WO2009116356A1

WO2009116356A1 - Organic piezoelectric material, organic piezoelectric film, ultrasonic vibrator, ultrasonic probe, and ultrasonic image diagnosis apparatus for medical application

Info

Publication number: WO2009116356A1
Application number: PCT/JP2009/053182
Authority: WO
Inventors: 雄一西久保
Original assignee: コニカミノルタエムジー株式会社
Priority date: 2008-03-17
Filing date: 2009-02-23
Publication date: 2009-09-24

Abstract

This invention provides an organic piezoelectric material that has improved film slipperiness and scratch resistance in producing a large-area organic piezoelectric film and, at the same time, has excellent piezoelectric properties and heat resistance, an organic piezoelectric film using the organic piezoelectric material, an ultrasonic vibrator, an ultrasonic probe, and an ultrasonic image diagnosis apparatus for medical application. The organic piezoelectric material is characterized by containing fine particles of an inorganic metal oxide that has been surface-treated with an organic surface treating agent.

Description

Organic piezoelectric material, organic piezoelectric film, ultrasonic transducer, ultrasonic probe, and ultrasonic medical diagnostic imaging apparatus

The present invention relates to an organic piezoelectric material having improved piezoelectric properties and slipperiness and scratch resistance when producing a large-area organic piezoelectric film, an organic piezoelectric film using the same, an ultrasonic vibrator, an ultrasonic transducer The present invention relates to an acoustic probe and an ultrasonic medical image diagnostic apparatus.

Ultrasonic probes are rapidly used as non-destructive inspection devices as well as medical ultrasonic diagnostic devices. 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. This harmonic imaging technology has (1) a low sidelobe level compared to the level of the fundamental frequency component, an improved S / N ratio (signal to noise ratio) and improved contrast resolution, and (2) frequency 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).

Such an ultrasonic probe uses a piezoelectric body that generates ultrasonic waves. Conventionally, as a piezoelectric body, a so-called inorganic material in which a single crystal such as quartz, LiNbO ₃ , LiTaO ₃ , 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 Documents 2 and 3). 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, when manufacturing large-area films and thin films with this piezoelectric polymer material, it is difficult to transport in the process due to low density and low elasticity, and the film is damaged during friction and contact with the roller, resulting in a decrease in yield. There was a problem to do.
Japanese Patent Laid-Open No. 11-276478 JP-A-6-216422 Japanese Patent Laid-Open No. 2008-36202

The present invention has been made in view of the above-mentioned problems and situations, and the solution is to improve the slipperiness and scratch resistance of the film when producing a large-area organic piezoelectric film, and to have excellent piezoelectric characteristics. An organic piezoelectric material, an organic piezoelectric film using the same, an ultrasonic transducer, an ultrasonic probe, and an ultrasonic medical diagnostic imaging apparatus are provided.

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

1. An organic piezoelectric material comprising inorganic metal oxide fine particles surface-treated with an organic surface treatment agent.

2. 2. The organic piezoelectric material as described in 1 above, wherein the organic surface treating agent has at least one of an alkyl group or an aryl group having 2 to 20 carbon atoms.

3. 3. The organic piezoelectric material as described in 1 or 2 above, wherein the inorganic metal oxide fine particles are fine particles containing an inorganic piezoelectric material.

4). Wherein the inorganic metal oxide particles, quartz, LiNbO _3, LiTaO _3, a single crystal of KNbO _3, ZnO, or Pb (Zr, Ti) a 3, characterized in that the fine particles containing sintered body of O ₃ The organic piezoelectric material described in 1.

5. Any one of the above 1 to 4, wherein the organic piezoelectric material is formed of a polymer material having a urea structure or a thiourea structure, or a composite material containing the polymer material having a urea structure or a thiourea structure. The organic piezoelectric material according to one item.

6. Any one of the above 1 to 5, wherein the organic piezoelectric material is formed of a polymer material mainly containing polyvinylidene fluoride or a composite material containing a polymer material mainly containing polyvinylidene fluoride. The organic piezoelectric material according to one item.

7. 7. An organic piezoelectric film using the organic piezoelectric material according to any one of 1 to 6 above.

8. 7. An ultrasonic transducer using the organic piezoelectric material according to any one of 1 to 6 as an organic piezoelectric film.

9. 7. An ultrasonic probe comprising an ultrasonic transmission transducer and an ultrasonic reception transducer, wherein the ultrasonic transducer is formed using the organic piezoelectric material according to any one of 1 to 6 above. An ultrasonic probe characterized by using as a transducer for ultrasonic reception.

10. Ultrasound in which a means for generating an electrical signal and a plurality of transducers for receiving the electrical signal and transmitting an ultrasonic wave toward the subject and generating a reception signal corresponding to the reflected wave received from the subject are arranged In the ultrasonic medical image diagnostic apparatus, comprising: an ultrasonic probe; and an image processing unit that generates an image of the subject according to the reception signal generated by the ultrasonic probe. An ultrasonic medical diagnostic imaging apparatus using the ultrasonic probe formed using the organic piezoelectric material according to any one of 1 to 6 above.

By the above means of the present invention, an organic piezoelectric material having improved piezoelectric properties and slipperiness and scratch resistance when producing a large area organic piezoelectric film, an organic piezoelectric film using the same, and ultrasonic vibration A child, an ultrasonic probe, and an ultrasonic medical image diagnostic apparatus can be provided.

That is, from the viewpoint of the mechanism of action, when manufacturing an organic piezoelectric film from an organic piezoelectric material, it is difficult to carry it in the process when manufacturing a large-area thin film using the low density and low elasticity of the organic piezoelectric material. There is a problem that the film is damaged and the yield is lowered at the time of friction and contact with the roller, and the advantage of the organic piezoelectric material cannot be utilized.

However, in the present invention, by mixing inorganic metal oxide fine particles surface-treated with an organic surface treatment agent in an organic piezoelectric material, friction during contact with a roller or the like during transportation of the organic piezoelectric film is suppressed. Therefore, even a thin film with a large area can be smoothly conveyed without being damaged.

In addition, by covering the surface of the fine particles with an organic substance, the fine particles themselves can be prevented from aggregating, whereby the above problem can be solved with a minimum necessary addition amount. Accordingly, it is possible to provide an organic piezoelectric material, an organic piezoelectric film, an ultrasonic transducer, an ultrasonic probe, and an ultrasonic medical image diagnostic apparatus that take advantage of the original characteristics.

Process drawing which shows an example of the manufacturing apparatus of the organic piezoelectric material of this invention Conceptual diagram showing the configuration of the main part of an ultrasonic medical diagnostic imaging apparatus Appearance block diagram of ultrasonic medical diagnostic imaging equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic piezoelectric material liquid tank 1a Organic piezoelectric material liquid 2 Fine particle additive liquid tank 2a Fine particle additive liquid 3 Additive liquid tank 3a

Additive liquid

4a, 4b, 4c,

4d Pump

5a, 5b In-line mixer 6 Slit die 7 Drum 8 Casting Belt 9 Roller 10 Organic piezoelectric material P1 Receiving piezoelectric material (film)
P2 Support P3 Transmission piezoelectric material (film)
P4 Backing layer P5 Electrode P6 Acoustic lens S Ultrasound medical image diagnostic device S1 Body of ultrasonic medical image diagnostic device S2 Ultrasonic probe S3 Operation input unit S4 Display unit

The organic piezoelectric material of the present invention is characterized by containing inorganic metal oxide fine particles surface-treated with an organic surface treatment agent. This feature is a technical feature common to the inventions according to claims 1 to 10.

