CA1298744C - Electric wire - Google Patents
Electric wireInfo
- Publication number
- CA1298744C CA1298744C CA000566490A CA566490A CA1298744C CA 1298744 C CA1298744 C CA 1298744C CA 000566490 A CA000566490 A CA 000566490A CA 566490 A CA566490 A CA 566490A CA 1298744 C CA1298744 C CA 1298744C
- Authority
- CA
- Canada
- Prior art keywords
- electric wire
- film
- solution
- accordance
- gel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
- H01B13/06—Insulating conductors or cables
- H01B13/065—Insulating conductors with lacquers or enamels
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
- H01B3/10—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances metallic oxides
- H01B3/105—Wires with oxides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/28—Protection against damage caused by moisture, corrosion, chemical attack or weather
- H01B7/2806—Protection against damage caused by corrosion
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/29—Protection against damage caused by extremes of temperature or by flame
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/29—Protection against damage caused by extremes of temperature or by flame
- H01B7/292—Protection against damage caused by extremes of temperature or by flame using material resistant to heat
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/29—Protection against damage caused by extremes of temperature or by flame
- H01B7/295—Protection against damage caused by extremes of temperature or by flame using material resistant to flame
Abstract
ABSTRACT OF THE DISCLOSURE
An electric wire has coating of a gel film which is formed by applying a solution obtained by hydrolyzing and dehydrating/condensing alkoxide onto-an outer part of a conductor and thereafter leaving the same.
An electric wire has coating of a gel film which is formed by applying a solution obtained by hydrolyzing and dehydrating/condensing alkoxide onto-an outer part of a conductor and thereafter leaving the same.
Description
lZ987q~4 TITLE OF THE I~VEN~I ~N
Electric Wire BACKGROUND OF THE IN~7ENTION
Field of the.Invention The prcsent invention relates to an electric wire, and more particularly, it relates to an electric wire which is applied to an electric.wire requiring.fire resistance and heat resistance such as a magnet wire or a wire employed in the vicinity of-a nuclear.reactor, or a special wire or cable requiring corrosion resistance.
Description of the-Prior Art The aforementioned electric wire requiring.heat resistance or corrosion resistance..is-generally prepa.r.ed by a covered conductor, which is coated with organic material. However, an organic coa.ting film is insufficient in long-term stability, heat resistance., chemical durability and the like.
Thus, there has been provided a conductor coated with a compound of metal or metalloid, which.is different from the material for the conductor, in order to attain heat resistance and corrosion resistance. For example, National Patent Publication Gazette No. 501783/1985 in the name.of Raychem Inc., published in Japan on Octo~er 17, 1985, discloses a conductor which is coated with an oxide or a nitride by vacuum deposition, in order to provide q~
lZ~
heat resistance to an elec~ric wire to be utilized under a high temperature. A compound for forming such coating is prepared by an oxide or a nitride of aluminum, silicon e~c. Since such oxide is excellent in heat resistance and corrosion resistance, an electric wire coated with the oxide can be provided with high heat resistance and corrosion resistance.
The aforementioned electric wire which is covered with a ceramic film has been studied for improving these characteristics. Such a ceramic film is formed by:
(a) a method of forming a film from a vapor phase (vapor phase thin film growth method), such-as CVD
(chemical vapor deposition), PVD (physical vapor deposition) or flame coating;
(b) an electrochemical method of forming a film in a solution, such as plating;
(c) a sol-gel method of forming a film from a li~uid phase by chemical reaction of reacting alkoxide; or Id) a method of forming a film by dipping in a melt.
As hereinabove described, it i5 well known that an oxide of ceramics such as A1203 or SiO2 is excellent in heat resistance and corrosion resistance. However, such an oxide formed by vacuum deposition is rather insufficient in adhesion to the material, such as copper, for a conductor. Therefore, when an electric wire coated lZ9879~
with an oxide is used under corrosive environment over a long period of time, for example, the oxide film may partially peel off from the copper surface., to result in corrosion from the exposed portion.
The vapor phase thin film grow~h method such as vacuum deposition is employed as a method of forming.an oxide film on the surface of a conductor. However, a film obtained by vacuum deposition or the like may be inferior in flexibility. Therefore., when a wire coated with an oxide by vacuum deposition is used in a bended state, for example, the oxide film may be broken by stress applied to the surface of the conductor, to result in corrosion from the broken portion.
SUMMAR~ OF THE INVENTION
Accordingly, an object of the present invention is to provide an electric wire which effectuates excellent-heat resistance and corrosion resistance over a long period of time, by forming a film having excellent adhesion.and flexibility. Another object of the present invention is to provide an electric wire which can be industrially obtained by simple means.in a step of coating an elonga.ted wire conductor.
An electric wire in accordance with the present invention comprisRs a conductor and a gel film formed by applying a solution ob.tained by hydrolyzing and lZ~187~
deh~drating/condensillg alkoxide on.o an ou~er ~art of the conductor and leaving the same.
The gel film contributing to heat resistance, which is formed by-a sol-gel method in the present inventionj is excellent in flexibility and adhesion since the same-is left not to be completely changed-into a ceramic state but to remain in a gel state This gel film is changed into a ceramic state by heating, to be improved in heat resistance. However, it has been recogni~ed that its flexibility is reduced as much as it is changed into a ceramic state. On the basis of such a viewpoint of the inventors, the gel film is formed as a main heat resisting layer in the present invention. The conductor is preferably left in an atmosphere-being at a temperature not less than 25C, not more than 400C, in order to form the gel film as a main heat resisting layer.
