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EP-3517044-B1 - COMPOSITION FOR ACOUSTIC WAVE PROBE, AND SILICONE RESIN FOR ACOUSTIC WAVE PROBE, ACOUSTIC WAVE PROBE, AND ULTRASONIC WAVE PROBE EACH USING SAME, AND ACOUSTIC WAVE MEASUREMENT DEVICE, ULTRASONIC DIAGNOSTIC DEVICE, PHOTOACOUSTIC WAVE MEASUREMENT DEVICE, AND ULTRASONIC ENDOSCOPE

EP3517044B1EP 3517044 B1EP3517044 B1EP 3517044B1EP-3517044-B1

Inventors

  • NAKAI, YOSHIHIRO
  • HASHIMOTO, ATSUSHI

Dates

Publication Date
20260506
Application Date
20170914

Claims (15)

  1. A composition for an acoustic wave probe, comprising: polysiloxane (A) that has a vinyl group and a phenyl group; polysiloxane (B) that has two or more Si-H groups in a molecular chain; a titanium oxide particle (C); and a silica particle (D), wherein at least one of the titanium oxide particle (C) or the silica particle (D) is a particle subjected to surface treatment, and wherein an average primary particle diameter of the component (C) measured by transmission electron microscopy is 100 to 300 nm.
  2. The composition for an acoustic wave probe according to claim 1, wherein 0.1 to 60 parts by mass in total of the component (C) and the component (D) are contained in 100 parts by mass in total of the components (A) to (D), and wherein 10 to 99.4 parts by mass of the component (A) and 0.5 to 90 parts by mass of the component (B) are preferably contained in 100 parts by mass in total of the components (A) to (D).
  3. The composition for an acoustic wave probe according to claim 1 or 2, wherein the component (C) is a particle subjected to surface treatment using a silicon compound.
  4. The composition for an acoustic wave probe according to any one of claims 1 to 3, wherein the component (D) is a particle subjected to surface treatment using a silicon compound, and wherein the component (D) is preferably a particle subjected to surface treatment using a silane compound.
  5. The composition for an acoustic wave probe according to claim 4, wherein the component (D) is a particle subjected to surface treatment using a trimethylsilylating agent, and wherein a degree of methanol hydrophobicity of the component (D) subjected to surface treatment is preferably 40% to 80% by mass and wherein the methanol hydrophobicity is calculated using the following equation: mass % = X / 50 + X × 100 X = the amount of methanol in gram added dropwise until the whole sample settles.
  6. The composition for an acoustic wave probe according to claim 4 or 5, wherein the component (D) subjected to surface treatment is spherical, wherein the Wardell's sphericity of a primary particle of the component (D) is 0.9 to 1, and wherein the Wardell's sphericity is an index obtained by measuring the sphericity of a particle as (diameter of circle equal to projection area of particle)/(diameter of minimum circle circumscribing projection image of particle).
  7. The composition for an acoustic wave probe according to any one of claims 1 to 6, wherein a mass average molecular weight of the component (A) is from 20,000 to 200,000, wherein the mass average molecular weight of the component (A) is preferably from 40,000 to 150,000, and wherein the mass average molecular weight refers to a value in terms of polystyrene measured through gel permeation chromatography.
  8. The composition for an acoustic wave probe according to any one of claims 1 to 7, wherein the component (B) is a compound containing a phenyl group, and preferably further comprising: 0.00001 to 0.01 parts by mass of platinum or a platinum compound with respect to 100 parts by mass in total of the components (A) to (D).
  9. A silicone resin for an acoustic wave probe which is obtained by vulcanizing the composition for an acoustic wave probe according to any one of claims 1 to 8.
  10. An acoustic wave probe comprising: an acoustic lens and/or an acoustic matching layer made of the silicone resin for an acoustic wave probe according to claim 9.
  11. An ultrasound probe comprising: a capacitive micromachined ultrasonic transducer as an ultrasonic transducer array; and an acoustic lens made of the silicone resin for an acoustic wave probe according to claim 9.
  12. An acoustic wave measurement apparatus comprising: the acoustic wave probe according to claim 10.
  13. An ultrasound diagnostic apparatus comprising: the acoustic wave probe according to claim 10.
  14. A photoacoustic wave measurement apparatus comprising: an acoustic lens made of the silicone resin for an acoustic wave probe according to claim 9.