As an embodiment of the present invention, the organic surface treating agent is preferably an embodiment having at least one of an alkyl group having 2 to 20 carbon atoms or an aryl group. The inorganic metal oxide fine particles are preferably fine particles containing an inorganic piezoelectric material. In particular, the inorganic metal oxide fine particles are preferably fine particles containing a sintered body of quartz, LiNbO ₃ , LiTaO ₃ , KNbO ₃ single crystal, ZnO, AlN, or Pb (Zr, Ti) O _3. .

Furthermore, in the present invention, the organic piezoelectric material may be formed of a polymer material having a urea structure or a thiourea structure, or a composite material containing a polymer material having the urea structure or thiourea structure. preferable. Alternatively, it is preferably 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.

The organic piezoelectric material of the present invention is suitable as a material for forming an organic piezoelectric film because it has the characteristics of excellent piezoelectric characteristics and heat resistance. The organic piezoelectric film can be suitably used for an ultrasonic vibrator. In particular, an ultrasonic probe including an ultrasonic transmission transducer and an ultrasonic reception transducer can be suitably used as an ultrasonic reception transducer. Furthermore, this ultrasonic probe can be used for an ultrasonic medical image diagnostic apparatus. For example, means for generating an electrical signal and a plurality of transducers that receive the electrical signal and transmit an ultrasonic wave toward the subject and generate a reception signal corresponding to the reflected wave received from the subject are arranged. In the ultrasonic medical image diagnostic apparatus, comprising: an ultrasonic probe; and an image processing unit that generates an image of the subject according to the reception signal generated by the ultrasonic probe. It can be suitably used as a touch element.

Hereinafter, the present invention, its components, and the best modes and modes for carrying out the invention will be described in detail.

(Inorganic metal oxide fine particles)
Examples of the inorganic metal oxide constituting the inorganic metal oxide fine particles according to the present invention include oxidation of metal elements such as Li, K, Al, Mg, Si, Ta, Nb, Ti, Zr, Fe, Mn, Pb, and Zn. Or compounds containing these oxides as main components and containing other elements can be used. Here, the main component means a component having the largest content (mass%) among the components constituting the particles.

Specific examples include silicon oxide, aluminum oxide, magnesium oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate. be able to.

In the present invention, since the inorganic metal oxide is mixed with the organic piezoelectric material, a material having piezoelectricity is particularly preferable. That is, an inorganic metal oxide formed from a quartz crystal generally known as a piezoelectric material, a single crystal of LiNbO ₃ , LiTaO ₃ , KNbO ₃ , a sintered body of ZnO, AlN, Pb (Zr, Ti) O ₃ Is preferable in that the piezoelectricity of the organic piezoelectric material is not impaired.

In the present invention, the inorganic metal oxide needs to be used as fine particles. The microparticulation can be carried out by a general pulverization method, but it is preferable that the microparticles used in the present invention have a uniform monodisperse particle size.

The mass average diameter of the primary particles of the inorganic metal oxide fine particles is preferably 1 to 150 nm, more preferably 1 to 100 nm, and most preferably 1 to 80 nm. The average particle diameter of the metal oxide fine particles is measured by a light scattering method if it is 20-30 nm or more, and by an electron micrograph if it is 20-30 nm or less.

The specific surface area of the metal oxide fine particles is preferably 10 to 400 m ² / g, more preferably 20 to 200 m ² / g, and more preferably 30 to 150 m ² / g, as measured by the BET method. Most preferably it is.

(Organic surface treatment agent)
The metal oxide fine particles according to the present invention must be surface-treated with an organic surface treatment agent.

As the organic surface treatment agent, various surface treatment agents conventionally used as a surface treatment agent for metal oxide fine particles can be used. In the present invention, it is particularly preferable to use a silane coupling agent or a titanium coupling agent.

The silane coupling agent or the titanium coupling agent is preferably a compound represented by the following general formula (Si) or general formula (Ti).

General formula (Si): (X ₁ ) _n1 -Si- (R ₁ ) _4-n1
General formula (Ti): (X ₂ ) _n2 -Ti- (R ₂ ) _4-n2
In the formula, X ₁ and X ₂ represent a halogen group and an alkoxy group having 1 to 20 carbon atoms, R ₁ and R ₂ represent an alkyl group, an alkenyl group and an allyl group having 1 to 45 carbon atoms, and n1, n ₂ represents an integer of 1 to 3.

In the general formula (Si) and general formula (Ti), preferred X ₁ and X ₂ represent a halogen group, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, and more preferred are Cl, —OR ₃ (R ₃ represents an alkyl group having 8 or less carbon atoms). Among them, particularly preferred X ₁ and X ₂ are Cl, methyloxy, ethyloxy, propyloxy, isopropyloxy, butyloxy, cyclohexyloxy, chloroethyloxy, benzyloxy, and ethylenedioxy, especially Cl, methyloxy, ethyloxy, isopropyl Oxy and butyloxy are preferred.

R ₁ and R 2 are preferably — (CH ₂ ) _m1 — (Y) _n1 —R ₄ , where Y is —O—, —S—, —NH—, —CO—, — CONH -, - NHCO -, - SO 2 -, - SO 2 NH -, - NHSO 2 -, - C 6 H 5 - represents, R ₄ is _{_{H, C m2 H 2m2 + 1}} , C m2 H 2m2 - 1 -CH = CH ₂ , -CH (CH ₃ ) = CH ₂ , -N (R ₅ ) ₂ , -N (+) (R ₅ ) ₃ .Z (-),-[(CH ₂ ) _{m 3} O] _{m 4} —R ₆ , — (CH ₂ CH (OH) CH ₂ O) _m4 —R ₆ , — (CF ₂ ) _m ₂ F, — (CH ₂ ) _m ₂ C ₆ H ₅ , epoxy, glycidyl, —NCO, —COOM, —SO ₃ M, —C ₆ H ₅ —R ₅ , —P (═O) OP (═O) O (OR ₅ ) ₂ is represented.

R ₅ is an alkyl group having 1 to 10 carbon atoms, R ₆ is R ₅ or —COR ₅ , Z is Cl or Br, m ₁ is 0 to 40, m ₂ is 1 to 30, m ₃ is 1 -6, m ₄ represents 1-36, and n ₁ represents 0, ₁ , 2. M is Na, K, H, NH ₄ .

Specific compounds represented by general formula (Si) and general formula (Ti) of the present invention are shown below, but are not limited thereto.

Examples of the compound represented by the general formula (Si) include vinyltrichlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-β (aminoethyl) γ- Aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, vinyloctyltrimethoxysilane, 10- (vinyloxycarbonyl) nonyltrimethoxysilane, p-vinylphenyltriisopropylsilane, 3- (glycidyloxy) Propyltriethoxysilane, 3- (acryloyl) propyltrimethoxysilane, 11- (methacryloyl) undecyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-N, N-dibutylaminopropyltrimethoxysilane, 3-trimethylammoniopropyltrimethoxylane iodide, 3-mercaptopropyltrimethoxylane, 3-isocyanylpropylmethyldimethoxylane, 3- (poly (degree of polymerization 10) ) Oxyethynyl) oxypropyltrimethoxylane, 3-methoxy (poly (degree of polymerization 6) oxyethynyl) oxypropyltrimethoxylane, and the like.

Examples of the compound represented by the general formula (Ti) include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctylpyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditri) Decylphosphite) titanate, tetra (2,2′-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, Isopropyltrioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate, isopropylisostearoyl diacrylate Titanate, isopropyl tri (dioctyl phosphate) Chitaneto, isopropyl tricumylphenyl titanate, isopropyl tri (N- amidoethyl-aminoethyl) titanate, dicumyl phenyloxy acetate titanate, may be mentioned diisostearoyl ethylene titanate or the like.

In the present invention, among the above organic surface treatment agents, it is particularly preferable to use an organic surface treatment agent having at least one of an alkyl group having 2 to 20 carbon atoms or an aryl group.