When the outer surface of a conductor coated with the solution obtained by hydrolyzing and dehydrating/condensing alkoxide and left is oxidized by heat, an oxide thus produced is so fragile that adhesion between the gel film and the conductor surface is lost to cause peeling of the film. In order to prevent this, the conductor surface is preferably plated with Ni or Cr for attaining oxidation resistance, before the same is coated with the solution and left in the aforementioned manner.
~Z9~ 4 Upon heating, the gel film is considerably shrunk to be reduced in thickness. Such shrinkage of the film may result in inferior durability of insulation. While a conductor subjected to low voltage may be simply coated with a gel film alone, a problem is caused in durability of insulation when such a simple coa.ted wire is applied-to a power cable. Therefore, particulates of a metal oxide., a metal nitride or a metal boride are preferably dispersed/mixed-in the.gel film as ceramic filler for suppressing shrinkage.of the gel film.
Although the gel film is considerably flexible in a natural state, such flexibility may be lost when the gel film is heated to be changed into a ceramic state. Even if the electric wire is utilized in a portion-exposed to strong vibration, the film changed into a ceramic state must not peel off from the conductor by cracking.caused.by the strong vibration. Thus, particularly strong adhesion may be required between the gel film and the conductor.
In this case, an adhesion layer may be provided between the gel film and the conductor, or between the gel film and a plating layer formed on the surface of the conductor. The adhesion layer may be prepared by a film completely changed into a ceramic state by applying a solution obtained by hydrolyzing and dehydrating/condensing alkoxide and thereafter heating the lZ~3874~
same. Alternatively, the adhesion layer may be prepared by a ceramic layer formed by CVD, on the basis of such a viewpoint of the inve~tors that a layer formed by CVD is larger in adhesion to a substrate than a gel film.
The inventive wire may be provided with an outermost layer of organic material, in order to improve slipperiness in winding and durability of insulation under the room temperature. In this case-, the particulates of a metal oxide etc. may be~dispersed~mixed in the organic material layer to improve durability of insulation.
Further, the organic material layer may be formed from a solution of organic material, added to which is a solution obtained b~ hydrolyzing and dehydrating/condensing alkoxide with addition of tetraalkylammonium halide to be mixable into the solution of organic material, in order to improve heat resistance.
A gel film in accordance with the present invention may be formed as a multilayer film having two or more layers, in order to improve-heat resistance, corrosion resistance and durability of insulation. In the process of forming the gel film in accordance with the present invention, alkoxide may be hydrolyzed ~y moisture contained in the atmospheric air, without directly adding water to an alkoxide solution.
lZ91~3791~
These and ot'ner objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present-invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION ~F THE DRAWINGS
Figs. lA, lB, lC and lD are sectional views showing electric wires in accordance with the present invention;
and Fig. 2 illustrates an apparatus for performing a heat resistance test on samples of the electric wires in accordance with the present invention.
DESCRIPTION OF THE PREFERRED E~BODIMENTS
Figs, lA to lD are sectional views showing electric wires in accordance with the prese~t invention.
Fig, lA shows an electric wire, which-comprises a conductor 1 of~copper etc, coated with a gel film 2 of one or more layers,- Fig, lB shows an electric wire which comprises a conductor 1, a plating layer 3 of Ni or Cr formed on the suxface thereof, a gel film 2 covering the plating layer 3 and a covering layer 6 of organic material, Fig, lC shows an electric wire which has a gel film 2 and a ceramic film 4 formed under the gel film 2 by CVD to serve as an adhesion layer. Fig. lD shows an electric wire which has a ceramic film 5 formed by a lZ987~
starting raw material of alkoxide, to serve as an adhesion layer. This ceramic film 5 is formed by applying a solution obtained by hydrolyzing and dehydratinglcondensing metal alkoxide and thereafter heating the same.
Samples for a heat resistance test of the aforementioned electric wires embodying the present invention were prepared as follows.: Each of coating solutions-1 to 6, being prepared by the following methods, was applied onto a copper wire of 2.0 mm~ in diameter by a dipping method at a lift-up speed of 1.0 m/min., to form a multilayer film on.the.copper.wire.
Coatinq Solution 1 Tetrabutylorthosilicate ISi(OC4Hg)4], iso~ropyl alcohol ~C3H70H] and water ~H2O] were mixed.in the mole ratio 10:50:40 to obtain.a solution, to which nitric acid was added by 1/100 mol of tetrabutylorthosilicate. Then the solution was stirred at a temperature of 80C for 100 minutes, and thereafter returned to the room temperature.
oatinq Solution 2 Tetraethylorthosilicate [SitOC2H5)4], ethyl alcohol IC2H5OH] and water.lH2O] were mixed.in the mole ratio 3:60:37 to obtain a solution, to which nitric acid was added by 1l100 mol of tetraethylorthosilicate. Then the lZ9~74~
solution was stirred at a temperature o~ 70C for 100 minutes, and thereafter returned to the room temperature~
Coatinq Solution 3 Tetrabutylorthosilicate ISi(OC4Hg)4~, isopropyl alcohol IC3H7OH) and water ~H2O] were mixed in the mole ratio 20:60:20 to obtain a solutionj to which nitric acid was added by 1/100 mol of tetrabutylorthosilicate. Then the solution was stirred at a temperature o~ 80C for 200 minutes, and thereafter returned to the room temperature.
