Material for acoustic matching layer, acoustic matching sheet, acoustic wave probe, ultrasonic probe, acoustic wave measuring device, ultrasonic diagnostic device, and method for manufacturing acoustic wave probe

Abstract

The present invention provides an acoustic matching layer material, an acoustic matching sheet, an acoustic wave probe, an ultrasonic probe, an acoustic wave measuring device, an ultrasonic diagnostic device, and a method for manufacturing an acoustic wave probe. The acoustic matching layer material utilizes high-density tungsten carbide particles as a metal filler, effectively improving the acoustic impedance of the acoustic matching sheet by suppressing the decrease in sound velocity caused by the inclusion of the tungsten carbide particles, and also suppressing changes in acoustic properties within the acoustic matching sheet. The acoustic matching layer material contains the following components (A), (B), and (C): (A) an epoxy resin; (B) a curing agent; and (C) surface-treated tungsten carbide particles treated with a surface treatment agent comprising at least one of an aminosilane compound, a mercaptosilane compound, an isocyanatosilane compound, a thiocyanatosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound.

Description

Technical Field

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

[0002] As an acoustic wave measuring device, an acoustic wave probe is used. This probe irradiates an object, such as a living organism, with acoustic waves, receives reflected waves (echoes), and outputs a signal. The reflected waves received by the acoustic wave probe are converted into electrical signals and displayed as images. Therefore, the use of an acoustic wave probe allows visualization and observation of the interior of the object being examined.

[0003] As the acoustic wave, ultrasonic waves, photoacoustic waves, or the like are appropriately selected depending on the object to be examined or the measurement conditions.

[0004] For example, an ultrasonic diagnostic apparatus, which is a type of acoustic wave measuring apparatus, transmits ultrasonic waves into the interior of an object to be examined, receives the ultrasonic waves reflected by tissues inside the object to be examined, and displays the received ultrasonic waves as an image.

[0005] Furthermore, photoacoustic wave measurement devices, a type of acoustic wave measurement device, receive acoustic waves emitted from within the subject through the photoacoustic effect and display them as images. The photoacoustic effect is a phenomenon in which, when electromagnetic wave pulses, such as visible light, near-infrared light, or microwaves, are irradiated onto the subject, the subject absorbs the electromagnetic waves, generates heat, and undergoes thermal expansion, generating acoustic waves (typically ultrasonic waves).

[0006] Because an acoustic wave measuring device transmits and receives sound waves to and from the object being examined, the acoustic wave probe must match the acoustic impedance of the object being examined (typically the human body). To meet this requirement, the acoustic wave probe is equipped with an acoustic matching layer. This will be explained using an ultrasonic diagnostic probe (also called an ultrasound probe), a type of acoustic wave probe, as an example.

[0007] An ultrasonic probe consists of a piezoelectric element that transmits and receives ultrasonic waves and an acoustic lens that contacts the living organism. An acoustic matching layer is placed between the piezoelectric element and the acoustic lens. Ultrasonic waves oscillating from the piezoelectric element pass through the acoustic matching layer and further through the acoustic lens before entering the living organism. There is typically a difference in acoustic impedance (density x sound velocity) between the acoustic lens and the living organism. A large difference in acoustic impedance makes ultrasonic waves more likely to reflect off the surface of the living organism, reducing the efficiency of ultrasonic waves entering the living organism. Therefore, the acoustic lens is required to have acoustic impedance characteristics close to those of the living organism.

[0008] On the other hand, the difference in acoustic impedance between the piezoelectric element and the living organism is typically large. Consequently, the difference in acoustic impedance between the piezoelectric element and the acoustic lens is also typically large. Consequently, in the case of a stacked structure of a piezoelectric element and an acoustic lens, the ultrasonic waves oscillating from the piezoelectric element reflect off the surface of the acoustic lens, reducing the efficiency of ultrasonic waves entering the living organism. To suppress this reflection of ultrasonic waves, 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 organism or the acoustic lens and the acoustic impedance of the piezoelectric element, thereby improving the efficiency of ultrasonic waves propagating from the piezoelectric element to the living organism. Furthermore, in recent years, the development of acoustic matching layers has been underway: these layers are formed into a multilayer structure composed of multiple stacked acoustic matching sheets (sheet-shaped acoustic matching layer materials), tilting the acoustic impedance from the piezoelectric element side toward the acoustic lens side, thereby further improving the efficiency of ultrasonic waves propagating.

[0009] The acoustic impedance of the acoustic matching layer can be adjusted by adding fillers such as metal particles to the acoustic matching layer forming material. For example, Patent Document 1 describes a resin composition for an acoustic matching layer comprising: a binder including a resin such as an epoxy resin; and surface-treated metal particles.

[0010] Previous technical literature

[0011] Patent Literature

[0012] Patent Document 1: International Publication No. 2019 / 088148 Summary of the Invention

[0013] Technical issues to be solved by the invention

[0014] In a multi-layered acoustic matching layer, the acoustic impedance gradient is designed so that the closer the sheet is to the piezoelectric element, the greater its acoustic impedance becomes, and the closer it is to the acoustic lens, the smaller its acoustic impedance becomes. Specifically, the acoustic matching sheet is required to have an acoustic impedance close to that of the piezoelectric element (typically around 25 Mrayl) on the piezoelectric element side, and close to that of the living organism (1.4-1.7 Mrayl in the human body) on the acoustic lens side.

[0015] The acoustic impedance of an acoustic matching sheet is determined by multiplying the density of the sheet's constituent material by the velocity of sound. Therefore, when attempting to increase the acoustic impedance of an acoustic matching sheet for use on the piezoelectric element side, one may consider using a material with both a high density and a high velocity of sound. However, it is known that if a filler such as a metal with a high specific gravity is included in an acoustic matching sheet in order to increase the acoustic impedance, while the density of the sheet can be increased, the velocity of sound of the sheet will decrease. Therefore, when a filler such as a metal with a high specific gravity is used in an acoustic matching sheet, if the sheet is to be used on the piezoelectric element side, it is necessary to suppress the aforementioned decrease in velocity of sound. However, Patent Document 1 does not describe this point.

[0016] An object of the present invention is to provide an acoustic matching layer material that uses high-specific-density tungsten carbide particles as a metal filler, effectively improves the acoustic impedance of an acoustic matching sheet by suppressing a decrease in sound velocity due to the inclusion of the tungsten carbide particles, and also suppresses changes in acoustic characteristics within the acoustic matching sheet.

[0017] Another object of the present invention is to provide an acoustic matching sheet that uses tungsten carbide particles as a metal filler, suppresses the decrease in sound velocity caused by the incorporation of the tungsten carbide particles, effectively improves acoustic impedance, and minimizes variations in acoustic characteristics within the sheet.

[0018] Furthermore, another object of the present invention is to provide an acoustic wave probe and an ultrasonic probe using the acoustic matching sheet, and an acoustic wave measuring device and an ultrasonic diagnostic device using the same.

[0019] Furthermore, another object of the present invention is to provide a method for manufacturing an acoustic wave probe using the acoustic matching layer material.

[0020] Means for solving technical problems

[0021] The present inventors conducted intensive research on the above-mentioned issues and discovered that by curing an epoxy resin and a curing agent in the presence of tungsten carbide particles treated with a specific surface treatment agent to produce an acoustic matching sheet, the decrease in sound velocity typically associated with the inclusion of tungsten carbide particles can be suppressed, and changes in the acoustic properties of the acoustic matching sheet can be minimized. The present invention was completed based on these findings.

[0022] That is, the above-mentioned problems of the present invention are solved by the following means.

[0023] <1>

[0024] A material for an acoustic matching layer, comprising the following components (A), (B) and (C),

[0025] (A) Epoxy resin

[0026] (B) Curing agent

[0027] (C) Surface-treated tungsten carbide particles surface-treated with a surface treatment agent comprising at least one of an aminosilane compound, a mercaptosilane compound, an isocyanatosilane compound, a thiocyanatosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound.

[0028] <2>

[0029] The acoustic matching layer material according to <1>, wherein the component (B) contains at least one of a primary amine and a secondary amine.

[0030] <3>

[0031] The acoustic matching layer material according to <1> or <2>, wherein the surface treatment agent includes at least one of an aminosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound.

[0032] <4>

[0033] The acoustic matching layer material according to any one of <1> to <3>, wherein the surface treatment agent includes at least one of an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound.

[0034] <5>

[0035] The acoustic matching layer material according to any one of <1> to <4>, wherein the surface treatment agent includes at least one of a zirconium alkoxide compound and a titanium alkoxide compound.

[0036] <6>

[0037] The acoustic matching layer material according to any one of <1> to <5>, wherein the zirconium alkoxide compound contains at least one of an acetonate structure and an acetate structure.

[0038] <7>

[0039] The acoustic matching layer material according to any one of <1> to <6>, wherein the aluminum alkoxide compound includes at least one compound represented by the following general formula (1).

[0040] General formula (1): R 1a m1 -Al-(OR 2a ) 3-m1

[0041] R 1a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group or an unsaturated aliphatic group,

[0042] R 2a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group or -SO2R S1 , R S1 represents a substituent,

[0043] m1 is an integer from 0 to 2.

[0044] <8>

[0045] The acoustic matching layer material according to any one of <1> to <7>, wherein the zirconium alkoxide compound contains at least one of an acetonate structure and an acetate structure.

[0046] <9>

[0047] The acoustic matching layer material according to any one of <1> to <8>, wherein the zirconium alkoxide compound includes at least one compound represented by the following general formula (2).

[0048] General formula (2): R 1b m2 -Zr-(OR 2b ) 4-m2

[0049] R 1b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group or an unsaturated aliphatic group,

[0050] R 2b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group or -SO2R S2 , R S2 represents a substituent,

[0051] m2 is an integer from 0 to 3.

[0052] <10>

[0053] The acoustic matching layer material according to any one of <1> to <9>, wherein the titanium alkoxide compound contains at least one atom of N, P, and S.

[0054] <11>

[0055] The acoustic matching layer material according to any one of <1> to <10>, wherein the titanium alkoxide compound includes at least one compound represented by the following general formula (3).

[0056] General formula (3): R 1c m3 -Ti-(OR 2c ) 4-m3

[0057] R 1c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group or an unsaturated aliphatic group,

[0058] R 2c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group or -SO2R S3 , R S3 represents a substituent,

[0059] m3 is an integer from 0 to 3.

[0060] <12>

[0061] The acoustic matching layer material according to any one of <1> to <11>, wherein the content of the surface treatment agent in the component (C) is 1 to 50 parts by mass based on 100 parts by mass of the tungsten carbide particles.

