JP2018195964A - Resin for acoustic wave probe, resin material for acoustic wave probe, production method of resin material for acoustic wave probe, acoustic lens, acoustic wave probe, ultrasonic probe, acoustic wave measuring device, ultrasonic diagnostic equipment, photoacoustic wave measuring device and ultrasonic endoscope - Google Patents

Abstract

To provide a resin for an acoustic wave probe and a resin material for an acoustic wave probe capable of providing, by being molded, a constituent member of an acoustic wave probe whose acoustic impedance is close to the value of a living body, the acoustic wave attenuation amount is reduced, and the chemical resistance is excellent, and a production method of the resin material for an acoustic wave probe, and to provide an acoustic lens, an acoustic wave probe, an ultrasonic probe, an acoustic wave measuring device, an ultrasonic diagnostic device, a photoacoustic wave measuring device, and an ultrasonic endoscope.SOLUTION: The resin material for an acoustic wave probe contains: a resin for an acoustic wave probe containing a specific vinyl polymer, a polysiloxane, an organic peroxide and/or a photo radical polymerization initiator; and a resin formed by bonding a specific vinyl polymer and polysiloxane to each other.SELECTED DRAWING: None

Description

  The present invention relates to a resin for an acoustic wave probe, a resin material for an acoustic wave probe, a method for producing a resin material for an acoustic wave probe, an acoustic lens, an acoustic wave probe, an ultrasonic probe, an acoustic wave measuring device, an ultrasonic diagnostic device, and a photoacoustic device. The present invention relates to a wave measuring device and an ultrasonic endoscope.

  In an acoustic wave measuring apparatus, an acoustic wave probe that irradiates an object to be examined or a part (hereinafter also simply referred to as an object), receives a reflected wave (echo), and outputs a signal is used. The electric signal converted from the reflected wave received by the acoustic wave probe is displayed as an image. Thereby, the inside of the test object is visualized and observed.

As the acoustic wave, one having an appropriate frequency such as an ultrasonic wave and a photoacoustic wave is selected according to a test object and / or measurement conditions.
For example, the ultrasonic diagnostic apparatus transmits an ultrasonic wave toward the inside of the subject, receives the ultrasonic wave reflected by the tissue inside the subject, and displays it as an image. The photoacoustic wave measuring apparatus receives an acoustic wave radiated from the inside of the subject to be examined by the photoacoustic effect and displays it as an image. The photoacoustic effect means that when a test object is irradiated with an electromagnetic pulse such as visible light, near-infrared light, or microwave, the test object absorbs the electromagnetic wave, generates heat, and thermally expands. This is a phenomenon in which ultrasonic waves are typically generated.
Since the acoustic wave measuring device transmits and receives acoustic waves to and from a living body to be examined, requirements such as acoustic impedance matching with a living body (typically a human body) and reduction of acoustic wave attenuation are required. It is required to satisfy.

For example, a probe for an ultrasonic diagnostic apparatus (also referred to as an ultrasonic probe), which is a kind of acoustic wave probe, includes a piezoelectric element that transmits and receives ultrasonic waves, an acoustic lens that is a part that comes into contact with a living body, and a piezoelectric element. And an acoustic matching layer positioned between the acoustic lens and the acoustic lens. The ultrasonic wave oscillated from the piezoelectric element passes through the acoustic matching layer and the acoustic lens and enters the living body.
The acoustic matching layer has an acoustic impedance closer to the piezoelectric element on the acoustic element side, and an acoustic impedance closer to the acoustic lens on the acoustic lens side, from the point of effectively transmitting and receiving ultrasonic waves to and from the test object. Is required. For example, Patent Document 1 discloses that at least one matching material is thermosetting as a method of manufacturing an ultrasonic terminal capable of preventing damage to the matching material in the bonding process of the matching material constituting the acoustic matching layer having the above characteristics. An ultrasonic terminal manufacturing method is described in which two or more matching materials, each composed of a resin and a filler, are bonded with an adhesive having a viscosity at 25 ° C. of 10 Pa · s or less.

In addition, when the difference between the acoustic impedance (density × sound speed) of the acoustic lens and the acoustic impedance of the living body is large, the ultrasonic wave is reflected on the surface of the living body, so that the ultrasonic wave is not efficiently incident on the living body. Therefore, it is difficult to obtain a good resolution. In order to transmit and receive ultrasonic waves with high sensitivity, it is desired that the acoustic lens has a small ultrasonic attenuation.
For this reason, as one of the materials of the acoustic lens, a silicone resin that is close to the acoustic impedance of a living body (1.4 to 1.7 × 10 ⁶ kg / m ² / sec in the case of a human body) and has a small ultrasonic attenuation amount is used. It is used. Further, the ultrasonic probe is used repeatedly. Therefore, in particular, an acoustic lens that comes into contact with a subject to be examined needs to be sterilized with a chemical every time it is used, and chemical resistance is required.

JP 2014-168489 A

In Patent Document 1, as an example of an acoustic lens, an acoustic lens obtained by mixing silicone rubber and butadiene rubber and vulcanizing and curing is described.
However, at a higher level required for acoustic wave probes in recent years, the acoustic lens described in Patent Document 1 requires further improvement in terms of reduction of acoustic impedance and acoustic wave attenuation. Further, with respect to chemical resistance, there is an increasing demand from the viewpoint of performance guarantee in actual use and further improvement of the service life. However, since the acoustic lens described in Patent Document 1 has a diene structure that easily oxidizes in the rubber component, the chemical resistance is insufficient.

In view of the above situation, the present invention is a component of an acoustic wave probe (for example, an acoustic lens and an acoustic matching layer) in which the acoustic impedance is close to that of a living body, the acoustic attenuation is reduced, and the chemical resistance is excellent. It is an object to provide a resin material for an acoustic wave probe and a method for producing the resin material for an acoustic wave probe.
Moreover, this invention makes it a subject to provide resin for acoustic wave probes which can be used for preparation of said resin material for acoustic wave probes.
Moreover, this invention makes it a subject to provide the acoustic lens which consists of said resin material for acoustic wave probes.
In addition, the present invention provides an acoustic wave probe, an ultrasonic probe, an acoustic wave measuring device, an ultrasonic diagnostic device, a photoacoustic wave measuring device, and an ultrasonic wave, each having a constituent material manufactured using the resin material for an acoustic wave probe. It is an object to provide an endoscope.

The above problem has been solved by the following means.
<1>
A resin for an acoustic wave probe comprising a vinyl polymer (A), a polysiloxane (B), an organic peroxide (C1) and / or a radical photopolymerization initiator (C2),
The vinyl polymer (A) is polyethylene, polypropylene, polymethylpentene, poly (meth) acrylic acid ester, polyvinyl chloride, chlorinated polyethylene, ethylene- (meth) acrylic acid ester copolymer, ethylene-vinyl acetate. A resin for an acoustic wave probe selected from a copolymer, polystyrene, and an acrylonitrile-styrene copolymer.
<2>
A resin material for an acoustic wave probe comprising a resin in which a vinyl polymer (A) and a polysiloxane (B) are bonded to each other,
The vinyl polymer (A) is polyethylene, polypropylene, polymethylpentene, poly (meth) acrylic acid ester, polyvinyl chloride, chlorinated polyethylene, ethylene- (meth) acrylic acid ester copolymer, ethylene-vinyl acetate. A resin material for an acoustic wave probe selected from a copolymer, polystyrene, and an acrylonitrile-styrene copolymer.
<3>
<2> The mass ratio of the polysiloxane (B) to the vinyl polymer (A) is vinyl polymer (A): polysiloxane (B) = 1: 99 to 99: 1. Resin material for acoustic wave probes.
<4>
The resin material for an acoustic wave probe according to <2> or <3>, wherein the vinyl polymer (A) and the polysiloxane (B) are thermally melted.
<5>
<2> to <4>, in which the sound velocity at 25 ° C. is 1,800 m / s or less and the acoustic impedance is 1.20 × 10 ^{6 to} 1.80 × 10 ⁶ kg / m ² / s. The resin material for an acoustic wave probe according to any one of the above.
<6>
The acoustic wave according to <5>, in which the sound velocity at 25 ° C. is 1,600 m / s or less and the acoustic impedance is 1.30 × 10 ^{6 to} 1.70 × 10 ⁶ kg / m ² / s. Resin material for probes.
<7>
A step of reacting the melted vinyl polymer (A) with the polysiloxane (B) using an organic peroxide (C1) and / or a photoradical polymerization initiator (C2), <2 The manufacturing method of the resin material for acoustic wave probes as described in any one of>-<6>.
<8>
<2>-<6> The acoustic lens which consists of a resin material for acoustic wave probes as described in any one of.
<9>
<2>-<6> The acoustic wave probe which has an acoustic lens and / or acoustic matching layer which consist of the resin material for acoustic wave probes as described in any one of.
<10>
An ultrasonic probe comprising a capacitive micromachine ultrasonic transducer as an ultrasonic transducer array and the acoustic lens according to <8>.
<11>
An acoustic wave measuring apparatus provided with the acoustic wave probe as described in <9>.
<12>
An ultrasonic diagnostic apparatus comprising the acoustic wave probe according to <9>.
<13>
A photoacoustic wave measurement apparatus comprising the acoustic lens according to <8>.
<14>
An ultrasonic endoscope comprising the acoustic lens according to <8>.

In this specification, when there are a plurality of substituents, linking groups, repeating structures, etc. (hereinafter referred to as substituents, etc.) indicated by a specific symbol, or when a plurality of substituents etc. are specified simultaneously, there is a special notice. As long as there is no, each substituent etc. may mutually be same or different. The same applies to the definition of the number of substituents and the like. Further, when a plurality of substituents and the like are close to each other (especially when they are adjacent to each other), they may be connected to each other to form a ring unless otherwise specified. Further, a ring such as an aliphatic ring, an aromatic ring, or a hetero ring may be further condensed to form a condensed ring.
In the present specification, when the number of carbon atoms of a certain group is defined, this number of carbons means the total number of carbon atoms in the group. That is, when this group is a form further having a substituent, it means the total number of carbon atoms including this substituent.
Moreover, the group (for example, alkyl group) specified by each group may further have a substituent. Further, “Si—H group” means a group having three bonds in addition to —H on a silicon atom, but the description of these bonds is omitted and the notation is simplified.
In this specification, “(meth) acryl” means acrylic and / or methacrylic. Similarly, “(meth) acryloyl” means acryloyl and / or methacryloyl, “(meth) acrylate” means acrylate and / or methacrylate, and “(meth) acrylic acid” means , Acrylic acid and / or methacrylic acid.
In this specification, when the repeating unit constituting the polymer may take a plurality of repeating units, these repeating units may be the same or different. Taking an ethylene-α-olefin copolymer as an example, the α-olefin component constituting the ethylene-α-olefin copolymer may be one type alone or two or more types. Further, the form of the copolymer is not limited, and any of a random polymer, a block polymer, and a graft polymer may be used.
Further, in the present specification, “to” is used in the sense of including the numerical values described before and after it as the lower limit and the upper limit.

In addition, unless otherwise indicated, the mass average molecular weight in this specification is a measurement value (polystyrene conversion) of gel permeation chromatography (GPC).
Specifically, the GPC apparatus HLC-8220 (manufactured by Tosoh Corporation) is prepared, the tetrahydrofuran (Wako Pure Chemical Industries, Ltd.) is used as an eluent, and TSKgel (registered trademark) G3000HXL + TSKgel (registered) is used as a column. (Trademark) G2000HXL can be used and measured using an RI detector under conditions of a temperature of 23 ° C. and a flow rate of 1 mL / min.

  The structural member of the acoustic wave probe produced using the resin material for acoustic wave probes of the present invention has an acoustic impedance close to that of a living body, a reduced acoustic wave attenuation, and excellent chemical resistance. Moreover, according to the manufacturing method of the resin material for acoustic wave probes of this invention, the resin material for acoustic wave probes which has the said outstanding performance can be provided. In addition, the component of the acoustic wave probe produced using the acoustic wave probe resin material prepared using the acoustic wave probe resin of the present invention has an acoustic impedance close to that of a living body, and the acoustic wave attenuation is reduced. Excellent chemical resistance. In addition, the acoustic lens, acoustic wave probe, ultrasonic probe, acoustic wave measuring device, ultrasonic diagnostic device, photoacoustic wave measuring device, and ultrasonic endoscope of the present invention have the above-mentioned excellent performance. A constituent member manufactured using a material is included.

It is a perspective transmissive view about an example of a convex type ultrasonic probe which is one mode of an acoustic wave probe.