Coating Solution 4 Tetrabutylorthosilicate [Si(OC4H9)4~, isopropyl alcohol IC3H70H] and water IH2O] were mixed in the mole ratio 10:50:40 to obtain a solution of 100 g, to which silicagel by Wako Junyaku (WAXOGEL, C-100) of 30 g was previously added. Then nitric acid was added by 1/100 mol of tetrabutylorthosilicate, and the solution was stirred at a temperature of 80C for 100 minutes, and therea~ter returned to the room temperature.
Coatinq Solution 5 p-xylene 30~ solution of polyimide Coatinq Solution 6 Tetrabutylorthosilicate ISi(OC4Hg)4], isopropyl alcohol [C3H70H] and water ~H2O~ were mixed in the mole ratio 10:50:40 to obtain a solution, to which nitric acid was added by l/100 mol of tetrabutylorthosilicate. Then _ g 12~ 4 the solution was stirred at a temperature of 80C for 100 minutes and.thereafter returned to the room.temperature.
Tetrabutylammonium bromide l(C4H9)4N Br ~ of 20 g was added to the solution of 100 g and stirred with addition of chloroform ICHCl3], to perform extraction.
This extract was decompressed/dried by an evaporator to remove the solvent, thereby to obtain a pale yellow consistent solution lSiO2 polymer]. This SiO2 polymer was mixed into 10 ml of a p-xylene 30% solution of polyimide, which was then stirred under the room temperature.
Each of the coating solutions 1 to 6 was employed for coating, to form a film by the following treatment. Thus, samples A, B, C, D, E and F were obtained by copper.wires having multilayer coating films at least including gel ~ilms, as shown in Tables 1 to 6.
Table 1 (Sample A) 1st Laver 1 2nd Layer 3rd LaYer. 4th Layer SubstanceNi PlatinqGel Gel Gel Coating __ Solution Solution 1 Solution 2 Solution 2 HeaOed at HeaOed at Left at 25C
Treatment__ 280 C for 220 C for for 6 h.
Film 15 min. 15 min.
Thickness 3 2 2.6 20.0 (~m) .
Table 2 (Sample B) _ 1st LaYer 2nd Layer 3rd Layer 4th LaYer-Substance Gel Gel Gel Resin Coating Solution 1 Solution:2 Solution 2 Solution 5 HeaOed atHeaOed at HeaOed at HeaOed at Treatment 280 C for220 C for 170 C for 200 C for 15 min.15 min. 15 min. 30 min.
Film Thickness 2 2.6 11.5 7 (~m) Table 3 (Sample C) .
1st Layer 2nd LaYer 3rd Layer Substance~ Ni Plating Gel Resin Coating Solution __ Solution 1 Solution 5 HeatOed at Hea~ed at Treatment __. 200 C for 200 C for 15 min. 30 min.
Film Thickness 3 5.2 7 (~m) , ,. ~ , .
lZ~l374~
Table 4 (Sample C) ; 1st Layer2nd Layer 3rd Laver SubstanceNi PlatingGel Resin Coating Solution __Solution 4 Solution 5 HeaOed at HeaOed at Treatment__300 C for 200 C for Film 15 min. 30 min.
(~m) 15 Table 5 (Sample E) 1st LaYer 2nd LaYer 3rd Layer SubstanceNi Platin~ Gel Resin Coating Solution _Solution 4 Solution 6 HeaOed at HeaOed at Treatment__ 300 C for 200 C for Film 15 min. 30 min.
(~m) 15 7 - ~2 -lZ9~
Table 6 (Sample F) 1st Layer 2nd Laver 3rd Layer 4th LaYer Substance Ni Platin Ceramics Gel Resin g Coating Solution __ Solution 3 Solution 1 Solution 6 ~eaOed at HeaOed at Heated at Treatment __ 500 C for 200 C for 200C for Film 15 min. 15 min. 30 min.
Thickness ~.3 5.1 Each sample thus obtained was subjected to a heat resistance test as follows:
Heat Resistance Test Insulation Test: As shown in Fig. 2, two samples 7a and 7b were brought into contact with each other to be heated by a heater 12 at à prescribed temperature for 30 minutes with application of voltage of 50 V, thereby to confirm insulating performance.
~ ibration Test: In the insulation test, a motor 15 as shown in Fig. 2 was rotated with a dead weight 16 of 5 g, to apply vibration.
Referring to Fig. 2, numerals 7a and 7b indicate the samples, numeral 8 indicates a quartz plate on which the samples 7a and 7b are placed to be in contact with each lZ~7~4 other, and numeral 9 indicates a quartz pipe for storing the samples 7a and 7b placed on the quartz plate 8, having an end sealed by a closure 10 of silicon rubber and another end blocked by a glass wool member ll. A heater 12 prepared by a tube furnace is provided around the quartz pipe 9, in order to heat the samples 7a and 7b. A
thermocouple 13 is inserted into the quartz pipe 9 through the closure 10, in order to measure the temperatures of the samples 7a and 7b. Numerals 14a and 14b indicate lead wires, which are connected to the-samples 7a and 7b respectively, to be linked to electrodes for the insulation test. The motor 15 is provided on an end of the quartz plate 8 outwardly extending from the quartz pipe 9 through the glass 9 wool member 11, in order to apply vibration to the samples 7a and 7b. The dead weight 16 of 5 g is mounted on the shaft of the motor 15, which is rotated to vibrate the quartz plate 8, thereby to transfer the vibration to the samples 7a and 7b. A
support 17 is provided in order to support the quartz plate 8.