[0062] <13>

[0063] The acoustic matching layer material according to any one of <1> to <12>, wherein the tungsten carbide particles constituting the component (C) have an average primary particle size of 1 to 10 μm.

[0064] <14>

[0065] An acoustic matching sheet obtained by curing the acoustic matching layer material according to any one of <1> to <13>.

[0066] <15>

[0067] An acoustic wave probe comprising the acoustic matching sheet described in <14>.

[0068] <16>

[0069] An ultrasonic probe comprising the acoustic matching sheet described in <14>.

[0070] <17>

[0071] An acoustic wave measuring device comprises the acoustic wave probe described in <15>.

[0072] <18>

[0073] An ultrasonic diagnostic apparatus includes the ultrasonic probe described in <16>.

[0074] <19>

[0075] A method for manufacturing an acoustic wave probe, comprising the step of forming an acoustic matching layer using the acoustic matching layer material described in any one of <1> to <13>.

[0076] In this specification, a "metal alkoxide compound (specifically, for example, the titanium alkoxide compounds, aluminum alkoxide compounds, and zirconium alkoxide compounds described below)" refers to a compound having a structure in which at least one alkoxy group is bonded to a metal atom. The alkoxy group may have a substituent. The substituent may be monovalent or divalent (for example, an alkylene group). Furthermore, two alkoxy groups bonded to a single metal atom may bond to each other to form a ring.

[0077] In the present specification, unless otherwise specified, when there are multiple groups with the same symbol in a general formula representing a compound, they may be the same or different. Furthermore, the group represented by each group (e.g., an alkyl group) may further have a substituent.

[0078] Furthermore, in this specification, “to” is used to mean that the numerical values described before and after it are included as the lower limit and the upper limit.

[0079] Effects of the Invention

[0080] The acoustic matching layer material of the present invention uses tungsten carbide particles with a high specific gravity as a metal filler. This effectively improves the acoustic impedance of the acoustic matching sheet by suppressing the decrease in sound velocity due to the inclusion of the tungsten carbide particles, and also suppresses changes in acoustic characteristics within the acoustic matching sheet.

[0081] Furthermore, the acoustic matching sheet of the present invention uses tungsten carbide particles as a metal filler. This effectively improves acoustic impedance by suppressing a decrease in acoustic velocity due to the incorporation of the tungsten carbide particles, and also minimizes variations in acoustic characteristics within the sheet.

[0082] Furthermore, the acoustic wave probe, ultrasonic probe, acoustic wave measuring device, and ultrasonic diagnostic device of the present invention include an acoustic matching sheet having the above-mentioned excellent characteristics.

[0083] Furthermore, according to the method for manufacturing an acoustic wave probe of the present invention, an acoustic wave probe using the above-mentioned acoustic matching layer material can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 This is a perspective view of an example of a convex ultrasonic probe, which is one form of an acoustic wave probe. DETAILED DESCRIPTION

[0085] <<Materials for Acoustic Matching Layer>>

[0086] The acoustic matching layer material of the present invention (hereinafter also simply referred to as "material") contains the following components (A), (B), and (C).

[0087] (A) Epoxy resin

[0088] (B) Curing agent

[0089] (C) Surface-treated tungsten carbide particles surface-treated with at least one surface treatment agent selected from the group consisting of aminosilane compounds, mercaptosilane compounds, isocyanatosilane compounds, thiocyanatosilane compounds, aluminum alkoxide compounds, zirconium alkoxide compounds, and titanium alkoxide compounds.

[0090] The material of the present invention includes a composition obtained by mixing the above-mentioned components (A) to (C). When the material of the present invention is in the form of a composition for an acoustic matching layer (hereinafter also referred to as the "composition" of the present invention), that is, when the above-mentioned components (A) to (C) are contained in a container in a mixed state, the composition is preferably stored at -10°C or below to prevent the reaction of the above-mentioned components (A) to (C) or to sufficiently suppress the reaction so that the components are stably maintained.

[0091] The material of the present invention includes a kit for an acoustic matching layer (hereinafter also referred to as the "kit" of the present invention) in a state where the material is separated into the above-mentioned components (A) to (C) and contained in a container. Examples of such a kit include the following aspects (i) to (iv).

[0092] (i) containing the above-mentioned components (A) and (B); and the above-mentioned component (C), which are mixed and used when used,

[0093] (ii) containing the above-mentioned components (A) and (C); and the above-mentioned component (B), which are mixed when used,

[0094] (iii) containing the above-mentioned component (A); and the above-mentioned components (B) and (C), which are mixed and used when used, and

[0095] (iv) A form in which the above components (A) to (C) are separately contained and mixed for use

[0096] In the above-mentioned aspects (i) to (iv), in order to keep the components stably maintained, the kit of the present invention is preferably stored at -10°C or lower.

[0097] Furthermore, the material of the present invention can be stored in a light-shielding manner as needed.

[0098] If the acoustic matching sheet contains a filler with a high specific gravity, the acoustic velocity of the sheet will decrease. This is presumably because the inertia of the sound wave (mainly the longitudinal wave) when penetrating the acoustic matching sheet causes a phase delay at the filler interface, resulting in a decrease in the acoustic velocity. However, the acoustic matching sheet of the present invention obtained by curing the material of the present invention having the above structure (sound velocity = (sheet elastic modulus / sheet density) 1 / 2 ) is suppressed, and the acoustic properties show little change. The reasons for this are unclear, but can be speculated as follows. It is believed that the main reason is that in the acoustic matching sheet of the present invention, component (C) is surface-treated with a specific surface treatment agent, forming a structure at the interface between component (C) and the matrix resin that helps improve the elastic modulus of the sheet. This, in turn, suppresses the aggregation of component (C) while slightly agglomerating trace amounts of component (C) together, thereby improving the elastic modulus.

[0099] <(A) Epoxy resin>

[0100] As the epoxy resin used in the present invention, a common epoxy resin can be used, and for example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a phenol novolac type epoxy resin are preferred.

[0101] The bisphenol A epoxy resin that can be used in the present invention is not particularly limited, and a wide range of resins commonly used as the main agent of epoxy adhesives can be used. Preferred specific examples include bisphenol A diglycidyl ether (jER825, jER828, and jER834 (all trade names), manufactured by Mitsubishi Chemical Corporation) and bisphenol A propoxylate diglycidyl ether (manufactured by Sigma-Aldrich Co., LLC).

[0102] The bisphenol F-type epoxy resin that can be used in the present invention is not particularly limited, and a wide range of resins commonly used as the main agent of epoxy adhesives can be used. Preferred specific examples include bisphenol F diglycidyl ether (trade name: EPICLON 830, manufactured by DIC Corporation) and 4,4'-methylenebis(N,N-diglycidylaniline).

[0103] The phenol novolac epoxy resin that can be used in the present invention is not particularly limited, and a wide range of resins commonly used as the main agent of epoxy adhesives can be used. Such a phenol novolac epoxy resin is sold, for example, by Sigma-Aldrich Co. LLC under product number 406775.

[0104] (B) Curing agent

[0105] As the curing agent, any known curing agent for epoxy resins (preferably an organic compound) can be used without particular limitation, and examples thereof include aliphatic amines, aromatic amines, dicyandiamide, dihydrazide compounds, acid anhydrides, and phenol compounds.

[0106] From the perspective of increasing the crosslink density and reducing changes in the acoustic properties of the resulting material, it is preferred to use at least one of a primary amine (a compound having an unsubstituted amino group) and a secondary amine (a compound having a monosubstituted amino group), with a primary amine being more preferred. Compounds having both unsubstituted and monosubstituted amino groups are classified as secondary amines. Specific examples of compounds having at least one of an unsubstituted and monosubstituted amino group include isophoronediamine, mensendiamine, m-phenylenediamine, polyetheramine, polyamidoamine, triethylenetetramine, and piperidine.

[0107] <(C) Surface-treated tungsten carbide particles>

[0108] Component (C) is surface-treated tungsten carbide particles that have been surface-treated with a surface treatment agent comprising at least one of an aminosilane compound, a mercaptosilane compound, an isocyanatosilane compound, a thiocyanatosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound. Component (C) is a different component from component (B).

[0109] The average primary particle size of the tungsten carbide particles constituting the surface-treated tungsten carbide particles used in the present invention is not particularly limited. However, from the viewpoint of suppressing a decrease in the sound velocity of the acoustic matching sheet and reducing changes in the acoustic properties of the acoustic matching sheet, it is preferably 1 to 30 μm, more preferably 1 to 20 μm, and even more preferably 1 to 10 μm.

[0110] The average primary particle size of the component (C) is preferably 1 to 30 μm, more preferably 1 to 20 μm, and even more preferably 1 to 10 μm.

[0111] The average primary particle size can be determined by averaging the particle sizes measured using a transmission electron microscope (TEM). Specifically, the shortest and longest diameters of a single tungsten carbide particle in an electron micrograph taken by the TEM are measured, and the arithmetic average of these values is used as the particle size of the single tungsten carbide particle. In the present invention, the average primary particle size is determined by averaging the particle sizes of 300 randomly selected tungsten carbide particles.

[0112] Commercially available tungsten carbide particles can be used, and for example, WC (trade name) manufactured by ALMT Corp. can be mentioned.

[0113] From the perspective of suppressing the decrease in the sound velocity of the acoustic matching sheet and reducing the change in the acoustic properties of the acoustic matching sheet, the surface treatment agent used in the present invention preferably includes at least one of an aminosilane compound, an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound, more preferably includes at least one of an aluminum alkoxide compound, a zirconium alkoxide compound, and a titanium alkoxide compound, and further preferably includes at least one of a zirconium alkoxide compound and a titanium alkoxide compound.

[0114] Hereinafter, the surface treatment agent used in the present invention will be described in detail.

[0115] (Aminosilane compound)

[0116] The aminosilane compound (silane compound having an amino group) is preferably a silane coupling agent having an amino group. Preferably, the aminosilane compound does not have a Si-N-Si structure. In a "Si-N-Si structure," each silicon atom has three bonds, and each nitrogen atom has one bond.

[0117] The aminosilane compound preferably contains at least one compound represented by the following general formula (A).

[0118] [Chemical Formula 1]

[0119] General formula (A)

[0120] Where R 1 and R 2 represents a hydrogen atom or a substituent. 1a represents a single bond, an alkylene group, an alkenylene group, an alkynylene group, an arylene group, -O-, -S-, or -NR a -, ester bond, thioester bond, amide bond, sulfamide bond or sulfonyl group or a divalent group formed by combining two or more of these groups or bonds. a represents a hydrogen atom or a substituent. 1a Y represents a hydroxyl group or an alkoxy group. 2a and Y 3a represents a hydroxyl group, an alkoxy group, an alkyl group or a ketoximo group.

