JP6358795B2 - Composite plate and manufacturing method thereof - Google Patents

Description

  The present invention relates to a composite plate and a manufacturing method thereof, and in particular, a composite suitable as a heat radiating member for radiating heat from an acoustic matching layer or an electronic component that suppresses reflection of waves from a vibrator and passes to a measurement target layer in an ultrasonic diagnostic apparatus It is related with a board and its manufacturing method.

  In the ultrasonic diagnostic apparatus, the acoustic impedance of PZT used as a vibrator is about 35 Mrayl (megarail), whereas the acoustic impedance of a human body to be measured is significantly different from 1 to 2 Mrayl. Therefore, it is necessary to efficiently transmit ultrasonic waves through a matching layer having an intermediate acoustic impedance value between the transducer and the measurement target.

  Patent Document 1 below describes that polymethylpentene having an acoustic impedance of about 1.7 to 1.8 is used as the matching layer.

  Patent Document 2 discloses that light particles having a density of 4.0 g / cc or less and heavy particles having a density of more than 4.0 g / cc are dispersed in a matrix of epoxy resin to 3.0 megarail to about 7 Obtaining a matching layer 108 having an acoustic impedance between 0.0 megarail and dispersing micron-sized and nano-sized particles in an epoxy resin matrix from about 7.0 megarail to about 14.0; It is described to obtain a matching layer 110 having an acoustic impedance between megarails.

JP 2013-34138 A JP2013-81241A

  An object of the present invention is to provide a novel composite plate suitable for use as an acoustic matching layer in an ultrasonic diagnostic apparatus and a method for manufacturing the same.

  A second object of the present invention is to provide a composite plate suitable for use as a heat dissipation member for heat dissipation of electronic components and a method for manufacturing the same.

  According to the present invention, there is provided a composite plate comprising a plate-like base material and crystalline carbon powder dispersed in the base material and oriented in a direction perpendicular to the plate surface.

  The base material includes amorphous carbon.

  Alternatively, the base material includes a cured resin.

  It is preferable that the crystalline carbon powder is uniformly dispersed in the base material.

  The above-described composite plate is obtained by uniformly dispersing crystalline carbon powder in a resin, forming the resin in which the crystalline carbon powder is uniformly dispersed into a rod shape by an extruder, and curing the resin by heating the molded product. The molded product is cut into a required length before or after the resin is cured to produce a plate having a required thickness.

  Preferably, the resin is a carbon-containing resin, and further includes baking and carbonizing the molded product obtained by curing the resin in a non-oxidizing atmosphere before or after the cutting.

  The above-mentioned composite plate is obtained by uniformly dispersing crystalline carbon powder in a resin, applying a magnetic field in the thickness direction in the mold to the resin in which the crystalline carbon powder is uniformly dispersed, and curing the resin to which the magnetic field is applied. It is manufactured also by the method containing.

  The resin is a carbon-containing resin, and preferably further includes baking and carbonizing the resin in a non-oxidizing atmosphere after the curing.

  The above-mentioned composite plate is a bundle of a plurality of shaft members each including a rod-shaped base material of amorphous carbon or a cured resin and crystalline carbon powder that is oriented in the axial direction of the base material and is uniformly dispersed in the base material. It is also manufactured by a method including injecting a resin into the gap between the bundled shaft members, bonding the shaft members to each other, and curing the resin injected into the gap.

  The shaft material includes a shaft material, a pencil core, or a sharp core, in which crystalline carbon powder is uniformly dispersed in a resin, formed into a rod shape with an extruder and fired in a non-oxidizing atmosphere. The pencil lead or sharp lead is obtained by mixing graphite with resin and dispersing it uniformly, forming it into a fine line with an extruder, and then heat treating it to carbonize the resin.

  The shafts are preferably arranged in close-packed manner, but may be spaced at regular intervals.

  The aforementioned crystalline carbon powder is, for example, graphite particles and / or carbon fibers.

2 is a photomicrograph of a cross section in the thickness direction of the composite plate obtained in Example 1. FIG. 2 is a micrograph of a cross section in the plate surface direction of the composite plate obtained in Example 1. FIG. It is a microscope picture of the cross section of the thickness direction of the composite board obtained in the comparative example 2 which does not apply a magnetic field to the thickness direction. It is a microscope picture of the cross section of the thickness direction of the composite board obtained in Example 2 in which a magnetic field is applied to the thickness direction. It is a photograph of the section of the composite board obtained in Example 3 by adhesion of a shaft material.

Orientation by Extrusion <Example 1>
30 parts of vinyl chloride resin, 30 parts of furan resin, 20 parts of natural scaly graphite (average particle diameter 5 μm), and 20 parts of pitch-based graphitic carbon fiber (HC600-15M, Nippon Graphite Fiber, average diameter 7 μm, average length 150 μm) Then, a diallyl phthalate monomer was added as a plasticizer, dispersed with a Henschel mixer, kneaded with three rolls, and pelletized with a pelletizer to obtain a molding composition.

