JPWO2016088699

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DESCRIPTION JPWO2016088699
Abstract: A polysiloxane mixture having a vinyl group, a polysiloxane having two or more Si-H
groups in a molecular chain, and a polysiloxane mixture containing one or more inorganic
compound particles, wherein the inorganic compound particles have an average primary particle
diameter Provided is a composition for an acoustic wave probe which is less than 25 nm and is
selected from the group consisting of magnesium oxide, titanium oxide, iron oxide, zinc oxide,
zirconium oxide, barium oxide, tin oxide and ytterbium oxide. The composition for an acoustic
wave probe can significantly improve the hardness and mechanical strength (tensile breaking
strength, tensile breaking elongation, tear strength and abrasion resistance) of a silicone resin
while keeping the amount of acoustic wave attenuation low. It becomes. In addition, the
sensitivity of an ultrasonic probe, a photoacoustic wave measurement apparatus, and an
ultrasonic endoscope that uses cMUT as a transducer for ultrasonic diagnosis can be improved.
Composition for acoustic wave probe, silicone resin for acoustic wave probe using the same,
acoustic wave probe and ultrasonic probe, acoustic wave measurement device, ultrasonic
diagnostic device, photoacoustic wave measurement device, and ultrasonic endoscope
[0001]
The present invention relates to a composition for an acoustic wave probe and a silicone resin for
an acoustic wave probe using the same, an acoustic wave probe and an ultrasonic probe.
Furthermore, the present invention relates to an acoustic wave measurement device, an
ultrasonic diagnostic device, a photoacoustic wave measurement device, and an ultrasonic
endoscope.
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[0002]
In the acoustic wave measuring apparatus, an acoustic wave probe is used which irradiates an
acoustic wave to an object or a part (hereinafter simply referred to as an object), receives a
reflected wave (echo), and outputs a signal. The electric signal converted from the reflected wave
received by the acoustic wave probe is displayed as an image. Thereby, the inside of the object is
visualized and observed.
[0003]
As the acoustic wave, an appropriate frequency is selected according to an object to be examined,
measurement conditions, and the like, such as an ultrasonic wave and a photoacoustic wave. For
example, the ultrasound diagnostic apparatus transmits ultrasound toward the inside of the
subject, receives ultrasound reflected by the tissue inside the subject, and displays the ultrasound
as an image. The photoacoustic wave measuring apparatus receives an acoustic wave emitted
from the inside of the subject by the photoacoustic effect and displays it as an image. The
photoacoustic effect is an acoustic wave (typical) when the subject absorbs the electromagnetic
wave, generates heat, and thermally expands when the subject is irradiated with an
electromagnetic wave pulse such as visible light, near infrared light, or microwave. ) Is a
phenomenon that occurs. Since the acoustic wave measuring apparatus transmits and receives
acoustic waves to and from a living body to be tested, it is required to satisfy requirements such
as matching of acoustic impedance with the living body and reduction of acoustic wave
attenuation.
[0004]
For example, a probe for an ultrasonic diagnostic apparatus (also referred to as an ultrasonic
probe), which is a type of acoustic wave probe, includes a piezoelectric element that transmits
and receives an ultrasonic wave and an acoustic lens that is a portion in contact with a living
body. The ultrasonic wave oscillated from the piezoelectric element passes through the acoustic
lens and is incident on the living body. If the difference between the acoustic impedance (density
x speed of sound) of the acoustic lens and the acoustic impedance of the living body is large, the
ultrasonic wave is reflected on the living body surface, so the ultrasonic wave is not efficiently
incident in the living body and high resolution is obtained. Is difficult. In addition, in order to
transmit and receive ultrasonic waves with high sensitivity, it is desirable that the amount of
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ultrasonic attenuation of the acoustic lens be small. For this reason, as one of the materials of the
acoustic lens, silicone resin having a small amount of ultrasonic attenuation is close to the
acoustic impedance of a living body (1.4 to 1.7 × 10 6 kg / m 2 / sec). Mainly used.
[0005]
For example, in Patent Document 1, it is proposed to add a thermoplastic resin powder such as
an inorganic filler and nylon powder to silicone rubber as a composition for an acoustic lens.
Further, since the acoustic lens is used in contact with the subject, the acoustic lens is required to
have mechanical strength that can withstand long-term use. Therefore, in Patent Document 2, as
a composition for an acoustic lens satisfying acoustic lens characteristics (acoustic impedance,
ultrasonic attenuation amount, mechanical strength, etc.), a composition containing a powder
such as silicone rubber, ytterbium oxide and silica particles is proposed. It is done.
[0006]
JP-A-62-011897 JP-A-2005-125071
[0007]
Silicone resins are soft alone and have low mechanical strength.
Therefore, in order to improve the hardness and mechanical strength, the inorganic filler (also
referred to as inorganic filler) and the vinyl group-containing resin (also referred to as
reinforcing agent) are blended while increasing the molecular weight of the vinyl silicone resin at
both ends. It is done. However, in order to achieve the required mechanical strength, the addition
amount of the inorganic filler and the vinyl group-containing resin to the silicone resin inevitably
increases, and conversely, the silicone resin becomes large in acoustic wave attenuation. was
there. Therefore, it has been difficult for conventional silicone resins to satisfy all of high resin
hardness and mechanical strength and reduction of acoustic wave attenuation at high levels.
Therefore, in the present invention, in view of the above circumstances, the hardness and
mechanical strength (tensile breaking strength, tensile breaking elongation, tear strength and
abrasion resistance) of the silicone resin are greatly improved while keeping the acoustic wave
attenuation low. It is an object of the present invention to provide a composition for an acoustic
wave probe which can be used, a silicone resin for an acoustic wave probe using the same, an
acoustic wave probe, an acoustic wave measurement apparatus and an ultrasonic diagnostic
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apparatus.
[0008]
Another object of the present invention is to provide an ultrasonic probe which can use
capacitive micromachined ultrasonic transducers (cMUT: Capacitive Micromachined Ultrasonic
Transducers) having insufficient sensitivity as a transducer array for ultrasonic diagnosis.
Further, a composition for an acoustic wave probe capable of improving the sensitivity in a
photoacoustic wave measurement apparatus in which the sensitivity is low because the amount
of ultrasonic waves generated by the photoacoustic wave is small and observation of the deep
part of the human body is difficult. And providing a silicone resin for an acoustic wave probe. In
addition to this, it is possible to improve the sensitivity in an ultrasonic endoscope in which the
sensitivity is low because the signal line cable is longer than that for body surface, and it is
difficult to improve the sensitivity in terms of structure, physical characteristics and process
suitability. It is an object of the present invention to provide a possible composition for an
acoustic wave probe and a silicone resin for an acoustic wave probe.
[0009]
The present inventors examined the inorganic compound to be added to the silicone resin
composition for the composition for acoustic wave probe, and as a result, by containing a specific
inorganic compound particle having a particle diameter of a specific range, It has been found that
the above problems can be solved, and the present invention has been made based on this
finding.
[0010]
The above problems are solved by the following means.
<1> A composition for an acoustic wave probe comprising a polysiloxane mixture having a vinyl
group, a polysiloxane having two or more Si-H groups in a molecular chain, and a polysiloxane
mixture containing one or more inorganic compound particles. An acoustic wave probe wherein
the inorganic compound particles have an average primary particle size of less than 25 nm and
are selected from the group consisting of magnesium oxide, titanium oxide, iron oxide, zinc oxide,
zirconium oxide, barium oxide, tin oxide and ytterbium oxide Composition. The composition for
acoustic wave probes as described in <1> which contains 10-60 mass parts of inorganic
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compound particle ¦ grains whose average primary particle diameter is less than 25 nm in a total
of 100 mass parts of a <2> polysiloxane mixture. 10 to 99.4 parts by mass of a polysiloxane
having a vinyl group and 0.5 to 0.5 part of a polysiloxane having two or more Si-H groups in a
molecular chain in 100 parts by mass of a total of the <3> polysiloxane mixture The composition
for acoustic wave probes as described in <1> or <2> which contains 90 mass parts. The
composition for acoustic wave probes as described in any one of <1>-<3> by which the inorganic
compound particle ¦ grains whose average primary particle diameter is less than 25 nm are
surface-treated by the silane compound. The composition for acoustic wave probes as described
in any one of <1>-<4> whose mass mean molecular weights of the polysiloxane which has a <5>
vinyl group are 20,000-200,000. The composition for acoustic wave probes as described in any
one of <1>-<5> whose mass mean molecular weights of the polysiloxane which has a <6> vinyl
group are 40,000-150,000. The composition for acoustic wave probes as described in any one of
<1>-<6> which contains 0.00001-0.05 mass part of platinum or a platinum compound with
respect to 100 mass parts of <7> polysiloxane mixtures. The silicone resin for acoustic wave
probes which hardened the composition for acoustic wave probes as described in any one of <8>
<1>-<7>. <9> An acoustic wave probe comprising an acoustic lens comprising a silicone resin for
an acoustic wave probe according to <8> and / or an acoustic matching layer comprising a
silicone resin for an acoustic wave probe according to <8>. <10> An ultrasonic probe comprising:
a capacitive micromachined ultrasonic transducer as an ultrasonic transducer array; and an
acoustic lens comprising the silicone resin for an acoustic wave probe according to <8>. The
acoustic wave measuring apparatus provided with the acoustic wave probe as described in <11>
<9>. The ultrasonic diagnostic apparatus provided with the acoustic wave probe as described in
<12> <9>.
