Abstract: A wire showing satisfactory electrical insulation, mechanical strength, wear resistance, crosslinking properties and appearance may be obtained by coating a conductor with an ethylene/&agr;-olefin copolymer whose density, melt flow rate, decane soluble matter content, melting point and melt tension are controlled to particular ranges. The copolymer may be used singly or in combination with high-pressure low-density polyethylene. Such copolymer provides a coated layer showing tensile strength of not less than 15 MPa, tensile elongation of not less than 400% and taper wear amount of not more than 15 mg. Furthermore, if the resin pressure in the extruder is adjusted to a particular range, high-speed extrusion becomes possible with a smooth apparent coated layer.

Abstract: A process to produce magnesium diboride objects from boron objects with a similar form is presented. Boron objects are reacted with magnesium vapor at a predetermined time and temperature to form magnesium diboride objects having a morphology similar to the boron object's original morphology.

Abstract: This invention concerns a process and a device for producing strip elements for electronically securing articles and a corresponding produced strip element. The aim of the invention is to present a process, a device, and a strip element which can be economically produced according to said process. As for the process, the aim is achieved in that an endless strip of electronically detectable material is fed and is cut into individual segments of a defined length, in that the individual segments are advanced by means of a conveyor, the speed of which is greater than the speed at which the endless strip is fed, the relative velocity being adjusted to provide the desired interval between two consecutive strip segments, and in that the segments separated by intervals are given a coating on one or both sides.

Abstract: In a method of the present invention for producing elastomer/steel-wire composite, a steel wire is drawn through a plurality of drawing dies, and the steel wire is coated with an elastomer within 30 secs. after the steel wire passed through the final drawing die. An apparatus of the present invention for producing an elastomer/steel-wire composite comprises a wire drawer for drawing a steel wire through a plurality of drawing dies, and a rubber coater for coating the steel wire with an elastomer, and the coating is completed within 30 secs. after the steel wire passed through the final drawing die.

Abstract: The present invention relates to a porous electrode wire for use in electrical discharge machining device and the method of manufacturing the same. The wire improves the machining speed at least 15% compared with a conventional zinc coated wire, which results from an increased ability to cool the wire with a cooling liquid, because of the increase in the surface area of the wire due to its having porous surface morphology. Since the surface of the porous wire presents uniform profile of outer periphery rather than surface protrusions, it does not affect machining accuracy. Further, the porous nature of the wire is expected to improve flushability during electrical discharge machining, providing spaces to eliminate particles resulting from the machining. Therefore, in accordance with the method of the present invention, a zinc coated wire having improved performance of machining speed and flushability compared with a conventional coated wire can be provided without additional processes.

Abstract: A tracking resistant electrical insulating material or article suitable for medium to high voltage applications comprising a silane-modified polyolefin, and a heat-shrinkable article prepared therefrom. Said material or article is preferably prepared by a process comprising: (a) reacting polyolefin with a silane in the presence of a free-radical initiator to form a silane-grafted polyolefin, or copolymerising a polyolefin with silane; (b) preparing a mixture of one or more silane-modified polyolefins prepared in (a) with optionally one or more non silane-modified polyolefins, antitrack ingredients, and a silanol condensation catalyst; (c) forming the insulating material or article by melt extruding or moulding said mixture; and (d) crosslinking the insulating material or article by exposing it to moisture, preferably at elevated temperature.

Abstract: The method includes a step in which a conductor wire (4) is coated with a fused plastic material (7) and a step in which said plastic material is cooled, and it is characterized in that it includes a step in which a lubricating material (9) is sprayed onto the surface of the cable (2).

Abstract: A continuous nickel plating process for at least one aluminum conductor includes a pre-treatment step P that improves the adherence of a nickel coat, and an electrolytic nickel plating step N, and is characterized in that the contact properties of the conductor after the pre-treatment step P are sufficient to enable a mechanical electrical contact, and in that the nickel plating current (In=I1) is transmitted to the conductor through a mechanical electrical contact on the part of the conductor output from the pre-treatment step (P). The invention is also directed to a device including a nickel plating tank with a receptacle that can contain a nickel plating bath and at least one electrode called the anode, containing nickel, at least one electrical power supply to apply a voltage (V1) between the electrode, or each electrode, and the conductor or each conductor, and means for moving the conductor in the nickel plating bath.

