JP2010219483A - Organic piezoelectric material, ultrasonic vibrator, ultrasonic probe, and ultrasonic medical image diagnosis device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide organic piezoelectric materials which have superior piezoelectric characteristics and handling properties, and to provide an ultrasonic vibrator, an ultrasonic probe and an ultrasonic medical image diagnosis device using them. <P>SOLUTION: An organic piezoelectric material contains a polymer formed through polymerization reaction between: a macromonomer having at least two kinds of bonds, including one of a nitrogen atom, an oxygen atom and a sulfur atom; and polyurea. The glass transition temperature of the organic piezoelectric material is 100 to 180°C. The organic piezoelectric material has an electromechanical coupling constant of ≥0.20, and is used for the ultrasonic vibrator for reception by forming electrodes. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic piezoelectric material excellent in piezoelectric characteristics and handleability, an ultrasonic transducer using the same, an ultrasonic probe, and an ultrasonic medical diagnostic imaging apparatus.

  Ultrasonic probes are rapidly used as medical ultrasonic diagnostic apparatuses in addition to nondestructive inspection apparatuses. For example, a probe such as an ultrasonic endoscope radiates a high-frequency acoustic vibration from an ultrasonic transducer into a subject, receives the reflected ultrasonic wave by the ultrasonic transducer, and has a slight interface characteristic. A cross-sectional image inside the living body is obtained by processing different information depending on the difference.

  In recent years, harmonic imaging (Harmonic) that forms an image of the internal state of a subject by its harmonic frequency component, not by the frequency (fundamental frequency) component of the ultrasound transmitted from the ultrasound probe into the subject. Imaging technology is being researched and developed. In this harmonic imaging technique, (1) the side lobe level is smaller than the fundamental frequency component level, the S / N ratio (signal to noise ratio) is improved, and the contrast resolution is improved. Increasing the beam width narrows and the lateral resolution improves. (3) Multiple reflections are suppressed because the sound pressure is small and the fluctuation of the sound pressure is small at a short distance, and (4) It has various advantages such as a greater depth than the case where the attenuation beyond the focal point is the same as that of the fundamental wave and a high frequency is the fundamental wave, and enables highly accurate diagnosis (for example, Patent Document 1). reference).

In such an ultrasonic probe, a piezoelectric body that generates ultrasonic waves is used. Conventionally, as a piezoelectric body, a so-called inorganic material in which a single crystal such as quartz, LiNbO ₃ , LiTaO ₃ , or KNbO ₃ , a thin film such as ZnO or AlN, or a sintered body such as Pb (Zr, Ti) O ₃ is subjected to polarization treatment. Piezoelectric ceramics are widely used.

On the other hand, organic piezoelectric materials (also referred to as “piezoelectric polymer materials” or “polymer piezoelectric materials”) using organic polymer materials such as polyvinylidene fluoride (PVDF) and polyurea have been developed. (For example, refer to Patent Document 2). This organic piezoelectric body has greater flexibility than ceramics piezoelectric bodies, and can be easily made into any shape and form with a thin film, large area, and long length. small, hydrostatic voltage output coefficient (g _h constant) excellent sensitivity characteristics because very becomes larger, it is possible to further lower density, due to low elasticity, efficient energy propagation, having the properties and the like.

  However, the organic piezoelectric material has low heat resistance and loses its pyroelectric characteristics at high temperatures, and the physical properties such as elastic stiffness are greatly reduced, so that the usable temperature range is limited.

  In contrast to these limitations, polyurea resin compositions composed of urea bonds have a large dipole moment of urea bonds and are excellent in temperature characteristics as resins. Therefore, various studies have been made as organic piezoelectric materials. . For example, there is a so-called vapor deposition polymerization method in which a diisocyanate compound such as 4,4′-diphenylmethane diisocyanate (MDI) and a diamine compound such as 4,4′-diaminodiphenylmethane (MDA) are simultaneously evaporated to form a polyurea film. It is disclosed (see Patent Documents 3 and 4). However, the polyurea resin composition prepared by the vapor deposition polymerization method described in these documents has a non-uniform molecular weight of the oligomer or high molecular weight product. In this state, the polyurea resin composition is formed. For this reason, the dipole moment of the urea bond cannot be fully utilized, and further improvement has been demanded as an organic piezoelectric material.

  On the other hand, when a polyurea resin composition having a high degree of polymerization is synthesized by a solution polymerization method, since the resulting resin composition has a low elastic modulus and becomes a strong resin, improvements in film properties and handling properties are required. It was.

  However, in the case of polyurea, the hydrogen bond of the urea group is strong, so the solubility is very poor, and the rigidity is high, so that the handleability is extremely bad. However, there was a fault limited to the vapor deposition polymerization method.

Japanese Patent Laid-Open No. 11-276478 JP-A-6-216422 JP-A-2-284485 Japanese Patent Laid-Open No. 5-31399

  The present invention has been made in view of the above-mentioned problems and situations, and a problem to be solved is to provide an organic piezoelectric material excellent in piezoelectric characteristics and handleability. Furthermore, it is to provide an ultrasonic transducer, an ultrasonic probe, and an ultrasonic medical image diagnostic apparatus using them.

  The above-mentioned problem according to the present invention is solved by the following means.

  1. A polymer formed by a polymerization reaction of a macromonomer having at least two kinds of bonds containing any one of a nitrogen atom, an oxygen atom, and a sulfur atom and a polyurea, and having a glass transition temperature of 100 to 180 ° C An organic piezoelectric material comprising a polymer in the range of

  2. 2. The organic piezoelectric material as described in 1 above, wherein the polymer has an aliphatic ring in its main chain.

  3. 3. The organic piezoelectric material as described in 1 or 2 above, wherein at least one end of the chemical structure of the macromonomer is a polymerizable functional group.

  4). 4. The organic piezoelectric material according to any one of 1 to 3, wherein an electromechanical coupling constant of the organic piezoelectric material is 0.20 or more.

  5. 5. The organic piezoelectric material according to any one of 1 to 4, wherein the organic piezoelectric material is polarized by an electric field or a combination of an electric field and a magnetic field.

  6). 5. An ultrasonic transducer comprising the organic piezoelectric material according to any one of 1 to 4 and an electrode.

  7). An ultrasonic probe comprising the ultrasonic transducer described in 6 above.

  8). 8. The ultrasonic probe according to 7, wherein the ultrasonic transducer is a receiving ultrasonic transducer.

  9. An ultrasonic medical image diagnostic apparatus comprising the ultrasonic probe according to 7 or 8 above.

  By the above means of the present invention, an organic piezoelectric material excellent in piezoelectric characteristics and handleability can be provided. Furthermore, an ultrasonic transducer, an ultrasonic probe, and an ultrasonic medical image diagnostic apparatus using them can be provided.

  That is, from the viewpoint of the mechanism of action, it is important for the organic piezoelectric material to have a dipole orientation precisely, which is achieved by polarization treatment. From the viewpoint of an ultrasonic vibrator, stability over time and thermal stability are important, and thermal physical properties of the organic piezoelectric material are important. Since the vibrator generates heat up to 60 to 80 ° C. when driven, it is necessary to guarantee the quality of the material itself even if the material continues to be used at that temperature. By defining the glass transition temperature (Tg) of the piezoelectric material, it is possible to provide a more stable piezoelectric material.

  The lower the Tg, the higher the polarization treatment effect, but it is difficult to maintain the polarization (orientation) because the Tg is low. When the Tg of the material is designed so as to be 100 to 180 ° C. (or a material within this range is selected), a high polarization effect can be obtained and both thermal stability can be achieved.

The conceptual diagram which shows the structure of the principal part of an ultrasonic medical image diagnostic apparatus.

  The organic piezoelectric material of the present invention is a polymer formed by a polymerization reaction of a macromonomer having at least two types of bonds containing any one of a nitrogen atom, an oxygen atom, and a sulfur atom and a polyurea, A polymer having a glass transition temperature in the range of 100 to 180 ° C. is contained. This feature is a technical feature common to the inventions according to claims 1 to 9.

  As an embodiment of the present invention, from the viewpoint of the effect of the present invention, the polymer preferably has an aliphatic ring in its main chain. Moreover, it is preferable that at least one position of the terminal in the chemical structure of the macromonomer is a polymerizable functional group. Furthermore, the electromechanical coupling constant of the organic piezoelectric material is preferably 0.20 or more.

  In the present invention, the organic piezoelectric material is preferably subjected to a polarization treatment by an electric field or a combination of an electric field and a magnetic field.

  The organic piezoelectric material of the present invention can be suitably used for an ultrasonic vibrator. Further, the ultrasonic transducer can be suitably used for an ultrasonic probe. In this case, the ultrasonic transducer is preferably a receiving ultrasonic transducer.

  The ultrasonic probe can be suitably used for an ultrasonic medical image diagnostic apparatus.

Hereinafter, the present invention, its components, and the best mode and mode for carrying out the invention will be described in detail.
(Compound composing organic piezoelectric material)
The organic piezoelectric material of the present invention is a polymer formed by a polymerization reaction of a macromonomer having at least two types of bonds containing any one of a nitrogen atom, an oxygen atom, and a sulfur atom and a polyurea, A polymer having a glass transition temperature in the range of 100 to 180 ° C. is contained.

  Below, the compound which comprises the said organic piezoelectric material is demonstrated.

《Macromonomer》
In the present application, the “macromonomer” has a polymerizable functional group such as an isocyanate group, a group having active hydrogen, or a vinyl group at least at one end of the molecular chain, and a urea bond (—NR ₁ CONR ₂ —), thiourea bond (—NR ₁ CSNR ₂ —), urethane bond (—OCONR ₁ —), thiourethane bond (—SCONR ₁ —), ester bond (—COO—), thioester bond (—COS—) , Ether bond (—O—), sulfide bond (—S—), amide bond (—CONR ₁ —), thioamide bond (—CSNR ₁ —), sulfonamide bond (—SO ₂ NR ₁ —), sulfone diamide bond _{(-NR 1 SO 2 NR 2 -} ) and have to a carbonate bond (-OCOO-) a compound having two or more bonds selected from .

  In the present application, “a bond including any one of a nitrogen atom, an oxygen atom, and a sulfur atom” means a urea bond, a thiourea bond, a urethane bond, a thiourethane bond, an ester bond, a thioester bond, and an ether bond. , At least a bond selected from a sulfide bond, an amide bond, a thioamide bond, a sulfonamide bond, a sulfone diamide bond or a carbonate bond.

  In the present invention, it is preferable that at least one end of the chemical structure of the macromonomer is a polymerizable functional group. Here, the “polymerizable functional group” is a functional group selected from an isocyanate group, an isothiocyanate group, an active hydrogen group, a vinyl group, an acryloyl group, and a methacryloyl group.

In the present application, R ₁ and R ₂ in “urethane bond, thiourethane bond, amide bond, thioamide bond” are a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group). , A tert-butyl group, a pentyl group, a hexyl group, a cyclohexyl group and the like, preferably a hydrogen atom or an alkyl group having 5 or less carbon atoms, and more preferably a hydrogen atom or a methyl group.

  The macromonomer according to the present invention preferably has a urea bond, thiourea bond or sulfondiamide bond having a large dipole moment. That is, since the macromonomer according to the present invention can introduce a plurality of bonds and linking groups having a dipole moment by sequentially condensing a monomer having a reactive group, a resin composition that has been difficult in the past. It is possible to adjust the solubility and rigidity of the material by selecting the raw material. Moreover, since the influence of the residual monomer can be eliminated by using the macromonomer as a raw material, the heat resistance and piezoelectric characteristics as the piezoelectric material can be remarkably improved.

The “urea bond” is represented by the general formula: —NR ₁ CONR ₂ —. The “thiourea bond” is represented by the general formula: —NR ₁ CSNR ₂ —. The “sulfone diamide bond” is represented by the general formula: —NR ₁ SO ₂ NR ₂ —.

Here, R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, cyclohexyl group). Etc., preferably a hydrogen atom or an alkyl group having 5 or less carbon atoms, more preferably a hydrogen atom or a methyl group.

  The urea bond or thiourea bond may be formed by any means, but can be obtained by a reaction of an isocyanate and an amine or an isothiocyanate and an amine. Also, 1,3-bis (2-aminoethyl) urea, 1,3-bis (2-hydroxyethyl) urea, 1,3-bis (2-hydroxypropyl) urea, 1,3-bis (2-hydroxy) Methyl) thiourea, 1,3-bis (2-hydroxyethyl) thiourea, 1,3-bis (2-hydroxypropyl) thiourea, and the like substituted with an alkyl group having a hydroxyl group or an amino group at the terminal A macromonomer may be synthesized using a compound as a raw material.

