阅读说明：本技术 声匹配片、声匹配层用组合物、声波探头、声波测定装置及声波探头的制造方法 (Acoustic matching sheet, composition for acoustic matching layer, acoustic wave probe, acoustic wave measurement device, and method for manufacturing acoustic wave probe ) 是由 滨田和博 中井义博 于 2020-03-19 设计创作，主要内容包括：一种在下述成分(A)中含有下述成分(B)的声匹配片、声匹配层用组合物、声波探头、声波测定装置及声波探头的制造方法。其中,(A)：树脂及橡胶中的至少一种,(B)：树脂粒子及橡胶粒子中的至少一种,其具有比上述成分(A)低的声速,数均粒径为1.0μm以下。(An acoustic matching sheet containing the following component (B) in the following component (A), a composition for an acoustic matching layer, an acoustic wave probe, an acoustic wave measuring apparatus, and a method for manufacturing an acoustic wave probe. Wherein (A): at least one of a resin and a rubber, (B): at least one of resin particles and rubber particles having a lower sound velocity than the component (A) and a number average particle diameter of 1.0 μm or less.)

1. An acoustic matching sheet comprising the following component (B) in the following component (A),

component (A): at least one of a resin and a rubber,

component (B): at least one of resin particles and rubber particles, wherein the component (B) has a lower sound velocity than the component (A), and the number average particle diameter of the component (B) is 1.0 [ mu ] m or less.

2. The acoustic matching patch of claim 1,

the number average particle diameter of the component (B) is 0.5 [ mu ] m or less.

3. The acoustic matching patch of claim 2,

the number average particle diameter of the component (B) is 0.2 [ mu ] m or less.

4. The acoustic matching sheet according to any one of claims 1 to 3,

the component (A) is at least one of an epoxy resin and a polyamide resin.

5. The acoustic matching patch of claim 4,

the component (A) is an epoxy resin.

6. The acoustic matching patch of claim 5,

the component (A) is at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin and phenol novolac type epoxy resin.

7. The acoustic matching sheet according to any one of claims 1 to 6,

the component (B) is at least one of acrylic resin particles, silicone resin particles and rubber particles.

8. The acoustic matching patch of claim 7,

the component (B) is at least one of silicone resin particles and rubber particles.

9. The acoustic matching patch of claim 8,

the component (B) is rubber particles.

10. The acoustic matching sheet according to any one of claims 1 to 9, containing (C): metal particles.

11. The acoustic matching patch of claim 10,

the metal element constituting the component (C) contains at least one of metal elements of groups 4 to 13.

12. The acoustic matching patch of claim 11,

the metal element constituting the component (C) contains at least one of Zn, In, Au, Ag, Co, Zr, W, Ta, Fe, Cu, Ni, Nb, Pt, Mn and Mo.

13. A composition for acoustic matching layers comprising components (A1) and (B1),

component (a 1): at least one of a resin and a rubber,

component (B1): at least one of resin particles and rubber particles, wherein the component (B1) has a lower sound velocity than the component (A1), and the number average particle diameter of the component (B1) is 1.0 [ mu ] m or less.

14. An acoustic wave probe having the acoustic matching sheet according to any one of claims 1 to 12 in an acoustic matching layer.

15. An acoustic wave measurement device comprising the acoustic wave probe according to claim 14.

16. The acoustic wave measurement apparatus according to claim 15,

the acoustic wave measurement device is an ultrasonic diagnostic device.

17. A method of manufacturing an acoustic wave probe, comprising:

a process for forming an acoustic matching layer using the composition for an acoustic matching layer according to claim 13.

Technical Field

The present invention relates to an acoustic matching sheet, a composition for an acoustic matching layer, an acoustic wave probe, an acoustic wave measurement device, and a method for manufacturing an acoustic wave probe.

Background

An acoustic wave measurement device uses an acoustic wave probe that irradiates an acoustic wave to a subject such as a living body, receives a reflected wave (echo) of the acoustic wave, and outputs a signal. The reflected waves received by the acoustic wave probe are converted into electrical signals and displayed as an image. Therefore, by using the acoustic probe, the inside of the subject can be visualized and observed.

As the acoustic wave, an ultrasonic wave, a photoacoustic wave, or the like is appropriately selected depending on the subject to be examined or depending on the measurement conditions.

For example, an ultrasonic diagnostic apparatus, which is one type of acoustic wave measurement apparatus, transmits ultrasonic waves into an object to be examined, receives ultrasonic waves reflected by tissues inside the object to be examined, and displays the ultrasonic waves as an image.

The photoacoustic wave measurement device receives an acoustic wave radiated from the inside of the subject by the photoacoustic effect and displays the acoustic wave as an image. The photoacoustic effect is a phenomenon in which when an electromagnetic wave pulse such as visible light, near-infrared light, or microwave is irradiated to an object to be examined, the object to be examined absorbs the electromagnetic wave, generates heat, and thermally expands, thereby generating an acoustic wave (typically, an ultrasonic wave).

Since the acoustic wave measurement device transmits and receives an acoustic wave to and from a subject, the acoustic wave probe is required to match acoustic impedance with the subject (typically, a human body). In order to meet the requirement, an acoustic matching layer is arranged on the acoustic wave probe. This will be described by taking a probe for an ultrasonic diagnostic apparatus (also referred to as an ultrasonic probe), which is a kind of an acoustic wave probe, as an example.

The ultrasonic probe includes a piezoelectric element that transmits and receives ultrasonic waves and an acoustic lens that comes into contact with a living body, and an acoustic matching layer is disposed between the piezoelectric element and the acoustic lens. The ultrasonic waves oscillated from the piezoelectric element are transmitted through the acoustic matching layer and further transmitted through the acoustic lens to be incident on the living body. There is generally a difference in acoustic impedance (density × sound velocity) between the acoustic lens and the living body. If this difference is large, the ultrasonic wave is easily reflected on the surface of the living body, and the incidence efficiency of the ultrasonic wave into the living body is reduced. Therefore, the acoustic lens is required to have acoustic impedance characteristics close to those of the living body.

On the other hand, the difference in acoustic impedance between the piezoelectric element and the living body is generally large. Therefore, the difference in acoustic impedance between the piezoelectric element and the acoustic lens is also generally large. Therefore, when the piezoelectric element and the acoustic lens are laminated, the ultrasonic wave oscillated from the piezoelectric element is reflected on the surface of the acoustic lens, and the incidence efficiency of the ultrasonic wave to the living body is lowered. In order to suppress reflection of the ultrasonic wave, the acoustic matching layer is provided between the piezoelectric element and the acoustic lens. The acoustic impedance of the acoustic matching layer is a value between the acoustic impedance of the living body or the acoustic lens and the acoustic impedance of the piezoelectric element, whereby the propagation efficiency of the ultrasonic wave from the piezoelectric element to the living body is improved. In recent years, the following acoustic matching layers have been developed: the acoustic matching layer has a multilayer structure in which a plurality of acoustic matching sheets (acoustic matching layer materials) are laminated, and propagation of ultrasonic waves is more efficient by providing an inclination to acoustic impedance from the piezoelectric element side to the acoustic lens side.

As a material of the acoustic matching sheet constituting the acoustic matching layer having the multilayer structure, it is known to use a thermosetting resin, silicone resin particles, and the like (for example, patent document 1).

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2014-168489

Disclosure of Invention

Technical problem to be solved by the invention

The inclination of the acoustic impedance in the acoustic matching layer is designed such that the closer to the piezoelectric element, the greater the acoustic impedance of the acoustic matching sheet, and the closer to the acoustic lens, the smaller the acoustic impedance. That is, each acoustic impedance (usually 25 × 10) close to the piezoelectric element is required on the piezoelectric element side⁶kg/m²Sec or so) near the acoustic impedance of the living body on the acoustic lens side (1.4 to 1.7X 10 in the human body)⁶kg/m²Sec). In order to make the inclination more gradual, it is required to further increase the number of stacked acoustic matching pieces having different acoustic impedances.

The acoustic impedance of the acoustic matching patch can be adjusted according to the density and acoustic velocity of the constituent material of the sheet. In order to form the acoustic matching layer into a multilayer structure to set a desired tilt to the acoustic impedance, it is also necessary to prepare an acoustic matching sheet in which the acoustic velocity is suppressed.

The acoustic matching layer having a multilayer structure is generally produced by laminating acoustic matching sheets and heating the laminated acoustic matching sheets. That is, since molten solder or the like is used for fixing the electrodes to the acoustic matching layer, the acoustic matching sheet is required to have heat resistance. In addition, in order to transmit and receive ultrasonic waves (acoustic waves) with high sensitivity, the acoustic matching patch is required to have sufficient ultrasonic wave (acoustic wave) sensitivity.

However, the present inventors have conducted studies and found that it is difficult to improve both the heat resistance and the acoustic wave sensitivity to a desired level while achieving a low acoustic velocity in the acoustic matching sheet constituting the acoustic matching layer described in patent document 1.

The invention provides an acoustic matching sheet having low sound velocity, sufficient heat resistance and sufficient acoustic wave sensitivity, and a composition for an acoustic matching layer suitable for forming the sheet.

