Thermal insulation container and ridge magnetometer using the same

Abstract

A thermally insulated container (10) is provided with an inner container (11) and an outer container (14) that surrounds the inner container (11) with a gap (15) in between. The inner container (11) and the outer container (14) are made of a fiber-reinforced plastic in which a resin is impregnated in a base material. The inner container (11) is provided with a cylindrical container (13) and a second cylindrical container (22) that have a storage portion (23) and a storage portion (24) in which a refrigerant (16) is stored inside, and a refrigerant injection pipe (12) through which the refrigerant (16) is injected. The storage portion (24) is in communication with the storage portion (23). The base material that constitutes a prescribed region of the second cylindrical container (22) and a prescribed region of the outer container (14) includes a fabric. The prescribed region of the outer container (14) also includes a honeycomb sheet.

Description

Technical Field

[0001] This invention relates to insulated containers and spinal magnetometers using the same. Background Technology

[0002] In the medical field, a device (magnetometer) has been developed to measure the magnetic field generated by the neural activity of the spinal cord. The magnetometer uses a superconducting quantum interference device (SQUID) that utilizes the principle of superconductivity to measure the weak magnetic field generated by the spinal cord.

[0003] For a squid to exhibit a superconducting state, it needs to be immersed in a refrigerant such as liquid helium. Therefore, the spindle magnetometer requires a highly insulating container capable of storing the refrigerant for extended periods. Furthermore, the material constituting the insulating container needs to be a non-magnetic material unaffected by magnetism.

[0004] For example, Patent Document 1 discloses an ultra-low temperature container comprising an inner container made of fiber-reinforced plastics (FRP) and an outer container surrounding the inner container, and a magnetic detection device comprising the ultra-low temperature container. The inner container is filled with a liquid having a low boiling point, and a magnetic detection sensor is disposed in the liquid. In addition, the gap between the inner container and the outer container is a vacuum.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 7-302933 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] To measure weak magnetic fields, the distance (lift-off) between the SQUID and the measurement site on the spinal cord needs to be as short as possible. In particular, the insulating container between the SQUID and the measurement site on the spinal cord needs to maintain its insulating function while making the walls of the insulating container as thin as possible.

[0010] Regarding the inner and outer containers disclosed in Patent Document 1, their walls are relatively thick to improve thermal insulation. Therefore, there is a problem that the SQUID has difficulty detecting weak magnetic fields.

[0011] The present invention is made in view of the above circumstances, and its object is to provide a thermally insulated container with excellent thermal insulation and thin walls, and a spinal magnetometer using the same.

[0012] Methods for solving problems

[0013] In order to achieve the above objectives, [1] the heat-insulating container of the present invention comprises an inner container and an outer container surrounding the inner container with a gap, the inner container and the outer container being made of fiber-reinforced plastic impregnated with resin in a fiber-containing substrate, the inner container comprising a cylindrical container and a second cylindrical container having a receiving portion for storing refrigerant inside, and a refrigerant injection pipe for injecting refrigerant into the cylindrical container, the receiving portion of the second cylindrical container communicating with the receiving portion of the cylindrical container, the substrate constituting a predetermined area of ​​the second cylindrical container and a predetermined area of ​​the outer container comprising a fabric, the predetermined area of ​​the outer container further comprising a honeycomb sheet, the fabric being laminated on one side and the other side of the honeycomb sheet.

[0014] Alternatively, [2] the aforementioned fabric may be composed of at least one of the following: glass fiber, alumina fiber, and carbon fiber.

[0015] Alternatively, [3] the substrate constituting the aforementioned outer container may also include a unidirectional fiber sheet formed by multiple fibers twisted together in one direction, and the aforementioned unidirectional fiber sheet may be stacked on at least one of the surfaces of the aforementioned honeycomb sheet and the other surface.

[0016] Alternatively, [4] the fibers of the aforementioned unidirectional fiber sheet constituting the aforementioned defined area of ​​the aforementioned outer container are parallel to the extending direction of the aforementioned second cylindrical container's core.

[0017] Alternatively, [5] the substrate constituting the aforementioned defined area of ​​the second cylindrical container may also include a unidirectional fiber sheet formed by multiple fibers twisted together in one direction.

[0018] Alternatively, [6] the fibers of the aforementioned unidirectional fiber sheet constituting the aforementioned defined area of ​​the aforementioned second cylindrical container may be orthogonal to the extension direction of the core of the aforementioned second cylindrical container.

[0019] Alternatively, [7] the outer container may surround the second cylindrical container when the unidirectional fiber sheet constituting the aforementioned outer container is facing the unidirectional fiber sheet constituting the aforementioned second cylindrical container.

[0020] Alternatively, [8] the aforementioned unidirectional fiber sheet constituting the aforementioned defined area of ​​the aforementioned outer container may be composed of at least one selected from the group consisting of glass fiber, alumina fiber and carbon fiber.

[0021] Alternatively, [9] the unidirectional fiber sheet constituting the aforementioned defined area of ​​the aforementioned second cylindrical container may be composed of at least one selected from the group consisting of glass fiber, alumina fiber, and carbon fiber.

[0022] Alternatively,

[10] the thickness of the aforementioned honeycomb sheet can be 1 to 7 mm.

[0023] Alternatively,

[11] the aforementioned resin may include epoxy resin.

[0024] In addition,

[12] the spinal magnetometer of the present invention comprises: a superconducting quantum interference device for detecting magnetic fields generated by a living organism, and a heat-insulating container described in any one of [1] to

[11] , wherein the superconducting quantum interference device is immersed in a refrigerant stored in the aforementioned containment portion of the aforementioned second cylindrical container.

[0025] The effects of the invention

[0026] According to the present invention, it is possible to provide a heat-insulating container with excellent thermal insulation and thin walls, as well as a spinal magnetometer using the same. Attached Figure Description

[0027] [ Figure 1 [Image 1] is a schematic side view of an insulated container according to one embodiment of the present invention.

[0028] [ Figure 2 [Image 1] is a schematic top view of an insulated container according to one embodiment of the present invention.

[0029] [ Figure 3 ]yes Figure 2 A sectional view along the AA line.

[0030] [ Figure 4 ] is to show Figure 3 A schematic diagram of the refrigerant injection pipe is shown.

[0031] [ Figure 5 [Illustration] is a schematic diagram showing the structure of a unidirectional fiber sheet.

[0032] [ Figure 6 ] is to show Figure 3 A schematic diagram showing the structure of the cylindrical portion of the cylindrical container.

[0033] [ Figure 7 ] is to show Figure 3 A schematic cross-sectional view showing a modified example of the cylindrical portion of a cylindrical container.

[0034] [ Figure 8 ]yes Figure 2 BB line sectional view.

[0035] [ Figure 9 [Illustrated view] is a schematic cross-sectional view of a spinal magnetometer of a heat-insulating container according to one embodiment of the present invention. Detailed Implementation

[0036] The following provides a detailed description of an insulated container and a spinal magnetometer using the same, according to embodiments of the present invention. These embodiments are illustrative of the invention and are not intended to limit the invention to the following description. The invention can be implemented with appropriate modifications within its scope.

[0037] (Implementation Method)

[0038] The heat-insulating container 10 of the embodiment will be described. Figure 1 This is a side view of the insulated container 10. Figure 2 This is a top view of the insulated container 10. Figure 3 yes Figure 2 A sectional view along line AA of the insulated container 10 is shown. Figure 3 As shown, the insulated container 10 is a container for storing refrigerant 16. The insulated container 10 has an inner container 11 and an outer container 14 that surrounds the inner container 11 through a gap 15.

[0039] The inner container 11 and the outer container 14 will be described.

[0040] [Content container 11]

[0041] The inner container 11 includes: a cylindrical container 13 having a receiving portion 23 for storing refrigerant 16 inside; a refrigerant injection pipe 12 installed in the cylindrical container 13; and a second cylindrical container 22 having a receiving portion 24 for storing refrigerant 16 inside. The receiving portion 24 communicates with the receiving portion 23. The cylindrical container 13 has an upper surface portion 131 forming an upper surface, a cylindrical portion 132 forming a side wall, and a bottom portion 133 forming a bottom surface. The refrigerant injection pipe 12 is installed in the upper surface portion 131. It should be noted that the refrigerant injection pipe 12 may also be installed in the cylindrical portion 132. Here, the "inner" of the inner container 11 refers to the area formed by the surfaces that the refrigerant 16 can contact.

[0042] The refrigerant injection pipe 12, the cylindrical container 13, and the second cylindrical container 22 will be described.

[0043] [Refrigerant Injection Pipe 12]

[0044] The refrigerant injection pipe 12 is a pipe used to inject refrigerant 16 into the cylindrical container 13. The pipe can also be made of cylindrical, elliptical, or square shapes.

[0045] From the viewpoint of improving thermal insulation and exhibiting rigidity in the temperature range below -196°C achieved by refrigerant 16 at room temperature, the thickness of the wall constituting the refrigerant injection pipe 12 is preferably 2 to 30 mm, more preferably 2.5 to 15 mm. Hereinafter, the "temperature range below -196°C" will be referred to as the "ultra-low temperature range". Furthermore, the thickness of the wall constituting the refrigerant injection pipe 12 refers to the thickness of the wall constituting the refrigerant injection pipe 12 on a plane orthogonal to the length direction (height direction).

[0046] The length of the refrigerant injection pipe 12 is set according to the size of the outer container 14 and the inner container 11, for example, 100 to 500 mm.

[0047] When the refrigerant injection pipe 12 is cylindrical, from the viewpoint of suppressing the evaporation of refrigerant 16, the diameter (inner diameter) of the refrigerant injection pipe 12 is, for example, 50 to 300 mm.

[0048] When the refrigerant injection pipe 12 is elliptical in shape, the length of its major axis is, for example, 50 to 300 mm.

[0049] When the refrigerant injection pipe 12 is in the shape of a square tube, the length of the diagonal in the cross section of the pipe body in the plane orthogonal to the length direction (height direction) of the refrigerant injection pipe 12 is, for example, 100 to 400 mm.

[0050] The refrigerant injection pipe 12 is made of fiber reinforced plastic (FRP), which consists of a substrate 21 and a resin impregnated in the substrate 21.

[0051] Here, the cured state of the resin constituting the FRP is the state in which the curing reaction has been fully completed (hereinafter also referred to as the "C-stage state"). In the following description, unless otherwise specified, the cured state of the FRP is the C-stage state. The same applies in other embodiments.