It is presumed that the effect of the present invention, such as improvement of scratch resistance, can be more easily exerted by setting the carbon number to 2-20, more preferably 10-20, so that the fine particles and the organic piezoelectric material are easily adapted.

In attaching the silane coupling agent, titanium coupling agent and the like to the metal oxide fine particles coated with the metal oxide particles, a known method can be used.

For example, using a Henschel mixer, super mixer, ready mixer, V-type blender, open kneader, or other stirrer, a dry method in which a silane coupling agent or the like is added dropwise or sprayed while stirring and mixing metal oxide fine particles such as titanium oxide, slurry type Stirring while dropping a silane coupling agent, etc. on the metal oxide fine particles, and after completion of the dropping, the metal oxide fine particles are precipitated, filtered and dried to remove the residual solvent, and the metal oxide fine particles are dispersed in the solvent. After adding and stirring a silane coupling agent, etc. here, a method of forming an adhesion layer by evaporating the solvent or an organic piezoelectric material coating dispersion containing metal oxide fine particles or the like. It is a method of adding it.

In order to ensure the reaction between the silane coupling agent and the metal oxide fine particles, it is desirable to dry at 60 to 130 ° C. for about 10 to 200 minutes.

The shape of the inorganic metal oxide fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape.

The inorganic metal oxide fine particles are used for forming an organic piezoelectric material in a dispersion state. Examples of the dispersion medium of the inorganic metal oxide fine particles include hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), and aromatic hydrocarbons (eg, benzene). , Toluene, xylene), alcohols (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), esters (eg, methyl acetate, ethyl acetate, Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), glycol ethers (methyl cellosolve, ethyl cellosolve), other organic solvents, or a mixture of these in an organic solvent Can be distributed and used That. Propylene glycol monoalkyl ether (1 to 4 carbon atoms in the alkyl group) or propylene glycol monoalkyl ether acetate ester (1 to 4 carbon atoms in the alkyl group) is 5% by mass or more, more preferably 5 to 80%. It is preferable to use the organic solvent containing at least mass%.

The metal oxide fine particles can be dispersed in these media using a disperser. Examples of dispersers include sand grinder mills (eg, pinned bead mills), high speed impeller mills, pebble mills, roller mills, attritors and colloid mills. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

Examples of the method for preparing a dispersion of inorganic metal oxide fine particles (hereinafter simply referred to as “fine particles”) according to the present invention include the following three types.

(Preparation method A)
After stirring and mixing the solvent and fine particles, dispersion is performed with a disperser. This is a fine particle dispersion. The fine particle dispersion is added to the organic piezoelectric material liquid and stirred.

(Preparation method B)
After stirring and mixing the solvent and fine particles, dispersion is performed with a disperser. This is a fine particle dispersion. Separately, a small amount of an organic piezoelectric material (for example, PVDF, polyurea resin, polythiourea resin) is added to the solvent and dissolved by stirring. The fine particle dispersion is added to this and stirred. This is a fine particle addition solution. The fine particle addition liquid is sufficiently mixed with the organic piezoelectric material liquid by an in-line mixer.

(Preparation method C)
A small amount of organic piezoelectric material (for example, PVDF, polyurea resin, polythiourea resin) is added to the solvent, and dissolved by stirring. Fine particles are added to this and dispersed by a disperser. This is a fine particle addition solution. The fine particle addition liquid is sufficiently mixed with the organic piezoelectric material liquid by an in-line mixer.

Preparation method A is excellent in fine particle dispersibility, and preparation method C is excellent in that the fine particles are difficult to re-aggregate. Preparation method B is a preferred preparation method that is excellent in both dispersibility of the fine particles and that the fine particles are difficult to reaggregate.

(Distribution method)
When the fine particles are mixed with a solvent and dispersed, the concentration of the fine particles is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and most preferably 15 to 20% by mass. A higher dispersion concentration is preferred because the turbidity with respect to the amount added tends to be low and aggregates are reduced.

Solvents used include alcohols such as methyl alcohol and ethyl alcohol, ketones such as acetone and methyl ethyl ketone, aromatics such as benzene, toluene and xylene, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone and the like Any of these can be preferably used. It is preferable that the organic piezoelectric material used (for example, PVDF, polyurea resin, polythiourea resin) is a solvent in which at least 5% by mass is dissolved.

The amount of fine particles added to the organic piezoelectric material is preferably 0.01 to 10% by mass, and more preferably 0.05 to 3% by mass with respect to the mass of the organic piezoelectric material.

Disperser can be a normal disperser. Dispersers can be broadly divided into media dispersers and medialess dispersers. For dispersion of silicon dioxide fine particles, a medialess disperser is preferable because it can reduce aggregates.

Examples of the media disperser include a ball mill, a sand mill, and a dyno mill. Examples of the medialess disperser include an ultrasonic type, a centrifugal type, and a high pressure type. In the present invention, a high pressure disperser is preferable. The high pressure dispersion device is a device that creates special conditions such as high shear and high pressure by passing a composition in which fine particles and a solvent are mixed at high speed through a narrow tube. When processing with a high-pressure dispersion apparatus, for example, the maximum pressure condition inside the apparatus is preferably 9.81 × 10 ⁶ Pa (100 kgf / cm ² ) or more in a thin tube having a tube diameter of 1 to 2000 μm. More preferably, it is 1.96 × 10 ⁷ Pa (200 kgf / cm ² ) or more. Further, at that time, those having a maximum reaching speed of 100 m / second or more and those having a heat transfer speed of 100 kcal / hour or more are preferable. The high-pressure dispersion apparatus as described above includes an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by Microfluidics Corporation or a nanomizer manufactured by Nanomizer. For example, UHN-01 manufactured by Wakki Co., Ltd. may be used.

<Organic polymer materials constituting organic piezoelectric materials>
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 an aromatic heterocyclic sulfonyl group (for example, trifluoromethanesulfonyl, methanesulfonyl, benzenesulfonyl), a carbamoyl group (for example, carbamoyl, methylcarbamoyl, phenylcarbamoyl, 2-chloro-phenylcarbamoyl), alkoxycarbon Groups (eg methoxycarbonyl, ethoxycarbonyl, diphenylmethylcarbonyl), substituted aryl groups (eg pentachlorophenyl, pentafluorophenyl, 2,4-dimethanesulfonylphenyl, 2-trifluoromethylphenyl), aromatic heterocyclic groups (eg 2-benzoxazolyl, 2-benzthiazolyl, 1-phenyl-2-benzimidazolyl, 1-tetrazolyl), azo group (eg phenylazo), ditrifluoromethylamino group, trifluoromethoxy group, alkylsulfonyloxy group (eg methane) Sulfonyloxy), 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- Diethylsulfamoyl) 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-t-butylaniline), 4,4'-methylenebis (2-cyclohexylaniline), 4,4 ' -Methylenebis (3,5-dimethylaniline), 4,4'-methylenebis (2,3-dimethylaniline), 4,4'-methylenebis (2,5-dimethyl) Aniline), 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-a Nophenyl) 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′-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, , 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′-dia Minodiphenyl 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 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-aminophenyl) Diamine compounds such as methyl) -1H-pyrrole, 1- (di-p-aminophenylmethyl) -1H-imidazole, 2- (di-p-aminophenylmethyl) oxazole and derivatives thereof, and 4,4′-diphenylmethane diisocyanate Nart (MDI), 4,4'-methylenebis (2,6-dimethylphenyl isocyanate), 4,4'- Tylene bis (2,6-diethylphenyl isocyanate), 4,4′-methylene bis (2,6-di-t-butylphenyl isocyanate), 4,4′-methylene bis (2,6-dicyclohexylphenyl isocyanate), 4,4′-methylenebis (2-methylphenyl isocyanate), 4,4′-methylenebis (2-ethylphenyl isocyanate), 4,4′-methylenebis (2-t-butylphenyl isocyanate), 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′-methylene bis (2,6-dichlorophenyl isocyanate), 4,4′-methylene bis (2-chlorophenyl isocyanate), 4,4′-methylene bis (2,3-dibromophenyl isocyanate), m- Xylylene diisocyanate, 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 Diisocyanate (2,6-TDI), 1,3-bis (2-isocyanato-2-propyl) benzene, 1,3-bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane-4,4′-diisocyanate Narate, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, 2,7-fluorenediocyanate, benzophenone-4,4'-diisocyanate, 3,3'-dichlorobenzophenone-4,4'- Diisocyanic 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) Natephenyl) hexafluoropropane, 2,2-bis (3-fluoro-4-isocyanatophenyl) hexafluoropropane, bis (4-isocyanatephenyl) ether, bis (3,5-difluoro-4-isocyanatophenyl) ether, Bis (4-isocyanatephenyl) sulfide, bis (3,5-dibromo-4-isocyanatephenyl) sulfide, bis (4-isocyanatephenyl) disulfide, bis (4-isocyanatephenyl) sulfone, bis (4-isocyanatephenyl) 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-isocyanatophenylmethyl) ) Diisocyanate conversion such as oxazole Compounds 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'-diisothiocyanate, 3,3'-difluorobenzophenone-4,4'-diisothiocyanate, , 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) Oxide, 1,1-bis (4-isothiocyanatophenyl) cyclopropane, 1,1-bis (4-isothiocyanatophenyl) cyclooctane, 4,4 ′-(cyclohexylmethylene) bis (isothiocyanatebenzene), 2, Diisothiocyanate compounds such as diethyl 2-bis (4-isothiocyanatephenyl) malonate, 1- (di-p-isothiocyanatephenylmethyl) -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 preferable that the compound represented by the formula or a derivative of these compounds is used as a raw material.

