JP2018006601A - Insulating tape for high-temperature superconductive wire material, high-temperature superconductive wire material, and high-temperature superconducting coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an insulating tape for a high-temperature superconductive wire material, which has flexibility, achieves good workability, and has high thermal conductivity; a high-temperature superconductive wire material arranged by use of the insulating tape; and a high-temperature superconducting coil superior in stability.SOLUTION: An insulating tape for a high-temperature superconductive wire material is 1.5 W/mK or more in thermal conductivity in at least one direction at 77 K, and is composed of a film of an organic polymer represented by the general formula (Chem.1). The insulating tape is used as an insulator to obtain a high-temperature superconductive wire material and a high-temperature superconducting coil superior in stability. The organic polymer includes, as a repeating unit, a benzazole ring represented by (Chem.1). In the general formula (Chem.1), "n" is a real number of 0 to 1, "X" represents S atom, O atom or NH group, "Y" represents at least one kind selected from a phenylene group, a biphenylene group and a naphthalene group, provided that it may include them in an appropriate proportion, and "R" represents at least one kind selected from a halogen atom, and an alkyl group with C1-C6.SELECTED DRAWING: None

Description

  The present invention relates to an insulating tape for a high-temperature superconducting wire composed of an electrically insulating high thermal conductive organic polymer sheet material, a high-stability high-temperature superconducting wire using the same, and a high-temperature excellent in stability composed of the high-temperature superconducting wire. The present invention relates to a superconducting coil.

  Oxide superconductors mainly composed of bismuth-based oxides and yttrium-based oxides have a higher superconducting transition temperature than metal-based superconductors. For this reason, metal superconducting materials that could not be used without cooling to the liquid helium temperature are called high-temperature superconductors, and are expected as an elemental technology of AC superconducting technology that has been difficult to put into practical use. However, these oxide superconductors called high-temperature superconductivity have significantly low thermal conductivity, so improvement in cooling efficiency and removal of AC loss heat are important issues in application development.

  In particular, in a coil using an oxide superconducting wire, a slight amount of heat generated during energization is accumulated, which causes a rapid temperature rise, which not only loses the superconducting function, but also may cause thermal deterioration of the superconducting wire. This is called “thermal runaway” and is the most important problem that must be solved for practical use in the field of high-temperature superconductivity. (Patent Document 1, Non-Patent Document 1)

   As a means of solving the thermal runaway problem, there is a method of depriving the heat from the parts in contact with the high temperature superconducting wire. That is, a high temperature superconducting coil with a heat dissipation material is produced. Examples of the parts that come into contact with the high-temperature superconducting wire in the high-temperature superconducting coil include an insulating tape, a coil bobbin, and a spacer.

Polyimide is generally used as an insulating tape material, but since the thermal conductivity is low, the heat removal effect is low, and it cannot be expected to solve the thermal runaway problem. High heat conductivity materials are required as heat removal materials. Generally, metals such as aluminum and copper have high thermal conductivity, but these metals are conductive and require high insulation. It cannot be used directly on parts that come into contact with superconducting wires (Patent Document 2).

  When considering the heat removal from the parts in contact with the high-temperature superconducting wire in the high-temperature superconducting coil, these must be electrically insulating materials. Therefore, an electrically insulating high heat conductive material is necessary.

Examples of highly heat conductive materials having excellent insulating properties include some ceramics such as ticker aluminum and boron nitride. However, these are fragile and difficult to handle because of poor processability, and are not suitable for insulating tapes that require flexibility (Patent Document 1).

  Examples of the high thermal conductive insulating parts include coil bobbins and spacers other than the insulating tape, and these do not require flexibility. However, since the above-mentioned ceramic high thermal conductive material has poor workability, it cannot be applied to a bobbin having a complicated shape. Hard and brittle ceramics are not applicable because they are likely to damage the high-temperature superconducting material.