[0121] As R 1 and R 2 Examples of substituents that can be used include alkyl groups (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms), alkenyl groups (preferably having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms), alkynyl groups (preferably having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms), and aryl groups (preferably having 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms). These substituents may further have substituents, and examples of such substituents that can be used as R include 1 and R 2 The above-mentioned substituents and amino groups are listed as substituents.

[0122] And, R 1 and R 2 They may be combined to represent an alkylene group (preferably having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms).

[0123] L 1a Preferably represents an alkylene group, an alkenylene group, an arylene group, -O- or -NR a -, more preferably represents an alkylene group, an arylene group or -NR a -, more preferably represents an alkylene group.

[0124] Y 1a Preferably it represents an alkoxy group.

[0125] Y 2a and Y 3a It preferably represents a hydroxyl group, an alkoxy group or an alkyl group, and more preferably represents an alkoxy group or an alkyl group.

[0126] As L 1a The alkylene group that can be used may be any of linear, branched, and cyclic. The number of carbon atoms in the alkylene group is preferably 1 to 30, more preferably 1 to 25, further preferably 1 to 20, and further preferably 1 to 15. Specific examples of the alkylene group include methylene, ethylene, propylene, tert-butylene, pentylene, cyclohexylene, heptylene, octylene, nonyl, decyl, and undecene.

[0127] As L 1a The alkenylene group may be either linear or branched. The number of carbon atoms in the alkenylene group is preferably 2 to 20, more preferably 2 to 15, more preferably 2 to 10, and even more preferably 2 to 6. Specific examples of the alkenylene group include ethenylene and propenylene.

[0128] As L 1a The alkynylene group may be either linear or branched. The number of carbon atoms in the alkynylene group is preferably 2 to 20, more preferably 2 to 15, more preferably 2 to 10, and even more preferably 2 to 6. Specific examples of the alkynylene group include ethynylene and propynylene.

[0129] As L 1a The number of carbon atoms in the arylene group that can be used is preferably 6 to 20, more preferably 6 to 15, more preferably 6 to 12, and further preferably 6 to 10. Specific examples of the arylene group include a phenylene group and a naphthylene group.

[0130] AS-NR a -R a Examples of substituents that can be used include alkyl groups (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms), alkenyl groups (preferably having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms), alkynyl groups (preferably having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms), aryl groups (preferably having 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms), and heterocyclic groups. a The heterocyclic ring of the heterocyclic group that can be used may be a saturated or unsaturated aliphatic heterocyclic ring or an aromatic heterocyclic ring, and may be a monocyclic ring or a condensed ring. In addition, it may be a bridged ring. Examples of heteroatoms possessed by the heterocyclic ring include oxygen atoms, nitrogen atoms, and sulfur atoms. The number of heteroatoms contained in one heterocyclic ring is not particularly limited, but is preferably 1 to 3, more preferably 1 or 2. The number of carbon atoms in the heterocyclic ring is preferably 2 to 10, more preferably 4 or 5. The heterocyclic ring is preferably a 3- to 7-membered ring, more preferably a 3- to 6-membered ring, and further preferably a 3- to 5-membered ring. Specific examples of the heterocyclic ring include an epoxy ring, a 3,4-epoxycyclohexane ring, a furan ring, and a thiophene ring.

[0131] AS-NR a-, for example, -NH-.

[0132] As L 1a The divalent group (hereinafter also referred to as "L") formed by combining two or more of the above groups or bonds can be used. 1a The number of the combination groups or bonds that can be adopted is preferably 2 to 8, more preferably 2 to 6, and even more preferably 2 to 4.

[0133] And, as L 1a The molecular weight of the usable combining group is preferably 20 to 1,000, more preferably 30 to 500, and even more preferably 40 to 200.

[0134] As can be adopted as L 1a The combination groups include, for example, urea bond, thiourea bond, carbamate group, sulfonamide bond, arylene-alkylene, -O-alkylene, amide bond-alkylene, -S-alkylene, alkylene-O-amide bond-alkylene, alkylene-amide bond-alkylene, alkenylene-amide bond-alkylene, alkylene-ester bond-alkylene, arylene-ester bond-alkylene, -(alkylene-O)-, alkylene-O-(alkylene-O)-alkylene ("(alkylene-O)" are all repeating units), arylene-sulfonyl-O-alkylene and ester bond-alkylene.

[0135] Composition as Y 1a ~Y 3a The alkyl group in the alkoxy group may be linear, branched, or cyclic, or a combination of these. In the present invention, the alkyl group is preferably a linear alkyl group. The number of carbon atoms in the alkyl group constituting the alkoxy group is preferably 1 to 15, more preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 or 2. Specific examples of the alkyl group constituting the alkoxy group include methyl, ethyl, propyl, tert-butyl, pentyl, and cyclohexyl.

[0136] As can be adopted as Y 2a and Y 3a The alkyl group of Y can be exemplified by 1a ~Y 3a The alkyl group of the alkoxy group that can be used is preferably the same as that constituting Y. 1a ~Y 3a Preferred forms of the alkyl group of the alkoxy group that can be adopted are the same.

[0137] As Y 2a and Y 3a The ketoximo group that can be employed is a substituent having the following structure.

[0138] [Chemical Formula 2]

[0139]

[0140] In the above structure, R 11 and R 12 represents a substituent, and * represents a portion bonding to a silicon atom.

[0141] As R 11 and R 12 The substituents that can be used include the above-mentioned R a The substituents in the preferred form are also the same as those in the a Preferred aspects of the substituents that can be adopted are the same.

[0142] Examples of the ketoxime group include a dimethylketoxime group, a methylethylketoxime group, and a diethylketoxime group.

[0143] Specific examples of the aminosilane compound used in the present invention are given below, but the present invention is not limited thereto.

[0144] 3-Aminopropyltrimethoxysilane

[0145] 3-Aminopropyldimethylmethoxysilane

[0146] 3-Aminopropylmethyldimethoxysilane

[0147] 3-Aminopropylmethyldiethoxysilane

[0148] 3-Aminopropyltriethoxysilane

[0149] N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane

[0150] N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane

[0151] N-(2-aminoethyl)-3-aminopropyltrimethoxysilane

[0152] N-(2-aminoethyl)-3-aminopropyltriethoxysilane

[0153] 3-Methyldimethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine

[0154] 3-Methyldiethoxysilyl-N-(1,3-dimethylbutylidene)propylamine

[0155] 3-Trimethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine

[0156] 3-Triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine

[0157] N-phenyl-3-aminopropylmethyldimethoxysilane

[0158] N-phenyl-3-aminopropylmethyldiethoxysilane

[0159] N-phenyl-3-aminopropyltrimethoxysilane

[0160] N-phenyl-3-aminopropyltriethoxysilane

[0161] N-(Vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane

[0162] (Mercaptosilane compound)

[0163] The mercaptosilane compound (a silane compound having a mercapto (sulfanyl) group) is preferably a silane coupling agent having a mercapto group. The tungsten carbide particles surface-treated with the mercaptosilane compound preferably have a mercapto group derived from the mercaptosilane compound.

[0164] The mercaptosilane compound preferably contains at least one compound represented by the following general formula (B).

[0165] [Chemical Formula 3]

[0166] General formula (B)

[0167] L 1b 、Y 1b 、Y 2b and Y 3b The meanings of L are respectively the same as those of L in the above general formula (A) 1a 、Y 1a 、Y 2a and Y 3a The meanings and preferred ranges are the same.

[0168] Specific examples of the mercaptosilane compound used in the present invention are given below, but the present invention is not limited thereto.

[0169] 3-Mercaptopropyltrimethoxysilane

[0170] 3-Mercaptopropyltriethoxysilane

[0171] 3-Mercaptopropylmethyldimethoxysilane

[0172] Mercaptomethylmethyldiethoxysilane

[0173] (Mercaptomethyl)methyldimethoxysilane

[0174] (Mercaptomethyl)dimethylethoxysilane

[0175] 11-Mercaptoundecyltrimethoxysilane

[0176] (Isocyanatosilane compound)

[0177] The isocyanatosilane compound (preferably a silane compound having an isocyanate group) is preferably a silane coupling agent having an isocyanate group. The tungsten carbide particles surface-treated with the isocyanatosilane compound preferably have an isocyanate group derived from the isocyanatosilane compound.

[0178] The isocyanatosilane compound preferably contains at least one compound represented by the following general formula (C).

[0179] [Chemical Formula 4]

[0180] General formula (C)

[0181] L 1c 、Y 1c 、Y 2c and Y 3c The meaning of L in the above general formula (A) is the same as 1a 、Y 1a 、Y 2a and Y 3a 's have the same meanings and the preferred ranges are also the same.

[0182] Furthermore, in the present invention, as the isocyanatosilane compound, it is also preferred to use a condensate of a compound represented by the above-mentioned general formula (C) and a compound in which the isocyanate group of the above-mentioned general formula (C) is protected by a substituent. The above-mentioned substituent can be introduced, for example, via an alcohol compound, a phenol compound, an aromatic amine, a lactam, and an oxime. Examples of these alcohol compounds include alkyl alcohols (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms). Examples of phenol compounds include phenol and cresol. Examples of lactams include ε-caprolactam.

[0183] The "compound in which the isocyanate group of the general formula (C) is protected by a substituent" means that -NCO of the general formula (C) is replaced by -NHC(=O)OR 4 Substituted compounds. 4 represents a substituent, and examples thereof include an alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms).

[0184] Specific examples of the isocyanate silane compound used in the present invention are given below, but the present invention is not limited thereto.

[0185] 3-Isocyanatopropyltrimethoxysilane

[0186] 3-Isocyanatopropyltriethoxysilane

[0187] Isocyanatomethyltrimethoxysilane

[0188] (The following are isocyanatosilane compounds protected by condensation or substituents)

[0189] Tris(3-trimethoxysilylpropyl)isocyanurate

[0190] (3-Triethoxysilylpropyl)-tert-butylcarbamate

[0191] Triethoxysilylpropylethylcarbamate

[0192] (Thiocyanatosilane compound)

[0193] The thiocyanate silane compound (silane compound having a thiocyanate group) is preferably a silane coupling agent having a thiocyanate group. The tungsten carbide particles surface-treated with the thiocyanate silane compound preferably have a thiocyanate group derived from the thiocyanate silane compound.

[0194] The thiocyanatosilane compound preferably contains at least one compound represented by the following general formula (D).