[0052] The FRP substrate 21 constituting the refrigerant injection pipe 12 is composed of at least one selected from the group consisting of glass fiber, alumina fiber, and carbon fiber. From the viewpoints of cost, processability, and availability, and from the viewpoint of reducing thermal conductivity in the range from room temperature to extremely low temperature, the substrate 21 is preferably glass fiber.

[0053] To slow down heat conduction from the outside to the cylindrical container 13 via the refrigerant injection pipe 12, such as Figure 4As shown, the fibers constituting the substrate 21 are wound into a spiral shape in the extending direction of the core CL of the refrigerant injection tube 12. The angle θ between the orientation direction of the fibers and the extending direction of the core CL of the refrigerant injection tube 12 is 50 to 89°. From the viewpoint of slowing down heat conduction in the refrigerant injection tube 12 and improving rigidity, the angle θ is more preferably 55 to 70°.

[0054] The resin impregnated in the substrate 21 is composed of, for example, an epoxy resin composition with epoxy resin as the main agent, a phenolic resin composition with phenolic resin as the main agent, or a polyimide resin composition with thermosetting polyimide resin as the main agent.

[0055] From the viewpoint of slowing down heat conduction to the cylindrical container 13, the amount of resin impregnated in the substrate 21 is preferably 15 to 50 wt% relative to the total weight of the FRP constituting the refrigerant injection pipe 12.

[0056] Hereinafter, the proportion of resin impregnated in the substrate will be referred to as resin content (wt%). Resin content (wt%) is the amount of resin component contained in the FRP expressed as a proportion of the total weight of the FRP. Resin content (wt%) is expressed as: Resin content (wt%) = (Weight of resin (wt) × 100) / (Weight of fiber (wt) + Weight of resin (wt)). It should be noted that "weight of resin" refers to the weight of resin converted to solid components. The weight of resin converted to solid components refers to the weight of resin after removing, for example, volatile components such as solvents.

[0057] [Tubular container 13]

[0058] The cylindrical container 13 is a bottomed cylindrical container having a receiving portion 23 for storing refrigerant 16 inside. The receiving portion 23 is formed inside the cylindrical container 13. The cylindrical portion 132 constituting the cylindrical container 13 may also be formed in the shape of a cylinder, an elliptical cylinder, a square cylinder, etc.

[0059] From the viewpoint of improving thermal insulation and exhibiting rigidity in the extremely low temperature range, the thickness of the wall constituting the cylindrical container 13 is preferably 2 to 30 mm, more preferably 2.5 to 15 mm. Here, the thickness of the wall constituting the cylindrical container 13 refers to the thickness of the wall constituting the cylindrical portion 132.

[0060] For example, in the case of a device for measuring the magnetic field of the human body, the size of the cylindrical container 13 is preferably a size that can store 50 to 150 liters of refrigerant, from the viewpoint of enabling the device to operate for a long time.

[0061] The cylindrical portion 132 constituting the cylindrical container 13 is made of FRP impregnated with resin in a substrate. The substrate constituting the FRP is, for example, composed of fibers, fabrics, or unidirectional fiber sheets in which multiple fibers are unidirectionally filamented. To improve the thermal insulation of the cylindrical container 13, the substrate preferably contains fibers or unidirectional fiber sheets. In addition, to improve the rigidity of the cylindrical portion 132, the substrate is more preferably composed of a laminate of fabric and unidirectional fiber sheets.

[0062] i) When the substrate is made of fibers, the type of fibers is selected from at least one of the group consisting of glass fibers, alumina fibers, and carbon fibers. From the viewpoint of reducing thermal conductivity in the extremely low temperature range, alumina fibers are preferred. The substrate may also be made of multiple fibers, such as alumina fibers and glass fibers. The fibers are wound into a spiral shape relative to the extending direction of the core of the cylindrical portion 132. The angle of winding the fibers relative to the extending direction of the core of the cylindrical portion 132 is 50 to 89°.

[0063] ii) When the substrate is made of fabric, the fabric is woven from fibers selected from at least one of the group consisting of glass fibers, alumina fibers, and carbon fibers. Examples of fabric weaving methods include satin weave, plain weave, and twill weave. The fabric is layered in a manner forming a tube. For example, the fabric is layered with the warp yarns at +45° and the weft yarns at -45° relative to the extension direction of the core of the tube 132. Alternatively, the fabric can be layered with the warp yarns at 0° and the weft yarns at 90° relative to the extension direction of the core of the tube 132. Furthermore, from the viewpoint of exhibiting pseudo-isotropic rigidity, for example, one fabric can be arranged with the warp yarns at +45° and the weft yarns at -45° relative to the extension direction of the core of the tube 132, and other fabrics can be layered on top of it with the warp yarns at 0° and the weft yarns at 90°, repeating this layering operation. It should be noted that the angles formed by the warp and weft threads relative to the extending directions of the core of the tubular portion 132 are not strictly defined, and an error in the angle is allowed to a degree that does not impair the rigidity of the tubular portion 132. The allowable range of this angle is, for example, ±10°, and preferably ±5° relative to a specified angle.

[0064] iii) When the substrate is composed of a unidirectional fiber sheet, the unidirectional fiber sheet is composed of at least one selected from the group consisting of glass fiber, alumina fiber, and carbon fiber. Figure 5 This is a front view of a unidirectional fiber sheet. As shown, the unidirectional fiber sheet is composed of multiple flat filaments 66 twisted together in one direction. To prevent the twisted flat filaments 66 from deforming, the unidirectional fiber sheet is held in place, for example, by a fixing filament 65. Figure 6 As shown, the angle between the unidirectional fiber sheet, for example, the fiber of the flat filament 66 and the extending direction of the core CL of the tubular portion 132 is... It is wound into a spiral shape at an angle of 50 to 89 degrees to form a tube.

[0065] The resin impregnated in the substrate constituting the cylindrical container 13 is, for example, an epoxy resin composition with epoxy resin as the main component, a phenolic resin composition with phenolic resin as the main component, or a polyimide resin composition with thermosetting polyimide resin as the main component. From the viewpoint of exhibiting rigidity and toughness of the cylindrical container 13 in the range of room temperature to extremely low temperatures, and from the viewpoint of ensuring good processability, the resin is preferably an epoxy resin composition. The resin may also be composed of two or more resin compositions.

[0066] From the viewpoint of maintaining the rigidity of the cylindrical container 13 when storing refrigerant 16, the amount of resin in the cylindrical container 13 is preferably 15 to 50 wt% relative to the total weight of the FRP constituting the cylindrical container 13.

[0067] The upper surface portion 131 and the bottom portion 133 of the cylindrical container 13 are made of FRP impregnated with resin in a substrate. The substrate is, for example, fabric. Multiple layers of fabric are stacked. From the viewpoint that the expansion and contraction behavior of the cylindrical portion 132 and the refrigerant injection pipe 12 is the same as that of the upper surface portion 131 and the bottom portion 133 in the range of room temperature and extremely low temperatures, the resin is preferably the same as the resin constituting the cylindrical portion 132 and the refrigerant injection pipe 12. The amount of resin in the upper surface portion 131 is preferably 15 to 50 wt% relative to the total weight of the FRP constituting the upper surface portion 131. The amount of resin in the bottom portion 133 is preferably 15 to 50 wt% relative to the total weight of the FRP constituting the bottom portion 133. The thickness of the upper surface portion 131 and the bottom portion 133 is, for example, the same as the thickness of the cylindrical portion 132.

[0068] Examples of refrigerants 16 include liquid oxygen, liquid nitrogen, and liquid helium. For applications involving the measurement of the magnetic field of the spinal cord, liquid helium is preferred.

[0069] [Second cylindrical container 22]

[0070] The second cylindrical container 22 has a cylindrical portion 122 forming its sidewall and a bottom portion 123 that blocks one end of the cylindrical portion 122. The second cylindrical container 22 is fixed to the cylindrical portion 132 of the cylindrical container 13. A receiving portion 24 is formed inside the second cylindrical container 22. The receiving portion 24 communicates with the receiving portion 23 of the cylindrical container 13.

[0071] The second cylindrical container 22 is airtightly fixed to the cylindrical portion 132 in such a way that the length direction of the second cylindrical container 22 is orthogonal to the length direction of the cylindrical portion 132.

[0072] The second cylindrical container 22 is composed of shapes such as cylindrical, elliptical, or square. The square cylindrical container contains a column with a cross-section of a square, trapezoidal, or rectangular shape in a plane orthogonal to the length direction of the second cylindrical container 22.

[0073] The thickness of the wall of the cylindrical portion 122 constituting the second cylindrical container 22 can also be the same as the thickness of the wall constituting the cylindrical container 13. When the heat-insulating container 10 is used in the apparatus for measuring the magnetic field of the spinal cord, from the viewpoints of shortening lift-off and improving heat insulation, the thickness of the wall constituting the second cylindrical container 22 is preferably 2 to 15 mm, more preferably 2.5 to 10 mm. Here, lift-off refers to the distance from the measurement surface of the superconducting quantum interference device to the measurement site of the spinal cord.

[0074] Regarding the size of the second cylindrical container 22, for example, in the case of using the insulated container 10 in the device for measuring the magnetic field of the spinal cord, it is preferable to have a size that can store 10 to 30 liters of refrigerant 16 in the case of the second cylindrical container 22 alone.

[0075] The cylindrical portion 122 is located between the object to be measured and the measuring device, and has a defined area opposite to them. Therefore, the structure (basic structure) of the area outside the defined area of ​​the cylindrical portion 122 will be described first.

[0076] The cylindrical portion 122 has a cylindrical shape and is made of FRP, which consists of a substrate and a resin impregnated in the substrate. The substrate is made of i) fabric, ii) unidirectional fiber sheet, or iii) fabric and unidirectional fiber sheet. From the viewpoint of suppressing deformation of the cylindrical portion 122, the substrate is preferably made of ii) unidirectional fiber sheet, or iii) fabric and unidirectional fiber sheet.

[0077] i) When the substrate is made of fabric, the fabric is woven from at least one fiber selected from the group consisting of glass fiber, alumina fiber, and carbon fiber. From the viewpoint of maintaining the rigidity of the tubular portion 122 and ensuring good processability, the fiber is preferably glass fiber or alumina fiber. The substrate may also be composed of two or more types of fiber. Examples of weaving methods for the fabric include satin weave, plain weave, and twill weave. From the viewpoint of shape retention, the weaving method of the fabric is preferably satin weave.