Examples of the superconducting coil bobbin having high thermal conductivity and electrical insulation and the spacer material include high strength and high thermal conductivity polymer fiber reinforced composite materials. For example, ultrahigh molecular weight polyethylene and PBO fibers are known as organic fibers having excellent insulating properties and high thermal conductivity (Patent Documents 3 and 4, Non-Patent Documents 1 and 2).
Ultra-high molecular weight polyethylene fibers are used for cold bedding because of their high thermal conductivity and high cooling efficiency (Patent Document 5, Non-Patent Document 3). On the other hand, fiber reinforced composite materials using these as reinforcing fibers By doing so, it is also possible to produce a high thermal conductive plastic (Non-patent Document 2). These can be manufactured and used for coil bobbins and spacers for superconducting magnets by molding technology of fiber reinforced composite materials, and their thermal conductivity contributes to the prevention of thermal runaway of superconducting coils. (Patent Documents 1, 6, 7 and Non-Patent Document 1).

  However, heat removal by a coil bobbin, a spacer, or the like largely depends on the shape / structure of the coil, and it is necessary to consider the “heat removal structure” from the coil design stage. Moreover, since the high thermal conductive insulating material using these organic polymer high thermal conductive fibers is excellent in impact resistance, the handling property is superior to that of ceramics (Non-Patent Documents 4 and 5). Since it has high strength, there is a problem that cutting is difficult. That is, the structure and shape of the coil bobbin and spacer that can be manufactured are limited. Therefore, although the heat removal from the high temperature superconducting coil by the coil bobbin / spacer made of the high thermal conductive organic polymer fiber reinforced composite material is recognized, there are limitations on the applicable conditions.

  Next, considering the case where the organic polymer high thermal conductive fiber used for the coil bobbin / spacer described above is used for the insulating tape, it is required to be in the form of a tape in order to carry out electrical insulation. The molecule needs to be subjected to some kind of processing such as making a composite material. However, for example, a method of consolidating a fiber material with a resin to form a sheet and cutting the sheet into a tape is conceivable. However, processing that requires fiber cutting is difficult, and manufacturing costs are high. On the other hand, the fiber / resin may be broken due to bending.

  As described above, there is a demand for an electrical insulating tape made of a single material that is flexible like a polyimide sheet and has high thermal conductivity.

P2001-307915 P2003-166178 P2004-285522 P2004-225170 P2010-236130 P2001-326117 P2014-090089 P2005-330470

Yasuhiko Yamanaka, Tomoaki Takao, Journal of the Textile Society of Japan, 68, no.4, p111-117 (2012) H. Fujishiro et al. (3 others), Japan Journal of Applied Physics, p5633-5637 (1997) Tokuichi Maeda, Journal of the Textile Society of Japan, 68, p184-187 (2012) Yukihiro Nomura, Journal of the Japan Society for Composite Materials, 33, p191-195 (2007) Hiroshi Yasuda, Yasuhiko Yamanaka, Osaka Chemical Marketing Series, 3, p123-133 (1991)

  The present invention is a conventional high-temperature superconducting wire having excellent electrical workability and flexibility, which has high electrical conductivity and high thermal conductivity, in order to enhance the heat dissipation of high-temperature superconductors that could not dissipate AC loss heat due to low thermal conductivity. It is intended to provide a high-temperature superconducting wire and a high-temperature superconducting coil excellent in stability using the insulating tape.

The present invention has been achieved as a result of intensive research to solve the above-described problems, and employs the following configuration. That is,
1. An insulating tape for a high-temperature superconducting wire characterized by comprising an organic polymer film having a thermal conductivity of at least 1.5 W / mK at 77K in at least one direction. The organic polymer is represented by the following general formula (Formula 1) A highly heat-conductive sheet comprising a benzazole ring as a repeating unit. However, in the following general formula (Formula 1), n is a real number of 0 or more and 1 or less, X represents an S, O atom or NH group, and Y is at least 1 selected from a phenylene group, a biphenylene group or a naphthalene group. Seeds, which may be included in any proportion. R is at least one selected from a halogen atom and an alkyl group having 1 to 6 carbon atoms.


