Acoustic matching layer material, acoustic matching sheet, composition for acoustic matching layer material, acoustic wave probe, acoustic wave measuring device, and method for manufacturing acoustic wave probe

Abstract

Provided are an acoustic matching layered material, acoustic matching sheet, composition for acoustic matching layered material, acoustic wave probe, acoustic wave measurement device, and method for manufacturing acoustic wave probe, the acoustic matching layered material containing an epoxy resin (A) component have an epoxy equivalent of 140 or less, and metal particles (B) having a density at 20°C of 10 g / cm3 or more, and the content of particles (C) having a density at 20°C of less than 4.5 g / cm3 being less than 5 mass%.

Description

[Technical Field]

[0001] The present invention relates to an acoustic matching layer material, an acoustic matching sheet, a composition for an acoustic matching layer material, an acoustic wave probe, an acoustic wave measuring device, and a method for manufacturing an acoustic wave probe. [Background technology]

[0002] Acoustic wave measurement devices use an acoustic wave probe that irradiates an object under test, such as a living body, with acoustic waves, receives the reflected waves (echoes), and outputs a signal. The reflected waves received by this acoustic wave probe are converted into electrical signals and displayed as an image. Therefore, by using an acoustic wave probe, it is possible to visualize and observe the inside of the object under test.

[0003] The acoustic wave may be an ultrasonic wave, a photoacoustic wave, or the like, and is appropriately selected depending on the object to be examined and the measurement conditions. For example, an ultrasonic diagnostic apparatus, which is one type of acoustic wave measuring apparatus, transmits ultrasonic waves toward the inside of a subject, receives the ultrasonic waves reflected by tissue inside the subject, and displays them as an image. Furthermore, a photoacoustic wave measurement device, which is a type of acoustic wave measurement device, receives acoustic waves emitted from inside a test object due to the photoacoustic effect and displays them 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 onto the test object, the test object absorbs the electromagnetic wave, generates heat, and thermally expands, generating acoustic waves (typically ultrasound waves).

[0004] Since an acoustic wave measurement device transmits and receives acoustic waves to and from a test subject, the acoustic wave probe is required to match the acoustic impedance with that of the test subject (typically a human body). To meet this requirement, an acoustic wave probe is provided with an acoustic matching layer. This will be explained using a probe for an ultrasound diagnostic device (also called an ultrasound probe), which is a type of acoustic wave probe, as an example. An ultrasound probe comprises a piezoelectric element that transmits and receives ultrasound waves, and an acoustic lens that comes into contact with the living body, with an acoustic matching layer disposed between the piezoelectric element and the acoustic lens. Ultrasound emitted from the piezoelectric element passes through the acoustic matching layer and then through the acoustic lens to enter the living body. There is usually a difference in acoustic impedance (density x longitudinal wave sound velocity) between the acoustic lens and the living body. If this difference is large, ultrasound waves are more likely to be reflected by the surface of the living body, reducing the efficiency with which ultrasound waves enter the living body. For this reason, acoustic lenses are required to have acoustic impedance characteristics similar to those of living bodies. On the other hand, the difference in acoustic impedance between a piezoelectric element and a living body is generally large. Therefore, the difference in acoustic impedance between a piezoelectric element and an acoustic lens is also usually large. Therefore, when a piezoelectric element and an acoustic lens are stacked, ultrasound emitted from the piezoelectric element is reflected by the surface of the acoustic lens, reducing the efficiency of ultrasound incidence into the living body. To suppress this reflection of ultrasound, the above-mentioned acoustic matching layer is provided between the piezoelectric element and the acoustic lens. The acoustic impedance of the acoustic matching layer takes a value between the acoustic impedance of the living body or the acoustic lens and the acoustic impedance of the piezoelectric element, thereby improving the efficiency of ultrasound propagation from the piezoelectric element to the living body. In recent years, development has been progressing on acoustic matching layers that have a multilayer structure in which multiple acoustic matching sheets (sheet-like acoustic matching layer materials) are stacked, providing a gradient in acoustic impedance from the piezoelectric element side to the acoustic lens side, thereby improving the efficiency of ultrasound propagation.

[0005] For example, Patent Document 1 describes a technology for obtaining an acoustic matching layer (acoustic matching sheet) by using silica particles, glass particles, and metal particles (e.g., tungsten, zinc, aluminum, tin, silver, platinum, gold, etc.) in an epoxy resin in order to realize an acoustic matching sheet having a desired acoustic impedance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-296055 Summary of the Invention [Problem to be solved by the invention]

[0007] The acoustic matching layer disposed on the piezoelectric element side requires a high acoustic impedance of approximately 16 Mrayl. Simply using high-density metal particles to increase the acoustic impedance of the acoustic matching sheet reduces the longitudinal wave sound velocity, resulting in limitations on achieving high acoustic impedance. The inventors' research has revealed that by combining a certain amount of low-density particles with high-density metal particles, it is possible to suppress the reduction in the longitudinal wave sound velocity of the acoustic matching sheet while enjoying the benefits of high density. However, it has been found that using high-density metal particles in combination with low-density particles is likely to result in air bubbles being entrapped during the mixing of raw materials during the manufacturing process, which can result in air bubbles remaining in the resulting acoustic matching sheet, reducing yield. Furthermore, the resulting acoustic matching sheet tends to have poor mechanical strength and poor processability, such as cutting, due to the influence of residual air bubbles or low-density particles.

[0008] An object of the present invention is to provide an acoustic matching layer material that exhibits high acoustic impedance suitable for placement on the piezoelectric element side, has a low bubble content, and has sufficient mechanical strength; an acoustic matching sheet using the acoustic matching layer material; and a composition for an acoustic matching layer material that is suitable for preparing the acoustic matching layer material. Another object of the present invention is to provide an acoustic wave probe using the above acoustic matching sheet, and an acoustic wave measuring device using the same. Another object of the present invention is to provide a method for manufacturing an acoustic wave probe using the above acoustic matching layer material. [Means for solving the problem]

[0009] The present inventors have further investigated to obtain an acoustic matching layer material that exhibits a high acoustic impedance suitable for use as an acoustic matching layer on the piezoelectric element side, and have found that the raw materials for the acoustic matching layer material are epoxy resin with an epoxy equivalent of 140 or less and high density (10 g / cm 3It has been found that by combining the high-density metal particles with the metal particles described above, it is possible to effectively suppress the decrease in longitudinal wave sound velocity while enjoying the benefits of the high density of the material due to the high-density metal particles, and to achieve a sufficiently high acoustic impedance, and that the resulting acoustic matching layer material has a low content of bubbles and sufficient mechanical strength. The present invention was completed after further investigation based on these findings.

