JP5102541B2 - Insulated wire - Google Patents

Description

  The present invention relates to an insulated wire used in an electric device such as a motor or a transformer, and relates to an insulated wire excellent in resistance to bending or the like.

  In general, an insulated wire called an enameled wire is provided with an insulating film made of an insulating paint around a conductor. When an electrical device such as a motor or a transformer is manufactured using this enameled wire, the enameled wire is generally wound around a slot of a motor core (magnetic core) continuously in a coil shape. Alternatively, a method in which an enameled wire wound in a coil shape is fitted and inserted into a slot of the core has been the mainstream.

  In recent years, for example, coils of electrical equipment used in automobile generators are small and require high-density magnetic flux, so enamel wires with a large cross-sectional area (thick size), An enameled wire with a flat rectangular conductor is used. When manufacturing motors, transformers, etc. using such enameled wires, form a plurality of short small-diameter coils with a small number of turns, weld the end portions of the enameled wires of these small-diameter coils, and connect them together. A method of forming a coil has been proposed.

  For coils of electrical equipment used in automobile generators, etc., a double-coated wire with a polyesterimide insulation film formed around the conductor and a polyamideimide insulation film around the polyesterimide insulation film, Single-coated wires with an insulating coating of polyamideimide around are mainly used. In some cases, double-coated wires with a polyimide insulating film formed around the conductor and a polyamide-imide insulating film around the polyimide insulating film to improve heat resistance and mechanical strength are also used. (For example, refer to Patent Document 1).

  In addition, while maintaining the mechanical properties, heat resistance, flexibility, and electrical insulation properties required for enameled wires, a film with excellent adhesion to conductors, wear resistance, and adhesion after thermal degradation A polyesterimide resin having an isocyanurate ring that can be formed is also used (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 5-130759 JP 2006-001996 A

  However, when using a conventional enameled wire made of polyesterimide and polyamideimide and winding it continuously around a core (magnetic core) slot to produce a coil for electrical equipment, The insulation film is pushed up from the surface of the conductor due to the stress caused by the bending process that occurs when the core is fitted and inserted into the slot of the core. There was a problem that decreased.

  Further, in the wire drawing process of enameled wire production, there is a problem that electrical characteristics deteriorate, such as large irregularities on the surface of the insulating film and partial dielectric breakdown.

  On the other hand, an enameled wire paint to which a silane coupling agent is added is applied to a conductor and baked. However, in this method, particularly when the enamel wire paint is a polyesterimide resin paint containing a titanium catalyst, the silane coupling agent inhibits the curing action of the titanium catalyst present in the enamel wire paint. There is a problem that the hardening of the enameled wire coating is not accelerated and the hardness of the outermost insulating film is lowered. In particular, when the pencil hardness of the outermost insulating film is 4H or less, there is a problem that a surface is damaged in a processing step such as bending and an excellent insulating film cannot be formed.

  Then, the objective of this invention is providing the insulated wire excellent in tolerance, such as a bending process, solving the said subject.

In order to achieve the above object, the present invention is formed by applying a conductor and a silane coupling agent of 3-glycidoxypropyltrimethoxysilane or 3-aminopropyltrimethoxysilane to the outer periphery of the conductor. and innermost insulating coating and applying an enamel wire coating on the innermost insulating coating comprises an insulating film comprising a polyester-imide film is formed by baking, or the outermost insulation film comprising polyamide-imide film, and the The film thickness of the innermost insulating film is 5% or less of the film thickness of the entire insulating film .

  The average surface roughness Ra of the conductor may be 0.2 to 1.0 μm.

  The peel strength for peeling the insulating film from the conductor may be 300 N / m or more.

  The outermost insulating film may have a pencil hardness according to JIS S 6006 of 6H or more.

  The insulating film is formed by applying a paint as a material for the innermost insulating film on the outer periphery of the conductor and baking the outermost insulating film, and then forming the outermost insulating film on the outer periphery of the innermost insulating film. The outermost insulating film may be formed by applying a paint as a film material and baking it.

  The conductor may be a flat conductor.

  ADVANTAGE OF THE INVENTION According to this invention, the insulated wire excellent in insulation performance and workability can be provided.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, an insulated wire 1 according to the present invention includes a conductor 2, an innermost insulating film 4 formed by applying a silane coupling agent to the outer periphery of the conductor 2, and an innermost insulating film 4. And an insulating film 3 comprising an outermost insulating film 5 formed by applying and baking an enamel wire paint. The film thickness of the innermost insulating film 4 is preferably 5% or less of the film thickness of the entire insulating film 3.