(Wherein R ₁₁ and R ₁₂ each independently represents a hydrogen atom, an alkyl group, a 3- to 10-membered non-aromatic ring 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.)

(Wherein R ₁₃ each 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 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. to .R ₂₁ ~ R ₂₆ represents R ₂₁ ~ R ₂₆ group having the same meaning as in formula (5).)

(Wherein, Y each independently represents a keto group, an oxime group, a substituted vinylidene group, R ₂₁ ~ R ₂₆ represents R ₂₁ ~ 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) >>
Examples of the compound represented by the general formula (3) include 9,9-dimethyl-2,7-diaminofluorenone, 2,7-diamino-9-benzylfluorenone, and 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 not be present, 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. 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 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 having a valence of X 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 -(Perfluorobenzenesulfonyloxy) styrene, (4-vinylphenyl) bis (trifluoromethanesulfonyl) amide, and the like, but are not limited thereto.

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

《Macromonomer》
In the present invention, it is also a preferred embodiment that the compound having a urea bond or thiourea bond is formed from a macromonomer having a molecular weight of 400 to 10,000 as a raw material.

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 ₃ CSNR ₄ -), urethane bond (-OCONR ₁ -), an amide bond (-CONR ₁ -), ether bond (-O-), an ester bond (-CO ₂ -) and carbonate A compound having two or more bonds selected from a bond (—CO ₂ —).

In the present application, R ₁ in the “urethane bond” is 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, A cyclohexyl group or the like, preferably a hydrogen atom or an alkyl group having 5 or less carbon atoms, more preferably a hydrogen atom or a methyl group. R ₁ in the “amide bond” is 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.) And preferably a hydrogen atom or an alkyl group having 5 or less carbon atoms, more preferably a hydrogen atom or a methyl group.

The macromonomer according to the present invention preferably has a urea bond or thiourea bond having a 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 ₃ CSNR ₄ —.

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 reaction of isocyanate and amine or isothiocyanate and 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 used as the raw material is not particularly limited as long as it is a polyisocyanate having two or more isocyanate groups in the molecule, but is preferably an alkyl polyisocyanate or an aromatic polyisocyanate, and more preferably an alkyl diisocyanate or an aromatic diisocyanate. Further, an asymmetric diisocyanate (for example, p-isocyanate benzyl isocyanate) may be used in combination as a raw material.

Alkyl polyisocyanate is a compound in which a plurality of isocyanate groups are all present via an alkyl chain. For example, 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate Pentamethylene diisocyanate, hexamethylene diisocyanate, 1,3-cyclopentane diisocyanate, and the like.

An aromatic polyisocyanate is a compound in which a plurality of isocyanate groups are all directly bonded to an aromatic ring. For example, 9H-fluorene-2,7-diisocyanate, 9H-fluoren-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 and the like.

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, 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 polyisocyanates or polyisothiocyanates (hereinafter referred to as polyiso (thio) cyanates) and used as macromonomer raw materials. It may be used as an extender.

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. The urethane bond can be obtained by a reaction between a hydroxyl group and an isocyanate group, and examples of the compound having a hydroxyl group include polyols, amino alcohols, aminophenols, and alkylaminophenols. A polyol or an amino alcohol is preferable, and an amino alcohol is more preferable.

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.

Amino alcohol 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, 1,3-diamino-2-propanol, and the like. These compounds having a hydroxyl group may be used as a chain extender.

The macromonomer may have an amide bond, a carbonate bond, etc. in addition to a urea bond, a thiourea bond, a urethane bond, an ester bond, and an ether bond.

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 formed at the stage of sequential synthesis. The molecular weight is a weight average molecular weight obtained by measurement by 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.

The molecular weight and molecular weight distribution can be measured according to the following methods 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) A calibration curve with 9 samples from Mw = 580 to 2,560,000 was 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 polymerize with a compound having a large dipole moment in the molecule as in the general formulas 4-6.

In order to improve the orientation of the macromonomer or polymerized resin composition, it is preferable to have at least one aromatic condensed ring structure as a partial structure of the macromonomer. Examples of the aromatic condensed ring structure include naphthalene structure, quinoline structure, anthracene structure, phenanthrene structure, pyrene structure, triphenylene structure, perylene structure, fluoranthene structure, indacene structure, acenaphthylene structure, fluorene structure, fluoren-9-one structure, Examples thereof include a carbazole structure, a tetraphenylene structure, and a structure further condensed with these structures (for example, an acridine structure, a benzoanthracene structure, a benzopyrene structure, a pentacene structure, a coronene structure, a chrysene structure, etc.).

Preferred aromatic condensed ring structures include structures of the following general formulas (ACR1) to (ASR4).

In the general formula (ACR1), R ₁₁ and R ₁₂ each independently represent a hydrogen atom or a substituent. Examples of the substituent include an alkyl group having 1 to 25 carbon atoms (methyl group, ethyl group, propyl group, Isopropyl group, tert-butyl group, pentyl group, hexyl group, cyclohexyl group etc., cycloalkyl group (cyclohexyl group, cyclopentyl group etc.), aryl group (phenyl group etc.), heterocyclic group (pyridyl group, thiazolyl group, oxazolyl) Group, imidazolyl group, furyl group, pyrrolyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, selenazolyl group, sriphoranyl group, piperidinyl group, pyrazolyl group, tetrazolyl group, etc.), alkoxy group (methoxy group, ethoxy group, propyloxy group, Pentyloxy group, cyclopentyloxy group, hexyloxy group, Chlorooxy group), aryloxy group (phenoxy group, etc.), acyloxy group (acetyloxy group, propionyloxy group, etc.), alkoxycarbonyl group (methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, etc.), Aryloxycarbonyl group (phenyloxycarbonyl group, etc.), sulfonamide group (methanesulfonamide group, ethanesulfonamide group, butanesulfonamide group, hexanesulfonamide group, cyclohexanesulfonamide group, benzenesulfonamide group, etc.), carbamoyl group (Aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, phenylaminocarbonyl Group, 2-pyridylaminocarbonyl group), a carboxyl group, and a hydroxyl group. A hydrogen atom, a hydroxyl group, a carboxyl group, an alkoxy group, an acyloxy group or an alkyl group is preferred, a hydrogen atom, an alkyl group, a hydroxyl group or an acyloxy group is more preferred, and a hydrogen atom or an alkyl group is particularly preferred. is there.