[0195] [Chemical Formula 5]

[0196] General formula (D)

[0197] L 1d 、Y 1d 、Y 2d and Y 3d The meaning of L is the same as that of L in the above general formula (A) 1a 、Y 1a 、Y 2a and Y 3a 's have the same meanings and the preferred ranges are also the same.

[0198] Specific examples of the thiocyanate silane compound used in the present invention are given below, but the present invention is not limited thereto.

[0199] 3-Thiocyanatepropyltrimethoxysilane

[0200] 3-Thiocyanatepropyltriethoxysilane

[0201] Thioaminomethyltrimethoxysilane

[0202] (Aluminum alkoxide compound)

[0203] The aluminum alkoxide compound preferably contains at least one of an acetonate structure and an acetate structure.

[0204] The aluminum alkoxide compound preferably contains at least one compound represented by the following general formula (1).

[0205] General formula (1): R 1am1 -Al-(OR 2a ) 3-m1

[0206] R 1a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group or an unsaturated aliphatic group,

[0207] As R 1a Alkyl groups that can be used include linear and branched alkyl groups and aralkyl groups. The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 1 to 15, even more preferably 1 to 10, and particularly preferably 1 to 8. In the case of an aralkyl group, the number of carbon atoms is preferably 7 to 30. Specific examples of preferred alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, decyl, tridecyl, octadecyl, benzyl, and phenethyl.

[0208] As R 1a The alkyl group that can be used preferably has an oxirane ring. 1a The number of rings of the cycloalkyl group (cycloalkyl group having a structure formed by condensing ethylene oxide rings) in the cyclooxyalkyl group that can be used is preferably 4 to 8, more preferably 5 or 6, and further preferably 6 (ie, cyclohexyl oxide).

[0209] And, as R 1a The alkyl group that can be used preferably has a group selected from an amino group, an isocyanate group, a mercapto group, an ethylenically unsaturated group, and an acid anhydride group.

[0210] As R 1a The number of carbon atoms in the cycloalkyl group that can be used is preferably 3 to 20, more preferably 3 to 15, further preferably 3 to 10, and particularly preferably 3 to 8. Preferred specific examples of the cycloalkyl group include cyclopropyl, cyclopentyl, and cyclohexyl.

[0211] As R 1a The number of carbon atoms in the acyl group that can be used is preferably 2 to 40, more preferably 2 to 30, further preferably 2 to 20, and particularly preferably 2 to 18.

[0212] As R 1a The number of carbon atoms in the aryl group that can be used is preferably 6 to 20, more preferably 6 to 15, further preferably 6 to 12, and particularly preferably 6 to 10. Specific preferred examples of the aryl group include phenyl and naphthyl, with phenyl being more preferred.

[0213] As R 1aThe number of carbon-carbon unsaturated bonds in the unsaturated aliphatic group that can be used is preferably 1 to 5, more preferably 1 to 3, even more preferably 1 or 2, and particularly preferably 1. The unsaturated aliphatic group may contain heteroatoms and is preferably a hydrocarbon group. When the unsaturated aliphatic group is a hydrocarbon group, the number of carbon atoms is preferably 2 to 20, more preferably 2 to 15, even more preferably 2 to 10, even more preferably 2 to 8, and even more preferably 2 to 5. The unsaturated aliphatic group is more preferably an alkenyl group or an alkynyl group.

[0214] R 1a A hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group is preferred, and an alkyl group or a cycloalkyl group is more preferred.

[0215] In the compound of general formula (1) having two or more R 1a In the case of two R 1a They can be connected to each other to form a ring.

[0216] R 2a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group (phosphonic acid group) or -SO2R S1 . R S1 represents a substituent,

[0217] As R 2a The meanings of the alkyl, cycloalkyl, acyl and aryl groups that can be used are the same as those of the R 1a The alkyl, cycloalkyl, acyl and aryl groups that can be used have the same meanings, and the preferred forms of each group are also the same. 2a The alkyl group that can be used preferably has an amino group as a substituent.

[0218] As R 2a Examples of alkenyl groups include linear and branched alkenyl groups. The number of carbon atoms in the alkenyl group is preferably 2 to 18, more preferably 2 to 7, and even more preferably 2 to 5. Preferred examples of the alkenyl group include vinyl, allyl, butenyl, pentenyl, and hexenyl. The alkenyl group is preferably a substituted alkenyl group.

[0219] As R 2a The phosphonate group that can be used is represented by -P(=O)(-OR P1 )OR P2 The group represented by R P1 and R P2 represents a hydrogen atom or a substituent, and the substituent is preferably an alkyl group or a phosphonate group. P1 and R P2 The meaning of the alkyl group that can be used is the same as that of the above-mentioned R 1a The meanings of the alkyl groups that can be adopted are the same, and the preferred forms of the alkyl groups are also the same. P1 and R P2 The meaning of the phosphonate group that can be used is the same as that of the group R2a The phosphonate groups that can be used have the same meanings and the same preferred forms. P1 or R P2 In the case of a phosphonate group, R constituting the phosphonate group P1 and R P2 Alkyl groups are preferred.

[0220] As R 2a The phosphonate group that can be used is preferably R P1 and R P2 All are alkyl or R P1 is a hydrogen atom, R P2 It is a phosphonate group.

[0221] In addition, a phosphonate group and a phosphite group (phosphite group) are tautomers, and therefore the phosphonate group in the present invention includes a phosphite group.

[0222] As R 2a Available-SO2R S1 In the case of a substituent R S1 Alkyl or aryl is preferred. S1 Preferred forms of the alkyl and aryl groups include the above-mentioned R 1a The preferred forms of alkyl and aryl groups that can be used are: S1 Preferably, the phenyl group has an alkyl group as a substituent. The preferred embodiment of the alkyl group is the same as that of the above-mentioned R 1a Preferred forms of the alkyl group that can be adopted are the same.

[0223] The compound represented by the general formula (1) has two or more R 2a In the case of two R 2a They can be connected to each other to form a ring.

[0224] m1 is an integer from 0 to 2.

[0225] In the above general formula (1), preferably OR 2a At least one of them has an acetonato structure. The acetonato structure refers to a structure in which a hydrogen ion is removed from acetone or a compound having a structure in which acetone has a substituent and coordinated with Al. The coordinating atom coordinated with the Al is usually an oxygen atom. The acetonato structure preferably has an acetylacetone structure ("CH3-C(=O)-CH2-C(=O)-CH3") as a basic structure, and a structure in which a hydrogen ion is removed from the basic structure and an oxygen atom is coordinated with Al as a coordinating atom (i.e., an acetylacetonato structure). The above-mentioned "having an acetylacetone structure as a basic structure" means that, in addition to the above-mentioned acetylacetone structure, it also includes a structure in which the hydrogen atom of the above-mentioned acetylacetone structure is replaced by a substituent. As OR 2aExamples of the form having an acetonato structure include compounds SL-2 and SL-3 described below.

[0226] In the above general formula (1), OR 2a At least one of them has an acetate structure. In the present invention, the acetate structure refers to a structure in which one hydrogen ion is removed from acetic acid or an acetate ester or a compound having a structure with a substituent (including a form in which the methyl group of acetic acid has an alkyl group as a substituent) and coordinated with Al. The coordinating atom coordinated with the Al is usually an oxygen atom. The acetate structure is preferably the following structure (i.e., alkyl acetoacetate structure): with an alkyl acetoacetate structure ("CH3-C(=O)-CH2-C(=O)-OR alk ”(R alk It represents an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms). )) as a basic structure, a structure in which one hydrogen ion is removed from the basic structure and an oxygen atom is used as a coordinating atom to coordinate with Al. The above-mentioned "using an alkyl acetoacetate structure as a basic structure" means that, in addition to the above-mentioned alkyl acetoacetate structure, a structure in which a hydrogen atom of the above-mentioned alkyl acetoacetate structure is replaced by a substituent is included. As OR 2a Examples of the form having an acetate structure include compounds SL-3, SL-4, and SL-5 described below.

[0227] As the above R 1a or R 2a Each group that can be used may contain an anionic group (salt-type substituent) having a counter cation as a substituent. Anionic group refers to a group that can form an anion. As the above-mentioned anionic group having a counter cation, for example, a group of carboxylic acid ions using ammonium ions as counter cations can be cited. In this case, the counter cation exists in the compound represented by the general formula (1) so that the charge of the entire compound is 0. This is also the same for the compound represented by the general formula (2) and the compound represented by the general formula (3) described later.

[0228] Specific examples of the aluminum alkoxide compound used in the present invention are given below, but the present invention is not limited thereto.

[0229] Aluminum triethylate

[0230] Aluminum triisopropoxide

[0231] Aluminum tri-sec-butyrate

[0232] Aluminum tris(ethyl acetoacetate)

[0233] Aluminum monoacetylacetonate bis(acetoacetate)

[0234] Aluminum tris(acetylacetonate)

[0235] Diisopropoxyaluminum-9-octadecene acetate

[0236] Aluminum diisopropoxy monoethyl acetate

[0237] Aluminum triacetoacetate

[0238] Aluminum triacetylacetonate

[0239] Mono-sec-butoxyaluminum diisopropylate

[0240] Aluminum diisopropylate ethyl acetoacetate

[0241] Diethyl acetate Aluminum acetate isopropylate

[0242] Ethyl bisacetoacetate Aluminum monoacetylacetonate

[0243] Octadecylaluminum acetate diisopropyl acetate

[0244] (Zirconium alkoxide compound)

[0245] The zirconium alkoxide compound preferably contains at least one of an acetonate structure, an acetate structure, and a lactate structure, and more preferably contains at least one of an acetonate structure and an acetate structure.

[0246] The zirconium alkoxide compound preferably contains a compound represented by the following general formula (2).

[0247] General formula (2): R 1b m2 -Zr-(OR 2b ) 4-m2

[0248] R 1b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group or an unsaturated aliphatic group,

[0249] As the alkyl group, cycloalkyl group, acyl group, aryl group and unsaturated aliphatic group, for example, R in the above general formula (1) can be used. 1a Alkyl groups, cycloalkyl groups, acyl groups, aryl groups and unsaturated aliphatic groups can be used.

[0250] R 2b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group or -SO2R S2 , R S2 represents a substituent,

[0251] As the alkyl group, cycloalkyl group, acyl group, alkenyl group, aryl group and phosphonate group, for example, R in the above general formula (1) can be used.2a Alkyl, cycloalkyl, acyl, alkenyl, aryl, phosphonate, and the like can be used. S2 The substituents of R in the general formula (1) can be used, for example S1 Substituents that can be used.

[0252] m2 is an integer from 0 to 3.

[0253] In the above general formula (2), OR is preferably 2b At least one of them has an acetonato structure. The meaning of the acetonato structure is the same as that of the acetonato structure described in general formula (1). 2b Examples of the form having an acetonato structure include compounds SZ-3 and SZ-6 described below.