Table 7 shows the results of such a heat resistance test with characteristics of the respective samples under the room temperature. Referring to Table 7, "x mmd`' shows the value of a diameter which caused no abnormality in the coated layer when the copper wire of each sample was wound lZ~37~
on a rod of x mm in diameter in a bending test. Table 7 also shows voltage resistance (V). Table 7 further shows results of insulation-sustainable temperature (C) and vibration-proof temperature ~C). The "insulation-sustainable temperature" indicates.the.maximum temperature capable of sustaining insulating performance and the `'vibration-proof temperature" indicates the maximum temperature capable of sustaining insu~ating performance against the vibration applied in the aforementioned manner.
It is understood from the result of the insulation test that the electric wire in accordance with the present invention is excellent in flexibility and its insulating performance can be maintained under a high temperature.
i;~9~3744 Table 7 Sample ¦ Characteristics under Heat Resis' :ance Test Room TemPera :ure Insulation- Vibration-Bending Test Voltage Sustainable O Prof o Resistance (V) Temperature ( C) Temperature ( C) A 5 mmd200 550 380 B 2 mmd900 700 500 C 2 mmd600 600 550 D 2 mmd>1000 >800 720 E 2 mmd>1000 >800 650 F 2 mmd700 >800 >800 Although the present invention has been:described and illustrated.in detail, it is clearly understood!that the same is by way of illustration.and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
Electric Wire BACKGROUND OF THE IN~7ENTION
Field of the.Invention The prcsent invention relates to an electric wire, and more particularly, it relates to an electric wire which is applied to an electric.wire requiring.fire resistance and heat resistance such as a magnet wire or a wire employed in the vicinity of-a nuclear.reactor, or a special wire or cable requiring corrosion resistance.
Description of the-Prior Art The aforementioned electric wire requiring.heat resistance or corrosion resistance..is-generally prepa.r.ed by a covered conductor, which is coated with organic material. However, an organic coa.ting film is insufficient in long-term stability, heat resistance., chemical durability and the like.
Thus, there has been provided a conductor coated with a compound of metal or metalloid, which.is different from the material for the conductor, in order to attain heat resistance and corrosion resistance. For example, National Patent Publication Gazette No. 501783/1985 in the name.of Raychem Inc., published in Japan on Octo~er 17, 1985, discloses a conductor which is coated with an oxide or a nitride by vacuum deposition, in order to provide q~
lZ~
heat resistance to an elec~ric wire to be utilized under a high temperature. A compound for forming such coating is prepared by an oxide or a nitride of aluminum, silicon e~c. Since such oxide is excellent in heat resistance and corrosion resistance, an electric wire coated with the oxide can be provided with high heat resistance and corrosion resistance.
The aforementioned electric wire which is covered with a ceramic film has been studied for improving these characteristics. Such a ceramic film is formed by:
(a) a method of forming a film from a vapor phase (vapor phase thin film growth method), such-as CVD
(chemical vapor deposition), PVD (physical vapor deposition) or flame coating;
(b) an electrochemical method of forming a film in a solution, such as plating;
(c) a sol-gel method of forming a film from a li~uid phase by chemical reaction of reacting alkoxide; or Id) a method of forming a film by dipping in a melt.
As hereinabove described, it i5 well known that an oxide of ceramics such as A1203 or SiO2 is excellent in heat resistance and corrosion resistance. However, such an oxide formed by vacuum deposition is rather insufficient in adhesion to the material, such as copper, for a conductor. Therefore, when an electric wire coated lZ9879~
with an oxide is used under corrosive environment over a long period of time, for example, the oxide film may partially peel off from the copper surface., to result in corrosion from the exposed portion.
The vapor phase thin film grow~h method such as vacuum deposition is employed as a method of forming.an oxide film on the surface of a conductor. However, a film obtained by vacuum deposition or the like may be inferior in flexibility. Therefore., when a wire coated with an oxide by vacuum deposition is used in a bended state, for example, the oxide film may be broken by stress applied to the surface of the conductor, to result in corrosion from the broken portion.
SUMMAR~ OF THE INVENTION
Accordingly, an object of the present invention is to provide an electric wire which effectuates excellent-heat resistance and corrosion resistance over a long period of time, by forming a film having excellent adhesion.and flexibility. Another object of the present invention is to provide an electric wire which can be industrially obtained by simple means.in a step of coating an elonga.ted wire conductor.
An electric wire in accordance with the present invention comprisRs a conductor and a gel film formed by applying a solution ob.tained by hydrolyzing and lZ~187~
deh~drating/condensillg alkoxide on.o an ou~er ~art of the conductor and leaving the same.