  Since the insulated wire 1 shown in FIG. 1 uses a round conductor having a circular cross section as the conductor 2, the conductor 2 is formed so that the innermost insulating film 4 and the outermost insulating film 5 are sequentially concentrically covered. Has been.

  As shown in FIG. 2, the insulated wire 1a according to the present invention includes a conductor 2a, an innermost insulating film 4a formed by applying a silane coupling agent to the outer periphery of the conductor 2a, and an innermost insulating film 4a. An insulating film 3a comprising an outermost insulating film 5a formed by applying and baking an enameled wire paint thereon is provided.

  The insulated wire 1a shown in FIG. 2 uses a rectangular conductor with a flat cross section as the conductor 2a, and the conductor 2a is formed so as to cover the innermost insulating film 4a and the outermost insulating film 5a sequentially. In the following description, the symbol a is not used, but the contents common to the insulated wires 1 and 1a are shown.

  The material of the constituent material of the conductor 2 is not particularly limited as long as it is conventionally used as an enameled wire conductor, and copper or a copper alloy is preferable. Also, the cross-sectional shape of the conductor 2 is not particularly limited, and may be any one such as a circular conductor or a flat conductor. Further, the cross-sectional area (size) of the conductor 2 is not particularly limited, and any conductor that is conventionally used as an enameled wire conductor can be applied.

  It is preferable to form a roughened surface having an average surface roughness Ra of 0.2 to 1.0 on the conductor 2 by etching using hydrogen peroxide and sulfuric acid. When the average surface roughness Ra is less than 0.2, the effect of suppressing film floating and blister generation is reduced. When the average surface roughness Ra exceeds 1.0, a decrease in electrical characteristics such as dielectric breakdown occurs.

  The silane coupling agent used as the material of the innermost insulating film 4 has an effect of improving the adhesion strength between the conductor 2 and the innermost insulating film 4 and improving the adhesion strength with the outermost insulating film 5. If there is no particular limitation. For example, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (Aminoethyl) -3-aminopropylpropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like are preferable, but are not limited thereto.

  As the material of the outermost insulating film 5, it is preferable to use one or more kinds of polyesterimide resin, polyamideimide resin, polyimide resin, polyester resin, and polyurethane resin. That is, the outermost insulating film 5 is any one of a polyesterimide film, a polyamideimide film, a polyimide film, a polyester film, and a polyurethane film.

  The material of the innermost insulating film 4 and the material of the outermost insulating film 5 are provided in the state of paint (enamel wire paint). Accordingly, the innermost insulating film 4 is formed by applying a paint as the material of the innermost insulating film 4 to the outer periphery of the conductor 2 and baking it, and then the outermost insulating film 5 is formed on the outer periphery of the innermost insulating film 4. The outermost insulating film 5 is formed by applying and baking a paint as a material, and the insulating film 3 is produced. There are no particular restrictions on the brand of paint.

  In the present invention, the film thickness of the innermost insulating film 4 must be 5% or less of the film thickness of the entire insulating film 3 (the innermost insulating film 4 and the outermost insulating film 5), and 1% or less. Is preferred. This is because when the film thickness of the innermost insulating film 4 exceeds 5% of the film thickness of the entire insulating film 3, the effect of suppressing film floating and blistering is reduced.

  The principle of the present invention and its operation will be described below.

Conventionally, when an insulated wire wound in a coil shape is inserted into a slot of a core, the insulating film is pushed up from the conductor surface due to the stress caused by the bending process, etc., and the insulating film is peeled off from the conductor. As a result, the insulating film rises. As a result of intensive studies to suppress the floating of the insulating film, the present inventors have found the following.
(1) The average surface roughness Ra of the conductor 2 having a roughened surface needs to be 0.2 to 1.0 μm. Examples of the method for roughening the conductor 2 include, but are not limited to, etching using hydrogen peroxide and sulfuric acid, roughening by forming copper plating, and surface polishing by sandblasting.
(2) As a material constituting the innermost insulating film 4 that is in direct contact with the conductor 2, a silane coupling agent that exhibits high adhesion to the conductor 2 and the outermost insulating film 5, and further exhibits a rust prevention effect of the conductor 2. Is preferred. In addition, after forming the innermost insulating film 4 made of a silane coupling agent, when forming the outermost insulating film 5 composed of a polyesterimide film, the action of the titanium-based catalyst present in the outermost insulating film 5 is increased. The outermost insulating film 5 having sufficient hardness can be formed without hindering. Examples of the titanium-based catalyst used for curing the polyesterimide film include commonly used compounds such as tetraisopropyl titanate and tetra-n-butyl titanate.
(3) In addition to the polyester film, the outermost insulating film 5 can be one that has high heat resistance and is difficult to be thermally decomposed. Examples thereof include an excellent polyamideimide film, polyimide film, polyester film, and polyurethane film.
(4) As a material constituting the outermost insulating film 5, it is necessary to use a material having high adhesion strength to the innermost insulating film 4 that is in direct contact with the conductor 2. This is because when the adhesion strength between the conductor 2 and the insulating film 3 is higher than the force (or the lifting force) at which the insulating film 3 peels from the conductor 2, film floating and blister generation can be suppressed.