Abstract: A magnet wire having a boron nitride filled enamel. The enamel can be a resin material having boron nitride particles in an amount effective to impart corona resistance to the magnet wire. A method for manufacturing the magnet wire is also disclosed.

Abstract: A method for providing a tin-plated wire which is free from thermal oxidation yellowing. In a tin-plated wire which comprises a core wire 1 with its surface being formed with a tin-plating layer 2, the composition of the plating is comprised of 30 to 500 wppm gallium, and tin or tin alloy that makes up the remainder thereof. With the content of Ga more than 30 wppm, thermal yellowing is able to be prevented. As too much content of Ga causes surface roughness, the content of Ga must be 500 wppm or below.

Abstract: Nanometer-size wires having a cross-sectional dimension of less than 8 nm with controllable lengths and diameters are produced by infiltrating latent nuclear or ion tracks formed in trackable materials with atomic species. The trackable materials and atomic species are essentially insoluble in each other, thus the wires are formed by thermally driven, self-assembly of the atomic species during annealing, or re-crystallization, of the damage in the latent tracks. Unlike conventional ion track lithography, the inventive method does not require etching of the latent tracks.

Abstract: A method for manufacture of an electric device having at least one conductor and a porous, fibrous and/or laminated electrically insulating dielectric system comprising a solid electrically insulating part impregnated with a dielectric fluid and a porous, fibrous and/or laminated body for use in an electric device produced with the method.

Abstract: Disclosed is a dielectric gelling composition, exhibiting a thermo-reversible liquid-gel transition at a transition temperature, Tt, wherein the gel comprises an oil and a combined gelator system having molecules of a polymer compound together with fine dielectric particles with a particle size in the nanomneter, 6 nm, range, preferably a particle size within the range from 0.001 to 1000 nm, the use of this dielectric gelling composition in an electric device comprising one or more conductors, a casing or enclosure and an insulation system comprising the dielectric gelling composition. An electric DC-cable having a conductor and an electrical insulation comprising a solid part with a porous, fibrous and/or laminated structure impregnated with the dielectric gelling composition and a method for production of such DC-cable wherein the combined gelator is prepared prior to impregnation are also disclosed.

Abstract: Herein is desclosed a curable resin composition comprising at least one polyol selected from the group consisting of Polyol A, including polybutadiene polyol (Polyol Aa), Polyol B, including polybutadiene polyol (Polyol Ba) and polyester polyol (Polyol Bb), and Polyol C, and at least one polyblock isocyanate selected form the group consisting of polyblock isocyanate (Isocyanate X), including polybutadiene polyblock isocyanate (Isocyanate Xa), which is excellent in warp property, i.e., provides a low shrinkage, upon curing, and the cured products of which are particularly excellent in flexibility and excellent in such properties chemical resistance, heat resistance, electric insulation, bending resistance and adherence, and which is, therefore, suitable for overcoat of flexible circuit.

Abstract: An apparatus for coating a substrate with a diamond like coating or other vacuum depositable material comprises a chamber 11 having, or acting as, an anode, means for supporting a substrate 15 in the chamber, means for establishing a low pressure atmosphere containing a hydrocarbon-based gas in the chamber, and a radio frequency source 12 for establishing a gas plasma in the chamber, the substrate 15 acting as a cathode.

Abstract: A method for minimizing formation of cracks at junctions between conductive vias and conductive lines in line-to-via connections on a substrate. The method comprises providing a transition zone connected between a base section of the line and a cap, the transition zone providing a volume of conductive paste during a conductive paste screen printing operation that is greater than the volume provided by the base section being directly connected to the cap. In particular, the transition zone volume is an effective amount to prevent necking of the conductive line into the via when the mask is misaligned to the substrate within an expected alignment tolerance. The transition zone may comprise a jogged end extending from the base section to the cap at an angle to the line, or a flared end extending from the base section. Line-to-via connection structures, patterns on a mask for making such structures, and masks having such patterns are also disclosed.

Abstract: It is particularly an object of the present invention to provide a method for insulating a heater element and carbon filaments which prevent an insulating material from peeling off due to thermal expansion or air expansion, which exhibit the enhanced insulation performance and realize heat resistance and incombustibility, and which are electrically stable even in high temperature areas.

Abstract: A process for high speed melt extrusion onto wire conductors of fluoropolymer pigmented with oxide-coated titanium dioxide.