[0078] For example, the fabric can be layered with the warp yarns at 0° and the weft yarns at 90° relative to the extending direction of the core of the tubular portion 122. Alternatively, the fabric can be layered with the warp yarns at +45° and the weft yarns at -45°. Furthermore, from the viewpoint of exhibiting pseudo-isotropic rigidity, a fabric can be arranged with the warp yarns at 0° and the weft yarns at 90° relative to the extending direction of the core of the tubular portion 122, and other fabrics can be layered on top of this fabric with the warp yarns at +45° and the weft yarns at -45°.

[0079] ii) When the substrate is composed of unidirectional fiber sheets, the unidirectional fiber sheets are composed of at least one selected from the group consisting of glass fiber, alumina fiber, and carbon fiber. From the viewpoint of maintaining the rigidity of the cylindrical portion 122 and ensuring good processability, the fiber is preferably glass fiber or alumina fiber. The substrate may also be composed of two or more types of fiber. From the viewpoint of suppressing deformation of the cylindrical portion 122, the unidirectional fiber sheets are preferably stacked in a manner in which the fibers of the unidirectional fiber sheets are orthogonal (90°) to the extending direction of the core of the cylindrical portion 122.

[0080] iii) When the substrate is composed of fabric and unidirectional fiber sheets, from the viewpoint of suppressing deformation of the tubular portion 122, the substrate has a configuration in which the fabric is laminated on at least one side of the unidirectional fiber sheet, the unidirectional fiber sheet is laminated on both sides of the fabric, or the fabric and unidirectional fiber sheets are alternately laminated. From the viewpoint of improving rigidity, the fabric and unidirectional fiber sheets are preferably configured to be linearly symmetrical in the thickness direction with reference to the fabric or unidirectional fiber sheet located at the center when viewing the cross-section of the wall of the tubular portion 122. For example, the fabric and unidirectional fiber sheets preferably have a configuration in which the fabric is laminated on both sides of the unidirectional fiber sheet with the unidirectional fiber sheet as the center. From the viewpoint of suppressing deformation of the tubular portion 122, the unidirectional fiber sheets are preferably laminated in such a way that the fibers of the unidirectional fiber sheets are orthogonal (90°) to the extending direction of the axis of the tubular portion 122. It should be noted that orthogonality can be non-strict, allowing for errors in the degree to which the rigidity of the tubular portion 122 is not compromised. The allowable range of this angle is, for example, 90° ± 15°.

[0081] Next, with Figure 8 The structure of the specified area of ​​the cylindrical part 122 will be explained using an example. Figure 8 yes Figure 2 The diagram shows a sectional view along line BB of the insulated container 10. The "defined area" refers to the region located between the object to be measured 101 and the measuring device 102 during the use of the insulated container 10, where a thin wall is desired to minimize lift-off. The defined area of ​​the cylindrical portion 122 is formed by… Figure 8 The area indicated by the mark 111 can be a portion of the upper wall or the entire upper wall. It should be noted that the "defined area" of the outer container 14 will be described later.

[0082] The specified area 111 is made of FRP. The substrate of FRP is i) fabric, or ii) fabric and unidirectional fiber sheet.

[0083] i) When the substrate is made of fabric, the composition of the substrate in the specified region 111 is substantially the same as that when the substrate outside the specified region 111 is made of fabric. That is, the fabric is woven from at least one fiber selected from the group consisting of glass fiber, alumina fiber, and carbon fiber. From the viewpoint of maintaining the rigidity of the tubular portion 122 and ensuring good processability, the fiber is preferably glass fiber or alumina fiber. The substrate may also be composed of two or more types of fibers. Examples of weaving methods for the fabric include satin weave, plain weave, and twill weave. From the viewpoint of shape retention, the weaving method of the fabric is preferably satin weave.

[0084] On the other hand, ii) when the substrate in the designated area 111 is composed of fabric and unidirectional fiber sheets, the structure is substantially the same as when the substrate outside the designated area 111 is composed of fabric and unidirectional fiber sheets. That is, from the viewpoint of suppressing deformation of the tubular portion 122, the substrate has a configuration in which fabric is laminated on at least one side of the unidirectional fiber sheet, a configuration in which unidirectional fiber sheets are laminated on both sides of the fabric, or a configuration in which fabric and unidirectional fiber sheets are alternately laminated.

[0085] When the substrate in the designated area 111 contains a unidirectional fiber sheet, from the viewpoint of improving rigidity, the substrate is preferably configured to be linearly symmetrical in the thickness direction with reference to the fabric or unidirectional fiber sheet located at the center when viewing the cross-section of the wall of the cylindrical portion 122. For example, the fabric and unidirectional fiber sheet preferably have a configuration in which the fabric is laminated on both sides of the unidirectional fiber sheet with the unidirectional fiber sheet as the center. From the viewpoint of suppressing deformation of the cylindrical portion 122, the unidirectional fiber sheet is preferably laminated in such a way that the fibers of the unidirectional fiber sheet are orthogonal (90°) to the extending direction of the axis of the cylindrical portion 122. It should be noted that orthogonality can be non-strict, allowing for an error in the degree to which the rigidity of the cylindrical portion 122 is not compromised. The allowable range of this angle is, for example, 90° ± 15°.

[0086] When the substrate in the designated region 111 contains unidirectional fiber sheets, the unidirectional fiber sheets exhibit high rigidity relative to stress, thus the FRP has high rigidity. Therefore, compared to when the substrate is made of fabric, it is possible to form a relatively thin wall while ensuring high rigidity. As a result, for example, during the use of the insulation container 10, the measuring device 102 can be brought close to the object to be measured 101. From the viewpoint of maintaining rigidity, the designated region 111 is preferably the entire area of ​​the upper wall of the cylindrical portion 122.

[0087] When the cylindrical portion 122 is cylindrical, the defined area 111 of the cylindrical portion 122 is a part of the circumferential surface (curved surface) of the semi-cylinder that constitutes half of the cylinder, or the entire circumferential surface (curved surface) of the semi-cylinder.

[0088] From the viewpoint of maintaining rigidity, the amount of resin in the designated area 111 and outside the designated area 111 of the cylindrical portion 122 is 15 to 50 wt% relative to the total weight of the FRP constituting the cylindrical portion 122.

[0089] The resin impregnated in the substrate constituting the cylindrical portion 122 is, for example, an epoxy resin composition with epoxy resin as the main component, a phenolic resin composition with phenolic resin as the main component, or a polyimide resin composition with thermosetting polyimide resin as the main component. From the viewpoint of possessing rigidity and toughness in both room temperature and extremely low temperature ranges, and from the viewpoint of ensuring good processability, an epoxy resin composition is preferred. The resin may also be composed of two or more resin compositions.

[0090] The bottom portion 123 is made of FRP (fiberglass reinforced plastic), which consists of a substrate and a resin impregnated in the substrate. The substrate is composed of multiple layers of fabric. From the viewpoint of ensuring that the expansion and contraction behavior of the cylindrical portion 122 is the same as that of the bottom portion 123 in the range from room temperature to extremely low temperatures, the resin is preferably the same as the resin constituting the cylindrical portion 122. From the viewpoint of maintaining the rigidity of the cylindrical container 13 when storing refrigerant, the amount of resin in the bottom portion 123 is preferably 15 to 50 wt%, relative to the total weight of the FRP in the bottom portion 123, and is the same as that in the cylindrical portion 122.

[0091] The receiving portion 23 of the cylindrical container 13 and the receiving portion 24 of the second cylindrical container 22 can also be connected and fixed via a component such as a pipe. In this case, the component used to connect the receiving portion 23 and the receiving portion 24 is preferably made of the same material as that constituting the cylindrical container 13 and the second cylindrical container 22.

[0092] Examples of methods for joining the cylindrical container 13 and the second cylindrical container 22 include: applying an adhesive to the joint surfaces of the cylindrical container 13 and the second cylindrical container 22 for airtight joining; forming threads on the joint surfaces of the cylindrical container 13 and the second cylindrical container 22, applying an adhesive, and then threading them together for airtight joining. Preferably, the joining method is an airtight joining that maintains the gap 15 in a vacuum state.

[0093] From the viewpoint of exhibiting good adhesion, the adhesive used is preferably the same resin as the resin constituting the refrigerant injection pipe 12 and the cylindrical container 13. Examples of resins include epoxy resin compositions with epoxy resin as the main component, phenolic resin compositions with phenolic resin as the main component, and polyimide resin compositions with thermosetting polyimide resin as the main component. From the viewpoint of possessing rigidity and toughness in the range from room temperature to extremely low temperatures, and from the viewpoint of ensuring good adhesion, epoxy resin compositions are preferred. The resin may also be composed of two or more resin compositions.

[0094] [Outer Container 14]

[0095] like Figure 3 As shown, the outer container 14 is configured to surround the inner container 11 through a gap 15. The upper surface of the outer container 14 supports the cylindrical container 13 via a refrigerant injection pipe 12. In the insulated container 10, the end face of the refrigerant injection pipe 12 and the surface of the upper surface of the outer container 14 exist on the same plane.

[0096] Here, "encircling" refers to the state in which the outer container 14 surrounds the inner container 11 through the gap 15. The "inside" of the outer container 14 refers to the area in the outer container 14 that is in contact with the gap 15. The part that will become the upper surface of the outer container 14 is called the "upper surface part".

[0097] From the viewpoint of improving the thermal insulation effect, the gap 15 is preferably in a vacuum state. The outer container 14 has a degree of rigidity that allows it to maintain its shape even when the gap 15 is in a vacuum state.

[0098] The shape and size of the outer container 14 are not limited as long as it can surround the inner container 11. From the viewpoint of preventing container deformation when the gap 15 is in a vacuum state, the outer container 14 is preferably made of a rounded shape that can disperse stress. In particular, the corners of the outer container 14 are preferably formed of a shape with a large radius of curvature. This prevents the contraction stress of the container associated with vacuum from concentrating in specific parts of the container.

[0099] For the outer container 14, it is also divided into Figure 8 The defined region 112 located between the object to be measured 101 and the measuring device 102, and the region outside therethere, will be described. First, the composition of the region outside the defined region 112 will be described.

