JPS62268009A - Reaction-free superconductor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of an unreacted superconducting wire having an inorganic insulation breakdown.

(Prior art) Compound superconducting wires are made of Nb, Sn, V, (:ra, Nb
It is a superconducting wire in which a large number of superconducting compounds such as +AA exist in a matrix metal such as Cu or Al via partitions such as Nb or Ta and partitions such as Co or AZ. However, the surface of the compound superconducting wire used as a lever must be electrically insulated.

The insulation that has been commonly used in the past is one in which copper oxide (2) is provided on the metal surface of an unreacted superconducting wire (1) as shown in FIG. 5(a), and an unreacted superconducting wire (2) as shown in FIG. 1) with a glass braid (3) on the metal surface, and (C) with 5LOf, B+ O on the metal surface of the unreacted superconducting wire (1).
+, PbO,! Oxide powder such as 40゜Ayph (4)
There are some that have .

However, the above (2L) has a thin oxide film of about 1 μm and decomposes in vacuum when heated to a high temperature. Regarding (b), it has poor adhesion to the metal surface and becomes soft and deformed when heated to high temperatures. Furthermore, (C) K had drawbacks such as poor adhesion to the metal surface, peeling off from the conductor surface after coating and drying, and falling off during bending.

Organic insulating coatings have also been considered, but none of them have been satisfactory, as they have drawbacks such as being unable to withstand high-temperature heating.

(Problem to be solved by the invention) As a result of various studies on the above mass production, we found that Nb, Sn, V
sC? Regarding the insulating coating provided on the unreacted training conductor wire before the above-mentioned compound generation heat treatment such as L, Nb5At, etc. (2L
) The coating thickness can be easily controlled within the range of 10 to 100 μm. (b) It has flexibility of 0.5% or more at maximum bending strain rate at room temperature. (C) Compound generation heat treatment 500
Even when heated to ~800°C, the electrical insulation properties do not deteriorate due to dimensions or coating falling off. (cl) Good wettability with organic resins such as epoxy after (c). It was found that it is necessary to satisfy the following characteristics.

(Means for Solving the Problems) The present invention solves the above problems, and the metal surface of the unreacted superconducting wire is made of one of gel-like silanol, titanate, and aluminate having hydrolyzable groups (OH), or 2
This is an unreacted superconducting wire characterized by being covered with more than one species. Here, the present invention provides Zr0t, N1tO snow, T
ID! It contains metal oxides such as 31mN4, BN, SIC, etc., nitrides, borides, and carbohydrates, and furthermore, the metal surface of the unreacted superconducting wire is thin. It may be covered with a metal oxide layer.

The unreacted superconducting wire of the present invention refers to an unreacted superconducting wire that has not been subjected to compound generation treatment, that is, no compounds have been generated. In many cases, the superconducting wire is sold and the user performs the above-mentioned compound-forming heat treatment after forming it into a coil, so the present invention targets the unreacted superconducting wire. However, the subsequent heat treatment for compound formation causes no deterioration in properties and no change in composition.

Therefore, the unreacted superconducting wire of the present invention includes those that have been subjected to subsequent compound heat treatment.

The basic structure of the inorganic insulating film of the present invention is to form a film of one or more types of 7ranol, titanate, aluminate, etc. on the metal surface of an unreacted superconducting wire.
As shown in Figure (b), the feature is that the metal surface of the unreacted superconducting wire is linked to the 81, T1, and Ae groups based on -OH groups, and the conventional method consists of oxide or oxide powder on the metal surface. This is fundamentally different.

However, the concentration of the above-mentioned silanol, titanate, aluminate, etc. is preferably from 0.5 to 5% by weight, and if it is less than this range, the insulation effect will be weak, and if it exceeds this range, the coating will peel off. Therefore, even if a plurality of layers are formed within this range, the same effect can be obtained.

In addition, metal oxides such as ZrO*, AltO1%T10. A similar effect can be obtained by adding nitrides such as Sl, N, BN, SiC, etc. by weight of 995 to 95%. However, a thin metal oxide layer is formed on the surface of the unreacted superconducting wire during the normal manufacturing process, but in order to increase the adhesion of silanol, etc., the surface of the unreacted superconducting wire is coated with a metal oxide layer in advance. Good results can be obtained by forming layers.