[0254] Furthermore, in the above general formula (2), it is preferred that OR 2b At least one of them has an acetate structure. The meaning of the acetate structure is the same as that of the acetate structure described in general formula (1). 2b The form having an acetate structure includes, for example, the compound SZ-7 described below. In addition, the compound SZ-5 corresponds to R in the general formula (1). 2b In the form of acyl group.

[0255] Furthermore, in the above general formula (2), it is preferred that OR 2b At least one of them has a lactate structure. The lactate structure refers to a structure in which a lactate ion is used as a basic structure and one hydrogen ion is removed from the basic structure to coordinate with Zr. The above-mentioned "using a lactate ion as a basic structure" refers to a structure in which, in addition to the lactate ion, the hydrogen atom of the lactate ion is replaced by a substituent. The coordinating atom coordinated with the Zr is usually an oxygen atom. As OR 2b Examples of the form having a lactate structure include the compound SZ-4 described below.

[0256] Specific examples of the zirconium alkoxide compound used in the present invention are given below, but the present invention is not limited thereto.

[0257] Tetrapropoxyzirconium (also known as zirconium tetra-n-propoxide)

[0258] Zirconium tetrabutoxide (also known as zirconium tetra-n-butoxide)

[0259] Zirconium tetraacetylacetonate

[0260] Zirconium tributoxymonoacetylacetonate

[0261] Zirconium dibutoxybis(acetylacetonate)

[0262] Dibutoxybis(ethyl acetoacetate)zirconium

[0263] Zirconium ethyl tributoxyacetoacetate

[0264] Monobutoxyzirconium acetylacetonate bis(ethyl acetoacetate)

[0265] Zirconium tributoxy monostearate (also known as zirconium tri-n-butyl stearate)

[0266] Zirconium stearate

[0267] Ammonium zirconium lactate

[0268] Zirconium monoacetylacetonate

[0269] (Titanium alkoxide compound)

[0270] The titanium alkoxide compound preferably contains at least one atom of N, P, and S. Furthermore, the titanium alkoxide compound preferably has an acetate structure.

[0271] The titanium alkoxide compound preferably contains at least one compound represented by the following general formula (3).

[0272] General formula (3): R 1c m3 -Ti-(OR 2c ) 4-m3

[0273] R 1c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group or an unsaturated aliphatic group,

[0274] As the alkyl group, cycloalkyl group, acyl group, aryl group and unsaturated aliphatic group, for example, R in the above general formula (1) can be used. 1a Alkyl groups, cycloalkyl groups, acyl groups, aryl groups and unsaturated aliphatic groups can be used.

[0275] R 2c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group or -SO2R S3 , R S3 represents a substituent,

[0276] As the alkyl group, cycloalkyl group, acyl group, alkenyl group, aryl group and phosphonate group, for example, R in the above general formula (1) can be used. 2a Alkyl, cycloalkyl, acyl, alkenyl, aryl, phosphonate, and the like can be used. S3 The substituents of R in the general formula (1) can be used, for example S1 Substituents that can be used.

[0277] m3 is an integer from 0 to 3.

[0278] The compound represented by the general formula (3) described above preferably contains at least one atom of N, P, and S. When the compound represented by the general formula (3) has N, it preferably has the N as an amino group.

[0279] When the compound represented by the general formula (3) has P, it preferably has P as a phosphate group (phosphate) or a phosphonate group (phosphonic acid group).

[0280] When the compound represented by the general formula (3) has S, it preferably has the S as a sulfonyl group (—SO 2 —).

[0281] Furthermore, the compound represented by the general formula (3) mentioned above preferably has an acyl group as R 2c , i.e. having the above-mentioned acetate structure as OR 2c .

[0282] Specific examples of the titanium alkoxide compound used in the present invention are given below, but the present invention is not limited thereto.

[0283] Isopropyl triisostearyl titanate

[0284] Isopropyl tridodecylbenzenesulfonyl titanate

[0285] Isopropyl trioctanoyl titanate

[0286] Isopropyl tri(dioctyl phosphite) titanate

[0287] Isopropyl tris(dioctyl pyrophosphate) titanate

[0288] Isopropyl tri(dioctyl sulfate) titanate

[0289] Isopropyl tricumylphenyl titanate

[0290] Isopropyl tris(N-aminoethyl-aminoethyl) titanate

[0291] Isopropyl Dimethicone Isostearyl Titanate

[0292] Isopropyl isostearyl titanate diacrylate

[0293] Isobutyl trimethyl titanate

[0294] Ethylene diisostearyl titanate

[0295] Diisopropyl bis(dioctyl pyrophosphate) titanate

[0296] Dioctyl bis(ditridecyl phosphate) titanate

[0297] Dicumylphenyloxyacetate titanate

[0298] Bis(dioctyl pyrophosphate)oxyacetate titanate

[0299] Bis(dioctyl pyrophosphate)ethylene titanate

[0300] Tetraisopropyl titanate

[0301] Tetrabutyl titanate

[0302] Tetraoctyl titanate

[0303] Tetrastearyl titanate

[0304] Tetraisopropyl bis(dioctyl phosphite) titanate

[0305] Tetraoctylbis(di-tridecylphosphite) titanate

[0306] Tetrakis(2,2-diallyloxymethyl-1-butyl)bis(di-tridecyl)phosphite titanate

[0307] Butyl titanate dimer

[0308] Titanium tetraacetylacetonate

[0309] Titanium acetoacetate

[0310] Titanium Octanoate

[0311] Bis-2-ethylhexyloxybis(2-ethyl-3-hydroxyhexyloxy)titanium

[0312] In component (C), the mass ratio of tungsten carbide particles to the surface treatment agent is not particularly limited. For example, the surface treatment agent is preferably 1 to 100 parts by mass, more preferably 1 to 80 parts by mass, relative to 100 parts by mass of tungsten carbide particles. From the viewpoint of suppressing a decrease in the sound velocity of the acoustic matching sheet and reducing changes in the acoustic properties of the acoustic matching sheet, the surface treatment agent is more preferably 1 to 50 parts by mass, more preferably 5 to 50 parts by mass, and even more preferably 10 to 50 parts by mass.

[0313] The mass ratio of tungsten carbide particles to the surface treatment agent in component (C) has the same meaning as the mass ratio of tungsten carbide particles to the amount of surface treatment agent used during surface treatment. The mass ratio of tungsten carbide particles to the surface treatment agent in component (C) can be calculated from the mass of the tungsten carbide particles and the mass of component (C) after heating component (C) to 500°C or higher to remove the organic component using thermogravimetric analysis (TGA) or the like to obtain the inorganic component (tungsten carbide particles).

[0314] Furthermore, surface treatment agents other than the above-mentioned surface treatment agents may be used within a range not impairing the effects of the present invention.

[0315] The above-mentioned surface treatment method itself can be carried out by a conventional method.

[0316] Regarding component (C), it is not necessary to treat the entire surface of the tungsten carbide particles with a surface treatment agent. For example, out of 100% of the surface area of the tungsten carbide particles, preferably 50% or more is surface treated, more preferably 70% or more is surface treated, and further preferably 90% or more is surface treated.

[0317] Component (C) may be used alone or in combination of two or more.

[0318] From the perspective of further improving acoustic impedance, the content of component (C) is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, more preferably 80 parts by mass or more, and even more preferably 90 parts by mass or more, based on a total of 100 parts by mass of the respective contents of components (A) to (C). Furthermore, the content of component (C) is preferably 98 parts by mass or less, more preferably 95 parts by mass or less, and even more preferably 94 parts by mass or less, based on a total of 100 parts by mass of the respective contents of components (A) to (C). By setting the content of component (C) to 90 parts by mass or more and 94 parts by mass or less, changes in acoustic properties can be effectively suppressed.

[0319] Furthermore, the contents of the components (A) and (B) in 100 parts by mass of the total of the contents of the components (A) to (C) are preferably within the following ranges.

[0320] The content of component (A) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 4 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 9 parts by mass or less, and even more preferably 8 parts by mass or less.

[0321] The content of component (B) is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and further preferably 0.14 parts by mass or more, and is preferably 4 parts by mass or less, more preferably 3 parts by mass or less, and further preferably 2.5 parts by mass or less.

[0322] The content ratio of component (A) to component (B) may be appropriately adjusted depending on the type of component (B) used, etc. For example, in terms of mass ratio, component (A) / component (B) can be 99 / 1 to 20 / 80, preferably 90 / 1 to 40 / 60, and more preferably 90 / 1 to 75 / 25.

[0323] Surface modification process

[0324] Furthermore, from the perspective of suppressing the decrease in the sound velocity of the acoustic matching sheet and reducing the change in the acoustic properties of the acoustic matching sheet, the surface-treated tungsten carbide particles used in the present invention can be brought into contact with tungsten carbide particles and an oxidizing agent in an aqueous solution before being surface-treated with the above-mentioned surface treatment agent to modify the surface of the tungsten carbide particles.

[0325] The surface modification step is a step of bringing tungsten carbide particles into contact with an oxidizing agent in an aqueous solution to obtain modified tungsten carbide particles.

[0326] The pH of the aqueous solution is, for example, greater than 7, preferably 10 or greater, more preferably 12 or greater, further preferably greater than 12, particularly preferably 13 or greater, and most preferably greater than 13.

[0327] The upper limit of the pH of the aqueous solution is not limited, and is, for example, 14 or less.

[0328] The pH of the aqueous solution refers to the pH of the aqueous solution containing the tungsten carbide particles and the oxidant. That is, the aqueous solution contains at least water, tungsten carbide particles, and the oxidant.

[0329] The time for contacting the tungsten carbide particles with the oxidizing agent in the aqueous solution is preferably 0.1 to 24 hours, more preferably 0.5 to 10 hours, and even more preferably 1.5 to 6 hours.

[0330] Furthermore, the temperature of the aqueous solution when the tungsten carbide particles are brought into contact with the oxidizing agent is preferably 1 to 95°C, more preferably 25 to 80°C, and even more preferably 45 to 65°C.

[0331] There is no limitation on the method for bringing the tungsten carbide particles into contact with the oxidant in the aqueous solution. For example, there can be mentioned: a method of bringing the tungsten carbide particles into contact by mixing them using a pulverizer or crusher such as a shaker, a bead mill, a ball mill, a Henschel mixer, a jet mill, a starburst, or a paint conditioner; a method of bringing them into contact while stirring them using a mechanical stirrer such as a three-in-one motor or an electromagnetic stirrer; and a method of bringing them into contact while circulating an oxidant aqueous solution containing the oxidant using a pump in a box filled with tungsten carbide particles.