Another object of the present invention is to provide an acoustic wave probe having the acoustic matching sheet of the present invention as an acoustic matching layer, and an acoustic wave measurement apparatus using the acoustic wave probe.

Another object of the present invention is to provide a method for manufacturing an acoustic wave probe, which includes a step of forming an acoustic matching layer using the composition for forming the acoustic matching sheet of the present invention.

Means for solving the technical problem

As a result of intensive studies in view of the above-described problems, the present inventors have found that a sheet comprising at least one of a resin and a rubber as a base material and at least one of resin particles and rubber particles having a lower sound velocity than the base material and a number average particle diameter of a specific value or less can reduce the sound velocity of the sheet while suppressing a decrease in heat resistance and sound wave sensitivity due to the inclusion of the particles. The present invention has been completed by further and repeated studies based on this finding.

That is, the above object of the present invention is achieved by the following method.

<1>

An acoustic matching sheet containing the following component (B) in the following component (A).

(A) The method comprises the following steps At least one of resin and rubber

(B) The method comprises the following steps At least one of resin particles and rubber particles having a lower sound velocity than the component (A) and a number average particle diameter of 1.0 [ mu ] m or less

<2>

The acoustic matching sheet according to <1>, wherein the number average particle diameter of the component (B) is 0.5 μm or less.

<3>

The acoustic matching sheet according to <2>, wherein the number average particle diameter of the component (B) is 0.2 μm or less.

<4>

The acoustic matching sheet according to any one of <1> to <3>, wherein the component (A) is at least one of an epoxy resin and a polyamide resin.

<5>

The acoustic matching sheet according to <4>, wherein the component (A) is an epoxy resin.

<6>

The acoustic matching sheet according to <5>, wherein the component (A) is at least one of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a phenol novolac type epoxy resin.

<7>

The acoustic matching sheet according to any one of <1> to <6>, wherein the component (B) is at least one of acrylic resin particles, silicone resin particles, and rubber particles.

<8>

The acoustic matching sheet according to <7>, wherein the component (B) is at least one of silicone resin particles and rubber particles.

<9>

The acoustic matching sheet according to <8>, wherein the component (B) is rubber particles.

<10>

The acoustic matching sheet according to any one of <1> to <9>, containing (C): metal particles.

<11>

The acoustic matching sheet according to <10>, wherein the metal element constituting the component (C) contains at least one of metal elements of groups 4 to 13.

<12>

The acoustic matching sheet according to <11>, wherein the metal element constituting the component (C) contains at least one of Zn, In, Au, Ag, Co, Zr, W, Ta, Fe, Cu, Ni, Nb, Pt, Mn and Mo.

<13>

A composition for acoustic matching layers comprising the components (A1) and (B1).

(A1) The method comprises the following steps At least one of resin and rubber

(B1) The method comprises the following steps At least one of resin particles and rubber particles having a lower sound velocity than the component (A1) and a number average particle diameter of 1.0 [ mu ] m or less

<14>

An acoustic wave probe having the acoustic matching sheet of any one of <1> to <12> in an acoustic matching layer.

<15>

An acoustic wave measurement device comprising the acoustic wave probe according to <14 >.

<16>

The acoustic wave measurement device according to <15>, wherein the acoustic wave measurement device is an ultrasonic diagnostic device.

<17>

A method of manufacturing an acoustic wave probe, comprising: and (3) forming an acoustic matching layer by using the composition for an acoustic matching layer described in <13 >.

In the description of the present invention, "-" is used to mean that numerical values described before and after the numerical value are included as a lower limit value and an upper limit value.

In the description of the present invention, when the number of carbon atoms of a certain group is specified, the number of carbon atoms indicates the number of carbon atoms of the whole group. That is, when the group is a form further having a substituent, the number of the total carbon atoms including the substituent is indicated.

In the description of the present invention, when a plurality of substituents, linking groups, etc. (hereinafter referred to as substituents, etc.) represented by specific symbols are present, or when a plurality of substituents, etc. are defined simultaneously or alternatively, it means that the substituents, etc. may be the same or different from each other. Further, unless otherwise specified, when a plurality of substituents and the like are adjacent to each other, they may be connected to each other or fused to form a ring.

Effects of the invention

The acoustic matching sheet of the present invention has a low acoustic velocity, sufficient heat resistance, and sufficient acoustic wave sensitivity.

The composition for an acoustic matching layer of the present invention can be formed or processed into a desired sheet shape by using the composition, and thus an acoustic matching sheet having a low sound velocity, sufficient heat resistance, and sufficient acoustic wave sensitivity can be obtained.

The acoustic wave probe and the acoustic wave measurement device using the same according to the present invention have sufficient acoustic wave sensitivity.

Further, according to the method for manufacturing an acoustic wave probe of the present invention, the acoustic wave probe of the present invention can be obtained using the composition for forming the acoustic matching sheet of the present invention.

Drawings

Fig. 1 is a perspective view of an example of a convex ultrasonic probe as one embodiment of an acoustic wave probe.

Detailed Description

[ Sound matching sheet ]

The acoustic matching sheet of the present invention (hereinafter, also simply referred to as "sheet of the present invention") contains the following component (B) in the following component (a).

(A) The method comprises the following steps At least one of resin and rubber

(B) The method comprises the following steps At least one of resin particles and rubber particles having a lower sound velocity than the component (A) and a number average particle diameter of 1.0 [ mu ] m or less

The sheet of the present invention preferably has the component (a) as a matrix, and the component (B) is dispersed in the matrix and uniformly dispersed.

In addition, in the sheet of the present invention, a tilt in acoustic impedance can be observed, and for example, in the case where a tilt in acoustic impedance is observed in any one direction of the sheet, the dispersibility (existence ratio) of the component (B) may be tilted in the above-mentioned direction.

The reason why the sheet of the present invention has the above-described structure, has low sound velocity, is excellent in heat resistance, and is excellent in acoustic wave sensitivity is not clear, but is presumed as follows.

In the component (a) as the matrix, particles of the component (B) having a lower acoustic velocity than the matrix, that is, a lower bulk modulus than the matrix are dispersed. Since the component (B) is a particle, even if the component (a) is crosslinked (cured), the crosslinking density thereof is not affected, and it is considered that the sound velocity can be reduced while suppressing the decrease in heat resistance shown by the matrix itself. Further, it is considered that, when the number average particle diameter of the particles is 1.0 μm or less, the attenuation of the acoustic wave is suppressed, and the acoustic wave sensitivity of the acoustic matching sheet can be improved in addition to the suppression of the reduction in the heat resistance and the reduction in the sound velocity.

< ingredient (A) >

The sheet of the present invention contains at least one of a resin and a rubber as the component (a). Examples of the resin include thermosetting resins and thermoplastic resins.

The component (a) is preferably at least one of a thermosetting resin and a thermoplastic resin in view of sound velocity control, and more preferably a thermosetting resin in view of a sound velocity control range.

The thermosetting resin used in the present invention is not particularly limited, and examples thereof include epoxy resin, polyurethane resin, silicone resin, phenol resin, urea resin, and melamine resin, preferably epoxy resin, polyurethane resin, silicone resin, and phenol resin, and more preferably epoxy resin.

The epoxy resin used in the present invention includes at least one of bisphenol a type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin.

The bisphenol a epoxy resin used in the present invention is not particularly limited, and resins generally used as a main agent of an epoxy adhesive can be widely used. Preferred examples thereof include bisphenol A diglycidyl ether (jER825, jER828 and jER834 (both trade names), manufactured by Mitsubishi Chemical Corporation) and bisphenol A propoxylate diglycidyl ether (manufactured by Sigma-Aldrich Co.LLC).

The bisphenol F epoxy resin used in the present invention is not particularly limited, and resins generally used as a main agent of an epoxy adhesive can be widely used. Preferred examples thereof include bisphenol F diglycidyl ether (trade name: EPICLON830, manufactured by DIC Corporation) and 4, 4' -methylenebis (N, N-diglycidylaniline).

The phenol novolac epoxy resin used in the present invention is not particularly limited, and resins generally used as a main agent of an epoxy adhesive can be widely used. This phenol novolac type epoxy resin is sold, for example, as product number 406775 by Sigma-Aldrich co.

The epoxy resin may be formed of the above epoxy resin, and other epoxy resins (for example, aliphatic epoxy resins) may be contained in addition to the above epoxy resin within a range in which the effects of the present invention are not impaired. The content of the 3 types of epoxy resins (the total content of the bisphenol a type epoxy resin, the bisphenol F type epoxy resin, and the phenol novolac type epoxy resin) in the epoxy resin is preferably 80 mass% or more, and more preferably 90 mass% or more.

In the sheet of the present invention, the thermosetting resin in the component (a) is heated and cured in the sheet production step. When the thermosetting resin is reacted with a curing agent described later and cured, the thermosetting resin may be reacted with the curing agent and cured. The same applies to the heat-curable components other than the thermosetting resin in the component (a). In the component (A), the rubber may be a crosslinked material.

That is, the predetermined component (a) in the sheet of the present invention includes a cured product of the component (a), a compound obtained by curing the component (a) with a curing agent, and a crosslinked product of the component (a). The component (a) may be bonded to the surface of the component (B).

Examples of the urethane resin include Takelac manufactured by Mitsui Chemicals, Inc., and PANDEX manufactured by Takenate, DIC Corporation (both trade names).