  The isocyanate or isothiocyanate (hereinafter referred to as iso (thio) cyanate) used as a raw material is not particularly limited as long as it is a polyiso (thio) cyanate having two or more iso (thio) cyanate groups in the molecule. Iso (thio) cyanate or aromatic polyiso (thio) cyanate is preferred, and alkyl diiso (thio) cyanate or aromatic diiso (thio) cyanate is more preferred. Moreover, you may use asymmetrical diiso (thio) cyanate (for example, p-isocyanate benzyl isocyanate etc.) together as a raw material.

  Alkyl polyiso (thio) cyanate is a compound in which a plurality of iso (thio) cyanate groups are all present via an alkyl chain, such as 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate. , Trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 1,3-cyclopentane diisocyanate, pentamethylene diisothiocyanate and the like.

  The aromatic polyiso (thio) cyanate is a compound in which a plurality of iso (thio) cyanate groups are all directly bonded to an aromatic ring. For example, 9H-fluorene-2,7-diisocyanate, 9H-fluorene-9 -One-2,7-diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, 1, 3-bis (isocyanatomethyl) cyclohexane, 2,2-bis (4-isocyanatophenyl) hexafluoropropane, 1,5-diisocyanatonaphthalene, 2,6-tolylene isothiocyanate, 4,4'-diphenylmethane Examples include diisothiocyanate.

  The amine used as a raw material is preferably a polyamine having two or more amino groups in the molecule, and most preferably a diamine. Examples of polyamines include 2,7-diamino-9H-fluorene, 3,6-diaminoacridine, acriflavine, acridine yellow, 2,2-bis (4-aminophenyl) hexafluoropropane, and 4,4'-diaminobenzophenone. Bis (4-aminophenyl) sulfone, 4,4′-diaminodiphenyl ether, bis (4-aminophenyl) sulfide, 1,1-bis (4-aminophenyl) cyclohexane, 4,4′-diaminodiphenylmethane, 3, 3'-diaminodiphenylmethane, 3,3'-diaminobenzophenone, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4- (phenyldiazenyl) benzene-1,3-diamine, 1,5-diaminonaphthalene, 1,3-phenylenediamine, 2,4-diamy Toluene, 2,6-diaminotoluene, 1,8-diaminonaphthalene, 1,3-diaminopropane, 1,3-diaminopentane, 2,2-dimethyl-1,3-propanediamine, 1,5-diaminopentane, 2-methyl-1,5-diaminopentane, 1,7-diaminoheptane, N, N-bis (3-aminopropyl) methylamine, 1,3-diamino-2-propanol, diethylene glycol bis (3-aminopropyl) Ether, m-xylylenediamine, tetraethylenepentamine, 1,3-bis (aminomethyl) cyclohexane, benzoguanamine, 2,4-diamino-1,3,5-triazine, 2,4-diamino-6-methyl- 1,3,5-triazine, 6-chloro-2,4-diaminopyrimidine, 2-chloro-4,6-diamidine 1,3,5-triazine. These polyamines may be reacted with phosgene, triphosgene or thiophosgene to synthesize polyiso (thio) cyanate and used as a macromonomer raw material, or these polyamines may be used as chain extenders.

  When synthesizing a macromonomer, it is possible to synthesize a macromonomer having a high degree of order by utilizing the difference in reactivity between an amino group and a hydroxyl group. For this reason, the macromonomer preferably has at least one urethane bond or thiourethane bond. A urethane bond can be obtained by a reaction between a hydroxyl group and an isocyanate group, and a thiourethane bond can be obtained by a reaction between a thiol group and an isocyanate group. And alkylaminophenol. A polyol or an amino alcohol is preferable, and an amino alcohol is more preferable. Examples of the compound having a thiol group include polythiol, amino mercaptan, aminothiophenol, and alkylaminothiophenol. Preferred is polythiol or amino mercaptan, and more preferred is amino mercaptan.

  The polyol is a compound having at least two hydroxyl groups in the molecule, and preferably a diol. Examples of the polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedi Methanol, pentaerythritol, 3-methyl-1,5-pentanediol, poly (ethylene adipate), poly (diethylene adipate), poly (propylene adipate), poly (tetramethylene adipate), poly (hexamethylene adipate), poly ( Neopentylene adipate) and the like.

  Aminoalcohol is a compound having an amino group and a hydroxyl group in the molecule, such as aminoethanol, 3-amino-1-propanol, 2- (2-aminoethoxy) ethanol, 2-amino-1,3-propane. Examples include diol, 2-amino-2-methyl-1,3-propanediol, and 1,3-diamino-2-propanol. These compounds having a hydroxyl group may be used as a chain extender.

  Polythiol is a compound having at least two or more thiol groups in the molecule, and is preferably dithiol. Examples of the polythiol include 1,2-ethanedithiol, 1,3-propanedithiol, 1,2-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 3,7 -Dithia-1,9-nonanedithiol, 1,4-cyclohexanedimethylmercaptan and the like can be mentioned.

  Amino mercaptan is a compound having an amino group and a thiol group in the molecule. For example, 2-aminoethanethiol, 3-amino-1-propanethiol, 2- (2-aminoethoxy) ethanethiol, 2-amino- Examples include 1,3-propanedithiol, 2-amino-2-methyl-1,3-propanedithiol, 1,3-diamino-2-propanethiol, and the like. These compounds having a thiol group may be used as a chain extender.

  The macromonomer has a molecular weight of 400 to 10,000, but may have a molecular weight distribution because a dimer or a trimer is generated at the stage of sequential synthesis. The molecular weight is a weight average molecular weight obtained by measurement of gel permeation chromatography (hereinafter referred to as “GPC”), preferably 400 to 5000, and more preferably 400 to 3000. The molecular weight distribution is preferably 1.0 to 6.0, more preferably 1.0 to 4.0, and particularly preferably 1.0 to 3.0.

  In addition, the measurement of molecular weight and molecular weight distribution can be performed based on the following method and conditions.

Solvent: 30 mM LiBr in N-methylpyrrolidone Device: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgel SuperAWM-H x 2 (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Sample concentration: 1.0 g / L
Injection volume: 40 μl
Flow rate: 0.5 ml / min
Calibration curve: Standard polystyrene: PS-1 (manufactured by Polymer Laboratories) Mw = 580 to 2,560,000 calibration curves with 9 samples were used.

  In the present invention, since a resin composition having piezoelectric characteristics is obtained by polymerizing the macromonomer, at least one of the macromonomer terminals is an isocyanate group, a group having active hydrogen, a vinyl group, an acryloyl group, or a meta group. An acryloyl group is preferred. Examples of the group having active hydrogen include an amino group, a hydroxyl group, a carboxyl group, an imino group, and a thiol group, preferably an amino group, a hydroxyl group, or a carboxyl group, and more preferably an amino group or a hydroxyl group. It is.

  In order to improve the orientation of the macromonomer or polymerized resin composition, it is preferable to have an aliphatic ring in the main chain as a partial structure of the macromonomer.

  Preferred aliphatic rings include aliphatic rings having the following structure. The present invention is not limited to this. An asterisk (*) represents a point of attachment.

《Synthesis of macromonomer》
The macromonomer is a method in which a compound having active hydrogen is used as a starting material, and a polyiso (thio) cyanate and a compound having active hydrogen are alternately condensed, and a compound having active hydrogen having a polyiso (thio) cyanate as a starting material Polyiso (thio) cyanate can be synthesized by a method of alternately condensing.

  The compound having active hydrogen is the urea compound substituted with an alkyl group having a hydroxyl group, thiol group or amino group at the terminal, polyamine, polyol, polythiol, aminoalcohol, aminomercaptan, aminophenol, aminothio, as mentioned above. Phenol, alkylaminophenol, alkylaminothiophenol and the like can be mentioned. As a starting material, a urea compound or polyamine substituted with an alkyl group having a hydroxyl group or an amino group at a terminal is preferable, and a polyamine having an aromatic condensed ring structure is more preferable. When used in the step of alternately condensing, amino alcohol or polyol is preferable.

  When polyiso (thio) cyanate is used as a starting material, the starting material is preferably a polyiso (thio) cyanate having an aromatic condensed ring structure. A compound having active hydrogen at the terminal may be synthesized by condensing with a compound having active hydrogen, or a diamine may be formed by the method described in JP-A No. 5-115842.

  In addition, by reacting 3-chloro-1-butene, allyl chloride, acryloyl chloride or methacryloyl chloride with a macromonomer having active hydrogen at the terminal, a macro having a vinyl group, acryloyl group or methacryloyl group at the terminal Monomers can be synthesized.

  In the reaction of a compound having active hydrogen with polyiso (thio) cyanate, when at least one terminal is an isocyanate group, the amount of polyiso (thio) cyanate used for the compound having active hydrogen is 1 to 10 moles. Preferably, it is 1 to 5 times mole, more preferably 1 to 3 times mole.

  In the reaction of the compound having active hydrogen with polyiso (thio) cyanate, when at least one of the terminals is active hydrogen, the compound having active hydrogen is used in an amount of 1 to 10 moles relative to polyiso (thio) cyanate. Preferably, it is 1 to 5 times mole, more preferably 1 to 3 times mole.

  The reaction temperature to be condensed is preferably as low as possible, and is −40 to 60 ° C., preferably −20 to 30 ° C., and more preferably −10 to 10 ° C. The reaction temperature may be a constant temperature from the start to the end of the reaction, or may be initially low and then increased.

  As the solvent used for the reaction, it is necessary to use a highly polar solvent in order that the target resin composition is highly polar and the polymerization proceeds efficiently. For example, it is preferable to select a highly polar aprotic solvent such as DMF (N, N-dimethylformamide), DMAc (N, N-dimethylacetamide), DMSO (dimethylsulfoxide), NMP (N-methylpyrrolidone), As long as the reaction substrate and target compound dissolve well, aliphatic hydrocarbons such as cyclohexane, pentane and hexane, aromatic hydrocarbons such as benzene, toluene and chlorobenzene, THF (tetrahydrofuran), diethyl ether, ethylene glycol diethyl It may be a solvent such as ethers such as ether, ketones such as acetone, methyl ethyl ketone, 4-methyl-2-pentanone, esters such as methyl propionate, ethyl acetate, butyl acetate, etc. May be.

  Tertiary alkylamines such as N, N, N ′, N′-tetramethyl-1,3-butanediamine, triethylamine, tributylamine, etc. in order to efficiently generate urethane bonds or thiourethane bonds, 1,4 -Condensed amines such as diazabicyclo [2.2.2] octane and 1,8-diazabicyclo [5.4.0] unde-7-ene, and alkyltins such as DBTL, tetrabutyltin and tributyltin acetate, etc. The urethane bond-forming catalyst can be used.

  The amount of the catalyst used is preferably 0.1 to 30 mol% based on the monomer substrate in consideration of efficient reaction and reaction operation.

  The macromonomer may be isolated for each condensation step or synthesized in one pot, but it is preferable to perform isolation and purification at the time of forming a compound having a terminal active hydrogen.

  The macromonomer may be purified by any means, but purification by reprecipitation is preferred. The reprecipitation method is not particularly limited, but a method in which the macromonomer is dissolved in a good solvent and then dropped into a poor solvent to cause precipitation is preferable.

  As used herein, the “good solvent” may be any solvent as long as the macromonomer dissolves, but is preferably a polar solvent, specifically, DMF (N, N-dimethylformamide), DMAc. Examples thereof include highly polar aprotic solvents such as (N, N-dimethylacetamide), DMSO (dimethyl sulfoxide), and NMP (N-methylpyrrolidone).

  The “poor solvent” may be any solvent as long as it does not dissolve the macromonomer, but is an aliphatic hydrocarbon such as cyclohexane, pentane or hexane, or an aromatic hydrocarbon such as benzene, toluene or chlorobenzene. And ethers such as diethyl ether and ethylene glycol diethyl ether, esters such as methyl propionate, ethyl acetate and butyl acetate, and alcohols such as methanol, ethanol and propanol.

  Although the specific example of a macromonomer is given to the following, this invention is not limited to this.

  In the present invention, in addition to the macromonomer having an aliphatic ring in the main chain, the following macromonomer may be used in combination.