  As mentioned above, based on (1)-(4), as a result of further investigations by the present inventors, the present invention was reached. That is, the innermost insulating film 4 around the conductor 2 having the roughened surface is a silane coupling agent film, and the outermost insulating film 5 is a polyesterimide film, a polyamideimide film, a polyimide film, a polyester film, or The film thickness of the innermost insulating film 4 is set to 5% or less of the entire film thickness of the insulating film 3. As a result, an enameled wire having an adhesion strength between the conductor 2 and the innermost insulating film 4 of 300 N / m or more can be produced, and it is possible to suppress film floating and blistering. Further, the outermost insulating film 5 has a pencil hardness as high as 6H or more, and it is possible to form the insulating film 3 having excellent resistance to bending.

  The silicon atoms derived from the silane coupling agent are X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX), Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), and highly sensitive reflection red. It can be measured by external spectroscopy (IRRAS).

  It goes without saying that the present invention is not limited to the above-described embodiment, and various other types are envisaged. Next, although an example is described, the present invention is not limited to this example.

Example 1
1% of 3-glycidoxypropyltrimethoxysilane (KBM-403; manufactured by Shin-Etsu Chemical Co., Ltd.) is obtained by roughening a rectangular copper conductor using a roughening solution (HIST-7300; manufactured by Hitachi Chemical). The aqueous solution was applied onto a rectangular copper conductor and heated at 100 ° C. for 5 minutes in a far infrared heating furnace to provide a 1 μm innermost insulating film. A polyesterimide paint (EH-402; manufactured by Dainichi Seika Co., Ltd.) was applied around the innermost insulating film, and then baked to provide an outermost insulating film having a film thickness of 30 μm. As a result, an enameled wire having a total thickness of 31 μm was produced.
(Implementation 2)
An enameled wire was prepared in the same manner as in Example 1 except that 3-aminopropyltrimethoxysilane (KBE-903; manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of KBM-903.
(Implementation 3)
An enameled wire was prepared in the same manner as in Example 1 except that a polyamideimide (HI-404; manufactured by Hitachi Chemical Co., Ltd.) paint was used instead of the polyesterimide paint.
Example 4
An enameled wire was produced in the same manner as in Example 2 except that a polyamideimide (HI-404; manufactured by Hitachi Chemical Co., Ltd.) paint was used instead of the polyesterimide paint.
(Comparative Example 1)
After applying a polyesterimide paint alone to a flat copper conductor, baking was performed to provide a single-layer insulating film. This produced an enameled wire.
(Comparative Example 2)
A rectangular copper conductor was coated with a 10% aqueous solution of 3-methacryloxypropyltrimethoxysilane (KBM-503; manufactured by Shin-Etsu Chemical Co., Ltd.) on a rectangular copper conductor, and 100 ° C. in a far infrared heating furnace. An innermost insulating film of 2 μm was provided by heating in 5 minutes. A polyamideimide (HI-404; manufactured by Hitachi Chemical Co., Ltd.) coating material was applied around the innermost insulating film and then baked to provide an outermost insulating film having a film thickness of 30 μm. As a result, an enameled wire having a total thickness of 32 μm was produced.
(Comparative Example 3)
10% of 3-aminopropyltrimethoxysilane (KBM-903; manufactured by Shin-Etsu Chemical Co., Ltd.) is obtained by roughening a rectangular copper conductor using a roughening solution (HIST-7300; manufactured by Hitachi Chemical Co., Ltd.). The aqueous solution was applied onto a rectangular copper conductor and heated at 100 ° C. for 5 minutes in a far infrared heating furnace to provide a 2 μm innermost insulating film. A polyamideimide (HI-404; manufactured by Hitachi Chemical Co., Ltd.) coating material was applied around the innermost insulating film and then baked to provide an outermost insulating film having a film thickness of 30 μm. As a result, an enameled wire having a total thickness of 32 μm was produced.
(Comparative Example 4)
An enameled wire was prepared in the same manner as in Comparative Example 3 except that a polyamideimide coating was used instead of the polyesterimide coating.
(Comparative Example 5)
A flat copper conductor was polished with a brass brush at a rotation speed of 200 rpm for 3 minutes, and then a polyesterimide paint was applied alone, followed by baking to provide an insulating film. This produced an enameled wire.
(Comparative Example 6)
After polishing a rectangular copper conductor with a true bell brush at a rotation speed of 200 rpm for 3 minutes, a 50% aqueous solution of 3-methacryloxypropyltrimethoxysilane (KBM-503; manufactured by Shin-Etsu Chemical Co., Ltd.) The innermost insulating film having a thickness of 2 μm was formed by coating on a copper conductor and heating in a far infrared heating furnace at 100 ° C. for 5 minutes. A polyamideimide (HI-404; manufactured by Hitachi Chemical Co., Ltd.) paint alone was applied around the innermost insulating film and then baked to provide an outermost insulating film having a film thickness of 32 μm. Thus, an enameled wire having a total thickness of 40 μm was produced.