Abstract: The invention relates to wire enamels comprising as binders polyesterimide and/or polyamideimide, the binders comprising as monomeric building blocks polyoxyalkylenediamine having terminal amino groups. The polyoxyalkylenediamines are preferably selected from the group polyoxyethylenediamine, polyoxypropylenediamine and polyoxyethylenepropylenediamine. The invention also encompasses the use of the novel wire enamels for coating copper wires, especially thick round wires or profiled wires.

Abstract: The present invention relates to a porous electrode wire for use in electrical discharge machining and the method of manufacturing the same. The wire improves the machining speed at least 15% compared with a conventional zinc coated wire, which results from an increased cooling ability of the wire with a cooling liquid because of the increase in the surface area of the wire having porous surface morphology. Since the surface of the porous wire presents uniform profile of outer periphery rather than surface protrusions, it does not affect machining accuracy. Further, the porous nature of the wire is expected to improve flushability during the electrical discharge machining, providing spaces to eliminate particles of the machining. Therefore, in accordance with the method of the present invention, a zinc coated wire having improved performance of machining speed and flushability compared with a conventional coated wire can be provided without additional processes.

Abstract: A process for producing a pattern in the surface coating of an electrode used in an electrochemical machining process comprises the steps of providing a cylinder having a body composed of an electrically conductive material and a surface coating of an electrically insulating material and exposing the surface coating of the cylinder to a source of light in accordance with the pattern. Locators(s) may optionally be formed on the surface of the cylinder to assist in positioning the electrode in a predrilled hole.

Abstract: The present invention relates to a porous electrode wire for use in electrical discharge machining and the method of manufacturing the same. The wire improves the machining speed at least 15% compared with a conventional zinc coated wire, which results from an increased cooling ability of the wire with a cooling liquid because of the increase in the surface area of the wire having porous surface morphology. Since the surface of the porous wire presents uniform profile of outer periphery rather than surface protrusions, it does not affect machining accuracy. Further, the porous nature of the wire is expected to improve flushability during the electrical discharge machining, providing spaces to eliminate particles of the machining. Therefore, in accordance with the method of the present invention, a zinc coated wire having improved performance of machining speed and flushability compared with a conventional coated wire can be provided without additional processes.

Abstract: The invention relates to electric power cables, transmission lines or coaxial cables having at least one polymeric component. This polymeric component generally is a conducting, semiconducting, protective or insulating component. The electrical cables of this invention have improved resistance to water treeing and other improved properties. The polymer generally comprises ethylene polymerized with at least one C3 to C20 alpha-olefin and optionally at least one C3 to C20 polyene. The polymer utilized has a density in the range of about 0.86 g/cm3 to about 0.96 g/cm3, a melt index in the range of about 0.2 dg/min. to about 100 dg/min., a molecular weight distribution in the range of about 1.5 to about 30, and a composition distribution breadth index greater than about 45 percent.

Abstract: A pre-twisted cable pair and a method for processing such pairs into an electrical cable having improved electrical and mechanical properties is disclosed. At least one insulated wire for transmitting electrical signals is pre-twisted prior to pairing with another insulated wire. As the pre-twisted wires are paired by a conventional double-twist machine which imparts back-twist, the detrimental electrical effects caused by irregularities in the individual wires are cycled over a very short distance, resulting in a cable pair having lower structural return loss, near-end crosstalk, and insertion loss than wires paired without any pre-twist. These pre-twisted wires may be united into a jacketed electrical cable by a continuous-extrusion jacketing process in which an optimal dielectric constant is maintained around each individual cable pair.

Abstract: A liquid output portion is arranged above a substrate. In the substrate, a film formation region and a non-film-formation region are determined. The liquid output portion is responsible for continuously outputting a liquid in a constant amount to the substrate. The substrate and the liquid output portion are relatively moved by a moving portion. Below the liquid output portion, a liquid shut-out portion is arranged. At least one of the substrate and the liquid output portion is moved and ready to supply of the liquid from the liquid output portion to the non-film-formation region, the supply is shut out by the liquid shut-out portion. A liquid, which has been controlled so as to spread in a constant amount, is continuously output from the liquid output nozzle to the substrate. While the nozzle and the substrate are relatively moved, the liquid is supplied to a first region on the substrate.