<Synthesis example of macromonomer>
[Synthesis Example 1: Synthesis of Macromonomer (A-2)]
Under a nitrogen atmosphere, 1,3-di (thiophen-2-yl) -4,5,6,7-tetrahydrobenzo [c] thiophene-5,6-diamine 33.3 g, 3-mercaptopropylamine 18.2 g, 17.8 g of triethylamine was dissolved in 500 ml of THF, and 27.0 g of sulfuryl chloride was slowly added dropwise at 0 ° C. After completion of dropping, the mixture was stirred at 0 ° C. for 1 hour, and further stirred at room temperature for 2 hours. After the solvent in the reaction solution was distilled off by 2/3 by vacuum concentration, reprecipitation was performed using a mixed solvent of ethyl acetate-heptane, and the supernatant was removed by decantation, followed by drying under reduced pressure. Thereafter, the resultant was dissolved in 100 ml of THF, dropped in a solution of 25.2 g of 1,3-propanediisocyanate in 500 ml of THF at 0 ° C., stirred at 0 ° C. for 1 hour, and further stirred at room temperature for 2 hours. Thereafter, it was dried under reduced pressure to obtain 85.7 g of A-2 intermediate 1. On the other hand, 28.4 g of 1,3-bis (aminomethyl) cyclohexane and 17.8 g of triethylamine were dissolved in 500 ml of THF, and 18.1 g of acryloyl chloride was added dropwise at 0 ° C. After completion of dropping, the mixture was stirred at 0 ° C. for 1 hour, and further stirred at room temperature for 2 hours. The solvent in the reaction solution was distilled off by 2/3 by vacuum concentration, and then reprecipitated using a mixed solvent of ethyl acetate-heptane. The supernatant was removed by decantation, followed by drying under reduced pressure to obtain A-2 intermediate 2 40.7g was obtained. Then, A-2 intermediate 2 dissolved in 200 ml of THF was added dropwise at 0 ° C. to A-2 intermediate 1 dissolved in 300 ml of THF, and reacted at room temperature for 3 hours. After the solvent in the reaction solution was distilled off by 2/3 by concentration under reduced pressure, the mixture was reprecipitated using a mixed solvent of ethyl acetate-heptane, the supernatant was removed by decantation, and the residue was dried under reduced pressure. 8 g was obtained. 1H-NMR confirmed the target product.

[Synthesis Example 2: Synthesis of Macromonomer (A-14)]
Under a nitrogen atmosphere, 19.8 g of 4,4-methylenedianiline was dissolved in 200 ml of THF, and a solution of 33.2 g of 1,3-cyclohexane diisocyanate dissolved in 100 ml of THF was slowly added dropwise at 0 ° C. After completion of dropping, the mixture was stirred at 0 ° C. for 1 hour, and further stirred at room temperature for 2 hours. Subsequently, the mixture was cooled to 0 ° C., 15.0 g of 3-amino-1-propanol was added dropwise, stirred at 0 ° C. for 1 hour, and further stirred at room temperature for 2 hours. After the solvent in the reaction solution was distilled off by 2/3 by vacuum concentration, reprecipitation was performed using a mixed solvent of ethyl acetate-heptane, and the supernatant was removed by decantation, followed by drying under reduced pressure. Thereafter, it was dissolved in 300 ml of THF, 32.0 g of 1,3-diisocyanatobenzene dissolved in 150 ml of THF was added dropwise at 0 ° C., stirred for 1 hour at 0 ° C., and further stirred for 2 hours at room temperature. After the solvent in the reaction solution was distilled off by 2/3 by vacuum concentration, reprecipitation was performed using a mixed solvent of ethyl acetate-heptane, and the supernatant was removed by decantation, followed by drying under reduced pressure. 1 g was obtained. 1H-NMR confirmed the target product.

[Synthesis Example 3: Synthesis of Macromonomer (A-26)]
Under a nitrogen atmosphere, 26.2 g of 4,4′-methylenebis (isocyanatocyclohexane) was dissolved in 200 ml of THF, and a solution of 20.5 g of tert-butyl 2- (2-hydroxyethyl) ethylcarbamate dissolved in 100 ml of THF was added at 0 ° C. It was dripped slowly. After completion of dropping, the mixture was stirred at 0 ° C. for 1 hour, and further stirred at room temperature for 2 hours. Subsequently, the mixture was cooled to 0 ° C., 10.6 g of diethylene glycol was added dropwise, stirred at 0 ° C. for 1 hour, and further stirred at room temperature for 2 hours. Thereafter, the mixture was cooled to 0 ° C., mixed with 5.0 g of trifluoroacetic acid, and reacted for 2 hours. After the solvent in the reaction solution was distilled off by 2/3 by vacuum concentration, reprecipitation was performed using a mixed solvent of ethyl acetate-heptane, and the supernatant was removed by decantation, followed by drying under reduced pressure. 45.1g of A-26 was obtained. 1H-NMR confirmed the target product.

[Synthesis Example 4: Synthesis of Macromonomer (M-8)]
Under a nitrogen atmosphere, 85.27 g of 9H-fluorene-2,7-diisocyanate was dissolved in 850 ml of THF, and 5.0 g of 2-chloro-4,6-diamino-1,3,5-triazine was dissolved in 50 ml of THF at 0 ° C. Slowly dropped. After completion of dropping, the mixture was stirred at 0 ° C. for 1 hour, and further stirred at room temperature for 2 hours. After the solvent in the reaction solution was distilled off by 2/3 by vacuum concentration, reprecipitation was performed using a mixed solvent of ethyl acetate-heptane, and the supernatant was removed by decantation, followed by drying under reduced pressure to obtain a macromonomer (M 20.0 g of -8) was obtained. 1H-NMR confirmed the target product.

[Synthesis Example 5: Synthesis of Macromonomer (M-15)]
40 g of diethylamine and 50 ml of THF were mixed, and 20 g of 9H-fluorene-2,7-diisocyanate dissolved in 50 ml of THF was added dropwise at room temperature. After completion of the dropwise addition, the mixture was stirred at room temperature for 1 hour, and then the precipitate was collected by filtration and washed with THF.

  Subsequently, 30 g of the obtained compound and 180 g of 2,2-dimethyl-1,3-propanediamine were mixed and heated at 120 ° C. The distillate was removed, and when the distillate disappeared, distillation under reduced pressure was performed under reduced pressure until the distillate disappeared. The obtained residue was washed with THF and sufficiently dried to obtain 1,1 ′-(9H-fluorene-2,7-diyl) bis (3- (3-amino-2,2-dimethylpropyl) urea. )

  Under a nitrogen atmosphere, 7 g of p-isocyanate benzyl isocyanate was dissolved in 70 ml of dimethyl sulfoxide, and the reaction solution was cooled to 0 ° C. After slowly dropping 3 g of 1,1 ′-(9H-fluorene-2,7-diyl) bis (3- (3-amino-2,2-dimethylpropyl) urea) dissolved in 30 ml of dimethyl sulfoxide The mixture was stirred at 0 ° C. for 1 hour. After gradually raising the temperature and reacting at room temperature for 1 hour, reprecipitation was performed using ethyl acetate. After removing the supernatant with decant, 6.5 g of macromonomer (M-15) was obtained by drying under reduced pressure. The weight average molecular weight by GPC measurement was 810, and molecular weight distribution was 1.6.

[Synthesis Example 6: Synthesis of Macromonomer (M-31)]
Under nitrogen atmosphere, 5.0 g of 9H-fluorene-2,7-diisocyanate was dissolved in 50 ml of THF, and 3.2 g of 3-aminopropanol dissolved in 30 ml of THF was slowly added dropwise at 0 ° C. After completion of dropping, the mixture was stirred at 0 ° C. for 1 hour to obtain a solution (A).

  13.0 g of 1,3-phenylene diisocyanate was dissolved in 65 ml of THF, and the solution (A) was added dropwise while heating the reaction solution to 70 ° C. After completion of the dropwise addition, the mixture was stirred at 70 ° C. for 5 hours, and then the solvent amount of the reaction solution was concentrated to 3/2 under reduced pressure. A mixed solution of ethyl acetate-heptane was added to the residue and stirred, and the supernatant was removed by decantation and dried under reduced pressure to obtain 12.5 g of a macromonomer (M-31). The weight average molecular weight by GPC measurement was 750, and molecular weight distribution was 2.0.

[Synthesis Example 7: Synthesis of Macromonomer (M-35)]
Under nitrogen atmosphere, 5.0 g of 9H-fluorene-2,7-diisocyanate was dissolved in 50 ml of THF, and 10.0 g of 2- (2-aminoethoxy) ethanol dissolved in 30 ml of THF at room temperature was slowly added dropwise. After completion of dropping, the mixture was stirred at room temperature for 3 hours. The residue was concentrated and then recrystallized to obtain 9.2 g of a macromonomer (M-35). 1H-NMR confirmed the target product.

  As the organic polymer material (hereinafter also referred to as “polymer material”) as a constituent material of the organic piezoelectric material of the present invention, various organic polymer materials that have been conventionally used as piezoelectric materials can also be used. . That is, an embodiment in which the organic piezoelectric material of the present invention is formed of a polymer material containing polyvinylidene fluoride as a main component or a composite material containing a polymer material containing polyvinylidene fluoride as a main component is also preferable.

  For example, as a typical material, an organic polymer material containing vinylidene fluoride as a main component can be used from the viewpoints of good piezoelectric characteristics, availability, and the like.

Specifically, it is preferably a homopolymer of polyvinylidene fluoride having a CF ₂ group having a large dipole moment or a copolymer having vinylidene fluoride as a main component.

  In addition, tetrafluoroethylene, trifluoroethylene, hexafluoropropane, chlorofluoroethylene, etc. can be used as the second component in the copolymer.

  For example, in the case of vinylidene fluoride / trifluoride ethylene copolymer, since the electromechanical coupling constant (piezoelectric effect) in the thickness direction varies depending on the copolymerization ratio, the former copolymerization ratio is 60 to 99 mol%. Furthermore, it is preferable that it is 70-95 mol%.

  A polymer containing 70 to 95 mol% of vinylidene fluoride and 5 to 30 mol% of perfluoroalkyl vinyl ether, perfluoroalkoxyethylene, perfluorohexaethylene, etc. is composed of an inorganic piezoelectric element for transmission and an organic piezoelectric element for reception. In combination with the element, it is possible to suppress the transmission fundamental wave and increase the sensitivity of harmonic reception.

  The polymer piezoelectric material is characterized in that it can be formed into a thin film as compared with an inorganic piezoelectric material made of ceramics, so that it can be used as a vibrator corresponding to transmission and reception of higher frequencies.

"solvent"
As the solvent that can be used in the polymerization in the present invention, solvents generally used for polymer material synthesis can be used, and examples include tetrahydrofuran, acetone, methyl ethyl ketone, ethyl acetate, methylene chloride, chloroform, toluene, hexane, and the like. However, this is not the case.

(Polyurea)
The organic piezoelectric material of the present invention is composed of a polymer formed by a polymerization reaction of the macromonomer having at least two types of bonds containing any one of a nitrogen atom, an oxygen atom, and a sulfur atom and a polyurea. It is characterized by that.

  The preferred polyurea used in the present invention is preferably a polyurea having a structure represented by the following general formula (UP1).

  <Polyurea having a structure represented by the general formula (UP1)>

In the general formula (UP1), R ₁ and R ₂ each independently represents an alkylene group, an arylene group, or a heteroarylene group. X represents an oxygen atom or a sulfur atom. R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, if R ₃ and R ₄ do not simultaneously hydrogen atoms is excluded.

  Examples of the alkylene group include methylene group, ethylene group, trimethylene group, tetramethylene group, propylene group, ethylethylene group, pentamethylene group, hexamethylene group, 2,2,4-trimethylhexamethylene group, heptamethylene group, Octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, cyclohexylene group (for example, 1,6-cyclohexanediyl group, etc.), cyclopentylene group (for example, 1,5-cyclopentanediyl group) Etc.).

  Examples of the arylene group include an o-phenylene group, m-phenylene group, p-phenylene group, naphthalenediyl group, anthracenediyl group, naphthacenediyl group, pyrenediyl group, naphthylnaphthalenediyl group, and biphenyldiyl group (for example, 3,3′- Biphenyldiyl group, 3,6-biphenyldiyl group, etc.), terphenyldiyl group, quaterphenyldiyl group, kinkphenyldiyl group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group Group, deciphenyldiyl group, methylenebisphenyl group, fluorenyl group, and the like.

  Examples of the heteroarylene group include a carbazole ring, a triazine ring, a triazole ring, a pyrrole ring, a pyridine ring, a pyrazine ring, a quinoxaline ring, a thiophene ring, an oxadiazole ring, a dibenzofuran ring, a dibenzothiophene ring, and an indole ring. Derived divalent groups and the like can be mentioned.

  Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a cyclopentyl group, and a cyclohexyl group. Etc.

  As the aryl group, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group Etc.

  Examples of the heteroaryl group include furyl group, thienyl group, pyridyl group, pyridazyl group, pyrimidyl group, pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzoimidazolyl group, benzoxazolyl group, quinazolyl group, Examples thereof include a phthalazyl group.

  n is preferably 10-30.

  In the present invention, the general formula (UP1) is preferably an embodiment represented by the following general formula (UP2).

In the general formula (UP2), R ₁ and R ₂ each independently represent an alkylene group, an arylene group, or a heteroarylene group. R ₇ is a methyl group, an ethyl group, or a propyl group. Incidentally, _{R 1} and _{R 2} have the same meanings as _{R 1} and _{R 2} in the general formula (UP1).