(Example 1) As shown in Fig. 1, an unreacted superconducting wire (1) with a copper surface and an outer diameter of 0.7 wm, which has many Nb5Sn superconducting wires, is oxidized black in an alkaline solution to form 5i (CCHs). )
The resulting unreacted superconducting wire was passed through a solution containing +4.5%, HtO, and CH, OH as main components, and then passed through a drying oven at 1120°C and dried to form an insulating coating (5). The wire diameter is 0.70 mm. This unreacted superconducting wire is
Line analysis revealed that -si(OH) group was the main component, and 5101 was not detected. That is, 31 (Q
It was found that C)l, )4, HtOlC,H, and OH were hydrolyzed and partially condensed and polymerized. This unreacted superconducting wire was wound around a mandrel and the strain rate was measured. As a result, there was no peeling of the coating up to a maximum strain rate of 12 inches. Furthermore, when this unreacted superconducting wire with an insulating coating was subjected to compound formation heat treatment at 650° C. for 100 hours, the coating did not come off.

(Example 2) As shown in Fig. 1 (2L), an unreacted superconducting wire (1
) was oxidized black in an alkaline solution, and then passed through an aqueous solution containing 60% by weight of ZrOt to form a film with a thickness of about 20 μm on the surface. Then, it was dried by passing it through a 100°C oven. This was passed through a solution containing 5i(OCHs) + 1%, HtO and CH,OH as main components, and then 70
The insulating coating (
The wire diameter of the unreacted superconducting wire obtained in 5) was 0.75 m.
+n. When this unreacted superconducting wire was analyzed by X-rays, Zr0t (6) and -3i(OH)li groups (5) were the main components, and 5ins was not detected. That is, 5i (OCHI) 1, H 0. It was found that CH and OH were hydrolyzed and partially condensed.

As a result of winding the obtained unreacted superconducting wire around a mandrel and measuring the strain rate, no peeling of the coating was observed until the maximum strain rate was 1.47%.

Furthermore, this unreacted superconducting wire with an insulating coating was heated at 700℃ for 72 hours.
As a result of the heat treatment for time compound generation, no peeling of the film was observed.

Similar results were obtained when titanate-based isopropyl triisostearoyl titanate and aluminate-based acetalkoxyaluminum diisopropylate were used in place of the silanol group -3l (CI() t) in the above examples.

As a conventional example for comparison, as shown in Fig. 5 (2L), a copper oxide ( 2)
As in Example 1, there was no edge of 700 mm.

(Effects) According to the present invention, the coating thickness can be easily controlled in the range of 10 to 100 μm, has flexibility with a maximum bending strain factor of 0.5 at room temperature, and has It is possible to obtain an unreacted superconducting wire in which the coating does not fall off and the characteristics do not deteriorate even when heated to 800°C.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an unreacted superconducting wire showing an embodiment of the present invention. FIG. 2(,) is a vertical cross-sectional view of an unreacted superconducting wire showing another embodiment of the present invention, and FIG. 2(b) is a schematic diagram of the insulating coating of the present invention. 1... Unreacted superconducting wire, 2... Copper oxide, U... Glass braid, E... Oxide powder, 5... Silanol, 6... Oxide, Applicant: Furukawa Electric Co., Ltd.
ノ' Figure 1 0-M+-0 (a) (b) Figure 2 (a) (b) (c) 3rd
Illustration procedure amendment (method) & Showa 6
August 21, 1999 Special, Mr. L, Director General of the Pestle Agency, $Okitsu Display, Patent Application No. 1104014, No. 1988, No. 2
Title of the invention: Unreacted superconducting wire telephone 03 (-286) 5545 4 Date of amendment order: July 29, 1985 Contents of amendment: page 9, line 7 of the MB book, “Figure 5 (a), (b), (c) is a cross-sectional view of a conventional unreacted superconducting wire.'' Full insert.

Claims (4)

[Claims] (1) The metal surface of the unreacted superconducting wire has hydrolyzable groups (OH)
An unreacted superconducting wire characterized in that it is covered with one or more of gel-like silanol, titanate, and aluminate. (2) The unreacted superconducting wire according to claim 1, characterized in that a metal oxide such as ZrO_2, Al_2O_3, TiO_2 is contained in gel-like silanol, titanate, or aluminate. (3) The unreacted product according to claim 1, characterized in that nitrides, borides, and carbides such as Si_3N_4, BN, and SiC are contained in the gel-like silanol, titanate, and aluminate. superconducting wire. (4) Claim 1, characterized in that the metal surface of the unreacted superconducting wire is covered in advance with a thin metal oxide layer.
Unreacted superconducting wire as described in section.