<< Resin material for acoustic wave probe >>
The resin material for acoustic wave probes of the present invention contains a resin in which a specific vinyl polymer (A) and polysiloxane (B) are bonded to each other. Hereinafter, the “resin material for acoustic wave probes” is also simply referred to as “resin material”. The “resin in which the vinyl polymer (A) and the polysiloxane (B) are bonded to each other” is also simply referred to as “composite resin”.
The resin material for an acoustic wave probe of the present invention may be in the form of a composite resin, or in addition to the composite resin, filler, catalyst, solvent, dispersant, pigment, dye, antistatic agent, flame retardant, thermal conductivity improvement It may be in a form containing a conventional component or an optional component that exhibits an additional action such as an agent, and the residue of the organic peroxide (C1) and / or the radical photopolymerization initiator (C2) is removed. The form to contain may be sufficient. Furthermore, the resin material for acoustic wave probes of the present invention may contain a vinyl polymer (A) and / or a polysiloxane (B) that are not bonded to each other as long as the effects of the present invention are exhibited. . When the resin material for an acoustic wave probe of the present invention is composed of two or more kinds of components, it is usually preferable to have a composition form in which the respective components are uniformly mixed.
The shape of the resin material for acoustic wave probes of the present invention is not particularly limited. It may be mixed with a solvent or the like to have fluidity, or may be in the form of pellets.

The resin material for an acoustic wave probe of the present invention is formed into the shape of a constituent member of the acoustic wave probe (for example, a sheet shape), so that the acoustic impedance, chemical resistance and acoustic wave attenuation close to those of a living body are obtained. It can be set as the structural member of the acoustic wave probe excellent in any characteristic of quantity reduction. The reason is estimated, but for acoustic impedance close to the value of the living body, by using a combination of a specific vinyl polymer (A) and polysiloxane (B), the characteristics of both, particularly the sound speed and specific gravity, can be reduced. It is considered that it can act in a complex manner and obtain an acoustic impedance close to that of a living body. Further, it is considered that the reduction of the acoustic wave attenuation contributes to the reduction of each dispersion size by creating a bonded state between the vinyl polymer (A) and the polysiloxane (B). The vinyl polymer (A) and the polysiloxane (B) usually have low compatibility and are difficult to mix and homogenize. Further, even if mixing is possible to some extent, acoustic wave attenuation is caused by acoustic wave scattering that is considered to be caused by phase separation. In the present invention, when a specific vinyl polymer (A) and a polysiloxane (B) are combined, the compatibility between the two is improved, and the respective dispersion sizes are reduced, so that acoustic wave scattering is achieved. Is suppressed, and effective reduction of the acoustic wave attenuation is realized. In addition, the above improvement in compatibility promotes the formation of a dense cross-linked structure of the composite resin, and as a result, the entry of chemicals between the two is suppressed, and it is considered that excellent chemical resistance can be realized. It is done. These actions are considered to be further improved by bonding the specific polymer (A) and the polysiloxane (B) through thermal melting.
Hereinafter, the resin sheet obtained from the resin material for acoustic wave probes of the present invention is also referred to as “resin sheet for acoustic wave probes” to “resin sheet”.

1. Composite resin in which vinyl polymer (A) and polysiloxane (B) are bonded to each other The composite resin contained in the resin material of the present invention is a combination of vinyl polymer (A) and polysiloxane (B) in each other. As long as it is a compound obtained, it is not particularly limited.

(1) Vinyl polymer (A)
The vinyl polymer (A) in the present invention is polyethylene, polypropylene, polymethylpentene, poly (meth) acrylate, polyvinyl chloride, chlorinated polyethylene, ethylene- (meth) acrylate copolymer, ethylene- It is selected from vinyl acetate copolymer, polystyrene, and acrylonitrile-styrene copolymer.
Hereinafter, the details of each vinyl polymer (A) will be described.

(polyethylene)
In the present invention, polyethylene is obtained by grafting ethylene homopolymer, copolymer of α-olefin and ethylene, silane-modified resin of these polymers and other chemical species to these polymers. Modified resins obtained. However, the polyethylene does not include a copolymer with ethylene described as propylene, polymethylpentene, polyvinyl chloride, chlorinated polyethylene, polystyrene, and acrylonitrile-styrene copolymer, which will be described later. In the said polyethylene, 80-100 mass% is preferable and, as for content of an ethylene component, 90-100 mass% is more preferable.
The α-olefin preferably has 3 to 20 carbon atoms. For example, propylene, 1-butene, isobutylene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, Examples include 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene and 1-decene.
The polyethylene is preferably an ethylene homopolymer or a copolymer of an α-olefin and ethylene.

Although polyethylene is not particularly limited, specifically, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ultra low density polyethylene (ULDPE), and linear low A density polyethylene (LLDPE) etc. are mentioned. Polyethylene (LDPE, ULDPE, or LLDPE) having a low density is preferable because transparency and flexibility are good.
The density of the polyethylene is preferably 0.900~0.940g / cm ^3, the density is more preferably LLDPE of 0.900~0.920g / cm ^3. When LLDPE having a density in the above range is used, a resin material for an acoustic wave probe capable of obtaining an acoustic impedance closer to that of a living body is obtained.
Further, since the speed of sound and acoustic impedance can be arbitrarily adjusted by changing the ratio with the polysiloxane (B), a polyethylene having a low density and a polyethylene having a high density may be used in combination.

As said LLDPE, the random copolymer of ethylene and an alpha olefin is mentioned preferably. As the α-olefin, the description of the α-olefin is preferably applied. In the present invention, from the viewpoint of industrial availability, mechanical properties such as hardness and strength, heat resistance, economy, etc., the α-olefin is 1-butene, 1-hexene or 1-octene. preferable.
In the ethylene-α-olefin random copolymer, the content of the α-olefin component is usually 2 mol% or more, and the preferable upper limit is 40 mol% or less, more preferably 3 to 30 mol%. More preferably, it is 5 to 25 mol%. If it is in the said range, since crystallinity will be reduced with an alpha olefin structural component and an acoustic wave attenuation amount will reduce, it is preferable.

The type and content of the α-olefin in the ethylene-α-olefin random copolymer can be qualitatively quantitatively analyzed by a conventional method, for example, using a nuclear magnetic resonance (NMR) measuring device or other instrumental analyzer. it can. The same applies to the types and contents of other copolymers described in the present specification.
The steric structure, branching, branching degree distribution and molecular weight distribution of the ethylene-α-olefin random copolymer are not particularly limited. For example, a copolymer having a long chain branch is a resin for acoustic wave probes. There are advantages such as increasing the strength of the material and lowering the melt viscosity to facilitate molding. A copolymer having a narrow molecular weight distribution polymerized using a single site catalyst has advantages such as a low low molecular weight component and relatively low blocking of raw material pellets.
The method for producing the ethylene-α-olefin random copolymer is not particularly limited, and a conventional method such as a polymerization method using a conventional olefin polymerization catalyst can be employed. For example, a slurry polymerization method, a solution polymerization method, a bulk polymerization method and a gas phase using a multi-site catalyst typified by a Ziegler-Natta type catalyst, or a single site catalyst typified by a metallocene catalyst and a post metallocene catalyst. Examples thereof include a polymerization method and a bulk polymerization method using a radical initiator.
Of these, LLDPE, LDPE, or HDPE is preferable as the polyethylene.

(polypropylene)
Polypropylene may be used as long as it is generally used for molding materials. For example, propylene homopolymer, random or block copolymer of propylene and ethylene and / or α-olefin (for example, ethylene-propylene random). Examples thereof include a copolymer and an ethylene-propylene block copolymer, and the content of the propylene component in the copolymer is preferably 20 to 90% by mass, more preferably 40 to 80% by mass.
As the polypropylene homopolymer, any of isotactic, atactic, syndiotactic and the like can be used.
The polypropylene is preferably a modified polypropylene modified with an α, β-unsaturated carboxylic acid or a derivative thereof from the viewpoint of improving compatibility with the polysiloxane (B), and the polypropylene in the resin material for an acoustic wave probe is preferably used. The dispersion size can be finely controlled.
Examples of the α, β-unsaturated carboxylic acid used herein include acrylic acid, methacrylic acid, maleic acid, itaconic acid, citraconic acid, hymic acid, bicyclo [2.2.2] oct-5-ene-2,3. -Dicarboxylic acid, 1,2,3,4,5,8,9,10-octahydronaphthalene-2,3-dicarboxylic acid, bicyclo [2.2.2] oct-7-ene-2,3,5 , 6-tetradicarboxylic acid, 7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid, and the like.
In addition, the derivatives of α, β-unsaturated carboxylic acids include acid anhydrides, esters, amides, imides and metal salts, such as maleic anhydride, itaconic anhydride, citraconic anhydride, hymic anhydride, maleic acid. Monomethyl ester, fumaric acid monomethyl ester, dimethylaminoethyl methacrylate, dimethylaminopropylacrylamide, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-N, N-diethylamide, maleic acid-N-monobutylamide, maleic Acid-N, N-dibutyramide, fumaric acid-N, N-dibutyramide, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, methyl acrylate, Examples include methyl tacrylate, ethyl acrylate, ethyl methacrylate, acrylic acid-n-butyl, methacrylic acid-n-hexyl, and cyclohexyl methacrylate.
Maleic anhydride is preferably used.
As polypropylene, propylene homopolymer or maleic anhydride-modified polypropylene is preferable.

(Polymethylpentene)
Polymethylpentene is a polymer mainly composed of 4-methyl-1-pentene obtained by dimerization of propylene. Specifically, the main component means that the component occupies 70% by mass or more of the total components. If necessary, it can be polymethylpentene copolymerized or graft-polymerized with other constituents (α-olefin, styrene, etc.) less than 30% by mass.
Polymethylpentene particularly useful in the present invention is a homopolymer of 4-methyl-1-pentene and less than 30% by weight of ethylene, propylene, 1-butene, 1-hexene, isobutylene or styrene and 70% by weight or more. It is a copolymer with 4-methyl-1-pentene.
In the copolymer, the content of 4-methyl-1-pentene component is preferably 70 to 100% by mass, and more preferably 80 to 100% by mass.
The polymethylpentene is preferably a modified polymethylpentene modified with an α, β-unsaturated carboxylic acid or a derivative thereof from the viewpoint of improving compatibility with the polysiloxane (B), and a resin material for an acoustic wave probe It is possible to finely control the dispersion size of the polymethylpentene inside.
As the α, β-unsaturated carboxylic acid and its derivative used here, the description of the α, β-unsaturated carboxylic acid and its derivative in the polypropylene is preferably applied.
As the polymethylpentene, a homopolymer of 4-methyl-1-pentene or a methyl methacrylate- (4-methyl-1-pentene) copolymer is preferable.

(Poly (meth) acrylic acid ester)
As poly (meth) acrylic acid ester, for example, (meth) acrylic acid and / or alkyl (meth) acrylate is the main constituent (preferably the content of the alkyl (meth) acrylate constituent is 50 to 100 mass. %) Homopolymers and copolymers. The alkyl group in the alkyl (meth) acrylate component preferably has 1 to 20 carbon atoms, specifically, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, 2-ethylhexyl or cyclohexyl is preferred.
Other structural components in the poly (meth) acrylic acid ester include, for example, (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide (the alkyl group in N-alkyl includes the above alkyl The alkyl group in the (meth) acrylate constituent component is preferably applied.), N-alkoxy (meth) acrylamide, N, N-dialkoxy (meth) acrylamide (the number of carbon atoms of the alkoxy group in N-alkoxy is 1-20. Preferable examples include methoxy, ethoxy, butoxy, isobutoxy and the like.) Amide group-containing monomers such as N-methylol (meth) acrylamide and N-phenyl (meth) acrylamide; 2-hydroxyethyl (meth) acrylate And 2-hydr Kishipuropiru (meth) hydroxyl group-containing monomers such as acrylate; glycidyl (meth) acrylate and (meth) acrylate components, such as glycidyl group-containing monomers such as allyl glycidyl ether.
Other constituents in the poly (meth) acrylic acid esters other than the above include vinyl isocyanate, allyl isocyanate, styrene, α-methyl styrene, vinyl methyl ether, vinyl ethyl ether, maleic acid, alkyl maleic acid monoester, fumarate. Constituent components such as acid, alkyl fumaric acid monoester, itaconic acid, alkyl itaconic acid monoester, (meth) acrylonitrile, vinylidene chloride, ethylene, propylene, vinyl chloride, vinyl acetate and the like can also be mentioned.
The poly (meth) acrylic acid ester may be an oily or aqueous or water dispersible resin. However, poly (meth) acrylic acid ester excludes the ethylene- (meth) acrylic acid ester copolymer described later.
Especially, as a poly (meth) acrylic acid ester, polymethyl methacrylate is preferable.