<Synthesis of polyurea>
Polyurea having a structure represented by the general formula (UP1) introduces a carbonyl group or a thiocarbonyl group into a disubstituted amine compound having R ₁ and R ₃ and a disubstituted amine compound having R ₂ and R ₄ a method of reacting a coupling agent, a disubstituted amine compounds with R ₁ and R _3, with the method, the R ₂ and R ₄ is reacted with isothiocyanate compound having an isocyanate compound or R ₂ having the R ₂ 2-substituted amine compounds can be synthesized by a method of reacting an isothiocyanate compound having an isocyanate compound or R ₁ having R _1.

  The starting materials are the amine compounds, isocyanate compounds, and isothiocyanate compounds substituted by the alkylene group, arylene group, heteroarylene group, alkyl group, aryl group, and heteroaryl group mentioned above.

In the case of synthesizing by a method in which a divalent amine compound having R ₁ and R ₃ and a disubstituted amine compound having R ₂ and R ₄ are reacted with a coupling agent for introducing a carbonyl group or a thiocarbonyl group, R _{1 is used.} Coupling of a compound having two disubstituted amino groups with R ₃ and R ₃ and a compound having two disubstituted amino groups with R ₂ and R ₄ , or disubstitution with R ₁ and R ₃ it may be a coupling of compounds having di-substituted amino group having an amino group and R ₂ and R ₄ one by one.

  Coupling agents that can be used are compounds capable of introducing a carbonyl group or a thiocarbonyl group, specifically phosgene, thiophosgene, 1,1'-carbonyldiimidazole, 1,1'-thiocarbonyldiimidazole, dimethyl carbonate. , Diphenyl carbonate, dimethylcarbonothioate, diphenylcarbonothioate, bis (trichloromethyl) carbonate, bis (trichloromethyl) carbonate, and the like.

  The amount of coupling agent used is preferably 1.1 to 1.5 equivalents per 1 equivalent of amine compound. More preferably, it is 1.1-1.2 equivalent.

  The reaction temperature for coupling depends on the coupling agent used, but is preferably as low as possible, -40 to 60 ° C, preferably -20 to 30 ° C, and more preferably -10 to 10 ° C. The reaction temperature may be a constant temperature from the start to the end of the reaction, or may be initially low and then increased.

On the other hand, the 2-substituted amine compounds with R ₁ and R _3, a method of reacting an isothiocyanate compound having an isocyanate compound or R ₂ having the R _2, the 2-substituted amine compounds with R ₂ and R _4, R _When reacting an isocyanate compound having ₁ or an isothiocyanate compound having R ₁ , the amine compound comprises a compound having two disubstituted amino groups having R ₁ and R ₃ , R ₂ and R ₄ A compound having two disubstituted amino groups, a compound having one disubstituted amino group having R ₁ and R ₃ and _one disubstituted amino group having R ₂ and R ₄ can be used. The isocyanate compound, diisothiocyanate compound having a diisocyanate compound or R ₂ having the R _2, diisocyanate compound having an R ₄ or diisothiocyanate compound having R ₄ can be used.

  The reaction temperature for polyaddition depends on the compound used, but is preferably as low as possible, -40 to 60 ° C, preferably -20 to 30 ° C, more preferably -10 to 10 ° C. The reaction temperature may be a constant temperature from the start to the end of the reaction, or may be initially low and then increased.

  As the solvent used for the reaction, it is necessary to use a highly polar solvent in order that the target resin composition is highly polar and the polymerization proceeds efficiently. For example, it is preferable to select a highly polar aprotic solvent such as DMF (N, N-dimethylformamide), DMAc (N, N-dimethylacetamide), DMSO (dimethylsulfoxide), NMP (N-methylpyrrolidone), As long as the reaction substrate and target compound dissolve well, aliphatic hydrocarbons such as cyclohexane, pentane and hexane, aromatic hydrocarbons such as benzene, toluene and chlorobenzene, THF (tetrahydrofuran), diethyl ether, ethylene glycol diethyl It may be a solvent such as ethers such as ether, ketones such as acetone, methyl ethyl ketone, 4-methyl-2-pentanone, esters such as methyl propionate, ethyl acetate, butyl acetate, etc. May be.

  The polyurea may be purified by any means, but purification by reprecipitation is preferred. The method of reprecipitation is not particularly limited, but a method in which polyurea is dissolved in a good solvent and then dropped into a poor solvent for precipitation is preferable.

  The “good solvent” as used herein may be any solvent as long as it dissolves the macromonomer, but is preferably a polar solvent, specifically, DMF (N, N-dimethylformamide), DMAc. Examples thereof include highly polar aprotic solvents such as (N, N-dimethylacetamide), DMSO (dimethyl sulfoxide), and NMP (N-methylpyrrolidone).

  The “poor solvent” may be any solvent as long as it does not dissolve the macromonomer, but is an aliphatic hydrocarbon such as cyclohexane, pentane or hexane, or an aromatic hydrocarbon such as benzene, toluene or chlorobenzene. And ethers such as diethyl ether and ethylene glycol diethyl ether, esters such as methyl propionate, ethyl acetate and butyl acetate, and alcohols such as methanol, ethanol and propanol.

  Specific examples of polyurea are given below, but the present invention is not limited thereto.

  The content of the polymer material in the organic piezoelectric material containing polyurea having the structure represented by the general formula (UP1) is 50 to 100% by mass ratio, and more preferably 70 to 100%.

  The use conditions are such that the polymer material that does not cause phase separation with the material to be mixed within the aforementioned mass ratio range is selected.

  An adjustment method for using an electromechanical coupling constant of 0.2 or more is that a film is produced from an organic piezoelectric material containing the polymer material, and the film is stretched, annealed, polarized, etc. It is obtained by applying. Annealing treatment and polarization treatment may be used in combination.

  In the case of a stretching process, it is desirable to stretch 2 to 5 times. Although the temperature at the time of stretching depends on the physical properties of the organic piezoelectric material, stretching at 20 to 150 ° C is preferable, and 40 to 120 ° C is more preferable. In the case of annealing treatment, it is necessary to carry out at a melting point or lower.

  In the case of the polarization treatment, various known methods such as direct current corona discharge treatment and alternating current application treatment can be used.

<Other organic polymer materials that can be used in combination>
In the present invention, various organic polymer materials can be used. Organic polymer materials formed from a polymerizable compound having an electron-withdrawing group having an action of increasing the amount of dipole moment of the organic polymer material. It is preferable that Since such an organic polymer material has an action of increasing the amount of dipole moment, excellent piezoelectric characteristics can be obtained when used as an organic piezoelectric material (film).

  In the present application, the “electron withdrawing group” refers to a substituent having a Hammett substituent constant (σp) of 0.10 or more as an index indicating the degree of electron withdrawing. As the value of Hammett's substituent constant σp here, Hansch, C .; It is preferable to use the values described in the report of Leo et al. (For example, J. Med. Chem. 16, 1207 (1973); ibid. 20, 304 (1977)).

  For example, the substituent or atom having a value of σp of 0.10 or more includes a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group, cyano group, nitro group, halogen-substituted alkyl group (for example, trichloro Methyl, trifluoromethyl, chloromethyl, trifluoromethylthiomethyl, trifluoromethanesulfonylmethyl, perfluorobutyl), aliphatic, aromatic or aromatic heterocyclic acyl groups (eg formyl, acetyl, benzoyl), aliphatic / aromatic Or aromatic heterocyclic sulfonyl group (for example, trifluoromethanesulfonyl, methanesulfonyl, benzenesulfonyl), carbamoyl group (for example, carbamoyl, methylcarbamoyl, phenylcarbamoyl, 2-chloro-phenylcarbamoyl), alkoxycarbonyl (For example, methoxycarbonyl, ethoxycarbonyl, diphenylmethylcarbonyl), substituted aryl groups (for example, pentachlorophenyl, pentafluorophenyl, 2,4-dimethanesulfonylphenyl, 2-trifluoromethylphenyl), aromatic heterocyclic groups (for example, 2 -Benzoxazolyl, 2-benzthiazolyl, 1-phenyl-2-benzimidazolyl, 1-tetrazolyl), azo group (eg phenylazo), ditrifluoromethylamino group, trifluoromethoxy group, alkylsulfonyloxy group (eg methanesulfonyl) Oxy), acyloxy groups (eg acetyloxy, benzoyloxy), arylsulfonyloxy groups (eg benzenesulfonyloxy), phosphoryl groups (eg dimethoxyphosphonyl, diphenylphosphoryl) ), Sulfamoyl groups (for example, N-ethylsulfamoyl, N, N-dipropylsulfamoyl, N- (2-dodecyloxyethyl) sulfamoyl, N-ethyl-N-dodecylsulfamoyl, N, N-diethyl) Sulfamoyl) and the like.

  Specific examples of the compound that can be used in the present invention include the following compounds or derivatives thereof, but are not limited thereto.