[0010] That is, the above-mentioned problems of the present invention have been solved by the following means. <1> Epoxy resin (A) with an epoxy equivalent of 140 or less and a density of 10 g / cm at 20°C 3 and the above metal particles (B), and the density at 20°C is 4.5 g / cm 3 The acoustic matching layer material has a content of particles (C) of less than 5 mass %. <2> The epoxy resin (A) component is a component derived from a compound represented by any one of the following general formulas (1) to (4): <1> The acoustic matching layer material according to claim 1. [ka] In general formula (1), Cy 1 indicates a ring. 1a represents a linking group, and L 1b represents a linking group containing a nitrogen atom. 1 is 1 or 2, and q 1 is 1 or 2, and r 1 is an integer between 1 and 3. [ka] In general formula (2), Cy 2 indicates a ring. 2a and L 2b represents an alkylene group, an alkanetriyl group, an oxygen atom, or a linking group formed by combining these. 2 is 1 or 2, and q 2 is 1 or 2, and r 2 is an integer between 1 and 3. [ka] In general formula (3), Cy 3 indicates a ring. 3a represents a linking group containing a nitrogen atom, and L 3b represents a linking group. 3 represents a linking group. 3 is 1 or 2, and q 3 is 1 or 2, and r 3 is an integer between 0 and 3, and s 3 is 2 or 3. However, the compound represented by general formula (3) has three or more epoxy groups. [ka] In general formula (4), Cy 4 indicates a ring. 4a and L 4b represents an alkylene group, an alkanetriyl group, an oxygen atom, or a linking group formed by combining these. 4 represents a linking group. 4 is 1 or 2, and q 4 is 1 or 2, and r 4 is an integer between 0 and 3, and s 4 is 2 or 3. However, the compound represented by general formula (4) has three or more epoxy groups. <3> the acoustic matching layer material contains a curing agent (D) component, and the curing agent (D) contains an amine curing agent; <1> or <2> The acoustic matching layer material according to claim 1. <4> the amine curing agent comprises an aromatic amine; <3> The acoustic matching layer material according to claim 1. <5> The epoxy resin component (A) has an aromatic hydrocarbon ring. <1> ~ <4> 10. The acoustic matching layer material according to claim 9, wherein the thickness of the acoustic matching layer is 100 nm. <6> Density at 25°C is 7.0 g / cm 3 That's all. <1> ~ <5> 10. The acoustic matching layer material according to claim 9, wherein the thickness of the acoustic matching layer is 100 nm. <7> The longitudinal wave velocity of the ultrasonic wave at 25°C is 2300 m / sec or more. <1> ~ <6> 10. The acoustic matching layer material according to claim 9, wherein the thickness of the acoustic matching layer is 100 nm. <8> The acoustic impedance at 25°C is 16 Mrayl or more. <1> ~ <7> 10. The acoustic matching layer material according to claim 9, wherein the thickness of the acoustic matching layer is 100 nm. <9> <1> ~ <8> 1. An acoustic matching sheet comprising the acoustic matching layer material according to any one of the above. <10> Epoxy resin (A) with an epoxy equivalent of 140 or less and a density of 10 g / cm at 20°C 3 and the above metal particles (B), and the density at 20°C is 4.5 g / cm 3 The content of particles (C) in the solid content is less than 5 mass%; <1> ~ <8> 10. A composition for an acoustic matching layer material for obtaining the acoustic matching layer material according to any one of claims 1 to 9. <11> <9> An acoustic wave probe having the acoustic matching sheet according to claim 1 as an acoustic matching layer. <12> <11> An acoustic wave measuring device comprising the acoustic wave probe according to claim 1. <13> The acoustic wave measuring device is an ultrasonic diagnostic device. <12> The acoustic wave measuring device according to claim 1. <14> On the piezoelectric element, <1> ~ <8> 10. A method for manufacturing an acoustic wave probe, comprising forming an acoustic matching layer using the acoustic matching layer material according to any one of the preceding items.

[0011] In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit. In this specification, the term "epoxy equivalent" refers to the number of grams of epoxy resin containing 1 gram equivalent of epoxy groups (g / eq), i.e., the value obtained by dividing the molecular weight of the epoxy resin by the number of epoxy groups contained in the epoxy resin. In this specification, when there are multiple substituents, linking groups, etc. (hereinafter referred to as "substituents, etc.") designated by a specific symbol, or when multiple substituents, etc. are simultaneously or alternatively specified, this means that the respective substituents, etc. may be the same or different from each other. Furthermore, even if not otherwise specified, when multiple substituents, etc. are adjacent, they may be linked to each other or condensed to form a ring. In this specification, the "group" of each group explained as an example of each substituent is used to mean both an unsubstituted form and a substituted form. For example, an "alkyl group" means an alkyl group which may have a substituent. Furthermore, when the number of carbon atoms in a group is limited, the number of carbon atoms in this group means the total number of carbon atoms including the substituent, unless otherwise specified. In this specification, the term "compound" is used to mean not only the compound itself, but also its salts and ions. It also means that compounds with partially modified structures are included as long as the effects of the present invention are not impaired. Furthermore, compounds that are not specified as substituted or unsubstituted may have any substituent as long as the effects of the present invention are not impaired. The same applies to substituents and linking groups. [Effects of the Invention]

[0012] The acoustic matching layer material of the present invention and the acoustic matching sheet using the acoustic matching layer material exhibit high acoustic impedance suitable for placement on the piezoelectric element side, contain few air bubbles, and have sufficient mechanical strength. Furthermore, the acoustic matching layer material can be obtained by curing the composition for the acoustic matching layer material of the present invention. The acoustic wave probe of the present invention includes the above acoustic matching sheet. The acoustic wave measuring device of the present invention also includes an acoustic wave probe. Furthermore, according to the method for manufacturing an acoustic wave probe of the present invention, an acoustic wave probe using the above acoustic matching layer material can be obtained. [Brief explanation of the drawings]

[0013] [Figure 1]FIG. 1 is a perspective view of an example of a convex ultrasonic probe, which is one aspect of an acoustic wave probe. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Acoustic matching layer material] The acoustic matching layer material of the present invention (hereinafter also simply referred to as "the layer material of the present invention") comprises an epoxy resin (A) component having an epoxy equivalent of 140 or less (a component derived from an epoxy resin (A) having an epoxy equivalent of 140 or less) and an epoxy resin (A) having a density of 10 g / cm at 20°C. 3 The metal particles (B) are contained. The layer material of the present invention has a density of 4.5 g / cm at 20°C. 3 The layer material of the present invention may contain particles (C) of less than 5 mass %, and the content of particles (C) in the layer material of the present invention is less than 5 mass %. Hereinafter, "epoxy resin (A) having an epoxy equivalent of 140 or less" may be simply referred to as "epoxy resin (A)." 3 The above metal particles (B) may be simply referred to as "metal particles (B)." 3 "Particles (C) less than 10 ... The shape of the layer material of the present invention is not particularly limited, and examples thereof include a sheet, a cylindrical shape, and a prismatic shape, with a sheet shape being preferred.

[0015] The layer material of the present invention is composed of an epoxy resin (A) component and has a high crosslink density. Therefore, the metal particles (B) are contained in a matrix with a high elastic modulus, which is thought to contribute to the achievement of high longitudinal wave sound velocity and thus high acoustic impedance. Furthermore, because high acoustic impedance can be achieved without the presence of particles (C), air bubbles are less likely to be trapped during the mixing of raw materials during production, which is thought to contribute to sufficient mechanical strength.