This molding composition was formed into a rod shape by an extrusion molding machine equipped with a die having a diameter of 20 mm, the carbon fibers were oriented in the extrusion direction, and treated in an air oven at 180 ° C. for 3 hours to obtain a carbon precursor. . Thereafter, the temperature was raised at 15 ° C. per hour in nitrogen gas, and the mixture was calcined and carbonized by holding at 1000 ° C. for 3 hours to obtain a shaft material having a diameter of 17 mm. The sound velocity in the axial direction of the obtained shaft material (that is, the thickness direction as described later) is measured by a water immersion method using an ultrasonic probe, the density is measured, and the acoustic impedance is calculated from the sound velocity and the density (sound velocity) × Calculated by (density). The results are shown in Table 1. Moreover, the micrograph of the cross section of an axial direction (thickness direction) and the direction of a surface perpendicular | vertical to an axis | shaft (namely, plate | board surface direction as mentioned later) is shown in FIG. 1 and FIG.
The obtained shaft material is cut to a required length before firing or carbonization or after firing / carbonization to obtain a composite plate having a required thickness. In this case, the axial direction of the shaft material before cutting corresponds to the “thickness direction” of the composite plate after cutting, and the direction of the surface perpendicular to the axis corresponds to the “plate surface direction” of the composite plate.
<Comparative Example 1>
The molding composition obtained in Example 1 was formed into a sheet shape by an extrusion molding machine equipped with a sheet die having a diameter of 2.0 mm, and the carbon fibers were oriented in the extrusion direction. In an air oven at 180 ° C. To give a carbon precursor. Thereafter, the temperature was raised at 15 ° C./hour in nitrogen gas, and the mixture was baked and carbonized at 1000 ° C. for 3 hours to obtain a sheet material having a thickness of 1.5 mm. The sound speed in the thickness direction of the obtained sheet material was measured in the same manner as in Example 1, the density was measured, and the acoustic impedance was calculated from (sound speed) × (density) from the sound speed and density. The results are shown in Table 1.

As can be seen from FIG. 1 and FIG. 2, in the composite plate obtained in Example 1, the graphite particles and the carbon fibers are oriented in the thickness direction of the composite plate. As a result, a high acoustic impedance value of 11.6 Mrayl is obtained. Moreover, since it is considered that the graphite particles and the carbon fibers are oriented in the same direction as after the firing even before the resin is fired, the composite plate based on the cured resin before firing is also used as the acoustic matching layer. It is understood that it is useful.

Orientation by magnetic field <Example 2>
90 parts of furan resin and 10 parts of flaky graphite (UP-5N average particle diameter 5 μm made by Japanese graphite or UP-20N average particle diameter 20 μm made by Japanese graphite), 3 parts of p-toluenesulfonic acid and methanol solution 3 as a curing agent Were added and subjected to vacuum degassing with sufficient stirring at room temperature using a high speed homomixer.

  This solution is poured into a 2 mm thick mold, applied with a magnetic field of 1 Tesla in the thickness direction with a YS variable electromagnet (manufactured by Tamagawa Seisakusho), heat-cured, treated in an air oven at 180 ° C. for 3 hours, and carbon precursor. The body. Thereafter, the temperature was raised at 15 ° C./hour in nitrogen gas and maintained at 1400 ° C. for 3 hours to obtain a sheet material having a thickness of 1.5 mm.

For the obtained sheet material, the sound velocity and density were measured in the same manner as in Example 1 to calculate the value of acoustic impedance, and the thermal conductivity in the thickness direction was measured with a laser flash thermophysical property measuring apparatus LFA457 manufactured by NETZSCH. did. The results are shown in Table 2. FIG. 4 shows a micrograph of a cross section in the thickness direction of the graphite using an average particle diameter of 5 μm.
<Comparative example 2>
A sheet material having a thickness of 1.5 mm was obtained in the same process as in Example 2, but without applying a magnetic field. The results are shown in Table 2. FIG. 3 shows a micrograph of a cross section in the thickness direction of the graphite using an average particle diameter of 5 μm.

As can be seen from FIGS. 3 and 4, by applying a magnetic field in the thickness direction before the resin is cured, the graphite particles are oriented in the thickness direction, so that the acoustic impedance value is improved as shown in Table 2. . Since the value of thermal conductivity is improved by the anisotropy of the thermal conductivity of graphite, it is also useful as a heat radiating member. In addition, since it is considered that the graphite particles are oriented in the same direction as after firing even before the resin is fired, the composite plate based on the cured resin before firing is also used as the acoustic matching layer and the heat dissipation member. It is understood that it is useful.

  Even if carbon fiber is used instead of graphite, it is confirmed that the carbon fiber is oriented in the thickness direction by applying a magnetic field in the thickness direction.

Adhesion of shaft material <Example 3>
Bundle a 0.5mm sharp core (uni Nano Dia 0.5mm HB) and add 3 parts of p-toluenesulfonic acid and 3 parts of methanol solution as curing agent to 100 parts of furan resin in the gap. The mixture was sufficiently stirred at room temperature and poured, degassed by a vacuum degassing operation, heat-cured, and then treated in an air oven at 180 ° C. for 3 hours. Table 3 below shows the results of measuring and calculating the characteristics in the thickness direction in the same manner as in Example 1. Moreover, the photograph of the cross section is shown in FIG.