  4,4'-diaminodiphenylmethane (MDA), 4,4'-methylenebis (2-methylaniline), 4,4'-methylenebis (2,6-dimethylaniline), 4,4'-methylenebis (2-ethyl- 6-methylaniline), 4,4'-methylenebis (2,6-diethylaniline), 4,4'-methylenebis (2,6-di-t-butylaniline), 4,4'-methylenebis (2,6 -Dicyclohexylaniline), 4,4'-methylenebis (2-ethylaniline), 4,4'-methylenebis (2-tert-butylaniline), 4,4'-methylenebis (2-cyclohexylaniline), 4,4 ' -Methylenebis (3,5-dimethylaniline), 4,4'-methylenebis (2,3-dimethylaniline), 4,4'-methylenebis (2,5-dimethyl) Nilin), 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) propane, 1,1-bis (4-aminophenyl) cyclohexane, α, α-bis ( 4-aminophenyl) toluene, 4,4'-methylenebis (2-chloroaniline), 4,4'-methylenebis (2,6-dichloroaniline), 4,4'-methylenebis (2,3-dibromoaniline), 3,4'-diaminodiphenyl ether, 4,4'-diaminooctafluorodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl disulfide, bis (4-aminophenyl) sulfone, bis (3-amino Phenyl) sulfone, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino) Phenyl) sulfoxide, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis [4 -(4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,5-bis (4-aminophenyl) -1,3,4-oxa Diazole, neopentyl glycol bis (4-aminophenyl) ether, 4,4'-diaminostilbene, α, α'-bis (4-aminophenyl) -1,4-diisopropylbenzene, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, benzidine, 4,4'-diaminooctafluorobiphenyl, 3 3'-diaminobenzidine, 3,3'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine, 3,3 ', 5,5'-tetramethylbenzidine, 3,3'-dihydroxybenzidine, 3 , 3'-dimethylbenzidine, 3,3'-dihydroxy-5,5'-dimethylbenzidine, 4,4 "-diamino-p-terphenyl, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2, 3-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 3,3′-dimethylnaphthidine, 2,7-diaminocarbazole, 3,6-diaminocarbazole, 3,4-diaminobenzoic acid, 3,5-diaminobenzoic acid, 1,5-diaminopentane, 1.6-diaminohexane, 1,7-diminoheptane, 1 8-diaminooctane, 1,9-diaminononane, 1,5-dimethylhexylamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-1: 4, 4'- Diaminobenzophenone, 4,4'-dimethylamino-3,3'-dichlorobenzophenone, 4,4'-diamino-5,5'-diethyl-3,3'-difluorobenzophenone, 4,4'-diamino-3, 3 ', 5,5'-tetrafluorobenzophenone, 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-amino-3,5-dichlorophenyl) propane, 2,2-bis (4 -Aminophenyl) hexafluoropropane, 2,2-bis (4-amino-3-fluorophenyl) hexafluoropropane, 4,4'-diamy Nodiphenyl ether (ODA), 4,4'-diamino-3,3 ', 5,5'-tetrachlorodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diamino-3,3'-dibromodiphenyl Sulfide, 4,4'-diaminodiphenyl disulfide, 4,4'-diamino-3,3 ', 5,5'-tetrafluorodiphenyl disulfide, bis (4-aminophenyl) sulfone, bis (4-amino-3- Chloro-5-methylphenyl) sulfone, bis (4-aminophenyl) sulfoxide, bis (4-amino-3-bromophenyl) sulfoxide, 1,1-bis (4-aminophenyl) cyclopropane, 1,1-bis (4-aminophenyl) cyclooctane, 1,1-bis (4-aminophenyl) cyclohexane, 1, -Bis (4-amino-3,5-difluorophenyl) cyclohexane, 4,4 '-(cyclohexylmethylene) dianiline, 4,4'-(cyclohexylmethylene) bis (2,6-dichloroaniline), 2,2- Diethyl bis (4-aminophenyl) malonate, diethyl 2,2-bis (4-amino-3-chlorophenyl) malonate, 4- (di-p-aminophenylmethyl) pyridine, 1- (di-p-aminophenylmethyl) ) Diamine compounds such as -1H-pyrrole, 1- (di-p-aminophenylmethyl) -1H-imidazole, 2- (di-p-aminophenylmethyl) oxazole and their derivatives, and 4,4'-diphenylmethane diisocyanate (MDI), 4,4'-methylenebis (2,6-dimethylphenyl isocyanate), 4,4'-me Renbis (2,6-diethylphenyl isocyanate), 4,4'-methylenebis (2,6-di-t-butylphenyl isocyanate), 4,4'-methylenebis (2,6-dicyclohexylphenyl isocyanate), 4,4'-methylenebis (2-methylphenylisocyanate), 4,4'-methylenebis (2-ethylphenylisocyanate), 4,4'-methylenebis (2-t-butylphenylisocyanate), 4,4 '-Methylenebis (2-cyclohexylphenyl isocyanate), 4,4'-methylenebis (3,5-dimethylphenylisocyanate), 4,4'-methylenebis (2,3-dimethylphenylisocyanate), 4,4' -Methylenebis (2,5-dimethylphenyl isocyanate), 2,2-bis (4- Isocyanatophenyl) hexafluoropropane, 2,2-bis (4-isocyanatophenyl) propane, 1,1-bis (4-isocyanatophenyl) cyclohexane, α, α-bis (4-isocyanatophenyl) toluene, 4,4'-methylenebis (2,6-dichlorophenylisocyanate), 4,4'-methylenebis (2-chlorophenylisocyanate), 4,4'-methylenebis (2,3-dibromophenylisocyanate), m-xyl Range isocyanate, 4,4'-diisocyanate-3,3'-dimethylbiphenyl, 1,5-diisocyanatonaphthalene, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2, 4-toluene diisocyanate (2,4-TDI), 2,6-toluene di Isocyanate (2,6-TDI), 1,3-bis (2-isocyanato-2-propyl) benzene, 1,3-bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane-4,4'-diisocyanate , Isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, 2,7-full orange isocyanate, benzophenone-4,4'-diisocyanic acid, 3,3'-dichlorobenzophenone-4,4'-diisocyanate Acid, 5,5'-diethyl-3,3'-difluorobenzophenone-4,4'-diisocyanic acid, 2,2-bis (4-isocyanatophenyl) propane, 2,2-bis (3,5-dichloro- 4-isocyanatophenyl) propane, 2,2-bis (4-isocyanate) Phenphenyl) hexafluoropropane, 2,2-bis (3-fluoro-4-isocyanatophenyl) hexafluoropropane, bis (4-isocyanatephenyl) ether, bis (3,5-difluoro-4-isocyanatophenyl) ether, bis (4-isocyanate phenyl) sulfide, bis (3,5-dibromo-4-isocyanate phenyl) sulfide, bis (4-isocyanate phenyl) disulfide, bis (4-isocyanate phenyl) sulfone, bis (4-isocyanate phenyl) sulfoxide, Bis (3,5-difluoro-4-isocyanatophenyl) sulfoxide, 1,1-bis (4-isocyanatophenyl) cyclopropane, 1,1-bis (4-isocyanatophenyl) cyclooctane, 1, -Bis (4-isocyanatophenyl) cyclohexane, 1,1-bis (3,5-dichloro-4-isocyanatophenyl) cyclohexane, 4,4 '-(cyclohexylmethylene) bis (isocyanatebenzene), 4,4'-( Cyclohexylmethylene) bis (1-isocyanate-2-chlorobenzene), diethyl 2,2-bis (4-isocyanatephenyl) malonate, diethyl 2,2-bis (3-chloro-4-isocyanatophenyl) malonate, 4- (Di-p-isocyanatophenylmethyl) pyridine, 1- (di-p-isocyanatophenylmethyl) -1H-pyrrole, 1- (di-p-isocyanatophenylmethyl) -1H-imidazole, 2- (di-p-isocyanatephenylmethyl) Diisocyanate compounds such as oxazole And derivatives thereof, 4,4'-diphenylmethane diisothiocyanate, 4,4'-methylenebis (2,6-diethylphenylisothiocyanate), 4,4'-methylenebis (2,6-di-t- Butylphenyl isothiocyanate), 1,3-bis (isothiocyanatomethyl) cyclohexane, benzophenone-4,4'-diisothiocyanic acid, 3,3'-difluorobenzophenone-4,4'-diisothiocyanic acid, 2, 2-bis (3,5-dichloro-4-isothiocyanatephenyl) propane, bis (4-isothiocyanatephenyl) ether, bis (4-isothiocyanatephenyl) sulfone, bis (4-isothiocyanatephenyl) sulfoxide, bis ( 3,5-difluoro-4-isothiocyanatophenyl) sulfur Xoxide, 1,1-bis (4-isothiocyanatophenyl) cyclopropane, 1,1-bis (4-isothiocyanatophenyl) cyclooctane, 4,4 '-(cyclohexylmethylene) bis (isothiocyanate benzene), 2, Diisothiocyanate compounds such as diethyl 2-bis (4-isothiocyanatephenyl) malonate, 1- (di-p-isothiocyanatophenylmethyl) -1H-pyrrole, 2- (di-p-isothiocyanatephenylmethyl) oxazole and the like Is a derivative.

  Hereinafter, the organic polymer material that can be used in the present invention will be described in more detail.

  In the present invention, the organic polymer material constituting the organic piezoelectric material preferably contains a compound having a urea bond or a thiourea bond as a constituent component, and the compound is represented by the following general formulas (1) to (3). It is also preferable that the compound represented by the formula or derivatives of these compounds be used as a raw material.

(Wherein R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group, a 3- to 10-membered non-aromatic cyclic group, an aryl group, or a heteroaryl group, and these groups further have a substituent. R _{21 to} R ₂₆ each independently represents a hydrogen atom, an alkyl group, or an electron-withdrawing group.)

(In the formula, each R ₁₃ independently represents a carboxyl group, a hydroxy group, a mercapto group, or an amino group, and these active hydrogens are further an alkyl group, a 3- to 10-membered non-aromatic ring group, an aryl group, or It may be substituted with a heteroaryl group or the like, and R ₁₃ represents a carbonyl group, a sulfonyl group, a thiocarbonyl group, or a sulfone group, and these substituents bind a hydrogen atom, an aryl group, or a heteroaryl group R _{21 to} R ₂₆ represent a group having the same meaning as R _{21 to} R _{26 in} the general formula (1).

(Wherein, Y each independently represents a keto group, an oxime group, a substituted vinylidene _group, R 21 _{to R 26} represents _R 21 _{to R 26} as defined substituents in formula (1).)
Preferable examples include compounds represented by the general formulas (1) to (3) or derivatives of these compounds.

<< Compound Represented by Formula (1) >>
Examples of the compound represented by the general formula (1) include 2,7-diaminofluorene, 2,7-diamino-4,5-dinitrofluorene, 2,7-diamino-3,4,5, 6-tetrachlorofluorene. 2,7-diamino-3,6-difluorofluorene, 2,7-diamino-9- (n-hexyl) fluorene, 9,9-dimethyl-2,7-diaminofluorene, 2,7-diamino-9- Benzylfluorene, 9,9-bisphenyl-2,7-diaminofluorene, 2,7-diamino-9-methylfluorene, 9,9-bis (3,4-dichlorophenyl) -2,7-diaminofluorene, 9, 9-bis (3-methyl-4-chlorophenyl) -2,7-diaminofluorene, 9,9-bis (methyloxyethyl) -2,7-diaminofluorene, 2,7-di Mino-3,6-dimethyl-9-aminomethyl fluorene, and the like although not limited thereto.

<< Compound Represented by Formula (2) >>
Examples of the compound represented by the general formula (2) include 2,7-diamino-9-fluorenecarboxylic acid, 2,7-diamino-9-fluorenecarboxaldehyde, 2,7-diamino-9-hydroxyfluorene, 2, 7-diamino-3,6-difluoro-9-hydroxyfluorene, 2,7-diamino-4,5-dibromo-9-mercaptofluorene, 2,7,9-triaminofluorene, 2,7-diamino-9- Hydroxymethylfluorene, 2,7-diamino-9- (methyloxy) fluorene, 2,7-diamino-9-acetoxyfluorene, 2,7-diamino-3,6-diethyl-9- (perfluorophenyloxy) fluorene 2,7-diamino-4,5-difluoro-9- (acetamido) fluorene, 2,7-diamino-N-isopropyl Rufuruoren 9-carboxamide, 2,7-diamino-4,5-dibromo-9-methylsulfinyl fluorene, but like not limited.

<< Compound Represented by Formula (3) >>
As the compound represented by the general formula (3), 9,9-dimethyl-2,7-diaminofluorenone, 2,7-diamino-9-benzylfluorenone, 9,9-bisphenyl-2,7-diaminofluorenone 2,7-diamino-9-methylfluorenone, 9,9-bis (3,4-dichlorophenyl) -2,7-diaminofluorenone, 9,9-bis (3-methyl-4-chlorophenyl) -2,7 -Diaminofluorenone, 9-hexylidene-2,7-diamino-4,5-dichlorofluorene, 1- (2,7-diamino-9-fluorenylidene) -2-phenylhydrazine, 2-((2,7-diamino- 1,8-dimethyl-9-fluorenylidene) methyl) pyridine, and the like.

  In the present invention, for example, the above fluorene exemplified compound is reacted with an aliphatic or aromatic diol, diamine, diisocyanate, diisothiocyanate or the like to form a polyurea or polyurethane structure, and then the following general formulas (4) to ( It can also be mixed with the compound represented by 6) or a high molecular weight product formed from them to form a composite material.

(In the formula, each Ra independently represents a hydrogen atom, an alkyl group, an aryl group, an alkyl group containing an electron-withdrawing group, an aryl group or a heteroaryl group containing an electron-withdrawing group. X is a carbon that can be bonded. Or n may be absent, and n represents an integer of X valence of −1 or less.)
Examples of the compound represented by the compound represented by the general formula (4) include p-acetoxystyrene, p-acetylstyrene, p-benzoylstyrene, p-trifluoroacetylstyrene, p-monochloroacetylstyrene, p- (par Fluorobutyryloxy) styrene, p- (perfluorobenzoyloxy) styrene, S-4-vinylphenylpyridine-2-carbothioate, and N- (4-vinylphenyl) picolinamide, etc. Absent.

(In the formula, each Rb independently represents an alkyl group containing an electron-withdrawing group, an aryl group or a heteroaryl group containing an electron-withdrawing group. X may or may not be an atom other than carbon that can be bonded. n is the valence of X-1 or less.)
Examples of the compound represented by the general formula (5) include p-trifluoromethylstyrene, p-dibromomethylstyrene, p-trifluoromethoxystyrene, p-perfluorophenoxystyrene, and p-bis (trifluoromethyl) aminostyrene. , And p- (1H-imidazolyloxy) styrene, but are not limited thereto.

(In the formula, each Rc independently represents an alkyl group containing an electron-withdrawing group, an aryl group or a heteroaryl group containing an electron-withdrawing group. X may or may not be an atom other than carbon that can be bonded. n represents an integer of X valence of −1 or less.)
Examples of the compound represented by the general formula (6) include p- (methanesulfonyloxy) styrene, p- (trifluoromethanesulfonyloxy) styrene, p-toluenesulfonylstyrene, p- (perfluoropropylsulfonyloxy) styrene, p. Examples include-(perfluorobenzenesulfonyloxy) styrene, (4-vinylphenyl) bis (trifluoromethanesulfonyl) amide, and the like.

  In the present invention, alcohol compounds such as ethylene glycol, glycerin, triethylene glycol, polyethylene glycol, polyvinyl alcohol, and 4,4-methylenebisphenol, ethanolamine having both an amino group and a hydroxyl group, aminobutylphenol, 4- Amino alcohols such as (4-aminobenzyl) phenol (ABP), aminophenols, and the like can also be used.

(Organic piezoelectric film)
The organic piezoelectric film according to the present invention can be produced using the above piezoelectric material by various conventionally known methods such as a melting method and a casting method.

  In the present invention, as a method for producing an organic piezoelectric film, basically, a method of applying a solution of the above polymer material or the like on a substrate and drying it, or using a raw material compound of the above polymer material has been conventionally used. A method of forming a polymer film by a known solution polymerization coating method or the like can be employed.

  Specific methods and conditions of the solution polymerization coating method can be carried out according to various conventionally known methods. For example, a method of forming an organic piezoelectric film by applying a mixed solution of raw materials on a substrate, drying to some extent under reduced pressure conditions (after removing the solvent), heating, thermal polymerization, and then or simultaneously performing polarization treatment Is preferred.

  In order to improve the piezoelectric characteristics, it is useful to add a process for aligning the molecular arrangement. Examples of means include stretching film formation and polarization treatment.

  Various known methods can be adopted for the method of stretching film formation. For example, a solution in which the above organic polymer material is dissolved in an organic solvent such as ethyl methyl ketone (MEK) is cast on a substrate such as a glass plate, and the solvent is dried at room temperature to obtain a film having a desired thickness. Then, the film is stretched to a predetermined length at room temperature. The stretching can be performed in a uniaxial / biaxial direction so that the organic piezoelectric film having a predetermined shape is not destroyed. The draw ratio is 2 to 10 times, preferably 2 to 6 times.