Abstract: A communications cable is provided having at least one elongate electrical conductor surrounded by a layer of insulating material, said layer comprising a foamed fluorinated polymer formed using a liquid or solid blowing agent having a vaporization temperature at ambient temperature of between about 140° F. and about 700° F. The elongate electrical conductors can be provided as at least one pair of twisted wires, each wire thereof surrounded by a layer of insulating material comprising the foamed fluorinated polymer. The communications cable includes insulated wires which possess a layer of foamed fluorinated polymer insulating material having uniform thickness and electrical properties along the length of the wire. In addition, the fluorinated polymer can be applied on the conductor in a relatively thin layer which minimizes the amount of fluorinated polymer material used to insulate the individual conductors.

Abstract: A conductive composite is described containing silver particles and a polymer which covers each silver particle and wherein a heterocyclic organic compound containing nitrogen such as benzotriazole (BTA) is present to reduce Ag dissolution and ion mobility by forming a water insoluble complex with the Ag ion. The invention overcomes the problem of silver dissolution or corrosion a conductive composite as a result of normal high Ag ion mobility in the presence of moisture and an electric field.

Abstract: A method for enhancing the dielectric properties of an electrical cable having a central stranded conductor encased in a polymeric insulation. The cable defines an interstitial void space (v.sub.1) between the strands of the conductor. The volume (v.sub.2) of a dielectric enhancement fluid required to be absorbed by the cable to reach a predetermined level of dielectric enhancement is determined. The ratio of (v.sub.1 /v.sub.2) is computed. If the ratio of (v.sub.1 /v.sub.2) is greater than a maximum ratio of 1.4, then a quantity of the dielectric enhancement fluid is diluted with a sufficient quantity of a diluent to produce a mixture of diluent and dielectric enhancement fluid, such that when the volume (v.sub.1) of the mixture is supplied to the cable interior, the cable will have been supplied with a volume (v.sub.3) of the dielectric enhancement fluid within the mixture such that (v.sub.3 /v.sub.2) is less than 1.4.

Abstract: A process for the manufacture of wires with a brass surface and a predefined zinc content for application in wire electroerosion. Wire (32) made of copper or brass is passed through heated treatment chamber (14) filled with a zinc vapor, wherein the zinc in gas phase diffuses in wire (32). The concentration of zinc in gas phase and the temperature (T.sub.D) of wire (32) in treatment chamber (14) are regulated in such a way that the zinc content of the brass phase forming on the surface of the wire suitably corresponds to the predefined zinc content.

Abstract: This invention concerns a scanning electrochemical microscope prove capable of measuring a specimen which does not have a smooth surface. The probe is insulated by a monomolecular adsorption film, a monomolecular laminated film, or polymer film (i.e., organic thin film). Its front end has the organic thin film removed by an electric field evaporation process to expose the metal wire, and the current is detected by this portion. Active hydrogen is present on the surface of the metal wire which preferably has a pointed end. A silane surfactant such as octadecyl trichlorosilane or the like is brought into contact with the metal wire surface to cause a dehydrochlorination reaction, thereby forming a monomolecular film, a monomolecular laminated film, or polymer film which is chemically adsorbed by colvant siloxane bonds to the surface of the metal. Only the front end portion of the metal wire is evaporated by the electric field, so that a probe with a very fine tip is obtained.

Abstract: A new form of construction for synthetic cables used for the anchoring of floating platforms in offshore oil production is described. A desirable requisite for this application is that the durability of the cable is not affected by deterioration of its strong core by virtue of the aggressive mechanical action of particles of the sea bed which might penetrate the cable and reach its core. For this purpose a layer (2) to protect the core (1) comprising a strip of polymer material placed in helical fashion which permits the passage of water and prevents the passage of particles of the sea bed towards the core (1) is placed between the cable core (1) and its outer braided protective layer (2).

Abstract: When enveloping an electrical or an optical conductor, the method applies a radiation-reactive resin having photoinitiators with an absorption maximum onto the conductor and then the resin is cured by subjecting it to a radiation of a wavelength preferably in the wavelength range for the absorption maximum of the photoinitiators. The apparatus for enveloping includes an arrangement for applying the resin followed by a radiation source for applying the radiation of the desired wavelength that falls into the range of the absorption maximum of the photoinitiators of the resin.