[0100] From the viewpoint of preventing container deformation when the gap 15 is in a vacuum state, the thickness of the wall constituting the outer container 14 is preferably greater than or equal to the thickness of the cylindrical container 13 and the second cylindrical container 22.

[0101] The portion of the outer container 14 outside the designated area 112 is made of FRP, which consists of a substrate and a resin impregnated in the substrate. The substrate constituting the designated area 112 of the outer container 14 may also be made of i) fabric, or ii) fabric and unidirectional fiber sheet.

[0102] When the substrate is made of fabric, the fabric is woven from at least one fiber selected from the group consisting of glass fiber, alumina fiber, and carbon fiber. From the viewpoint of maintaining rigidity and ensuring good processability, the fibers constituting the fabric are preferably glass fiber and alumina fiber. The substrate may also be composed of two or more types of fibers. Examples of weaving methods for the fabric include satin weave, plain weave, and twill weave. From the viewpoint of shape retention, the weaving method of the fabric is preferably satin weave.

[0103] The fabric can be layered, for example, with the warp yarns at 0° and the weft yarns at 90° relative to the extending direction of the axis of the second cylindrical container 22, or with the warp yarns at +45° and the weft yarns at -45°. Alternatively, from the viewpoint of exhibiting rigidity through pseudo-isotropy, a fabric can be arranged with the warp yarns at 0° and the weft yarns at 90° relative to the extending direction of the axis of the second cylindrical container 22, and other fabrics can be layered on top of this fabric with the warp yarns at +45° and the weft yarns at -45°. Here, the allowable range of the angles formed by the warp and weft yarns relative to the extending direction of the axis of the second cylindrical container 22 is ±10°, preferably ±5°.

[0104] The resin constituting the area outside the designated region 112 of the outer container 14 is, for example, an epoxy resin composition with epoxy resin as the main component, a phenolic resin composition with phenolic resin as the main component, or a polyimide resin composition with thermosetting polyimide resin as the main component. From the viewpoint of possessing rigidity and toughness in the range from room temperature to extremely low temperatures, and from the viewpoint of ensuring good processability, the resin is preferably an epoxy resin composition. The resin may also be composed of two or more resin compositions.

[0105] Next, refer to Figure 8 The structure of the defined area 112 of the outer container 14 is described below. The defined area 112 of the outer container 14 is also made of FRP. The substrate constituting the defined area 112 of the outer container 14 is made of i) fabric, or ii) fabric and unidirectional fiber sheet.

[0106] i) When the substrate is made of fabric, its composition is the same as that of the substrate of other parts of the outer container 14. That is, the fabric is woven from at least one fiber selected from the group consisting of glass fiber, alumina fiber, and carbon fiber. From the viewpoint of maintaining rigidity and ensuring good processability, the fibers constituting the fabric are preferably glass fiber and alumina fiber. The substrate may also be composed of two or more types of fibers. Examples of weaving methods for the fabric include satin weave, plain weave, and twill weave. From the viewpoint of shape retention, the weaving method of the fabric is preferably satin weave.

[0107] ii) Next, if the substrate is composed of a fabric and a unidirectional fiber sheet, the fabric is substantially the same as the fabric of the substrate constituting the other parts of the outer container 14. The unidirectional fiber sheet is composed of at least one fiber selected from the group consisting of glass fiber, alumina fiber, and carbon fiber. From the viewpoint of maintaining rigidity and ensuring good processability, the fiber is preferably glass fiber or alumina fiber. The fiber may also be composed of two or more types of fiber.

[0108] From the viewpoint of improving rigidity and suppressing deformation of the outer container 14, the unidirectional fiber sheet is preferably stacked in a manner parallel (0°) to the extending direction of the fibers constituting the unidirectional fiber sheet relative to the axis of the second cylindrical container 22 (cylindrical portion 122). Here, parallel (0°) allows for an error in the degree to which the rigidity of the outer container 14 is not reduced. The allowable range of the angle is ±10°, preferably ±5°.

[0109] The load on the measured object 101 is applied to a designated area 112 of the outer container 14, requiring greater rigidity than other parts. Therefore, as Figure 8 As shown in the enlarged view of circle 2, the outer container 14 further includes a honeycomb sheet 70 with high shear strength and contributing to thermal insulation within the FRP constituting the designated area 112. The honeycomb sheet 70 is made of, for example, aramid honeycomb sheets, paper honeycomb sheets, or non-combustible honeycomb sheets. From the viewpoint of ensuring rigidity, the honeycomb sheet 70 is preferably an aramid honeycomb sheet. Regarding the dimensions of the polygonal, for example, hexagonal cells constituting the honeycomb sheet 70, the length of one side of the cell is 3 to 10 mm, and preferably 3 to 5 mm from the viewpoint of maintaining thermal insulation and preserving the honeycomb shape. The thickness (height) of the honeycomb sheet is 1 to 7 mm, and preferably 1 to 3 mm from the viewpoint of maintaining thermal insulation and thinning the walls of the outer container 14. The cells are voids, which improves thermal insulation. The voids in the cells can be vacuum or contain air.

[0110] When the substrate of the designated area 112 is made of fabric, the fabric is laminated on both sides of the honeycomb sheet 70. On the other hand, when the substrate of the designated area 112 is made of fabric and unidirectional fiber sheet, it is preferable that the unidirectional fiber sheet is laminated on at least one side or the other side of the honeycomb sheet 70. For example, the FRP of the designated area 112 of the outer container 14 has the following configuration: i) fabric is laminated on both sides of the honeycomb sheet 70, and a unidirectional fiber sheet is laminated on at least one fabric; ii) unidirectional fiber sheets are laminated on both sides of the honeycomb sheet 70, and fabric is laminated on these unidirectional fiber sheets; iii) a unidirectional fiber sheet is laminated on one side of the honeycomb sheet 70, and fabric is laminated on the unidirectional fiber sheet, and fabric is laminated on the other side of the honeycomb sheet 70.

[0111] When the substrate constituting the designated region 112 of the outer container 14 includes fabric and unidirectional fiber sheets, the designated region 112 has higher rigidity than when the substrate is fabric. Therefore, the wall of the designated region 112 constituting the outer container 14 can be thinned. In addition, compared with a structure formed only by fabric, the structure formed by fabric and unidirectional fiber sheets is less prone to deformation of the designated region of the outer container 14 even when the wall is thinned.

[0112] From the viewpoint of improving thermal insulation and rigidity, the specified area 112 of the outer container 14 is preferably larger (wider) than the specified area 111 of the second cylindrical container 22.

[0113] The resin constituting the designated region 112 of the outer container 14 can be the same as the resin constituting the region other than the designated region 112. That is, the resin is, for example, composed of an epoxy resin composition with epoxy resin as the main component, a phenolic resin composition with phenolic resin as the main component, or a polyimide resin composition with thermosetting polyimide resin as the main component. From the viewpoint of having rigidity and toughness in the range from room temperature to extremely low temperatures, and from the viewpoint of ensuring good processability, the resin is preferably an epoxy resin composition. The resin may also be composed of two or more resin compositions.

[0114] It should be noted that the FRP substrate for the portion of the outer container 14 outside the designated area 112 may also be composed of fabric and unidirectional fiber sheets. In this case, from the viewpoint of suppressing deformation of the outer container 14, the fabric and unidirectional fiber sheets may have a configuration in which the fabric is laminated on at least one side of the unidirectional fiber sheet, a configuration in which the unidirectional fiber sheet is laminated on both sides of the fabric, or a configuration in which the fabric and unidirectional fiber sheets are alternately laminated.

[0115] From the viewpoint of maintaining the rigidity of the outer container 14 when storing refrigerant 16, the amount of resin in the specified area 112 of the outer container 14 is preferably 15 to 50 wt% relative to the total weight of the FRP constituting the outer container 14.

[0116] It should be noted that a support body (not shown) that supports the load and fixes the cylindrical container 13 and the second cylindrical container 22 to a fixed position can also be configured in the gap 15.

[0117] The outer container 14 is hermetically connected to the refrigerant injection pipe 12. Examples of methods for connecting the outer container 14 and the refrigerant injection pipe 12 include applying an adhesive to the mating surfaces of the outer container 14 and the refrigerant injection pipe 12 to achieve a hermetically connected connection; or forming threads on the mating surfaces of the outer container 14 and the refrigerant injection pipe 12, applying an adhesive, and then threading them together to achieve a hermetically connected connection.

[0118] In the above embodiment, a cylindrical portion 132 consisting of a single-layer wall has been described, but the wall of the cylindrical portion 132 may also be composed of multiple layers. Furthermore, refrigerant injection pipes 12 and the like, having the same cylindrical shape, may also be composed of multiple layers. For example, such as... Figure 7 As shown in circle 1, the cylindrical portion 132 can also be composed of an outer layer 132O and an inner layer 132I. The outer layer 132O forms a layer close to the void 15 (outer), and the inner layer 132I forms a layer close to the refrigerant 16 (inner).

[0119] The outer layer 132O and the inner layer 132I are both made of FRP. The substrate constituting the FRP is fiber or unidirectional fiber sheet. The substrate material is glass or alumina.

[0120] From the viewpoints of ensuring the rigidity of the cylindrical portion 132, reducing the thermal conductivity of the cylindrical portion 132, and suppressing costs, the substrate constituting the outer layer 132O is preferably fiber or unidirectional fiber sheet. The substrate material is preferably glass. The substrate constituting the inner layer 132I is preferably fiber or unidirectional fiber sheet. The substrate material is preferably alumina.

[0121] The substrates constituting the outer layer 132O and the inner layer 132I are respectively wound into a spiral shape relative to the extending direction of the core of the cylindrical portion 132. The inclination of the fibers constituting the fibers or unidirectional fiber sheets relative to the extending direction of the core of the cylindrical portion 132 can be different or the same in the outer layer 132O and the inner layer 132I. From the viewpoint of improving the rigidity of the cylindrical portion 132 and improving operability (demolding from the mold), the inclination of the fibers constituting the inner layer 132I or the unidirectional fiber sheets is preferably greater than the inclination of the fibers constituting the outer layer 132O or the unidirectional fiber sheets. Preferably, the outer layer 132O and the inner layer 132I have the same thickness, or the inner layer 132I is thicker than the outer layer 132O. The ratio of the thickness of the inner layer 132I to the thickness of the outer layer 132O is 50:50 to 80:20, preferably 50:50 to 70:30, and more preferably 50:50 to 60:40.