  A part of the embodiment of the present invention is described in the following items <1> to <12>.
<1> a plate-shaped base material;
  A composite plate comprising crystalline carbon powder dispersed in the base material and oriented in a direction perpendicular to the plate surface.
<2> The composite plate according to Item 1, wherein the base material includes amorphous carbon.
<3> The composite plate according to Item 1 or 2, wherein the base material includes a cured resin.
<4> The composite plate according to any one of items 1 to 3, wherein the crystalline carbon powder is uniformly dispersed in the base material.
<5> The composite plate according to any one of items 1 to 4, wherein the crystalline carbon powder is graphite particles and / or carbon fibers.
<6> Disperse the crystalline carbon powder uniformly in the resin,
  The resin in which the crystalline carbon powder is uniformly dispersed is molded into a rod shape by an extruder,
  The molded product is heated to cure the resin,
  A method for producing a composite plate, comprising cutting the molded product into a plate having a required thickness by cutting the molded product to a required length before or after curing the resin.
<7> The composite according to item 6, wherein the resin is a carbon-containing resin, and further includes firing and carbonizing a molded product obtained by curing the resin in a non-oxidizing atmosphere before or after the cutting. A manufacturing method of a board.
<8> Disperse the crystalline carbon powder uniformly in the resin,
  Applying a magnetic field in the thickness direction in the mold to the resin in which the crystalline carbon powder is uniformly dispersed,
  A method for producing a composite plate, comprising curing a resin to which a magnetic field is applied.
<9> The method for producing a composite plate according to Item 8, wherein the resin is a carbon-containing resin, and further includes firing and carbonizing the resin in a non-oxidizing atmosphere after the curing.
<10> A plurality of shaft materials including a rod-shaped base material of amorphous carbon or a cured resin and a crystalline carbon powder oriented in the axial direction of the base material and uniformly dispersed in the base material,
  Injecting resin into the gap between the bundled shaft members to bond the shaft members to each other,
  A method for producing a composite plate, comprising curing a resin injected into the gap.
<11> The shaft material includes a shaft material, a pencil core, or a sharp core, in which crystalline carbon powder is uniformly dispersed in a resin, formed into a rod shape with an extruder, and fired in a non-oxidizing atmosphere. Item 10. A method for producing a composite plate according to Item 10.
<12> The method for producing a composite plate according to any one of items 6 to 11, wherein the crystalline carbon powder is graphite particles and / or carbon fibers.

Claims (11)

A plate-shaped base material;
An acoustic matching layer comprising graphite particles dispersed in the base material and oriented in a direction perpendicular to the plate surface. The acoustic matching layer according to claim 1, wherein the base material includes amorphous carbon. The acoustic matching layer according to claim 1, wherein the base material includes a cured resin. The acoustic matching layer according to claim 1, wherein the graphite particles are uniformly dispersed in the base material. The acoustic matching layer according to claim 1, wherein the graphite particles are natural scaly graphite particles and / or flaky graphite particles. Disperse the graphite particles uniformly in the resin,
A resin in which the graphite particles are uniformly dispersed is formed into a rod shape with an extruder,
The molded product is heated to cure the resin,
6. The method according to claim 1 , comprising cutting the molded product to a required length in a direction perpendicular to the extrusion direction before or after curing the resin to obtain a plate having a required thickness. A method for producing an acoustic matching layer . The acoustic matching layer according to claim 6, wherein the resin is a carbon-containing resin, and further includes firing and carbonizing the molded product obtained by curing the resin in a non-oxidizing atmosphere before or after the cutting. Manufacturing method. Disperse the graphite particles uniformly in the resin,
Applying a magnetic field in the thickness direction in the mold to the resin in which the graphite particles are uniformly dispersed,
The method for producing an acoustic matching layer according to claim 1 , comprising curing a resin to which a magnetic field is applied. The method for producing an acoustic matching layer according to claim 8, wherein the resin is a carbon-containing resin, and further includes baking and carbonizing the resin in a non-oxidizing atmosphere after the curing. A bundle of a plurality of shafts including a rod-shaped base material of amorphous carbon or cured resin and graphite particles oriented in the axial direction of the base material and uniformly dispersed in the base material,
Injecting resin into the gap between the bundled shaft members to bond the shaft members to each other,
Curing the resin injected into the gap ; and
The shaft member comprises a plate and be Rukoto the desired thickness and cut to a required length at the axial direction perpendicular manufacturing the acoustic matching layer according to any one of claims 1 to 5 Method. The shaft material is
A shaft material in which graphite particles are uniformly dispersed in a resin, formed into a rod shape with an extruder , and fired in a non-oxidizing atmosphere , or
The method for producing an acoustic matching layer according to claim 10, comprising an unfired shaft material in which graphite particles are uniformly dispersed in a resin and formed into a rod shape by an extruder .