The photoacoustic wave measuring apparatus provided with the acoustic lens which comprises
the silicone resin for acoustic wave probes as described in <13> <8>. The ultrasonic endoscope
provided with the acoustic lens which comprises the silicone resin for acoustic wave probes as
described in <14> <8>.
[0011]
In the description of the present specification, unless otherwise specified, when a plurality of
groups having the same symbol is present in a general formula representing a compound, these
may be the same as or different from each other, and each group specifies The group (eg, an
alkyl group) may further have a substituent. Moreover, "Si-H group" means a group having three
bonding hands on a silicon atom, but the description of the bonding hand is omitted and the
notation is simplified. Moreover, in this specification, "-" is used in the meaning included
including the numerical value described before and after that as a lower limit and an upper limit.
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In addition, the mass mean molecular weight in this specification is a measured value
(polystyrene conversion) by gel permeation chromatography (GPC) unless there is particular
notice.
[0012]
According to the present invention, the hardness and mechanical strength (tensile breaking
strength, tensile breaking elongation, tear strength and abrasion resistance) of the silicone resin
are significantly improved while keeping the acoustic wave (particularly preferably ultrasonic
wave) attenuation low. The present invention can provide a composition for an acoustic wave
probe that can be used, a silicone resin for an acoustic wave probe using the same, an acoustic
wave probe, an acoustic wave measurement device, and an ultrasonic diagnostic device. In
addition, it is possible to provide an ultrasonic probe using cMUT as a transducer array for
ultrasonic diagnosis, a photoacoustic wave measuring apparatus, and a silicone resin for an
acoustic wave probe capable of improving the sensitivity in an ultrasonic endoscope.
[0013]
Such an effect is considered to be because the inorganic compound particles having a small
average primary particle diameter function as a stopper when mechanical stress is applied to the
silicone resin for an acoustic wave probe. In particular, since the distance between particles is
reduced due to the small average primary particle diameter, the function as a stopper is more
exhibited, and the tear strength of the silicone resin is significantly improved. As a result, an
increase in the amount of acoustic wave attenuation is suppressed, and the hardness and
mechanical strength (tensile breaking strength, tensile breaking elongation, tear strength and
abrasion resistance) of the silicone resin for an acoustic wave probe are considered to be
improved. The above and other features and advantages of the present invention will become
more apparent from the following description with reference to the accompanying drawings as
appropriate.
[0014]
FIG. 1 is a perspective transmission view of an example of a convex ultrasonic probe which is an
embodiment of an acoustic wave probe.
[0015]
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<< Composition for Acoustic Wave Probe >> The composition for acoustic wave probe of the
present invention (hereinafter, also simply referred to as a composition).
And the like) is a composition for an acoustic wave probe containing a polysiloxane mixture
having a vinyl group, a polysiloxane having two or more Si-H groups in a molecular chain, and a
polysiloxane mixture containing at least one inorganic compound particle. The inorganic
compound particles have an average primary particle size of less than 25 nm and are selected
from the group consisting of magnesium oxide, titanium oxide, iron oxide, zinc oxide, zirconium
oxide, barium oxide, tin oxide and ytterbium oxide.
[0016]
The content of the inorganic compound particles in the total 100 parts by mass of the
polysiloxane mixture is preferably 10 to 60 parts by mass, more preferably 15 to 50 parts by
mass, and still more preferably 20 to 40 parts by mass. In addition, the content of the vinyl
group-containing polysiloxane in the total 100 parts by mass of the polysiloxane mixture is
preferably 10 to 99.4 parts by mass, and the polysiloxane having two or more Si-H groups in the
molecular chain The content is preferably 0.5 to 90 parts by mass. The content of the vinyl
group-containing polysiloxane is more preferably 50 to 90 parts by mass, and the content of the
polysiloxane having two or more Si-H groups in the molecular chain is more preferably 1 to 50
parts by mass. preferable. In addition, a polysiloxane mixture is a mixture which does not contain
the catalyst which carries out the cross-linking polymerization (hardening) of the polysiloxane
which has a vinyl group, and the polysiloxane which has two or more Si-H groups in a molecular
chain. Thus, the polysiloxane mixture contains inorganic compound particles but no catalyst.
Moreover, the total of 100 parts by mass of the polysiloxane mixture means that the total of the
individual components contained in the polysiloxane mixture is 100 parts by mass.
[0017]
Each of the above-mentioned polysiloxanes contained in the polysiloxane mixture may be any
polysiloxane as long as it has two or more Si-H groups in a vinyl group or a molecular chain.
However, in the present invention, a polyorganosiloxane (A) having a vinyl group and a
polyorganosiloxane (B) having two or more Si-H groups in the molecular chain are preferable.
Therefore, in the present invention, a polyorganosiloxane (A) having a vinyl group, a
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polyorganosiloxane (B) having two or more Si-H groups in a molecular chain, and inorganic
compound particles (C) in a polyorganosiloxane mixture The composition which contains at least
as a component is preferable. In the following detailed description, the polysiloxane mixture
contains a polyorganosiloxane (A) having a vinyl group and a polyorganosiloxane (B) having two
or more Si-H groups in the molecular chain, which is a preferred embodiment. Describe what you
are doing. However, each polysiloxane contained in the polysiloxane mixture is not limited to the
polysiloxanes (A) and (B).
[0018]
<Polyorganosiloxane (A) having a vinyl group> The polyorganosiloxane (A) having a vinyl group
used in the present invention (hereinafter, also simply referred to as polyorganosiloxane (A). )
Have two or more vinyl groups in the molecular chain. The polyorganosiloxane (A) having a vinyl
group is, for example, a polyorganosiloxane (a) having a vinyl group at least at both molecular
chain terminals (hereinafter, also simply referred to as polyorganosiloxane (a)), or a molecular
chain. Polyorganosiloxane (b) having at least two -O-Si (CH3) 2 (CH = CH2) in (hereinafter, also
simply referred to as polyorganosiloxane (b). Can be mentioned. Among them,
polyorganosiloxane (a) having vinyl groups at least at both molecular chain terminals is
preferable. The polyorganosiloxane (a) is preferably linear, and the polyorganosiloxane (b) is a
poly having -O-Si (CH 3) 2 (CH = CH 2) bonded to the Si atom constituting the main chain.
Organosiloxanes (b) are preferred.
[0019]
The polyorganosiloxane (A) having a vinyl group is hydrosilylated, for example, by the reaction
with a polyorganosiloxane (B) having two or more Si-H groups in the presence of a platinum
catalyst. The hydrosilylation reaction (addition reaction) forms a crosslinked structure (curing).
[0020]
The content of the vinyl group in the polyorganosiloxane (A) is not particularly limited. From the
viewpoint of forming a sufficient network with each component contained in the acoustic wave
probe composition, for example, the content of the vinyl group is preferably 0.01 to 5 mol%, and
preferably 0.05 to 2 mol. % Is more preferable. Here, the content of the vinyl group is the mol%
of the vinyl group-containing siloxane unit when the total unit constituting the
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polyorganosiloxane (A) is 100 mol%. One vinyl group-containing siloxane unit has 1 to 3 vinyl
groups. Among them, one vinyl group is preferable to one vinyl group-containing siloxane unit.
For example, in the case where the Si̶O units constituting the main chain and all the Si atoms of
the terminal Si have at least one vinyl group, this is 100 mol%.
[0021]
Moreover, it is preferable that polyorganosiloxane (A) has a phenyl group, and content of the
phenyl group of polyorganosiloxane (A) is not specifically limited. From the viewpoint of
mechanical strength when used as a silicone resin for an acoustic wave probe, for example, it is
preferably 1 to 80 mol%, more preferably 2 to 40 mol%. Here, content of a phenyl group is mol%
of a phenyl group containing siloxane unit when all units which comprise polyorganosiloxane (A)
are 100 mol%. One phenyl group-containing siloxane unit has 1 to 3 phenyl groups. Among
them, two phenyl groups are preferable to one phenyl group-containing siloxane unit. For
example, in the case where the Si̶O units constituting the main chain and all the Si atoms of the
terminal Si have at least one phenyl group, it is 100 mol%. In addition, a unit means Si-O unit
which comprises a principal chain, and Si of the terminal.
[0022]
The degree of polymerization and specific gravity are not particularly limited. In addition, silicone
resin for acoustic wave probes obtained (hereinafter, also simply referred to as silicone resin).
The degree of polymerization is preferably 200 to 3,000, more preferably 400 to 2,000, and the
specific gravity is preferably 0.9 to 1.1, from the viewpoint of improvement in mechanical
strength, hardness, chemical stability and the like.
[0023]
The mass average molecular weight of the polyorganosiloxane having a vinyl group is preferably
20,000 to 200,000, more preferably 40,000 to 150,000, in view of mechanical strength,
hardness, and ease of processing. More preferably, 000 to 120,000.
[0024]
For example, GPC apparatus HLC-8220 (manufactured by Tosoh Corp.) is used as mass average
molecular weight, and toluene (manufactured by Shonan Wako Pure Chemical Industries, Ltd.) is
used as an eluent, and TSKgel (registered trademark) G3000HXL + TSKgel (registered trademark)
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as a column. It can measure using RI detector using G2000HXL, the temperature of 23 degreeC,
and the conditions of flow volume 1mL / min.