2. 2. The insulating tape for high-temperature superconducting wire according to 1, wherein the organic polymer is polyparaphenylene benzobisoxazole. The insulating tape for high-temperature superconducting wires according to 1 or 2, wherein R in the general formula (Formula 1) is a methyl group.
4). A high-temperature superconducting wire comprising the insulating tape for a high-temperature superconducting wire according to any one of 1 to 3.
5. A high-temperature superconducting coil comprising the insulating tape for a high-temperature superconducting wire according to any one of 1 to 3 or the high-temperature superconducting wire according to 4.

The present invention is a high-temperature superconducting wire insulating tape with high heat removal using an organic polymer tape having high thermal conductivity similar to that of a metal and having flexibility and workability similar to polyimide, and thermal runaway by using this. We were able to provide high-temperature superconducting wires and high-temperature superconducting coils that have low probability and can be energized stably.

According to the present invention, it becomes possible to produce a high-temperature superconducting wire insulating tape having high thermal conductivity and excellent workability and flexibility, a high-temperature superconducting wire using the same, and a high-temperature superconducting coil excellent in stability.

FIG. 1 is a schematic view of a high-temperature superconducting wire obtained by winding an insulating tape around an oxide high-temperature superconducting wire. FIG. 2 is a schematic explanatory view of a high-temperature superconducting wire as a joined body of an insulating tape and an oxide superconducting wire. FIG. 3 is a schematic view showing a thermal conductivity measurement method.

The present invention is described in detail below.
The insulating tape for a high-temperature superconducting wire of the present invention comprises at least one organic polymer film having a thermal conductivity of at least one direction at 1.5 K / mK of 77 W, preferably 2.0 W / mK or more, The organic polymer is characterized by containing a benzazole ring represented by the following general formula (Formula 1) as a repeating unit. When the thermal conductivity in at least one direction of the film is less than 1.5 W / mK, the heat removal amount required for the insulating tape for high-temperature superconducting wire is insufficient, and the function cannot be performed. Hereinafter, this sheet is referred to as a heat conductive sheet.

At least one organic polymer film having a thermal conductivity of at least 1.5 W / mK, preferably at least 2.0 W / mK at 77K constituting the insulating tape of the present invention is a high crystallinity. The organic polymer has high orientation and high heat resistance, and examples of the organic polymer include polybenzazole (PBZ) described in the general formula (Chemical Formula 1). It is known that the thermal conductivity of organic polymers greatly depends on crystallinity and molecular chain orientation. This is because the heat conduction of the electrical insulator is due to heat propagation by phonons. Therefore, PBZ, which is a rigid polymer and a liquid crystal polymer, is highly oriented and can exhibit high thermal conductivity that cannot be expressed by other organic polymer films. Examples of polybenzazole include polyparaphenylene benzobisoxazole (PBO), polybenzathiazole (PBZT), and polybenzimidazole (PBI). Alternatively, polymethylparaphenylenebenzobisoxazole having a methyl group on the benzazole ring, and R in the general formula (Chemical Formula 1) as an alkyl group having 1 to 6 carbon atoms such as ethyl group, propyl group, tert-butyl group, or halogen Examples thereof include PBZ having a substituent (side chain) such as a group, but are not limited thereto. The repeating unit Y represented by the general formula (Chemical 1) is preferably a group represented by the following formula (Chemical Formula 2). These may be included in any ratio. The structure and production method of PBZ in the present invention are disclosed in, for example, Patent Document 8, but are not limited thereto.

The insulating tape has a thickness of 1 mm or less, preferably 200 μm or less, and more preferably 50 μm or less. When the sheet thickness exceeds 1 mm, the coil becomes too thick when inserted and used between the wires between the superconducting wires.

  The shape of the insulating tape of the present invention may be a tape having a width of 1 mm or more and 15 mm or less. Further, a tape having a width of 1 m or more may be used. That is, the shape is not particularly limited.

  The insulating tape of the present invention obtains its thermal conductivity with an organic polymer film. Therefore, since mixing of inorganic particles for imparting thermal conductivity, metal plating, and the like are not performed, an insulating tape with excellent flexibility and handleability can be obtained.