Examples of the Silicone resin include Shin-Etsu Silicone Co., KR220 and KR300 manufactured by Ltd., and ELASTOSIL (trade name) manufactured by wacker asahikasei Silicone co., ltd., and the like.

Examples of the phenolic resin include J-325, 5010, and 5592 (all trade names) manufactured by DIC Corporation.

Examples of the urea resin include Amidia G-1850 manufactured by DIC Corporation, Amidia P-138, Daiwa Co., FreAmine M manufactured by Ltd (trade name).

Examples of the melamine resin include Amidia L-105-60 manufactured by DIC Corporation, Freamine Z manufactured by Daiwa Co., Ltd. (trade name).

The thermoplastic resin used in the present invention is not particularly limited, and examples thereof include polyamide resins, acrylic resins, polyethylene resins, polypropylene resins, polyamideimide resins, and polyether ether ketone resins, with polyamide resins, acrylic resins, and polypropylene resins being preferred, and polyamide resins being more preferred.

Examples of the polyamide resin used in the present invention include nylon 6, nylon 66, nylon 46, nylon 610, nylon 11, nylon 12, nylon 6T, and nylon 9T.

Examples of the acrylic resin include DELPET manufactured by Asahi Kasei Corporation, Arkema co., Altglas manufactured by ltd., and ACRYPET (both trade names) manufactured by Mitsubishi Chemical Corporation.

Examples of the polyethylene resin include SUNTEC, Creolex, and SUNFINE (both trade names) manufactured by Asahi Kasei Corporation.

Examples of the polypropylene resin include Smith Tran, Sumitomo noben manufactured by Sumitomo Chemical co.

Examples of the polyamide-imide resin include TORON polyamide-imide (all trade names) manufactured by Solvay Specialty Polymers Japan K.K.

Examples of the polyether ether ketone resin include Victrex PEEK manufactured by Victrex Japan inc, and VESTAKEEP (both trade names) manufactured by Daicel-Evonik ltd.

The rubber used in the present invention is not particularly limited, and examples thereof include polyisoprene rubber, polybutadiene rubber, Ethylene Propylene Diene (EPDM) rubber, styrene butadiene rubber, ethylene propylene rubber and butyl rubber, and preferably polyisoprene rubber, polybutadiene rubber and ethylene propylene diene rubber.

The component (A) may be used alone or in combination of two or more.

< ingredient (B) >

The sheet of the present invention contains at least one of thermosetting resin particles, thermoplastic resin particles and rubber particles as a component (B), and has a lower sound velocity than the component (A) and a number average particle diameter of 1.0 μm or less.

The sound velocity of the component (B) may be lower than that of the component (A), and the difference between the sound velocity of the component (A) and the sound velocity of the component (B) ("the sound velocity of the component (A) -" the sound velocity difference of the component (B)) is preferably 50 to 1500m/s, more preferably 100 to 1000m/s, and still more preferably 400 to 1000 m/s.

The component (B) is preferably at least one of thermosetting resin particles and rubber particles from the viewpoint of sound velocity control, and more preferably rubber particles from the viewpoint of a sound velocity control range.

The sound velocity of the component (B) used in the present invention is lower than that of the component (a). The sound velocities of the component (a) and the component (B) are measured by the methods described in the examples below. The sound velocity of the component (a) when the component (a) is cured by the curing agent described later represents the sound velocity of the cured component (a). The same applies to the component (B).

The number average particle diameter of the component (B) used in the present invention is 1.0 μm or less. From the viewpoint of further improving the acoustic wave sensitivity, the number average particle diameter is preferably 0.5 μm or less, and more preferably 0.2 μm or less. The lower limit is not particularly limited, but is actually 0.01 μm or more.

The number average particle diameter is a value measured by a method described in examples described later.

The thermosetting resin particles used in the present invention are not particularly limited as long as they are thermosetting resin particles, and examples thereof include silicone resin particles, polyurethane resin particles, epoxy resin particles, and unsaturated polyester resin particles, with silicone resin particles and polyurethane resin particles being preferred, and silicone resin particles being more preferred.

Examples of the silicone resin particles include TOSPEARLs (trade name) manufactured by Momentive Performance Materials Japan LLC.

The thermoplastic resin particles used in the present invention are not particularly limited as long as they are particles of a thermoplastic resin, and examples thereof include acrylic resin particles, polyethylene resin particles, polypropylene resin particles, ABS resin particles, and polyethylene terephthalate resin particles, with acrylic resin particles, polyethylene resin particles, and polypropylene resin particles being preferred, and acrylic resin particles being more preferred.

Examples of the acrylic resin particles include Eposter (trade name) manufactured by Nippon Shokubai co.

The rubber particles used in the present invention include particles of the rubber described in the above component (a), and preferably at least one of polyisoprene rubber particles and polybutadiene rubber particles.

The component (B) may be used alone or in combination of two or more.

Among the thermosetting resin particles, those having a number average particle diameter of more than 1.0 μm can be used by wet grinding or the like so as to have a number average particle diameter of 1.0 μm or less.

The component (B) may be used alone or in combination of two or more.

Further, products containing the components (A) and (B) such as Kane Ace (registered trademark) (grades: MX-153, MX-257, MX-154, MX-960, MX-136, MX-965, MX-214, MX-227M75, MX-334M75, MX-416, and MX-451 manufactured by KANEKA CORPORATION and Nippon Shokubai Co., Ltd (registered trademark) (grades: BPA328, BPA307) manufactured by Ltd can also be used.

< ingredient (C) >

The flake of the present invention may contain metal particles as the component (C). By containing the metal particles in the sheet, the density of the sheet can be increased while satisfying desired sound velocity, heat resistance, and acoustic wave sensitivity. Further, by adjusting the content of the metal particles in the sheet, the density of the sheet can be easily adjusted, and the acoustic impedance of the obtained acoustic matching layer can be adjusted to a desired level. The metal particles may also be surface treated.

The surface treatment of the metal particles is not particularly limited, and a general surface treatment technique can be applied. Examples thereof include oil treatment with hydrocarbon oil, ester oil, lanolin and the like, silicone treatment with dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane and the like, treatment with fluorine compounds containing perfluoroalkyl esters, perfluoroalkylsilanes, perfluoropolyethers, polymers having perfluoroalkyl groups and the like, treatment with silane coupling agents such as 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and the like, a treatment method such as a titanate coupling agent treatment with isopropyl triisostearoyl titanate, isopropyl tri (dioctyl pyrophosphate) titanate or the like, a metal soap treatment, an amino acid treatment with acyl glutamic acid or the like, a lecithin treatment with hydrogenated egg yolk lecithin or the like, a collagen treatment, a polyethylene treatment, a moisture retention treatment, an inorganic compound treatment, a mechanochemical treatment or the like.

The metal constituting the metal particles is not particularly limited. The metal atoms may be used alone or as carbides (e.g., tungsten carbide (WC)), nitrides, or borides of the metal atoms. Further, an alloy may be formed. Examples of the kind of alloy include high tensile steel (Fe-C), chromium-molybdenum steel (Fe-Cr-Mo), manganese-molybdenum steel (Fe-Mn-Mo), stainless steel (Fe-Ni-Cr), 42 alloy, invar (Fe-Ni), iron-cobalt (Fe-Co), silicon steel (Fe-Si), red copper, Tom Vac (Cu-Zn), copper-nickel-zinc alloy (Cu-Zn-Ni), bronze (Cu-Sn), cupronickel (Cu-Ni), red copper (Cu-Au), constantan alloy (Cu-Ni), aluminum alloy (Al-Cu), hastelloy (Ni-Mo-Cr-Fe), Monel (Ni-Cu), Inconel (Ni-Cr-Fe), nickel-chromium alloy (Ni-Cr), ferromanganese (Mn-Fe), Cemented carbide (WC/Co), and the like.

The metal atom constituting the metal particle preferably contains at least one of metal elements of groups 4 to 13 of the periodic table from the viewpoint of versatility and easiness of surface modification, and more preferably contains at least one of metal elements of groups 6 or 8 of the periodic table from the viewpoint of versatility and surface modification.

The metal atom more preferably contains at least one of Zn, In, Au, Ag, Co, Zr, W, Ta, Fe, Cu, Ni, Nb, Pt, Mn, and Mo from the viewpoint of versatility and surface modification, and further preferably contains at least one of Fe, Mo, and W from the viewpoint of versatility.

The particle size of the metal particles used in the present invention is preferably 0.01 to 100 μm, and more preferably 1 to 10 μm, from the viewpoint of dispersion stability in a composition for forming the acoustic matching sheet of the present invention described later and improvement of acoustic wave sensitivity of the sheet of the present invention. The "particle diameter" of the metal particles is an average primary particle diameter.

Here, the average primary particle size represents a volume average particle size. The volume average particle diameter was determined as follows.

The metal particles were added to methanol to be 0.5 mass%, and ultrasonic waves were applied for 10 minutes, thereby dispersing the metal particles. The particle size distribution of the metal particles treated in this manner was measured by a laser diffraction scattering particle size distribution measuring apparatus (manufactured by HORIBA, ltd., trade name: LA950V2), and the volume-based median particle diameter was taken as a volume average particle diameter. The median particle diameter corresponds to cumulative 50% when the particle diameter distribution is expressed as cumulative distribution.