[0122] From the viewpoint of preventing interlayer delamination, it is preferable to use the same resin for impregnating the substrate constituting the outer layer 132O and the inner layer 132I.

[0123] When the FRP of the cylindrical portion 132 is configured as a two-layer structure, the FRP of the upper surface portion 131 and the bottom portion 133 is also preferably configured as a two-layer structure. From the viewpoint of slowing down heat conduction from the outside to the entire inner container 11 via the refrigerant injection pipe 12, the material of the outer fiber constituting the upper surface portion 131 and the bottom portion 133 is, for example, glass, and the material of the inner fiber constituting the inner layer is, for example, alumina. The resin constituting the upper surface portion 131 and the bottom portion 133 is preferably the same resin as the resin constituting the cylindrical portion 132.

[0124] The manufacturing methods of the refrigerant injection pipe 12, the cylindrical container 13, the second cylindrical container 22, and the outer container 14 will be described below.

[0125] [Manufacturing method of refrigerant injection pipe 12]

[0126] The manufacturing method of the refrigerant injection tube 12 includes: a molding process in which a fiber impregnated with liquid resin, i.e., a substrate, is spirally wound onto a rod-shaped mold to form the shape of the refrigerant injection tube 12; a curing process in which the resin is cured by heating; and a demolding process in which the cured refrigerant injection tube 12 is removed from the mold.

[0127] The molding process can employ a molding method such as filament winding. The angle at which the fiber is wound around the mold is 50 to 89° relative to the extending direction of the mold's core.

[0128] In the curing process, the temperature and time used to cure the resin can be appropriately set according to the type and amount of resin. For example, when using an epoxy resin composition as the resin and the amount of resin is set to 20-50 wt%, the heating temperature is 80-150°C and the curing time is 1-12 hours.

[0129] In the demolding process, after cooling to room temperature, the refrigerant injection pipe 12 is removed from the mold, thus obtaining the refrigerant injection pipe 12.

[0130] [Manufacturing method of cylindrical container 13]

[0131] An example of a method for manufacturing the cylindrical container 13 will be described. The cylindrical portion 132 constituting the cylindrical container 13 is obtained by impregnating a prepreg blank, which is made by impregnating a substrate composed of fibers, fabrics, unidirectional fiber sheets, etc., with resin, winding it around a rod-shaped mold while taking into account the orientation of the fibers, curing it, and cutting it into a predetermined shape. The upper surface portion 131 and the bottom portion 133 constituting the cylindrical container 13 are obtained by stacking prepreg blanks, curing them, and cutting them into predetermined shapes. Here, the prepreg blank refers to a composite material that, although the resin curing reaction has proceeded to the middle, is in a state where it has not fully entered stage B.

[0132] Next, the formed upper surface portion 131 is hermetically joined to the cylindrical portion 132. Examples of joining methods include joining the mating surfaces of the upper surface portion 131 and the cylindrical portion 132 with an adhesive, or forming threads on the mating surfaces of the upper surface portion 131 and the cylindrical portion 132 and then threading them together. Alternatively, an adhesive that cures at room temperature can be applied to the threads before threading. This hermetically seals the mating surfaces. The bottom portion 133 and the cylindrical portion 132 can also be joined using the same method as the joining method for the upper surface portion 131 and the cylindrical portion 132. In this way, the cylindrical container 13 is completed.

[0133] Other examples of the manufacturing method for the cylindrical container 13 will be described. The manufacturing method includes: a prepreg preparation step, in which a prepreg is prepared by impregnating a substrate with resin and then heating it; a molding step, in which the prepreg is bonded to the surface of a mold shaped as the cylindrical container 13 to form a prepreg; a curing step, in which the prepreg is cured by heating and pressurizing; and a demolding step, in which the cured prepreg is removed from the mold.

[0134] In the prepreg fabrication process, the impregnation time of the resin in the substrate and the temperature of the heated fabric after impregnation are appropriately set according to the type of resin and the amount of resin adhering to the fabric (resin amount). For example, when the resin is an epoxy resin composition and the resin amount is 20-50 wt%, the time is 1-12 hours and the temperature is 80-150°C.

[0135] In the molding process, the prepreg blank is cut to correspond to the shape of the cylindrical container 13. The prepreg blank is then glued to the mold for molding. In cases where the mold has a complex shape, the prepreg blank is cut into smaller pieces and glued to the mold for molding. This allows the prepreg blank to follow the shape of the mold.

[0136] In the curing process, the prepreg preform is cured by heating and pressurizing. For example, an autoclave forming method using an autoclave can be employed. This allows for uniform curing of the prepreg preform.

[0137] In the demolding process, the prepreg blank is cooled to room temperature and removed from the mold. Then, a cylindrical container 13 is obtained.

[0138] Alternatively, for example, if the cylindrical portion 132 is an FRP composed of two layers of walls, the cylindrical portion 132 can be manufactured by, for example, a filament winding method.

[0139] When the substrate constituting the inner layer is alumina fiber and the substrate constituting the outer layer is glass fiber, the cylindrical portion 132 is manufactured as follows: Alumina fiber impregnated with resin is spirally wound onto a rod-shaped mold. Next, glass fiber impregnated with resin is spirally wound onto the wound alumina fiber, forming a cylindrical portion 132 with two layers of walls. Then, the resin constituting the cylindrical portion 132 is cured by heating. After cooling to room temperature, the cylindrical portion 132 is removed from the mold, resulting in a cylindrical portion 132 with two layers of walls.

[0140] The upper surface portion 131 and the lower surface portion 133 are also made into two-layer walls. The manufacturing method of the upper surface portion 131 includes: a prepreg blank manufacturing process, in which a prepreg blank with a fabric woven from alumina fibers as the base material and a prepreg blank with a fabric woven from glass fibers as the base material are respectively manufactured; a lamination process, in which the two types of prepreg blanks are laminated with two layers of walls; and a curing process, in which the laminated prepreg blanks are cured. The lower surface portion 133 is manufactured by the same manufacturing method as the upper surface portion 131.

[0141] The joining method of the upper surface portion 131, which is composed of two layers of walls, and the joining method of the bottom portion 133, which is composed of two layers of walls, and the joining method of the cylindrical portion 132 can be the same as the joining method of the upper surface portion 131 and the cylindrical portion 132.

[0142] [Manufacturing method of the second cylindrical container 22]

[0143] For the second cylindrical container 22, the cylindrical portion 122 and the bottom portion 123 constituting the second cylindrical container 22 are respectively manufactured.

[0144] First, the manufacturing method of the tubular portion 122, whose substrate is made of fabric, will be described. The manufacturing method of the tubular portion 122 includes: a fabric prepreg fabrication process, which produces a fabric prepreg fabric with fabric as the substrate; a fabric prepreg fabric forming process, which forms the tubular portion 122 by pasting the fabric prepreg fabric onto the surface of a mold in the form of a mold in which the extension direction of the warp or weft yarn is orthogonal to the extension direction of the mold core; a curing process, which cures the stacked fabric prepreg fabric; and a demolding process, which removes the cured fabric prepreg fabric from the mold.

[0145] In the fabric prepreg fabrication process, resin is impregnated into the fabric. The fabric is then heated. The heating time and temperature are appropriately set according to the type of resin and the amount of resin adhering to the fabric (resin amount). For example, when the resin is an epoxy resin composition and the resin amount is 20–50 wt%, the heating time is 1–12 hours and the heating temperature is 80–150°C.

[0146] In the prepreg forming process, the prepreg is cut to fit the size of the mold. The prepreg is then glued to the mold to form the fabric. The prepreg is formed, for example, by gluing the warp or weft yarns constituting the fabric orthogonally to the direction of extension of the mold's axis.

[0147] In the curing process, the fabric prepreg blank is cured by heating and pressurizing. For example, an autoclave forming method using an autoclave can be employed. This allows the fabric prepreg blank to cure uniformly.

[0148] In the demolding process, the prepreg blank is cooled to room temperature and removed from the mold. Then, the cylindrical part 122 is obtained.

[0149] Next, the bottom surface 123 is manufactured using the same method as the bottom surface 133. The second cylindrical container 22 is obtained by joining the manufactured bottom surface 123 to the cylindrical portion 122. The joining method between the bottom surface 123 and the cylindrical portion 122 can be the same as the joining method between the bottom surface 133 and the cylindrical portion 132.

[0150] Next, the manufacturing method of the tubular portion 122, whose substrate is composed of fabric and unidirectional fiber sheet, will be described. The manufacturing method of the tubular portion 122, whose substrate is composed of fabric and unidirectional fiber sheet, includes: a prepreg fabrication step, which prepares a fabric prepreg fabric based on fabric and a UD prepreg fabric based on unidirectional fiber sheet; a first forming step of the fabric prepreg fabric, in which the fabric prepreg fabric is bonded to the surface of a mold shaped as the tubular portion 122 in such a way that the extension direction of the warp or weft yarns of the fabric is orthogonal to the extension direction of the core of the mold and formed; a UD prepreg fabric forming step, in which the UD prepreg fabric is bonded to the fabric prepreg fabric in such a way that the fibers of the unidirectional fiber sheet are orthogonal to the extension direction of the core of the mold and formed; a second forming step of the fabric prepreg fabric, in which the fabric prepreg fabric is bonded to the UD prepreg fabric in such a way that the extension direction of the warp or weft yarns of the fabric is orthogonal to the extension direction of the core of the mold and formed; a curing step, in which the stacked prepreg fabrics are cured; and a demolding step, in which the cured prepreg fabrics are removed from the mold.

[0151] In the prepreg fabrication process, resin is impregnated into the fabric and then into the unidirectional fiber sheet. The fabric and unidirectional fiber sheet are then heated separately. The heating time and temperature are appropriately set according to the type of resin and the amount of resin adhering to the fabric and unidirectional fiber sheet (resin amount). For example, when the resin is an epoxy resin composition and the resin amount is 20–50 wt%, the heating time is 1–12 hours and the heating temperature is 80–150°C.

[0152] In the first forming process of the fabric prepreg, the fabric prepreg is cut to the size of the mold. The fabric prepreg is then glued to the mold to form the fabric. The fabric prepreg is glued in such a way that the warp or weft yarns constituting the fabric extend orthogonally to the axis of the mold.