(Polarization treatment)
As a polarization treatment method in the polarization treatment according to the present invention, a conventionally known method such as DC voltage application treatment, AC voltage application treatment, or corona discharge treatment can be applied.

  For example, in the case of the corona discharge treatment method, the corona discharge treatment can be performed by using a commercially available device comprising a high voltage power source and electrodes.

  Since the discharge conditions vary depending on the equipment and the processing environment, it is preferable to select the conditions as appropriate. The voltage of the high voltage power source is preferably -1 to -20 kV, the current is 1 to 80 mA, the distance between the electrodes is preferably 1 to 10 cm, and the applied voltage is preferably 0.5 to 2.0 MV / m. .

  As the electrodes, needle-like electrodes, linear electrodes (wire electrodes), and mesh-like electrodes that have been conventionally used are preferable, but the invention is not limited thereto.

  In the case where the organic piezoelectric material of the present invention is subjected to polarization treatment by corona discharge, a planar electrode is disposed so as to be in contact with the first surface of the organic piezoelectric material, and the second electrode is opposed to the first surface. It is preferable that a columnar corona discharge electrode is installed on the surface side of the electrode and the polarization treatment is performed by corona discharge.

  The polarization treatment prevents the oxidation of the surface of the material due to water and oxygen and does not impair the piezoelectricity. For this reason, the absolute mass humidity is 0.004 or less in a nitrogen or rare gas (helium, argon, etc.) stream. The embodiment applied in the environment is preferred. A nitrogen stream is particularly preferable.

  In addition, at least one of an organic piezoelectric material including a planar electrode placed in contact with the first surface or a cylindrical corona discharge electrode provided on the second surface side moves at a constant speed. However, corona discharge is preferably performed.

In the present application, “mass absolute humidity” means that when the mass of water vapor contained in the humid air is m _w [kg] with respect to the mass m _DA [kg] of dry air, The ratio SH (Specific humidity) defined by is expressed in [kg / kg (DA)] (DA is an abbreviation of dry air). However, in the present application, the unit is omitted.

(Formula): SH = m _w / m _DA [kg / kg (DA)]
Here, air containing water vapor is referred to as “wet air”, and air obtained by removing water vapor from the humid air is referred to as “dry air”.

In addition, the definition of mass absolute humidity under nitrogen or rare gas (helium, argon, etc.) airflow is the same as the case of the above-mentioned air, and the moisture vapor contained in the wet gas with respect to the dry gas mass m _DG [kg]. When the mass is m _w [kg], it means the ratio SH defined according to the above formula, and the unit is represented by [kg / kg (DG)] (DG is an abbreviation for dry gas). However, in the present application, the unit is omitted.

  In addition, “installation” means that an existing electrode separately prepared in advance is placed so as to be in contact with the surface of the organic piezoelectric material, or the electrode constituent material is attached to the surface of the organic piezoelectric material by a vapor deposition method or the like. It refers to forming an electrode above.

  In addition, it is preferable that the organic piezoelectric film formed of the organic piezoelectric material of the present invention is formed in an electric field in the formation process, that is, a polarization treatment is performed in the formation process. At this time, a magnetic field may be used in combination.

  In the corona discharge treatment method according to the present invention, the treatment can be performed using a commercially available apparatus comprising a high voltage power source and electrodes.

  Since the discharge conditions vary depending on the equipment and processing environment, it is preferable to select the conditions as appropriate. However, the voltage of the high voltage power supply is 1 to 20 kV for both positive and negative voltages, 1 to 80 mA for the current, and the distance between the electrodes. 0.5-10 cm is preferable, and the applied electric field is preferably 0.5-2.0 MV / m. The organic piezoelectric material or the organic piezoelectric film during the polarization treatment is preferably 50 to 250 ° C, more preferably 70 to 180 ° C.

  As an electrode used for corona discharge, it is necessary to use a columnar electrode as described above in order to perform a polarization treatment uniformly.

  In addition, in this application, it is preferable that the diameter of the circle | round | yen of a cylindrical electrode is 0.1 mm-2 cm. The length of the cylinder is preferably set to an appropriate length according to the size of the organic piezoelectric material to be polarized. For example, in general, the thickness is preferably 5 cm or less from the viewpoint of uniformly performing the polarization treatment.

  These electrodes are preferably stretched at a portion where corona discharge is performed, and can be realized by a method of applying a constant weight to both ends of the electrodes or fixing the electrodes in a state where a constant weight is applied. Moreover, as a constituent material of these electrodes, a general metal material can be used, but gold, silver and copper are particularly preferable.

  In order to perform a uniform polarization process, it is preferable that the planar electrode placed so as to be in contact with the first surface is in close contact with the organic piezoelectric material. That is, it is preferable to perform corona discharge after forming an organic polymer film or an organic piezoelectric film on a substrate provided with a planar electrode.

  In addition, as a manufacturing method of the ultrasonic transducer | vibrator which concerns on this invention, before the formation of the electrode installed in both surfaces of an organic piezoelectric (body) film | membrane, a polarization process is carried out either after an electrode formation on one side or after an electrode formation on both sides It is preferable that it is the manufacturing method of the aspect to do. Moreover, it is preferable that the said polarization process is a voltage application process.

  In this invention, the method of removing the solvent in a solution can be taken, applying a magnetic field to the apply | coated coating film. Here, “removing the solvent while applying a magnetic field” means having a step of applying a magnetic field between the steps of removing the solvent. The removal of the solvent in the step of removing the solvent may be continuous or intermittent. When the removal of the solvent is intermittent, the step of applying a magnetic field may be performed while the solvent is removed, or may be performed while the solvent is not removed.

  Although depending on the solvent used and the drying temperature, it is preferable to apply a magnetic field approximately 1 minute after application. This is because in the case immediately after coating, the flow alignment by diffusion of the coating solution is superior to the magnetic field alignment, and when it is further delayed, the drying proceeds and the alignment is hindered by the increase in viscosity.

  The time for applying the magnetic field is preferably the time until the coating film is completely dried.

  The magnetic flux density of the magnetic field is preferably 1 to 30T, and particularly preferably 5 to 20T, from the viewpoint of the uniformity of the coating film.

  In the present invention, by applying a magnetic field, the orientation of the aromatic ring can be increased and the orientation of the functional group bonded to the aromatic ring can be controlled. Therefore, the direction of the magnetic field depends on the structure of the macromonomer, and there are two cases where it is preferable to write perpendicularly to the coating film and to write horizontally.

  In the present invention, it is preferable that the organic piezoelectric material is subjected to polarization treatment by an electric field or a combination of an electric field and a magnetic field as described above.

(substrate)
As the substrate, the selection of the substrate varies depending on the use and usage of the organic piezoelectric film according to the present invention. In the present invention, a plastic plate or film such as polyimide, polyamide, polyimide amide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethyl methacrylate (PMMA), polycarbonate resin, or cycloolefin polymer is used. Can do. Further, the surface of these materials may be covered with aluminum, gold, copper, magnesium, silicon or the like. A single crystal plate or film of aluminum, gold, copper, magnesium, silicon alone, or a rare earth halide may also be used. The substrate itself may not be used.

(Ultrasonic transducer)
The ultrasonic transducer according to the present invention is characterized by using an organic piezoelectric film formed using the organic piezoelectric material of the present invention. The ultrasonic transducer is preferably an ultrasonic receiving transducer used in an ultrasonic medical diagnostic imaging device probe including an ultrasonic transmitting transducer and an ultrasonic transmitting transducer. .

  In general, an ultrasonic vibrator has a pair of electrodes sandwiched between layers (or films) made of a film-like piezoelectric material (also referred to as “piezoelectric film”, “piezoelectric film”, or “piezoelectric layer”). An ultrasonic probe is configured by arranging a plurality of transducers, for example, one-dimensionally.

  Then, a predetermined number of transducers in the major axis direction in which a plurality of transducers are arranged is set as the aperture, and the plurality of transducers belonging to the aperture are driven to focus the ultrasonic beam on the measurement site in the subject. And has a function of receiving reflected echoes of ultrasonic waves emitted from the subject by a plurality of transducers belonging to the aperture and converting them into electrical signals.

  Hereinafter, each of the ultrasonic wave receiving transducer and the ultrasonic wave transmitting transducer according to the present invention will be described in detail.

<Ultrasound receiving transducer>
An ultrasonic receiving vibrator according to the present invention is a vibrator having an ultrasonic receiving piezoelectric material used for a probe for an ultrasonic medical diagnostic imaging apparatus, and the piezoelectric material constituting the ultrasonic receiving vibrator is an element of the present invention. An embodiment using an organic piezoelectric film formed using an organic piezoelectric material is preferable.

The organic piezoelectric material or the organic piezoelectric film used for the ultrasonic receiving vibrator preferably has a relative dielectric constant of 10 to 50 at the thickness resonance frequency. The relative dielectric constant is adjusted by adjusting the number, composition, degree of polymerization, etc. of the polar functional groups such as the substituent R, CF ₂ group, and CN group of the compound constituting the organic piezoelectric material, and the polarization treatment described above. Can be done by.

  The organic piezoelectric film constituting the receiving vibrator of the present invention can also be configured by laminating a plurality of polymer materials. In this case, as the polymer material to be laminated, the following polymer material having a relatively low relative dielectric constant can be used in addition to the above polymer material.

  In the following examples, the numerical values in parentheses indicate the relative dielectric constant of the polymer material (resin).

  For example, methyl methacrylate resin (3.0), acrylonitrile resin (4.0), acetate resin (3.4), aniline resin (3.5), aniline formaldehyde resin (4.0), aminoalkyl resin ( 4.0), alkyd resin (5.0), nylon-6-6 (3.4), ethylene resin (2.2), epoxy resin (2.5), vinyl chloride resin (3.3), chloride Vinylidene resin (3.0), urea formaldehyde resin (7.0), polyacetal resin (3.6), polyurethane (5.0), polyester resin (2.8), polyethylene (low pressure) (2.3), Polyethylene terephthalate (2.9), polycarbonate resin (2.9), melamine resin (5.1), melamine formaldehyde resin (8.0), cellulose acetate (3.2), acetic acid Sulfonyl resin (2.7), styrene resins (2.3), styrene butadiene rubber (3.0), styrene resin (2.4), it can be used polytetrafluoroethylene (2.0) or the like.

  The polymer material having a low relative dielectric constant is preferably selected in accordance with various purposes such as adjusting the piezoelectric characteristics or imparting the physical strength of the organic piezoelectric film. .

<Transmitter for ultrasonic transmission>
The ultrasonic transmission vibrator according to the present invention is preferably made of a piezoelectric material having an appropriate relative dielectric constant in relation to the vibrator having the receiving piezoelectric material. Moreover, it is preferable to use a piezoelectric material excellent in heat resistance and voltage resistance.

  Various known organic piezoelectric materials and inorganic piezoelectric materials can be used as the ultrasonic transmitting vibrator constituent material.

  As the organic piezoelectric material, a polymer material similar to the above-described organic piezoelectric material for constituting an ultrasonic receiving vibrator can be used.

Inorganic materials include quartz, lithium niobate (LiNbO ₃ ), potassium tantalate niobate [K (Ta, Nb) O ₃ ], barium titanate (BaTiO ₃ ), lithium tantalate (LiTaO ₃ ), or titanate Lead zirconate (PZT), strontium titanate (SrTiO ₃ ), barium strontium titanate (BST), or the like can be used. PZT is preferably Pb (Zr _1-n Ti _n ) O ₃ (0.47 ≦ n ≦ 1).

<electrode>
The piezoelectric (body) vibrator according to the present invention is manufactured by forming electrodes on both surfaces or one surface of a piezoelectric film (layer) and polarizing the piezoelectric film. When producing an ultrasonic wave receiving vibrator using an organic piezoelectric material, the electrode on the first surface used for the polarization treatment may be used as it is. The electrode is formed using an electrode material mainly composed of gold (Au), platinum (Pt), silver (Ag), palladium (Pd), copper (Cu), nickel (Ni), tin (Sn), or the like. .

  In forming the electrodes, first, a base metal such as titanium (Ti) or chromium (Cr) is formed to a thickness of 0.02 to 1.0 μm by sputtering, and then the metal mainly composed of the above metal elements and those A metal material made of the above alloy, and further, if necessary, a part of the insulating material is formed to a thickness of 1 to 10 μm by sputtering, vapor deposition or other suitable methods. In addition to sputtering, these electrodes can be formed by screen printing, dipping, or thermal spraying using a conductive paste in which fine metal powder and low-melting glass are mixed.

  Furthermore, a piezoelectric element is obtained by supplying a predetermined voltage between the electrodes formed on both surfaces of the piezoelectric film to polarize the piezoelectric film.