[0016] Hereinafter, the epoxy resin (A) component may be referred to as the "binder." In this case, when the layer material of the present invention contains the curing agent (D) component described below, the epoxy resin (A) component and the curing agent (D) component are collectively referred to as the "binder."

[0017] (Epoxy resin (A)) The epoxy resin from which the epoxy resin (A) contained in the layer material of the present invention is derived is not particularly limited as long as it is an epoxy resin having an epoxy equivalent of 140 or less. The lower limit of the epoxy equivalent of the epoxy resin (A) is not particularly limited, and is, for example, 60 or more, preferably 70 or more. The molecular weight of the epoxy resin (A) is not particularly limited and is, for example, 150 to 800, and preferably 200 to 700. The number of epoxy groups per molecule of the epoxy resin (A) is not particularly limited and may be, for example, 2 to 10, or 2 to 8. The epoxy resin (A) is preferably a compound represented by any one of the following general formulas (1) to (4), and the compound represented by general formula (1) is more preferred because rapid curing can increase both the sound velocity and acoustic impedance. Furthermore, the epoxy resin (A) preferably has an aromatic hydrocarbon ring from the viewpoint of high toughness of the acoustic matching layer material.

[0018] -Compound represented by general formula (1)- [ka]

[0019] In general formula (1), Cy 1 indicates a ring. 1a represents a linking group, and L 1b represents a linking group containing a nitrogen atom. 1 is 1 or 2, and q 1 is 1 or 2, and r 1 is an integer between 1 and 3.

[0020] Cy 1 may be a single ring or a condensed ring. Cy 1Examples of the ring include an alicyclic ring, an aliphatic heterocyclic ring, an aromatic hydrocarbon ring, and an aromatic heterocyclic ring, with an alicyclic ring and an aromatic hydrocarbon ring being preferred, and an aromatic hydrocarbon ring being more preferred. The number of ring-constituting carbon atoms of the alicyclic ring is not particularly limited and is, for example, 3 to 10, preferably 5 to 8, and more preferably 6. A specific example of the alicyclic ring is a cyclohexane ring. The number of ring-constituting atoms of the aliphatic heterocycle is not particularly limited and is, for example, 6 to 10, preferably 6. Examples of ring-constituting heteroatoms of the aromatic heterocycle include a nitrogen atom and an oxygen atom. The number of ring-constituting carbon atoms of the aromatic hydrocarbon ring is not particularly limited and is, for example, 6 to 10. Specific examples of the aromatic hydrocarbon ring include a benzene ring and a naphthalene ring. The number of ring-constituting atoms of the aromatic heterocycle is not particularly limited and is, for example, 6 to 10. Examples of the ring-constituting heteroatoms of the aromatic heterocycle include a nitrogen atom and an oxygen atom. A specific example of the aromatic heterocycle is a pyridine ring. Cy 1 may have a substituent, and specific examples of the substituent include an alkyl group (e.g., having 1 to 5 carbon atoms), an oxo group, an alkoxy group (e.g., having 1 to 5 carbon atoms), an amino group, an aryl group (e.g., a phenyl group and a naphthyl group), and a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom).

[0021] L 1a The linking group which can be taken by is preferably an alkylene group, an alkanetriyl group, a nitrogen atom, an oxygen atom, or a linking group containing a combination thereof. The alkylene group may be either linear or branched, and the number of carbon atoms in the alkylene group is, for example, 1 to 10, preferably 1 to 5, more preferably 1 or 2, and particularly preferably 1. Specific examples of the alkylene group include methylene, ethylene, propylene, and isopropylene. The alkanetriyl group may be either linear or branched, and the number of carbon atoms in the alkanetriyl group is, for example, 1 to 10, preferably 1 to 6, and more preferably 1 to 4. Specific examples of the alkanetriyl group include methanetriyl, ethanetriyl, and propanetriyl. Examples of the above-mentioned "linking group combining these" include a divalent linking group combining an alkylene group and an oxygen atom ("-alkylene-O-", "-O-alkylene-"), and a trivalent linking group combining an alkylene group and a nitrogen atom ("(-alkylene-)2nitrogen atom-", "-nitrogen atom(-alkylene-)2", "(-alkylene-)2nitrogen atom-alkylene-", "-alkylene-nitrogen atom(-alkylene-)2").

[0022] L 1b Examples of linking groups that can be taken by include divalent linking groups combining an imino group and an alkylene group ("-NH-alkylene group-", "-alkylene group-NH-"), and trivalent groups combining an alkylene group and a nitrogen atom ("(-alkylene-)2nitrogen atom-", "-nitrogen atom(-alkylene-)2", "(-alkylene-)2nitrogen atom-alkylene-", "-alkylene-nitrogen atom(-alkylene-)2"). A preferred form of the alkylene group is L 1a The alkylene group is the same as that described above.

[0023] Specific examples of the compound represented by general formula (1) are listed below, but the present invention is not limited to these. Below, "Mw" means molecular weight, and "EEW" means epoxy equivalent. The same applies to specific examples of the compound represented by any of general formulas (2) to (4) described later.

[0024] [ka]

[0025] -Compound represented by general formula (2)- [ka]

[0026] In general formula (2), Cy 2 indicates a ring. 2a and L 2b represents an alkylene group, an alkanetriyl group, an oxygen atom, or a linking group formed by combining these. 2 is 1 or 2, and q 2 is 1 or 2, and r 2 is an integer of 1 to 3 (preferably 1 or 2).

[0027] Cy 2 may be a single ring or a condensed ring. Cy 2 Examples of the ring include an alicyclic ring, an aliphatic heterocyclic ring, an aromatic hydrocarbon ring, and an aromatic heterocyclic ring, and an aromatic hydrocarbon ring is preferred. Cy 2 The alicyclic ring, aliphatic heterocyclic ring, aromatic hydrocarbon ring and aromatic heterocyclic ring that can be taken by the above "Cy 1 Examples of the alicyclic ring, the aliphatic heterocyclic ring, the aromatic hydrocarbon ring, and the aromatic heterocyclic ring described in the above section are alicyclic rings, aliphatic heterocyclic rings, aromatic hydrocarbon rings, and aromatic heterocyclic rings. Cy 2 may have a substituent, and specific examples of the substituent include those mentioned above in "Cy 1 " are examples of the substituents described above.

[0028] L 2a and L 2b The alkylene group may be either linear or branched, and the number of carbon atoms in the alkylene group is, for example, 1 to 10, preferably 1 to 5, more preferably 1 or 2, and particularly preferably 1. Specific examples of the alkylene group include methylene, ethylene, propylene, and isopropylene.

[0029] The alkanetriyl group may be either linear or branched, and the number of carbon atoms in the alkanetriyl group is, for example, 1 to 10, preferably 1 to 6, and more preferably 1 to 4. Specific examples of the alkanetriyl group include methanetriyl, ethanetriyl, and propanetriyl.

[0030] Examples of the above-mentioned "divalent or trivalent linking group formed by combining these" include divalent groups formed by combining an alkylene group with an oxygen atom ("-alkylene-O-", "-O-alkylene-").