(PVC)
Examples of polyvinyl chloride include homopolymers and copolymers having vinyl chloride as a constituent component.
Examples of the vinyl chloride copolymer include a graft copolymer of vinyl chloride and ethylene-vinyl acetate, ethylene-ethyl acrylate, chlorinated polyethylene and / or polyurethane, and vinyl chloride, ethylene, propylene and / or Or a copolymer with vinyl acetate etc. is mentioned. The vinyl chloride copolymer preferably contains vinyl chloride as a main component (preferably occupying 80% by mass or more of all components).
When using polyvinyl chloride, it is also preferable to use a plasticizer in combination.
Although not particularly limited, the polymerization degree of polyvinyl chloride is preferably 800 or more from the viewpoint of excellent molding processability to components of an acoustic wave probe such as an ultrasonic probe and excellent mechanical strength. Further, from the viewpoint of suppressing the decrease in the mixing property between polyvinyl chloride and other components, the polymerization degree of polyvinyl chloride is preferably 2800 or less, and more preferably 1300 to 2500.
The plasticizer is preferably blended within a range of 10 to 20 parts by mass with respect to 100 parts by mass of polyvinyl chloride. When the blending amount of the plasticizer is less than 10 parts by mass, the moldability of the acoustic wave probe resin material tends to be reduced. On the other hand, when the plasticizer exceeds 20 parts by mass, the mechanical strength of the resin material for acoustic wave probes tends to decrease.
The plasticizer is preferably a phthalate ester plasticizer, a trimellitic ester plasticizer, a pyromellitic ester plasticizer or an aliphatic ester plasticizer. By using the plasticizer, a good plasticizing effect can be obtained when the resin material for an acoustic wave probe is manufactured or processed.
Examples of the alcohol constituting the phthalate ester plasticizer include saturated aliphatic alcohols having 8 to 13 carbon atoms. More specifically, the phthalate ester plasticizer includes, for example, di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate, dinonyl phthalate, diisodecyl phthalate, ditridecyl phthalate, and the like. be able to.
Examples of the alcohol constituting the trimellitic acid ester plasticizer and the pyromellitic acid ester plasticizer include saturated aliphatic alcohols having 8 to 13 carbon atoms.
Examples of the aliphatic ester plasticizer include adipic acid ester, sebacic acid ester, and azelaic acid ester. As alcohol which comprises ester, C3-C13 saturated aliphatic alcohol etc. can be mentioned. Examples of the aliphatic ester plasticizer include dioctyl adipate, isononyl adipate, dibutyl sebacate, dioctyl sebacate, dioctyl azelate, and the like.
As the polyvinyl chloride, a compound in which an aliphatic ester plasticizer is blended with polyvinyl chloride is preferable.

(Chlorinated polyethylene)
Chlorinated polyethylene means a chlorinated ethylene homopolymer and a chlorinated copolymer of ethylene and an α-olefin having 12 or less (preferably 3 to 9) carbon atoms.
In this ethylene-α-olefin copolymer, the content of the ethylene component is 70% by mass or more, preferably 80% by mass or more, and the content of the α-olefin component is 30% by mass or less, 20% by mass. % Or less is preferable.
The method for chlorination is not particularly limited, and examples thereof include a method commonly used as a method for producing chlorinated polyethylene. For example, a method of chlorinating ethylene homopolymer or ethylene / α-olefin copolymer powder by introducing chlorine gas in the vicinity of the softening temperature of the polymer in an aqueous suspension (so-called aqueous suspension method) ). In addition, after the polymer is dissolved in a solvent, a method of reacting with chlorine gas in the presence of a catalyst to chlorinate is also included.
As chlorinated polyethylene, non-crystalline chlorinated polyethylene, semi-crystalline chlorinated polyethylene, and the like can be used.
Although the content rate of a chlorine atom in chlorinated polyethylene is not specifically limited, 15-45 mass% is preferable.
The mass average molecular weight of the chlorinated polyethylene is preferably 10,000 to 10,000,000, and more preferably 50,000 to 1,000,000.
The chlorinated polyethylene is preferably a chlorinated ethylene homopolymer.

(Ethylene- (meth) acrylic acid ester copolymer)
As the ethylene- (meth) acrylic acid ester copolymer, an ethylene- (meth) acrylic acid alkyl ester copolymer is preferable, an ethylene- (meth) acrylic acid methyl copolymer, an ethylene- (meth) acrylic acid ethyl copolymer. Examples thereof include a polymer and an ethylene-butyl (meth) acrylate copolymer.
As content of the (meth) acrylic acid ester structural component in an ethylene- (meth) acrylic acid ester copolymer, 5-30 mass% is preferable.

(Ethylene-vinyl acetate copolymer)
As the ethylene-vinyl acetate copolymer, an ethylene-vinyl acetate copolymer usually referred to as EVA can be used. In the copolymer, the content of the vinyl acetate component is preferably 1 to 50% by mass, more preferably 5 to 30% by mass.

(polystyrene)
Examples of polystyrene include styrene homopolymer, styrene- (meth) acrylic acid ester copolymer (MS resin), styrene-maleic anhydride copolymer, and aromatic vinyl monomers other than styrene and styrene (for example, α-methyl). And a copolymer with styrene, paramethylstyrene, vinyl toluene, and vinyl xylene).
Among all the structural components of polystyrene, the content of the styrene structural component is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, still more preferably 70 to 100% by mass, and most preferably styrene homopolymer.

(Acrylonitrile-styrene copolymer)
The acrylonitrile-styrene copolymer is not particularly limited as long as it is a copolymer containing acrylonitrile and styrene as constituent components, and may have other constituent units.
Examples of the acrylonitrile-styrene copolymer include acrylonitrile-styrene copolymer (SAN), acrylonitrile-styrene-chlorinated polyethylene copolymer (ACS), and acrylonitrile-styrene-ethylene-vinyl acetate copolymer. Further, an α-methylstyrene-acrylonitrile copolymer in which the styrene component in these copolymers is replaced with an α-methylstyrene component is also included.
In the copolymer, the content of the acrylonitrile component is preferably 10 to 50% by mass, more preferably 20 to 40% by mass, and the content of the styrene component is preferably 50 to 90% by mass, and 60 to 80% by mass. More preferred.
Among these copolymers, an acrylonitrile-styrene copolymer (SAN) is preferable, and an acrylonitrile-styrene copolymer having an acrylonitrile constituent content of 3 to 30% by mass is more preferable.

The vinyl polymer (A) is preferably polyethylene, polypropylene, polymethylpentene, chlorinated polyethylene, polystyrene, or acrylonitrile-styrene copolymer, because the acoustic impedance is closer to the value of a living body and superior in chemical resistance. From the viewpoint that the acoustic wave attenuation can be further reduced, polystyrene or acrylonitrile-styrene copolymer is more preferable.
The vinyl polymer (A) is not particularly limited as long as it exhibits the effects of the present invention as a composite resin bonded to the polysiloxane (B). Preferred embodiments include the following embodiments.

As a mass average molecular weight of a vinyl type polymer (A), 50,000-1,000,000 are preferable and 100,000-500,000 are more preferable.
The vinyl polymer (A) preferably has a higher sound speed than the polysiloxane (B) from the viewpoint of obtaining acoustic impedance close to that of a living body. Specifically, the sound velocity at 25 ° C. is preferably 1,000 to 2,600 m / s, more preferably 1,000 to 2,500 m / s, and still more preferably 1,200 to 2,200 m / s. The speed of sound can be obtained by the method described in the example section.
Further, since the purpose of approximating the acoustic impedance to the body, the density of the vinyl polymer (A) is preferably from ^{0.7~1.6g / cm 3, 0.8~1.5g / cm} 3 is more preferable.
Further, for the purpose of imparting excellent molding processability to components of acoustic wave probes such as ultrasonic probes, the MFR (melt flow rate) of the vinyl polymer (A) is 0.1 to 300 g / 10 min. . Is preferably 0.3 to 100 g / 10 min. Is more preferred, 1-30 g / 10 min. Is more preferable. Here, MFR is a measured value under the conditions of temperature: 190 ° C. and load: 21.18 N according to JIS K7210. The same applies to the MFR described in the examples.
As the vinyl polymer (A), one type of component may be used, or two or more types of components may be used in combination.

(2) Polysiloxane (B)
The polysiloxane (B) is not particularly limited as long as it is a compound having a structural unit having a polysiloxane bond. The polysiloxane bond may be introduced into any of the main chain and / or the side chain in the structural unit, but is preferably introduced into the main chain.
The polysiloxane (B) used in the present invention is not particularly limited. For example, the trialkylsiloxy-terminated polydialkylsiloxane (b1), the polysiloxane (b2) having a vinyl group, and the polysiloxane having a halogen atom described below. And polyorganosiloxanes such as siloxane (b3) and polysiloxane (b4) having an aryl group.
In addition, when it can classify | categorize also in any polysiloxane of (b1)-(b4), it shall classify | categorize into each polysiloxane in order from what has a vinyl group, a halogen atom, and an aryl group as a functional group. .

Trialkylsiloxy-terminated polydialkylsiloxane (b1)
The trialkylsiloxy-terminated polydialkylsiloxane (b1) (hereinafter also simply referred to as “polysiloxane (b1)”) is not particularly limited, but for example, a polysiloxane represented by the following general formula (1) is preferable.

In the general formula (1), R ^a0 represents an alkyl group. x0 represents an integer of 1 or more.

1-10 are preferable, as for carbon number of the alkyl group in R ^<a0> , 1-4 are more preferable, 1 or 2 is more preferable, and 1 is especially preferable. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-hexyl, n-octyl, 2-ethylhexyl and n-decyl, and methyl is preferable.

  x0 is preferably an integer of 5 to 250,000, more preferably an integer of 50 to 25,000.

The mass average molecular weight of the polysiloxane (b1) is preferably 500 to 20,000,000, more preferably 1,000 to 10,000,000 from the viewpoint of mechanical strength, hardness, and ease of processing. 000 to 5,000,000 is more preferable, and 10,000 to 1,000,000 is particularly preferable.
All of the above polysiloxanes (b1) are trade names of DMS-T31, DMS-T35, DMS-T41, DMS-T43, DMS-T46, DMS-T51, DMS-T53, and DMS-T56 manufactured by Gelest. , DMS-T61, DMS-T72, and the like.

Polysiloxane having a vinyl group (b2)
The polysiloxane (b2) having a vinyl group (hereinafter also simply referred to as “polysiloxane (b2)” or “vinyl silicone”) has two or more vinyl groups in the molecular chain.
Examples of the polysiloxane (b2) include a polysiloxane (b2-1) having vinyl groups at both ends of the molecular chain (hereinafter, also simply referred to as “polysiloxane (b2-1)”), or in the molecular chain. A polysiloxane (b2-2) having at least two —O—Si (CH ₃ ) ₂ (CH═CH ₂ ) (hereinafter also simply referred to as “polysiloxane (b2-2)”). Of these, polysiloxane (b2-1) having vinyl groups at least at both ends of the molecular chain is preferable.
The polysiloxane (b2-1) is preferably linear, and in the polysiloxane (b2-2), —O—Si (CH ₃ ) ₂ (CH═CH ₂ ) is bonded to the Si atom constituting the main chain. Polysiloxane is preferred.

  The polysiloxane (b2) having a vinyl group is a polysiloxane having two or more Si—H groups in the molecular chain in the presence of a platinum catalyst (hereinafter referred to as “crosslink” with the vinyl polymer (A)). , Also referred to as “hydrosilicone”), a crosslinked structure is also formed by a hydrosilylation reaction (addition curing reaction).

The vinyl group content of the polysiloxane (b2) is not particularly limited. In addition, from the viewpoint of forming a sufficient network with the vinyl polymer (A), for example, the content of vinyl groups is preferably 0.01 to 5 mol%, more preferably 0.05 to 2 mol%. .
The polysiloxane (b2) preferably has a phenyl group, and the content of the phenyl group is not particularly limited. From the viewpoint of mechanical strength when used as a resin material for acoustic wave probes, for example, the phenyl group content is preferably 1 to 80 mol%, more preferably 2 to 40 mol%.

Here, the content of the vinyl group is the mol% of the vinyl group-containing siloxane unit when the total units constituting the polysiloxane (b2) are 100 mol%, and the Si—O unit constituting the main chain and When all the Si atoms of the terminal Si are substituted with at least one vinyl group, the amount is 100 mol%.
Similarly, the phenyl group content is the mol% of the phenyl group-containing siloxane unit when the total units constituting the polysiloxane (b2) are 100 mol%, and the Si—O unit and terminal constituting the main chain. When all Si atoms of Si are substituted with at least one phenyl group, the amount is 100 mol%.
In addition, a unit means the Si-O unit which comprises a principal chain, and terminal Si.

  The degree of polymerization and specific gravity are not particularly limited. The degree of polymerization is preferably 200 to 3000, more preferably 400 to 2000, and the specific gravity is 0.9 to 1 from the viewpoint of improving the mechanical strength, hardness, chemical stability, etc. of the obtained resin material for acoustic wave probes. .1 is preferred.

  The mass average molecular weight of the polysiloxane (b2) is preferably 10,000 to 200,000, more preferably 20,000 to 200,000, and more preferably 30,000 to 200,000 from the viewpoints of mechanical strength, hardness and ease of processing. 150,000 is more preferable, and 40,000 to 120,000 is particularly preferable.

Kinematic viscosity at 25 ° C. is preferably ^{1 × 10 -5 ~10m 2 / s} , more preferably ^{1 × 10 -4 ~1m 2 / s} , 1 × 10 -3 ~0.5m 2 / s is more preferable.
The kinematic viscosity can be determined according to JIS Z8803 by measuring at a temperature of 23 ° C. using an Ubbelohde viscometer (for example, trade name SU, manufactured by Shibata Chemical Co., Ltd.).

  The polysiloxane (b2-1) having vinyl groups at least at both ends of the molecular chain is preferably a polysiloxane represented by the following general formula (2).

In the general formula (2), R ^a1 represents a vinyl group, and R ^a2 and R ^a3 each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group. x1 and x2 each independently represents an integer of 1 or more. Here, each group of R ^a2 and R ^a3 may be further substituted with a substituent.