  As a kind of the film constituting the insulating tape, an organic polymer may be coated in addition to the heat conducting organic polymer film. Other organic polymers include polyester, nylon, acrylate, urethane, cellulose, polyimide, and the like. The constituent ratio of the high thermal conductive film is preferably 30% or more, more preferably 50% or more in the thickness ratio.

  The high temperature superconducting wire of the present invention comprises an oxide superconducting wire and the above insulating tape.

  The oxide superconducting wire may be a bismuth-based oxide superconductor such as Bi2212 or Bi2223, or an yttrium-based oxide superconductor such as YBCO. The shape of the superconducting wire may be a tape or a wire, but a tape is desirable.

  The high-temperature superconducting wire is a combination of the oxide superconducting wire and the insulating tape. The combination is made by winding the insulating tape around the oxide superconducting wire, and bonding it to the upper or lower surface. There are those that are bonded together including the side surfaces, and any of them may be used. Examples of these combination structures are shown in FIGS.

  The high-temperature superconducting coil in the present invention is a coil using the above-mentioned high-temperature superconducting tape, and means a pancake type coil, a cylindrical coil, a solenoid coil, a substrate evaporation type coil, or the like.

  As the high temperature superconducting wire winding state of the high temperature superconducting coil in the present invention, the oxide superconducting wire is wound while sandwiching the insulating tape between the layers, and as described above, the oxide superconducting wire and the insulating tape have already been wound. Although the thing formed by winding the high temperature superconducting wire formed in combination is mentioned, any of them may be used.

The method for cooling the high-temperature superconducting coil in the present invention may be a direct cooling method using a refrigerant such as liquid nitrogen. Further, an indirect cooling method including a conduction cooling method and a method by thermal contact with the refrigerant layer may be used. Furthermore, a forced cooling method using a conduit tube may be used.
The currents flowing through the high temperature superconducting coil in the present invention are direct current, alternating current, and pulse.

  The polybenzazole having an alkyl group added to the side chain of the present invention is capable of improving the mechanical properties by causing a crosslinking reaction by irradiation with an active energy ray such as an electron beam. By applying this, active energy irradiation is performed with resin coated polybenzazole film with alkyl group added to the side chain, resulting in cross-linking between polybenzazole film and resin component, improving adhesion Can be expected.

   Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are not intended to limit the present invention, and all modifications may be made within the scope of the present invention without departing from the gist of the preceding and following descriptions. Is done. In addition, the measuring method of each characteristic value is as follows.

The experimental method used in the present invention is shown below.
(experimental method)

(1) Measurement of Intrinsic Viscosity The viscosity of a polymer solution prepared to a concentration of 0.5 g / l using methanesulfonic acid as a solvent was measured and calculated using a Ostwald viscometer in a 25 ° C. constant temperature bath.

(2) Measurement of thermal conductivity Thermal conductivity was measured by a steady heat flow method using a system (Fig. 3) with a temperature controller with a helium refrigerator. In the case of a film sample, 20 sheets cut to a sample length of about 25 mm and a width of 5 mm were bonded. Stycast GT was used for fixing the sample stage. An Au-chromel thermocouple was used for temperature measurement. A 1 kΩ resistor was used for the heater, and this was adhered to the end of the sample with varnish. The measurement temperature range was 27 ° C. The measurement was performed in a vacuum of 10 ⁻³ Pa in order to maintain heat insulation. The measurement was started after 24 hours had elapsed in a vacuum state of 10 ⁻³ Pa to make the sample dry. The thermal conductivity was measured by passing a constant current through the heater so that the temperature difference ΔT between the two points L was 1K. This is shown in FIG. Here, the thermal conductivity e obtained when the cross-sectional area of the sample is S, the distance between the thermocouples by the L heater is Q, and the temperature difference between the thermocouples is ΔT is e (W / mK) = (Q / ΔT) (L / S).

(3) Flexibility of tape (bending resistance)
Bend the sample film at a right angle and put it back. After repeating this operation 10 times, the thermal conductivity in the direction perpendicular to the fold line was measured by the method described in 1 above, and the ratio with the thermal conductivity before folding was determined.