[0031] Specific examples of the compound represented by formula (2) are listed below, but the present invention is not limited to these.

[0032] [ka]

[0033] -Compound represented by general formula (3)- [ka]

[0034] In general formula (3), Cy 3 indicates a ring. 3a represents a linking group containing a nitrogen atom, and L 3b represents a linking group. 3 represents a linking group. 3 is 1 or 2, and q 3 is 1 or 2, and r 3 is an integer of 0 to 3 (preferably 0 or 1), and s 3 is 2 or 3. However, the compound represented by general formula (3) has three or more epoxy groups.

[0035] Cy 3 may be a single ring or a condensed ring. Cy 3 Examples of the ring include an alicyclic ring, an aliphatic heterocyclic ring, an aromatic hydrocarbon ring, and an aromatic heterocyclic ring, and an aromatic hydrocarbon ring is preferred. Cy 3 The alicyclic ring, aliphatic heterocyclic ring, aromatic hydrocarbon ring and aromatic heterocyclic ring that can be taken by the above "Cy 1 Examples thereof include the alicyclic ring, the aliphatic heterocyclic ring, the aromatic hydrocarbon ring and the aromatic heterocyclic ring described in the above section, and the aromatic hydrocarbon ring is preferred. Cy 3may have a substituent, and specific examples of the substituent include those mentioned above in "Cy 1 " are examples of the substituents described above.

[0036] L 3a Examples of linking groups that can be taken by include trivalent groups that combine an alkylene group with a nitrogen atom ("(-alkylene-)2nitrogen atom-", "-nitrogen atom(-alkylene-)2").

[0037] L 3b The linking group which can be taken by is preferably an alkylene group, a nitrogen atom, an oxygen atom, or a linking group containing a combination thereof. The alkylene group may be either linear or branched, and the number of carbon atoms in the alkylene group is, for example, 1 to 10, preferably 1 to 5, more preferably 1 or 2, and particularly preferably 1. Specific examples of the alkylene group include methylene, ethylene, propylene, and isopropylene. Examples of the "linking group combining these" include a divalent linking group combining an alkylene group and an oxygen atom ("-alkylene-O-", "-O-alkylene-"), and a trivalent linking group combining an alkylene group and a nitrogen atom ("(-alkylene-)2nitrogen atom-", "-nitrogen atom(-alkylene-)2"). L 3b The linking group that can be taken by is preferably the above-mentioned "divalent linking group combining an alkylene group and an oxygen atom" and the above-mentioned "trivalent linking group combining an alkylene group and a nitrogen atom."

[0038] LL 3 Examples of the divalent linking group that can be taken by include an alkylene group and a sulfonyl group. The alkylene group may be either linear or branched, and the number of carbon atoms in the alkylene group is, for example, 1 to 10, preferably 1 to 5, more preferably 1 or 2, and particularly preferably 1. Specific examples of the alkylene group include methylene, ethylene, propylene, and isopropylene.

[0039] LL 3The trivalent linking group that can be taken by includes an alkanetriyl group. The alkanetriyl group may be either linear or branched, and the number of carbon atoms in the alkanetriyl group is, for example, 1 to 10, preferably 1 to 5, more preferably 1 or 2, and particularly preferably 1. Specific examples of the alkanetriyl group include methanetriyl, ethanetriyl, and propanetriyl.

[0040] Specific examples of the compound represented by formula (3) are listed below, but the present invention is not limited to these.

[0041] [ka]

[0042] -Compound represented by general formula (4)- [ka]

[0043] In general formula (4), Cy 4 indicates a ring. 4a and L 4b represents an alkylene group, an alkanetriyl group, an oxygen atom, or a linking group formed by combining these. 4 represents a linking group. 4 is 1 or 2, and q 4 is 1 or 2, and r 4 is an integer of 0 to 3 (preferably 1), and s 4 is 2 or 3 (preferably 2). However, the compound represented by general formula (4) has three or more epoxy groups.

[0044] Cy 4 may be a single ring or a condensed ring. Cy 4 Examples of the ring include an alicyclic ring, an aliphatic heterocyclic ring, an aromatic hydrocarbon ring, and an aromatic heterocyclic ring, and an aromatic hydrocarbon ring is preferred. Cy 4The alicyclic ring, aliphatic heterocyclic ring, aromatic hydrocarbon ring and aromatic heterocyclic ring that can be taken by the above "Cy 1 Examples thereof include the alicyclic ring, the aliphatic heterocyclic ring, the aromatic hydrocarbon ring and the aromatic heterocyclic ring described in the above section, and the aromatic hydrocarbon ring is preferred. Cy 4 may have a substituent, and specific examples of the substituent include those mentioned above in "Cy 1 " are examples of the substituents described above.

[0045] L 4a and L 4b The alkylene group may be either linear or branched, and the number of carbon atoms in the alkylene group is, for example, 1 to 10, or may be 1 to 5, or may be 1 or 2. Specific examples of the alkylene group include methylene, ethylene, propylene, and isopropylene.

[0046] The alkanetriyl group may be either linear or branched, and the number of carbon atoms in the alkanetriyl group is, for example, 1 to 10, or may be 1 to 6, or may be 1 to 4. Specific examples of the alkanetriyl group include methanetriyl, ethanetriyl, and propanetriyl.

[0047] Examples of the above-mentioned "linking group combining these" include a divalent group combining an alkylene group and an oxygen atom ("-alkylene-O-", "-O-alkylene-").

[0048] LL 4 Examples of the divalent linking group that can be taken by include an alkylene group. The alkylene group may be either linear or branched, and the number of carbon atoms in the alkylene group is, for example, 1 to 10, preferably 1 to 5, and more preferably 1 to 3. Specific examples of the alkylene group include methylene, ethylene, propylene, and 1-methylethylidene.

[0049] LL 4 The trivalent linking group that can be taken by includes an alkanetriyl group. The alkanetriyl group may be either linear or branched, and the number of carbon atoms in the alkanetriyl group is, for example, 1 to 10, preferably 1 to 5, more preferably 1 or 2, and particularly preferably 1. Specific examples of the alkanetriyl group include methanetriyl, ethanetriyl, and propanetriyl.

[0050] Specific examples of the compound represented by formula (4) are listed below, but the present invention is not limited to these.

[0051] [ka]

[0052] The epoxy resin (A) may be used alone or in combination of two or more.

[0053] In the layer material of the present invention, the epoxy resin (A) may be the epoxy resin (A) cured alone or may be the epoxy resin (A) cured by reaction with the curing agent (D) described below. In other words, the layer material of the present invention may contain a component derived from the curing agent (D).

[0054] (Metal particles (B)) The layer material of the present invention contains metal particles (B). By adjusting the content of these metal particles (B) in the layer material, the density of the layer material can be adjusted, and the acoustic impedance of the layer material can be adjusted to a desired level. The metal particles (B) may be surface-treated or not. This surface treatment can be performed, for example, with reference to WO 2019 / 088148.