[0025]
The kinematic viscosity at 25 ° C. is preferably 1 × 10 <−5> to 10 m <2> / s, more preferably
1 × 10 <−4> to 1 m <2> / s, 1 × 10 <−3> It is further preferable that 〜0.5 m <2> / s.
The kinematic viscosity can be determined by measurement at a temperature of 25 ° C. using a
Ubbelohde viscometer (for example, product name SU manufactured by Shibata Kagaku Co., Ltd.)
according to JIS Z8803.
[0026]
The polyorganosiloxane (a) having a vinyl group at least at both molecular chain terminals is
preferably a polyorganosiloxane represented by the following general formula (A).
[0027]
<img class = "EMIRef" id = "461658451-000003" />
[0028]
In formula (A), R <a1> represents a vinyl group, and R <a2> and R <a3> each independently
represent an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group.
Each of x1 and x2 independently represents an integer of 1 or more.
Here, the plurality of R <a2> and the plurality of R <a3> may be the same or different from one
another.
Moreover, each group of R <a2> and R <a3> may further have a substituent.
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[0029]
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 ndecyl.
[0030]
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 are more preferable. The cycloalkyl group is preferably a 3-, 5- or 6membered ring, more preferably a 5- or 6-membered ring. Examples of the cycloalkyl group
include cyclopropyl, cyclopentyl and cyclohexyl.
[0031]
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.
[0032]
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.
[0033]
These alkyl group, cycloalkyl group, alkenyl group and aryl group may have a substituent. Such
substituents include, for example, halogen atoms, alkyl groups, cycloalkyl groups, alkenyl groups,
aryl groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, silyl groups and
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cyano groups. As a group which has a substituent, a halogenated alkyl group is mentioned, for
example.
[0034]
R <a2> and R <a3> each is 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 a methyl group, a vinyl group or a phenyl group preferable. Among them, a methyl group
is preferable, and a methyl group, a vinyl group or a phenyl group is preferable, a methyl group
or a phenyl group is more preferable, and a methyl group is particularly preferable. It is also
preferred that both R <a2> in the repetition of x1 be a phenyl group.
[0035]
The integer of 200-3000 is preferable and, as for x1, the integer of 400-2000 is more preferable.
The integer of 1-3000 is preferable, the integer of 1-1000 is more preferable, the integer of 401000 is further more preferable, and the integer of 40-700 is especially preferable. Moreover, as
another aspect, the integer of 1-3000 is preferable and, as for x1, the integer of 5-1000 is more
preferable.
[0036]
For example, all polyorganosiloxanes having a vinyl group at both molecular chain terminals are
DMS series (for example, DMS-V31, DMS-V31S15, DMS-V33, DMS-V35, DMS- under the trade
name of Gelest, Inc.). V35R, DMS-V41, DMS-V42, DMS-V46, DMS-V51, DMS-V52), PDV series (for
example, PDV-0341, PDV-0346, PDV-0535, PDV-0541, PDV-1631, PDV- 1635, PDV-1641, PDV2335), PMV-9925, PVV-3522, FMV-4031, EDV-2022. In addition, since fumed silica is mix ¦
blended beforehand, DMS-V31 S15 does not need kneading ¦ mixing in a special apparatus.
[0037]
As the polyorganosiloxane (A) having a vinyl group in the present invention, only one type may
be used alone, or two or more types may be used in combination.
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[0038]
<Polyorganosiloxane (B) having two or more Si-H groups in the molecular chain>
Polyorganosiloxane (B) having two or more Si-H groups in the molecular chain used in the
present invention Also simply referred to as polyorganosiloxane (B).
) Have two or more Si-H groups in the molecular chain. By having two or more Si-H groups in the
molecular chain, it is possible to crosslink a polyorganosiloxane having at least two
polymerizable unsaturated groups.
[0039]
The polyorganosiloxane (B) has a linear structure and a branched structure, and is preferably a
linear structure. The mass average molecular weight of the linear structure is preferably 500 to
100,000, and more preferably 1,500 to 50,000, from the viewpoint of mechanical strength and
hardness.
[0040]
The polyorganosiloxane (B) having a linear structure having two or more Si-H groups in the
molecular chain is preferably a polyorganosiloxane represented by the following general formula
(B).
[0041]
<img class = "EMIRef" id = "461658451-00004" />
[0042]
In the general formula (B), R <b1> to R <b3> each independently represent a hydrogen atom, an
alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or -O-Si (R <b5>) 2 (R represents
<b4>).
R <b4> and R <b5> each independently represent a hydrogen atom, an alkyl group, a cycloalkyl
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group, an alkenyl group or an aryl group.
y1 and y2 each independently represent an integer of 1 or more. Here, the plurality of R <b1>,
the plurality of R <b2>, the plurality of R <b3>, the plurality of R <b4> and the plurality of R <b5>
may be identical to or different from each other, and And each group of R <b1> to R <b5> may be
further substituted by a substituent. However, it has two or more Si-H groups in the molecular
chain.
[0043]
The alkyl group, cycloalkyl group, alkenyl group and aryl group at R <b1> to R <b3> have the
same meanings as the alkyl group, cycloalkyl group, alkenyl group and aryl group at R <a2> and
R <a3> The preferred range is also the same.
[0044]
The alkyl group, cycloalkyl group, alkenyl group and aryl group in R <b4> and R <b5> of -O-Si (R
<b5>) 2 (R <b4>) are R <b1> to R <b3 It is synonymous with the alkyl group in>, a cycloalkyl
group, an alkenyl group, and an aryl group, and its preferable range is also the same.
[0045]
R <b1> to R <b3> is preferably a hydrogen atom, an alkyl group, an alkenyl group, an aryl group
or -O-Si (R <b5>) 2 (R <b4>), and a hydrogen atom having 1 to 4 carbon atoms Alkyl group, a
vinyl group, a phenyl group or -O-Si (CH3) 2H is more preferable.
Among them, R <b1> and R <b2> are preferably a hydrogen atom, an alkyl group, an alkenyl
group or an aryl group, more preferably a hydrogen atom or an alkyl group, and still more
preferably a hydrogen atom or a methyl group.
R <b3> is preferably a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or -O-Si (R
<b> <5>) 2 (R <b4>), and a hydrogen atom or -O-Si (CH) 3) 2 H is more preferred.
[0046]
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The integer of 1-2000 is preferable, the integer of 1-50 is more preferable, and the integer of 130 is still more preferable. The integer of 5-2000 is preferable, the integer of 7-1000 is more
preferable, 10-50 are further more preferable, and the integer of 15-30 is especially preferable.
[0047]
As a combination of R <b1> to R <b3>, R <b1> is a hydrogen atom or an alkyl group having 1 to 4
carbon atoms, R <b2> is an alkyl group having 1 to 4 carbon atoms, and R <b3> is A combination
of hydrogen atoms is preferred, and R <b1> is a C1-C4 alkyl group, R <b2> is a C1-C4 alkyl
group, and R <b3> is a combination of hydrogen atoms. In this preferable combination, the
content of the hydrosilyl group represented by y2 / (y1 + y2) is preferably more than 0.1 and
less than 0.6, and more preferably more than 0.1 and less than 0.4.
[0048]
The polyorganosiloxane (B) having a linear structure is, for example, HMS-064 (MeHSiO: 5-7
mol%), which is a methylhydrosiloxane-dimethylsiloxane copolymer (trimethylsiloxane end)
manufactured by Gelest, HMS- 082 (MeHSiO: 7-8 mol%), HMS-301 (MeHSiO: 25-30 mol%), HMS501 (MeHSiO: 50-55 mol%). Here, mol% of MeHSiO is synonymous with what multiplied 100 by
y2 / (y1 + y2) in the preferable combination of said R <b1> -R <b3>.
[0049]
Both linear and branched structures preferably have no vinyl group from the viewpoint of
preventing the progress of the crosslinking reaction in the molecule, and particularly those
having a branched structure do not have a vinyl group. Is preferred.
[0050]
The branched polyorganosiloxane (B) having two or more Si-H groups in the molecular chain has
a branched structure and two or more hydrosilyl groups (Si-H groups).
The specific gravity is preferably 0.9 to 0.95. The polyorganosiloxane (B) having a branched
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structure is preferably one represented by the following average composition formula (b).
[0051]
Average composition formula (b): [Ha (R <b6>) 3-a SiO 1/2] y3 [SiO 4/2] y4
[0052]
Here, R <b6> represents an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group, a
represents 0.1 to 3, and y3 and y4 each independently represent an integer of 1 or more.
[0053]
The alkyl group, cycloalkyl group, alkenyl group and aryl group in R <b6> are the same as the
alkyl group, cycloalkyl group, alkenyl group and aryl group in R <> <a2> and R <a3>, and
preferred ranges Is also the same.
a is preferably 1.
The content of the hydrosilyl group represented by a / 3 is preferably more than 0.1 and less
than 0.6, and more preferably more than 0.1 and less than 0.4.
[0054]
On the other hand, when the polyorganosiloxane (B) having a branched structure is represented
by a chemical structural formula, a polyorganosiloxane in which ̶O̶Si (CH 3) 2 (H) is bonded
to the Si atom constituting the main chain is preferable. Those having a structure represented by
the following general formula (Bb) are more preferable.