Note that an asterisk (*) represents a connection point.

In the general formula (ACR2), X ₂ represents an oxygen atom, N—R ₂₃ , or C—R ₂₄ , and R ₂₃ represents a hydrogen atom, a hydroxyl group, an alkoxy group, an alkyl group, or an amino group, preferably A hydroxyl group or an alkoxy group; R ₂₄ represents an alkyl group, an aryl group, or a heterocyclic group, preferably an alkyl group or an aryl group, and particularly preferably an alkyl group.

Note that an asterisk (*) represents a connection point.

In the general formula (ACR3), X ₃ represents a nitrogen atom or N ⁺ —R ₃₃ , and R ₃₃ represents an alkyl group or an aryl group. When X ₃ is N ⁺ , it may have a counter ion for neutralizing the charge, and examples of the counter ion include Cl ⁻ , Br ⁻ , I ⁻ and BF ₄ ⁻ .

Note that an asterisk (*) represents a connection point.

In the general formula (ACR4), an asterisk (*) represents a bonding point.

These aromatic condensed ring structures may have a substituent. Examples of the substituent include a halogen atom, an alkyl group having 1 to 25 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group). Group, pentyl group, hexyl group, cyclohexyl group, etc.), halogenated alkyl group (trifluoromethyl group, perfluorooctyl group, etc.), cycloalkyl group (cyclohexyl group, cyclopentyl group, etc.), alkynyl group (propargyl group, etc.), Glycidyl group, acrylate group, methacrylate group, aryl group (phenyl group, etc.), heterocyclic group (pyridyl group, thiazolyl group, oxazolyl group, imidazolyl group, furyl group, pyrrolyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, selenazolyl group , Sriphoranyl group, Piperidinyl group, Pyrazolyl group, Tetra Ryl group), halogen atom (chlorine atom, bromine atom, iodine atom, fluorine atom, etc.), alkoxy group (methoxy group, ethoxy group, propyloxy group, pentyloxy group, cyclopentyloxy group, hexyloxy group, cyclohexyloxy group) ), Aryloxy groups (phenoxy group, etc.), alkoxycarbonyl groups (methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, etc.), aryloxycarbonyl groups (phenyloxycarbonyl group, etc.), sulfonamide groups (methane) Sulfonamide group, ethanesulfonamide group, butanesulfonamide group, hexanesulfonamide group, cyclohexanesulfonamide group, benzenesulfonamide group, etc.), sulfamoyl group (aminosulfonyl group, methylaminosulfonyl group, di Tilaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, phenylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), urethane group (methylureido group, ethylureido group, pentylureido group, cyclohexylureido) Group, phenylureido group, 2-pyridylureido group, etc.), acyl group (acetyl group, propionyl group, butanoyl group, hexanoyl group, cyclohexanoyl group, benzoyl group, pyridinoyl group, etc.), carbamoyl group (aminocarbonyl group, methyl group) Aminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, phenylaminocarbonyl group, 2-pyridylami Nocarbonyl group), amide group (acetamide group, propionamide group, butanamide group, hexaneamide group, benzamide group, etc.), sulfonyl group (methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, phenylsulfonyl group) 2-pyridylsulfonyl group, etc.), amino group (amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, anilino group, 2-pyridylamino group, etc.), cyano group, carboxyl group, hydroxyl group, etc. Can be mentioned. These groups may be further substituted with these groups. When there are a plurality of substituents, they may be the same or different, and may be bonded to each other to form a condensed ring structure. Preferred is a hydrogen atom, halogen atom, amide group, alkyl group or aryl group, more preferred is a hydrogen atom, halogen atom, amide group or alkyl group, and particularly preferred is a hydrogen atom, halogen atom or alkyl group. is there.

The following are examples of preferred aromatic condensed ring structures, but the present invention is not limited thereto.

《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.

Examples of the compound having active hydrogen include urea compounds substituted with an alkyl group having a hydroxyl group or an amino group at the terminal, polyamines, polyols, amino alcohols, aminophenols, alkylaminophenols, etc. mentioned above. 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 polyiso (thio) cyanate having an aromatic condensed ring structure. A compound having an active hydrogen at the terminal may be synthesized by condensing with a compound having an active hydrogen, or a diamine may be formed by the method described in JP-A No. 5-115842.

In addition, a macromonomer having a vinyl group, an acryloyl group or a methacryloyl group at a terminal by reacting a macromonomer having an active hydrogen at a terminal with 3-chloro-1-butene, allyl chloride, acryloyl chloride, methacryloyl chloride or the like. 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 moles, more preferably 1 to 3 moles.

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 moles, more preferably 1 to 3 moles.

The reaction temperature for condensation is preferably as low as possible, and is −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 in the reaction, it is necessary to use a highly polar solvent in order that the target resin composition has a high polarity 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.

In order to efficiently promote urethane bond formation, tertiary alkylamines such as N, N, N ′, N′-tetramethyl-1,3-butanediamine, triethylamine, tributylamine, 1,4-diazabicyclo [2. 2.2] Known urethane bond formation catalysts such as condensed ring amines such as octane and 1,8-diazabicyclo [5.4.0] unde-7-ene, and alkyltins such as DBTL, tetrabutyltin and tributyltin acetate Can be used.

The amount of 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 when forming a compound having an active hydrogen at the terminal.

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.

The “good solvent” referred to here 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 the macromonomer will be given below, but the present invention is not limited to this.

<Synthesis example of macromonomer>
[Synthesis Example 1: 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 concentration under reduced pressure, 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. It was confirmed by 1H-NMR that it was the target product.

[Synthesis Example 2: 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 thoroughly dried to obtain 1,1 ′-(9H-fluorene-2,7-diyl) bis (3- (3-amino-2,2-dimethylpropyl) urea. )

In 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. 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 was slowly added dropwise, and after completion of the addition 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. The supernatant was removed with decant and then dried under reduced pressure to obtain 6.5 g of macromonomer (M-15). The weight average molecular weight by GPC measurement was 810, and molecular weight distribution was 1.6.

[Synthesis Example 3: Synthesis of Macromonomer (M-31)]
Under a 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. To the residue was added a mixed solution of ethyl acetate-heptane and stirred. The supernatant was removed with decant, 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 4: Synthesis of Macromonomer (M-35)]
Under a 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 was slowly added dropwise at room temperature. After completion of dropping, the mixture was stirred at room temperature for 3 hours. The residue was concentrated and recrystallized to obtain 9.2 g of macromonomer (M-35). It was confirmed by 1H-NMR that it was 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 mainly composed of vinylidene fluoride can be used from the viewpoints of good piezoelectric characteristics, availability, and the like.

Specifically, 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 is preferable.

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

For example, in the case of vinylidene fluoride / trifluoroethylene 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 preferably 70 to 95 mol%.

A polymer containing 70 to 95 mol% of vinylidene fluoride and 5 to 30 mol% of perfluoroalkyl vinyl ether, perfluoroalkoxyethylene, perfluorohexaethylene or the like is used for 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 above-mentioned polymeric piezoelectric material is characterized in that it can be made into a vibrator that can be used for transmission and reception of higher frequencies because it can be made thinner than inorganic piezoelectric materials made of ceramics.

"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.