In the sheet of the present invention, the content of each of the components (a) and (B) is not particularly limited as long as it can be produced by various methods, and can be appropriately adjusted depending on the target acoustic impedance and the like.

In the sheet of the present invention, the contents of the components (a) to (C) may be appropriately adjusted according to the target acoustic impedance and the like. For example, when the acoustic matching layer is a multilayer, the content of the component (C) in the sheet used for the acoustic matching layer on the piezoelectric element side is relatively large, the content of the component (C) in the sheet used for the acoustic matching layer on the acoustic lens side is relatively small, or the component (C) is not used. In this way, the acoustic impedance can be inclined from the piezoelectric element side to the acoustic lens side, and the propagation of the acoustic wave can be made more efficient.

Specifically, the contents of the components (a) to (C) can be determined as appropriate within the following ranges.

Content of component (B): the amount of the component (A) is preferably 1 to 60 parts by mass, more preferably 3 to 50 parts by mass, and still more preferably 5 to 40 parts by mass, based on 100 parts by mass of the component (A)

Content of component (C): the content of the component (A) is preferably 300 to 1050 parts by mass, more preferably 350 to 1000 parts by mass, and still more preferably 400 to 950 parts by mass, based on 100 parts by mass of the component (A)

The content of the component (B) is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, more preferably 2.5 parts by mass or more, and further preferably 3.5 parts by mass or more, per 100 parts by mass of the component (C). The upper limit is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and further preferably 6 parts by mass or less.

The sheet of the present invention may be composed of the component (a) and the component (B), or the component (a), the component (B) and the component (C). Further, components other than these may be contained within a range not impairing the effects of the present invention. As the component (other component) other than the component (C) in the components other than the components (a) and (B), for example, at least one of a curing retarder, a dispersant, a pigment, a dye, an antistatic agent, an antioxidant, a flame retardant, a thermal conductivity improver, and the like can be appropriately blended.

In the sheet of the present invention, the total content of each of the components (a), (B), and (C) is preferably 80% by mass or more, and more preferably 90% by mass or more.

The composition for an acoustic matching layer of the present invention (hereinafter, also referred to as "the composition of the present invention") contains the following components (a1) and (B1).

(A1) The method comprises the following steps At least one of resin and rubber

(B1) The method comprises the following steps At least one of resin particles and rubber particles having a lower sound velocity than the component (A1) and a number average particle diameter of 1.0 [ mu ] m or less

Examples of the resin of the component (a1) include the resins and rubbers listed in the above (a). However, when the component (a1) is a thermosetting resin or rubber, the component is not limited to a cured state, and may be in a state before curing. That is, the composition of the present invention may also be a composition for forming an acoustic matching sheet. In this case, the components (a1) and (B1) may be dissolved or dispersed in a solvent. As the component (B1), the above-mentioned component (B) can be used.

The composition of the present invention may contain the above-mentioned component (C) and may contain the other components.

< ingredient (D) >

The composition of the present invention may contain a curing agent as the component (D) depending on the kind of the component (A1).

For example, in the case of using an epoxy resin as the component (a1), the composition of the present invention preferably contains a polyamine compound. When a rubber is contained as the component (a1) and the rubber is cured (crosslinked), the composition of the present invention preferably contains an organic peroxide.

The composition of the present invention is molded into a sheet form, and cut or cut into a desired thickness, shape or the like as needed, thereby obtaining the acoustic matching sheet of the present invention. The acoustic matching sheet serves as an acoustic matching layer of the acoustic wave probe. The structure of the acoustic wave probe including the acoustic matching layer will be described later. The composition of the present invention may be in the form of a material set for acoustic matching sheets, in which the main agent containing the component (a1) and the component (B1) and the curing agent containing the component (D) are separated from each other. In the present invention, the term "composition" is used in a broader sense than usual. That is, in the present invention, such a form of the group is also included in the composition. When the acoustic matching sheet is formed, the main agent and the curing agent may be mixed and used to form the acoustic matching sheet.

In the production of a sheet, when the composition of the present invention contains a thermosetting component, it is preferable to form the sheet into a desired sheet in a low-temperature region where no curing reaction occurs or the curing rate is slow, and then cure the formed product by heating or the like as necessary to produce an acoustic matching sheet or a precursor sheet thereof. That is, in this case, the acoustic matching sheet of the present invention is a cured product obtained by curing the composition of the present invention to form a three-dimensional network structure.

When the composition of the present invention does not contain a thermosetting component, it is preferably produced by various methods depending on the material, such as injection molding and coating molding.

(polyamine Compound)

The polyamine compound used in the present invention preferably contains at least one polyamine compound represented by the following general formula (I) as a curing component which acts on an epoxy resin to cure the epoxy resin.

[ chemical formula 1]

General formula (I)

In the general formula (I), n represents an integer of 2 to 20 (preferably 3 to 20). L represents an n-valent aliphatic hydrocarbon group having at least one oxygen atom embedded in an aliphatic hydrocarbon chain or an n-valent group having an aromatic ring and an aliphatic hydrocarbon group having at least one oxygen atom.

The polyamine compound preferably contains at least one polyamine compound represented by any one of the following general formulae (II), (III), and (IV).

[ chemical formula 2]

General formula (II)

In the general formula (II), s represents an integer of 1 to 100, and n1 represents an integer of 2 to 20. L is¹Represents an n 1-valent aliphatic hydrocarbon group having 1 to 20 carbon atoms or an n 1-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, L²Represents an aliphatic hydrocarbon chain having 2 to 6 carbon atoms.

The aliphatic hydrocarbon group and the aliphatic hydrocarbon chain may be linear or branched.

s is preferably an integer of 1 to 50, more preferably an integer of 2 to 20.

n1 is preferably an integer of 1 to 15, more preferably an integer of 2 to 6, and further preferably 3 or 4.

From L¹The aliphatic hydrocarbon group represented above is preferably an n 1-valent aliphatic hydrocarbon group having 2 to 15 carbon atoms, more preferably an n 1-valent aliphatic hydrocarbon group having 3 to 10 carbon atoms, and still more preferably an n 1-valent aliphatic hydrocarbon group having 5 or 6 carbon atoms.

From L¹The aromatic hydrocarbon group is preferably an n 1-valent aromatic hydrocarbon group having 6 to 15 carbon atoms, more preferably an n 1-valent aromatic hydrocarbon group having 6 to 10 carbon atoms, and still more preferably n 1-valent benzene.

L²More preferably an aliphatic hydrocarbon chain having 2 to 4 carbon atoms, and still more preferably an aliphatic hydrocarbon chain having 2 or 3 carbon atoms.

[ chemical formula 3]

General formula (III)

In the general formula (III), t represents an integer of 1 to 100, and n2 represents an integer of 1 to 19.

L³Represents an (n2+1) -valent aliphatic hydrocarbon group having 1 to 20 carbon atoms or an (n2+1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms, L⁴Represents an aliphatic hydrocarbon chain having 2 to 6 carbon atoms.

In order to further increase the fracture energy of the acoustic matching layer and further reduce the variation in acoustic characteristics, t is preferably an integer of 1 to 50, and more preferably an integer of 2 to 20.

n2 is preferably an integer of 2 to 19, more preferably an integer of 2 to 5, and further preferably 3.

From L³The aliphatic hydrocarbon group represented above is preferably an (n2+1) -valent aliphatic hydrocarbon group having 2 to 10 carbon atoms, more preferably an (n2+1) -valent aliphatic hydrocarbon group having 2 to 6 carbon atoms, and still more preferably an (n2+1) -valent aliphatic hydrocarbon group having 2 to 4 carbon atoms.

From L³The aromatic hydrocarbon group represented is preferably a group having 6 carbon atomsA (n2+1) -valent aromatic hydrocarbon group of 15 or less, more preferably a (n2+1) -valent aromatic hydrocarbon group of 6 to 10 carbon atoms, and still more preferably a (n2+1) -valent benzene.

L⁴More preferably an aliphatic hydrocarbon chain having 2 to 4 carbon atoms, and still more preferably an aliphatic hydrocarbon chain having 2 or 3 carbon atoms.

[ chemical formula 4]

General formula (IV)

In the general formula (IV), u represents an integer of 1 to 100, n3 and n4 represent integers of 1 or more, and the total of n3 and n4 is 20 or less. L is⁵Represents an (n3+1) -valent aliphatic hydrocarbon group having 1 to 20 carbon atoms or an (n3+1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms. L is⁶Represents an (n4+1) -valent aliphatic hydrocarbon group having 1 to 20 carbon atoms or an (n4+1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms. L is⁷Represents an aliphatic hydrocarbon chain having 2 to 6 carbon atoms.

u is preferably an integer of 1 to 50, more preferably an integer of 2 to 20.

n3 and n4 are preferably integers of 2 to 10, more preferably integers of 2 to 5, and still more preferably 2 or 3.

From L⁵The aliphatic hydrocarbon group represented above is preferably an (n3+1) -valent aliphatic hydrocarbon group having 2 to 15 carbon atoms, more preferably an (n3+1) -valent aliphatic hydrocarbon group having 2 to 10 carbon atoms, and still more preferably an (n3+1) -valent aliphatic hydrocarbon group having 3 to 6 carbon atoms.