[0332] Furthermore, as a method for contacting the tungsten carbide particles with the oxidant in the aqueous solution, a method can be selected that minimizes the destruction of the tungsten carbide particles or modifies the tungsten carbide particles in the aqueous solution. For example, the destruction mentioned herein includes, when the tungsten carbide particles being treated are agglomerated tungsten carbide particles, the destruction of their agglomerated form.

[0333] After the tungsten carbide particles are brought into contact with the oxidizing agent in the aqueous solution, the obtained modified tungsten carbide particles are preferably taken out from the aqueous solution.

[0334] The method for taking out the modified tungsten carbide particles from the aqueous solution is not limited. For example, there can be mentioned a method of filtering the aqueous solution and fractionating (filtering) the modified tungsten carbide particles as a filtrate.

[0335] It is also preferable to wash the taken-out modified tungsten carbide particles with water and / or an organic solvent.

[0336] (Oxidant)

[0337] The above aqueous solution contains an oxidizing agent.

[0338] The oxidizing agent is not limited, and examples thereof include: persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; nitrates such as ceric ammonium nitrate, sodium nitrate, and ammonium nitrate; peroxides such as hydrogen peroxide and tert-butyl hydroperoxide; permanganates such as potassium permanganate; divalent copper compounds and transition metal compounds; periodinanes such as potassium periodate and sodium periodate; quinone compounds such as benzoquinone, naphthoquinone, anthraquinone, and chloranil; and salts of halogen oxygen acids such as sodium hypochlorite and sodium chlorite.

[0339] Among them, the oxidizing agent preferably contains persulfate, and more preferably the oxidizing agent is persulfate.

[0340] Furthermore, in order to assist the action of the oxidant, a catalyst may be used separately from the oxidant. Examples of the catalyst include divalent iron compounds (FeSO4, etc.) and trivalent iron compounds.

[0341] In addition, the oxidizing agent and / or the catalyst may be a hydrate.

[0342] The standard redox potential of the oxidant is preferably 0.30 V or higher, more preferably 1.50 V or higher, and even more preferably 1.70 V or higher. The upper limit of the standard redox potential of the oxidant is not particularly limited, but is preferably 4.00 V or lower, and more preferably 2.50 V or lower, for example.

[0343] The above standard redox potential is based on the standard hydrogen electrode.

[0344] In the aqueous solution, the content of the oxidizing agent is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 1 to 20 parts by mass, relative to 100 parts by mass of water in the aqueous solution.

[0345] The oxidizing agent may be used alone or in combination of two or more.

[0346] When the aqueous solution contains a catalyst, the content thereof is preferably 0.005 to 2 parts by mass, more preferably 0.01 to 2 parts by mass, and even more preferably 0.1 to 2 parts by mass, relative to 100 parts by mass of water in the aqueous solution.

[0347] The content of the catalyst in the aqueous solution is preferably 0.1 to 80 parts by mass, more preferably 1 to 50 parts by mass, and even more preferably 5 to 20 parts by mass, based on 100 parts by mass of the oxidizing agent in the aqueous solution.

[0348] The catalyst may be used alone or in combination of two or more.

[0349] The amount of the oxidizing agent in contact with the tungsten carbide particles is preferably 0.1 to 1000 parts by mass, more preferably 1 to 250 parts by mass, and even more preferably 15 to 120 parts by mass, relative to 100 parts by mass of the tungsten carbide particles.

[0350] (Alkali Source)

[0351] In order to adjust the pH of the aqueous solution, the aqueous solution preferably contains an alkali source in addition to the above components.

[0352] Examples of the alkali source include inorganic bases such as alkali metal hydroxides (sodium hydroxide, etc.) and alkaline earth metal hydroxides; and organic bases.

[0353] The content of the alkaline source in the aqueous solution may be appropriately adjusted to adjust the pH of the aqueous solution to a desired pH. For example, the content of the alkaline source is 0.1 to 10 parts by mass based on 100 parts by mass of water in the aqueous solution.

[0354] <Other ingredients>

[0355] The material of the present invention may contain, in addition to components (A) to (C), a curing retarder, a dispersant, a pigment, a dye, an antistatic agent, an antioxidant, a flame retardant, and a thermal conductivity improver.

[0356] <Preparation of Acoustic Matching Layer Materials>

[0357] When the material of the present invention is in the form of an acoustic matching layer composition obtained by mixing components (A) to (C), the mixing method is not particularly limited as long as the components can be substantially uniformly mixed. For example, kneading using a rotating or revolving mixer (planetary mixer) can achieve the desired uniform mixing. By curing this mixture while molding, an acoustic matching sheet or its precursor can be prepared.

[0358] Furthermore, when the material of the present invention is in the form of an acoustic matching layer kit (as described in the above embodiment (ii)) comprising a main agent (including components (A) and (C)) and a curing agent for component (B), the main agent can be obtained by mixing components (A) and (C). When producing an acoustic matching sheet, the main agent and curing agent can be mixed, and the mixture can be molded and cured to produce the acoustic matching sheet or its precursor.

[0359] [Acoustic Matching Sheet (Acoustic Matching Layer)]

[0360] The acoustic matching sheet of the present invention can be obtained by molding and solidifying the mixture of the above-mentioned components and then cutting or dicing the mixture as needed. Furthermore, the acoustic matching sheet can be further processed into a desired shape by conventional methods.

[0361] Specifically, for example, the material of the present invention is formed into a desired sheet shape in a low-temperature region where a curing reaction does not occur, or in a low-temperature region where the curing rate is sufficiently slow. Subsequently, after curing the material by heating or other means as needed to obtain a cured product, the cured product is cut or diced to the desired thickness or shape, thereby forming an acoustic matching sheet. Specifically, the resulting acoustic matching sheet is preferably a cured product formed by curing a mixture of the various components that make up the material of the present invention. This acoustic matching sheet serves as the acoustic matching layer of an acoustic wave probe. The structure of an acoustic wave probe including an acoustic matching layer will be described later.

[0362] [Sonic probe]

[0363] The acoustic wave probe of the present invention includes the acoustic matching sheet of the present invention as at least one acoustic matching layer.

[0364] An example of the structure of the acoustic wave probe of the present invention is shown in FIG. Figure 1 middle. Figure 1 The ultrasonic probe shown is an ultrasonic probe used in an ultrasonic diagnostic device. Furthermore, an ultrasonic probe is a probe that uses ultrasound waves as the sound waves in the ultrasonic probe. Therefore, the basic structure of the ultrasonic probe can be directly applied to the ultrasonic probe.

[0365] Ultrasonic probe

[0366] The ultrasonic probe 10 is a main component of the ultrasonic diagnostic apparatus, which has the function of transmitting and receiving ultrasonic beams while generating ultrasonic waves. Figure 1 As shown, an acoustic lens 1, an acoustic matching layer 2, a piezoelectric element layer 3, and a backing material 4 are provided in this order from the front end (the surface that contacts the living organism being examined). Furthermore, in recent years, proposals have been made to form a stacked structure with different materials for the transmitting and receiving ultrasonic transducers (piezoelectric elements) for the purpose of receiving higher harmonics.

[0367] (Piezoelectric element layer)

[0368] The piezoelectric element layer 3 is a portion that generates ultrasonic waves. Electrodes are attached to both sides of the piezoelectric element. When voltage is applied, the piezoelectric element repeats contraction and expansion and vibrates, thereby generating ultrasonic waves.

[0369] Piezoelectric elements are widely made of so-called ceramic inorganic piezoelectrics, which are formed by polarizing single crystals such as quartz crystal, LiNbO3, LiTaO3, and KNbO3, thin films of ZnO and AlN, and sintered bodies of Pb(Zr, Ti)O3 systems. Piezoelectric ceramics such as PZT (lead zirconate titanate), which offer excellent conversion efficiency, are commonly used.

[0370] Furthermore, piezoelectric elements that detect high-frequency received waves need to have a wider bandwidth of sensitivity. Therefore, organic piezoelectrics using organic polymers such as polyvinylidene fluoride (PVDF) are used as piezoelectric elements suitable for high frequencies and wide bandwidths.

[0371] Furthermore, Japanese Patent Application Laid-Open No. 2011-071842 describes a cMUT utilizing MEMS (Micro Electro Mechanical Systems) technology, which exhibits excellent short pulse and broadband characteristics, is highly mass-productive, and can provide an array structure with little characteristic variation.

[0372] In the present invention, any piezoelectric element material can be preferably used.

[0373] (Backing material)

[0374] The backing material 4 is provided on the back surface of the piezoelectric element layer 3 , and reduces the pulse width of the ultrasonic wave by suppressing unnecessary vibration, thereby contributing to improving the distance resolution in the ultrasonic diagnostic image.

[0375] (Acoustic Matching Layer)

[0376] The acoustic matching layer 2 is provided to reduce the difference in acoustic impedance between the piezoelectric element layer 3 and the object under examination and to efficiently transmit and receive ultrasonic waves.

[0377] (Acoustic Lens)

[0378] The acoustic lens 1 is designed to focus ultrasound waves in the slice direction by refraction, thereby improving resolution. Furthermore, it must be in close contact with the living body being examined, ensuring that the acoustic impedance of the ultrasound waves matches that of the living body (1.4-1.7 Mrayl in the human body), and that the acoustic lens 1 itself minimizes ultrasound attenuation.

[0379] Specifically, the acoustic lens 1 is made of a material having a sound velocity sufficiently lower than that of the human body, which reduces ultrasonic attenuation and has an acoustic impedance close to that of human skin, thereby improving ultrasonic transmission and reception sensitivity.

[0380] The operation of the ultrasonic probe 10 having this structure will be described. Voltage is applied to electrodes on both sides of the piezoelectric element layer, causing the piezoelectric element layer 3 to resonate, transmitting an ultrasonic signal from the acoustic lens to the subject. During reception, the reflected signal (echo signal) from the subject causes the piezoelectric element layer 3 to vibrate, which is then electrically converted into a signal, resulting in an image.

[0381] [Manufacturing of ultrasonic probes]

[0382] The acoustic wave probe of the present invention can be manufactured using conventional methods, in addition to using the material of the present invention. Specifically, the method for manufacturing the acoustic wave probe of the present invention includes forming an acoustic matching layer on the piezoelectric element side using the material of the present invention. The piezoelectric element can be disposed on the backing material using conventional methods.

[0383] Then, an acoustic lens is formed on the acoustic matching layer by a conventional method using a material for forming the acoustic lens.

[0384] [Sound wave measuring device]

[0385] The acoustic wave measuring device of the present invention includes the acoustic wave probe of the present invention and has a function of displaying the signal strength of a signal received by the acoustic wave probe or imaging the signal.