(Method for producing organic piezoelectric material)
The organic piezoelectric material of the present invention can be produced by using various methods known in the art, but it is possible to cast the layer containing fine particles according to the present invention so as to be in direct contact with the casting support. Our study revealed that this is preferable. Hereafter, the method by this casting is demonstrated.

(Manufacturing process)
The manufacturing method of the organic piezoelectric material of the present invention will be described with reference to the process diagram shown in FIG.

FIG. 1 is a process diagram showing an example of an organic piezoelectric material manufacturing apparatus of the present invention. Organic Piezoelectric Material An organic piezoelectric material liquid tank 1 for preparing an organic piezoelectric material liquid is charged with an organic piezoelectric material liquid 1a, and a fine particle additive liquid tank 2 is charged with a fine particle additive liquid 2a. The organic piezoelectric material liquid 1a is sent to the in-

line mixers

5a and 5b by the liquid feed pumps 4b and 4c, and the fine particle additive liquid 2a is sent to the in-line mixer 5a by the pump 4a. The organic piezoelectric material liquid 1 a and the fine particle additive liquid 2 a are sufficiently mixed by the in-line mixer 5 a and sent to the slit of the slit die 6.

Similarly, the organic piezoelectric material liquid 1 a and the additive liquid 3 a are sufficiently mixed by the in-line mixer 5 b and sent to the slit of the slit die 6. The upper and lower surface layers from the slit die 6 are composed of a mixed liquid of the organic piezoelectric material liquid 1a and the fine particle additive liquid 2a, and the middle layer is cast in a mixed liquid state of the organic piezoelectric material liquid 1a and the additive liquid 3a. It is cast on the casting belt 8 which is cast from the mouth and continuously moves from the drum 7. The three layers of the organic piezoelectric material liquid layer thus cast are dried, and then peeled off from the casting belt by the roller 9 as a laminated film 10 of the organic piezoelectric material.

Hereinafter, the co-casting method according to the method for producing the organic piezoelectric material of the present invention will be described in more detail.

“Co-casting” is a sequential multi-layer casting method in which two or three layers are configured through different dies, and simultaneous multi-layer flow in a die having two or three slits to form a two or three layers. Any of a casting method and a multilayer casting method in which sequential multilayer casting and simultaneous multilayer casting are combined may be used.

In the present invention, the “liquid in which the organic piezoelectric material is dissolved” is a state in which the organic piezoelectric material is dissolved in a solvent (solvent). The organic piezoelectric material liquid includes a hardener, a plasticizer, Additives such as antioxidants may be added and, of course, other additives may be added as necessary. The solid concentration in the organic piezoelectric material liquid is preferably 5 to 30% by mass, more preferably 10 to 25% by mass.

The solvent used in the present invention may be used alone or in combination, but it is preferable to use a mixture of a good solvent and a poor solvent from the viewpoint of production efficiency, and more preferably, the mixing ratio of the good solvent and the poor solvent is good. The solvent is 70 to 99% by mass, and the poor solvent is 30 to 1% by mass. The “good solvent” and “poor solvent” used in the present invention are defined as those that dissolve the organic piezoelectric material used alone as good solvents and those that swell or do not dissolve alone as poor solvents.

Therefore, good and poor solvents vary depending on the type and structure of the organic piezoelectric material. For example, when methyl ethyl ketone is used as a solvent, it becomes a good solvent for PVDF and the like, and is a diisocyanate compound such as 4,4′-diphenylmethane diisocyanate (MDI). And a polyurea resin composed of a diamine compound such as 4,4′-diaminodiphenylmethane (MDA) is a poor solvent.

Examples of the good solvent used in the present invention include a solvent such as methyl ethyl ketone, dimethylformamide, dimethylacetamide, dimethylformamide, N-methylpyrrolidone, and the like.

As the poor solvent used in the present invention, for example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone, etc. are preferably used.

As a method for dissolving the organic piezoelectric material when preparing the organic piezoelectric material liquid, a general method can be used. However, as a preferable method, the organic piezoelectric material is mixed with a poor solvent, wetted or swollen, Further, a method of mixing with a good solvent is preferably used. At this time, in order to prevent the generation of massive undissolved material called gel or mamako, heating and stirring at a temperature above the boiling point of the solvent at room temperature under pressure and dissolving while stirring It may be used. The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or by increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

The heating temperature with the addition of the solvent is preferably a temperature that is not lower than the boiling point of the solvent used and does not boil, and is preferably set in the range of 40 ° C. or higher and 50 to 100 ° C., for example. The pressure is adjusted at a set temperature so that the solvent does not boil.

After dissolution, remove from the container while cooling, or extract from the container with a pump, etc. and cool with a heat exchanger etc., and use this for film formation. The cooling temperature at this time may be cooled to room temperature, but it is more preferable to cool to a temperature 5 to 10 ° C. lower than the boiling point and perform casting at that temperature because the viscosity of the organic piezoelectric material liquid can be reduced.

For example, in the production of an organic piezoelectric material having two or more layers according to the present invention, an organic piezoelectric material solution in which an organic piezoelectric material is dissolved in a solvent and a solution in which fine particles and a small amount of the organic piezoelectric material are dissolved are mixed with an in-line mixer. Organic piezoelectric material liquid A prepared by mixing and dispersing and organic piezoelectric material liquid B in which the organic piezoelectric material is dissolved (other additives such as a crosslinking agent are added separately in-line as necessary). And using the die slit having a plurality of slits, the organic piezoelectric material liquid A containing fine particles is directly cast on the casting belt so as to be co-cast (casting process), and then , After removing a part of the solvent by heating (drying process on the casting belt), peeling from the casting belt, and drying the peeled film (film drying process), the two or more layers of the present invention Organic piezoelectric material is obtained It is.

As the support in the casting process, a support in which a belt-like or drum-like stainless steel is mirror-finished is preferably used. The temperature of the support in the casting process can be cast in a general temperature range of 0 ° C. to a temperature lower than the boiling point of the solvent, but the dope is gelled by casting on a support at 0 to 60 ° C. In order to increase the peeling limit time, it is preferable to cast it on a support at 5 to 40 ° C. The peeling limit time is the time during which the cast organic piezoelectric material liquid is on the support at the limit of the casting speed at which a transparent and flat film can be continuously obtained. A shorter peeling limit time is preferable because of excellent productivity.

The surface temperature of the support on the side to be cast (cast) is 10 to 80 ° C., the temperature of the solution is 15 to 60 ° C., and the temperature of the solution is preferably higher than the temperature of the support by 0 ° C. or more. More preferably, it is set to 5 ° C. or higher. The higher the solution temperature and the support temperature, the faster the solvent can be dried. However, if the temperature is too high, foaming or flatness may be deteriorated.

A more preferable range of the temperature of the support is 20 to 40 ° C., and a more preferable range of the solution temperature is 35 to 45 ° C. Further, it is preferable that the temperature of the support at the time of peeling is 10 to 40 ° C., more preferably 15 to 30 ° C., because the adhesion between the organic piezoelectric material and the support can be reduced. In order for the organic piezoelectric material during production to exhibit good flatness, the residual solvent amount when peeling from the support is preferably 10 to 80%, more preferably 20 to 40% or 60 to 80%. And particularly preferably 20 to 30%.

In the present application, the amount of residual solvent is defined by the following formula.

Residual solvent amount = (mass before heat treatment−mass after heat treatment) / (mass after heat treatment) × 100%
Note that the heat treatment for measuring the residual solvent amount means that the organic piezoelectric material is heat-treated at a temperature of 100 to 200 ° C. for 1 hour.

Peeling is usually performed at a peeling tension of 20 to 25 kg / m when peeling the support from the organic piezoelectric material. However, the organic piezoelectric material of the present invention, which is a thin film, is prone to wrinkles during peeling. Peeling with a minimum tension of ˜17 kg / m is preferable, and peeling with a minimum tension of ˜14 kg / m is more preferable. In the drying process of the organic piezoelectric material, the organic piezoelectric material peeled off from the support is further dried, and the residual solvent amount is preferably 3% by mass or less, more preferably 0.1% by mass or less. .