From L⁵The aromatic hydrocarbon group is preferably an (n3+1) -valent aromatic hydrocarbon group having 6 to 15 carbon atoms, more preferably an (n3+1) -valent aromatic hydrocarbon group having 6 to 10 carbon atoms, and still more preferably an (n3+1) -valent benzene.

From L⁶The aliphatic hydrocarbon group represented above is preferably an (n4+1) -valent aliphatic hydrocarbon group having 2 to 15 carbon atoms, more preferably an (n4+1) -valent aliphatic hydrocarbon group having 2 to 10 carbon atoms, and still more preferably an (n4+1) -valent aliphatic hydrocarbon group having 3 to 6 carbon atoms.

From L⁶The aromatic hydrocarbon group is preferably a (n4+1) -valent aromatic hydrocarbon group having 6 to 15 carbon atoms, more preferably a carbon atom(n4+1) -valent aromatic hydrocarbon groups having a numerator of 6 to 10, more preferably (n4+1) -valent benzene.

L⁷More preferably an aliphatic hydrocarbon chain having 2 to 4 carbon atoms, and still more preferably an aliphatic hydrocarbon chain having 2 or 3 carbon atoms.

The polyamine compound used in the present invention may have the following substituent T within a range not impairing the effects of the present invention.

Examples of the substituent T include the following groups.

Examples thereof include an alkyl group (preferably having 1 to 20 carbon atoms), an alkenyl group (preferably having 2 to 20 carbon atoms), an alkynyl group (preferably having 2 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms, but in the present invention, when referred to as an alkyl group, it usually represents a heterocyclic group containing cycloalkyl), an aryl group (preferably having 6 to 26 carbon atoms), an aralkyl group (preferably having 7 to 23 carbon atoms), a heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, more preferably a heterocyclic group having 5 or 6-membered ring having at least one oxygen atom, sulfur atom or nitrogen atom), an alkoxy group (preferably having 1 to 20 carbon atoms), an aryloxy group (preferably having 6 to 26 carbon atoms), but in the present invention, when referred to as an alkoxy group, it usually represents an aryloxy group containing an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms), an aryloxycarbonyl group (preferably having 6 to 26 carbon atoms), An amino group (preferably an amino group having 0 to 20 carbon atoms including an alkylamino group and an arylamino group), a sulfamoyl group (preferably an amino group having 0 to 20 carbon atoms), an acyl group (preferably a amino group having 1 to 20 carbon atoms), an aroyl group (preferably a carbon atom having 7 to 23 carbon atoms), but in the present invention, when called an acyl group, it usually means an aroyl group-containing group, an acyloxy group (preferably a carbon atom having 1 to 20 carbon atoms), an aroyloxy group (preferably a carbon atom having 7 to 23 carbon atoms, but in the present invention, when called an acyloxy group, it usually means an aroyloxy group-containing group), a carbamoyl group (preferably a carbon atom having 1 to 20 carbon atoms), an acylamino group (preferably a carbon atom having 1 to 20 carbon atoms), an alkylthio group (preferably a carbon atom having 1 to 20 carbon atoms), an arylthio group (preferably a carbon atom having 6 to 26 carbon atoms), an alkylsulfonyl group (preferably a carbon atom having 1 to 20 carbon atoms), an arylsulfonyl group (preferably a carbon atom having 6 to 22 carbon atoms), An alkylsilyl group (preferably having 1 to 20 carbon atoms), an arylsilyl group (preferably having 6 to 42 carbon atoms), and an alkaneAn oxysilyl group (preferably having 1 to 20 carbon atoms), an aryloxysilyl group (preferably having 6 to 42 carbon atoms), a phosphoryl group (preferably a phosphoryl group having 0 to 20 carbon atoms, for example, -OP (═ O) (R)^P)₂) A phosphono group (preferably a phosphono group having 0 to 20 carbon atoms, for example, -P (═ O) (R)^P)₂) A phosphinyl group (preferably a phosphinyl group having 0 to 20 carbon atoms, e.g., -P (R)^P)₂) A (meth) acryloyl group, a (meth) acryloyloxy group, a (meth) acryloylimino group ((meth) acrylamido group), a hydroxyl group, a sulfanyl group, a carboxyl group, a phosphoric acid group, a phosphonic acid group, a sulfonic acid group, a cyano group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom). R^pIs a hydrogen atom, a hydroxyl group or a substituent (preferably a group selected from the substituent T).

Each of the groups listed as the substituent T may be further substituted with the substituent T.

When the compound, the substituent, the linking group, or the like includes an alkyl group, an alkylene group, an alkenyl group, an alkenylene group, an alkynyl group, an alkynylene group, or the like, these groups may be cyclic or linear, may be linear or branched, and may be substituted or unsubstituted as described above.

Specific examples of the polyamine compound used in the present invention will be described below, but the present invention is not limited thereto.

[ chemical formula 5]

[ chemical formula 6]

[ chemical formula 7]

[ chemical formula 8]

[ chemical formula 9]

The polyamine compound used in the present invention can be synthesized by a conventional method. Further, commercially available products may be used.

The polyamine compound may be formed from the polyamine compound represented by the above general formula (I), and may contain other amine compounds (for example, tertiary amine compounds) in addition to the above polyamine compound within a range in which the effects of the present invention are not impaired. The content of the polyamine compound represented by the general formula (I) in the polyamine compound is preferably 80% by mass or more, and more preferably 90% by mass or more.

In the composition of the present invention, the equivalent ratio of the epoxy resin to the polyamine compound can be set, for example, to 0.5/1 to 1/0.5 (mole of epoxy group/mole of amino group × 2 (mole of active hydrogen)) -0.5/1 to 0.5.

When the composition of the present invention is prepared by mixing the main agent and the curing agent at the time of forming a sheet using the material set for acoustic matching sheets, the main agent and the curing agent are preferably used in a form in which the mass ratio of the epoxy resin to the polyamine compound is 99/1 to 20/80, and more preferably 90/10 to 40/60.

(organic peroxide)

Examples of the organic peroxide used in the present invention include organic peroxides generally used, such as hydroperoxides, dialkyl peroxides, peroxyesters, diacyl peroxides, and peroxyketals, which have at least carbon atoms and-O-bonds in the molecule.

Specifically, the following organic peroxides can be mentioned.

Hydroperoxide: p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1, 3, 3-tetramethylbutyl hydroperoxide, cumene hydroperoxide and tert-butyl hydroperoxide, etc

Dialkyl peroxides: 1, 3-bis (2-t-butylperoxyisopropyl) benzene, dicumyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, t-butylperoxyisopropyl benzene, di-t-hexyl peroxide, di-t-butyl peroxide, 2, 5-bis (t-butylperoxy) -2, 5-dimethyl-3-hexyne, and the like

Peroxyester: t-butylperoxybenzoate, t-butylperoxymaleate, t-butylperoxy-3, 5, 5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2, 5-bis (benzoylperoxy) -2, 5-dimethylhexane, t-butylperoxyacetate and the like

Diacyl peroxides: bis (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide, dibenzoyl peroxide, bis (4-methylbenzoyl) peroxide and the like

Peroxyketal: 1, 1-bis (t-hexylperoxy) -3, 3, 5-trimethylcyclohexane, 1-bis (t-hexylperoxy) cyclohexane, 1-bis (t-butylperoxy) -2-methylcyclohexane, 1-bis (t-butylperoxy) cyclohexane, 2-bis (t-butylperoxy) butane, n-butyl-4, 4-bis (t-butylperoxy) valerate, 2-bis (4, 4-bis (t-butylperoxy) cyclohexyl) propane and the like

One kind of the organic peroxide may be used alone, or two or more kinds may be used simultaneously. The content of the organic peroxide in the composition of the present invention may be 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less, based on 100 parts by mass of the content of the component (a). The lower limit is not particularly limited, but is actually 0.1 part by mass or more.

< preparation of composition for acoustic matching layer >

The composition for an acoustic matching layer of the present invention can be kneaded using, for example, a kneader, a pressure kneader, a banbury mixer (continuous kneader), a two-roll kneader, or the like to obtain components constituting the composition for an acoustic matching layer. This makes it possible to obtain a composition for an acoustic matching layer in which the components (a1) and (B1) are dispersed.

When an epoxy resin is used as the component (a1) and a polyamine compound is used as the curing agent, the curing reaction of the epoxy resin may progress with time in the composition of the present invention. Therefore, the properties of the composition may change with time and may be unstable. However, for example, by mixing and storing the above composition at a temperature of-10 ℃ or lower, a composition in which the respective components are stably maintained without causing a curing reaction or sufficiently suppressing the curing reaction can be produced.

When a material set for acoustic matching sheets containing a main agent composed of the components (a1) and (B1) and a curing agent is prepared, the main agent can be obtained by kneading the components (a1) and (B1). In the production of the acoustic matching sheet, the composition of the present invention is prepared by mixing the main agent and the curing agent, and the acoustic matching sheet or its precursor sheet can be formed by molding the composition and curing it.

The kneading and molding are preferably performed while removing bubbles, and therefore, the kneading and molding are usually performed under reduced pressure.