[0055]
<img class = "EMIRef" id = "461658451-000005" />
[0056]
In the general formula (Bb), * means to bond to at least the Si atom of siloxane.
03-05-2019
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[0057]
The polyorganosiloxane (B) having a branched structure is, for example, HQM-107 (trade name,
manufactured by Gelest, hydrogenated Q resin), HDP-111 (trade name, manufactured by Gelest,
polyphenyl- (dimethylhydroxy) siloxane (Hydrogen end), [(HMe2SiO) (C6H3Si) O]: 99-100 mol%).
[0058]
The polyorganosiloxane (B) having two or more Si-H groups in the molecular chain used in the
present invention may be used alone or in combination of two or more.
Moreover, you may use combining the polyorganosiloxane (B) of a linear structure, and the
polyorganosiloxane (B) of a branched structure.
[0059]
<Inorganic Compound Particles (C)> The inorganic compound particles (C) used in the present
invention have an average primary particle diameter of less than 25 nm, and are magnesium
oxide, titanium oxide, iron oxide, zinc oxide, zirconium oxide, barium oxide, It is selected from the
group consisting of tin oxide and ytterbium oxide.
[0060]
By adding the inorganic compound particles to the silicone resin, the effect of improving the
acoustic impedance, hardness and mechanical strength of the silicone resin can be obtained,
while the acoustic wave attenuation amount increases with the increase of the addition amount
of the inorganic compound particles.
[0061]
However, in the present invention, by decreasing the average primary particle diameter of the
inorganic compound particles (C) to less than 25 nm, it is possible to suppress an increase in the
amount of acoustic wave attenuation and improve the tear strength of the silicone resin. It seems
that it has become.
03-05-2019
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That is, it is thought that the crack of the silicone resin by mechanical stress is suppressed by the
inorganic compound particle (C) functioning as a stopper.
In particular, since the distance between particles is reduced due to the small average primary
particle diameter, it is presumed that the function as a stopper is more exhibited and the tear
strength of the silicone resin is significantly improved.
[0062]
The average primary particle diameter of the inorganic compound particles (C) used in the
present invention is less than 25 nm from the viewpoint of suppressing the increase in acoustic
wave attenuation of the silicone resin and improving the tear strength, and is more than 3 nm
and less than 25 nm Preferably, it is more than 3 nm and more preferably 20 nm or less, more
preferably more than 3 nm and 15 nm or less.
The smaller the average primary particle diameter is in the above range, the higher the tear
strength and the better the acoustic wave sensitivity, which is preferable.
[0063]
The average primary particle size is described in the catalog of the manufacturer of the inorganic
compound particles.
However, those in which the average primary particle diameter is not described in the catalog or
those newly manufactured can be determined by averaging the particle diameters measured by
Transmission Electron Microscopy (TEM).
That is, for one particle of an electron micrograph taken by TEM, the minor axis and the major
axis are measured, and the average value is determined as the particle size of one particle. In the
present specification, the particle sizes of 300 or more particles are averaged to obtain an
average primary particle size. Moreover, when the surface treatment mentioned later is given to
the inorganic compound particle ¦ grain (C), the average primary particle diameter in the state by
03-05-2019
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which surface treatment was carried out is meant.
[0064]
The specific gravity of the inorganic compound particles (C) used in the present invention is
preferably 2.5 or more and 10.0 or less, and the lower limit is preferably 4.0 or more, and more
preferably 5.0 or more. Specifically, inorganic compound particles selected from the group
consisting of titanium oxide, iron oxide, zinc oxide, zirconium oxide, barium oxide, tin oxide and
ytterbium oxide are preferable, and iron oxide, zinc oxide, zirconium oxide, barium oxide, More
preferred are inorganic compound particles selected from the group consisting of tin oxide and
ytterbium oxide.
[0065]
As the inorganic compound particles (C), only one type may be used alone, or two or more types
may be used in combination.
[0066]
The inorganic compound particles (C) used in the present invention preferably have a specific
surface area of 50 to 400 m <2> / g, and 100 to 400 m <2> / g, from the viewpoint of improving
the hardness and mechanical strength of the obtained silicone resin. Is more preferred.
[0067]
The inorganic compound particle (C) used in the present invention is preferably an inorganic
compound particle whose surface is surface-treated, and more preferably an inorganic compound
particle whose surface is treated with a silane compound.
By treating the surface of the inorganic compound particles with the silane compound, the
interaction with the silicone resin becomes strong, and the affinity with the silicone resin
becomes high, so fine dispersion of inorganic compound particles having a small average
primary particle diameter is possible It is considered to be.
For this reason, it is thought that the inorganic compound particles (C) more function as a
03-05-2019
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stopper when mechanical stress is applied, and the hardness and mechanical strength of the
silicone resin are improved. The surface treatment method may be any conventional method.
Examples of the method of surface treatment with a silane compound include a method of
surface treatment with a silane coupling agent and a method of coating with a silicone
compound.
[0068]
(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 mechanical strength of
the silicone resin. The hydrolyzable group in the silane coupling agent is hydrolyzed by water to
form a hydroxyl group, and the hydroxyl group reacts with the hydroxyl group on the surface of
the inorganic compound particle to cause a surface condensation of the inorganic compound
particle. The hardness and mechanical strength of the silicone resin are improved. Examples of
the hydrolyzable group include an alkoxy group, an acyloxy group, and a halogen atom. When
the surface of the inorganic compound particles is modified to be hydrophobic, the affinity
between the inorganic compound particles (C) and the polyorganosiloxanes (A) and (B) is
improved, and the hardness of the obtained silicone resin is obtained. And mechanical strength is
improved.
[0069]
As a silane coupling agent having a hydrophobic group as a functional group, for example,
methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane,
methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltriol Alkoxysilanes
such as methoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane,
decyltrimethoxysilane; methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane,
chlorosilanes such as phenyltrichlorosilane, hexasilane Methyl disilazane (HMDS) is mentioned.
[0070]
Also, as a silane coupling agent having a vinyl group as a functional group, for example,
methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane,
methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane,
vinyltriethoxy And silanes, vinyltrimethoxysilane, alkoxysilanes such as
vinylmethyldimethoxysilane; vinyltrichlorosilane, chlorosilanes such as
vinylmethyldichlorosilane; and divinyltetramethyldisilazane.
03-05-2019
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[0071]
The inorganic compound particles (C) surface-treated with a silane coupling agent are preferably
inorganic compound particles treated with a trialkylsilylating agent, and more preferably
inorganic compound particles treated with a trimethylsilylating agent.
As a silane compound, the said silane coupling agent and the silane coupling agent by which the
functional group in the silane coupling agent was substituted by the alkyl group are mentioned,
for example.
Further, as the trimethylsilylating agent, for example, trimethylchlorosilane described in the
above-mentioned silane coupling agent, hexamethyldisilazane (HMDS), and
trimethylmethoxysilane which is a silane coupling agent in which a functional group is
substituted by an alkyl group are mentioned. Be
[0072]
Examples of commercially available silane coupling agents include hexamethyldisilazane (HMDS)
(trade name: HEXAMETHYLDISILAZANE (SIH 611 0.1), manufactured by Gelest). The hydroxyl
group present on the inorganic compound particle surface is covered with a trimethylsilyl group
by the reaction with hexamethyldisilazane (HMDS), and the inorganic compound particle surface
is modified to be hydrophobic.
[0073]
(Ii) Silicone Compound The silicone compound covering the inorganic compound particles (C)
may be a polymer composed of siloxane bonds. As the silicone compound, for example, a silicone
compound in which all or a part of the side chain or end of the polysiloxane is a methyl group, a
silicone compound in which a part of the side chain is a hydrogen atom, all or one of a side chain
or an end The modified silicone compound which introduce ¦ transduced organic groups, such as
an amino group and an epoxy group, into the part, The silicone resin which has a branched
structure is mentioned. The silicone compound may have a linear or cyclic structure.
03-05-2019
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[0074]
Examples of silicone compounds in which all or part of the side chains and ends of the
polysiloxane are methyl groups include, for example, polymethylhydrosiloxane (hydrogen end),
polymethylhydrosiloxane (trimethylsiloxy end), polymethylphenylsiloxane ( Hydrogenterminated), monomethylpolysiloxanes such as polymethylphenylsiloxane (trimethylsiloxyterminated), for example dimethylpolysiloxanes (hydrogen-terminated), dimethylpolysiloxanes
(trimethylsiloxy-terminated), dimethylpolysiloxanes such as cyclic dimethylpolysiloxane It can be
mentioned.
[0075]
Examples of silicone compounds in which part of the side chain is a hydrogen atom include
methylhydrosiloxane-dimethylsiloxane copolymer (trimethylsiloxy-terminated),
methylhydrosiloxane-dimethylsiloxane copolymer (hydrogen-terminated),
polymethylhydrosiloxane (hydrogen-terminated) , Polymethylhydrosiloxane (trimethylsiloxyterminated), polyethylhydrosiloxane (triethylsiloxy-terminated), polyphenyl(dimethylhydrosiloxy) siloxane (hydrogen-terminated), methylhydrosiloxanephenylmethylsiloxane copolymer (hydrogen-terminated), methylhydro Siloxane-octylmethyl
siloxane copolymer terpolymers may be mentioned.