(4) The cutting ability of the tape was observed to determine whether or not it could be cut by a paper stationery. Using a new paperwork stationery jar, cut 10cm long 50 times, and the first and 50th cuts are as follows: No fluff (good cutting condition: ○), fluff present (△), uncut (× ).

(5) Manufacturing Method of High-Temperature Superconducting Coil A high-temperature superconducting coil was manufactured using a Bi2223 high-temperature superconducting tape wire having a width of 4 mm and a thickness of 0.15 mm according to the following example. Table 1 shows the manufactured coil specifications.

(6) Evaluation Method for High-Temperature Superconducting Coil The produced high-temperature superconducting coil was cooled to 70K using a GM20K refrigerator, subjected to alternating current at 60 Hz, and measured for stability.

Examples are shown below.
(Example 1)
In a nitrogen stream, 7.097 g of terephthalic acid, 9.147 g of 4,6-diaminoresorcin dihydrochloride, and 13.608 g of phosphorus pentoxide are mixed with 44.71 g of 116% polyphosphoric acid, and the mixture is stirred and mixed at 70 ° C. for 15 minutes. did. The temperature was further raised to 120 ° C., stirred and mixed for 3.5 hours, dehydrochlorination was performed, the temperature was raised to 135 ° C. and stirred for 16 hours, and oligomerized. Then, it heated up at 200 degreeC and superposed | polymerized and obtained the PBO polymer dope. Intrinsic viscosity was 40 dL / g. The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours, extracted with phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 4 hours. The obtained film had a thickness of 25 μm. From this, 2500 pieces of tape 4mm wide and 1m long were cut out. The tape was wound around a high-temperature superconducting tape wire (Bi2223) shown in the coil specifications in Table 1 at an angle of 45 ° to produce a superconducting coil tape wire insulated from the surroundings. Using this, the pancake type high temperature superconducting coil shown in Table 1 was produced.

(Example 2)
6.9 g of 4,6-diaminoresorcin dihydrochloride, 0.6 g of 2-methyl-4,6-diaminoresorcin dihydrochloride, 0.6 g of terephthalic acid, 5 g 8.1 g of phosphorus oxide was added, and the mixture was stirred and mixed at 70 ° C. for 15 minutes in the reactor. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 16 hours to oligomerize. Thereafter, the temperature was raised to 200 ° C. to polymerize to obtain a PBO polymer dope in which 10 mol% of a methyl group-substituted benzazole ring was copolymerized. The color of the polymer dope was yellow and the intrinsic viscosity was 21 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 25 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 3)
116% polyphosphoric acid 27.1 g under nitrogen stream, 4,6-diaminoresorcinol dihydrochloride 3.8 g, 2-methyl-4,6-diaminoresorcinol dihydrochloride 1.7 g, terephthalic acid 4.2 g and five 8.0 g of phosphorus oxide was added, and the mixture was stirred and mixed at 70 ° C. for 15 minutes in the reactor. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 19 hours to oligomerize. Then, it heated up at 200 degreeC and superposed | polymerized and the PBO polymer dope by which 30 mol% of methyl group substituted benzazole rings were copolymerized was obtained. The color of the polymer dope was yellow and the intrinsic viscosity was 21 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 36 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