The temperature condition for the kneading is preferably 5 to 40 ℃ and more preferably 10 to 30 ℃.

[ Acoustic wave Probe ]

The acoustic wave probe of the present invention has the sheet of the present invention as an acoustic matching layer. The acoustic matching layer may have a multilayer structure in which a plurality of sheets of the present invention are stacked. In the multilayer structure, the acoustic impedance is preferably inclined from the piezoelectric element side to the acoustic lens side to a value close to the living body. The number of laminated sheets and the thickness of each sheet can be appropriately adjusted according to the thickness of the acoustic matching layer itself to be formed. The number of the sheets can be, for example, 2 to 50, preferably 3 to 20. The thickness of each sheet of the present invention is, for example, 1 to 500. mu.m.

Fig. 1 shows an example of the structure of the acoustic wave probe according to the present invention. The acoustic wave probe shown in fig. 1 is an ultrasonic probe in an ultrasonic diagnostic apparatus. The ultrasonic probe is a probe that uses ultrasonic waves as acoustic waves in an acoustic wave probe. Therefore, the basic structure of the ultrasonic probe can be applied to the acoustic wave probe as it is.

< ultrasonic Probe >

The ultrasonic probe 10 is a main component of an ultrasonic diagnostic apparatus, and has a function of transmitting and receiving an ultrasonic beam while generating ultrasonic waves. In the configuration of the ultrasonic probe 10, as shown in fig. 1, an acoustic lens 1, an acoustic matching layer 2, a piezoelectric element layer 3, and a backing 4 are provided in this order from the distal end (surface that comes into contact with a living body as an examination subject). In recent years, for the purpose of receiving harmonics, it has also been proposed to form a transmission ultrasonic transducer (piezoelectric element) and a reception ultrasonic transducer (piezoelectric element) of different materials and to form a laminated structure.

(piezoelectric element layer)

The piezoelectric element layer 3 is a portion where ultrasonic waves are generated, electrodes are attached to both sides of the piezoelectric element, and when a voltage is applied, the piezoelectric element repeats contraction and expansion and vibrates, thereby generating ultrasonic waves.

As a material constituting the piezoelectric element, crystal and LiNbO are widely used₃、LiTaO₃And KNbO₃Etc. single crystals, ZnO, AlN, etc. thin films, and Pb (Zr, Ti) O₃The piezoelectric ceramic is a so-called ceramic inorganic piezoelectric body obtained by subjecting a sintered body or the like to a polarization treatment. In general, PZT with good conversion efficiency is used: piezoelectric ceramics such as lead zirconate titanate.

Further, a wider bandwidth sensitivity is required for the piezoelectric element for detecting the received wave at the high frequency side. Therefore, as a piezoelectric element suitable for a high frequency and a wide frequency band, an organic piezoelectric body using an organic polymer material such as polyvinylidene fluoride (PVDF) is used.

Furthermore, japanese patent application laid-open publication No. 2011-071842 and the like describe cMUT that exhibits excellent short pulse characteristics and broadband characteristics, is excellent in mass productivity, can obtain a layer structure with less characteristic variation, and utilizes mems (micro fluidic Mechanical systems) technology.

In the present invention, any piezoelectric element material can be preferably used.

(backing material)

The backing material 4 is provided on the back surface of the piezoelectric element layer 3, and helps to improve the distance resolution in the ultrasonic diagnostic image by reducing the pulse width of the ultrasonic wave by suppressing excessive vibration.

(Acoustic matching layer)

The acoustic matching layer 2 is provided to reduce the difference in acoustic impedance between the piezoelectric element layer 3 and the subject, and to efficiently transmit and receive ultrasonic waves.

(Acoustic lens)

The acoustic lens 1 is provided to focus the ultrasonic waves in the slice direction by refraction and to improve resolution. Furthermore, it is required to bring the ultrasonic wave into close contact with the living body as the subject and to provide acoustic impedance (1.4 to 1.7X 10 in the human body) between the ultrasonic wave and the living body⁶kg/m²Sec) matching and the ultrasonic attenuation amount of the acoustic lens 1 itself are small.

That is, the acoustic lens 1 is made of a material having an acoustic velocity sufficiently lower than the acoustic velocity of a human body, and having an acoustic impedance close to the value of human skin, thereby improving the ultrasonic wave transmission/reception sensitivity.

The operation of the ultrasonic probe 10 having such a configuration will be described. A voltage is applied to electrodes provided on both sides of the piezoelectric element to resonate the piezoelectric element layer 3, and an ultrasonic signal is transmitted from the acoustic lens to the subject. At the time of reception, the piezoelectric element layer 3 is vibrated by a reflected signal (echo signal) from the subject, and the vibration is electrically converted into a signal to obtain an image.

[ method for manufacturing Acoustic Probe ]

The acoustic wave probe of the present invention can be produced by a conventional method except that the composition of the present invention is used. That is, the method for manufacturing an acoustic wave probe of the present invention includes forming an acoustic matching layer on a piezoelectric element using the composition of the present invention. The piezoelectric element can be arranged on the backing material by conventional methods.

And, the acoustic lens is formed on the acoustic matching layer by a conventional method using a material for forming the acoustic lens.

[ Acoustic wave measuring apparatus ]

The acoustic wave measurement device of the present invention includes the acoustic wave probe of the present invention. The acoustic wave measurement device has a function of displaying the signal intensity of a signal received by the acoustic wave probe or imaging the signal.

The acoustic wave measurement device of the present invention is preferably an ultrasonic measurement device using an ultrasonic probe.

Examples

Hereinafter, the present invention will be described in further detail with reference to examples using ultrasonic waves as sound waves. The present invention is not limited to ultrasonic waves, and acoustic waves of audible frequencies may be used as long as an appropriate frequency is selected according to the subject, the measurement conditions, and the like. Hereinafter, room temperature means 25 ℃.

[ Synthesis examples ]

<1> preparation of composition for acoustic matching layer

(1) Preparation of composition for acoustic matching layer used in example 1

In a state where 100 parts by mass of metal particles (iron powder (Fe) (EW-I (trade name) manufactured by BASF CORPORATION), 11 parts by mass of epoxy resin (bisphenol a diglycidyl ether ("jER 825" (trade name), epoxy equivalent 170) manufactured by Mitsubishi Chemical CORPORATION) and 4 parts by mass of polybutadiene particles were decompressed to 1.0Pa at room temperature by "Awatori Rentaro) ARV-310 (trade name, manufactured by think CORPORATION)", defoaming was performed at 1800rpm while stirring for 4 minutes, in a state where 10 parts by mass of a curing agent (D-1) represented by the following chemical formula was reduced in pressure to 1.0Pa at room temperature by "Awatori Rentaro (rotation and revolution mixer) ARV-310 (trade name, manufactured by THINKY CORPORATION)", the composition for an acoustic matching layer used in example 1 was prepared by defoaming for 4 minutes while stirring at 1800 rpm.

[ chemical formula 10]

(2) Preparation of compositions for acoustic matching layers used in examples 2 to 34 and comparative examples 1 to 11

Compositions for acoustic matching layers used in examples 2 to 34 and comparative examples 1 to 11 were prepared in the same manner as in the preparation of the composition for acoustic matching layers used in example 1, except that the compositions described in table 1 below were changed.

(3) Preparation of composition for acoustic matching layer used in example 35

The composition for an acoustic matching layer used in example 35 was prepared by kneading (280 ℃)100 parts by mass of metal particles (iron powder (Fe) (EW-I (trade name) manufactured by BASF corporation), 11 parts by mass of polyamide resin (nylon 12(KUREHA EXTRON co., ltd.) and 4 parts by mass of polybutadiene particles with an extrusion kneader.

(4) Preparation of compositions for acoustic matching layers used in examples 36 to 41 and comparative examples 12 to 15

Compositions for acoustic matching layers used in examples 36 to 41 and comparative examples 12 to 15 were prepared in the same manner as in the preparation of the composition for acoustic matching layers used in example 35, except that the compositions described in table 1 below were changed.

(5) Preparation of composition for acoustic matching layer used in example 42

The composition for an acoustic matching layer used in example 42 was prepared by kneading 100 parts by mass of metal particles (iron powder (Fe) (EW-I (trade name) manufactured by BASF Corporation), 11 parts by mass of polyisoprene rubber ("Nipol IR 2200" (trade name) manufactured by Zeon Corporation, 1 part by mass of dicumyl peroxide (PERCUMYLD-40 manufactured by NOF Corporation), and 4 parts by mass of polybutadiene particles at 80 ℃.

(6) Preparation of compositions for acoustic matching layers used in examples 43 to 48 and comparative examples 16 to 21

Compositions for acoustic matching layers used in examples 43 to 48 and comparative examples 16 to 21 were prepared in the same manner as in the preparation of the composition for acoustic matching layers used in example 42, except that the compositions described in table 1 below were changed.

<2> production of Acoustic matching sheet

(1) Preparation of Acoustic matching sheet of example 1

The prepared composition for an acoustic matching layer was poured into a mold having a length of 5cm, a width of 5cm and a height of 2mm, cured at 60 ℃ for 18 hours, and then cured at 150 ℃ for 1 hour, thereby producing an acoustic matching sheet.

