric thin film was adjusted to 5 μm. Furthermore, copper was laminated on the piezoelectric thin film using a sputtering method to obtain an electrode substrate. At this time, the laminated thickness of copper was adjusted to 5 μm. The copper on this electrode substrate was coated with the copolymerized PPS laminated PPS film (f) obtained by the above film forming method, and after thermocompression bonding by a heated roll press method, immediately cooled to a temperature of 50 ° C. and shown in FIG. An electrode of the form shown was obtained. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² . Table 2 shows the measurement and evaluation results for the structure and properties of the obtained pressure-sensitive sensor film electrode.
(Comparative Example 1)
Copper was laminated | stacked on the PPS film (e) obtained by the said film forming method using sputtering method, and it was set as the electrode substrate. At this time, the laminated thickness of copper was adjusted to 10 μm. An adhesive (cemedine Co., Ltd., epoxy resin-based elastic adhesive EP-001) was applied on the copper of this electrode substrate, and coated thereon with the PPS film (e) obtained by the above-mentioned film formation method, After thermocompression bonding by a heated roll press method, the electrode was immediately cooled to a temperature of 50 ° C. to obtain an electrode having the form shown in FIG. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² . Table 1 shows the measurement and evaluation results for the structure and properties of the obtained film electrode for a capacitance sensor.
(Comparative Example 2)
Copper was laminated | stacked on the PPS film (e) obtained by the said film forming method using sputtering method, and it was set as the electrode substrate. At this time, the laminated thickness of copper was adjusted to 10 μm. Copolymer PPS laminated PPS film (c) obtained by applying the adhesive (made by Cemedine Co., Ltd., epoxy resin-based elastic adhesive EP-001) on the copper of this electrode substrate, and obtained by the above-mentioned film forming method. After the thermocompression bonding by the heated roll press method, the electrode was immediately cooled to a temperature of 50 ° C. to obtain an electrode having the form shown in FIG. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² . Table 1 shows the measurement and evaluation results for the structure and properties of the obtained film electrode for a capacitance sensor.
(Comparative Example 3)
On the PPS film (e) obtained by the film forming method, lead zirconate titanate was laminated as a piezoelectric thin film using a sputtering method. At this time, the laminated thickness of the piezoelectric thin film was adjusted to 5 μm. Furthermore, copper was laminated on the piezoelectric thin film using a sputtering method to obtain an electrode substrate. At this time, the laminated thickness of copper was adjusted to 5 μm. An adhesive (cemedine Co., Ltd., epoxy resin-based elastic adhesive EP-001) was applied on the copper of this electrode substrate, and coated thereon with the PPS film (e) obtained by the above-mentioned film formation method, After thermocompression bonding by a heated roll press method, the electrode was immediately cooled to a temperature of 50 ° C. to obtain an electrode having the form shown in FIG. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² . Table 2 shows the measurement and evaluation results for the structure and properties of the film electrode for pressure-sensitive sensor obtained.
(Comparative Example 4)
On the PPS film (e) obtained by the film forming method, lead zirconate titanate was laminated as a piezoelectric thin film using a sputtering method. At this time, the laminated thickness of the piezoelectric thin film was adjusted to 5 μm. Furthermore, copper was laminated on the piezoelectric thin film using a sputtering method to obtain an electrode substrate. At this time, the laminated thickness of copper was adjusted to 5 μm. Copolymer PPS laminated PPS film (c) obtained by applying the adhesive (made by Cemedine Co., Ltd., epoxy resin-based elastic adhesive EP-001) on the copper of this electrode substrate, and obtained by the above-mentioned film forming method. After the thermocompression bonding by a heated roll press method, the electrode was immediately cooled to a temperature of 50 ° C. to obtain an electrode having the form shown in FIG. At this time, the heating press temperature was adjusted to 250 ° C., and the press pressure was adjusted to 10 kg / cm ² . Table 2 shows the measurement and evaluation results for the structure and properties of the obtained pressure-sensitive sensor film electrode.

  As described above, a film electrode for a sensor using the polyarylene sulfide film of the present invention as an insulating substrate film and an electrode substrate covering film can be suitably used as an electrode for a capacitance sensor, a pressure sensor, or the like.

It is sectional drawing which shows an example of the film electrode for electrostatic capacitance sensors by embodiment of this invention. It is sectional drawing which shows an example of the film electrode for pressure sensitive sensors by embodiment of this invention.

Explanation of symbols

1: Electrode substrate coating film 2: Metal electrode 3: Insulating substrate film 4: Piezoelectric thin film

Claims (8)

The film (A) made of a thermoplastic resin and the film (B) made of a thermoplastic resin are bonded together without using an adhesive, and the film (A) and the film (B) are bonded to each other. Is a film electrode for a sensor in which an electrode pattern is formed. The film electrode for sensors according to claim 1, wherein a polyarylene sulfide film is used as the film (A) and the film (B). The outermost layer on the film (B) surface side of the film (A) and / or the outermost layer on the film (A) surface side of the film (B) is composed of a copolymerized polyarylene sulfide. The film electrode for sensors as described. The outermost surface layer that is not the film (B) surface side of the film (A) and / or the outermost layer that is not the film (A) surface side of the film (B) is made of copolymerized polyarylene sulfide. The film electrode for sensors according to any one of the above. A method for producing a film electrode for a sensor, wherein an electrode pattern is formed on a film (A) made of a thermoplastic resin, and then a film (B) made of a thermoplastic resin is thermocompression bonded without using an adhesive. The electrostatic capacitance type sensor formed using the film electrode for sensors in any one of Claims 1-4. A pressure-sensitive sensor using the film electrode for a sensor according to claim 1. A liquid level detection apparatus using the sensor according to claim 6.

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