1-10 are preferable, as for carbon number of the alkyl group in R ^{< a2>} and R ^<a3> , 1-4 are more preferable, 1 or 2 is more preferable, and 1 is especially preferable. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-hexyl, n-octyl, 2-ethylhexyl and n-decyl.

3-10 are preferable, as for carbon number of the cycloalkyl group in R ^{< a2>} and R ^<a3 >, 5-10 are more preferable, and 5 or 6 is still more preferable. The cycloalkyl group is preferably a 3-membered ring, 5-membered ring or 6-membered ring, more preferably a 5-membered ring or 6-membered ring. Examples of the cycloalkyl group include cyclopropyl, cyclopentyl, and cyclohexyl.

2-10 are preferable, as for carbon number of the alkenyl group in R ^{< a2>} and R ^<a3 >, 2-4 are more preferable, and 2 is more preferable. Examples of the alkenyl group include vinyl, allyl, and butenyl.

6-12 are preferable, as for carbon number of the aryl group in R ^{< a2>} and R ^<a3 >, 6-10 are more preferable, and 6-8 are more preferable. Examples of the aryl group include phenyl, tolyl, and naphthyl.

These alkyl group, cycloalkyl group, alkenyl group and aryl group may have a substituent. Examples of such a substituent include a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a silyl group, and a cyano group.
Examples of the group having a substituent include a halogenated alkyl group.

R ^a2 and R ^a3 are preferably an alkyl group, an alkenyl group or an aryl group, more preferably an alkyl group having 1 to 4 carbon atoms, a vinyl group or a phenyl group, and further preferably a methyl group, a vinyl group or a phenyl group.
R ^a2 is particularly preferably a methyl group, and R ^a3 is particularly preferably a methyl group or a phenyl group. More preferably, both R ^a3 in repeating x2 are a methyl group or a phenyl group.

x1 is preferably an integer of 1 to 3000, and more preferably an integer of 5 to 1000.
x2 is preferably an integer of 1 to 3000, and more preferably an integer of 40 to 1000.

Polysiloxane (b2-1) having vinyl groups at both ends of the molecular chain is, for example, a trade name made by Gelest, DMS series (for example, DMS-V31, DMS-V31S15, DMS-V33, DMS-V35, DMS). -V35R, DMS-V41, DMS-V42, DMS-V46, DMS-V51, DMS-V52), trade names made by Gelest, PDV series (for example, PDV-0341, PDV-0346, PDV-0535, PDV- 0541, PDV-1631, PDV-1635, PDV-1641, PDV-2335, PMV-9925, PVV-3522, FMV-4031, EDV-2022).
In addition, since DMS-V31S15 is previously blended with fumed silica, kneading with a special apparatus is unnecessary.

Polysiloxane having a halogen atom (b3)
The polysiloxane (b3) having a halogen atom (hereinafter, also simply referred to as “polysiloxane (b3)”) is not particularly limited, but for example, a polysiloxane represented by the following general formula (3) is preferable.

In the general formula (3), R ^a4 represents an alkyl group. R ^a5 represents an alkyl group having a halogen atom. x3 represents an integer of 1 or more.

The alkyl group in R ^a4 is synonymous with the alkyl group in R ^a0 of the general formula (1), and the preferred range is also the same.
1-10 are preferable, as for carbon number of the alkyl group which has a halogen atom in R ^a5 , 1-4 are more preferable, and 1-3 are especially preferable. Examples of the alkyl group having a halogen atom include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl, 2,2,3,3-tetrafluoropropyl, 2,2,3,3,3-pentafluoropropyl are mentioned, and 3,3,3-trifluoropropyl is preferable. .
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

  x3 is preferably an integer of 5 to 250,000, more preferably an integer of 50 to 25,000.

  The mass average molecular weight of the polysiloxane (b3) is preferably 500 to 20,000,000, more preferably 1,000 to 10,000,000 from the viewpoint of mechanical strength, hardness, and ease of processing. 000 to 5,000,000 is more preferable, and 10,000 to 1,000,000 is particularly preferable.

  Examples of the polysiloxane (b3) include trade names such as FMS-121, FMS-123, FMS-131, and FMS-141 manufactured by Gelest.

Polysiloxane having aryl group (b4)
The polysiloxane (b4) having an aryl group (hereinafter, also simply referred to as “polysiloxane (b4)”) has a diaryl structure (—Si (aryl)) depending on the bonding position of the organic chain containing the aryl group to the Si atom. _2- ) and those having an alkylaryl structure (-Si (aryl) (alkyl)-).
As the polysiloxane (b4) having a diaryl structural unit or a dialkylaryl structural unit, for example, a polysiloxane represented by the following general formula (4) is preferable.

In the general formula (4), R ^a6 represents an alkyl group. R ^a7 represents an alkyl group or an aryl group. However, at least one of the plurality of R ^a7 represents an aryl group. X4 and X5 represent an integer of 1 or more.

The alkyl group in R ^a6 has the same meaning as the alkyl group in R ^a1 of the general formula (1), and the preferred range is also the same.
The alkyl group in R ^a7 has the same meaning as the alkyl group in R ^a1 of the general formula (1), and the preferred range is also the same.
The number of carbon atoms of the aryl group in R ^a7 preferably 6 to 12, more preferably 6 to 10, 6 to 8 is more preferred. Examples of the aryl group include phenyl, tolyl, and naphthyl, and phenyl is preferable.

x4 is preferably an integer of 1 to 200,000, more preferably an integer of 10 to 20,000.
x5 is preferably an integer of 1 to 200,000, more preferably an integer of 10 to 20,000.

Moreover, as polysiloxane (b4), the trisiloxane which has a diaryl structure or a dialkylaryl structure is also preferable. As the alkyl group and the aryl group, an alkyl group in R ^a1 of the general formula (1) and an aryl group in R ^a7 of the general formula (4) are preferably applied.
Examples of such trisiloxane include 1,1,5,5-tetraphenyl-1,3,3,5-tetramethyltrisiloxane, 1,1,3,5,5-pentaphenyl-1,3. , 5-trimethyltrisiloxane.

  The content of the aryl group is not particularly limited. From the viewpoint of mechanical strength when the resin material for acoustic wave probes is used, for example, the aryl group content is preferably 1 to 80 mol%, and more preferably 3 to 25 mol%.

  The mass average molecular weight of the polysiloxane (b4) is preferably 500 to 20,000,000, more preferably 1,000 to 10,000,000, from the viewpoint of mechanical strength, hardness, and ease of processing. 000 to 5,000,000 is more preferable, and 10,000 to 1,000,000 is particularly preferable.

In the present invention, the polysiloxane represented by the general formula (4) is preferable, and R ^a7 in the parenthesis to which X5 is attached is more preferably an alkyl group, and the parenthesis in the parenthesis to which X5 is attached. More preferably, each of R ^a7 is an alkyl group, and one of R ^a7 in parentheses to which X4 is attached is an aryl group and the other is an alkyl group.

  Examples of the polysiloxane (b4) include PDM-0421, PDM-0821, PDM-0122, PMM-1015, PMM-1025, PMM-1043, PMM-5021, PMM-6025, PMM-0011, and PMM manufactured by Gelest. -0021, PMM-0025, PMP-5025, PDM-7040, PDM-7050 and the like.

  As the polysiloxane (B), one type of component may be used, or two or more types of components may be used in combination.

The sound speed of polysiloxane (B) at 25 ° C. is usually 900 to 1,200 m / s. From the relationship with the vinyl polymer (A), 950 to 1,100 m / s is preferable. The speed of sound can be obtained by the method described in the example section.
Moreover, the density of polysiloxane (B) is 0.8-1.3 g / cm < ³ > normally. From the viewpoint of bringing the acoustic impedance closer to the human body, 0.9 to 1.2 g / cm ³ is preferable.

(3) Composite resin In the composite resin, the mass ratio of the polysiloxane (B) to the vinyl copolymer (A) is as follows: vinyl copolymer (A): polysiloxane (B) = 1: 99 to 99: 1 is preferred. By making the contained mass ratio within the above range, the compatibility between the vinyl copolymer (A) and the polysiloxane (B) is further improved, and the acoustic wave sensitivity of the resin sheet obtained from the resin material of the present invention is further increased. Can be increased. Moreover, from the point which makes acoustic impedance a value closer to a living body (sound speed and density adjustment point), vinyl copolymer (A): polysiloxane (B) = 20: 80 to 80:20 is more preferable. 30:70 to 70:30 is more preferable.
Here, the contained masses of the vinyl copolymer (A) and the polysiloxane (B) in the composite resin can be calculated from, for example, the charged amount (mass ratio) at the time of synthesis.
In the acoustic wave probe resin material, the content of the composite resin is not particularly limited, but is preferably 70 to 100% by mass, and more preferably 85 to 100% by mass.
A preferable content ratio by mass of the vinyl copolymer (A) and the polysiloxane (B) in the resin material for acoustic probe is that of the vinyl copolymer (A) and the polysiloxane (B) in the composite resin described above. It is the same as a preferable mass ratio. Here, in the case of “vinyl copolymer (A) in the resin material for acoustic wave probes”, in addition to the vinyl copolymer constituting the composite resin, the vinyl copolymer existing without being bonded to polysiloxane. The meaning includes coalescence. The term “polysiloxane (B) in the resin material for acoustic wave probes” means that in addition to the polysiloxane constituting the composite resin, the polysiloxane present without being bonded to the vinyl copolymer is included.

The composite resin may have a structural unit other than the vinyl copolymer (A) and the polysiloxane (B) (hereinafter referred to as other structural unit).
Other structural units can be introduced without particular limitation as long as the effects of the present invention are exhibited. For example, in addition to the vinyl copolymer (A) and the polysiloxane (B), they are bonded to both. And specifically, components derived from a (meth) acrylate monomer.
In the composite resin, the proportion of other structural units is preferably 0 to 30% by mass, and more preferably 0 to 20% by mass.

  The composite resin used for this invention may be used individually by 1 type, and may be used in combination of 2 or more type. In addition, the vinyl copolymer (A) and the polysiloxane (B) in the composite resin used in the present invention may be one kind or two or more kinds, respectively.

The resin material for an acoustic wave probe of the present invention preferably has a gel fraction of 40% by mass or more, more preferably 60% by mass or more, and further preferably 80% by mass or more. A practical upper limit is 100% by mass. It shows that the higher the gel fraction, the more the vinyl copolymer (A) and polysiloxane (B) are bonded and the higher the molecular weight, the lower the solubility in the solvent. When the gel fraction is within the above range, the acoustic wave sensitivity of the constituent members of the acoustic wave probe obtained from the resin material of the present invention can be further increased.
Here, the gel fraction can be calculated, for example, by the following method.
A 100 mg sample cut out from the resin material is immersed in 10 g of tetrahydrofuran at room temperature for 24 hours and then taken out and dried at 100 ° C. for 2 hours. The gel fraction is calculated by the following formula from the sample mass m ₀ before immersion and the sample mass m ₂₄ after immersion and drying.
Gel fraction (mass%) = m ₂₄ / m ₀ × 100
In addition, for the bond formation between the vinyl polymer (A) and the polysiloxane (B), the vinyl polymer (A) and the polysiloxane (B) are dissolved, and the vinyl polymer (A) and the polysiloxane ( It can also be confirmed using a solvent (for example, hexafluoroisopropanol) in which the composite resin to which B) is bound does not dissolve.

The acoustic impedance of the constituent member of the acoustic wave probe obtained from the resin material of the present invention is preferably close to the value of a living body, and more preferably 1.2 Mrayls, that is, 1.2 × 10 ⁶ kg / m ² / s or more. Preferably, it is 1.3 × 10 ⁶ kg / m ² / s or more. Therefore, the density of the resin material for the acoustic wave probe of the present invention is preferably 0.90 g / cm ³ or more 2.00 g / cm ³ or less, 0.95 g / cm ³ or more 1.80 g / cm ^3, more preferably less , more preferably 0.95 g / cm ³ or more 1.60 g / cm ³ or less. Further, the sound velocity at 25 ° C. of the resin material for acoustic wave probes of the present invention is preferably 1,800 m / s or less, and more preferably 1,600 m / s or less. Here, the density value is a value obtained by rounding off the third decimal place. The density of the resin material for acoustic wave probes of the present invention can be measured, for example, by the method described in Examples described later, or calculated from the density of each resin. The speed of sound can be obtained by the method described in the section of the example.

(Synthesis of composite resin)
The composite resin used in the present invention is preferably produced at the same time as the production of the acoustic probe resin material. Details will be described later in the method for manufacturing the acoustic wave probe resin material and the acoustic wave probe resin sheet.

(3) Other additives The resin material for an acoustic wave probe of the present invention appropriately contains a filler, a catalyst, a solvent, a dispersant, a pigment, a dye, an antistatic agent, a flame retardant, a thermal conductivity improver, a curing retarder, and the like. Can be blended.