  About implementation fall 1-4 and Comparative Examples 1-6, the conductor surface was observed with the laser microscope and the surface roughness of the conductor was measured. Further, the thickness of the innermost insulating film was measured from Auger spectroscopic analysis, and the ratio of the innermost insulating film / the entire insulating film was calculated by measuring the thickness of the entire insulating film with a micrometer. In addition, the oxide film thickness on the conductor surface was measured by electrochemical reduction potential measurement.

  Furthermore, the peel strength between the conductor and the insulating film was measured by the following method. The adhesion strength between the conductor and the insulating film was measured by the following method. First, after each enamel wire was manufactured, a sample piece having a length of about 5 cm was cut from each enamel wire. Thereafter, two cuts extending in the longitudinal direction of the sample piece were formed at intervals of 1 mm on the insulating film on the upper surface or the lower surface (one of the wider surfaces) of each sample piece using a cutter or the like. The longitudinal ends of the insulating film between the cuts were peeled from the conductor using tweezers or the like to form a grip allowance. Thereafter, each sample piece was fixed to a jig, the gripping margin was sandwiched between chucks, and the insulating film was further peeled from the conductor using a Tensilon universal testing machine. At this time, the peel strength (adhesion strength) when the insulating film was peeled off with a length of 1 mm was measured.

  In addition, the stipulated in JIS S 6006 is cut into a blade shape with an angle of about 60 °, and this is pressed against the test piece with a force of about 5 N at an angle of about 60 °, and the stipulated in the length direction of the test piece It was visually inspected whether the film peeled as much as the conductor appeared when it was scratched once.

  Table 1 shows the results of various characteristic evaluations.

  As shown in Table 1, each enameled wire of Examples 1 to 4 has an insulating film composed of two layers around a conductor having a roughened surface, and the innermost insulating film in contact with the conductor is a silane cup. It is a ring agent film, the outermost insulating film is a polyesterimide film, and the film thickness of the innermost insulating film is 5% or less of the film thickness of the entire insulating film. In addition, by providing a silane coupling agent film as the innermost insulating film on the outer periphery of a conductor having a roughened surface with an average surface roughness Ra of 0.2 to 1.0 μm, adhesion by roughening and chemical treatment is achieved. The peel strength between the conductor and the insulating film became 300 N / m or more due to the improvement of the property.

  In addition, the silane coupling agent that becomes the innermost insulating film accelerates the hardening of the enamel wire paint without inhibiting the hardening action of the titanium-based catalyst present in the polyesterimide that becomes the outermost insulating film. Has a high pencil hardness of 6H or more, and can form an insulating film excellent in resistance to bending or the like.

It is sectional drawing of the insulated wire which shows one Embodiment of this invention. It is sectional drawing of the insulated wire which shows one Embodiment of this invention.

Explanation of symbols

1 Insulated wire 2 Conductor 3 Insulating film 4 Innermost insulating film 5 Outermost insulating film

Claims (5)

A conductor, an innermost insulating film formed by applying a silane coupling agent of 3-glycidoxypropyltrimethoxysilane or 3-aminopropyltrimethoxysilane to the outer periphery of the conductor, and the innermost insulating film applying an enamel wire coating above, polyesterimide film is formed by baking or an insulating film comprising the outermost insulating film comprising polyamide-imide film, provided with a film thickness of the insulating coating of the innermost insulating coating, An insulated wire characterized by being 5% or less of the total film thickness . The insulated wire according to claim 1, wherein an average surface roughness Ra of the conductor characterized in that it is a 0.2 to 1.0 [mu] m. The insulated wire according to claim 1 or 2, wherein a peel strength for peeling the insulating film from the conductor is 300 N / m or more. The insulated wire according to any one of claims 1 to 3, wherein the outermost insulating film has a pencil hardness of 6H or more according to JIS S 6006. The insulated wire according to any one of claims 1 to 4 , wherein the conductor is a flat conductor.

Images