[0055] The metal constituting the metal particles (B) has a density of 10 g / cm at 20°C. 3 Other than the above, there are no particular limitations. The metal particles (B) may be metal atoms alone, or may be metal carbides, nitrides, oxides, or borides. They may also form alloys. Examples of metals constituting the metal particles (B) include osmium, iridium, platinum, rhenium, neptunium, gold, tungsten, tantalum, hafnium, rhodium, ruthenium, palladium, thallium, lead, silver, molybdenum, etc. Among these, platinum, gold, tungsten, tantalum, hafnium, thallium, silver, molybdenum, and carbides thereof are preferred, tungsten, tantalum, hafnium, and carbides thereof are more preferred, tungsten and carbides thereof are even more preferred, and tungsten carbide is particularly preferred. There are no particular restrictions on the particle size of the metal particles (B). From the viewpoint of reducing the viscosity of the composition for an acoustic matching layer material and improving the mechanical strength of the acoustic matching layer material, the particle size of the metal particles (B) is, for example, preferably 0.01 to 100 μm, more preferably 1 to 10 μm, even more preferably 2 to 6 μm, and particularly preferably 2 to 4 μm.

[0056] The "particle size" of the metal particles (B) refers to the average primary particle size. Here, the average primary particle size is the volume-based median size, and is determined as follows. Metal particles (B) are added to methanol to a concentration of 0.5% by mass and dispersed by ultrasonication for 10 minutes. The particle size distribution of the treated metal particles (B) is measured using a laser diffraction / scattering particle size distribution analyzer (manufactured by Horiba, Ltd., product name: LA950V2), and the volume-based median diameter is determined. The median diameter corresponds to 50% of the cumulative particle size distribution when the particle size distribution is expressed as a cumulative distribution.

[0057] (Particle (C)) Particle (C) has a density of 4.5 g / cm 3 There are no particular limitations on the particle size as long as it is less than 1. As the particles (C), metal particles, ceramic particles, organic fine particles, silica particles and organic-inorganic composite particles can be used. Examples of metals that can be used to form the metal particles include barium, aluminum, boron, and oxides, nitrides, and carbides of these metals. The ceramic particles preferably contain at least one atom from groups 1 to 3 and 13 to 17 of the periodic table, and more preferably contain at least one (preferably one to three) of Mg, Ca, Ba, B, Al, Y, and Si, and at least one (preferably one) of O, C, N, and S. The ceramic particles are preferably carbides, nitrides, or oxides containing at least one (preferably 1 to 3) of Mg, Ba, B, Al, Y, and Si, and specific examples include magnesium-aluminum spinel (magnesium aluminate spinel, MgO·Al2O3), wollastonite (CaSiO3), cordierite (2MgO·2Al2O3·5SiO2), boron carbide (BC), silicon carbide (SiC), alumina (Al2O3), aluminum nitride (AlN), magnesium oxide (MgO), silicon nitride (Si3N4), boron nitride (BN), and yttrium oxide (YO3). As the organic fine particles, rubber particles, acrylic particles, melamine particles, carbon black, and graphite can be used. As the silica particles, fumed silica and fused silica can be used. As the organic-inorganic composite particles, silicone acrylic particles can be used. The particle size of the particles (C) is not particularly limited, but from the viewpoint of reducing the viscosity of the composition for an acoustic matching layer material and improving the mechanical strength of the acoustic matching layer material, the particle size of the particles (C) is, for example, preferably 0.01 to 100 μm, more preferably 1 to 10 μm, even more preferably 2 to 6 μm, and particularly preferably 2 to 4 μm. The "particle size" of the particles (C) is synonymous with the "particle size" of the metal particles (B).

[0058] (Curing agent (D)) The curing agent used in the present invention may be any of various curing agents commonly used as curing agents for epoxy resins. For example, an amine curing agent, an acid anhydride curing agent, a phenolic curing agent, an imidazole curing agent, a phosphine curing agent, a thiol curing agent, a Lewis acid curing agent, and dicyandiamide may be used. Among these, in terms of curing temperature and curing speed, it is preferable to use an amine curing agent, and it is particularly preferable to use an aromatic amine curing agent. It is also preferable to use a plurality of these curing agents, and it is also preferable to add a small amount of one of them as a curing aid. Specific examples of the curing agent (D) are shown below, but the present invention is not limited to these.

[0059] [ka]

[0060] In the layer material of the present invention, the contents of the binder, metal particles (B) and particles (C) are appropriately adjusted depending on the desired longitudinal wave sound velocity and acoustic impedance. The content of the binder in the layer material of the present invention is preferably 1 to 15 mass%, more preferably 1 to 11 mass%. The content of the metal particles (B) in the layer material of the present invention is preferably 80 to 98 mass%, more preferably 85 to 95 mass%, even more preferably 87 to 94 mass%, and particularly preferably 88 to 93 mass%. The content of the particles (C) in the layer material of the present invention is 5 mass% or less, more preferably 2 mass% or less, even more preferably less than 1 mass%, and particularly preferably 0.8 mass% or less.

[0061] The layer material of the present invention may be composed of a binder and metal particles (B), or a binder, metal particles (B), and particles (C). Furthermore, it may contain other components as long as the effects of the present invention are not impaired. Examples of components other than the binder, metal particles (B), and particles (C) (other components) include curing retarders, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, and thermal conductivity improvers. In the layer material of the present invention, the total content of the binder, metal particles (B) and particles (C) is preferably 80% by mass or more, more preferably 90% by mass or more.

[0062] The density of the layer material of the present invention at 25°C is, for example, 7.0 g / cm 3 or more, 7.2 g / cm 3 The density of the layer material of the present invention is usually 1.1×10 g / cm or more. 3 The following is the result. When the layer material of the present invention is formed into a sheet, the longitudinal wave acoustic velocity (m / sec) in the plane at 25° C. is preferably 2300 or more, more preferably 2400 or more, and particularly preferably 2500 or more. The longitudinal wave acoustic velocity is usually 2800 or less. Furthermore, when the layer material of the present invention is formed into a sheet, the in-plane acoustic impedance (Mrayl) at 25° C. is preferably 16 or more, more preferably 18 or more, and particularly preferably 22 or more. The acoustic impedance is usually 28 or less. The longitudinal wave velocity and acoustic impedance are determined according to the method described in the Examples below. Specifically, a layer material processed into a sheet is divided into three equal parts in the thickness direction, and the longitudinal wave velocity and acoustic impedance are measured at three independent locations on the middle sheet of the three obtained sheets. The thickness of the sheet does not substantially affect the longitudinal wave velocity and density.

[0063] <Composition for acoustic matching layer material> The composition for an acoustically matching layer material of the present invention (the composition used in the acoustically matching layer material of the present invention, hereinafter also referred to as "the composition of the present invention") contains an epoxy resin (A) and metal particles (B). The composition of the present invention may also contain particles (C), and the content of particles (C) in the solid content of the composition of the present invention is less than 5 mass %. Note that the solid content typically refers to components other than the solvent. The composition of the present invention may also contain the above-mentioned curing agent (D) and may also contain the above-mentioned other components.