− Filler −
The resin material for an acoustic wave probe of the present invention can produce a resin sheet having excellent characteristics without containing an inorganic filler, but may contain a filler.
The filler can be used without particular limitation as long as it is a filler used in a resin material for an acoustic wave probe, and specifically includes inorganic compound particles.
Examples of inorganic compounds in the inorganic compound particles include silicon oxide (silica), silicon carbide, boron nitride, alumina, barium sulfate, cerium oxide, calcium carbonate, aluminum nitride, calcium oxide, vanadium oxide, silicon nitride, barium carbonate, titanium carbide, Examples include titanium nitride, copper oxide, zirconium carbide, tungsten carbide, magnesium oxide, titanium oxide, iron oxide, zinc oxide, zirconium oxide, barium oxide, tin oxide and ytterbium oxide, silica, silicon carbide, boron nitride, alumina, sulfuric acid Any one selected from the group consisting of barium and cerium oxide is preferable, any one selected from the group consisting of silica, alumina, barium sulfate and cerium oxide is more preferable, and silica is more preferable.

  When the acoustic wave probe resin material contains inorganic compound particles, the acoustic impedance and mechanical strength (tear strength, hardness, etc.) of the acoustic wave probe resin can be improved.

  The average primary particle diameter of the inorganic compound particles is preferably more than 16 nm and less than 100 nm, more preferably 5 nm to 90 nm, more preferably 10 nm from the viewpoint of suppressing an increase in acoustic wave attenuation of the resin for acoustic wave probes and improving the tear strength. -80 nm is more preferable, and 15 nm to 70 nm is particularly preferable.

Here, the average primary particle diameter means a volume average particle diameter. The volume average particle diameter can be measured, for example, by using a laser diffraction / scattering particle size distribution measuring apparatus (for example, trade name “LA910” manufactured by Horiba, Ltd.). In the present specification, those whose average primary particle diameter is not described in the catalog or those newly produced are average primary particle diameters determined by the above measurement method.
Here, the average primary particle diameter of the inorganic compound particles means the average primary particle diameter in a surface-treated state.

  Inorganic compound particles may be used alone or in combination of two or more.

Inorganic compound particles, from the viewpoint of improving the hardness and / or mechanical strength of the resin for an acoustic wave probe obtained, the specific surface area is preferably 1~400m ² / g, more preferably 5 to 200 m ² / g, 10 to 100 m ² / g is particularly preferred.

The inorganic compound particles are preferably treated (modified) on the surface of the particles, and more preferably surface-treated with a silane compound.
By subjecting the inorganic compound particles to a surface treatment with a silane compound, the interaction with the composite resin used in the present invention containing polysiloxane (B) is strengthened, and the affinity is increased. It is considered that small inorganic compound particles can be finely dispersed. For this reason, it is considered that the inorganic compound fine particles exhibit a function as a stopper when mechanical adaptability is applied, and the hardness and mechanical strength of the acoustic wave probe resin are improved.
The surface treatment method may be a normal method. Examples of the surface treatment method with a silane compound include a method of surface treatment with a silane coupling agent and a method of coating with a silicone compound.

(I) Silane coupling agent The silane coupling agent is preferably a silane coupling agent having a hydrolyzable group from the viewpoint of improving the hardness and / or mechanical strength of the acoustic wave probe resin. The hydrolyzable group in the silane coupling agent is hydrolyzed with water to become a hydroxyl group, and this hydroxyl group undergoes a dehydration condensation reaction with a hydroxyl group on the surface of the inorganic compound particle, whereby the surface modification of the inorganic compound particle is performed and obtained. The hardness and / or mechanical strength of the acoustic wave probe resin is improved. Examples of the hydrolyzable group include an alkoxy group, an acyloxy group, and a halogen atom.
In addition, if the surface of the inorganic compound particles is hydrophobically modified, the affinity between the inorganic compound particles and vinyl silicone and hydrosilicone is improved, and the hardness and mechanical strength of the resulting acoustic wave probe resin are improved. Therefore, it is preferable.

  Examples of the silane coupling agent having a hydrophobic group as a functional group include methyltrimethoxysilane (MTMS), dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n -Alkoxysilanes such as propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane and decyltrimethoxysilane; such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane and phenyltrichlorosilane Chlorosilane; and hexamethyldisilazane (HMDS).

  Examples of the silane coupling agent having a vinyl group as a functional group include methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, and vinyltriethoxy. Silanes, alkoxysilanes such as vinyltrimethoxysilane and vinylmethyldimethoxysilane; chlorosilanes such as vinyltrichlorosilane and vinylmethyldichlorosilane; and divinyltetramethyldisilazane.

As the silane coupling agent, a trialkylsilylating agent is preferable, and a trimethylsilylating agent is more preferable.
As a silane compound, the silane coupling agent by which the functional group in the said silane coupling agent and a silane coupling agent was substituted by the alkyl group is mentioned, for example.
Examples of the trimethylsilylating agent include trimethylchlorosilane and hexamethyldisilazane (HMDS) described in the above silane coupling agent and methyltrimethoxysilane (silane coupling agent in which a functional group is substituted with an alkyl group). MTMS) and trimethylmethoxysilane.

Examples of commercially available silane coupling agents include hexamethyldisilazane (HMDS) (trade name: HEXAMETHYLDISILAZANE (SIH6110.1) and manufactured by Gelest).
Hydroxyl groups present on the surface of inorganic compound particles are covered with trimethylsilyl groups by reaction with hexamethyldisilazane (HMDS), methyltrimethoxysilane (MTMS), trimethylmethoxysilane, etc., and the surface of inorganic compound particles is modified to be hydrophobic. Is done.
In the present invention, the silane coupling agent may be used alone or in combination of two or more.

(Ii) Silicone Compound The silicone compound that coats the inorganic compound particles may be a polymer composed of siloxane bonds.
Examples of the silicone compound include a silicone compound in which all or part of the side chain and / or terminal of polysiloxane is a methyl group, a silicone compound in which part of the side chain is a hydrogen atom, side chain and / or terminal Examples thereof include a modified silicone compound in which an organic group such as an amino group and / or an epoxy group is introduced into all or a part of the above, and a silicone resin having a branched structure. The silicone compound may have a linear or cyclic structure.

  Examples of silicone compounds in which all or part of the side chain and / or terminal of polysiloxane are methyl groups include polymethylhydrosiloxane (hydrogen terminal), polymethylhydrosiloxane (trimethylsiloxy terminal), and polymethylphenyl. Monomethyl polysiloxanes such as siloxane (hydrogen terminated) and polymethylphenylsiloxane (trimethylsiloxy terminated), for example dimethylpolysiloxane (hydrogen terminated), dimethylpolysiloxane (trimethylsiloxy terminated) and dimethylpolysiloxane such as cyclic dimethylpolysiloxane Examples include siloxane.

  Examples of silicone compounds in which a part of the side chain is a hydrogen atom include methylhydrosiloxane-dimethylsiloxane copolymer (trimethylsiloxy-terminated), methylhydrosiloxane-dimethylsiloxane copolymer (hydrogen-terminated), and polymethylhydrosiloxane (hydrogen-terminated). Polymethylhydrosiloxane (trimethylsiloxy-terminated), polyethylhydrosiloxane (triethylsiloxy-terminated), polyphenyl- (dimethylhydrosiloxy) siloxane (hydrogen-terminated), methylhydrosiloxane-phenylmethylsiloxane copolymer (hydrogen-terminated), methylhydro Mention may be made of siloxane-octylmethylsiloxane copolymers and methylhydrosiloxane-octylmethylsiloxane-dimethylsiloxane terpolymers.

  Examples of the modified silicone introduced with an organic group include, for example, amino group, epoxy group, methoxy group, (meth) acryloyl group, phenol group, carboxylic anhydride group, hydroxy group, mercapto group, carboxy group and / or hydrogen. Reactive silicones incorporating atomic organic groups and non-reactives modified with, for example, polyethers, aralkyls, fluoroalkyls, long chain alkyls, long chain aralkyls, higher fatty acid esters, higher fatty acid amides and / or polyether methoxys Examples include silicone.

The inorganic compound particles coated with the silicone compound can be obtained by a conventional method. For example, it can be obtained by mixing and stirring inorganic compound particles in dimethylpolysiloxane for a certain time and filtering.
In addition, when reactive modified silicone is used as the silicone compound, the organic group reacts with the hydroxyl group on the surface of the inorganic compound particle, whereby the surface modification of the inorganic compound particle is performed, and the obtained acoustic probe resin Hardness and / or mechanical strength are improved.

  Examples of commercially available silicone compounds include methyl hydrogen silicone oil (MHS) (trade name: KF-99, manufactured by Shin-Etsu Chemical Co., Ltd.), which is polymethylhydrosiloxane (trimethylsiloxy terminal).

The degree of surface modification of the inorganic compound particles, that is, the degree of hydrophobicity of the inorganic compound particles can be examined by the following degree of methanol hydrophobicity.
The inorganic compound particles preferably have a methanol hydrophobization degree calculated by the following methanol titration test of 40 to 80% by mass, more preferably 50 to 80% by mass, and 60 to 80% by mass. Is more preferable. Here, the greater the degree of methanol hydrophobization, the higher the hydrophobicity, and the smaller the degree, the higher the hydrophilicity.
50 ml of ion-exchanged water and 0.2 g of inorganic compound particles as a sample are put in a beaker and the temperature is 25 ° C., and methanol is dropped from a burette to a place where the sample is stirred with a magnetic stirrer. Xg) is measured. The degree of hydrophobization of methanol is calculated from the following formula.

  Methanol hydrophobicity (mass%) = {X / (50 + X)} × 100

  When the degree of methanol hydrophobization is within the above preferred range, an increase in viscosity of the acoustic probe resin material can be suppressed, and a decrease in acoustic wave sensitivity of the acoustic probe resin sheet can be suppressed.

The sphericity of the Wardel in the primary particles of the inorganic compound particles is preferably 0.7 to 1, more preferably 0.8 to 1, and still more preferably 0.9 to 1.
Here, “Wadell's sphericity” (see Chemical Engineering Handbook, published by Maruzen Co., Ltd.) is the sphericity of a particle ((diameter of circle equal to the projected area of the particle) / (minimum circumscribing the projected image of the particle) It is an index measured by (diameter of circle), and the closer this index is to 1.0, the closer the particle is to a true sphere.
For example, an SEM (Scanning Electron Microscope) photograph can be used for measurement of Wardel's sphericity (hereinafter also simply referred to as sphericity). Specifically, for example, about 100 primary particles are observed from the SEM photograph, and their sphericity is calculated. The average value obtained by dividing the total calculated sphericity by the number of observed primary particles is defined as sphericity.

When the sphericity of the Wardel is within the above preferable range, it is considered that the acoustic wave sensitivity is improved because the area of the acoustic wave that hits the inorganic compound particles is reduced when the acoustic wave is irradiated onto the resin sheet for acoustic wave probes. In particular, in the range of a specific average primary particle diameter possessed by the inorganic compound particles, the acoustic wave sensitivity is more effectively improved, so that the shape of the inorganic compound particles is preferably spherical, and more preferably spherical. preferable.
In the present specification, the “true sphere” includes a slightly distorted sphere having a Wadel sphericity in the range of 0.9 to 1.

Among inorganic compound particles, silica particles are produced by combustion method silica obtained by burning a silane compound (that is, fumed silica), deflagration method silica obtained by explosively burning metal silicon powder, Wet silica obtained by neutralization of sodium silicate and mineral acid (obtained by hydrolysis of precipitated silica, synthesized by alkali, gel silica by acidic) and hydrocarbyloxysilane Sol-gel method silica (so-called Stöber method).
Explosive methods and sol-gel methods are preferable as the method for producing true spherical silica particles, which are preferable.

The sol-gel method is a hydrophilic spherical silica consisting essentially of SiO ₂ units by hydrolyzing and condensing hydrocarbyloxysilane (preferably tetrahydrocarbyloxysilane) or a partial hydrolysis condensation product thereof or a combination thereof. This is a method for obtaining particles.
In addition, the hydrophobization treatment on the surface of the silica particle is performed on the surface of the hydrophilic spherical silica particle by R ³ ₃ SiO _1/2 unit (R ³ is the same or different, and is a substituted or unsubstituted 1 to 20 carbon atom number. (Hydrovalent hydrocarbon group) can be introduced.
Specifically, for example, it can be carried out by the methods described in JP2007-99582A and JP2014-114175A.

− Catalyst −
Examples of the catalyst include platinum or a platinum-containing compound (hereinafter also simply referred to as a platinum compound). Any platinum or platinum compound can be used.
Specifically, platinum black or platinum supported on an inorganic compound or carbon black, chloroplatinic acid or an alcohol solution of chloroplatinic acid, complex salt of chloroplatinic acid and olefin, complex salt of chloroplatinic acid and vinylsiloxane Etc. A catalyst may be used individually by 1 type and may be used in combination of 2 or more type.

The catalyst is necessary in the hydrosilylation reaction in which the Si—H group of the hydrosilicone is added to the vinyl group of the vinylsilicone. By proceeding with the hydrosilylation reaction (addition curing reaction), a silicone resin in which vinyl silicone is crosslinked with hydrosilicone is obtained.
Here, the catalyst may be contained in the resin material for acoustic wave probes of the present invention, or the acoustic wave probe is formed by using the resin material for acoustic wave probes without being contained in the resin material for acoustic wave probes. You may make it contact with the resin material for acoustic wave probes, when shape | molding a member. The latter is preferred.