Example 4
In 27.2 g of 116% polyphosphoric acid, 2.7 g of 4,6-diaminoresorcin dihydrochloride, 2.8 g of 2-methyl-4,6-diaminoresorcin dihydrochloride, 4.1 g of terephthalic acid and five 7.9 g of phosphorus oxide was added, and the mixture was stirred and mixed at 70 ° C. for 15 minutes in the reactor. The temperature was further raised to 120 ° C., stirred and mixed for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 20 hours to oligomerize. Thereafter, the temperature was raised to 200 ° C. to polymerize to obtain a PBO polymer dope in which 50 mol% of a methyl group-substituted benzazole ring was copolymerized. The color of the polymer dope was yellow and the intrinsic viscosity was 22 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 60 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 5)
116% polyphosphoric acid 27.3 g under nitrogen flow, 1.6 g of 4,6-diaminoresorcin dihydrochloride, 3.9 g of 2-methyl-4,6-diaminoresorcin dihydrochloride, 4.1 g of terephthalic acid and five 7.8 g of phosphorus oxide was added, and the mixture was stirred and mixed at 70 ° C. for 15 minutes in the reactor. The temperature was further raised to 120 ° C., mixed with stirring for 3.5 hours, dehydrochlorination was performed, and the temperature was raised to 135 ° C. and stirred for 24 hours to oligomerize. Thereafter, the temperature was raised to 200 ° C. for polymerization to obtain a PBO polymer dope in which 70 mol% of a methyl group-substituted benzazole ring was copolymerized. The color of the polymer dope was yellow and the intrinsic viscosity was 20 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 25 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 6)
Under nitrogen flow, 5.5 g of 2-methyl-4,6-diaminoresorcin dihydrochloride, 4.0 g of terephthalic acid and 7.6 g of phosphorus pentoxide were added to 27.5 g of 116% polyphosphoric acid. Stir and mix at 15 ° C. for 15 minutes. The temperature was further raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 30 hours to oligomerize. Then, it heated up at 200 degreeC and superposed | polymerized and obtained the PBO polymer dope. The color of the polymer dope was yellow and the intrinsic viscosity was 18 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 47 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 7)
116% polyphosphoric acid, 27.4 g, under nitrogen flow, 3.7 g of 4,6-diaminoresorcin dihydrochloride, 1.8 g of 2-chloro-4,6-diaminoresorcin dihydrochloride, 4.1 g of terephthalic acid and five 7.7 g of phosphorus oxide was added, and the mixture was stirred and mixed at 70 ° C. for 15 minutes in the reactor. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 16 hours to oligomerize. Thereafter, the temperature was raised to 200 ° C. and polymerization was performed to obtain a PBO polymer dope in which 30 mol% of a chlorine-substituted benzazole ring was copolymerized. The color of the polymer dope was yellow and the intrinsic viscosity was 20 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 25 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 8)
116% polyphosphoric acid 27.3 g under nitrogen flow 3.7 g 4,6-diaminoresorcin dihydrochloride 1.8 g 2-ethyl-4,6-diaminoresorcin dihydrochloride 4.1 g terephthalic acid and five 7.8 g of phosphorus oxide was added, and the mixture was stirred and mixed at 70 ° C. for 15 minutes in the reactor. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 16 hours to oligomerize. Thereafter, the temperature was raised to 200 ° C. to polymerize to obtain a PBO polymer dope in which 30 mol% of an ethyl group-substituted benzazole ring was copolymerized. The color of the polymer dope was yellow and the intrinsic viscosity was 23 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 23 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