[0064] When the composition of the present invention contains an epoxy resin (A) and a curing agent (D) as a binder, the curing reaction of the epoxy resin (A) may progress over time in the composition even under mild conditions. Therefore, the properties of this composition may change over time and become unstable. However, for example, by storing the composition at a temperature of −10° C. or below, the curing reaction can be prevented or sufficiently suppressed, resulting in a composition in which each component is maintained in a stable state. It is also preferable to use a resin composition containing an epoxy resin (A) and metal particles (B) as a base material, and to prepare an acoustic matching layer material set in which the base material and the curing agent (D) are separately separated. In preparing the acoustic matching layer material, the base material and the curing agent (D) are mixed to prepare the composition of the present invention, and this composition is then subjected to a curing reaction, thereby preparing the acoustic matching layer material. The mass ratio of the epoxy resin (A) and the curing agent (D) constituting the binder may be adjusted appropriately depending on the type of curing agent (D) used, etc. For example, the ratio of epoxy resin (A) / curing agent (D) may be 99 / 1 to 20 / 80, and preferably 90 / 10 to 40 / 60. Furthermore, when the composition of the present invention is used by mixing the main agent and the curing agent (D) during the preparation of the layer material using the above-mentioned acoustic matching layer material set, it is preferable to mix the main agent and the curing agent (D) so that the mass ratio of the epoxy resin (A) to the curing agent is epoxy resin (A) / curing agent (D) = 99 / 1 to 20 / 80, and it is more preferable to mix the main agent and the curing agent (D) so that the mass ratio is 90 / 10 to 40 / 60.

[0065] <Preparation of Composition for Acoustic Matching Layer Material> The acoustically matching layer composition of the present invention can be obtained, for example, by mixing the components constituting the acoustically matching layer composition. The mixing method is not particularly limited as long as it can mix the components substantially uniformly. For example, the desired uniform mixing can be achieved by kneading using a planetary centrifugal mixer.

[0066] Furthermore, when preparing an acoustic matching layer material set containing a base resin made of a resin composition containing an epoxy resin (A) and metal particles (B) and a curing agent (D) for this epoxy resin (A), the base resin can be obtained by mixing the epoxy resin (A) with the metal particles (B). During preparation of the acoustic matching layer material, the base resin and curing agent (D) are mixed to obtain the acoustic matching layer material composition of the present invention. By molding and curing this composition, the acoustic matching layer material or its precursor can be prepared.

[0067] [Acoustic matching sheet (acoustic matching layer)] The layer material of the present invention can be cut, diced, or otherwise processed to a desired thickness or shape as necessary to obtain an acoustic matching sheet. This acoustic matching sheet can also be further processed into a desired shape by conventional methods. Specifically, for example, the composition of the present invention is molded into a desired sheet shape at a low temperature range where a curing reaction does not occur or where the curing rate is sufficiently slow. Next, the molded product is cured by heating, etc., if necessary, to form a crosslinked structure, and then cut, diced, etc., to a desired thickness or shape, if necessary, to form an acoustic matching sheet or a precursor sheet thereof. In other words, the acoustic matching sheet formed is preferably a cured product formed by curing the composition of the present invention to form a three-dimensional network structure. This acoustic matching sheet is used as an acoustic matching layer for an acoustic wave probe. The configuration of an acoustic wave probe including an acoustic matching layer will be described later.

[0068] [Acoustic wave probe] The acoustic wave probe of the present invention has the acoustic matching sheet of the present invention as at least one layer of the acoustic matching layer. An example of the configuration of an acoustic wave probe of the present invention is shown in Fig. 1. The acoustic wave probe shown in Fig. 1 is an ultrasonic probe in an ultrasonic diagnostic device. Note that an ultrasonic probe is a probe that uses ultrasonic waves as the acoustic wave in the acoustic wave probe. Therefore, the basic structure of an ultrasonic probe can be applied directly to an acoustic wave probe.

[0069] <Ultrasonic probe> The ultrasonic probe 10 is a main component of an ultrasonic diagnostic device, and has the functions of generating ultrasonic waves and transmitting and receiving ultrasonic beams. As shown in Figure 1, the ultrasonic probe 10 is configured with an acoustic lens 1, an acoustic matching layer 2, a piezoelectric element layer 3, and a backing material 4, arranged in this order from the tip (the surface that comes into contact with the living body being examined). In recent years, a laminated structure has been proposed in which the transmitting ultrasonic transducer (piezoelectric element) and the receiving ultrasonic transducer (piezoelectric element) are made of different materials, with the aim of receiving higher-order harmonics.

[0070] (Piezoelectric element layer) The piezoelectric element layer 3 is the part that generates ultrasonic waves, and has electrodes attached to both sides of the piezoelectric element. When a voltage is applied, the piezoelectric element vibrates by repeatedly expanding and contracting, thereby generating ultrasonic waves.

[0071] Materials that make up piezoelectric elements include inorganic ceramic piezoelectrics, such as single crystals such as quartz, LiNbO3, LiTaO3, and KNbO3, thin films such as ZnO and AlN, and polarized sintered bodies such as Pb(Zr,Ti)O3. Generally, piezoelectric ceramics such as PZT (lead zirconate titanate) are used, which have good conversion efficiency. Furthermore, piezoelectric elements that detect received high-frequency waves require sensitivity over a wider bandwidth. For this reason, organic piezoelectric materials made from organic polymers such as polyvinylidene fluoride (PVDF) are used as piezoelectric elements suitable for high frequencies and wide bandwidths. Furthermore, Japanese Patent Application Laid-Open No. 2011-071842 and the like describe a cMUT that utilizes MEMS (Micro Electro Mechanical Systems) technology, which exhibits excellent short pulse characteristics and wideband characteristics, is suitable for mass production, and provides an array structure with little characteristic variation. In the present invention, any of the piezoelectric element materials can be preferably used.

[0072] (backing material) The backing material 4 is provided on the back surface of the piezoelectric element layer 3, and reduces the pulse width of the ultrasonic waves by suppressing excess vibrations, thereby contributing to improving the distance resolution in ultrasonic diagnostic images.

[0073] (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 to be examined, and to efficiently transmit and receive ultrasonic waves.

[0074] (acoustic lens) The acoustic lens 1 is provided to improve resolution by focusing ultrasonic waves in the slice direction using refraction. It is also required to be in close contact with the living body being examined, to match the ultrasonic waves with the acoustic impedance of the living body (1.4 to 1.7 Mrayl for the human body), and to have low ultrasonic attenuation of the acoustic lens 1 itself. In other words, by using a material for the acoustic lens 1 whose longitudinal wave sound velocity is sufficiently smaller than that of the human body, whose ultrasonic attenuation is small, and whose acoustic impedance is close to that of human skin, the ultrasonic transmission and reception sensitivity can be increased.

[0075] The operation of the ultrasonic probe 10 configured as described above will be explained below. A voltage is applied to the electrodes provided on both sides of the piezoelectric element to resonate the piezoelectric element layer 3, and an ultrasonic signal is transmitted to the subject through the acoustic lens. During reception, the piezoelectric element layer 3 is vibrated by a reflected signal (echo signal) from the subject, and this vibration is converted electrically into a signal to obtain an image.