[0153] In the UD prepreg molding process, the UD prepreg is formed by bonding the unidirectional fiber sheet to the fabric prepreg in such a way that the fibers of the unidirectional fiber sheet extend orthogonally relative to the axis of the mold. The area where the UD prepreg is bonded to the fabric prepreg is formed only needs to be at least a predetermined area 111 in the cylindrical portion 122. From the viewpoint of improving the rigidity of the cylindrical portion 122 and suppressing the deformation of the cylindrical portion 122, it is preferable that the UD prepreg is bonded to the entire area of ​​the fabric prepreg for molding.

[0154] In the second forming process of the fabric prepreg preform, the fabric prepreg preform is cut according to the size of the mold. The fabric prepreg preform is then bonded onto the bonded UD prepreg preform to form the preform. The fabric prepreg preform is bonded in such a way that the warp or weft yarns of the fabric are orthogonal to the extending direction of the mold core.

[0155] In the curing process, the prepreg preform is cured by heating and pressurizing. For example, an autoclave forming method using an autoclave can be employed. This allows for uniform curing of the prepreg preform.

[0156] In the demolding process, the prepreg blank is cooled to room temperature and removed from the mold. Then, the cylindrical part 122 is obtained.

[0157] The manufacturing method of the tubular portion 122, whose substrate is made of unidirectional fiber sheets, is the same as the manufacturing method of the tubular portion 122, whose substrate is made of fabric and unidirectional fiber sheets, except for the process involving the fabric.

[0158] When the configuration of the designated region 111 within the cylindrical portion 122 differs from that of other regions, a manufacturing method that can achieve the desired configuration is adopted for the designated region 111, and for other regions, a manufacturing method that can achieve the desired configuration is adopted as long as possible.

[0159] [Manufacturing method of outer container 14]

[0160] The outer container 14 is made in three parts: a first part that surrounds the cylindrical container 13, a second part that surrounds the second cylindrical container 22, and a third part that surrounds the bottom part 123.

[0161] First, an example of the manufacturing method for Part 1 will be described. When the substrate of the FRP is made of fabric, the manufacturing method for Part 1 includes: a fabric prepreg fabrication process, which produces a fabric prepreg fabric with the fabric as the substrate; a fabric prepreg fabric forming process, which forms the fabric prepreg fabric by pasting it onto the surface of a mold that is shaped to surround the outer container 14 of the cylindrical container 13; a curing process, which cures the stacked fabric prepreg fabric by heating and pressurizing; and a demolding process, which removes the cured fabric prepreg fabric from the mold.

[0162] In the fabric prepreg fabrication process, resin is impregnated into the fabric used as the substrate. The fabric is then heated. The heating time and temperature are appropriately set according to the type of resin and the amount of resin adhering to the fabric (resin amount). For example, when the resin is an epoxy resin composition and the resin amount is 20–50 wt%, the heating time is 1–12 hours and the heating temperature is 80–150°C.

[0163] In the fabric prepreg molding process, the fabric prepreg is cut to fit the size of the mold. The fabric prepreg is then glued to the mold to form the fabric.

[0164] In the curing process, the fabric prepreg preform is cured by heating and pressurizing. For example, an autoclave forming method using an autoclave can be employed. This allows the fabric prepreg preform to cure uniformly.

[0165] In the demolding process, the prepreg blank is cooled to room temperature and removed from the mold. Part 1 is obtained through the above method.

[0166] Next, an example of the manufacturing method for the second part of the outer container 14 will be described. When the substrate is made of fabric, the method for manufacturing the second part includes: a fabric prepreg fabrication process, in which a fabric prepreg fabric is made using the fabric as the substrate; a first fabric prepreg fabric forming process, in which the fabric prepreg fabric is bonded to the surface of a mold forming the second part of the outer container 14, which surrounds the second cylindrical container 22, such that the warp or weft yarns of the fabric extend parallel to the extension direction of the mold's core; a honeycomb sheet lamination process, in which honeycomb sheets 70 are laminated over a designated area 112 of the bonded fabric prepreg fabric; a second fabric prepreg fabric forming process, in which the fabric prepreg fabric is bonded over the honeycomb sheets 70 and over the fabric prepreg fabric formed in the first fabric prepreg fabric forming process, such that the warp or weft yarns of the fabric extend parallel to the extension direction of the mold's core; a curing process, in which the laminated fabric prepreg fabric is cured; and a demolding process, in which the cured fabric prepreg fabric is removed from the mold.

[0167] In the fabric prepreg fabrication process, resin is impregnated into the fabric used as the substrate. The fabric is then heated. The heating time and temperature are appropriately set according to the type of resin and the amount of resin adhering to the fabric (resin amount). For example, when the resin is an epoxy resin composition and the resin amount is 20–50 wt%, the heating time is 1–12 hours and the heating temperature is 80–150°C.

[0168] In the first forming process of the prepreg preform, the prepreg preform is cut to correspond to the shape of the second part of the outer container 14. The prepreg preform is then bonded to a mold for forming. The prepreg preform is bonded in such a way that the warp or weft yarns of the fabric extend parallel to the direction of the mold's axis. Alternatively, the prepreg preform can be bonded while being exposed to warm air at 50–100°C.

[0169] In the honeycomb sheet lamination process, the honeycomb sheet 70 is placed on a predetermined area that becomes a prepreg blank.

[0170] In the second forming process of the prepreg preform, the prepreg preform is further bonded to the honeycomb sheet 70 and the prepreg preform along the shape of the mold to form the prepreg preform. The prepreg preform is bonded in such a way that the warp or weft yarns of the fabric are parallel to the extending direction of the mold core. The prepreg preform can also be bonded and formed while being exposed to warm air at 50-100°C.

[0171] In the curing process, the stacked prepreg blanks are cured by heating and pressurizing. For example, an autoclave forming method using an autoclave can be employed. This allows the prepreg blanks to cure uniformly.

[0172] In the demolding process, the prepreg blank is cooled to room temperature and removed from the mold. Then, the outer container 14 surrounding the second cylindrical container 22 is obtained.

[0173] Next, an example of a method for manufacturing the second part when the substrate is composed of fabric and unidirectional fiber sheet will be described. This manufacturing method includes: a prepreg fabrication step, in which a fabric prepreg fabric based on a fabric substrate and a UD prepreg fabric based on a unidirectional fiber sheet are prepared; a first forming step of the fabric prepreg fabric, in which the fabric prepreg fabric is bonded to the surface of a mold forming the second part of the outer container 14, which is shaped to surround a predetermined area 111 of the second cylindrical container 22, such that the extending direction of the warp or weft yarns of the fabric is parallel to the extending direction of the mold's core; a honeycomb sheet lamination step, in which honeycomb sheets are laminated over the predetermined area 112 of the fabric prepreg fabric; and the fabric prepreg... The second prepreg molding process involves bonding a prepreg onto the honeycomb sheet and the prepreg formed in the first prepreg molding process, with the warp or weft yarns of the fabric extending parallel to the direction of the mold core. The UD prepreg molding process involves bonding a unidirectional fiber sheet onto the prepreg with the fibers of the fiber sheet parallel to the direction of the mold core. The curing process cures the stacked prepreg. The demolding process removes the cured prepreg from the mold.

[0174] In the prepreg fabrication process, resin is impregnated into the fabric and unidirectional fiber sheet respectively, and then heated to produce fabric prepregs in stage B and UD prepregs. The heating time and temperature are appropriately set according to the type of resin and the amount of resin attached to the fabric and unidirectional fiber sheet (resin amount). For example, when the resin is an epoxy resin composition and the resin amount is 20-50 wt%, the heating time is 1-12 hours and the heating temperature is 80-150°C.

[0175] In the first forming process of the fabric prepreg, the fabric prepreg is cut to the size of the mold. The fabric prepreg is then bonded to the mold to form the prepreg. The fabric prepreg is bonded in a manner that the warp or weft yarns of the fabric extend in a direction parallel to, for example, the direction of extension of the mold's core. Alternatively, the fabric prepreg can be bonded while being exposed to warm air at 50–100°C.

[0176] In the honeycomb sheet lamination process, the honeycomb sheet 70 is placed on a predetermined area that becomes a prepreg blank.

[0177] In the second forming process of the fabric prepreg preform, the fabric prepreg preform is cut according to the size of the mold. This fabric prepreg preform is then bonded onto the honeycomb sheet 70 and the fabric prepreg preform to form the preform. The fabric prepreg preform is bonded in a manner where the extension direction of the warp or weft yarns of the fabric is parallel to, for example, the extension direction of the mold's core axis. Alternatively, the fabric prepreg preform can be bonded while being exposed to warm air at 50–100°C.

[0178] In the UD prepreg molding process, the UD prepreg is formed by bonding the fibers of a unidirectional fiber sheet onto a fabric prepreg in a manner parallel to the extension direction of the mold core. The area where the UD prepreg is bonded onto the fabric prepreg and formed includes at least the area that forms the defined area 112 of the outer container 14. From the viewpoint of improving the rigidity of the outer container 14 and suppressing deformation of the outer container 14, the UD prepreg is preferably bonded to the entire area of ​​the outer container 14 for molding.

[0179] In the curing process, the stacked prepreg blanks are cured by heating and pressurizing. For example, an autoclave forming method using an autoclave can be employed. This allows for uniform curing of the prepreg blanks.

[0180] In the demolding process, the prepreg blank is cooled to room temperature and removed from the mold. This yields the second part of the outer container 14.

[0181] The third part of the outer container 14 can be manufactured using the same method as the bottom part 123. Next, the first part and the third part of the outer container 14 are joined airtightly. The joining method can be the same as the joining method used for the bottom part 123 and the cylindrical part 122.

[0182] The insulated container 10 is completed by joining the various parts thus formed. Specifically, the second cylindrical container 22 is hermetically joined to the cylindrical portion 132 of the cylindrical container 13. Next, the refrigerant injection pipe 12 is hermetically joined to the cylindrical container 13. Then, the first, second, and third portions of the outer container 14 are respectively arranged and hermetically joined in a manner that surrounds the inner container 11.

[0183] Next, through pre-formed or newly formed air holes, the air in the gap 15 is vented using a vacuum pump or the like. When the pressure in the gap 15 reaches below a reference value, the air holes are airtightly sealed using resin or the like. The heat-insulating container 10 is thus completed using the above method. The joining of the various parts can be performed using the same method as the joining of the bottom part 123 and the cylindrical part 122.