  15. An ultrasound endoscope comprising: an acoustic lens made of the silicone resin for an acoustic wave probe according to claim 9.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for an acoustic wave probe, a silicone resin for an acoustic wave probe formed of the same, an acoustic wave probe, and an ultrasound probe. Furthermore, the present invention relates to an acoustic wave measurement apparatus, an ultrasound diagnostic apparatus, a photoacoustic wave measurement apparatus, and an ultrasound endoscope. 2. Description of the Related Art In an acoustic wave measurement apparatus, an acoustic wave probe is used which irradiates a test object or a site (hereinafter, simply referred to as a subject) with an acoustic wave, receives a reflected wave (echo) thereof, and outputs a signal. An electrical signal converted from the reflected wave which has been received by this acoustic wave probe is displayed as an image. Accordingly, the interior of the test object is visualized and observed. Acoustic waves, such as ultrasonic waves and photoacoustic waves, which have an appropriate frequency in accordance with a test object and/or measurement conditions, are selected as the acoustic waves. For example, an ultrasound diagnostic apparatus transmits an ultrasonic wave to the interior of a test object, receives the ultrasonic wave reflected by the tissues inside the test object, and displays the received ultrasonic wave as an image. A photoacoustic wave measurement apparatus receives an acoustic wave radiated from the interior of a test object due to a photoacoustic effect, and displays the received acoustic wave as an image. The photoacoustic effect is a phenomenon in which an acoustic wave (typically an ultrasonic wave) is generated through thermal expansion after a test object absorbs an electromagnetic wave and generates heat in a case where the test object is irradiated with an electromagnetic wave pulse of visible light, near infrared light, microwave, or the like. An acoustic wave measurement apparatus performs transmission and reception of an acoustic wave on a living body (typically, the human body) which is a test object. Therefore, it is necessary to fulfill requirements such as consistency in the acoustic impedance within the living body (typically a human body) and/or a decrease in acoustic attenuation. For example, a probe for an ultrasound diagnostic apparatus (also referred to as an ultrasound probe) which is a kind of acoustic wave probe comprises a piezoelectric element which transmits and receives an ultrasonic wave and an acoustic lens which is a portion coming into contact with a living body. An ultrasonic wave oscillating from the piezoelectric element is incident on the living body after being transmitted through the acoustic lens. In a case where the difference between acoustic impedance (density × acoustic velocity) of the acoustic lens and acoustic impedance of the living body is large, the ultrasonic wave is reflected by the surface of the living body. Therefore, the ultrasonic wave is not efficiently incident on the living body. For this reason, it is difficult to obtain a favorable resolution. In addition, it is desirable that ultrasonic attenuation of the acoustic lens is low in order to transmit and receive the ultrasonic wave with high sensitivity. For this reason, a silicone resin of which the acoustic impedance is close to the acoustic impedance of a living body (in the case of a human body, 1.40 × 106 to 1.70 × 106 kg/m2/sec) and which has a low ultrasonic attenuation is used as a material of the acoustic lens. For example, JP2016-107075A discloses a composition for an acoustic wave probe which includes a polysiloxane mixture containing polysiloxane having a vinyl group, polysiloxane having two or more Si-H's in a molecular chain, and inorganic compound particles having a particular particle diameter and specific weight. JP2016-107075A discloses that an acoustic wave probe is formed using a silicone resin obtained by vulcanizing this resin composition, thereby suppressing acoustic attenuation or improving mechanical characteristics. US20170252465A1 describes a composition for an acoustic wave probe comprising a polysiloxane mixture and one or more inorganic compound particles, wherein the average primary particle diameter of the inorganic compound particles is less than 25 nm. US 20020006079A1 describes an ultrasonic probe comprising a piezoelectric element, an acoustic lens, wherein the acoustic lens is formed by vulcanization by adding a vulcanizing agent to a composition including silica particles. SUMMARY OF THE INVENTION The invention disclosed in JP2016-107075A is an invention for improving characteristics in which the acoustic attenuation is decreased according to the acoustic impedance of the acoustic wave probe which is set within a predetermined numerical value range, or the resin hardness is improved so that the mechanical strength is also improved; which are required for an acoustic wave probe used for a living body. However, recently, further