Example 9
116% polyphosphoric acid 29.9 g under nitrogen flow, 4,6-diaminoresorcinol dihydrochloride 2.9 g, 2-methyl-4,6-diaminoresorcinol dihydrochloride 1.3 g, 4,4′-biphenyldicarboxylic acid The acid 4.6g and the phosphorus pentoxide 5.6g were added, and it stirred and mixed in the reactor at 70 degreeC for 15 minutes. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 16 hours to oligomerize. Then, it heated up at 200 degreeC and superposed | polymerized and the PBO polymer dope by which 30 mol% of methyl group substituted benzazole rings were copolymerized was obtained. The color of the polymer dope was yellow and the intrinsic viscosity was 22 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 25 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 10)
116% polyphosphoric acid 29.1 g under nitrogen flow, 4,6-diaminoresorcinic dihydrochloride 3.1 g, 2-methyl-4,6-diaminoresorcinic dihydrochloride 1.4 g, 2,6-naphthalenedicarboxylic acid 4.5 g and 6.3 g of phosphorus pentoxide were added, and the mixture was stirred and mixed in the reactor at 70 ° C. for 15 minutes. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 16 hours to oligomerize. Then, it heated up at 200 degreeC and superposed | polymerized and the PBO polymer dope by which 30 mol% of methyl group substituted benzazole rings were copolymerized was obtained. The color of the polymer dope was yellow and the intrinsic viscosity was 22 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 60 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 11)
116% polyphosphoric acid 28.5 g, 1,3-dimercapto-4,6-diaminobenzene dihydrochloride 3.8 g, 1,3-dimercapto-2-methyl-4,6-diaminobenzene dihydrochloride under nitrogen flow 1.7 g of salt, 3.7 g of terephthalic acid and 6.7 g of phosphorus pentoxide were added, and the mixture was stirred and mixed at 70 ° C. for 15 minutes in the reactor. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 16 hours to oligomerize. Thereafter, the temperature was raised to 200 ° C. for polymerization to obtain a PBZT polymer dope in which 30 mol% of a methyl group-substituted benzazole ring was copolymerized. The color of the polymer dope was yellow and the intrinsic viscosity was 21 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 25 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 12)
116% polyphosphoric acid 27.0 g under nitrogen flow, 1,2,4,5-tetraaminobenzene tetrahydrochloride 5.1 g, 3-methyl-1,2,4,5-tetraaminobenzene tetrahydrochloride 2 .3 g, 4.2 g of terephthalic acid and 8.1 g of phosphorus pentoxide were added and stirred and mixed in the reactor at 70 ° C. for 15 minutes. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 16 hours to oligomerize. Thereafter, the temperature was raised to 200 ° C. for polymerization to obtain a PBI polymer dope in which 30 mol% of a methyl group-substituted benzazole ring was copolymerized. The color of the polymer dope was yellow and the intrinsic viscosity was 21 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 23 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Example 13)
116% polyphosphoric acid 27.1 g under nitrogen stream, 4,6-diaminoresorcinol dihydrochloride 3.8 g, 2-methyl-4,6-diaminoresorcinol dihydrochloride 1.7 g, terephthalic acid 4.2 g and five 8.0 g of phosphorus oxide was added, and the mixture was stirred and mixed at 70 ° C. for 15 minutes in the reactor. Further, the temperature was raised to 120 ° C., mixed with stirring for 3.5 hours to remove hydrochloric acid, heated to 135 ° C. and stirred for 16 hours to oligomerize. Then, it heated up at 200 degreeC and superposed | polymerized and the PBO polymer dope by which 30 mol% of methyl group substituted benzazole rings were copolymerized was obtained. The color of the polymer dope was yellow and the intrinsic viscosity was 21 dL / g.
The obtained dope was sandwiched between polytetrafluoroethylene sheets and pressed with a heat press machine at a press plate temperature of 170 ° C. and a pressure of 150 kgf / cm ² . The taken-out dope sheet was peeled off from the polytetrafluoroethylene sheet, immersed in 1000 ml of distilled water for 15 hours to extract phosphoric acid, fixed on a metal frame having a side of 1 m, and dried at 80 ° C. for 1 hour. The obtained film had a thickness of 53 μm. Thereafter, a pancake type high temperature superconducting coil was produced in the same manner as in Example 1.

(Comparative example)
A comparative example is shown below.

(Comparative Example 1)
An insulating tape having a width of 4 mm was produced using a polypropylene film (thickness 60 μm). The tape was wound around a high-temperature superconducting tape wire (Bi2223) shown in the coil specifications in Table 1 at an angle of 45 ° to produce a superconducting coil tape wire insulated from the surroundings. Using this, the pancake type high temperature superconducting coil shown in Table 1 was produced.

(Comparative Example 2)
An insulating tape having a width of 4 mm was prepared using a polyimide film (thickness 60 μm). Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1.

(Comparative Example 3)
An insulating tape having a width of 4 mm was prepared using a polyamideimide film (thickness 25 μm). Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1.

(Comparative Example 4)
An insulating tape having a width of 4 mm was prepared using polyethylene terephthalate (thickness: 60 μm). Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1.

(Comparative Example 5)
An insulating tape having a width of 4 mm was prepared using nylon 66 (thickness: 35 μm). Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1.

(Comparative Example 6)
An insulating tape having a width of 4 mm was prepared using a polyethylene film (thickness: 23 μm). Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1.