The gel film contributing to heat resistance, which is formed by-a sol-gel method in the present inventionj is excellent in flexibility and adhesion since the same-is left not to be completely changed-into a ceramic state but to remain in a gel state This gel film is changed into a ceramic state by heating, to be improved in heat resistance. However, it has been recogni~ed that its flexibility is reduced as much as it is changed into a ceramic state. On the basis of such a viewpoint of the inventors, the gel film is formed as a main heat resisting layer in the present invention. The conductor is preferably left in an atmosphere-being at a temperature not less than 25C, not more than 400C, in order to form the gel film as a main heat resisting layer.
When the outer surface of a conductor coated with the solution obtained by hydrolyzing and dehydrating/condensing alkoxide and left is oxidized by heat, an oxide thus produced is so fragile that adhesion between the gel film and the conductor surface is lost to cause peeling of the film. In order to prevent this, the conductor surface is preferably plated with Ni or Cr for attaining oxidation resistance, before the same is coated with the solution and left in the aforementioned manner.
~Z9~ 4 Upon heating, the gel film is considerably shrunk to be reduced in thickness. Such shrinkage of the film may result in inferior durability of insulation. While a conductor subjected to low voltage may be simply coated with a gel film alone, a problem is caused in durability of insulation when such a simple coa.ted wire is applied-to a power cable. Therefore, particulates of a metal oxide., a metal nitride or a metal boride are preferably dispersed/mixed-in the.gel film as ceramic filler for suppressing shrinkage.of the gel film.
Although the gel film is considerably flexible in a natural state, such flexibility may be lost when the gel film is heated to be changed into a ceramic state. Even if the electric wire is utilized in a portion-exposed to strong vibration, the film changed into a ceramic state must not peel off from the conductor by cracking.caused.by the strong vibration. Thus, particularly strong adhesion may be required between the gel film and the conductor.
In this case, an adhesion layer may be provided between the gel film and the conductor, or between the gel film and a plating layer formed on the surface of the conductor. The adhesion layer may be prepared by a film completely changed into a ceramic state by applying a solution obtained by hydrolyzing and dehydrating/condensing alkoxide and thereafter heating the lZ~3874~
same. Alternatively, the adhesion layer may be prepared by a ceramic layer formed by CVD, on the basis of such a viewpoint of the inve~tors that a layer formed by CVD is larger in adhesion to a substrate than a gel film.
The inventive wire may be provided with an outermost layer of organic material, in order to improve slipperiness in winding and durability of insulation under the room temperature. In this case-, the particulates of a metal oxide etc. may be~dispersed~mixed in the organic material layer to improve durability of insulation.
Further, the organic material layer may be formed from a solution of organic material, added to which is a solution obtained b~ hydrolyzing and dehydrating/condensing alkoxide with addition of tetraalkylammonium halide to be mixable into the solution of organic material, in order to improve heat resistance.
A gel film in accordance with the present invention may be formed as a multilayer film having two or more layers, in order to improve-heat resistance, corrosion resistance and durability of insulation. In the process of forming the gel film in accordance with the present invention, alkoxide may be hydrolyzed ~y moisture contained in the atmospheric air, without directly adding water to an alkoxide solution.
lZ91~3791~
These and ot'ner objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present-invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION ~F THE DRAWINGS
Figs. lA, lB, lC and lD are sectional views showing electric wires in accordance with the present invention;
and Fig. 2 illustrates an apparatus for performing a heat resistance test on samples of the electric wires in accordance with the present invention.
DESCRIPTION OF THE PREFERRED E~BODIMENTS
Figs, lA to lD are sectional views showing electric wires in accordance with the prese~t invention.
Fig, lA shows an electric wire, which-comprises a conductor 1 of~copper etc, coated with a gel film 2 of one or more layers,- Fig, lB shows an electric wire which comprises a conductor 1, a plating layer 3 of Ni or Cr formed on the suxface thereof, a gel film 2 covering the plating layer 3 and a covering layer 6 of organic material, Fig, lC shows an electric wire which has a gel film 2 and a ceramic film 4 formed under the gel film 2 by CVD to serve as an adhesion layer. Fig. lD shows an electric wire which has a ceramic film 5 formed by a lZ987~
starting raw material of alkoxide, to serve as an adhesion layer. This ceramic film 5 is formed by applying a solution obtained by hydrolyzing and dehydratinglcondensing metal alkoxide and thereafter heating the same.
Samples for a heat resistance test of the aforementioned electric wires embodying the present invention were prepared as follows.: Each of coating solutions-1 to 6, being prepared by the following methods, was applied onto a copper wire of 2.0 mm~ in diameter by a dipping method at a lift-up speed of 1.0 m/min., to form a multilayer film on.the.copper.wire.
Coatinq Solution 1 Tetrabutylorthosilicate ISi(OC4Hg)4], iso~ropyl alcohol ~C3H70H] and water ~H2O] were mixed.in the mole ratio 10:50:40 to obtain.a solution, to which nitric acid was added by 1/100 mol of tetrabutylorthosilicate. Then the solution was stirred at a temperature of 80C for 100 minutes, and thereafter returned to the room temperature.
oatinq Solution 2 Tetraethylorthosilicate [SitOC2H5)4], ethyl alcohol IC2H5OH] and water.lH2O] were mixed.in the mole ratio 3:60:37 to obtain a solution, to which nitric acid was added by 1l100 mol of tetraethylorthosilicate. Then the lZ9~74~
solution was stirred at a temperature o~ 70C for 100 minutes, and thereafter returned to the room temperature~
Coatinq Solution 3 Tetrabutylorthosilicate ISi(OC4Hg)4~, isopropyl alcohol IC3H7OH) and water ~H2O] were mixed in the mole ratio 20:60:20 to obtain a solutionj to which nitric acid was added by 1/100 mol of tetrabutylorthosilicate. Then the solution was stirred at a temperature o~ 80C for 200 minutes, and thereafter returned to the room temperature.