Abstract: Apparatus and systems for applying filling compound, such as water blocking compound, and water absorbing powder to a core wire or wires of a stranded conductor or to subsequent layers of a stranded conductor, which are particularly suitable for use with a tubular strander, include a rotatable head, which may be positioned downstream of a wire strander. The core is drawn through a core passage where the filling compound is applied to the core and powder is applied to the filling compound. Strand through passages are provided through the rotatable head, for drawing the strand wires therethrough, without being coated. The strand wires are stranded about the core in a closing die. Preferably, the powder circulation circuit is a closed circuit, enabling recycling of the powder. The powder is preferably fluidized prior to its delivery to the applicator, and is withdrawn from the applicator under a slight vacuum.

Abstract: An interconnection contact structure assembly including an electronic component having a surface and a conductive contact carried by the electronic component and accessible at the surface. The contact structure includes an internal flexible elongate member having first and second ends and with the first end forming a first intimate bond to the surface of said conductive contact terminal without the use of a separate bonding material. An electrically conductive shell is provided and is formed of at least one layer of a conductive material enveloping the elongate member and forming a second intimate bond with at least a portion of the conductive contact terminal immediately adjacent the first intimate bond.

Abstract: Process for the reduction of breakdown risks with respect to the solid dielectric insulant of transmission cables and lines operating under high voltages. The insulant normally separates the conductors of a multi-conductor line or the central conductor and the outer metal envelope of a coaxial line. Small amounts of metal particles with dimensions below 1 micron are added to the dielectric insulant mass.

Abstract: A method of altering a portion of the semiconductive layer of an electric power cable, to increase its resistance so as to render it electrically insulative. The semiconductive layer is loaded with carbon powder which forms chains to provide conductive pathways through the layer. By introducing an intercalant into the semiconductive layer, which causes the layer to swell, the conductive pathways are interrupted and the material is rendered insulative (>10.sup.4 .OMEGA.-cm). The intercalant may be a polymerizable material with a curing agent which is cured in situ, i.e., without removing the semiconductive layer from the cable. By this method, flashover to the semiconductive layer at a cable splice or termination may be prevented without requiring tedious removal of the exposed portion of the semiconductive layer. The method is usable with both strippable and coextruded semiconductive layers.

Abstract: A heat-resistant combination including a substrate, a first layer, and a second layer. The first layer includes a benzisidazole-based polymer with a first face in contact with the substrate; and the second layer contains a ceramic material and is securely fixed to a second face of said first layer.

Abstract: A passenger seat comprising: a frame element, vehicle anchorage means connected to the frame element, a seat body comprising a resilient material fixed with respect to the frame element and trim cover attachment means, the trim cover attachment means comprising a relatively high density, rigid foam member having a groove disposed in a surface thereof, the groove capable of receiving connection means comprised in a trim cover. A process, system and mold for producing a passenger seat are also described.

Abstract: A system including the method and apparatus for encapsulating electric wire splices wherein a plurality of electrical conductors in substantially aligned opposed relationship are electrically spliced and an encapsulation mass of thermoplastic dielectric material forms an insulative jacket over the splice. Encapsulation is produced by coating the spliced conductors with a liquified hot melt sealant, agitating and projecting the sealant toward the splice to fill small interstices between the conductors, removing the coated splice and conductors from the liquid sealant and drying the sealant into a dielectric jacket surrounding the splice.

Abstract: Insulated electrical cables which are suitable for use in gasoline fuel tanks comprise a stranded conductor which is blocked by a polysulfide and is covered by polyamide insulation.

Abstract: A conductive wire coated with an improved electrical insulation and methods for the preparation of same. The methods involve coating a conductive wire with an insulating material that comprises a curable acrylate-modified aminoamide resin. The insulated conductive wires possess highly desirable properties, including, for example, desirable dielectric strength, heat-resistance, flexibility, mechanical properties and/or uniformity.

Abstract: The present invention relates to solderable wire-coating compositions based on hydroxyl group-containing polyesters, blocked polyisocyanates, organic solvents and catalysts, which are characterized in that they containA) from 7 to 25% by weight of hydroxyl group-containing polyesters,B) from 55 to 70% by weight of a fully blocked aromatic diisocyanate adduct or of a plurality of fully blocked aromatic diisocyanate adducts,C) from 0.1 to 3% by weight of catalysts,D) from 1 to 8% by weight of a polyol or of a plurality of polyols, andE) from 1 to 36.9% by weight of an alkylene carbonate or of a plurality of alkylene carbonates,the total weight of the wire-coating compositions in each case being 100% by weight.The present invention also relates to a process for the continuous coating of wires using the solderable wire-coating compositions described.