  Commercially available platinum catalysts include, for example, platinum compounds (trade names: PLATINUM CYCLOVINYLMETHYLSILOXIPANE COMPLEX IN CYCLIC METHYLTYLINTYLINTLETLITELXYLITELXYLITELXYLITELXYLITELMETLITELMETLITELXYLETLITELETLETLETLETLETLETLETLETLETTLETH Pt concentration of 3% by mass, both manufactured by Gelest).

  When the catalyst is contained in the resin material for acoustic wave probes of the present invention, the content of the catalyst is not particularly limited, but from the viewpoint of reactivity, with respect to a total of 100 parts by mass of hydrosilicone and vinylsilicone, 0.00001 to 0.05 parts by mass is preferable, 0.00001 to 0.01 parts by mass is more preferable, 0.00002 to 0.01 parts by mass is further preferable, and 0.00005 to 0.005 parts by mass is particularly preferable. .

  Further, the curing temperature can be adjusted by selecting an appropriate platinum catalyst. For example, platinum-vinyldisiloxane is used for room temperature curing (RTV) at 50 ° C. or lower, and platinum-cyclic vinylsiloxane is used for high temperature curing (HTV) at 130 ° C. or higher.

− Cure retarder −
In the present invention, a curing retarder for the hydrosilylation reaction (addition curing reaction) can be appropriately used. The curing retarder is used for the purpose of delaying the addition curing reaction, and examples thereof include a low molecular weight vinylmethylsiloxane homopolymer (trade name: VMS-005, manufactured by Gelest).
The curing rate, that is, the working time can be adjusted by the content of the curing retarder.

<< Resin for acoustic wave probe >>
The acoustic wave probe resin of the present invention comprises a vinyl polymer (A), a polysiloxane (B), an organic peroxide (C1), and / or a radical photopolymerization initiator (C2). That is, in the present invention, the term “resin” means including a form of a mixture containing two or more kinds of polymers. This mixture may be in the form of a composition in which each component is uniformly mixed.
For the vinyl polymer (A) and the polysiloxane (B), the description of the vinyl polymer (A) and the polysiloxane (B) in the acoustic wave probe resin material is preferably applied. Regarding the content ratio of the vinyl polymer (A) and the polysiloxane (B) and the content in the acoustic probe resin, the content ratio in the composite resin and the acoustic probe resin material Content descriptions are preferably applied.
In addition, the resin for acoustic wave probes of the present invention includes the vinyl polymer (A), the polysiloxane (B), and the organic peroxide (C1) and / or the photo radical polymerization initiator (C2). You may contain the other additive described with the resin material for acoustic wave probes of the said invention.

Organic peroxide (C1)
The organic peroxide (C1) in the present invention is a generally used organic peroxide such as hydroperoxide, dialkyl peroxide, peroxyester, diacyl peroxide and peroxyketal having an —O—O— bond in the molecule. An oxide is mentioned. The organic peroxide (C1) used in the present invention has a 10-hour half-life temperature of 70 ° C. or higher.

Specific examples include the following organic peroxides.
Hydroperoxide: p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, etc.

Dialkyl peroxide: bis (2-t-butylperoxyisopropyl) benzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, Di-t-hexyl peroxide, di-t-butyl peroxide, 2,5-bis (t-butylperoxy) -2,5-dimethyl-3-hexyne, etc.

Peroxyester: t-butylperoxybenzoate, t-butylperoxymaleate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxy Isopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-bis (benzoylperoxy) -2,5-dimethylhexane, t-butylperoxyacetate, etc.

Diacyl peroxide: bis (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide, dibenzoyl peroxide, bis (4-methylbenzoyl) peroxide, etc.

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

Among these organic peroxides, since the half-life decomposition temperature matches the processing temperature, those having a 10-hour half-life decomposition temperature of 100 ° C. to 170 ° C. are preferable, those of 100 ° C. to 120 ° C. are more preferable, Specifically, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-hexyl peroxide, bis (2-t -Butylperoxyisopropyl) benzene, t-butylperoxybenzoate, 2,5-bis (benzoylperoxy) -2,5-dimethylhexane, t-butylperoxyacetate, 2,2-bis (t-butyl) Peroxy) butane or n-butyl 4,4-bis (t-butylperoxy) valerate is preferred.
In addition, an organic peroxide (C1) may use 1 type of single component, and may use 2 or more types of components together.

The content of the organic peroxide (C1) is preferably 0.1 to 15 parts by mass, and preferably 0.2 to 10 parts by mass with respect to 100 parts by mass in total of the vinyl polymer (A) and the polysiloxane (B). Part is more preferred.
When the addition amount is in the above range, the cross-linking reaction between the vinyl polymer (A) and the polysiloxane (B) sufficiently proceeds and the compatibility is improved, so that the acoustic wave containing the composite resin obtained The acoustic wave attenuation is suppressed in the probe resin material. In addition, deterioration of physical properties such as a decrease in hardness peculiar to a silicone resin, insufficient rubber strength, and an increase in compression set are suppressed. Furthermore, it is economically preferable, and by suppressing the generation of decomposition products of the curing agent, deterioration of physical properties such as an increase in compression set and discoloration of the obtained resin material for acoustic wave probes can be suppressed.

Photoradical polymerization initiator (C2)
The radical photopolymerization initiator is not particularly limited as long as it is a compound that is activated by irradiation with electromagnetic waves in the ultraviolet to visible light range (preferably ultraviolet rays) and generates radical species. Agents (photoinitiators such as benzoin, benzyl ketal, and α-hydroxyacetophenone) can be used. Among these, a photoradical polymerization initiator that does not contain a nitrogen atom, a phosphorus atom, a sulfur atom or the like in the molecule is preferable, and a photoradical polymerization initiator that does not become a catalyst poison of platinum or a platinum compound used in the hydrosilylation reaction is more preferable. .
Specific examples of the photo radical polymerization initiator include 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by Ciba Specialty Chemicals, trade name: Darocur 1173, etc.), 1-hydroxy- Cyclohexyl-phenyl ketone (manufactured by Ciba Specialty Chemicals, trade name: Irgacure 184, etc.), 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1- Examples include ON (manufactured by Ciba Specialty Chemicals, trade name: Irgacure 2959, etc.), benzophenone, diethoxyacetophenone, and the like.
In addition, 1 type of component may be used for radical photopolymerization initiator (C2), and 2 or more types of components may be used together.

  The compounding amount of the radical photopolymerization initiator is preferably 0.01 to 10 parts by mass, and 0.03 to 5 parts by mass with respect to 100 parts by mass in total of the vinyl polymer (A) and the polysiloxane (B). More preferably, 0.05-3 mass parts is still more preferable, and 0.1-2 mass parts is especially preferable. When the addition amount is within the above range, sufficient curability can be obtained at the time of irradiation with light (preferably ultraviolet rays), and deep curability is also excellent.

The acoustic wave probe resin of the present invention is suitably used for producing the acoustic wave probe resin material of the present invention. The resin for an acoustic wave probe of the present invention is an organic peroxide (C1) and a photoradical polymerization initiator (C2) from the viewpoint of obtaining a component of an acoustic wave probe that is superior in reducing the attenuation of acoustic waves and chemical resistance. Of these, the organic peroxide (C1) is preferably contained.
The resin for acoustic wave probe of the present invention contains the organic peroxide (C1) and / or photoradical contained in order to prevent decomposition of the organic peroxide (C1) and / or photoradical polymerization initiator (C2). According to the polymerization initiator (C2), before use, it is preferably stored under conditions of 50 ° C. or lower, preferably 35 ° C. or lower, and / or under light shielding conditions. Further, it is particularly preferable to store in a refrigerator under light-shielding conditions when necessary so that the organic peroxide (C1) and / or the radical photopolymerization initiator (C2) are not decomposed.

<Resin material for acoustic wave probe and method for producing resin sheet for acoustic wave probe>
The resin material for an acoustic wave probe of the present invention comprises the resin for an acoustic wave probe of the present invention (the above vinyl copolymer (A), polysiloxane (B), organic peroxide (C1) and / or radical photopolymerization. And a mixture containing the initiator (C2). Here, the organic peroxide (C1) and the radical photopolymerization initiator (C2) are reaction initiators.
Reaction using organic peroxide (C1) as a reaction initiator is generation of free radicals due to cleavage of —O—O— bond in organic peroxide (C1) (activation of organic peroxide (C1)). Is used. The reaction using the photo radical polymerization initiator (C2) as a reaction initiator activates the photo radical polymerization initiator by irradiating with light, and the free radical generated from the activated photo radical polymerization initiator (C2). Use radicals. Utilizing these free radicals to extract hydrogen radicals (H.) in vinyl polymers (A) and / or polysiloxanes (B), and in some cases, addition reactions to ethylenically unsaturated double bonds, etc. Thus, a C—C bond is formed between the molecules, and a resin (composite resin) in which the vinyl polymer (A) and the polysiloxane (B) are bonded to each other is formed. This composite resin preferably has a three-dimensional crosslinked structure from the viewpoint of chemical resistance.
The activation of the organic peroxide (C1) is preferably performed by heating and / or light irradiation, and more preferably by heating.
The method for producing a resin material for an acoustic wave probe according to the present invention comprises a heat-melted vinyl polymer (A) and a heat-melted polysiloxane (B), an organic peroxide (C1) and / or a photoradical. It is preferable to include a step of reacting using a polymerization initiator (C2), and heat-melting vinyl polymer (A) and heat-melted polysiloxane (B) are combined with organic peroxide (C1). It is more preferable to include the process made to react. By including the above steps, the compatibility between the vinyl copolymer (A) and the polysiloxane (B) can be further improved, and the attenuation of the acoustic wave and the chemical resistance can be further improved.
Hereinafter, the resin material for acoustic wave probes and the method for producing the resin sheet for acoustic wave probes of the present invention will be described in detail.

(1) Mixing of each component In the manufacturing method of this invention, said vinyl-type copolymer (A), polysiloxane (B), organic peroxide (C1), and / or radical photopolymerization initiator (C2). And mix.
The mixing method is not particularly limited, but can be obtained by kneading using a lab plast mill, a kneader, a pressure kneader, a Banbury mixer (continuous kneader) or a two-roll kneading apparatus. Moreover, when it contains the said other component, it can obtain by kneading simultaneously. The mixing order of each component is not particularly limited.
The mixing conditions are not particularly limited as long as the subsequent forming into a sheet or the like is possible, and examples include a mode of kneading at 100 to 300 ° C. for 0.5 to 10 minutes.

A preferred embodiment of the present invention includes heating and kneading at a temperature at which the vinyl polymer (A) and the polysiloxane (B) are melted (hereinafter simply referred to as “melting temperature”). According to this embodiment, it is possible to obtain an acoustic wave probe resin in which the vinyl polymer (A) and the polysiloxane (B) are thermally melted.
Here, “heat-melted” means the state of the resin formed by temporarily turning the vinyl polymer (A) and the polysiloxane (B) into a fluid state by heating during kneading. That is, in the present invention, the heat-melted vinyl polymer (A) and the heat-melted polysiloxane (B) are heat-melted by heating above the melting temperature (also referred to as “heat-melting history”). The vinyl polymer (A) and polysiloxane (B) having
The “melting temperature” means a temperature that is 10 ° C. or more higher than the melting points of the vinyl polymer (A) and the polysiloxane (B), and a temperature that is 20 ° C. or more is preferable.
The heating and kneading conditions above the melting temperature are appropriately adjusted depending on the types of the vinyl polymer (A) and the polysiloxane (B), and are, for example, 0 at 100 to 300 ° C. (preferably 150 to 300 ° C.). The mode which knead | mixes for 5 to 10 minutes is mentioned.
In addition, the kneading at a temperature lower than the above melting temperature does not yield the heat-melted vinyl polymer (A) and polysiloxane (B) defined in the present invention.

(2) Formation into a sheet shape The resin mixed for acoustic probe of the present invention mixed as described above can be formed into a sheet shape (to obtain a resin sheet for acoustic wave probe) by, for example, hot pressing. There is no restriction | limiting in particular as the method of a hot press, It can carry out by a conventional method. For example, the aspect which heat-presses by the pressure of 5-30 MPa for 1 to 10 minutes at 80-300 degreeC using apparatuses, such as MINI TEST PRESS MP-WNL (the Toyo Seiki company make, brand name), is mentioned.

(3) Secondary Crosslinking The resin sheet for acoustic wave probes obtained above is preferably subjected to secondary crosslinking. By the secondary crosslinking, the bonding (crosslinking) between the vinyl copolymer (A) and the polysiloxane (B) in the acoustic wave probe resin sheet proceeds to the final stage, and the organic peroxide (C1) and It is possible to heat and remove the decomposition product of the radical photopolymerization initiator (C2) and stabilize the characteristics of the acoustic wave probe resin sheet.
In addition, the residue of an organic peroxide (C1) and / or radical photopolymerization initiator (C2) may remain in the resin sheet for acoustic wave probes.
The secondary cross-linking may be performed by any method of heating and light irradiation, but heating is preferable from the viewpoint of reduction of the acoustic wave attenuation and chemical resistance.
Heating and light irradiation can be appropriately adjusted depending on the type of organic peroxide (C1). Specifically, the heating is preferably performed at 200 to 300 ° C. for 1 to 10 hours, and the light irradiation is preferably ultraviolet (UV) irradiation. Specifically, the wavelength is 200 to 500 nm, and the UV intensity is 100. to 1,000 / cm ^2, manner of irradiation are mentioned 1 second to 5 minute light integrated light quantity 100~10,000mJ / cm ^2.
In the case of the photo radical polymerization initiator (C2), secondary crosslinking is performed by light irradiation. The conditions of light irradiation can be appropriately adjusted depending on the type of the photo radical polymerization initiator (C2). As a specific aspect of light irradiation, the light irradiation aspect of the organic peroxide (C1) can be exemplified.