[0076]
Moreover, as modified silicone which introduce ¦ transduced the organic group, an amino group,
an epoxy group, a methoxy group, a (meth) acryloyl group, a phenol group, carboxylic acid
anhydride group, a hydroxy group, a mercapto group, a carboxy group, a hydrogen atom is
mentioned, for example. Reactive silicones introduced with organic groups of, for example,
polyether, aralkyl, fluoroalkyl, long chain alkyl, long chain aralkyl, higher fatty acid ester, higher
fatty acid amide, non-reactive silicone modified with polyether methoxy Be
[0077]
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 fixed time and filtering.
03-05-2019
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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 hardness and the machine
of the obtained silicone resin are obtained. Strength is improved.
[0078]
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-terminated).
[0079]
The vinyl group possessed by the polyorganosiloxane (A) and the Si-H group possessed by the
polyorganosiloxane (B) are usually reacted stoichiometrically at 1: 1.
However, in the present invention, since the average primary particle diameter of the inorganic
compound particles (C) is small and the gaps between the polyorganosiloxanes (A) and (B) are
closely packed, the polyorganosiloxanes (A) and The motion of the molecular chain of B) is
restricted.
Therefore, in order for all vinyl groups to react with Si-H groups, the equivalent of Si-H groups in
polyorganosiloxane (B) to vinyl groups in polyorganosiloxane (A) is vinyl group: Si- The H group
is preferably 1: 1.1 to 1: 8, more preferably 1: 1.2 to 1: 5.
[0080]
<Other components> The composition for an acoustic wave probe according to the present
invention comprises a polyorganosiloxane (A) having a vinyl group, a polyorganosiloxane (B)
having two or more Si-H groups in a molecular chain, and an inorganic compound In addition to
particles (C), a platinum catalyst for addition polymerization reaction, a curing retarder, a solvent,
a dispersant, a pigment, a dye, an antistatic agent, an antioxidant, a flame retardant, a thermal
conductivity improver, etc. are appropriately blended. be able to.
[0081]
03-05-2019
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-Catalyst-As a catalyst, for example, platinum or a platinum-containing compound (hereinafter,
also referred to as a platinum compound).
Can be mentioned. Any platinum or platinum compound can be used. Specifically, platinum black,
platinum supported on an inorganic compound or carbon black, etc., chloroplatinic acid or
alcohol solution of chloroplatinic acid, chloroplatinic acid / olefin complex salt, chloroplatinic
acid / vinylsiloxane complex salt Etc. The catalyst may be used alone or in combination of two or
more.
[0082]
The content of the catalyst can be appropriately set in the range of the amount of catalyst. The
catalyst is necessary in the hydrosilylation reaction where the Si-H group of polyorganosiloxane
(B) is added to the vinyl group of polyorganosiloxane (A). By the addition curing reaction by
hydrosilylation, the polyorganosiloxane (A) is crosslinked by the polyorganosiloxane (B) to form a
silicone resin. Here, the catalyst may be contained in the acoustic wave probe composition of the
present invention, or may be brought into contact with the acoustic wave probe composition
without being contained in the acoustic wave probe composition. The latter is preferred.
[0083]
Examples of commercially available platinum catalysts include platinum compounds (trade name:
PLATINUM CYCLOVINYLMETHYLSILOXANE COMPLEX IN CYCLIC METHYL VINYLSILOX ANES
(SIP 6832.2), Pt concentration 2% by mass, manufactured by Gelest).
[0084]
When the catalyst is contained in the composition for acoustic wave probes of the present
invention, the content of the catalyst is preferably 0.00001 to 0.05 parts by mass with respect to
100 parts by mass of the polysiloxane mixture from the viewpoint of reactivity. 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.
[0085]
03-05-2019
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In addition, the curing temperature can be adjusted by selecting an appropriate platinum
catalyst.
For example, platinum-vinyldisiloxane is used for room temperature cure (RTV) below 50 ° C
and platinum-cyclic vinylsiloxane is used for high temperature cure (HTV) above 130 ° C.
[0086]
-Curing Retarder-In the present invention, a curing retarder for the curing reaction can be
suitably used.
The curing retarder is used for the purpose of delaying a platinum-catalyzed addition curing
reaction, and examples thereof include low molecular weight vinylmethylsiloxane homopolymer
(trade name: VMS-005, manufactured by Gelest). The curing rate, ie, the working time can be
adjusted by the content of the curing retarder.
[0087]
<A Composition for an Acoustic Wave Probe and a Method of Producing a Silicone Resin for an
Acoustic Wave Probe> The composition for an acoustic wave probe of the present invention can
be prepared by any method. For example, the component which comprises the composition for
acoustic wave probes can be obtained by knead ¦ mixing with the kneader, a pressure kneader, a
Banbury mixer (continuous kneader), and the kneading ¦ mixing apparatus of 2 rolls. The order
of mixing of the components is not particularly limited. From the viewpoint of obtaining a
uniform composition, inorganic compound particles are first added to a polyorganosiloxane (A)
having a vinyl group and a polyorganosiloxane (B) having two or more Si-H groups in a
molecular chain. It is preferable to make it a polyorganosiloxane mixture in which (C) is
dispersed. Thereafter, a catalyst is added to the polyorganosiloxane mixture in which the
inorganic compound particles (C) are dispersed, and degassing under reduced pressure, whereby
a composition for an acoustic wave probe can be produced.
[0088]
03-05-2019
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By curing the composition for acoustic wave probe of the present invention thus obtained, the
silicone resin for acoustic wave probe of the present invention can be obtained. Specifically, for
example, a silicone resin for an acoustic wave probe can be obtained by heat curing at 20 to 200
° C. for 5 to 500 minutes.
[0089]
<Mechanical Strength and Acoustic Wave Properties of Silicone Resin> The silicone resin for an
acoustic wave probe of the present invention is a cured product of the composition for an
acoustic wave probe of the present invention. The mechanical strength and acoustic wave
properties of the silicone resin are described in detail below. Here, the acoustic wave
characteristics will be described for ultrasonic characteristics. However, the acoustic wave
characteristic is not limited to the ultrasonic wave characteristic, and relates to an acoustic wave
characteristic of an appropriate frequency which is selected according to an object to be
examined, a measurement condition, and the like.
[0090]
[Hardness] With respect to a silicone resin sheet having a thickness of 2 mm, in accordance with
JIS K6253-3 (2012), the type A durometer hardness is measured using a rubber hardness tester
(for example, a trade name "RH-201A" manufactured by Excell Co.) . The hardness is preferably
15 or more, and more preferably 25 or more from the viewpoint of preventing deformation when
incorporated as a part of the acoustic wave probe. Note that the practical upper limit is 80 or
less.
[0091]
[Tensile Test] A dumbbell-shaped test piece is prepared from a silicone resin sheet having a
thickness of 1 mm in accordance with JIS K6251 (2010), and the tensile breaking strength and
the tensile breaking elongation (elongation) are measured. The tensile breaking strength is
preferably 1.2 MPa or more, and the tensile breaking elongation is preferably 500% or more. In
addition, a realistic upper limit is 10 MPa or less in tensile strength at break, and 1500% or less
in tensile strength at break.
03-05-2019
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[0092]
[Tear Strength Test] A 2 mm-thick silicone resin sheet was prepared in accordance with JIS
K6252 (2007) to prepare a trouser-type test piece, and the tear strength was measured. The tear
strength is preferably 15 N / cm or more, more preferably 20 N / cm or more, and still more
preferably 30 N / cm or more. In addition, a realistic upper limit is 100 N / cm or less.
[0093]
[Abrasion resistance test] With respect to a silicone resin sheet having a thickness of 2 mm, a
Taber abrasion test is carried out in accordance with JIS K 6264-2 (2005) to measure a mass
loss. The grinding wheel is measured at H22, the load is 9.8 N, and the test rotational speed is
1000 revolutions. A mass loss of less than 30 mg is "A", 30 mg or more and less than 50 mg is
"B", 50 mg or more and less than 70 mg is "C", and more than 70 mg is "D". Here, evaluation "A"
and "B" show that it is considerably excellent in abrasion resistance, "C" shows that it can be
used, and "D" shows that it can not be used.
[0094]
[Acoustic impedance] With respect to a silicone resin sheet having a thickness of 2 mm, an
electronic hydrometer (for example, Alpha Mirage Co., Ltd.) according to the density
measurement method of Method A (substitution method in water) described in JIS K7112
(1999). Manufactured using "SD-200L"). The sound velocity of the acoustic wave is measured at
25 ° C. according to JIS Z 2353 (2003) using a single-around sound velocity measuring
apparatus (for example, UVM-2 type manufactured by Ultrasonic Industry Co., Ltd.), and the
measured density Determine the acoustic impedance from the product of the speed of sound.