[0184] The heat-insulating container 10 described in Embodiment 1 can be used, for example, as a heat-insulating container for use in the medical field. Hereinafter, application examples using the heat-insulating container 10 will be described.

[0185] [Application Example 1]

[0186] As an example of an application using the insulated container 10, a spinal magnetometer 60 can be cited.

[0187] like Figure 9As shown, the spinal magnetometer 60 includes a superconducting quantum interference device 17 for detecting the magnetic field generated by a living organism 18, and a heat-insulating container 10. The heat-insulating container 10 includes an inner container 11 and an outer container 14 surrounding the inner container 11 through a gap 15. The inner container 11 includes a cylindrical container 13 having a housing 23 for storing refrigerant 16, a refrigerant injection pipe 12 installed in the cylindrical container 13, and a second cylindrical container 22 having a housing 24 for storing refrigerant 16. The superconducting quantum interference device 17 is housed in the second cylindrical container 22, immersed in the refrigerant 16 stored in the second cylindrical container 22. Figure 9 As shown, the organism 18 is placed horizontally above the spinal cord portion of the organism 18 and the measurement surface 19 of the superconducting quantum interference device 17.

[0188] like Figure 9 As shown in the magnified view of circle 3, a defined area of ​​the outer container 14 has a structure in which fabric 63 is laminated on one side of the honeycomb sheet 71 and fabric 64 is laminated on the other side. The superconducting quantum interference device 17 is housed in the second cylindrical container 22 while immersed in refrigerant 16. In addition, the measuring surface 19 is opposite to the honeycomb sheet 71.

[0189] The substrate constituting the designated region 112 of the outer container 14 may also include fabric 63 and unidirectional fiber sheets. The unidirectional fiber sheets are laminated between the honeycomb sheet 71 and the fabric 63. The unidirectional fiber sheets may also be laminated on top of the fabric 63. The unidirectional fiber sheets may also be laminated between the honeycomb sheet 71 and the fabric 64. The unidirectional fiber sheets may also be laminated below the fabric 64. Furthermore, from the viewpoint of ensuring the rigidity of the outer container 14 and suppressing deformation of the outer container 14 under external pressure and stress, the unidirectional fiber sheets are preferably laminated in a manner where the fiber extension direction is parallel to the axis of the second cylindrical container 22.

[0190] The substrate constituting the designated region 111 of the second cylindrical container 22 may also include fabric and unidirectional fiber sheets. From the viewpoint of ensuring the rigidity of the designated region 111 of the second cylindrical container 22 and suppressing the deformation of the second cylindrical container 22 under internal pressure, the unidirectional fiber sheet preferably has fibers that are orthogonal to the extension direction of the axis of the second cylindrical container 22.

[0191] Furthermore, when the substrate constituting the designated region 112 of the outer container 14 contains a unidirectional fiber sheet, the measurement surface 19 of the superconducting quantum interference device 17 faces the surface of the unidirectional fiber sheet constituting the designated region 112 of the outer container 14. When the substrate constituting the designated region 111 of the second cylindrical container 22 contains a unidirectional fiber sheet, the measurement surface 19 of the superconducting quantum interference device 17 faces the surface of the unidirectional fiber sheet constituting the designated region 111 of the second cylindrical container 22.

[0192] [Effect]

[0193] The heat-insulating container 10 and the spinal magnetometer 60 using it achieve the following effects.

[0194] In the heat-insulating container 10, the substrate constituting the designated area 112 of the outer container 14 includes fabric 63 and fabric 64, and the designated area 112 of the outer container 14 includes a honeycomb sheet 71. Fabric 63 is laminated on one side of the honeycomb sheet 71, and fabric 64 is laminated on the other side. As a result, the heat insulation performance of the heat-insulating container 10 is improved.

[0195] By including unidirectional fiber sheets in the substrate constituting the designated region 112 of the outer container 14, the rigidity of the outer container 14 can be ensured. With the unidirectional fiber sheets constituting the designated region 112 of the outer container 14 facing each other, and the unidirectional fiber sheets constituting the designated region 111 of the second cylindrical container 22, the outer container 14 surrounds the second cylindrical container 22. Thus, the heat-insulating container 10 has the rigidity to withstand external stress, internal pressure, and external pressure even when the gap 15 is a vacuum.

[0196] Furthermore, by including unidirectional fiber sheets exhibiting high rigidity to stress in the substrate of the designated region 111 of the second cylindrical container 22 and the designated region 112 of the outer container 14, the designated regions 111 and 112 of the second cylindrical container 22 and the outer container 14 respectively possess rigidity. That is, by including both fabric and unidirectional fiber sheets to achieve the same rigidity as a structure containing only fabric, the wall thickness can be reduced. In other words, using the spinal magnetometer 60 of the insulated container 10 can shorten the distance (lifting) from the measurement surface 19 of the superconducting quantum interference device 17 to the spinal cord (measurement site) of the organism 18.

[0197] Furthermore, using a spinal magnetometer 60 with a heat-insulating container 10 equipped with a refrigerant injection pipe 12 reduces heat conduction from the outside to the cylindrical container 13 and the second cylindrical container 22 via the refrigerant injection pipe 12. As a result, the refrigerant 16 can be stored in the heat-insulating container 10 for a longer period of time, thus extending the operating time of the spinal magnetometer 60.

[0198] Example

[0199] To evaluate the thermal insulation performance of the outer container 14 constituting the thermal insulation container 10, samples were prepared according to the configurations of the embodiments and comparative examples described in Table 1, and the thermal conductivity was measured. Furthermore, to evaluate the rigidity caused by differences in the lamination configuration of the walls constituting the outer container 14 and the rigidity caused by differences in the lamination configuration of the walls constituting the second cylindrical container 22, samples were prepared according to the configurations of the embodiments and comparative examples described in Tables 1 and 2, and the flexural strength and flexural modulus were measured. It should be noted that the present invention is not limited to any of the following embodiments.

[0200] The resins, substrates, and honeycomb sheets used in the examples and comparative examples are as follows.

[0201] (resin)

[0202] (1) Matrix Resin A

[0203] (1-1) Main agent: Bisphenol A type epoxy resin (manufactured by Dow Chemical Company, DER383LCL),

[0204] (1-2) Curing agent: Anhydride-based curing agent (Hitachi Chemical Industries, Ltd., HN-2000)

[0205] (1-3) Curing accelerator: N,N-dimethylbenzylamine (manufactured by Kao Corporation, Kaolizer No. 20).

[0206] (2) Matrix resin B

[0207] (2-1) Main agent: Bisphenol A type epoxy resin (manufactured by DIC Company, EPICLON 850),

[0208] (2-2) Curing agent: Amine-based curing agent (manufactured by Nippon Carbide Industries, DICY),

[0209] (2-3) Curing accelerator: Dimethylbenzylamine (Kao Corporation, Kaolizer No. 20).

[0210] (Substrate and honeycomb sheet)

[0211] (1) Fabric (glass): Glass cloth (manufactured by Arisawa Fiber Glass Co., Ltd., ECC75181),

[0212] (2) Fabric (alumina): Alumina cloth (manufactured by Arisawa Seisakusho Co., Ltd., ALPT5107),

[0213] (3) Fabric (carbon): Carbon cloth (manufactured by Arisawa Seisakusho Co., Ltd., CFPH3113),

[0214] (4) UD (alumina): Unidirectional fiber sheet using alumina fibers (manufactured by Arisawa Seisakusho Co., Ltd., UDP-AL / CR8)

[0215] (5) UD (Glass): Unidirectional fiber sheet using glass fiber (manufactured by Arisawa Seisakusho Co., Ltd., UDP-GF / CR8),

[0216] (6) UD (Carbon): Unidirectional fiber sheet using carbon fiber (manufactured by Arisawa Seisakusho Co., Ltd., UDP-CF / CR8),

[0217] (7) Honeycomb core A (manufactured by TASUNS) thickness 1.2mm.

[0218] (8) Honeycomb sheet B (manufactured by TASUNS, honeycomb core) thickness 7.0mm.

[0219] Resins for impregnation into substrates were prepared separately.

[0220] (1) Preparation of resin

[0221] (1-1) Preparation of resin for use in prepreg preforms with fabric as substrate

[0222] The matrix resin A, curing agent, and curing accelerator were used. First, 100 parts by weight of the matrix resin, 88 parts by weight of the curing agent, and 0.8 parts by weight of the curing accelerator were added to a container. Then, the mixture was stirred at room temperature at 700 rpm for 60 minutes using a high-speed stirrer to obtain matrix resin A. The viscosity at this point was 500 mPa·s.

[0223] (1-2) Preparation of resin for prepreg blanks with substrate UD

[0224] The matrix resin B, curing agent, and curing accelerator were used. First, 100 parts by weight of the matrix resin, 88 parts by weight of the curing agent, and 0.8 parts by weight of the curing accelerator were added to a container. Then, the mixture was stirred at room temperature using a high-speed stirrer at 700 rpm for 60 minutes to obtain matrix resin B. The viscosity at this point was 500 mPa·s.

[0225] The prepared resin is used to make prepreg blanks.

[0226] (2) Preparation of prepreg blanks

[0227] (2-1) Fabrication of a prepreg blank with a woven fabric as the substrate

[0228] The matrix resin A was impregnated into the fabric with a cured resin content of 35 wt%. Next, it was dried at 130°C for 10 minutes to obtain a prepreg blank in stage B with a resin content of 35 wt%.

[0229] (2-2) Fabrication of UD prepreg blank with UD as the substrate

[0230] The matrix resin B was impregnated into UD with a cured resin content of 35 wt%. Next, it was dried at 130°C for 10 minutes to obtain a UD prepreg blank in the B stage with a resin content of 35 wt%.

[0231] The preparation of samples used for each determination, the determination methods, and the evaluation are as follows.

[0232] (3) Preparation of samples for evaluating the wall constituting the outer container 14

[0233] The test samples used to determine the thermal conductivity, flexural strength, and flexural modulus of the wall constituting the outer container 14 were prepared as follows. First, the prepreg blanks and honeycomb sheets prepared in (2-1) and (2-2) were laminated in the same manner as the laminated configurations of Examples 1-10 and Comparative Example 1 shown in Table 1. For the fabric prepreg blanks, during lamination, the bottommost prepreg blank was used as a reference, and the angle formed by that edge and the warp yarns was a predetermined angle. For the UD prepreg blanks, during lamination, the bottommost prepreg blank, which was used as a reference when laminating the fabric prepreg blanks, was used as a reference, and the angle formed by that edge and the fibers constituting the UD prepreg blanks was a predetermined angle. The predetermined angles refer to the angles shown in the examples and comparative examples recorded in Table 1. Next, the stacked prepreg blanks were pressed at 130°C for 90 minutes and 0.29 MPa with a cured resin content of 35 wt% and a cured thickness of 2.5 mm. After pressing, samples for measuring the C-stage state were obtained.