[0386] The acoustic wave measuring device of the present invention is preferably an ultrasonic diagnostic device using an ultrasonic probe.

[0387] Example

[0388] The present invention will be described in further detail below based on an embodiment using ultrasound as the sound wave. Furthermore, the present invention is not limited to ultrasound, and sound waves of audible frequencies may also be used as long as an appropriate frequency is selected according to the subject and measurement conditions.

[0389] [Preparation Example] Preparation Example of Surface-treated Tungsten Carbide Particles (C-1)

[0390] 3.0 parts by mass of 3-aminopropyltrimethoxysilane, 100 parts by mass of methanol, and 3.3 parts by mass of distilled water were mixed and allowed to stand at 23°C for 1 hour to hydrolyze the methoxy groups. 10.0 parts by mass of tungsten carbide particles (manufactured by ALMT Corp., trade name "WC60S," average primary particle size 6.5 μm) were added to this solution. The mixture was cooled to a liquid temperature not exceeding 50°C using a homogenizer ("Excel auto homogenizer ED-7" manufactured by Nippon Seiki Co., Ltd.), stirred at 10,000 rpm for 60 minutes, and ground and surface treated.

[0391] The mixture stirred and pulverized in the above process was filtered, and the obtained solid matter was dried by heating at 100° C. for 30 minutes to obtain powdery surface-treated tungsten carbide particles (C-1) (component (C)).

[0392] In the preparation of surface-treated tungsten carbide particles (C-1), surface-treated tungsten carbide particles (C-2) to (C-30) were prepared in the same manner as surface-treated tungsten carbide particles (C-1), except that the raw materials had the composition shown in Table 1 below. Tables 1-1 to 1-6, described below, are collectively referred to as Table 1.

[0393] In the preparation of the surface-treated tungsten carbide particles (C-2) to (C-30), 10.0 parts by mass of the raw material tungsten carbide particles were used.

[0394] Furthermore, in the preparation of the surface-treated tungsten carbide particles (C-1), tungsten particles were used instead of tungsten carbide particles. As a result, the surface treatment was not sufficiently performed, resulting in aggregation and being unusable.

[0395] [Preparation Example] Preparation Example of Surface-treated Tungsten Carbide Particles (C-31)

[0396] Tungsten carbide particles (50 g) were added to a solution of NaOH (40 g NaOH / 400 ml water) and stirred. Sodium persulfate solution (9.6 g sodium persulfate / 100 ml water) was then added to the NaOH solution. The solution was then heated to 50°C and stirred for 3 hours (modification step). Stirring was performed at 150 rpm using a three-in-one motor manufactured by Shinto Scientific Co., Ltd.

[0397] After the NaOH water was cooled to room temperature, the tungsten carbide particles in the NaOH water were filtered out, and the filtered tungsten carbide particles were washed with water (500 ml) and acetonitrile (250 ml) to obtain modified tungsten carbide particles.

[0398] Surface-treated tungsten carbide particles (C-31) were prepared in the same manner as in the preparation of the surface-treated tungsten carbide particles (C-1), except that modified tungsten carbide particles were used instead of tungsten carbide particles.

[0399] Surface-treated tungsten carbide particles (C-32) to (C-48) were prepared in the same manner as for the surface-treated tungsten carbide particles (C-31), except that the raw materials had the composition shown in Table 1 below.

[0400] [Table 1]

[0401] Table 1-1

[0402]

[0403] Table 1-2

[0404]

[0405] Table 1-3

[0406]

[0407] [Table 2]

[0408] Table 1-4

[0409]

[0410] Table 1-5

[0411]

[0412] Table 1-6

[0413]

[0414] Notes

[0415] [Tungsten carbide particles (W)]

[0416] (W-1):

[0417] Untreated tungsten carbide particles (manufactured by ALMT Corp., trade name "WC30S", average primary particle size 3 μm)

[0418] (W-2):

[0419] Untreated tungsten carbide particles (manufactured by ALMT Corp., trade name "WC60S", average primary particle size 6.5 μm)

[0420] (W-3):

[0421] Untreated tungsten carbide particles (manufactured by ALMT Corp., trade name "WC80S", average primary particle size 9 μm)

[0422] (W-4):

[0423] Untreated tungsten carbide particles (manufactured by ALMT Corp., trade name "WC100S", average primary particle size 15 μm)

[0424] [Surface treatment agent (S)]

[0425] <Aminosilane compounds>

[0426] (SA-1):

[0427] 3-Aminopropyltrimethoxysilane (manufactured by Gelest, trade name "SIA0611.0")

[0428] Mercaptosilane compounds

[0429] (SM-1):

[0430] 3-Mercaptopropyltrimethoxysilane (manufactured by Gelest, trade name "SIM6476.0")

[0431] (SM-2):

[0432] 11-Mercaptoundecyltrimethoxysilane (manufactured by Gelest, trade name "SIM6480.0")

[0433] <Isocyanatosilane compounds>

[0434] (SI-1):

[0435] 3-Isocyanatopropyltrimethoxysilane (manufactured by Gelest, trade name "SII6456.0")

[0436] (SI-2):

[0437] Isocyanate methyltrimethoxysilane (manufactured by Gelest, trade name "SII6453.8")

[0438] <Titanium alkoxide compounds>

[0439] (ST-1):

[0440] Isopropyl triisostearyl titanate (manufactured by Ajinomoto Fine-Techno Co., Inc., trade name "PLENACT TTS")

[0441] [Chemical Formula 6]

[0442]

[0443] (ST-2):

[0444] Dioctylbis(ditridec phosphate) titanate ("PLENACT 46B" manufactured by Ajinomoto Fine-Techno Co., Inc.)

[0445] [Chemical Formula 7]

[0446]

[0447] (ST-3):

[0448] Isopropyl tris(N-aminoethyl-aminoethyl) titanate (manufactured by Ajinomoto Fine-Techno Co., Inc., trade name "PLENACT 44")

[0449] [Chemical Formula 8]

[0450]

[0451] <Aluminum alkoxide compounds>

[0452] (SL-1):

[0453] Aluminum tri-sec-butyrate (manufactured by Kawaken Fine Chemicals Co., Ltd., trade name "ASBD")

[0454] [Chemical Formula 9]

[0455]

[0456] (SL-2):

[0457] Aluminum triacetylacetonate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX AL-3100")

[0458] [Chemical Formula 10]

[0459]

[0460] (SL-3):

[0461] Ethyl bisacetoacetate and aluminum monoacetylacetonate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX AL-3200")

[0462] [Chemical Formula 11]

[0463]

[0464] (SL-4):

[0465] Aluminum triacetoacetate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX AL-3215")

[0466] [Chemical Formula 12]

[0467]

[0468] (SL-5):

[0469] Octadecylaluminum acetate diisopropyl acetate (manufactured by Ajinomoto Fine-Techno Co., Inc., trade name "PLENACT AL-M")

[0470] [Chemical Formula 13]

[0471]

[0472] <Zirconium alkoxide compounds>

[0473] (SZ-1):

[0474] Zirconium tetra-n-propoxide (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX ZA-45")

[0475] [Chemical Formula 14]

[0476]

[0477] (SZ-2):

[0478] Zirconium tetra-n-butoxide (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX ZA-65")

[0479] [Chemical Formula 15]

[0480]

[0481] (SZ-3):

[0482] Zirconium tetraacetylacetonate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX ZC-150")

[0483] [Chemical Formula 16]

[0484]

[0485] (SZ-4):

[0486] Zirconium ammonium lactate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX ZC-300")

[0487] [Chemical Formula 17]

[0488]

[0489] (SZ-5):

[0490] Tributyl zirconium stearate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX ZC-320")

[0491] [Chemical Formula 18]

[0492]

[0493] (SZ-6):

[0494] Zirconium tributoxymonoacetylacetonate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX ZC-540")

[0495] [Chemical Formula 19]

[0496]

[0497] (SZ-7):

[0498] Dibutoxybis(ethyl acetoacetate)zirconium (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "ORGATIX ZC-580")

[0499] [Chemical Formula 20]

[0500]

[0501] <Oxidants>

[0502] Sodium persulfate (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0503] Sodium hypochlorite (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0504] <Surface treatment agents used in comparative examples>

[0505] (SA-2):

[0506] N-Trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (manufactured by Gelest, trade name "SIT8415.0", 50% methanol aqueous solution)

[0507] (SC-1):

[0508] Methyltrichlorosilane

[0509] (SC-2):

[0510] Vinyltrichlorosilane

[0511] (SC-3):

[0512] 3-Methacryloxypropyltrimethoxysilane

[0513] <1> Preparation of materials for acoustic matching layer

[0514] (1) Preparation of the Acoustic Matching Layer Material Used in Example 1

[0515] 5.6 parts by mass of epoxy resin (component (A) in Table 2 below, bisphenol A diglycidyl ether ("jER825" (trade name), manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 170)), 1.4 parts by mass of isophorone diamine (component (B) in Table 2 below), and 93 parts by mass of the surface-treated tungsten carbide particles (C-1) (component (C) in Table 2 below) prepared in the above-mentioned Preparation Example were placed in a cylindrical container having an internal space with a diameter of 40 mm so that the thickness after mixing would be 3 mm. The mixture was then mixed using a rotation / revolution device (trade name: ARV-310, manufactured by THINKY CORPORATION) to prepare the acoustic matching layer material used in Example 1.

[0516] (2) Preparation of Acoustic Matching Layer Materials Used in Examples 2 to 60 and Comparative Examples 1 to 5

[0517] Acoustic matching layer materials used in Examples 2 to 60 and Comparative Examples 1 to 5 were prepared in the same manner as in Example 1, except that the compositions described in Table 2 below were used instead.

[0518] <2>Production of acoustic matching sheet

[0519] (1) Preparation of the Acoustic Matching Sheet of Example 1

[0520] The acoustic matching layer materials used in Example 1 were mixed, placed in the above-mentioned container, and cured at 80°C for 18 hours, followed by curing at 150°C for 1 hour. This produced a circular acoustic matching sheet with a diameter of 40 mm and a thickness of 3 mm. This sheet was cut into three circular acoustic matching sheets with a diameter of 40 mm and a thickness of 1 mm using a microtome. The center sheet (1 mm thick) was used in the test examples described below.

[0521] (2) Preparation of Acoustic Matching Sheets of Examples 2 to 60 and Comparative Examples 1 to 5

[0522] Acoustic matching sheets (thickness 1 mm) were prepared in the same manner as the acoustic matching sheet used in Example 1, except that the acoustic matching layer materials used in Examples 2 to 60 and Comparative Examples 1 to 5 were used instead of the acoustic matching layer material used in Example 1. These sheets were then used in the test examples described below.