Abstract: A wiring forming method includes a step of forming an oxide film on a silicon substrate, a step of forming a connection hole whose aspect ratio is larger than 1 in the insulation film, a step of forming an Al wiring film on the entire surface by the bias sputtering method and heating the silicon substrate to cause Al wiring film to flow into and fill the connection hole, and a step of processing Al wiring film to form an Al wiring.

Abstract: A manufacturing apparatus of composite filter used as a bead core filter for preventing an electomagneric interference. Particularly, it comprises an element pre-heating section for pre-heating the element through the heaters by conveying vertically the filter element by top and bottom rollers, a coating element coating section for guiding the pre-heated filter element through a guide shaft and passing through a top of the powder disher whereby coating by soaking to the coating agent, and a hardening section for passing in a wave form so as to harden the filter element finished the coating.

Abstract: The present invention relates to an insulating composition for electrical cable comprising a mixture of an ethylene-alkyl acrylate or ethylene-vinyl acetate copolymer and of a polymeric compound, said polymeric compound being an ethylene-alkyl acrylate-maleic anhydride terpolymer or an ethylene-vinyl acetate-maleic anhydride terpolymer, and usual additives such as, for example, a crosslinking agent, its use for the preparation of an insulation sheath of electrical cables and the insulation sheath obtained.

Abstract: A process and device for the preparation of coatings on wires or fiber-like materials by mixing one or more polymers which contain carboxyl and/or amide groups (A) and with at least two carboxyl and/or amide groups, a hydroxyl number of less than 130 and a number average molecular weight of 200 to 5000, in the liquid state, with one or more polyisocyanates (B) with at least two free isocyanate groups in the molecule and a number average molecular weight of 200 to 3000, in the liquid state, and optionally one or more other components (C) which are normally present in lacquers, in the liquid state, continuously immediately before application in a ratio such that 0.5 to 5.0 isocyanate groups are allotted to each carboxyl group or that 0.02 to 2.

Abstract: A sealing material preferably having a cone penetration of at least 150 (10.sup.-1 mm) and an ultimate elongation of at least 100% is subjected to mechanical deformation by milling or chopping in the presence of a solvent or suspending medium.

Abstract: Disclosed is a heat-resistant, high-voltage insulated lead wire for direct current, which meets the demand for higher heat resistance, and its insulating coating over the conductor is formed by a polyolefin resin composition. The polyolefin resin composition is a flame-retarded resin composition comprising of a mixture of a polyethylene whose crystalline component has melting point higher than 125.degree. C. and a copolymer of ethylene and .alpha.-olefin, which contains a multifunctionalized monomer having unsaturated carbon-carbon bond moiety in the molecule as an indispensable component. The insulating coating made of this resin composition is irradiated by an ionizing radiation to give a heat-resistant, high-voltage lead wire for direct current, which has a perpendicular flame resistance (VW-1) acceptable in the UL Standards and has a temperature rating of higher than 125.degree. C.

Abstract: The micropin array is comprised of a plurality of micropins having a given diameter and being aligned in parallel to one another at a given pitch, insulating tubular coatings disposed to cover individual micropins, and an adhesive provided to fill spacings among the insulating tubular coatings. This micropin array is produced by the steps of preparing a plurality of coated wire materials composed of a metal core having a given diameter and an insulating tubular coating of a given thickness formed around the metal core, aligning closely and successively the coated wire materials to form a bundle thereof, fixing the bundle of the coated wire materials by means of an adhesive, and cutting the fixed bundle of the coated wire materials by a given length to form a micropin array.

Abstract: A method of making a heat-resistant coated electrically conductive wire is provided. The method involves forming an insulating coating of one or more thermoplastic resins containing aromatic rings or complex rings which are not cross-linkable alone by electron beams. Exemplary resins are polyetheretherketone, polyamide, polyetherimide, polyallylate, polycarbonate and polysulfone. The method then involves subjecting the insulating coating to irradiation with an accelerated ion beam, which cross-links the resin or resins. The energy of the accelerated ion beam is in a range of 0.1 MeV to 50 MeV, and the dose of the accelerated ion beam is in a range of 1.times.10.sup.11 ions/cm.sup.2 to 1.times.10.sup.15 ions/cm.sup.2.