[0234] The test samples used to determine flexural strength and flexural modulus were cut into rectangles 10 mm wide and 20 mm long to maintain their size. The test samples from Examples 1-4 and Comparative Example 1 were cut with the long side of the test sample parallel to the warp yarns of the fabric prepreg constituting the test sample. The test samples from Examples 5-10 were cut with the long side of the test sample parallel to the fibers of the UD prepreg constituting the test sample. The reason for cutting the test samples from Examples 5-10 with the long side of the test sample parallel to the fibers of the UD prepreg is to properly evaluate the difference in effect (rigidity) caused by the difference in the fiber extension direction when using unidirectional fiber sheets as a substrate constituting the wall of the insulation container 10.

[0235] The test sample used to determine thermal conductivity is obtained by cutting a 2.5 mm thick plate-shaped test sample, which is used to determine thermal conductivity, flexural strength, and flexural modulus, into a circle with a diameter of 50 mm.

[0236] (4) Preparation of samples for evaluating the wall of the second cylindrical container 22

[0237] The test sample for determining the flexural strength and flexural modulus of the wall constituting the second cylindrical container 22 was prepared as follows. The prepreg blanks prepared in (2-1) and (2-2) were laminated in the same manner as the laminated configurations in Examples 11-18 shown in Table 2. During lamination, the prepreg blanks were laminated with the bottommost prepreg blank as a reference, and the angle between that edge and the warp yarns was a predetermined angle. In the case of laminated UD prepreg blanks, the UD prepreg blanks were laminated with the bottommost prepreg blank as a reference, and the angle between that edge and the fibers constituting the UD prepreg blanks was a predetermined angle. The predetermined angle refers to the angle shown in the examples described in Table 2. The laminated prepreg blanks were pressed at 130°C, 90 minutes, and 0.29 MPa with a cured resin content of 35 wt% and a cured thickness of 2.5 mm. After pressing, a test sample in the C-stage state was obtained. Then, the obtained test samples were cut into rectangles with a width of 10 mm and a length of 20 mm. The test samples from Examples 11 to 13 were cut so that the long side of the test sample was parallel to the warp yarns of the fabric prepreg constituting the test sample. The test samples from Examples 14 to 18 were cut so that the long side of the test sample was parallel to the fibers of the UD prepreg constituting the test sample.

[0238] (5) Determination of thermal conductivity

[0239] Thermal conductivity (W / m·K) was measured using a measuring apparatus (AGNE Gijutsu Center, ARC-TC-1000 model). The measurement was performed using the temperature slope method. Measurement conditions were in accordance with ASTM E1225.

[0240] (6) Determination of bending strength and flexural modulus

[0241] Flexural strength and flexural modulus of elasticity were measured using an automatic drafting testing machine (Shimadzu Corporation, AG-10). The measurement was performed using a three-point bending test (10 mm between supports, 2 mm / min test speed). During the test, the sample was placed on the testing machine with the supports at both ends of the three-point bending test aligned along the length of the sample. Flexural strength and flexural modulus of elasticity were calculated from the obtained maximum flexural stress (breaking load) according to JIS K7017.

[0242] Table 1 shows the results of the measurements of thermal conductivity, flexural strength, and flexural modulus of elasticity for Examples 1-10 and Comparative Example 1. Table 2 shows the results of the measurements of flexural strength and flexural modulus of elasticity for Examples 11-18.

[0243] [Table 1]

[0244]

[0245] [Table 2]

[0246]

[0247] Comparing the embodiments shown in Table 1 with each other, it can be seen that, for example, compared with Comparative Example 1, Example 1 can reduce thermal conductivity by about 80%. Furthermore, compared with Comparative Example 1, Example 8 can reduce thermal conductivity by about 50% while maintaining about 70% of the flexural strength.

[0248] Furthermore, comparing the embodiments and comparative examples shown in Table 2, it can be seen that, when the thickness is the same, for example, the bending strength of Embodiment 13 is about 1.7 times that of Embodiment 11. Additionally, it can be seen that the flexural modulus of Embodiment 17 is about 2.2 times that of Embodiment 11.

[0249] Based on these measurement results, by using the layered structure described in Examples 1 to 10 for the wall of the designated region 112 of the outer container 14 surrounding the second cylindrical container 22, the heat insulation performance of the heat-insulating container 10 can be improved. Furthermore, by using the layered structure described in Examples 11 to 18 for the wall of the designated region 111 of the second cylindrical container 22, the wall of the second cylindrical container 22 can be thinned while maintaining the rigidity of the wall of a conventional heat-insulating container. In addition, by using such a heat-insulating container 10 as the heat-insulating container of the spinal magnetometer 60, the distance (lift) from the measurement surface 19 of the superconducting quantum interference device 17 to the measurement site of the spinal cord can be shortened, making it possible to measure extremely weak magnetic fields.

[0250] Based on the above results, the insulated container of the embodiment can provide an insulated container with excellent thermal insulation and thin walls, as well as a spinal magnetometer using it.

[0251] This invention can be implemented in various ways and with different modifications without departing from the broad spirit and scope of the invention. Furthermore, the above-described embodiments are illustrative of the invention and do not limit its scope. That is, the scope of the invention is defined not by the embodiments, but by the claims. Moreover, various modifications implemented within the scope of the claims and their equivalents are considered to be within the scope of the invention.

[0252] This application is based on Japanese Patent Application No. 2021-090086, filed on May 28, 2021. The description, claims, and drawings of Japanese Patent Application No. 2021-090086 are incorporated herein by reference.

[0253] Explanation of reference numerals in the attached figures

[0254] 10. Insulated containers

[0255] 11. Inner container

[0256] 12 Refrigerant injection pipe,

[0257] 13 cylindrical containers,

[0258] 131 upper surface,

[0259] 122, 132 cylindrical part,

[0260] 123, 133 Bottom surface

[0261] 132O outer layer

[0262] 132I inner layer,

[0263] 111, 112 Specified areas

[0264] 101. Measured object,

[0265] 102 Measuring device

[0266] 14. Outer container

[0267] 15. Gaps,

[0268] 16. Refrigerant

[0269] 17. Superconducting quantum interference device

[0270] 18. Organisms

[0271] 19. Measuring surface

[0272] 21. Substrate

[0273] 22 Second cylindrical container,

[0274] Containment Departments 23 & 24

[0275] 60 spinal magnetometers

[0276] 63, 64 Fabrics

[0277] 65. Fixing wire

[0278] 66 Flat filaments

[0279] 70, 71 honeycomb panels.

Claims

1. An insulated container comprising an inner container and an outer container surrounding the inner container through a gap. The inner container and the outer container are made of fiber-reinforced plastic impregnated with resin in a fiber-containing substrate. The inner container includes a cylindrical container and a second cylindrical container, each having a receiving portion for storing refrigerant inside, and a refrigerant injection pipe for injecting refrigerant into the cylindrical container. The receiving portion of the second cylindrical container is in communication with the receiving portion of the first cylindrical container. The substrate constituting the defined area of ​​the second cylindrical container and the defined area of ​​the outer container comprises fabric. The designated area of ​​the outer container further includes a honeycomb sheet, on which the fabric is laminated on one and the other sides. The fabric is composed of at least one selected from the group consisting of glass fiber, alumina fiber, and carbon fiber, and the honeycomb sheet is composed of at least one selected from the group consisting of aramid honeycomb sheet, paper honeycomb sheet, and non-combustible honeycomb sheet. The insulated container is used in a spinal magnetometer equipped with a superconducting quantum interference device that detects magnetic fields generated by living organisms. The superconducting quantum interference device is immersed in a refrigerant stored in the containment portion of the second cylindrical container, and the measurement surface of the superconducting quantum interference device is opposite to the designated area of ​​the second cylindrical container and the designated area of ​​the outer container.

2. The heat-insulating container as described in claim 1, wherein, The substrate constituting the designated area of ​​the outer container further comprises a unidirectional fiber sheet formed by multiple fibers twisted together in one direction, and the unidirectional fiber sheet is stacked on at least one of the two sides of the honeycomb sheet.

3. The heat-insulating container as described in claim 2, wherein, The fibers of the unidirectional fiber sheet constituting the defined area of ​​the outer container are parallel to the extending direction of the core of the second cylindrical container.

4. The heat-insulating container as described in claim 2 or 3, wherein, The substrate constituting the designated area of ​​the second cylindrical container further comprises a unidirectional fiber sheet formed by multiple fibers unidirectionally twisted together.

5. The heat-insulating container as described in claim 4, wherein, The fibers of the unidirectional fiber sheet constituting the defined region of the second cylindrical container are orthogonal to the extension direction of the core of the second cylindrical container.

6. The heat-insulating container as described in claim 4, wherein, With the unidirectional fiber sheet constituting the designated area of ​​the outer container facing the unidirectional fiber sheet constituting the designated area of ​​the second cylindrical container, the outer container surrounds the second cylindrical container.

7. The heat-insulating container as described in claim 2 or 3, wherein, The unidirectional fiber sheet constituting the defined area of ​​the outer container is composed of at least one selected from the group consisting of glass fiber, alumina fiber, and carbon fiber.

8. The heat-insulating container as claimed in claim 4, wherein, The unidirectional fiber sheet constituting the defined region of the second cylindrical container is composed of at least one selected from the group consisting of glass fiber, alumina fiber, and carbon fiber.

9. The insulated container as described in any one of claims 1 to 3, wherein, The thickness of the honeycomb sheet is 1 to 7 mm.

10. The heat-insulating container as described in any one of claims 1 to 3, wherein, The resin includes epoxy resin.

11. A spinal magnetometer, which has the following features: A superconducting quantum interference device for detecting magnetic fields generated by living organisms; and The heat-insulating container according to any one of claims 1 to 10, The superconducting quantum interference device is immersed in the refrigerant stored in the containment section of the second cylindrical container.

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