In the drying process, generally, a method of drying while transporting the organic piezoelectric material by a roll suspension method or a pin tenter method is adopted. As an organic piezoelectric material, it is preferable to dry while maintaining the width by a pin tenter method in order to improve dimensional stability. In particular, it is particularly preferable to maintain the width in a large amount of residual solvent immediately after peeling from the support because the effect of improving dimensional stability is more exhibited. The means for drying is not particularly limited, and is generally performed with hot air, infrared rays, a heating roll, microwaves, or the like. It is preferable to carry out with hot air in terms of simplicity. The drying temperature is preferably in the range of 30 to 200 ° C. and gradually increased to 3 to 5 stages, and more preferably in the range of 50 to 140 ° C. in order to improve dimensional stability.

(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.

The specific method and conditions of the solution polymerization coating method can be performed 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.

As the stretching film forming method, various known methods can be employed. 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, this 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 apparatus comprising a high voltage power source and electrodes.

As the electrodes, needle-like electrodes, linear electrodes (wire electrodes), and mesh electrodes 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”.

Note that the definition of mass absolute humidity under a nitrogen or rare gas (helium, argon, etc.) stream is the same as that of the above air, and the moisture vapor contained in the moist gas with respect to the mass m _DG [kg] of the dry gas. When the mass is m _w [kg], the ratio SH is 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 appropriately. However, the voltage of the high voltage power supply is 1 to 20 kV for both positive and negative voltages, the current is 1 to 80 mA, and the distance between the electrodes is as follows. 0.5-10 cm, and the applied electric field is preferably 0.5-2.0 MV / m. The organic piezoelectric material or 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 cylindrical electrode as described above in order to perform polarization treatment uniformly.

In the present application, the diameter of the circle of the cylindrical electrode is preferably 0.1 mm to 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 with a constant load. Moreover, as a constituent material of these electrodes, a general metal material can be used, but gold, silver and copper are particularly preferable.

It is preferable that the planar electrode installed so as to be in contact with the first surface is in close contact with the organic piezoelectric material in order to perform a uniform polarization process. 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 performed either after an electrode formation only on one side or after 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.

(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. Alternatively, a single crystal plate or film of aluminum, gold, copper, magnesium, silicon alone, or a rare earth halide may 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 converge 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 receiving vibrator and the ultrasonic transmitting vibrator 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 3 to 50 at the thickness resonance frequency. The adjustment of the relative dielectric constant is carried out by adjusting the number, composition, polymerization degree, 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.

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

In the following examples, the numerical value in parentheses indicates 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), vinegar Vinyl 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.

As the ultrasonic transmission vibrator constituting material, various known organic piezoelectric materials and inorganic piezoelectric materials can be used.

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 niobate tantalate [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 mainly composed of gold (Au), platinum (Pt), silver (Ag), palladium (Pd), copper (Cu), nickel (Ni), tin (Sn), aluminum (Al), etc. It forms using.

In forming the electrode, 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 element and the above A metal material made of the above alloy, and further, if necessary, a part of 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 a fine metal powder and low-melting glass are mixed.

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

(Ultrasonic probe)
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 the transmission and reception of ultrasonic waves may be performed by a single transducer, but more preferably, the transducer is 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. In view of a practical ultrasonic medical image diagnostic 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.

(Ultrasonic medical diagnostic imaging equipment)
The ultrasonic probe according to the present invention can be used for various types of ultrasonic diagnostic apparatuses. For example, it can be suitably used in an ultrasonic medical image diagnostic apparatus as shown in FIGS.

FIG. 2 is a conceptual diagram showing a configuration of a main part of the ultrasonic medical image diagnostic apparatus according to the 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 for converting the echo signal 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.

The transmission / reception control circuit, the image data conversion circuit, and the display control circuit are connected to the control circuit, and the control circuit controls the 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 electric 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 wave 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.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1
(Preparation of organic piezoelectric material 1)
A 0.5 L four-necked separable flask was equipped with a dropping device, a thermometer, a nitrogen gas introduction tube, a stirring device, and a reflux condenser, and dehydrated with 25.0 g of 4,4′-diphenylmethane diisocyanate as a monomer at 0 ° C. 100 g of tetrahydrofuran was added and dissolved (ground). Further, 19.8 g of 2,7-diaminofluorene and 100 g of dehydrated tetrahydrofuran at 0 ° C. were mixed and dissolved, and dropped into the ground at a rate of 2 g / min in an ice bath, followed by stirring for 1 hour. Thereafter, the residue was collected by filtration and washed with acetone adjusted to 0 ° C. The filter cake was dried under reduced pressure to obtain 40.2 g of organic piezoelectric material 1. Other organic piezoelectric materials 2 to 3 were produced in the same manner as the organic piezoelectric material 1 using the materials shown in Table 1.

(Preparation of organic piezoelectric material 4)
A 0.5 L four-necked separable flask is equipped with a dropping device, a thermometer, a nitrogen gas introduction tube, a stirring device, and a reflux condenser. Furthermore, 40 g of p-trifluoromethylstyrene is used as a monomer, and azobisiso is used as an initiator. 164 mg (1 mmol) of butyronitrile (AIBN) and 360 g of degassed methanol as a solvent were added and mixed. The mixture was gradually heated and stirred at 65 ° C. for 8 hours. Thereafter, the mixture was cooled to 0 ° C., and the resulting precipitate was collected by filtration and washed with methanol at 0 ° C. The filtrate was dried under reduced pressure to obtain 32 g of polymer 1 (poly (p-trifluoromethylstyrene)).

(Preparation of surface-treated fine particle dispersion 1)
After adding 50 g of Pb (Zr, Ti) O ₃ fine particles (sintered body) powder whose primary particles have a mass average diameter of 50 nm to 450 g of butyl acetate heated at 80 ° C., and stirring and mixing with a dissolver for 30 minutes, Dispersion was performed with Menton Gorin. Thereafter, 4.5 g of N-phenyl-γ-aminopropyltrimethoxysilane was added dropwise at a rate of 0.5 g / min with stirring and reacted for 60 minutes. After the reaction, the solvent was distilled off, 350 g of dimethylformamide was added, the mixture was again stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin to prepare surface-treated fine particle dispersion 1. The other surface-treated fine particle dispersions 2 to 9 were prepared in the same manner as the surface-treated fine particle dispersion 1 with the surface treatment agents shown in Table 2.

(Preparation of organic piezoelectric material solution 1)
After adding 420 g of dimethylformamide to 100 g of polyvinylidene fluoride (PVDF), stirring and dissolving completely, 80 g of the surface-treated fine particle dispersion 1 was added dropwise at a rate of 10 g / min, and stirring and mixing for 30 minutes with a dissolver An organic piezoelectric material solution 1 was prepared. Other organic piezoelectric material solutions 2 to 9 were organic piezoelectric materials shown in Table 2 and were prepared in the same manner as the organic piezoelectric material solution 1.

(Preparation of organic piezoelectric film 1)
The organic piezoelectric material solution 1 was filtered, and then uniformly cast using a belt casting apparatus. On the stainless steel casting belt, the solvent was evaporated until the residual solvent amount was 25%, and it was peeled off from the casting belt with a peeling tension of 13 kg / m. The peeled organic piezoelectric material was slit to a width of 700 mm, and then dried while being transported by a roll through a roll, and then slit to a width of 500 mm to produce an organic piezoelectric film 1. Other organic piezoelectric films 2 to 9 were produced in the same manner as the organic piezoelectric film 1 under the conditions shown in Table 2.