[0523] <3>Production of reference sound matching sheet

[0524] A reference acoustic matching sheet used in the following [Test Example 2] was produced as follows.

[0525] (1) Preparation of reference acoustic matching sheet for evaluation of Example 1

[0526] A reference acoustic matching sheet (1 mm thick) for evaluation in Example 1 was prepared in the same manner as the acoustic matching sheet used in Example 1, except that 80 parts by mass of epoxy resin (component (A) in Table 2 below, bisphenol A diglycidyl ether ("jER825" (trade name) manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 170)) and 20 parts by mass of isophorone diamine (component (B) in Table 2 below) were used in place of the acoustic matching layer material used in Example 1. This sheet was then used in Test Example 2 described below.

[0527] (2) Preparation of Reference Acoustic Matching Sheets for Evaluation of Examples 2 to 60 and Comparative Examples 1 to 5

[0528] Reference acoustic matching sheets for use in the evaluation of Examples 2 to 60 and Comparative Examples 1 to 5 were prepared in the same manner as the reference acoustic matching sheet for use in the evaluation of Example 1, except that the blending ratio of the epoxy resin to the curing agent was replaced with the blending ratio described in Table 1.

[0529] [Test Example 1] Measurement of sound velocity

[0530] The ultrasonic sound velocity was measured at 25°C using a sing-around sound velocity measuring device (manufactured by ULTRASONIC ENGINEERING CO., LTD., trade name "UVM-2") in accordance with JIS Z2353 (2003). With respect to the circular acoustic matching sheet with a diameter of 40 mm and a thickness of 1 mm obtained above, three circular areas with a diameter of 1.5 cm that do not overlap with each other were used as the internal whole of the three circular areas (mono-channel small probe size) as the measurement object. The arithmetic mean of the sound velocity of the above three circular areas was calculated, and the sound velocity reduction rate (%) obtained from the following formula was applied to the following evaluation criteria for evaluation. In this test, S to D were qualified. The results are recorded in the following Table 2. In addition, Tables 2-1 to 2-7 described below are collectively referred to as Table 2.

[0531] Sound velocity reduction rate (%) = 100 × (arithmetic mean of the sound velocity of the reference sound matching sheet - arithmetic mean of the sound velocity of the sound matching sheet of the embodiment or comparative example) / arithmetic mean of the sound velocity of the reference sound matching sheet

[0532] -Evaluation Criteria-

[0533] S: less than 5%

[0534] A: 5% or more and less than 7%

[0535] B: 7% or more and less than 9%

[0536] C: 9% or more and less than 11%

[0537] D: 11% or more and less than 13%

[0538] E: 13% or more and less than 15%

[0539] F: more than 15%

[0540] [Test Example 2] Changes in Acoustic Impedance (AI)

[0541] A 10 mm × 10 mm test piece was cut out from each sound velocity measurement object (circle with a diameter of 1.5 cm) of the above-mentioned Test Example 1. The density of the test piece at 25°C was measured using an electronic hydrometer (manufactured by Alfa Mirage Co., Ltd., trade name "SD-200L") in accordance with the density measurement method of Method A (displacement in water) described in JIS K7112 (1999). For the acoustic matching sheet of each embodiment and comparative example, the acoustic impedance (density × sound velocity) of each of the three circular areas was calculated and the standard deviation of the three acoustic impedances was obtained, and the changes in the acoustic characteristics were evaluated by applying them to the following evaluation criteria. In this test, A to C were qualified. The results are recorded in Table 2 below.

[0542] -Evaluation Criteria-

[0543] A: less than 0.5 Mrayl

[0544] B: 0.5 Mrayl or more and less than 0.6 Mrayl

[0545] C: 0.6 Mrayl or more and less than 0.7 Mrayl

[0546] D: 0.7 Mrayl or more and less than 1 Mrayl

[0547] E: 1Mrayl or more

[0548] [Table 3]

[0549] Table 2-1

[0550]

[0551] Table 2-2

[0552]

[0553] [Table 4]

[0554] Table 2-3

[0555]

[0556] Table 2-4

[0557]

[0558] [Table 5]

[0559] Table 2-5

[0560]

[0561] [Table 6]

[0562] Table 2-6

[0563]

[0564] Table 2-7

[0565]

[0566] Notes

[0567] "EX": Example

[0568] "CEX": Comparative Example

[0569] Particle size: average primary particle size

[0570] "php": 100 × parts by mass of surface treatment agent / 100 parts by mass of tungsten carbide particles

[0571] For comparison with W-2 (untreated tungsten carbide particles), Comparative Example 1 is described in the row of ingredient (C).

[0572] [Epoxy resin]

[0573] (A-1): Bisphenol A diglycidyl ether ("jER825" (trade name) manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 170)

[0574] (A-2): Bisphenol F diglycidyl ether ("EPICLON 830" (trade name) manufactured by DIC Corporation, epoxy equivalent 170)

[0575] (A-3): Epoxy novolac resin (manufactured by Sigma-Aldrich Co. LLC, product number 406775, epoxy equivalent weight 170)

[0576] (B-1):

[0577] Isophorone diamine

[0578] (B-2):

[0579] Triethylenetetramine

[0580] (B-3):

[0581] 2,4,6-Tris(dimethylaminomethyl)phenol (manufactured by Nacalai Tesque Inc., trade name "LUVEAK DMP-30")

[0582] (B-4):

[0583] Polyamidoamine (manufactured by DIC Corporation, trade name "LUCKAMIDE EA-330")

[0584] (B-5):

[0585] diphenylmethanediamine

[0586] (B-6):

[0587] m-phenylenediamine

[0588] (B-7):

[0589] Polyetheramine T-403 (trade name, manufactured by BASF)

[0590] (B-8):

[0591] 2-Ethyl-4-methylimidazole

[0592] (B-9):

[0593] Hexahydrophthalic anhydride (manufactured by New Japan Chemical Co., Ltd., trade name "RIKACID HH")

[0594] As shown in Table 2, the acoustic matching sheet of Comparative Example 1 using untreated tungsten carbide particles had a significant decrease in sound velocity and a large change in AI.

[0595] The acoustic matching sheet of Comparative Example 2 using tungsten carbide particles surface-treated with methyltrichlorosilane exhibited a significant decrease in sound velocity and a large change in AI because the particles had poor compatibility when mixed with epoxy resin and heat generated a sheet in which the particles were unevenly dispersed.

[0596] The acoustic matching sheet of Comparative Example 3 using tungsten carbide particles surface-treated with vinyltrichlorosilane and the acoustic matching sheet of Comparative Example 4 using tungsten carbide particles surface-treated with 3-methacryloxypropyltrimethoxysilane showed a significant decrease in sound velocity and a large change in AI for the same reasons as Comparative Example 2.

[0597] In contrast, it was found that the acoustic matching sheets of Examples 1 to 60 using the surface-treated tungsten carbide particles specified in the present invention were able to effectively suppress the decrease in sound velocity and also suppress changes in acoustic characteristics.

[0598] Furthermore, the acoustic matching sheets of Examples 1 to 60 all had AI sufficient to function as an acoustic matching layer on the piezoelectric element side.

[0599] Explanation of symbols

[0600] 1-Acoustic lens, 2-Acoustic matching layer, 3-Piezoelectric element layer, 4-Backing material, 7-Shell, 9-Cord, 10-Ultrasonic probe (probe).

Claims

1. A material for an acoustic matching layer, comprising the following components (A), (B) and (C), (A) Epoxy resin (B) Curing agent (C) Surface-treated tungsten carbide particles surface-treated with a surface treatment agent comprising at least one of an aminosilane compound, a mercaptosilane compound, an isocyanatosilane compound, a thiocyanatosilane compound, a zirconium alkoxide compound, and a titanium alkoxide compound.

2. The acoustic matching layer material according to claim 1, wherein The component (B) contains at least one of a primary amine and a secondary amine.

3. The acoustic matching layer material according to claim 1 or 2, wherein: The surface treatment agent includes at least one of an aminosilane compound, a zirconium alkoxide compound, and a titanium alkoxide compound.

4. The acoustic matching layer material according to claim 1 or 2, wherein: The surface treatment agent includes at least one of a zirconium alkoxide compound and a titanium alkoxide compound.

5. The acoustic matching layer material according to claim 1 or 2, wherein: The surface treatment agent includes the zirconium alkoxide compound, and the zirconium alkoxide compound contains at least one of an acetonate structure and an acetate structure.

6. The acoustic matching layer material according to claim 1 or 2, wherein: The surface treatment agent includes the zirconium alkoxide compound, and the zirconium alkoxide compound includes at least one compound represented by the following general formula (2), General formula (2): R 1 bm2-Zr-(OR 2 b)4-m2 R 1 b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group or an unsaturated aliphatic group, R 2 b represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group or -SO2R S2 , R S2 represents a substituent, m2 is an integer from 0 to 3.

7. The acoustic matching layer material according to claim 1 or 2, wherein: The surface treatment agent includes the titanium alkoxide compound, and the titanium alkoxide compound contains at least one atom of nitrogen, phosphorus, and sulfur.

8. The acoustic matching layer material according to claim 1 or 2, wherein: The surface treatment agent includes the titanium alkoxide compound, and the titanium alkoxide compound includes at least one compound represented by the following general formula (3), General formula (3): R 1 cm3-Ti-(OR 2 c)4-m3 R 1 c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an aryl group or an unsaturated aliphatic group, R 2 c represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, an alkenyl group, an aryl group, a phosphonate group or -SO2R S3 , R S3 represents a substituent, m3 is an integer from 0 to 3.

9. The acoustic matching layer material according to claim 1 or 2, wherein: In the component (C), the content of the surface treatment agent is 1 to 50 parts by mass based on 100 parts by mass of the tungsten carbide particles.

10. The acoustic matching layer material according to claim 1 or 2, wherein: The average primary particle size of the tungsten carbide particles constituting the component (C) is 1 to 10 μm. 11 . An acoustic matching sheet, which is formed by curing the acoustic matching layer material according to claim 1 . 12 . An acoustic wave probe comprising the acoustic matching sheet according to claim 11 . 13 . An ultrasonic probe comprising the acoustic matching sheet according to claim 11 . 14 . An acoustic wave measuring device comprising the acoustic wave probe according to claim 12 . 15 . An ultrasonic diagnostic apparatus comprising the ultrasonic probe according to claim 13 .

16. A method for manufacturing an acoustic wave probe, comprising: A step of forming an acoustic matching layer using the acoustic matching layer material according to any one of claims 1 to 10.

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