(Comparative Example 7)
Epoxy resin (Mitsubishi Chemical Epicoat 827 / Hitachi Kasei HN5500 / Mitsubishi) on a piece of plain weave with 1320 dtex yarns made of high-strength polyethylene fibers (Toyobo, Izanas, SK-60) arranged vertically / laterally at 15 pieces / inch each. Chemical impomate BMI23 = 100/85/1 (weight ratio)) was press molded at 120 ° C. for 5 hours to obtain a sheet of 1 m × 1 m and a thickness of 290 μm. From this, 2500 pieces of tape 4mm wide and 1m long were cut out. Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1.

(Comparative Example 8)
Epoxy resin (Mitsubishi Chemical Epicoat 827 / Hitachi Kasei HN5500 / Mitsubishi Chemical) one plain weave fabric with 165 dtex yarns made of high-strength polyethylene fibers (Toyobo, Izanas, SK-60) arranged vertically / horizontally 60 per inch Epomate BMI23 = 100/85/1 (weight ratio)) and press-molded at 120 ° C. for 5 hours to obtain a sheet of 1 m × 1 m and a thickness of 170 μm. From this, 2500 pieces of tape 4mm wide and 1m long were cut out. Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1.

(Comparative Example 9)
Epoxy resin (Mitsubishi Chemical Epicoat 827 / Hitachi Kasei HN5500 / Mitsubishi Chemical Epomate BMI23 = 100) on a plain woven fabric with 545 dtex yarns made of high-strength PBO fibers (Toyobo, Zylon HM) arranged in length / width 33 / inch each / 85/1 (weight ratio)) and press-molded at 120 ° C. for 5 hours to obtain a sheet of 1 m × 1 m and a thickness of 190 μm. From this, 2500 pieces of tape 4mm wide and 1m long were cut out. Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1.

(Comparative Example 10)
Chikka aluminum particles (Tokuyama, H grade, particle size 1 μm) were mixed in polyimide to obtain a sheet having a thickness of 100 μm and 1 m × 1 m. From this, 2500 pieces of tape 4mm wide and 1m long were cut out. Thereafter, a pancake type high-temperature superconducting coil was produced in the same manner as in Comparative Example 1. The mixing ratio of ticker aluminum / polyimide was 20/80 (volume ratio).
The above evaluation results are shown in Table 2.

INDUSTRIAL APPLICABILITY The present invention can be usefully used as an insulating tape for high temperature superconducting wires having high heat conductivity and excellent flexibility, a high temperature superconducting wire using the same, and a high temperature superconducting coil having excellent stability.

(1) High-temperature superconducting wire (2) Insulating tape (3) Cooling head (4) Oxygen-free copper sample stage (5) Thermocouple thermometer (6) Sample (7) Adhesive (8) Heater (9) Measuring distance: L

Claims (5)

An insulating tape for a high-temperature superconducting wire characterized by comprising an organic polymer film having a thermal conductivity of at least 1.5 W / mK at 77K in at least one direction. The organic polymer is represented by the following general formula (Formula 1) A highly heat-conductive sheet comprising a benzazole ring as a repeating unit. However, in the following general formula (Formula 1), n is a real number of 0 or more and 1 or less, X represents an S, O atom or NH group, and Y is at least 1 selected from a phenylene group, a biphenylene group or a naphthalene group. Seeds, which may be included in any proportion. R is at least one selected from a halogen atom and an alkyl group having 1 to 6 carbon atoms.

2. The insulating tape for high-temperature superconducting wire according to claim 1, wherein the organic polymer is polyparaphenylene benzobisoxazole. The insulating tape for high-temperature superconducting wire according to claim 1, wherein R in the general formula (Formula 1) is a methyl group. A high-temperature superconducting wire comprising the insulating tape for a high-temperature superconducting wire according to any one of claims 1 to 3. 5. A high-temperature superconducting coil comprising the insulating tape for a high-temperature superconducting wire according to any one of claims 1 to 3 or the high-temperature superconducting wire according to claim 4.