(Preparation of Comparative Film 1)
500 g of dimethylformamide was added to 100 g of polyvinylidene fluoride, stirred and completely dissolved, and then formed in the same manner as in (Preparation of Organic Piezoelectric Film 1) to prepare Comparative Film 1.

(Preparation of Comparative Film 2)
50 g of Pb (Zr, Ti) O ₃ fine particle powder having a primary particle mass average diameter of 50 nm is added to 350 g of butyl acetate adjusted at 80 ° C., and stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. The fine particle dispersion 1 was prepared. Next, after adding 420 g of dimethylformamide to 100 g of polyvinylidene fluoride, stirring and completely dissolving, 80 g of the fine particle dispersion 1 was dropped at a rate of 10 g / min, and stirring and mixing with a dissolver for 30 minutes. A comparative organic piezoelectric material solution 1 was prepared. Thereafter, a film was formed in the same manner as in (Preparation of organic piezoelectric film 1), and Comparative film 2 was prepared. The other comparative films 3 to 7 were also formed in the same manner as the comparative film 2 under the conditions shown in Table 2.

(Measurement of dynamic friction coefficient)
The dynamic friction coefficient (μ) between the organic piezoelectric film surface and the back surface is cut out so that the front and back surfaces of the film are in contact with each other according to JIS-K-7125 (1987), a 200 g weight is placed, the sample moving speed is 100 mm / min, The weight was pulled horizontally under the condition of a contact area of 80 mm × 200 mm, and the average load (F) while the weight was moving was measured and determined from the following formula.

Coefficient of dynamic friction = F (gf) / weight of weight (gf)
The results are shown in Table 2. From the results shown in Table 2, it can be seen that the use of the means of the present invention improves the slipperiness of the film when producing a large-area organic piezoelectric film, thereby improving the scratch resistance of the organic piezoelectric film. .

Example 2
(Preparation of ultrasonic transducer 1)
The organic piezoelectric film 1 produced in Example 1 was stretched four times at room temperature according to the conditions described in Table 2, and then heated to 135 ° C. at a rate of 5 ° C./min while maintaining the stretched length. After stagnation for 5 minutes, it was naturally cooled to 25 ° C. Thereafter, aluminum electrodes are applied to both surfaces of the obtained film by vapor deposition, and corona discharge polarization is performed at an electric field of 2.0 MV / m using a high voltage power supply HARb-20R60 (manufactured by Matsusada Precision Co., Ltd.) and needle electrodes. The ultrasonic transducer using the organic piezoelectric film 1 was manufactured by performing the treatment. Similarly, for the organic piezoelectric films 2 and 5, ultrasonic vibrators 2 and 5 were produced.

(Preparation of ultrasonic transducer 3)
The organic piezoelectric material solution 3 produced in Example 1 was filtered, and then uniformly cast using a belt casting apparatus. On the stainless steel casting belt, the solvent was evaporated until the residual solvent amount was 25%, and it was peeled off from the casting belt with a peeling tension of 13 kg / m. One side of the obtained film was provided with an aluminum electrode by vapor deposition, heated to 180 ° C. at a rate of 5 ° C./min, stagnated for 5 minutes, then naturally cooled to 25 ° C. Meanwhile, ultrasonic vibration using the organic piezoelectric material solution 3 was performed using a high voltage power supply device HARb-20R60 (manufactured by Matsusada Precision Co., Ltd.) and needle electrodes, and performing corona discharge polarization treatment with an electric field of 2.0 MV / m. Child 3 was produced. Similarly, for the organic piezoelectric material solutions 4, 5, 6, 7, and 8, ultrasonic vibrators 4, 5, 6, 7, 8, and 9 were produced.

(Production of comparative ultrasonic transducer 1)
Using the comparative film 1 produced in Example 1, the production of the comparative ultrasonic vibrator 1 was produced in the same manner as in the (Production of ultrasonic vibrator 1) method. The comparison ultrasonic transducers 2 and 4 were similarly manufactured, and the comparison ultrasonic transducers 2 and 4 were manufactured.

(Preparation of comparative ultrasonic transducer 3)
Using the comparative organic piezoelectric material 1 produced in Example 1, a comparative ultrasonic vibrator 3 was produced in the same manner as in (Production of ultrasonic vibrator 3). The comparative ultrasonic transducers 5 to 7 were similarly manufactured, and comparative ultrasonic transducers 5 to 7 were manufactured.

<< Evaluation of the produced ultrasonic transducer >>
Evaluations of the obtained ultrasonic transducers 1 to 10 and comparative ultrasonic transducers 1 to 7 are based on a multifunction AFM (manufactured by PACIFIC NANOTECHNOLOGY) equipped with a Nano-R2 / I2 closed loop linear scanner and FCE-1 type ferroelectrics Piezoelectricity was measured with a body property evaluation system (manufactured by Toyo Technica).

The evaluation results are shown in Table 2.

As is clear from the results shown in Table 2, it can be seen that in the examples according to the present invention, the piezoelectricity is superior to the comparative example.

Example 3
(Fabrication and evaluation of the 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 _.03 . ) Bi ₄ . ₀₁
Weighed to be 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 the fine 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 1 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 receiving transducer 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 reception sensitivity and dielectric breakdown strength.

As for the reception sensitivity, a fundamental frequency f _{1 of} 5 MHz was transmitted, and a reception relative sensitivity of 10 MHz as the reception second harmonic f ₂ , 15 MHz as the third harmonic, and 20 MHz as the fourth harmonic was obtained. For the relative sensitivity of reception, a sound intensity measurement system Model 805 (1 to 50 MHz) of Sonora Medical System, Inc. (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 standard to evaluate the relative reception sensitivity. The sensitivity was evaluated as good when the decrease in sensitivity was within 1% before the load test.

In the above evaluation, the probe including 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 the dielectric breakdown strength is It was confirmed to be 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.

Claims

An organic piezoelectric material comprising inorganic metal oxide fine particles surface-treated with an organic surface treatment agent.
2. The organic piezoelectric material according to claim 1, wherein the organic surface treating agent has at least one of an alkyl group or an aryl group having 2 to 20 carbon atoms.
3. The organic piezoelectric material according to claim 1, wherein the inorganic metal oxide fine particles are fine particles containing an inorganic piezoelectric material.
The inorganic metal oxide fine particle is a fine particle containing a sintered body of quartz, LiNbO 3 , LiTaO 3 , KNbO 3 single crystal, ZnO, or Pb (Zr, Ti) O 3 . The organic piezoelectric material according to item 3 in the range.
The organic piezoelectric material is formed of a polymer material having a urea structure or a thiourea structure, or a composite material containing the polymer material having a urea structure or a thiourea structure. The organic piezoelectric material according to claim 4.
The organic piezoelectric material 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. The organic piezoelectric material according to claim 5.
An organic piezoelectric film using the organic piezoelectric material according to any one of claims 1 to 6.
An ultrasonic transducer using the organic piezoelectric material according to any one of claims 1 to 6 as an organic piezoelectric film.
An ultrasonic probe including an ultrasonic transmission transducer and an ultrasonic reception transducer, which is formed using the organic piezoelectric material according to any one of claims 1 to 6. An ultrasonic probe using the ultrasonic transducer made as an ultrasonic receiving transducer.
Ultrasound in which a means for generating an electrical signal and a plurality of transducers for receiving the electrical signal and transmitting an ultrasonic wave toward the subject and generating a reception signal corresponding to the reflected wave received from the subject are arranged In the ultrasonic medical image diagnostic apparatus, comprising: an ultrasonic probe; and an image processing unit that generates an image of the subject according to the reception signal generated by the ultrasonic probe. An ultrasonic medical diagnostic imaging apparatus using an ultrasonic probe formed using the organic piezoelectric material according to any one of claims 1 to 6.