[0095]
[Acoustic wave (ultrasonic wave) attenuation, sensitivity] 5 MHz sine wave signal (one wave)
output from an ultrasonic oscillator (for example, function generator, product name "FG-350"
manufactured by Iwatsu Measurement Co., Ltd.) Is input to an ultrasonic probe (for example,
manufactured by Japan Probe Co., Ltd.), and an ultrasonic pulse wave having a center frequency
of 5 MHz is generated in water from the ultrasonic probe. The amplitude of the generated
03-05-2019
27
ultrasonic waves before and after passing through a 2 mm thick silicone resin sheet was
measured by an ultrasonic receiver (for example, an oscilloscope manufactured by Matsushita
Electric Industrial Co., Ltd., trade name "VP-5204A"). Measure the acoustic wave (ultrasonic)
attenuation of each sheet by measuring in an environment of water temperature 25 ° C. and
comparing the acoustic wave (ultrasonic) sensitivity. The acoustic wave (ultrasound) sensitivity is
a numerical value given by the following formula. In the following formula, Vin represents a
voltage peak value of an input wave having a half width of 50 nsec or less by the ultrasonic
oscillator. Vs represents a voltage value obtained when the generated acoustic wave (ultrasonic
wave) passes through the sheet and the ultrasonic wave receives the acoustic wave (ultrasound)
reflected from the opposite side of the sheet.
[0096]
Acoustic wave (ultrasonic) sensitivity = 20 x Log (Vs / Vin)
[0097]
In the evaluation system of the present invention, the acoustic wave (ultrasound) sensitivity is
preferably -72 dB or more, and more preferably -71 dB or more.
[0098]
The composition for an acoustic wave probe of the present invention is useful for a medical
member, and can be preferably used, for example, in an acoustic wave probe or an acoustic wave
measurement device.
The acoustic wave measuring apparatus according to the present invention is not limited to an
ultrasonic diagnostic apparatus or a photoacoustic wave measuring apparatus, and refers to an
apparatus that receives an acoustic wave reflected or generated by an object and displays it as an
image or a signal intensity.
In particular, the composition for acoustic wave probe according to the present invention is
provided between the acoustic lens of the ultrasonic diagnostic apparatus or between the
piezoelectric element and the acoustic lens to have the role of matching the acoustic impedance
between the piezoelectric element and the acoustic lens. Acoustic matching layer material,
photoacoustic wave measuring device and acoustic lens material in ultrasound endoscope and
acoustic probe in ultrasound probe with Capacitive Micromachined Ultrasonic Transducers
03-05-2019
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(cMUT) as ultrasound transducer array It can be suitably used as a material of a lens or the like.
Specifically, the silicone resin for an acoustic wave probe of the present invention may be, for
example, an ultrasonic diagnostic apparatus described in JP-A-2005-253751, JP-A-2003169802, or the like, JP-A-2013-202050 , Preferably applied to an acoustic wave measuring
apparatus such as a photoacoustic wave measuring apparatus described in Japanese Patent
Application Laid-Open Nos. 2013-188465, 2013-180330, 2013-158435, 2013-154139 etc. Be
done.
[0099]
<< Acoustic Wave Probe (Probe) >> The structure of the acoustic wave probe of the present
invention will be described in more detail below based on the structure of the ultrasonic probe in
the ultrasonic diagnostic apparatus described 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 ultrasound probe can be applied to the acoustic wave probe
as it is.
[0100]
-Ultrasonic probe-The ultrasonic probe 10 is a main component of an ultrasonic diagnostic
apparatus, and has a function of generating an ultrasonic wave and transmitting and receiving an
ultrasonic beam. The configuration of the ultrasonic probe 10 is, as shown in FIG. 1, 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 in contact with a living body being a subject)
There is. In recent years, in order to receive high-order harmonics, a transmitting ultrasonic
transducer (piezoelectric element) and a receiving ultrasonic transducer (piezoelectric element)
are made of different materials and have a laminated structure. Is also proposed.
[0101]
<Piezoelectric Element Layer> The piezoelectric element layer 3 is a portion that generates
ultrasonic waves, and electrodes are attached to both sides of the piezoelectric element, and
when voltage is applied, the piezoelectric element repeatedly vibrates expansion and contraction.
, Ultrasonic waves are generated.
[0102]
03-05-2019
29
As materials for constituting the piezoelectric element, quartz, single crystals such as LiNbO 3,
LiTaO 3, and KNbO 3, thin films such as ZnO and AlN, and sintered bodies such as Pb (Zr, Ti) O 3
series are subjected to polarization processing. So-called ceramic inorganic piezoelectric
materials are widely used.
In general, piezoelectric ceramics such as PZT: lead zirconate titanate having high conversion
efficiency are used. In addition, the piezoelectric element that detects the received wave on the
high frequency side needs sensitivity with a wider bandwidth. For this reason, an organic
piezoelectric material using an organic polymer substance such as polyvinylidene fluoride (PVDF)
is used as a piezoelectric element suitable for high frequency and wide band. Furthermore,
Japanese Patent Application Laid-Open No. 2011-071842 or the like uses MEMS (Micro Electro
Mechanical Systems) technology that exhibits excellent short pulse characteristics and wide band
characteristics, is excellent in mass productivity, and provides an array structure with less
characteristic variation. cMUT is described. In the present invention, any piezoelectric element
material can be preferably used.
[0103]
<Backing Material> The backing material 4 is provided on the back surface of the piezoelectric
element layer 3 and suppresses the extra vibration to shorten the pulse width of the ultrasonic
wave, thereby contributing to the improvement of the distance resolution in the ultrasonic
diagnostic image. .
[0104]
<Acoustic Matching Layer> The acoustic matching layer 2 is provided to reduce the difference in
acoustic impedance between the piezoelectric element layer 3 and the subject and efficiently
transmit and receive ultrasonic waves.
The composition for an ultrasonic probe according to the present invention has a small
difference from the acoustic impedance (1.4 to 1.7 × 10 6 <6> kg / m 2> / sec) of a living body,
and thus the material of the acoustic matching layer It can be preferably used as The acoustic
matching layer of the present invention preferably contains 10% by mass or more of a silicone
resin for an acoustic wave probe obtained by curing reaction of the composition for an acoustic
wave probe of the present invention.
03-05-2019
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[0105]
<Acoustic Lens> The acoustic lens 1 is provided for focusing ultrasonic waves in the slice
direction using refraction to improve resolution. And intimately contacting with the living body
which is the subject, and matching the ultrasonic wave with the acoustic impedance of the living
body (in the human body, 1.4 to 1.7 × 10 6 <6> kg / m 2> / sec); It is required that the
ultrasonic attenuation amount of the acoustic lens 1 itself is small. That is, as the material of the
acoustic lens 1, ultrasonic waves are transmitted / received by using a material whose sound
velocity is sufficiently smaller than the sound velocity of the human body and attenuation of
ultrasonic waves is small, and whose acoustic impedance is close to the value of human skin. The
sensitivity is improved. The composition for acoustic wave probes which is a composition for
ultrasonic probes of the present invention can be preferably used also as an acoustic lens
material.
[0106]
The operation of the ultrasonic probe 10 having such a configuration will be described. A voltage
is applied to electrodes provided on both sides of the piezoelectric element to cause the
piezoelectric element layer 3 to resonate, and an ultrasonic signal is transmitted from the
acoustic lens to the subject. At the time of reception, the piezoelectric element layer 3 is vibrated
by a reflection signal (echo signal) from the subject, and the vibration is electrically converted
into a signal to obtain an image.
[0107]
In particular, an acoustic lens obtained from the composition for an ultrasonic probe of the
present invention can confirm a remarkable sensitivity improvement effect at a transmission
frequency of ultrasonic waves of about 5 MHz or more as a general medical ultrasonic
transducer. In particular, at the transmission frequency of ultrasonic waves of 10 MHz or more, a
particularly remarkable sensitivity improvement effect can be expected. Hereinafter, an
apparatus in which an acoustic lens obtained from the composition for an ultrasonic probe of the
present invention exerts a function particularly against the conventional problems will be
described in detail. In addition, the composition for ultrasonic probes of this invention shows the
outstanding effect also to apparatuses other than describing below.
03-05-2019
31
[0108]
-Ultrasonic probe provided with cMUT (capacitive micromachine ultrasonic transducer)-When
using the cMUT device described in JP 2006-157320 A, JP 2011-71842 A etc. for a transducer
array for ultrasonic diagnosis, in general In general, its sensitivity is lower than that of a
piezoelectric ceramic (PZT) based transducer. However, by using an acoustic lens obtained from
the composition for an acoustic wave probe of the present invention, it is possible to compensate
for the lack of sensitivity of the cMUT. This allows the sensitivity of the cMUT to be close to the
performance of a conventional transducer. In addition, since the cMUT device is manufactured by
the MEMS technology, it is possible to provide a low-cost ultrasonic probe with higher mass
productivity and lower cost than the piezoelectric ceramic probe.
[0109]
-Photoacoustic wave measuring device by optical ultrasonic imaging-Photoacoustic imaging (PAI:
Photo Acoustic Imaging) described in Japanese Patent Application Laid-Open No. 2013-158435
and the like irradiates light (electromagnetic wave) to the inside of a human body and the
irradiated light The ultrasound image generated when the human body tissue adiabatically
expands is displayed or the signal intensity of the ultrasound is displayed. 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 composition for an acoustic wave probe of the present invention, it is possible
to exhibit an effective effect on this problem.
[0110]
-Ultrasonic endoscope-The ultrasonic wave in the ultrasonic endoscope described in Japanese
Patent Application Laid-Open No. 2008-311700, etc., has a long signal line cable compared to
the body surface transducer due to its structure, so cable loss The problem is to improve the
sensitivity of the transducer. Moreover, it is said that there is no effective sensitivity
improvement means to this subject by the following reasons.