(Ultrasonic probe)
The ultrasonic probe according to the present invention is a main component of an ultrasonic diagnostic imaging apparatus and has a function of generating ultrasonic waves and transmitting / receiving ultrasonic beams. The internal configuration of the ultrasonic probe may take various forms, but as a general configuration, from the tip (surface contacting the living body that is the subject), the “acoustic lens”, “acoustic matching layer”, A configuration of an aspect in which “ultrasonic transducer (element)” and “backing” are juxtaposed in this order may be employed.

  An ultrasonic probe according to the present invention is a probe for an ultrasonic medical image diagnostic apparatus including an ultrasonic transmission transducer and an ultrasonic reception transducer. The ultrasonic receiving transducer according to the invention is used.

  In the present invention, both transmission and reception of ultrasonic waves may be performed by a single transducer, but more preferably, the transducers are configured separately for transmission and reception in the probe.

  The piezoelectric material constituting the transmitting vibrator may be a conventionally known ceramic inorganic piezoelectric material or an organic piezoelectric material.

  In the ultrasonic probe according to the present invention, the ultrasonic receiving transducer of the present invention can be arranged on or in parallel with the transmitting transducer.

  As a more preferred embodiment, the structure for laminating the ultrasonic receiving transducer of the present invention on the ultrasonic transmitting transducer is good, and in this case, the ultrasonic receiving transducer of the present invention is another high-frequency transducer. You may laminate | stack on the vibrator | oscillator for transmission in the form joined together on the molecular material (The polymer (resin) film, for example, polyester film) whose relative dielectric constant is comparatively low as a support body. In this case, it is preferable that the film thickness of the receiving vibrator and the other polymer material be matched to a preferable receiving frequency band in terms of probe design. Considering a practical ultrasonic medical diagnostic imaging apparatus and biological information collection from a practical frequency band, the film thickness is preferably 40 to 150 μm.

  The probe may be provided with a backing layer, an acoustic matching layer, an acoustic lens, and the like. Also, a probe in which vibrators having a large number of piezoelectric materials are two-dimensionally arranged can be used. A plurality of two-dimensionally arranged probes can be sequentially scanned to form a scanner.

(Acoustic lens)
The acoustic lens according to the present invention is arranged to focus an ultrasonic beam using refraction and improve resolution. The present invention is characterized in that a substance that emits light when irradiated with excitation light, that is, a luminescent substance is added to a region near the subject surface of the acoustic lens.

The acoustic lens converges the ultrasonic wave and is in close contact with the living body to match the acoustic impedance of the living body (density × sound speed; (1.4 to 1.6) × 10 ⁶ kg / m ² · sec), It is a necessary condition that the reflection of ultrasonic waves can be reduced and that the ultrasonic attenuation amount of the lens itself is small.

  That is, an acoustic lens conventionally made of a polymer material such as rubber is provided at a portion that comes into contact with the human body to focus the ultrasonic beam. As the lens material used here, it is desirable that the sound velocity is sufficiently smaller than that of the human body, the attenuation is small, and the acoustic impedance is close to the value of the human skin. If the lens material has a sound velocity sufficiently smaller than that of the human body, the lens shape can be made convex, and slipping can be performed safely when making a diagnosis, and if the attenuation is reduced, sensitivity is improved. If the ultrasonic impedance can be transmitted and received and the acoustic impedance is close to the value of the skin of the human body, the reflection will be small, in other words, the transmittance will be large. Because.

  In the present invention, the material constituting the acoustic lens includes conventionally known homopolymers such as silicon rubber, fluorine silicon rubber, polyurethane rubber, epichlorohydrin rubber, and ethylene-propylene copolymer rubber obtained by copolymerizing ethylene and propylene. Copolymer rubber etc. can be used. Of these, it is preferable to use silicon rubber.

  Examples of the silicon rubber used in the present invention include silicon rubber and fluorine silicon rubber. In particular, it is preferable to use silicon rubber because of the characteristics of the lens material. Silicon rubber is an organopolysiloxane having a molecular skeleton composed of Si—O bonds, and having a plurality of organic groups bonded to Si atoms. Usually, the main component is methylpolysiloxane, and the entire organic structure is organic. 90% or more of the groups are methyl groups. A material in which a hydrogen atom, a phenyl group, a vinyl group, an allyl group or the like is introduced instead of the methyl group can also be used. The silicone rubber can be obtained, for example, by kneading a curing agent (vulcanizing agent) such as benzoyl peroxide in an organopolysiloxane having a high polymerization degree, followed by heat vulcanization and curing. If necessary, organic or inorganic fillers such as silica and nylon powder, and vulcanization aids such as sulfur and zinc oxide may be added.

  Examples of the butadiene rubber used in the present invention include butadiene alone or a copolymer rubber mainly composed of butadiene and copolymerized with a small amount of styrene or acrylonitrile. In particular, it is preferable to use butadiene rubber because of the characteristics of the lens material. The butadiene rubber refers to a synthetic rubber obtained by polymerization of butadiene having a conjugated double bond. Butadiene rubber can be obtained by 1,4 or 1.2 polymerization of butadiene alone having a conjugated double bond. A butadiene rubber vulcanized with sulfur or the like can be used.

  The acoustic lens according to the present invention can be obtained by mixing silicon rubber and butadiene rubber and curing them. For example, it can be obtained by mixing silicon rubber and butadiene rubber with a kneading roll at an appropriate ratio, adding a vulcanizing agent such as benzoyl peroxide, and heat vulcanizing and crosslinking (curing). At that time, it is preferable to add zinc oxide as a vulcanization aid. Zinc oxide can accelerate vulcanization and shorten the vulcanization time without deteriorating lens characteristics. In addition, other additives may be added as long as the characteristics of the colorant and the acoustic lens are not impaired. The mixing ratio of the silicone rubber and the butadiene rubber is preferably 1: 1 in order to obtain a material whose acoustic impedance is close to that of the human body and whose sound speed is smaller than that of the human body and less attenuated. The mixing ratio can be changed as appropriate.

  In the present invention, an inorganic filler such as silica, alumina, titanium oxide, nylon, etc., depending on the purpose of adjusting the speed of sound, adjusting the density, etc., based on the rubber material such as silicon rubber (main component). An organic resin or the like can also be blended.

(Backing layer)
In the present invention, it is also preferable that a backing layer is provided on the back surface of the ultrasonic transducer for the purpose of suppressing propagation of ultrasonic waves to the rear. Thereby, the pulse width can be shortened.

(Acoustic matching layer)
The acoustic matching layer (also referred to as “λ / 4 layer”) is arranged in multiple layers in order to reduce the difference in acoustic impedance between the transducer and the living body and efficiently transmit and receive ultrasonic waves.

(Ultrasonic medical diagnostic imaging equipment)
The ultrasonic probe according to the present invention can be used for various types of ultrasonic diagnostic apparatuses. FIG. 1 is a conceptual diagram showing the configuration of the main part of an ultrasonic medical image diagnostic apparatus according to an embodiment of the present invention.

  This ultrasonic medical diagnostic imaging apparatus transmits an ultrasonic wave to a subject such as a patient, and an ultrasonic probe in which piezoelectric vibrators that receive ultrasonic waves reflected by the subject as echo signals are arranged. (Probe). In addition, an electric signal is supplied to the ultrasonic probe to generate an ultrasonic wave, and a transmission / reception circuit that receives an echo signal received by each piezoelectric vibrator of the ultrasonic probe, and transmission / reception control of the transmission / reception circuit A transmission / reception control circuit is provided.

  Furthermore, an image data conversion circuit that converts echo signals received by the transmission / reception circuit into ultrasonic image data of the subject is provided. Further, a display control circuit for controlling and displaying the monitor with the ultrasonic image data converted by the image data conversion circuit and a control circuit for controlling the entire ultrasonic medical image diagnostic apparatus are provided.

  A transmission / reception control circuit, an image data conversion circuit, and a display control circuit are connected to the control circuit, and the control circuit controls operations of these units. Then, an electrical signal is applied to each piezoelectric vibrator of the ultrasonic probe to transmit an ultrasonic wave to the subject, and the reflected wave caused by acoustic impedance mismatch inside the subject is detected by the ultrasonic probe. Receive at.

  The transmission / reception circuit corresponds to “means for generating an electrical signal”, and the image data conversion circuit corresponds to “image processing means”.

  According to the ultrasonic diagnostic apparatus as described above, by utilizing the characteristics of the ultrasonic receiving vibrator excellent in piezoelectric characteristics and heat resistance of the present invention and suitable for high frequency and wide band, the image quality and its An ultrasonic image with improved reproduction and stability can be obtained.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited to these.

(Example 1): Synthesis of polyurea having an amino group at the terminal (1)
0.085 mol of diamine, 0.085 mol of ammonium carbonate and 0.175 mol of triphenylphosphine were added to 500 ml of pyridine and stirred. The reaction solution was heated to 70 ° C., 0.175 mol of hexachloroethane was added, and the mixture was stirred at 70 ° C. for 24 hours. The reaction solution was added to a mixed solvent of methanol-acetone 1: 1, and the precipitate was collected by filtration. The precipitate was washed successively with water and methanol and dried under reduced pressure to obtain polyurea having an amino group at the terminal.

  The polyurea obtained and the diamine used are shown below.

<PU-2>
Weight average molecular weight 13,000 Molecular weight distribution 1.8
4,6-diamino-3,4,5,6-tetrahydro-2H-cyclopenta [d] thiazol-2-one
<PU-3>
Weight average molecular weight 10,000, molecular weight distribution 2.1
5,6-difluoro-2,3-dihydro-1H-indene-1,3-diamin
<PU-4>
Weight average molecular weight 8,000, molecular weight distribution 1.5
6,7-diamino-5,6,7,8-tetrahydronaphthalene-2,3-dicarbonitile
In this example, the weight average molecular weight (Mn) and the molecular weight distribution (Mw / Mn) were calculated by gel permeation chromatography (GPC) in the following manner. The measurement conditions are as follows.

Solvent: 30 mM LiBr in N-methylpyrrolidone Device: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgel SuperAWM-H x 2 (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Sample concentration: 1.0 g / L
Injection volume: 40 μl
Flow rate: 0.5 ml / min
Calibration curve: Standard polystyrene: PS-1 (manufactured by Polymer Laboratories) Mw = 580 to 2,560,000 calibration curves with 9 samples were used.

(Example 2): Synthesis of polyurea having an amino group at the terminal (2)
Under a nitrogen atmosphere, diisocyanate was dissolved in 10 times the amount of NMP and cooled to 0 ° C. A diamine twice the mole of diisocyanate was dissolved in 10 times the amount of NMP and added to the reaction solution. After stirring at 0 ° C. for 1 hour, the reaction solution was returned to room temperature and further stirred for 3 hours. The reaction solution was added dropwise to ethyl acetate-heptane, and the supernatant was removed by decantation. The residue was washed with ethyl acetate to obtain a polyurea having an amino group at the terminal. The obtained polyurea and the raw materials used are shown below.

<PU-6>
Weight average molecular weight 6,000, molecular weight distribution 2.0
1,3-di (thiophen-2-yl) -4,5,6,7-tetrahydrobenzo [c] thiophene-5,6-diamine
1,3-di (thiophen-2-yl) -4,5,6,7-tetrahydrobenzo [c] thiophene-5,6-diisocynate
<PU-11>
Weight average molecular weight 5,000, molecular weight distribution 2.2
1,2,3,4-tetrahydropentalene-1,3-diamine
1,2,3,4-tetrahydropentalene-1,3-diisothiocynate
<PU-12>
Weight average molecular weight 6,000, molecular weight distribution 1.6
4,6-diamino-3,4,5,6-tetrahydro-2H-cyclopenta [d] thiazol-2-one
4,6-diisothiocynate-3,4,5,6-tetrahydro-2H-cyclopenta [d] thiazol-2-one
<PU-18>
Weight average molecular weight 8,000, molecular weight distribution 1.8
1,1,3,3-tetrafluorooctahydro-1H-isochromene-5,7-diamin
1,1,3,3-tetrafluorooctahydro-1H-isochromene-5,7-disisothiocynate
(Example 3): Synthesis of polyurea having an isothiocyanate group at the terminal In a nitrogen atmosphere, diamine was dissolved in 10 times the amount of NMP and cooled to 0 ° C. 2 times mole diisothiocyanate of diamine was dissolved in 10 times amount of NMP and added to the reaction solution. After stirring at 0 ° C. for 1 hour, the reaction solution was returned to room temperature and further stirred for 3 hours. The reaction solution was added dropwise to ethyl acetate-heptane, and the supernatant was removed by decantation. The residue was washed with ethyl acetate to obtain polyurea having an isocyanate group at the terminal. The obtained polyurea and the raw materials used are shown below.