  Note that the composite resin in which the vinyl copolymer (A) and the polysiloxane (B) are bonded may be formed at the stage of producing the acoustic wave probe resin sheet (resin material). In any of the steps of kneading and sheet formation in the production of the resin sheet (material) for the wave probe, the organic peroxide (C1) and / or the radical photopolymerization initiator (C2) is cleaved, and the vinyl copolymer Some or all of the bonds between (A) and polysiloxane (B) may be formed.

<Acoustic wave characteristics of resin sheet for acoustic wave probe>
The acoustic wave probe resin sheet is obtained by molding the acoustic wave probe resin of the present invention by hot pressing or the like.
Below, it describes in detail about the acoustic wave characteristic of the resin sheet for acoustic wave probes.
Here, the acoustic wave characteristic describes the ultrasonic characteristic. However, the acoustic wave characteristic is not limited to the ultrasonic characteristic, but relates to the acoustic wave characteristic of an appropriate frequency selected according to the object to be examined and the measurement conditions.

[Acoustic impedance]
The acoustic impedance is preferably close to the acoustic impedance of the living body, more preferably 1.20 × 10 ^{6 to} 1.80 × 10 ⁶ kg / m ² / sec, and 1.30 × 10 ^{6 to} 1.70 × 10 ^6. kg / m ² / sec is more preferable, 1.35 × 10 ^{6 to} 1.70 × 10 ⁶ kg / m ² / sec is particularly preferable, and 1.35 × 10 ^{6 to} 1.65 × 10 ⁶ kg / m ^2. / Sec is most preferable.
The acoustic impedance can be obtained by the method described in the example section.

[Acoustic wave (ultrasonic wave) attenuation, sensitivity]
It can be determined by the method described in the Examples section.
In the evaluation system of the present invention, the acoustic wave (ultrasonic wave) sensitivity is preferably −74 dB or more, more preferably −72 dB or more, further preferably −70 dB or more, and particularly preferably −68 dB or more.

The resin material for acoustic wave probes of the present invention is useful for medical members, and can be preferably used for, for example, acoustic wave probes and acoustic wave measuring apparatuses. The acoustic wave measuring apparatus of the present invention is not limited to an ultrasonic diagnostic apparatus or a photoacoustic wave measuring apparatus, but refers to an apparatus that receives an acoustic wave reflected or generated by an object and displays it as an image or signal intensity.
In particular, the resin material for an acoustic wave probe according to the present invention is provided between the acoustic lens of the ultrasonic diagnostic apparatus or the piezoelectric element and the acoustic lens, and has a role of matching the acoustic impedance between the piezoelectric element and the acoustic lens. Acoustic matching layer material, acoustic lens material in a photoacoustic wave measuring device or ultrasonic endoscope, and acoustic in an ultrasonic probe comprising a capacitive micromachined ultrasonic transducer (cMUT) as an ultrasonic transducer array It can be suitably used for a lens material or the like.
Specifically, the resin material for an acoustic wave probe of the present invention includes, for example, an ultrasonic diagnostic apparatus described in JP-A-2005-253751, JP-A-2003-169802, and JP-A-2013-202050. Preferred for acoustic wave measuring devices such as photoacoustic wave measuring devices described in Japanese Patent Laid-Open No. 2013-188465, JP 2013-180330, JP 2013-158435, 2013-154139, etc. Applied.

<< Acoustic wave probe (probe) >>
The configuration of the acoustic wave probe of the present invention will be described in more detail below based on the configuration of the ultrasonic probe in the ultrasonic diagnostic apparatus shown in FIG. In addition, an ultrasonic probe is a probe which uses an ultrasonic wave especially as an acoustic wave in an acoustic wave probe. Therefore, the basic structure of the ultrasonic probe can be applied to the acoustic wave probe as it is.

− Ultrasonic probe −
The ultrasonic probe 10 is a main component of the ultrasonic diagnostic apparatus, and has a function of generating ultrasonic waves and transmitting / receiving ultrasonic beams. As shown in FIG. 1, the configuration of the ultrasonic probe 10 is provided in the order of the acoustic lens 1, the acoustic matching layer 2, the piezoelectric element layer 3, and the backing material 4 from the tip (surface contacting the living body to be examined). ing. In recent years, for the purpose of receiving high-order harmonics, a transmitting ultrasonic transducer (piezoelectric element) and a receiving ultrasonic transducer (piezoelectric element) are made of different materials to form a laminated structure. Has also been proposed.

<Piezoelectric element layer>
The piezoelectric element layer 3 is a part that generates ultrasonic waves, and electrodes are attached to both sides of the piezoelectric element. When a voltage is applied, the piezoelectric element repeatedly vibrates and expands and expands to generate ultrasonic waves. To do.

As a material constituting the piezoelectric element, a crystal, a single crystal such as LiNbO ₃ , LiTaO ₃ and KNbO _3, a thin film such as ZnO and AlN, and a sintered body such as a Pb (Zr, Ti) O ₃ system were subjected to polarization treatment, So-called ceramic inorganic piezoelectric materials are widely used. In general, piezoelectric ceramics such as PZT: lead zirconate titanate with high conversion efficiency are used.
In addition, a piezoelectric element that detects a received wave on the high frequency side needs sensitivity with a wider bandwidth. For this reason, an organic piezoelectric body using an organic polymer material such as polyvinylidene fluoride (PVDF) is used as a piezoelectric element suitable for a high frequency and a wide band.
Furthermore, Japanese Patent Application Laid-Open No. 2011-071842 uses MEMS (Micro Electro Mechanical Systems) technology that exhibits an excellent short pulse characteristic and a wide band characteristic, which is excellent in mass productivity and has a small characteristic variation. cMUT is described.
In the present invention, any piezoelectric element material can be preferably used.

<Backing material>
The backing material 4 is provided on the back surface of the piezoelectric element layer 3, and reduces the pulse width of the ultrasonic wave by suppressing excessive vibration, thereby contributing to the improvement of the distance resolution in the ultrasonic diagnostic image.

<Acoustic matching layer>
The acoustic matching layer 2 is provided in order to reduce the difference in acoustic impedance between the piezoelectric element layer 3 and the test object and to efficiently transmit and receive ultrasonic waves.
The resin material for an acoustic wave probe of the present invention is preferably used as a material for an acoustic matching layer because the difference from the acoustic impedance of a living body (1.4 to 1.7 × 10 ⁶ kg / m ² / sec) is small. Can do. The acoustic matching layer preferably contains 10% by mass or more of the resin material for acoustic wave probes of the present invention.

<Acoustic lens>
The acoustic lens 1 is provided to focus the ultrasonic wave in the slice direction using refraction and improve the resolution. In addition, the ultrasonic wave is brought into close contact with the living body to be examined and the ultrasonic wave is matched with the acoustic impedance of the living body (1.4 to 1.7 × 10 ⁶ kg / m ² / sec in the human body), and the acoustic lens 1 The ultrasonic attenuation amount of the device itself is required to be small.
That is, the acoustic lens 1 is made of a material whose sound velocity is sufficiently smaller than the sound velocity of the human body, the attenuation of the ultrasonic wave is small, and the acoustic impedance is close to the value of the human skin. Sensitivity is improved.
The resin material for acoustic wave probes of the present invention can be preferably used as an acoustic lens material.

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

In particular, the acoustic lens obtained from the resin material for acoustic wave probes of the present invention can confirm a remarkable sensitivity improvement effect at an ultrasonic transmission frequency of about 5 MHz or more as a general medical ultrasonic transducer. Particularly significant sensitivity improvement effect can be expected at an ultrasonic transmission frequency of 10 MHz or more.
Hereinafter, an apparatus in which the acoustic lens obtained from the resin material for an acoustic wave probe of the present invention exhibits a function with respect to conventional problems will be described in detail.
In addition, the resin material for acoustic wave probes of the present invention exhibits an excellent effect even for apparatuses other than those described below.

-Ultrasonic probe with cMUT (capacitive micromachined ultrasonic transducer)-
When the cMUT device described in JP 2006-157320 A, JP 2011-71842 A, or the like is used for a transducer array for ultrasonic diagnosis, it is generally compared with a transducer using general piezoelectric ceramics (PZT). Specifically, the sensitivity becomes low.
However, by using an acoustic lens obtained from the resin material for acoustic wave probes of the present invention, it is possible to compensate for the lack of sensitivity of cMUT. Thereby, the sensitivity of the cMUT can be brought close to the performance of the conventional transducer.
Since the cMUT device is manufactured by the MEMS technology, it is possible to provide an ultrasonic probe having a higher productivity and a lower cost than the piezoelectric ceramic probe to the market.

− Photoacoustic wave measurement device using photoacoustic imaging −
Photoacoustic imaging (PAI) described in Japanese Patent Application Laid-Open No. 2013-158435 or the like is a supersonic wave generated when a human body tissue is adiabatically expanded by irradiating light (electromagnetic waves) into the human body. Displays the image of the sound wave or the signal strength of the ultrasonic wave.
Here, since the sound pressure of the ultrasonic wave generated by light irradiation is very small, there is a problem that it is difficult to observe the deep part of the human body.
However, by using an acoustic lens obtained from the resin material for acoustic wave probes of the present invention, an effective effect can be exhibited for this problem.

− Ultrasound endoscope −
Since the ultrasonic wave in the ultrasonic endoscope described in Japanese Patent Application Laid-Open No. 2008-311700 is longer in structure than the body surface transducer due to its structure, the sensitivity of the transducer is improved due to the cable loss. It is a problem. Moreover, it is said that there is no effective sensitivity improvement means for this problem for the following reasons.

First, in the case of an ultrasonic diagnostic apparatus for the body surface, an amplifier circuit, an AD conversion IC, etc. can be installed at the tip of the transducer. On the other hand, since an ultrasonic endoscope is used by being inserted into the body, the installation space for the transducer is narrow, and it is difficult to install an amplifier circuit, an AD conversion IC, or the like at the tip of the transducer.
Secondly, the piezoelectric single crystal employed in the transducer in the ultrasonic diagnostic apparatus for the body surface is difficult to apply to a transducer having an ultrasonic transmission frequency of 7 to 8 MHz or more due to its physical characteristics and process suitability. . However, since endoscope ultrasonic waves are generally probes having an ultrasonic transmission frequency of 7 to 8 MHz or higher, it is difficult to improve sensitivity using a piezoelectric single crystal material.

However, the sensitivity of the endoscope ultrasonic transducer can be improved by using an acoustic lens obtained from the resin material for acoustic wave probes of the present invention.
Even when the same ultrasonic transmission frequency (for example, 10 MHz) is used, the present invention is particularly effective when an acoustic lens obtained from the resin material for an acoustic wave probe of the present invention is used in an ultrasonic transducer for an endoscope. Demonstrated.

  Hereinafter, the present invention will be described in more detail based on examples using ultrasonic waves as acoustic waves. Note that the present invention is not limited to ultrasonic waves, and an acoustic wave having an audible frequency may be used as long as an appropriate frequency is selected in accordance with the object to be examined and measurement conditions. Hereinafter, room temperature means 25 ° C.

[Example]
<Resin sheet No. Production of 101>
50. Low-density polyethylene (manufactured by Nippon Polyethylene, trade name: Novatec LD LJ802) and 50 parts by mass of polysiloxane (manufactured by Gelest, trade name: DMS-T53, trimethylsiloxy-terminated polydimethylsiloxane, weight average molecular weight 204,000) 5 parts by mass and 0.5 parts by mass of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (product name: TC-8, manufactured by Momentive Performance Materials Japan GK) Introduced into a kneader heated to 160 ° C ("Laboplast Mill Micro (trade name) manufactured by Toyo Seiki Co., Ltd.)" Further, secondary crosslinking was performed at 200 ° C. for 2 hours to produce a milky white resin sheet No. 101 having a thickness of 2 mm. It was.

<Resin sheet No. Production of 102 to 119 and c11 to c15>
Resin sheet No. was changed except that the resin composition and kneading temperature were changed as shown in Table 1 below. In the same manner as the production of 101, resin sheet No. 102-118 and c11-c15 were produced.
Resin sheet No. 119 is a resin sheet having a composition described in Table 1 below. After kneading and press-molding in the same manner as in the production of 101, UV light (wavelength 365 nm, UV intensity 300 mW / cm ² , integrated light quantity 2,000 mJ / cm ² ) was used for 10 seconds instead of secondary crosslinking at 200 ° C. It was produced by irradiating and curing.