[0111]
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First, in the case of an ultrasonic diagnostic apparatus for body surface, an amplifier circuit, an
AD conversion IC, etc. can be installed at the tip of the transducer. On the other hand, since the
ultrasonic endoscope is inserted into the body and used, the installation space of the transducer
is narrow, and it is difficult to install an amplifier circuit, an AD conversion IC, etc. on the tip of
the transducer. Second, the piezoelectric single crystal employed in the transducer in the
ultrasonic diagnostic apparatus for body surface is difficult to apply to a transducer with an
ultrasound transmission frequency of 7-8 MHz or more, due to its physical characteristics and
process suitability. . However, since ultrasound for endoscopes is generally a probe with a
transmission frequency of 7 to 8 MHz or more of ultrasound, it is also difficult to improve
sensitivity by a piezoelectric single crystal material.
[0112]
However, by using an acoustic lens obtained from the composition for an acoustic wave probe of
the present invention, it is possible to improve the sensitivity of an endoscopic ultrasonic
transducer. In addition, even when using the same ultrasonic transmission frequency (for
example, 10 MHz), the effectiveness is particularly effective when using an acoustic lens obtained
from the composition for an acoustic wave probe of the present invention in an ultrasonic
transducer for endoscopes. It is exhibited.
[0113]
Hereinafter, the present invention will be described in more detail based on an embodiment
using an ultrasonic wave as an acoustic wave. Note that the present invention is not limited to
ultrasonic waves, and audio waves of audible frequencies may be used as long as appropriate
frequencies are selected according to an object to be detected, measurement conditions, and the
like.
[0114]
[Example 1] 68 parts by mass of vinyl-terminated polydimethylsiloxane (manufactured by Gelest,
trade name "DMS-V42", weight average molecular weight 72,000), methylhydrosiloxanedimethylsiloxane copolymer (manufactured by Gelest, trade name "HMS" -301 ", mass average
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molecular weight 2,000, methyl hydrosiloxane ratio 27 mol% 2 parts by mass, magnesium oxide
(specific gravity 3.6, average primary particle diameter 19 nm, hexamethyldisilazane (HMDS)
surface treatment) 30 parts by mass It knead ¦ mixed for 2 hours with a kneader, and was set as
the uniform paste. To this, 0.05 parts by mass of a platinum catalyst solution (Gelest, trade name
"SIP 6832.2", Pt concentration 2% by mass) is added and mixed, followed by vacuum degassing,
and put in a 150 mm x 150 mm metal mold Heat treatment was carried out at 60 ° C. for 3
hours to obtain silicone resin sheets having a thickness of 1 mm and 2 mm, respectively.
[0115]
[Example 2] The same treatment as in Example 1 was carried out except that titanium oxide
(specific gravity 4.2, average primary particle diameter 14 nm, surface treatment with
hexamethyldisilazane (HMDS)) of 30 parts by mass was used as inorganic compound particles. ,
A predetermined silicone resin sheet was obtained.
[0116]
Example 3 The same treatment as in Example 1 was carried out except that 30 parts by mass of
iron oxide (specific gravity 5.2, average primary particle diameter 21 nm, surface treatment of
hexamethyldisilazane (HMDS)) was used as the inorganic compound particles. , A predetermined
silicone resin sheet was obtained.
[0117]
[Example 4] 68 parts by mass of vinyl-terminated polydimethylsiloxane (manufactured by Gelest,
trade name "DMS-V42", weight average molecular weight 72,000), methylhydrosiloxanedimethylsiloxane copolymer (manufactured by Gelest, trade name "HMS" -301 ", mass average
molecular weight 2,000, 2 parts by mass of methylhydrosiloxane ratio 27 mol%, zinc oxide
(specific gravity 5.6, average primary particle diameter 11 nm, hexamethyldisilazane (HMDS)
surface treatment) 30 parts by mass They were mixed in the same manner as in Example 1 and
thermally cured with a platinum catalyst in the same manner as in Example 1 to obtain a
predetermined silicone resin sheet.
[0118]
Example 5 The same treatment as in Example 1 was carried out except that 30 parts by mass of
zirconium oxide (specific gravity 5.9, average primary particle diameter 11 nm,
hexamethyldisilazane (HMDS) surface treatment) was used as inorganic compound particles. , A
predetermined silicone resin sheet was obtained.
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[0119]
Example 6 The same treatment as in Example 1 was carried out except that barium oxide
(specific gravity 6.7, average primary particle diameter 24 nm, hexamethyldisilazane (HMDS)
surface treatment) was used as the inorganic compound particles in an amount of 30 parts by
mass. , A predetermined silicone resin sheet was obtained.
[0120]
Example 7 The same treatment as in Example 1 was carried out except that 30 parts by mass of
tin oxide (specific gravity 7.0, average primary particle diameter 22 nm, hexamethyldisilazane
(HMDS) surface treatment) was used as inorganic compound particles. , A predetermined silicone
resin sheet was obtained.
[0121]
Example 8 The same treatment as in Example 1 was carried out except that 30 parts by mass of
ytterbium oxide (specific gravity 9.2, average primary particle diameter 20 nm,
hexamethyldisilazane (HMDS) surface treatment) was used as inorganic compound particles. , A
predetermined silicone resin sheet was obtained.
[0122]
Example 9 A silicone resin sheet was treated in the same manner as in Example 4 except that 30
parts by mass of zinc oxide (specific gravity 5.6, average primary particle diameter 11 nm, no
surface treatment) was used as inorganic compound particles. I got
[0123]
[Example 10] As a polyorganosiloxane having a vinyl group, a vinyl-terminated
polydimethylsiloxane (manufactured by Gelest, trade name "DMS-V31", mass average molecular
weight 28,000) 65 parts by mass, a polyorgano having a Si-H group The same as Example 4
except that 5 parts by mass of methylhydrosiloxane-dimethylsiloxane copolymer (manufactured
by Gelest, trade name "HMS-301", weight average molecular weight 2,000, methylhydrosiloxane
ratio 27 mol%) was used as siloxane. To obtain a predetermined silicone resin sheet.
[0124]
Example 11 A vinyl-terminated polydimethylsiloxane (manufactured by Gelest, trade name
DMS-V35 , mass average molecular weight 49, 500) as a polyorganosiloxane having a vinyl
group, 67 parts by mass, a polyorgano having a Si̶H group Example 6 is the same as Example 4
except that 3 parts by mass of methylhydrosiloxane-dimethylsiloxane copolymer (manufactured
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by Gelest, trade name "HMS-301", weight average molecular weight 2,000, methylhydrosiloxane
ratio 27 mol%) is used as the siloxane. To obtain a predetermined silicone resin sheet.
[0125]
Example 12 A vinyl-terminated polydimethylsiloxane (Gelest, trade name DMS-V46 , mass
average molecular weight 117,000) 69 parts by mass as a polyorganosiloxane having a vinyl
group, a polyorgano having a Si̶H group The same as Example 4 except that 1 part by mass of
methylhydrosiloxane-dimethylsiloxane copolymer (manufactured by Gelest, trade name "HMS301", weight average molecular weight 2,000, methylhydrosiloxane ratio 27 mol%) was used as
siloxane. To obtain a predetermined silicone resin sheet.
[0126]
[Example 13] A vinyl-terminated polydimethylsiloxane (Gelest, trade name "DMS-V52", mass
average molecular weight 155,000) 69 parts by mass as a polyorganosiloxane having a vinyl
group, a polyorgano having a Si-H group The same as Example 4 except that 1 part by mass of
methylhydrosiloxane-dimethylsiloxane copolymer (manufactured by Gelest, trade name "HMS301", weight average molecular weight 2,000, methylhydrosiloxane ratio 27 mol%) was used as
siloxane. To obtain a predetermined silicone resin sheet.
[0127]
[Example 14] As a polyorganosiloxane having a vinyl group, a vinyl-terminated
polydimethylsiloxane (manufactured by Gelest, trade name "DMS-V42", mass average molecular
weight 72,000) 78 parts by mass, a polyorgano having a Si-H group 2 parts by mass of
methylhydrosiloxane-dimethylsiloxane copolymer (manufactured by Gelest, trade name HMS301 , weight average molecular weight 2,000, methylhydrosiloxane ratio 27 mol%) as siloxane,
zinc oxide (specific gravity 5.0) as inorganic compound particles. 6. A predetermined silicone
resin sheet was obtained in the same manner as in Example 4 except that 20 parts by mass of an
average primary particle diameter of 11 nm and hexamethyldisilazane (HMDS) surface
treatment) was used.
[0128]
[Example 15] As a polyorganosiloxane having a vinyl group, a vinyl-terminated
polydimethylsiloxane (manufactured by Gelest, trade name "DMS-V42", mass average molecular
weight 72,000) 59 parts by mass, a polyorgano having a Si-H group 1 part by mass of
methylhydrosiloxane-dimethylsiloxane copolymer (manufactured by Gelest, trade name "HMS301", weight average molecular weight 2,000, methylhydrosiloxane ratio 27 mol%) as siloxane,
zinc oxide (specific gravity 5.0) as inorganic compound particles. 6. A predetermined silicone
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resin sheet was obtained in the same manner as in Example 4 except that 40 parts by mass of
average primary particle diameter 11 nm and hexamethyldisilazane (HMDS) surface treatment
were used. .