<PU-13>
Weight average molecular weight 7,000, molecular weight distribution 2.4
5,6-difluoro-2,3-dihydro-1H-indene-1,3-diamin
5,6-difluoro-2,3-dihydro-1H-indene-1,3-diisothiocynate
(Example 4): Synthesis of polyurea having a hydroxyl group at the terminal In a nitrogen atmosphere, diamine was dissolved in 10 times the amount of NMP and cooled to 0 ° C. 2 times mole diisothiocyanate of diamine was dissolved in 10 times amount of NMP and added to the reaction solution. After stirring at 0 ° C. for 1 hour, the reaction solution was returned to room temperature and further stirred for 3 hours. The reaction solution was added dropwise to ethyl acetate-heptane, and the supernatant was removed by decantation. The residue was washed with ethyl acetate to obtain polythiourea having an isothiocyanate group at the terminal. Further, in a nitrogen atmosphere, the polythiourea was dissolved in 10 times the amount of NMP and cooled to 0 ° C. Diol of 2 times the mole of diisothiocyanate was dissolved in 10 times the amount of NMP and added to the reaction solution. After stirring at 0 ° C. for 1 hour, the reaction solution was returned to room temperature and further stirred for 3 hours. The reaction solution was added dropwise to ethyl acetate-heptane, and the supernatant was removed by decantation. The residue was washed with ethyl acetate to obtain polythiourea having a hydroxy group at the terminal. The obtained polythiourea and raw materials used are shown below.

<PU-14>
Weight average molecular weight 17,000, molecular weight distribution 2.4
5,6-difluoro-2,3-dihydro-1H-indene-1,3-diamin
5,6-difluoro-2,3-dihydro-1H-indene-1,3-diisothiocynate
Example 5: Production of resin composition film (1)
Under a nitrogen atmosphere, polyurea or polythiourea was dissolved in NMP, and the reaction solution was cooled to 0 ° C. An equimolar amount of macromonomer relative to the weight average molecular weight of polyurea was dissolved in NMP and added to the reaction solution. After the addition, the mixture was stirred at 0 ° C. for 1 hour, and then the internal temperature was gradually raised to 70 ° C. and further stirred for 3 hours. The obtained reaction liquid was added dropwise to methanol, and the supernatant was removed with decane, followed by vacuum drying, to obtain resin compositions-1 to 9. The weight average molecular weight and molecular weight distribution were determined in terms of polystyrene by measuring GPC as described above.

  These obtained resin compositions were applied and dried on a 25 μm polyimide film that had been pre-deposited on the surface with a 1% methanol solution of polyvinyl alcohol having a polymerization degree of 500 so that the dry film pressure would be 0.1 μm. The applied substrate was applied and dried so that the dry film pressure was 7 μm. Next, after an aluminum electrode is attached by vapor deposition to the surface of the substrate on which the film of the resin composition is thus formed, 100MV is used by using a high voltage power supply device HARB-20R60 (manufactured by Matsusada Precision Co., Ltd.). In a state where an electric field of / m is applied, the temperature rises to 200 ° C. at a rate of 5 ° C./min. After holding at 200 ° C. for 15 minutes, the voltage is applied and then gradually cooled to room temperature and subjected to poling treatment to obtain a resin composition Material films-1 to 9 were produced. In addition, since the said resin composition film | membrane is equipped with the electrode, it can be used with an ultrasonic transducer | vibrator. The same applies hereinafter.

(Comparative Example 1): Preparation of Comparative Resin Composition Film-1 9H-fluorene-2,7-diisocyanate and 2- (2), which are the same raw materials as the macromonomer used in Resin Composition Film-5 of Example 4 -Aminoethoxy) ethanol was used at a molar ratio of 1: 2 and the following operation was performed.

  Under a nitrogen atmosphere, polyurea (PU-1) was dissolved in NMP, and the reaction solution was cooled to 0 ° C. An equimolar amount of 9H-fluorene-2,7-diisocyanate and 2-fold mol of 2- (2-aminoethoxy) ethanol with respect to the weight average molecular weight of PU-1 were each dissolved in NMP and added simultaneously to the reaction solution. After the addition, the mixture was stirred at 0 ° C. for 1 hour, and then the internal temperature was gradually raised to 70 ° C. and further stirred for 3 hours. After removing components insoluble in NMP by filtration, the reaction solution was added dropwise to methanol, and the supernatant was removed with decane. The residue was vacuum dried to obtain Comparative Resin Composition-1. The weight average molecular weight and molecular weight distribution were determined in terms of polystyrene by measuring GPC as described above.

  The obtained resin composition was applied and dried on a 25 μm polyimide film that had been vapor-deposited on the surface in advance with a 1% methanol solution of polyvinyl alcohol having a polymerization degree of 500 so that the dry film pressure was 0.1 μm. Coating and drying were performed on the substrate so that the dry film pressure was 7 μm. Next, after an aluminum electrode is attached by vapor deposition to the surface of the substrate on which the film of the resin composition is thus formed, 100MV is used by using a high voltage power supply device HARB-20R60 (manufactured by Matsusada Precision Co., Ltd.). In a state where an electric field of / m is applied, the temperature is increased to 200 ° C. at a rate of 5 ° C./min. After holding at 200 ° C. for 15 minutes, the voltage is applied and then gradually cooled to room temperature, and subjected to a poling treatment for comparison resin Composition film-1 was produced.

(Comparative Example 2): Preparation of Comparative Resin Composition Film-2 Comparative Polymer Composition Film-2 was prepared in the same manner as in Example 4 using polyethylene glycol (PEG 2,000) having a molecular weight of 2,000 as a macromonomer. Produced.

(Comparative Example 3): Preparation of Comparative Resin Composition Film-3 Under a nitrogen atmosphere, terephthaloyl dichloride was dissolved in NMP, and the reaction solution was cooled to 0 ° C. NMP in which terephthaloyl dichloride and an equimolar amount of 3,5-diaminobenzoic acid were dissolved was added, and the reaction solution was returned to room temperature and stirred for 1 hour. Furthermore, the same amount of terephthaloyl dichloride dissolved in NMP was added and stirred for 15 minutes to obtain an NMP solution of polyamide (A) having an acid halide at the end group.

  The NMP solution of polyamide (A) was cooled to 0 ° C., and the macromonomer (M-38) dissolved in NMP was added. After the addition, the mixture was stirred at 0 ° C. for 1 hour, and then the internal temperature was gradually raised to 70 ° C. and further stirred for 3 hours. The obtained reaction liquid was dropped into methanol, the supernatant was removed with decane, and vacuum-dried to obtain comparative resin composition-3.

  The obtained resin composition was applied and dried on a 25 μm polyimide film that had been pre-deposited on the surface with a methanol solution of polyvinyl alcohol having a polymerization degree of 1% of 500% so that the dry film pressure was 0.1 μm. Coating and drying were performed on the substrate so that the dry film pressure was 7 μm. Next, after an aluminum electrode is attached by vapor deposition to the surface of the substrate on which the film of the resin composition is thus formed, 100MV is used by using a high voltage power supply device HARB-20R60 (manufactured by Matsusada Precision Co., Ltd.). In a state where an electric field of / m is applied, the temperature is increased to 200 ° C. at a rate of 5 ° C./min. After holding at 200 ° C. for 15 minutes, the voltage is applied and then gradually cooled to room temperature and subjected to a poling treatment for comparison resin Composition film-3 was produced.

(Comparative Example 4): Preparation of Comparative Resin Composition Film-4 2,2-dimethyl-1 in place of 2,2-dimethyl-1,3-propanediamine used in Polyurea (PU-57) of Example 3 Except for using 1,3-propanediol, the same operation was performed to obtain a polyurethane (A) having an isocyanate group at the terminal.

  The obtained polyurethane (A) was used in place of polyurea, and a comparative resin composition film-4 was obtained in the same manner as in Example 4.

(Example 6): Evaluation of Resin Composition Film Using the obtained resin composition films as an ultrasonic vibrator, the piezoelectricity was evaluated by a resonance method in a state heated to room temperature and 100 ° C. In addition, a piezoelectric characteristic is shown as a relative value with the value when measured at room temperature of the PVDF film as 100%.

  The measurement results and the like are summarized in Table 2.

  As is apparent from the results shown in Table 2, the piezoelectric characteristics of the organic piezoelectric film formed from the resin composition formed using polyurea and the macromonomer of the present invention are superior to those of the comparative example. I understand.

(Example 7)
(Preparation and evaluation of ultrasonic probe)
<Production of piezoelectric material for transmission>
Component raw materials CaCO ₃ , La ₂ O ₃ , Bi ₂ O ₃ and TiO ₂ , and subcomponent raw materials MnO are prepared, and for the component raw materials, the final composition of the components is (Ca _{0. 97} La _{0.0 3} . ) Bi ₄ . Weighed to be ₀₁ Ti ₄ O ₁₅ . Next, pure water was added, mixed in a ball mill containing zirconia media in pure water for 8 hours, and sufficiently dried to obtain a mixed powder. The obtained mixed powder was temporarily molded and calcined in air at 800 ° C. for 2 hours to prepare a calcined product. Next, pure water was added to the obtained calcined material, finely pulverized in a ball mill containing zirconia media in pure water, and dried to prepare a piezoelectric ceramic raw material powder. In pulverization, the piezoelectric ceramic raw material powder having a particle diameter of 100 nm was obtained by changing the pulverization time and pulverization conditions. 6% by mass of pure water as a binder is added to each piezoelectric ceramic raw material powder having a different particle diameter, press-molded to form a plate-shaped temporary molded body having a thickness of 100 μm, and this plate-shaped temporary molded body is vacuum-packed and then 235 MPa. It shape | molded by the press with the pressure of. Next, the molded body was fired. The final sintered body had a thickness of 20 μm. The firing temperature was 1100 ° C. An electric field of 1.5 × Ec (MV / m) or more was applied for 1 minute to perform polarization treatment.

<Production of laminated resonator for reception>
A laminated vibrator was produced in which the organic piezoelectric film produced in Example 1 and a polyester film having a thickness of 50 μm were bonded together with an epoxy adhesive. Thereafter, polarization treatment was performed in the same manner as described above.

  Next, according to a conventional method, an ultrasonic probe was prototyped by laminating a laminated receiver for reception on the above-described piezoelectric material for transmission and installing a backing layer and an acoustic matching layer.

  As a comparative example, in place of the above laminated resonator for reception, a laminated resonator for reception using only a polyvinylidene fluoride copolymer film (organic piezoelectric film) was laminated on the above laminated resonator. A probe similar to the above-described ultrasonic probe was produced.

  Next, the above two types of ultrasonic probes were evaluated by measuring the reception sensitivity and the dielectric breakdown strength.

Incidentally, the reception sensitivity is originating the fundamental frequency _{f 1} of 5 MHz, to determine the received relative sensitivity of 20MHz as 15 MHz, 4 harmonics as received second harmonic wave _{f 2} as 10 MHz, 3 harmonic. For the relative sensitivity of reception, a sound intensity measurement system Model 805 (1 to 50 MHz) manufactured by Sonora Medical System, Inc. (2021 Miller Drive Longmont, Colorado (0501 USA)) was used.

  The dielectric breakdown strength was measured by multiplying the load power P by 5 times, testing for 10 hours, and then returning the load power to the reference to evaluate the relative reception sensitivity. The sensitivity was evaluated as good when the decrease in sensitivity was within 1% before the load test, more than 1% and less than 10%, and 10% or more as bad.

  In the above evaluation, the ultrasonic probe provided with the receiving piezoelectric (body) laminated vibrator according to the present invention has a relative receiving sensitivity about 1.2 times that of the comparative example, and has a dielectric breakdown. It was confirmed that the strength was good. That is, it was confirmed that the ultrasonic wave receiving transducer of the present invention can be suitably used for a probe used in an ultrasonic medical image diagnostic apparatus as shown in FIG.

1 Receiving piezoelectric material (film)
2 Support 3 Piezoelectric material for transmission (film)
4 Backing layer 5 Electrode 6 Acoustic lens

Claims (9)

A polymer formed by a polymerization reaction of a macromonomer having at least two kinds of bonds containing any one of a nitrogen atom, an oxygen atom, and a sulfur atom and a polyurea, and having a glass transition temperature of 100 to 180 ° C An organic piezoelectric material comprising a polymer in the range of The organic piezoelectric material according to claim 1, wherein the polymer has an aliphatic ring in the main chain. 3. The organic piezoelectric material according to claim 1, wherein at least one end of the chemical structure of the macromonomer is a polymerizable functional group. The organic piezoelectric material according to any one of claims 1 to 3, wherein an electromechanical coupling constant of the organic piezoelectric material is 0.20 or more. The organic piezoelectric material according to any one of claims 1 to 4, wherein the organic piezoelectric material is polarized by an electric field or a combination of an electric field and a magnetic field. An ultrasonic transducer comprising the organic piezoelectric material according to any one of claims 1 to 4 and an electrode. An ultrasonic probe comprising the ultrasonic transducer according to claim 6. The ultrasonic probe according to claim 7, wherein the ultrasonic transducer is a receiving ultrasonic transducer. An ultrasonic medical image diagnostic apparatus comprising the ultrasonic probe according to claim 7.

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