<Evaluation of physical properties, ultrasonic characteristics and chemical resistance>
Resin sheet No. produced above. The following evaluation was performed for 101 to 119 and c11 to c15.
In addition, resin sheet No. 101 to 119 were not dissolved in hexafluoroisopropanol (HFIP), and it was confirmed that a composite resin in which the vinyl polymer (A) and the polysiloxane (B) were bonded to each other was formed.

1. Density With respect to the obtained resin sheet, the density at 25 ° C. was determined according to the density measurement method of Method A (submersion method) described in JIS K7112 (1999). An electronic hydrometer (manufactured by Alpha Mirage, trade name: SD- 200L).

2. Sonic velocity With respect to the obtained resin sheet, the sonic velocity at 25 ° C. was measured in accordance with JIS Z2353 (2003) using a single-around sonic velocity measuring device (trade name: UVM-2 type, manufactured by Ultrasonic Industry Co., Ltd.).
The sound velocity at 25 ° C. of the vinyl polymer (A) and polysiloxane (B) was also measured in the same manner as the resin sheet.

3. Acoustic impedance The acoustic impedance was determined from the product of the density and sound velocity measured above.

4). Acoustic wave (ultrasonic) sensitivity An ultrasonic probe (Japan probe) outputs a 5 MHz sine wave signal (1 wave) output from an ultrasonic oscillator (trade name: Function generator “FG-350”, manufactured by Iwatsu Measurement Co., Ltd.). And an ultrasonic pulse wave having a center frequency of 5 MHz was generated from the ultrasonic probe in water. The amplitude of the generated ultrasonic wave before and after passing through the obtained resin sheet is measured by an ultrasonic receiver (manufactured by Matsushita Electric Industrial Co., Ltd., trade name: oscilloscope “VP-5204A”) at a water temperature of 25 ° C. By comparing the acoustic wave (ultrasonic wave) sensitivity, the acoustic wave (ultrasonic wave) attenuation amount of each material was compared.
The acoustic wave (ultrasonic wave) sensitivity is a numerical value given by the following calculation formula.
In the following calculation formula, Vin represents a voltage peak value of an input wave generated by the ultrasonic oscillator and having a half-value width of 50 nsec or less. Vs is obtained when the generated acoustic wave (ultrasonic wave) passes through one surface of the resin sheet and the ultrasonic oscillator receives the acoustic wave (ultrasonic wave) reflected from the other surface of the resin sheet. Represents a voltage value. The higher the acoustic wave (ultrasonic wave) sensitivity, the smaller the acoustic wave (ultrasonic wave) attenuation amount.
Acoustic wave (ultrasound) sensitivity = 20 x Log (Vs / Vin)

The acoustic wave (ultrasonic wave) sensitivity was evaluated according to the following evaluation criteria. In this test, an evaluation “C” or higher is an acceptable level.
(Evaluation criteria)
AA: -68 dB or more A: -70 dB or more but less than -68 dB B: -72 dB or more but less than -70 dB C: -74 dB or more but less than -72 dB D: less than -74 dB

5). Chemical resistance The obtained resin sheet was immersed in an aqueous peracetic acid solution (trade name: Esside, manufactured by FUJIFILM Corporation) adjusted to 45 ° C while replacing with a new peracetic acid aqueous solution every 40 hours for a total of 160 hours. Soaked. Tensile tests (based on the method of JIS K6251 (2004), dumbbell-shaped test pieces) were performed on the resin sheets before and after the immersion, and each elongation at break was calculated by the following formula.
Elongation at break (%) = (length of sample at break−length of sample before test) / length of sample before test
× 100%
The ratio of the breaking elongation after immersion to the breaking elongation before immersion was calculated and evaluated according to the following evaluation criteria. In this test, an evaluation “G” or higher is an acceptable level.
(Evaluation criteria)
E: 60% or more G: 30% or more and less than 60% P: Less than 30%

  The composition of the resin, kneading temperature, physical properties of the resin sheet, and evaluation results are summarized in Table 1 below.

<Notes on Table 1>
[Component (A) Vinyl Polymer]
HDPE: high density polyethylene, manufactured by Nippon Polyethylene Co., Ltd., trade name: Novatec HD HJ360 (MFR 5.5 g / 10 min., Sound velocity 2,430 m / s)
LDPE: Low density polyethylene, manufactured by Nippon Polyethylene Co., Ltd., trade name: Novatec LD LJ802 (MFR 22 g / 10 min., Sound velocity 2,000 m / s)
LLDPE: linear low density polyethylene (random copolymer of ethylene and α-olefin), manufactured by Nippon Polyethylene Co., Ltd., trade name: Novatec LL UJ960 (MFR 5 g / 10 min., Speed of sound 1,970 m / s)
PP: polypropylene, manufactured by Nippon Polypro Co., Ltd., trade name: Novatec PP MA3 (MFR 11 g / 10 min., Sound velocity 2,430 m / s)
PMP: Polymethylpentene, manufactured by Mitsui Chemicals, Inc., trade name: TPX DX231 (MFR 100 g / 10 min., Speed of sound 2,050 m / s)
PMMA: Polymethacrylic acid ester, manufactured by Mitsubishi Rayon Co., Ltd., trade name: Acrypet VH (MFR 19.5 g / 10 min., Speed of sound 2,560 m / s)
PVC: polyvinyl chloride, manufactured by Shin-Etsu Polymer Co., Ltd., trade name: Shin-Etsu PVC compound TZ-20B (MFR 3.3 g / 10 min., Sound velocity 2,200 m / s)
CPE: Chlorinated polyethylene, manufactured by Showa Denko KK, trade name: Eraslen 301MA (MFR 1.5 g / 10 min., Sound velocity 2,360 m / s)
EEA: Ethylene-ethyl acrylate copolymer, copolymerization ratio is ethylene: ethyl acrylate = 88: 12, manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: Elvalloy AC 2112AC (MFR 11 g / 10 min., Sound velocity 1 , 970m / s)
EVA: ethylene-vinyl acetate copolymer, copolymerization ratio by mass: ethylene: vinyl acetate = 72: 28, manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: EVAFLEX EV250 (MFR 15 g / 10 min., Sound velocity 1,890 m / S)
PS: polystyrene, manufactured by PS Japan, trade name: PSJ polystyrene HF77 (MFR 7.5 g / 10 min., Speed of sound 2,290 m / s)
AS: acrylonitrile-styrene copolymer, copolymerization ratio is acrylonitrile: styrene = 30: 70 by mass ratio, manufactured by Asahi Kasei Chemicals Corporation, trade name: Stylac AS 767 (MFR 12.5 g / 10 min., Sound velocity 2,330 m / s )
PBd: cis-1,4-polybutadiene, manufactured by JSR Corporation, trade name: BR01 (MFR 13 g / 10 min., Speed of sound 1,530 m / s)
[Component (B) Polysiloxane]
DMS-T53, DMS-T46, DMS-T61: all trade names, manufactured by Gelest, trimethylsiloxy-terminated polydimethylsiloxane DMS-V52: trade names, manufactured by Gelest, vinyl-terminated polydimethylsiloxane PMM-1043: trade names, Gelest, Phenylmethylsiloxane-dimethylsiloxane copolymer FMS-141: trade name, Gelest, poly (3,3,3-trifluoropropylmethylsiloxane)
[Component (C1) Organic peroxide]
TC-8: Trade name, manufactured by Momentive Performance Materials Japan GK, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane [component (C2) photoradical polymerization initiator]
Irg. 184: 1-hydroxy-cyclohexyl-phenyl ketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals)

“-”: Indicates that the component is not contained.
Content: The unit is mass%.
In addition, No. The kneading temperatures of 101 to 117 and 119 are both higher by 10 ° C. or more than the melting points of the components (A) and (B).

From Table 1, resin sheet No. for acoustic probe of this invention. 101 to 119 show that the acoustic impedance is close to the value of the living body, the acoustic wave attenuation is reduced, and the chemical resistance is excellent. Furthermore, the resin sheet for acoustic wave probe No. Compared with 118 and 119, the resin sheet No. for acoustic wave probe. It can be seen that the acoustic wave probe resin sheets 101 to 117 reduce the acoustic wave attenuation at a higher level. This is the resin sheet No. for acoustic wave probe. In 118, the vinyl polymer (A) and the polysiloxane (B) are bonded without being melted by heat, and the resin sheet No. In No. 119, the secondary crosslinking by UV irradiation is performed in a state where the vinyl polymer (A) and the polysiloxane (B) are thermally melted, whereas the resin sheet No. In the 101-117 resin sheet for acoustic wave probes, it is considered that the vinyl polymer (A) and the polysiloxane (B) are thermally melted and subjected to secondary crosslinking by heat.
On the other hand, the resin sheet No. for acoustic wave probe of the comparative example. c11 is a sheet formed by bonding a vinyl copolymer, and the acoustic wave probe resin sheet c12 of the comparative example is a sheet formed by bonding polysiloxane. These resin sheets No. c11 and c12 were inferior because the acoustic impedance was far from that of the living body.
In addition, the resin sheet No. for comparison acoustic wave probe. Although c13 contains a polysiloxane and a vinyl copolymer, they are not bonded to each other. This resin sheet No. c13 was inferior in acoustic wave sensitivity.
Comparative resin sheet for acoustic wave probe No. c14 is formed from poly (meth) acrylic acid ester. This resin sheet No. c14 has an acoustic impedance far from the value of the living body, is inferior, and has poor chemical resistance.
Comparative resin sheet for acoustic wave probe No. c15 is a sheet formed by bonding polybutadiene, which is a vinyl copolymer not defined in the present invention, and polysiloxane. This resin sheet No. c15 has an acoustic impedance far from the value of the living body and is inferior, and the acoustic wave sensitivity and chemical resistance are also insufficient.

  From this result, it is understood that the acoustic wave probe resin of the present invention and the acoustic wave probe resin material of the present invention are useful for medical members. It can also be seen that the resin for acoustic wave probes of the present invention and the resin material for acoustic wave probes of the present invention can be suitably used for acoustic lenses of acoustic wave probes, acoustic wave measuring devices, and ultrasonic diagnostic devices. . In particular, the acoustic wave probe resin of the present invention and the acoustic wave probe resin material of the present invention have sensitivity in an acoustic wave probe, a photoacoustic wave measuring apparatus, and an ultrasonic endoscope using cMUT as an ultrasonic diagnostic transducer array. It can be suitably used for the purpose of improvement.

DESCRIPTION OF SYMBOLS 1 Acoustic lens 2 Acoustic matching layer 3 Piezoelectric element layer 4 Backing material 7 Case 9 Code 10 Ultrasonic probe (probe)

Claims (14)

A resin for an acoustic wave probe comprising a vinyl polymer (A), a polysiloxane (B), an organic peroxide (C1) and / or a radical photopolymerization initiator (C2),
The vinyl polymer (A) is polyethylene, polypropylene, polymethylpentene, poly (meth) acrylate ester, polyvinyl chloride, chlorinated polyethylene, ethylene- (meth) acrylate ester copolymer, ethylene-vinyl acetate. A resin for an acoustic wave probe selected from a copolymer, polystyrene, and an acrylonitrile-styrene copolymer. A resin material for an acoustic wave probe comprising a resin in which a vinyl polymer (A) and a polysiloxane (B) are bonded to each other,
The vinyl polymer (A) is polyethylene, polypropylene, polymethylpentene, poly (meth) acrylate, polyvinyl chloride, chlorinated polyethylene, ethylene- (meth) acrylate copolymer, ethylene-vinyl acetate. A resin material for an acoustic wave probe selected from a copolymer, polystyrene, and an acrylonitrile-styrene copolymer.   The mass ratio of the polysiloxane (B) to the vinyl polymer (A) is vinyl polymer (A): polysiloxane (B) = 1: 99 to 99: 1. Resin material for acoustic wave probes.   The resin material for an acoustic wave probe according to claim 2 or 3, wherein the vinyl polymer (A) and the polysiloxane (B) are thermally melted. The sound velocity at 25 ° C is 1,800 m / s or less, and the acoustic impedance is 1.20 x 10 ^{6 to} 1.80 x 10 ⁶ kg / m ² / s. The resin material for an acoustic wave probe according to Item 1. The acoustic wave according to claim 5, wherein the acoustic velocity at 25 ° C. is 1,600 m / s or less and the acoustic impedance is 1.30 × 10 ^{6 to} 1.70 × 10 ⁶ kg / m ² / s. Resin material for probes.   The step of reacting the melted vinyl polymer (A) with the polysiloxane (B) using an organic peroxide (C1) and / or a radical photopolymerization initiator (C2). The manufacturing method of the resin material for acoustic wave probes of any one of 2-6.   The acoustic lens which consists of the resin material for acoustic wave probes of any one of Claims 2-6.   The acoustic wave probe which has an acoustic lens and / or an acoustic matching layer which consist of the resin material for acoustic wave probes of any one of Claims 2-6.   An ultrasonic probe comprising a capacitive micromachine ultrasonic transducer as an ultrasonic transducer array and the acoustic lens according to claim 8.   An acoustic wave measuring apparatus comprising the acoustic wave probe according to claim 9.   An ultrasonic diagnostic apparatus comprising the acoustic probe according to claim 9.   A photoacoustic wave measuring apparatus comprising the acoustic lens according to claim 8.   An ultrasonic endoscope comprising the acoustic lens according to claim 8.

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