Coating Solution 4 Tetrabutylorthosilicate [Si(OC4H9)4~, isopropyl alcohol IC3H70H] and water IH2O] were mixed in the mole ratio 10:50:40 to obtain a solution of 100 g, to which silicagel by Wako Junyaku (WAXOGEL, C-100) of 30 g was previously added. Then nitric acid was added by 1/100 mol of tetrabutylorthosilicate, and the solution was stirred at a temperature of 80C for 100 minutes, and therea~ter returned to the room temperature.
Coatinq Solution 5 p-xylene 30~ solution of polyimide Coatinq Solution 6 Tetrabutylorthosilicate ISi(OC4Hg)4], isopropyl alcohol [C3H70H] and water ~H2O~ were mixed in the mole ratio 10:50:40 to obtain a solution, to which nitric acid was added by l/100 mol of tetrabutylorthosilicate. Then _ g 12~ 4 the solution was stirred at a temperature of 80C for 100 minutes and.thereafter returned to the room.temperature.
Tetrabutylammonium bromide l(C4H9)4N Br ~ of 20 g was added to the solution of 100 g and stirred with addition of chloroform ICHCl3], to perform extraction.
This extract was decompressed/dried by an evaporator to remove the solvent, thereby to obtain a pale yellow consistent solution lSiO2 polymer]. This SiO2 polymer was mixed into 10 ml of a p-xylene 30% solution of polyimide, which was then stirred under the room temperature.
Each of the coating solutions 1 to 6 was employed for coating, to form a film by the following treatment. Thus, samples A, B, C, D, E and F were obtained by copper.wires having multilayer coating films at least including gel ~ilms, as shown in Tables 1 to 6.
Table 1 (Sample A) 1st Laver 1 2nd Layer 3rd LaYer. 4th Layer SubstanceNi PlatinqGel Gel Gel Coating __ Solution Solution 1 Solution 2 Solution 2 HeaOed at HeaOed at Left at 25C
Treatment__ 280 C for 220 C for for 6 h.
Film 15 min. 15 min.
Thickness 3 2 2.6 20.0 (~m) .
Table 2 (Sample B) _ 1st LaYer 2nd Layer 3rd Layer 4th LaYer-Substance Gel Gel Gel Resin Coating Solution 1 Solution:2 Solution 2 Solution 5 HeaOed atHeaOed at HeaOed at HeaOed at Treatment 280 C for220 C for 170 C for 200 C for 15 min.15 min. 15 min. 30 min.
Film Thickness 2 2.6 11.5 7 (~m) Table 3 (Sample C) .
1st Layer 2nd LaYer 3rd Layer Substance~ Ni Plating Gel Resin Coating Solution __ Solution 1 Solution 5 HeatOed at Hea~ed at Treatment __. 200 C for 200 C for 15 min. 30 min.
Film Thickness 3 5.2 7 (~m) , ,. ~ , .
lZ~l374~
Table 4 (Sample C) ; 1st Layer2nd Layer 3rd Laver SubstanceNi PlatingGel Resin Coating Solution __Solution 4 Solution 5 HeaOed at HeaOed at Treatment__300 C for 200 C for Film 15 min. 30 min.
(~m) 15 Table 5 (Sample E) 1st LaYer 2nd LaYer 3rd Layer SubstanceNi Platin~ Gel Resin Coating Solution _Solution 4 Solution 6 HeaOed at HeaOed at Treatment__ 300 C for 200 C for Film 15 min. 30 min.
(~m) 15 7 - ~2 -lZ9~
Table 6 (Sample F) 1st Layer 2nd Laver 3rd Layer 4th LaYer Substance Ni Platin Ceramics Gel Resin g Coating Solution __ Solution 3 Solution 1 Solution 6 ~eaOed at HeaOed at Heated at Treatment __ 500 C for 200 C for 200C for Film 15 min. 15 min. 30 min.
Thickness ~.3 5.1 Each sample thus obtained was subjected to a heat resistance test as follows:
Heat Resistance Test Insulation Test: As shown in Fig. 2, two samples 7a and 7b were brought into contact with each other to be heated by a heater 12 at à prescribed temperature for 30 minutes with application of voltage of 50 V, thereby to confirm insulating performance.
~ ibration Test: In the insulation test, a motor 15 as shown in Fig. 2 was rotated with a dead weight 16 of 5 g, to apply vibration.