[0129]
[Example 16] A vinyl-terminated diphenylsiloxane-dimethylsiloxane copolymer (Gelest, trade
name "PDV-0535", weight average molecular weight 47,500, amount of diphenylsiloxane 5%) as
a polyorganosiloxane having a vinyl group, 68 parts by mass It processed like Example 8 except
having used, and obtained the predetermined ¦ prescribed silicone resin sheet.
[0130]
Example 17 A vinyl-terminated diphenylsiloxane-dimethylsiloxane copolymer (Gelest, trade name
"PDV-1635", weight average molecular weight 35, 300, diphenylsiloxane content 16 mol%) 68
weight parts as polyorganosiloxane having vinyl group It processed similarly to Example 8
except having used, and obtained the predetermined ¦ prescribed silicone resin sheet.
[0131]
Comparative Example 1 The same treatment as in Example 1 was conducted except that 30 parts
by mass of magnesium oxide (specific gravity: 3.6, average primary particle diameter: 60 nm,
hexamethyldisilazane (HMDS) surface treatment) was used as the inorganic compound particles. ,
A predetermined silicone resin sheet was obtained.
[0132]
Comparative Example 2 The same treatment as in Example 1 was carried out except that 30
parts by mass of titanium oxide (specific gravity 4.2, average primary particle diameter 28 nm,
surface treatment of hexamethyldisilazane (HMDS)) was used as inorganic compound particles. ,
A predetermined silicone resin sheet was obtained.
[0133]
Comparative Example 3 The same treatment as in Example 1 was conducted except that 30 parts
by mass of iron oxide (specific gravity 5.2, average primary particle diameter 42 nm,
hexamethyldisilazane (HMDS) surface treatment) was used as the inorganic compound particles. ,
A predetermined silicone resin sheet was obtained.
[0134]
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Comparative Example 4 The same treatment as in Example 1 was carried out except that 30
parts by mass of zinc oxide (specific gravity 5.6, average primary particle diameter 30 nm,
surface treatment of hexamethyldisilazane (HMDS)) was used as inorganic compound particles. ,
A predetermined silicone resin sheet was obtained.
[0135]
Comparative Example 5 The same treatment as in Example 1 was carried out except that 30
parts by mass of zirconium oxide (specific gravity 5.9, average primary particle diameter 31 nm,
hexamethyldisilazane (HMDS) surface treatment) was used as inorganic compound particles. , A
predetermined silicone resin sheet was obtained.
[0136]
Comparative Example 6 The same treatment as in Example 1 was carried out except that barium
oxide (specific gravity 6.7, average primary particle diameter 52 nm, hexamethyldisilazane
(HMDS) surface treatment) was used as the inorganic compound particles in an amount of 30
parts by mass. , A predetermined silicone resin sheet was obtained.
[0137]
Comparative Example 7 The same treatment as in Example 1 was carried out except that 30
parts by mass of tin oxide (specific gravity 7.0, average primary particle diameter 75 nm, surface
treatment of hexamethyldisilazane (HMDS)) was used as the inorganic compound particles. , A
predetermined silicone resin sheet was obtained.
[0138]
Comparative Example 8 The same treatment as in Example 1 was carried out except that 30
parts by mass of ytterbium oxide (specific gravity 9.2, average primary particle diameter 25 nm,
surface treatment of hexamethyldisilazane (HMDS)) was used as inorganic compound particles. ,
A predetermined silicone resin sheet was obtained.
[0139]
Comparative Example 9 98 parts by mass of vinyl-terminated polydimethylsiloxane
(manufactured by Gelest, trade name "DMS-V42", weight average molecular weight 72,000),
methylhydrosiloxane-dimethylsiloxane copolymer (manufactured by Gelest, trade name "HMS" In
the same manner as in Example 1, 2 parts by mass of −301 , mass average molecular weight
2,000, methyl hydrosiloxane ratio 27 mol%) are mixed and thermally cured with a platinum
catalyst in the same manner as in Example 1. A silicone resin sheet was obtained.
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[0140]
<Evaluation of mechanical strength and ultrasonic characteristics> The following evaluations
were performed on the silicone resin sheets of Examples 1 to 17 and Comparative Examples 1 to
9.
[0141]
[Hardness] The obtained silicone resin sheet having a thickness of 2 mm was measured using a
rubber hardness tester (trade name RH-201A manufactured by Excell Co., Ltd.) according to
JIS K6253-3 (2012) and using a rubber hardness tester (trade name RH-201A ). did.
[0142]
[Tensile Test] Dumbbell-shaped test pieces were produced from the obtained silicone resin sheet
having a thickness of 1 mm in accordance with JIS K6251 (2010), and the tensile breaking
strength and the tensile breaking elongation were measured.
[0143]
[Tear strength test] With respect to the obtained silicone resin sheet having a thickness of 2 mm,
a trousers type test piece was produced according to JIS K6252 (2007), and tear strength was
measured.
[0144]
[Abrasion resistance test] The obtained silicone resin sheet with a thickness of 2 mm was
subjected to a Taber abrasion test in accordance with JIS K 6264-2 (2005), and the amount of
mass loss was measured.
In addition, the grinding wheel was measured on the conditions of H22, load 9.8N, and test
rotational speed 1000 rotation conditions.
Less than 30 mg was designated as "A", 30 mg or more and less than 50 mg as "B", 50 mg or
more and less than 70 mg as "C", and those exceeding 70 mg as "D".
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Here, evaluation "A" and "B" show that it is considerably excellent in abrasion resistance, "C"
shows that it can be used, and "D" shows that it can not be used.
[0145]
[Acoustic Impedance] The obtained silicone resin sheet having a thickness of 2 mm was
subjected to an electron densitometer (alpha mirage) according to the density measurement
method of Method A (substitution method in water) described in JIS K7112 (1999). It measured
using company make and brand name "SD-200L").
Ultrasonic speed of sound is measured at 25 ° C. according to JIS Z 2353 (2003) using a singlearound sound speed measuring device (manufactured by Ultrasonic Industry Co., Ltd., trade
name UVM-2 type ), and the measured density and speed of sound The acoustic impedance
was determined from the product of
[0146]
[Acoustic wave (ultrasonic wave) sensitivity] Ultrasonic probe (one wave) of a 5 MHz sine wave
signal (one wave) output from an ultrasonic oscillator (function generator, product name: "FG350" manufactured by Iwatsu Measurement Co., Ltd.) An ultrasonic pulse wave having a center
frequency of 5 MHz was generated in water from an ultrasonic probe.
The amplitude of the generated ultrasonic waves before and after passing through the obtained 2
mm thick silicone resin sheet was measured using an ultrasonic wave receiver (manufactured by
Matsushita Electric Industrial Co., Ltd., an oscilloscope, trade name "VP-5204A"). Thus, the
measurement was made in an environment of water temperature 25 ° C., and the acoustic wave
(ultrasonic wave) attenuation was compared by comparing the acoustic wave (ultrasonic wave)
sensitivity.
The acoustic wave (ultrasound) sensitivity is a numerical value given by the following formula.
In the following formula, Vin represents a voltage peak value of an input wave having a half
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width of 50 nsec or less by the ultrasonic oscillator.
Vs represents a voltage value obtained when the generated acoustic wave (ultrasonic wave)
passes through the sheet and the ultrasonic wave receives the acoustic wave (ultrasound)
reflected from the opposite side of the sheet.
[0147]
Acoustic wave (ultrasonic) sensitivity = 20 x Log (Vs / Vin)
[0148]
The obtained results are summarized and shown in Tables 1 to 3 below.
In Tables 1 to 3 below, mass average molecular weights of the polyorganosiloxanes (A) and (B)
are simply described as molecular weights, and the type of each component is a trade name.
[0149]
[0150]
[0151]
[0152]
As shown in Tables 1 to 3, the silicone resins for acoustic wave probes of Examples 1 to 17 all
have high resin hardness, tensile breaking strength, and tension while maintaining acoustic wave
(ultrasonic wave) sensitivity of -72 dB or more. Elongation at break and tear strength and
excellent wear resistance could be obtained.
On the other hand, in all of the silicone resins for acoustic wave probe of Comparative Examples
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1 to 9, sufficient tensile elongation at break and tear strength were not obtained.
[0153]
From this result, it is understood that the composition for acoustic wave probe of the present
invention is useful for a medical member.
The silicone resin of the present invention can also be suitably used for an acoustic lens and / or
an acoustic matching layer of an acoustic wave probe, and an acoustic wave measurement device
and an ultrasonic diagnostic device.
In particular, the composition for an acoustic wave probe and the silicone resin for an acoustic
wave probe are used for the purpose of improving sensitivity in an ultrasonic probe, a
photoacoustic wave measuring apparatus and an ultrasonic endoscope using cMUT as a
transducer array for ultrasonic diagnosis. It can be used suitably.
[0154]
While the present invention has been described in conjunction with its embodiments, we do not
intend to limit our invention in any detail of the description unless otherwise specified, which is
contrary to the spirit and scope of the invention as set forth in the appended claims. I think that
it should be interpreted broadly without.
[0155]
The present application claims priority based on Japanese Patent Application No. 2014-243074
filed in Japan on December 1, 2014, and Japanese Patent Application No. 2015-218499 filed in
Japan on November 6, 2015. Each of which is incorporated herein by reference in its entirety as
part of the present description.
[0156]
1 acoustic lens 2 acoustic matching layer 3 piezoelectric element layer 4 backing material 7
housing 9 code 10 ultrasonic probe (probe)
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