(2) Production of Acoustic matching sheets of examples 2 to 34 and comparative examples 1 to 11

An acoustic matching sheet was produced in the same manner as the production of the acoustic matching sheet of example 1, except that the composition for an acoustic matching layer used in examples 2 to 34 and comparative examples 1 to 11 was used instead of the composition for an acoustic matching layer used in example 1.

(3) Preparation of Acoustic matching sheet of example 35

The composition for an acoustic matching layer used in example 1 was placed in a mold having a length of 5cm, a width of 5cm and a height of 2mm, pressed at the melting point of component (a) +10 ℃ for 5 minutes, and cooled, thereby producing an acoustic matching sheet.

(4) Production of Acoustic matching sheets of examples 36 to 41 and comparative examples 12 to 15

An acoustic matching sheet was produced in the same manner as in the production of the acoustic matching sheet of example 35, except that the composition for an acoustic matching layer used in examples 36 to 41 and comparative examples 12 to 15 was used instead of the composition for an acoustic matching layer used in example 35.

(5) Production of Acoustic matching sheet used in example 42

The composition for an acoustic matching layer used in example 42 was placed in a mold having a length of 5cm, a width of 5cm and a height of 2mm, and pressed at a temperature of 120 ℃ for 30 minutes, thereby producing an acoustic matching sheet.

(6) Production of Acoustic matching sheets used in examples 43 to 48 and comparative examples 16 to 21

An acoustic matching sheet was produced in the same manner as in the production of the acoustic matching sheet used in example 42, except that the composition for an acoustic matching layer used in examples 43 to 48 and comparative examples 16 to 21 was used instead of the composition for an acoustic matching layer used in example 42.

[ test examples ]

<1> measurement of Sound velocity

(1) Sound velocity of component (A)

The local elastic modulus of the component (a) was calculated by a scanning type probe microscope (SPM-9700 (trade name) manufactured by Shimadzu Corporation) using JKR theory, and the sound velocity of the component (a) was calculated by the following formula using the density of the component (a). The local elastic modulus was calculated by pressing the cantilever into the depth of 5nm with respect to the acoustic matching plate. The composition is clarified by sampling a small amount of the component (a) from the acoustic matching sheet and analyzing the sample with an analyzer such as NMR, IR, thermal decomposition GC-MS, or the like, and the density is determined from the composition.

Sound velocity (local modulus of elasticity/density)^1/2

(2) Sound velocity of component (B)

The local elastic modulus of the component (B) was calculated by a scanning type probe microscope (SPM-9700 manufactured by Shimadzu Corporation) using JKR theory, and the sound velocity of the component (B) was calculated by the following formula using the density of the component (B). The local elastic modulus was calculated by pressing the cantilever into the depth of 5nm with respect to the acoustic matching plate. The composition is clarified by sampling a small amount of the component (B) from the acoustic matching chip and analyzing the sample with an analyzer such as NMR, IR, thermal decomposition GC-MS, or the like, and the density is determined from the composition.

Sound velocity (local modulus of elasticity/density)^1/2

(3) Sound velocity of Sound matching piece (Sound velocity (S) of Table 1 described later)

With respect to the acoustic matching sheet manufactured as described above, sound velocities near the four corners and at 5 points in the center of the sheet (the entire inside of a circle having a diameter of 1.5cm (small probe size of monaural sound channel) in each measurement portion) were measured at 25 ℃ using a sound circulation (sound-around) sound velocity measurement device (manufactured by ultrastronics engineering co., ltd., product name "UVM-2 type") according to JIS Z2353(2003), and the arithmetic average value thereof was taken as the sound velocity of the acoustic matching sheet. The obtained sound velocity was evaluated by substituting the sound velocity into the following evaluation criteria. The term "D" or more means that the test is acceptable.

Evaluation criteria-

A: the sound velocity is reduced by 10% or more compared to a corresponding acoustic matching sheet not containing resin particles.

B: the sound velocity is reduced by 7.5% or more and less than 10% as compared with a corresponding acoustic matching sheet containing no resin particles.

C: the sound velocity is reduced by 5% or more and less than 7.5% as compared with a corresponding acoustic matching sheet containing no resin particles.

D: the sound velocity is reduced by 2.5% or more and less than 5% as compared with a corresponding acoustic matching sheet containing no resin particles.

E: the sound velocity is the same or reduced by less than 2.5% compared to a corresponding acoustic matching sheet that does not contain resin particles.

The phrase "corresponding acoustic matching sheet containing no resin particles" means that examples 1 to 7 and 11 to 34 and comparative examples 1 to 3 and 6 to 11 are comparative example 4, examples 8 to 10 are comparative example 5, examples 35 to 41 and comparative examples 12 to 14 are comparative example 15, and examples 42 to 48 and comparative examples 16 to 18, 20 and 21 are comparative example 19. The same applies to the following test examples.

<2> measurement of number average particle diameter of component (B)

The end face of the acoustic matching sheet was observed in a field of view containing 100 or more particles using a scanning electron microscope (SU 8030 (trade name) manufactured by Hitachi High-Technologies Corporation), 100 pieces were randomly extracted from the component (B) in the field of view, and the number average particle diameter thereof was measured, thereby calculating the number average particle diameter of the component (B) (resin particles).

The acoustic matching sheet whose end face could not be observed by the scanning electron microscope was observed by the freeze transmission electron microscopy. Freezing was performed by Vitrobot Mark IV (trade name) manufactured by FEI Company Japan ltd., 100 pieces were randomly extracted from component (B) in the visual field by a transmission electron microscope (JEM-2010 (trade name) manufactured by JEOL ltd), and their number average particle diameters were measured and calculated.

When the particles were not perfectly round, particles having a ratio of the vertical to horizontal diameters of at most 0.7 were extracted and measured.

<3> Heat resistance test

The heat resistance was evaluated by calculating the glass transition temperature of the viscoelasticity of the acoustic matching sheet using a viscoelasticity measuring apparatus (manufactured by Seiko Instruments inc., device name "DMS 6100"). The measurement was performed at 1Hz, and the temperature at which tan. delta. becomes the maximum value was defined as the glass transition temperature. The glass transition temperature was evaluated by substituting it into the following evaluation criteria. The term "C" or more means that the test is acceptable.

Evaluation criteria-

A: the glass transition temperature is the same or less than 5 ℃ as compared to a corresponding acoustic matching sheet not containing resin particles.

B: the temperature is lower by 5 ℃ or more and less than 7 ℃ than that of a corresponding acoustic matching sheet containing no resin particles.

C: the temperature is lower by 7 ℃ or more and less than 9 ℃ than that of a corresponding acoustic matching sheet containing no resin particles.

D: the temperature is lower by 9 ℃ or more and less than 10 ℃ than that of a corresponding acoustic matching sheet containing no resin particles.

E: the temperature is 10 ℃ or higher lower than that of a corresponding acoustic matching sheet containing no resin particles.

<4> Acoustic wave (ultrasonic) sensitivity test

A10 MHz sine wave signal (1 wave) output from an ultrasonic oscillator (IWATSU TEST impulse corporation, manufactured by functional signal generator, trade name "FG-350") was input to an ultrasonic probe (manufactured by JAPAN probe), and an ultrasonic pulse wave having a center frequency of 10MHz was generated in water from the ultrasonic probe. The magnitude of the amplitude of the generated ultrasonic wave before and after passing through the obtained acoustic matching sheet having a thickness of 2mm was measured using an ultrasonic receiver (manufactured by Panasonic Corporation, oscilloscope, trade name "VP-5204A") under an environment of water temperature 25 ℃, and the acoustic wave (ultrasonic wave) sensitivities were compared, thereby comparing the acoustic wave (ultrasonic wave) attenuation amounts of the respective materials.

The acoustic wave (ultrasonic wave) sensitivity is a numerical value obtained by the following calculation formula.

In the following calculation formula, Vin represents a voltage peak value of an input wave having a half-value width of 50nsec or less generated by an ultrasonic oscillator. Vs represents a voltage value obtained when the generated acoustic wave (ultrasonic wave) passes through the sheet and the ultrasonic oscillator receives the acoustic wave (ultrasonic wave) reflected from the opposite side of the sheet. The higher the sensitivity of the acoustic wave (ultrasonic wave), the smaller the attenuation of the acoustic wave (ultrasonic wave).

Acoustic (ultrasonic) sensitivity 20 × Log (Vs/Vin)

The acoustic wave (ultrasonic wave) sensitivity was evaluated according to the following evaluation criteria. In this test, "C" or more is a pass level.

Evaluation criteria-

A: the sensitivity was not reduced as compared with the corresponding acoustic matching sheet containing no resin particles.

B: the sensitivity was reduced to less than 2.5% compared to a corresponding acoustic matching sheet that did not contain resin particles.

C: the sensitivity is reduced by 2.5% or more and less than 5.0% as compared with a corresponding acoustic matching sheet containing no resin particles.

D: the sensitivity is reduced by 5.0% or more and less than 7.5% as compared with a corresponding acoustic matching sheet containing no resin particles.

E: the sensitivity is reduced by 7.5 or more compared with a corresponding acoustic matching sheet containing no resin particles.