[0076] [Manufacturing of acoustic wave probes] The acoustic wave probe of the present invention can be produced by a conventional method except for using the acoustic matching sheet of the present invention. That is, the method for producing the acoustic wave probe of the present invention includes forming an acoustic matching layer on a piezoelectric element using the acoustic matching sheet of the present invention. The piezoelectric element can be provided on a backing material by a conventional method. Furthermore, an acoustic lens is formed on the acoustic matching layer by a conventional method using an acoustic lens forming material.

[0077] [Acoustic wave measuring device] An acoustic wave measurement device of the present invention includes the acoustic wave probe of the present invention, and has the function of displaying the signal intensity of a signal received by the acoustic wave probe and imaging the signal. The acoustic wave measuring device of the present invention is also preferably an ultrasonic wave measuring device using an ultrasonic probe. [Example]

[0078] The present invention will be described in more detail based on examples in which ultrasonic waves are used as acoustic waves, but the present invention is not limited by the examples except as defined in the present invention. In the following, the blending amount of a component means the blending amount of the component itself. In other words, if the raw material contains a solvent, the amount is the amount excluding the solvent. In the present invention, the acoustic wave is not limited to ultrasonic waves, and an acoustic wave of an audio frequency may be used as long as an appropriate frequency is selected depending on the test object, measurement conditions, etc. Hereinafter, room temperature means 25°C.

[0079] [Synthesis example] <1> Preparation of composition for acoustic matching layer material (1) Preparation of the Acoustic Matching Layer Material Composition Used in Example 1 A composition for an acoustic matching layer material having the composition shown in Table 1-1 was prepared. Specifically, 116 parts by mass of tungsten carbide particles (WC-60S (particle size: 6 μm) (trade name, manufactured by A.L.M.T. Corporation)), 10 parts by mass of epoxy resin (1-3) (Sumitomo Chemical Co., Ltd.'s "Sumiepoxy ELM-120" (trade name), epoxy equivalent 92)), and 2.9 parts by mass of curing agent (2) (metaphenylenediamine, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed using a rotation-revolution device (trade name: ARV-310, manufactured by Thinky Corporation) to prepare the composition for the acoustic matching layer material used in Example 1.

[0080] (2) Preparation of Acoustic Matching Layer Compositions Used in Examples 2 to 31 and Comparative Examples 1 to 4 The compositions for acoustic matching layer materials used in Examples 2 to 31 and Comparative Examples 1 to 4 were prepared in the same manner as the composition for acoustic matching layer materials used in Example 1, except that the compositions were changed to those shown in Tables 1-1 to 1-3 below (hereinafter, Tables 1-1 to 1-3 are collectively referred to as Table 1).

[0081] <2> Fabrication of acoustic matching sheets (sheet-shaped acoustic matching layer materials) (1) Preparation of the acoustic matching sheet of Example 1 The acoustic matching layer composition used in Example 1 was poured into a circular mold 40 mm in diameter and 3 mm deep, and cured at 80° C. for 18 hours and then at 150° C. for 1 hour to produce a circular sheet-shaped acoustic matching layer material 40 mm in diameter and 3 mm thick. This sheet was cut with a dicer into three circular acoustic matching sheets 40 mm in diameter and 1 mm thick, and the middle acoustic matching sheet (1 mm thick) was used for the measurements described below.

[0082] (2) Preparation of Acoustic Matching Sheets of Examples 2 to 31 and Comparative Examples 1 to 4 An acoustic matching sheet (thickness 1 mm) (the middle one of the three acoustic matching sheets cut into pieces) was prepared in the same manner as the acoustic matching sheet of Example 1, except that the acoustic matching layer composition used in Examples 2 to 31 and Comparative Examples 1 to 4 was used instead of the acoustic matching layer composition used in Example 1, and used in the measurements below.

[0083] [Test Example 1] Measurement of longitudinal wave sound velocity The ultrasonic longitudinal wave sound velocity was measured at 25°C using a singe-around sound velocity measuring device (manufactured by Ultrasonic Industries, product name "UVM-2 type") in accordance with JIS Z2353 (2003). For the circular acoustic matching sheet obtained above, with a diameter of 40 mm and a thickness of 1 mm, three circular regions with a diameter of 15 mm that did not overlap each other were measured, and the entire interior of these three circular regions (single-channel small probe size) was measured. The arithmetic mean value of the longitudinal wave sound velocity for the three circular regions was calculated and evaluated according to the following evaluation criteria. A to C are acceptable for this test. D makes it difficult to achieve the desired high acoustic impedance envisioned by the present invention. -Evaluation criteria- A:2500[m / sec] or more B: 2400 [m / sec] or more, less than 2500 [m / sec] C: 2300 [m / sec] or more, less than 2400 [m / sec] D: Less than 2300 [m / sec]

[0084] [Test Example 2] Density measurement and acoustic impedance calculation For the circular acoustic matching sheet obtained above, with a diameter of 40 mm and a thickness of 1 mm, a 9 mm x 9 mm test piece was cut out from each of the three circular regions where the longitudinal wave sound velocity was measured. The density of each cut-out sample at 25°C was measured using an electronic hydrometer (manufactured by Alpha Mirage, product name "SD-200L") in accordance with the density measurement method A (underwater displacement method) described in JIS K7112 (1999), and the arithmetic mean value of the densities of the three circular regions was obtained. The acoustic impedance was calculated from the product of the thus obtained density and the longitudinal wave sound velocity (arithmetic mean value of density x arithmetic mean value of longitudinal wave sound velocity) and evaluated according to the following evaluation criteria. A, B, and C indicate passing the test. -Evaluation criteria- A: 22Mrayl or more B: 18Mrayl or more, less than 22Mrayl C: 16Mrayl or more, less than 18Mrayl D: Less than 16 Mrayl

[0085] [Test Example 3] Presence or absence of air bubbles The cross section of each side of the 9 mm x 9 mm test piece used in Test Example 2 was observed under an optical microscope at 200x magnification, and the number of bubbles was counted. The average number of bubbles on all four sides was calculated and evaluated according to the following evaluation criteria. A, B, and C indicate passing the test. -Evaluation criteria- A: No bubbles. B: 1 to 3 bubbles C: 4 to 10 bubbles D: 11 or more bubbles

[0086] [Test Example 4] Tensile test The acoustic matching sheet (1 mm thick) prepared above was measured at room temperature using a Tensilon universal material testing machine (product name: RTF-1210, manufactured by A&D Co., Ltd.). A, B, and C are pass marks for this test. -Evaluation criteria- A: Tensile strength is 30 MPa or more B: Tensile strength is 20 MPa or more and less than 30 MPa C: Tensile strength is 10 MPa or more and less than 20 MPa D: Tensile strength less than 10 MPa

[0087] [Table 1-1]

[0088] [Table 1-2]

[0089] [Table 1-3]

[0090] Top row 1-31: Examples 1-31 Top row c1 to c4: Comparative examples c1 to c4

[0091] [Epoxy resin (A)] -Epoxy resin (A) used in the examples- (1-3), (1-5), (1-6), (1-13), (2-1), (2-2), (2-5), (2-7), (3-2), (4-4) and (4-5): the above-mentioned exemplary compounds (1-3), (1-5), (1-6), (1-13), (2-1), (2-2), (2-5), (2-7), (3-2), (4-4) and (4-5)

[0092] (5-1): The following compound [ka]

[0093] -Epoxy resin used in comparative examples- X-1: The following compound [ka]

[0094] X-2: The following compound [ka] In addition, X-1 and X-2 are listed in the column of epoxy resin (A) to facilitate comparison between the examples and comparative examples.