Referring to Fig. 2, numerals 7a and 7b indicate the samples, numeral 8 indicates a quartz plate on which the samples 7a and 7b are placed to be in contact with each lZ~7~4 other, and numeral 9 indicates a quartz pipe for storing the samples 7a and 7b placed on the quartz plate 8, having an end sealed by a closure 10 of silicon rubber and another end blocked by a glass wool member ll. A heater 12 prepared by a tube furnace is provided around the quartz pipe 9, in order to heat the samples 7a and 7b. A
thermocouple 13 is inserted into the quartz pipe 9 through the closure 10, in order to measure the temperatures of the samples 7a and 7b. Numerals 14a and 14b indicate lead wires, which are connected to the-samples 7a and 7b respectively, to be linked to electrodes for the insulation test. The motor 15 is provided on an end of the quartz plate 8 outwardly extending from the quartz pipe 9 through the glass 9 wool member 11, in order to apply vibration to the samples 7a and 7b. The dead weight 16 of 5 g is mounted on the shaft of the motor 15, which is rotated to vibrate the quartz plate 8, thereby to transfer the vibration to the samples 7a and 7b. A
support 17 is provided in order to support the quartz plate 8.
Table 7 shows the results of such a heat resistance test with characteristics of the respective samples under the room temperature. Referring to Table 7, "x mmd`' shows the value of a diameter which caused no abnormality in the coated layer when the copper wire of each sample was wound lZ~37~
on a rod of x mm in diameter in a bending test. Table 7 also shows voltage resistance (V). Table 7 further shows results of insulation-sustainable temperature (C) and vibration-proof temperature ~C). The "insulation-sustainable temperature" indicates.the.maximum temperature capable of sustaining insulating performance and the `'vibration-proof temperature" indicates the maximum temperature capable of sustaining insu~ating performance against the vibration applied in the aforementioned manner.
It is understood from the result of the insulation test that the electric wire in accordance with the present invention is excellent in flexibility and its insulating performance can be maintained under a high temperature.
i;~9~3744 Table 7 Sample ¦ Characteristics under Heat Resis' :ance Test Room TemPera :ure Insulation- Vibration-Bending Test Voltage Sustainable O Prof o Resistance (V) Temperature ( C) Temperature ( C) A 5 mmd200 550 380 B 2 mmd900 700 500 C 2 mmd600 600 550 D 2 mmd>1000 >800 720 E 2 mmd>1000 >800 650 F 2 mmd700 >800 >800 Although the present invention has been:described and illustrated.in detail, it is clearly understood!that the same is by way of illustration.and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
Claims (10)
1. An electric wire comprising a conductor having at least one coating of a film obtained by applying a gel formed by hydrolyzation and condensation of an alkoxide on an outer surface of said conductor, wherein after said gel film has been applied to the conductor it is permitted to remain in a state in which it is not completely changed into condensed oxide.
2. An electric wire in accordance with claim 1, wherein said gel is left in an atmosphere having a temperature of not less than 25°C and not more than 400°C.
3. An electric wire in accordance with claim 1, wherein said conductor is provided on its surface with a plating layer of either Ni or Cr, said coating gel film being formed on the outer surface of said plating layer.
4. An electric wire in accordance with claim 1, wherein said gel film is formed as a multilayer film having two or more layers.
5. An electric wire in accordance with claim 1, wherein particulates of at least a metal oxide, a metal nitride or a metal boride are dispersed/mixed in said gel film.
6. An electric wire in accordance with claim 1, wherein an underlayer of said gel film is an adhesion layer of a ceramic film formed by applying a solution obtained by hydrolyzing and dehydrating/condensing metal alkoxide and thereafter heating the same.
7. An electric wire in accordance with claim 1, wherein an underlayer of said gel film is an adhesion layer of a ceramic film formed by CVD.
8. An electric wire in accordance with claim 1, further including a covering layer of organic material formed on an outer part of said gel film.
9. An electric wire in accordance with claim 8, wherein particulates of at least a metal oxide, a metal nitride or a metal boride are dispersed/mixed in said covering layer.
10. An electric wire in accordance with claim 8, wherein said covering layer is formed from a solution of organic material, added to which is a solution obtained by hydrolyzing and dehydrating/condensing alkoxide with the addition of tetraalkylammonium halide mixable with said solution of organic material.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62115576A JPS63281313A (en) | 1987-05-12 | 1987-05-12 | Heat-resistant electric wire |
| JP115576/1987 | 1987-05-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1298744C true CA1298744C (en) | 1992-04-14 |
Family
ID=14665994
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000566490A Expired - Fee Related CA1298744C (en) | 1987-05-12 | 1988-05-11 | Electric wire |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0292780B1 (en) |
| JP (1) | JPS63281313A (en) |