Examples 1 to 48, comparative examples 1 to 3, 6 to 9, 12 to 14, and 16 to 18: the difference between the sound velocity of the component (A) and the sound velocity of the component (B) is 50 to 1500m/s as confirmed by the Scanning Probe Microscope (SPM).

Comparative examples 20 and 21: the difference between the "sound velocity of component (A)" and the "sound velocity of component (B)" was confirmed to be-50 to-1500 m/s by SPM.

Similarly to the above-described production of the acoustic matching sheet, if a sheet having a vertical length of 5cm, a horizontal length of 5cm and a height of 2mm can be produced for the component (B), even if a sheet formed of the component (B) is produced, sound velocities at 5 points (the entire inner portion of a circle having a diameter of 1.5cm (small probe size of monaural sound channel) in the vicinity of the four corners and the central portion of the sheet are measured at 25 ℃ using an acoustic circulation type sound velocity measuring apparatus (ltrasonics engineering co., ltd., product name "UVM-2 type") according to JIS Z2353(2003), and the arithmetic average thereof is used as the sound velocity of the component (B), the result substantially the same as that of the above-described method can be obtained.

Similarly, if the component (a) can be produced in the same manner as in the production of the acoustic matching sheet, even if a sheet made of the component (a) is produced, the sound velocities at 5 positions near the four corners and at the center of the sheet are measured, and the arithmetic average thereof is taken as the sound velocity of the component (a), the same result as in the above-described method can be obtained.

That is, it can be confirmed by these methods that "the sound velocity of the component (a)" to "the difference in sound velocity of the component (B)" are within the above range.

The density of the measuring portion in the vicinity of the four corners and 5 in the central portion of the sheet formed of the above-mentioned component (a) or the sheet formed of the component (B) can also be measured at 25 ℃ using an electron densitometer (Alfa Mirage co., ltd., product name "SD-200L") according to the density measuring method of method a (underwater substitution method) described in JIS K7112(1999), and the arithmetic average thereof can be used as the density of the component (a) or the component (B). The density of the measurement unit is the density of a sheet (10mm × 10mm square) cut out in a square of 10mm × 10mm square in the sound velocity measurement unit (circular shape having a diameter of 1.5 cm).

< notes >

[ component (A1) ]

(A-1) bisphenol A diglycidyl ether ("jER 825" (trade name), epoxy equivalent 170) manufactured by Mitsubishi Chemical Corporation

(A-2) bisphenol A diglycidyl ether ("jER 828" (trade name), epoxy equivalent 190), manufactured by Mitsubishi Chemical Corporation

(A-3) bisphenol A diglycidyl ether ("jER 834" (trade name), epoxy equivalent 230), manufactured by Mitsubishi Chemical Corporation

(A-4) bisphenol F diglycidyl ether ("EPICLON 830" (trade name), epoxy equivalent 170) manufactured by DIC Corporation

(A-5) epoxy novolac resin (manufactured by Sigma-Aldrich Co. LLC, product No. 406775, epoxy equivalent 170)

(A-6) bisphenol A propoxylate diglycidyl ether (manufactured by Sigma-Aldrich Co. LLC, epoxy equivalent 228)

(A-7)4, 4' -methylenebis (N, N-diglycidylaniline) (manufactured by Tokyo Chemical Industry Co., Ltd., epoxy equivalent 106)

(A-8) Nylon 12(KUREHA EXTRON CO., LTD. manufactured)

(A-9) Polyisoprene rubber ("Nipol IR 2200" (trade name) manufactured by Zeon Corporation

[ component (B1) ]

PBd: polybutadiene rubber particles (particles prepared according to the following method)

200 parts by mass of ultrapure water, 0.03 part by mass of tripotassium phosphate, 0.002 part by mass of disodium ethylenediaminetetraacetate, 0.001 part by mass of ferrous sulfate 7 hydrate, and 1.55 parts by mass of sodium laurylsulfate were charged into a pressurized container, and nitrogen substitution was performed. Then, 100 parts by mass of butadiene was added and heated to 45 ℃. 0.03 part by mass of p-menthane hydroperoxide and 0.10 part by mass of SFS were added to initiate polymerization. After 3 hours, 5 hours, and 7 hours from the initiation of polymerization, 0.025 parts by mass of p-menthane hydroperoxide was added. Further, disodium ethylenediaminetetraacetate 0.0006 part by mass and ferrous sulfate 7 hydrate 0.003 part by mass were additionally added 4, 6 and 8 hours after initiation of polymerization, respectively. After 15 hours from initiation of polymerization, the pressure was reduced to remove the residual monomer, thereby terminating the polymerization, and polybutadiene rubber particles containing a polybutadiene rubber as a main component were obtained. The number average particle diameter of the polybutadiene rubber particles was 0.1. mu.m.

By repeating the above polymerization using the obtained rubber particles as seed particles, polybutadiene rubber particles having a number average particle diameter shown in table 1 were obtained.

Silicone 1: silicone particles (particles prepared by pulverizing TOSPEARLXC99-A8808 (trade name) manufactured by Momentive Performance Materials Japan LLC)

Silicone 2: silicone particles (TOSPEARL 120A (trade name) manufactured by Momentive Performance Materials Japan LLC)

Silicone 3: silicone particles (TOSPEARL 130 (trade name) manufactured by Momentive Performance Materials Japan LLC)

Acrylic resin particle 1: acrylic resin particles (particles prepared by pulverizing Eposter MA1002 (trade name) manufactured by Nippon Shokubai Co., Ltd.)

Acrylic resin particle 2: acrylic resin particles (Eposter MA1002 (trade name) manufactured by Nippon Shokubai Co., Ltd.)

Acrylic resin particle 3: acrylic resin particles (Eposter MA1004 (trade name); manufactured by Nippon Shokubai Co., Ltd.)

PIP: polyisoprene rubber particles (particles prepared according to the following method)

Sodium dodecyl sulfate (5.60g), ultrapure water (86.50g), tert-butyl hydroperoxide (0.035g), and tert-dodecyl mercaptan (0.0053g) were charged into a glass reaction vessel (200mL) equipped with a cooling tube and a mechanical stirrer. The vessel was replaced with argon at 25 ℃ for 1 hour. Subsequently, isoprene (3.6g) and tetraethylenepentamine (0.033g) were added thereto, and the mixture was reacted for 24 hours while stirring at 450 rpm. After 24 hours from initiation of polymerization, the pressure was reduced to remove the residual monomer, thereby terminating the polymerization and obtaining polyisoprene rubber particles containing a polyisoprene rubber as a main component. The number average particle diameter of the polyisoprene rubber particles contained in the latex obtained was 0.2. mu.m.

The polymerization was repeated using the obtained rubber particles as seed particles, thereby obtaining polyisoprene rubber particles each having a number average particle diameter shown in table 1.

Liquid PBd: liquid polybutadiene (NIPPON SODA CO., LTD. manufactured B-1000 (trade name))

Silicone (non-particulate) (Shin-Etsu Silicone Co., Ltd., X-22-163 (trade name); manufactured by Ltd.)

In comparative examples 10 and 11, for comparison with examples, liquid PBd and Silicone (non-particulate) are described in the column of the component (R1).

[ component (C) ]

Fe: iron powder (EW-I (trade name) manufactured by BASF corporation, average particle diameter 2 μm)

Mo: molybdenum powder (JAPAN NEW METALS CO., manufactured by LTD., Mo-3 (trade name), average particle diameter 3 μm)

WC: tungsten carbide powder (WC 30S, average particle size 3 μm, manufactured by A.L.M.T.Corp.)

W: tungsten powder (W-U030, average particle diameter 3 μm, manufactured by A.L.M.T.Corp.)

[ component (D) ]

(D-1) curing agent represented by the above formula

(D-2) dicumyl peroxide ("PERCUMYLD-40" (trade name) manufactured by NOF CORPORATION)

"particle size" means the number average particle size.

The component (D) was not used in examples 35 to 41 and comparative examples 12 to 15. The component (A1) and the amount thereof are described.

"-" indicates that the corresponding component or the like is not used.

As is clear from Table 1, the sheets of comparative examples 1 to 3, 6, 7, 8, 9, 12 to 14, 16 to 18 and 21 using particles having a number average particle diameter exceeding 1.0 μm were at least insufficient in acoustic wave sensitivity. The sound velocity of the sheets of comparative examples 4, 5, 15 and 19 containing no component (B) was high. Further, the sheet of comparative example 10 using a liquid polybutadiene rubber and the sheet of comparative example 11 using a non-particulate silicone were insufficient in heat resistance. In the sheet of comparative example 20, the sound velocity of the component (B) was higher than that of the component (a), and the sound velocity was also high as the sheet.

On the other hand, the sheet of the present invention was acceptable in all the evaluation items.

The present invention and its embodiments have been described, but it is understood that without specific recitation, our invention is not limited to any of the details of the description, but rather should be construed broadly within its spirit and scope as defined in the appended claims.

The present application claims priority based on japanese patent application 2019-068736, which was filed on 3/29/2019, and which is hereby incorporated by reference as part of the description herein.

Description of the symbols

1-acoustic lens, 2-acoustic matching layer, 3-piezoelectric element layer, 4-backing material, 7-shell, 9-cord and 10-ultrasonic probe (probe).