[0095] [Hardening agent (D)] (1), (2), (4), (8), (12), (13), and (14): the above-mentioned exemplary compounds (1), (2), (4), (8), (12), (13), and (14).

[0096] [Metal particles (B)] WC (particle size 10 μm): tungsten carbide particles (WC-100S (product name) manufactured by A.L.M.T. Corporation) WC (particle size 6 μm): tungsten carbide particles (WC-60S (product name) manufactured by A.L.M.T. Corporation) WC (particle size 2.5 μm): tungsten carbide particles (WC-25S (product name) manufactured by A.L.M.T. Corporation) WC (particle size 1 μm): tungsten carbide particles (A.L.M.T. Corporation, W-U010 (product name)) W (particle size 6 μm): tungsten particles (D-20 (product name) manufactured by A.L.M.T. Corp.) TaC (particle size 3 μm): Tantalum carbide particles (manufactured by Nippon Shinkinzoku Co., Ltd.) Mo (particle size 6 μm): molybdenum particles (TMO-50 (product name) manufactured by A.L.M.T. Corporation) Fe (particle size 5 μm): Iron particles (iron powder) (manufactured by Kojundo Chemical Laboratory Co., Ltd.)

[0097] [Particle (C)] SiC (particle size 3 μm): silicon carbide particles (manufactured by Kojundo Chemical Laboratory Co., Ltd.) Al2O3 (particle size 3 μm): alumina particles (N-9000 (product name) manufactured by Nishimura Porcelain Co., Ltd.) SiO2 (particle size 3 μm): Silica particles (manufactured by Corefront)

[0098] Table 1 reveals the following: The acoustic matching sheets of Comparative Examples 1 and 2, which were made using an epoxy resin with an epoxy equivalent of more than 140 and metal particles (B), failed Test Example 2 (acoustic impedance). 3 The acoustic matching sheet of Comparative Example 3, which was produced using metal particles of less than 1000 nm, failed Test Example 2 (acoustic impedance). The acoustic matching sheet of Comparative Example 4 uses epoxy resin (A) and metal particles (B), but because the content of particles (C) exceeded 5 mass %, numerous air bubbles were generated and sufficient mechanical strength was not obtained. In contrast, the acoustic matching sheets of Examples 1 to 31 of the present invention contain a small amount of bubbles, have sufficient mechanical strength, and furthermore, exhibit a high longitudinal wave speed and a high acoustic impedance in a thin film state.

[0099] While the present invention has been described in connection with embodiments thereof, we do not intend to limit our invention to any of the details of the description unless otherwise specified, and believe that the claims should be construed broadly without departing from the spirit and scope of the invention as set forth in the appended claims.

[0100] This application claims priority based on Japanese Patent Application No. 2021-161984, filed in Japan on September 30, 2021, the contents of which are incorporated herein by reference as part of the present specification. [Explanation of symbols]

[0101] 1 Acoustic Lens 2 Acoustic matching layer 3 Piezoelectric element layer 4 Backing material 7. Housing 9 Chords 10 Ultrasonic probe

Claims

1. An epoxy resin (A) component having an epoxy equivalent of 140 or less and a density at 20°C of 10 g / cm ３ and the above metal particles (B), and the density at 20°C is 4.5 g / cm ３ The acoustic matching layer material has a content of particles (C) of less than 5 mass %.

2. 2. The acoustic matching layer material according to claim 1, wherein the epoxy resin (A) component is a component derived from a compound represented by any one of the following general formulas (1) to (4): 【Chemistry 1】 In general formula (1), Cy １ represents a ring. １ａ represents a linking group, and L １ｂ represents a linking group containing a nitrogen atom. １ is 1 or 2, and q １ is 1 or 2, and r １ is an integer from 1 to 3. 【Chemistry 2】 In general formula (2), Cy ２ represents a ring. ２ａ and L ２ｂ represents an alkylene group, an alkanetriyl group, an oxygen atom, or a linking group formed by combining these. ２ is 1 or 2, and q ２ is 1 or 2, and r ２ is an integer from 1 to 3. 【Transformation 3】 In general formula (3), Cy ３ represents a ring. ３ａ represents a linking group containing a nitrogen atom, and L ３ｂ represents a linking group. ３ represents a linking group. ３ is 1 or 2, and q ３ is 1 or 2, and r ３ is an integer from 0 to 3, and s ３ is 2 or 3. However, the compound represented by the general formula (3) has three or more epoxy groups. 【Chemistry 4】 In general formula (4), Cy ４ represents a ring. ４ａ and L ４ｂ represents an alkylene group, an alkanetriyl group, an oxygen atom, or a linking group formed by combining these. ４ represents a linking group. ４ is 1 or 2, and q ４ is 1 or 2, and r ４ is an integer from 0 to 3, and s ４ is 2 or 3. However, the compound represented by the general formula (4) has three or more epoxy groups.

3. 3. The acoustic matching layer material according to claim 1, wherein the acoustic matching layer material contains a curing agent (D) component, and the curing agent (D) contains an amine curing agent.

4. 4. The acoustic matching layer material according to claim 3, wherein the amine curing agent comprises an aromatic amine.

5. 3. The acoustic matching layer material according to claim 1, wherein the epoxy resin component (A) has an aromatic hydrocarbon ring.

6. Density at 25°C is 7.0 g / cm ３ 3. The acoustic matching layer material according to claim 1 or 2, wherein:

7. 3. The acoustic matching layer material according to claim 1, wherein the longitudinal wave velocity of ultrasonic waves at 25[deg.] C. is 2300 m / sec or more.

8. 3. The acoustic matching layer material according to claim 1, wherein the acoustic impedance at 25°C is 16 Mrayl or more.

9. An acoustic matching sheet comprising the acoustic matching layer material according to claim 1 or 2.

10. An epoxy resin (A) component having an epoxy equivalent of 140 or less and a density at 20°C of 10 g / cm ３ and the above metal particles (B), and the density at 20°C is 4.5 g / cm ３ 3. The composition for an acoustic matching layer material for obtaining the acoustic matching layer material according to claim 1 or 2, wherein the content of the particles (C) of less than 10 ...

11. An acoustic wave probe having the acoustic matching sheet according to claim 9 as an acoustic matching layer.

12. An acoustic wave measuring device comprising the acoustic wave probe according to claim 11.

13. The acoustic wave measuring device according to claim 12 , wherein the acoustic wave measuring device is an ultrasonic diagnostic device.

14. 3. A method for manufacturing an acoustic wave probe, comprising forming an acoustic matching layer on a piezoelectric element using the acoustic matching layer material according to claim 1.

Images