| AT (1) | ATE58447T1 (en) |
| CA (1) | CA1298744C (en) |
| DE (1) | DE3861058D1 (en) |
| ES (1) | ES2019430B3 (en) |
| GR (1) | GR3001461T3 (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5091609A (en) * | 1989-02-14 | 1992-02-25 | Sumitomo Electric Industries, Ltd. | Insulated wire |
| JP2890631B2 (en) * | 1989-03-28 | 1999-05-17 | 住友電気工業株式会社 | Insulated wire |
| JPH03201311A (en) * | 1989-12-27 | 1991-09-03 | Sumitomo Electric Ind Ltd | Insulated electric wire |
| US5336851A (en) * | 1989-12-27 | 1994-08-09 | Sumitomo Electric Industries, Ltd. | Insulated electrical conductor wire having a high operating temperature |
| JPH03203129A (en) * | 1989-12-28 | 1991-09-04 | Sumitomo Electric Ind Ltd | Manufacture of cable insulated with inorganic insulator |
| DE69033019T2 (en) * | 1989-12-28 | 1999-10-21 | Sumitomo Electric Industries | INORGANIC INSULATION PRODUCTION PROCESS |
| US5436409A (en) * | 1991-01-10 | 1995-07-25 | Sumitomo Electric Industries, Ltd. | Electrical conductor member such as a wire with an inorganic insulating coating |
| JPH04242011A (en) * | 1991-01-10 | 1992-08-28 | Sumitomo Electric Ind Ltd | Inorganic insulative member |
| FR2709592B1 (en) * | 1993-09-02 | 1996-02-02 | Pirelli Cables | Cable resistant to chemical attack. |
| DE69502270T2 (en) * | 1995-02-24 | 1999-01-07 | Sumitomo Electric Industries | Electrical conductor element such as a wire with an inorganic insulating coating |
| US6605674B1 (en) | 2000-06-29 | 2003-08-12 | Ondeo Nalco Company | Structurally-modified polymer flocculants |
| JP2006100168A (en) * | 2004-09-30 | 2006-04-13 | Totoku Electric Co Ltd | Heat-resistant magnet wire and its manufacturing method |
| DE102008039326A1 (en) | 2008-08-22 | 2010-02-25 | IWT Stiftung Institut für Werkstofftechnik | Preparing electrically insulated electric sheet, to prepare laminated magnetic core, comprises coating one side of sheet using liquid mixture comprising hydrolyzed and condensed metal organic monomer, and heat treating coated sheet |
| US8802230B2 (en) | 2009-12-18 | 2014-08-12 | GM Global Technology Operations LLC | Electrically-insulative coating, coating system and method |
| CN102938275B (en) * | 2012-11-19 | 2015-08-12 | 四川明星电缆股份有限公司 | A kind of fire-resistant medium and high voltage cable manufacture method |
| CN102938276B (en) * | 2012-11-19 | 2015-08-12 | 四川明星电缆股份有限公司 | The fire-resistant medium and high voltage cable manufacture method of a kind of safety-type |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1241395A (en) * | 1984-07-08 | 1988-08-30 | James M. O'brien | Electrical wire and cable |
| CA1295890C (en) * | 1985-01-14 | 1992-02-18 | Stephen J. Duckworth | Electrical wire with refractory coating |
| CA1295889C (en) * | 1985-01-14 | 1992-02-18 | Richard J. Penneck | Refractory coated article |
-
1987
- 1987-05-12 JP JP62115576A patent/JPS63281313A/en active Pending
-
1988
- 1988-05-10 AT AT88107511T patent/ATE58447T1/en not_active IP Right Cessation
- 1988-05-10 EP EP88107511A patent/EP0292780B1/en not_active Expired - Lifetime
- 1988-05-10 ES ES88107511T patent/ES2019430B3/en not_active Expired - Lifetime
- 1988-05-10 DE DE8888107511T patent/DE3861058D1/en not_active Expired - Fee Related
- 1988-05-11 CA CA000566490A patent/CA1298744C/en not_active Expired - Fee Related
-
1991
- 1991-02-08 GR GR91400169T patent/GR3001461T3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE3861058D1 (en) | 1990-12-20 |
| JPS63281313A (en) | 1988-11-17 |
| ES2019430B3 (en) | 1991-06-16 |
| EP0292780A1 (en) | 1988-11-30 |
| GR3001461T3 (en) | 1992-10-08 |
| EP0292780B1 (en) | 1990-11-14 |
| ATE58447T1 (en) | 1990-11-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1298744C (en) | Electric wire | |
| US5436409A (en) | Electrical conductor member such as a wire with an inorganic insulating coating | |
| EP0410003B1 (en) | Insulated electric wire | |
| EP0435154B1 (en) | Method of manufacturing mineral insulated wire | |
| US5889459A (en) | Metal oxide film resistor | |
| CA1295890C (en) | Electrical wire with refractory coating | |
| EP0461267B1 (en) | Method of manufacturing inorganic insulator | |
| EP0460238B1 (en) | Insulated wire | |
| JPS63192895A (en) | Coating member | |
| EP0494424B1 (en) | Method for the production of an electrical conductor having an inorganic insulation | |
| JP2565892B2 (en) | Electrical wire | |
| CN107945938B (en) | A kind of polyimides cladding toughness electromagnetic wire | |
| EP0729157B1 (en) | Electrical conductor member such as a wire with an inorganic insulating coating | |
| JPH05314821A (en) | Inorganic insulation coated conductor | |
| CA2142765C (en) | Inorganic insulating member | |
| JPH02270217A (en) | Insulated wire | |
| JP2943196B2 (en) | Heat-resistant insulated wire | |
| JPS6156869B2 (en) | ||
| WO1992002960A1 (en) | Thermocouple | |
| JPH0461711A (en) | Inorganic insulated electric wire | |
| JP2909768B2 (en) | Heat-resistant insulated wire and method of manufacturing heat-resistant insulated wire | |
| JPH0286008A (en) | Inorganic insulated electric wire and manufacture thereof | |
| JPH0462718A (en) | Ceramics-covered insulated wire | |
| RU2097859C1 (en) | Method for producing long conductors based on high-temperature superconducting compounds | |
| JPH02236911A (en) | Ceramics coating member |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |