JPH07320573A - Manufacture of rectangular superthin film insulated wire - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a rectangular superthin film insulated wire capable of maintaining the initial condition of manufacture for a long period by preventing a number of pin holes from easily increasing in an insulating layer of the wire even in its continuous manufacture for a long time. CONSTITUTION:On a rectangular conductor 1, epoxy.acrylic water dispersion varnish 3 with 3.0 or less turbidity, based on a value of tan theta, is electrodeposited, thererafter to treat this electrocleposition layer by baking 9. An insulating layer is continuously formed in 3.0mum or less thickness in a flat part and further in thickness 1.1 times that in the flat part in a corner part, of the rectangular conductor l.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously and continuously producing a rectangular ultra-thin film insulated wire which has excellent insulating properties and is useful for downsizing and weight reduction of electric equipment.

[0002]

2. Description of the Related Art The group to which the present inventors belong is that the thickness of the flat conductor of the rectangular conductor is 3.0 μm or less, and the thickness of the corner portion is 1.1 times or more that of the flat portion. A rectangular ultra-thin film insulated wire having an ultra-thin film insulating layer has been proposed (JP-A-3-241609). This makes it possible to reduce the size and weight of electric devices by realizing an ultrathin film of the entire insulating film while maintaining the formability of an insulating layer having a required thickness in the corner portion.

In the above, since rolling an insulating round wire results in an insulating layer which is inferior in withstand voltage, heat shock resistance and the like due to residual stress, cracks, etc., there is a problem in forming the ultra thin film type insulating layer. It was proposed that the electrodeposition baking method, which does not occur, be carried out.However, in further research thereafter, when the rectangular ultra-thin film insulated wire was continuously manufactured, the number of pinholes gradually increased in the obtained insulating layer. It turned out that there is a problem in terms of long-term continuous manufacturability.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for manufacturing a flat rectangular ultra-thin film insulated wire in which the number of pinholes in the insulating layer is unlikely to increase even during continuous manufacturing for a long time and the initial manufacturing state can be maintained for a long time. The challenge is to obtain.

[0005]

According to the present invention, an epoxy-acrylic water-dispersed varnish having a turbidity of 3.0 or less based on a tan θ value is electrodeposited on a rectangular conductor and then the electrodeposited layer is baked. 3.0 μm in the flat part of the rectangular conductor after processing
A method for producing a rectangular ultra-thin film insulated wire, characterized by continuously forming an insulating layer having the following thickness and 1.1 times or more of that at a flat portion at a corner portion: Is.

[0006]

[Exemplary Embodiment] The flat conductor has a thickness of 500.
An ultra-thin material having a thickness of less than μm, especially 10 to 200 μm is preferably used. As for the manufacturing method, the number of pinholes is 1
00 / m or less, especially 70 / m or less, especially 50 / m
A continuous system of 20 hours or more and 50 hours or more, while maintaining the following, is adopted.

[0007]

By the above method using the epoxy-acrylic water-dispersed varnish whose turbidity is 3.0 or less based on the tan θ value, the ultrathin insulating layer with a small number of pinholes can be continuously stabilized for a long time. Can be formed. Although the reason for this is unknown, the present inventors have found that the resin component having a small particle size is likely to be electrodeposited preferentially on the basis of the large electrophoretic mobility in the electrodeposition, and therefore the water-dispersed varnish has a large particle size over time. However, the particle size of the resin component in the water-dispersed varnish having the above-mentioned turbidity in the present invention is smaller than that of the conventional resin having a tan θ value of 5 to 7, which is the reason for this. It is believed that this is because an electrodeposition layer based on a resin component having a large particle size is formed with few gaps that are likely to become pinholes.

[0008]

Examples of constituent elements of the present invention: In the production method of the present invention, an epoxy-acrylic water-dispersed varnish having a turbidity of 3.0 or less based on a tan θ value is electrodeposited on a rectangular conductor, and then the electrodeposition layer is formed. 2. In the flat portion of the flat rectangular conductor, the bake treatment is performed.
A rectangular ultra-thin film insulated wire is obtained by continuously forming an insulating layer having a thickness of 0 μm or less and 1.1 times or more of that at a flat portion at a corner portion. The rectangular ultra-thin film insulated wire is illustrated in FIG. 1 is a flat conductor, 13
Is an insulating layer, 11 is its flat portion, and 12 is its corner portion.

As the rectangular conductor, one made of an appropriate material may be used. The rectangular conductor which can be preferably used is made of a metal having good conductivity, and examples thereof include ordinary electrolytic copper, aluminum for electrical use, copper alloy, copper clad aluminum, nickel plated copper and the like.

The size of the rectangular conductor is arbitrary, but the thickness is 50 in view of utilizing the advantages of the ultrathin film insulating layer according to the present invention.
An ultra-thin flat conductor having a thickness of 0 μm or less, preferably 10 to 200 μm, is advantageously used. The width may be appropriately determined according to the purpose of use, but is generally 0.1 to 5 mm, and the aspect ratio is generally about 1: 3 to 1: 100.

The insulating layer is attached to the rectangular conductor by an electrodeposition baking method of a water dispersion varnish. As a result, it is possible to form an ultrathin film type insulating layer while realizing the formation of an insulating layer having a sufficient thickness on the corner portion of the flat conductor. In the case of solution type varnish, the coating film at the corner portion is less likely to flow out due to the surface tension during baking, and the coating film at the corner portion has a thickness of substantially 0 μm even if the coating film is applied to the flat portion with a thickness of 5 μm. Therefore, many pinholes are generated at the corners.

The above water dispersion varnish has a turbidity of tan.
3.0 or less based on the θ value, especially 0.01 to 2.95,
In particular, an epoxy-acrylic water-dispersed varnish of 0.02 to 2.9 is used. As a result, the number of pinholes (JIS
C 3003 compliant) 100 / m or less,
In particular, it is possible to carry out continuous production for 20 hours or more, and especially for 50 hours or more, while maintaining at 70 pieces / m or less, particularly 50 pieces / m or less. The turbidity is based on the tan θ value of the resin component in the water dispersion varnish, and the tan θ value is
For example, a molecular weight distribution measuring device (Shimadzu / Kotaki Co., Ltd., NT-
You can check it in 3). It has been pointed out that there is a correlation between the tan θ value and the average particle size.

The type of the epoxy-acrylic water-dispersion varnish is not particularly limited, and a resin component made of a suitable epoxy-group-containing acrylic resin is dispersed in water by using a stabilizer or the like as necessary. Something is used.
The dispersion medium may be a combination of hydrophilic solvents such as alcohol.

Examples of the above-mentioned epoxy group-containing acrylic resin include the component (a) made of an acrylic monomer having a nitrile group and the like, and the component (b) made of an acrylic monomer having an epoxy group. (A) Component and / or (b) Component (c) consisting of unsaturated organic acid having one or more double bonds capable of reacting with double bond and component (c) at least three kinds are used together. Examples include polymers.

Examples of the acrylic monomer as the component (a) include general formula (a): CH ₂ ═C (R ¹ ) R ² (wherein R ¹ is a hydrogen atom or an alkyl group, R ² is a nitrile group, It is an aldehyde group or a carboxyester group.)
And the like.

Examples of the acrylic monomer as the component (b) include general formula (b): CH ₂ ═C (R ³ ) R ⁴ (wherein R ³ and R ⁴ are a hydrogen atom, an alkyl group, an amide group, N
An alkylamide group, an alkylol group, a glycidyl ether group or a glycidyl ester group, and R ³ , R ⁴
At least one of them is a glycidyl ether group or a glycidyl ester group. ) And the like.

In preparing the copolymer, the component (a),
Each of the components (b) and (c) can be used alone or in combination of two or more. The components that can be preferably used from the viewpoint of heat resistance and the like of the obtained insulating layer are represented by the general formula (a),
The carbon number of R ¹ , R ² , R ³ , R ⁴ and the unsaturated organic acid as the component (c) in (b) is about 30 or less, especially 15 or less.

Specific examples of the component (a) that can be preferably used include acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, propyl acrylate,
Examples thereof include butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, acrolein and the like. The component (a) particularly preferable from the viewpoint of heat resistance of the obtained insulating layer has a total carbon number of 15 or less.

Specific examples of the component (b) that can be preferably used include glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether.

Specific examples of the component (c) that can be preferably used include acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, α-ethylacrylic acid, β-methylcrotonic acid,
Tiglic acid, 2-pentenoic acid, 2-hexenoic acid, 2-heptenoic acid, 2-octenoic acid, 10-undecenoic acid, 9-
Such as octadecenoic acid, cinnamic acid, atropic acid, α-benzylacrylic acid, methylatropic acid, 2,4-pentadienoic acid, 2,4-hexadienoic acid, 2,4-dodecanedienoic acid, and 9,12-octadecadienoic acid. Examples include monobasic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, dibasic acid such as glutaconic acid, muconic acid and dihydromuconic acid, tribasic acid such as 1,2,4-butenetricarboxylic acid, and the like. To be Particularly preferred component (c) is acrylic acid, methacrylic acid, crotonic acid, α-ethylacrylic acid, maleic acid, fumaric acid and the like.

The above copolymer can be appropriately prepared by a known polymerization method such as an emulsion polymerization method, a solution polymerization method and a suspension polymerization method. In that case, the proportion of the component (a) used is generally 1 to 20 mol, preferably 2 to 10 mol, and more preferably 4 to 6 mol per mol of the component (b). Further, the usage ratio of the component (c) is generally 0.01 to 0.2 mol per mol based on the total of the components (a) and (b), and in particular 0.03 to 0.1 mol. .

The above copolymer can also be prepared as styrene or a derivative thereof, or a modified product of diolefin. As the styrene derivative, phenyl group of styrene is one or more kinds such as nitrile group, nitro group, hydroxyl group, amino group, vinyl group, phenyl group, halogen atom, alkyl group, aralkyl group, N-alkylamino group and the like. Examples include those that have been replaced.

Examples of the halogen atom include chlorine and bromine. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group and a butyl group. Examples of the aralkyl group include a benzyl group, α-phenyl ether, β-phenyl ether and the like. Examples of the N-alkylamino group include N-methylamine, N-ethylamine, N-propylamine and the like.

Preferred styrene derivatives for modification include methylstyrene, ethylstyrene, divinylbenzene and chlorostyrene. Preferred diolefins include butadiene, pentadiene, methyl-butadiene and the like.

The modified product can be prepared, for example, by copolymerizing one or two or more modifying agents together in preparing the above-mentioned copolymer. In that case, it is preferable that the modifier is used in an amount of about 2 mol or less for styrene or its derivative and about 1 mol or less for diolefin per mol of the component (a). When the amount of styrene or its derivative used is too large, the resulting insulating layer may have poor flexibility. If the proportion of diolefin used is too large, the copolymer obtained may have a poor softening temperature.

Epoxy / acrylic water-dispersed varnish which can be preferably used is an emulsion polymerization liquid prepared by preparing an epoxy / acrylic copolymer by an emulsion polymerization method, or an epoxy / acrylic copolymer in water together with a surfactant. Although dispersed, the degree of polymerization of the copolymer is preferably 2.0 or less from the viewpoint of obtaining an aqueous dispersion varnish having a turbidity based on the tan θ value of 3.0 or less.

The concentration of the epoxy / acrylic copolymer (resin component) in the water-dispersed varnish is generally 0.1 to 10% by weight, preferably 0.3 to 5% by weight. If the concentration is less than 0.1% by weight, pinholes are likely to occur, and if it exceeds 10% by weight, it becomes difficult to form a good ultrathin film.

The flat rectangular ultra-thin film insulated wire can be produced by introducing a flat rectangular conductor into an epoxy-acrylic water-dispersed varnish for electrodeposition and baking the electrodeposited layer. An example of the manufacturing process is shown in FIG.

In FIG. 1, the electrodeposition treatment is carried out by applying D.O.I. to a cylindrical cathode 5 arranged in an electrodeposition bath 4 containing an epoxy-acrylic water dispersion varnish 3. This is performed while introducing the flat conductor 1 connected to the anode side of the C power source (not shown) through the roll 2 and passing it through. By such an operation, the epoxy-acrylic resin component is deposited on the rectangular conductor with a uniform thickness based on the potential difference between the cathode and the rectangular conductor (anode).

The electrodeposition conditions may be appropriately determined depending on the thickness of the insulating layer to be formed. General conditions are described in D. C
Voltage 5-100V, especially 7-70V, electrodeposition time 0.01
~ 30 seconds, especially 0.03 ~ 15 seconds, varnish temperature 5 ~
The temperature is 40 ° C, especially 10 to 35 ° C. At that time, D. C voltage to A. It is also possible to superimpose the C voltage.

The baking treatment may be carried out by immediately drying the electrodeposition layer after the electrodeposition treatment, or after treating the electrodeposition layer with an organic solvent or the like before drying. In the example of FIG. 1, the treatment with such an organic solvent is performed. This treatment with an organic solvent or the like is intended to effectively fuse the resin component particles in the electrodeposition layer during the baking treatment to form a uniform film with fewer pinholes.

The treatment with an organic solvent or the like can be performed by an appropriate method such as immersing the rectangular conductor having the electrodeposition layer in the treatment liquid, or passing it through the vapor or mist of the treatment liquid. In the example of FIG. 1, the rectangular conductor after the electrodeposition treatment is introduced into the bath 6 containing the treatment liquid 7 and allowed to pass therethrough.

As the above-mentioned organic solvent, those capable of swelling, preferably dissolving, the resin component in the semi-cured state before drying and baking on the rectangular conductor, or in the electrodeposition layer before reaching such a state are preferable. Is used.

Specific examples of the organic solvent include methanol, ethanol, propanol, ethylene glycol,
Monohydric or polyhydric alcohols such as glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether,
Cellosolves such as ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ether glycol monophenyl ether, nitrogen-containing compounds such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. Ionic solvents such as Organic solvents that can be preferably used are N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-.
Examples include pyrrolidone and dimethyl sulfoxide.

In the above, in the present invention, at the outlet of the rectangular conductor in the electrodeposition bath and / or the treatment liquid bath,
For example, a wiping device such as an air wiper or a roller wiper may be provided to remove excess varnish and treatment liquid on the electrodeposition layer. By providing such a removing step, the stability of high-speed processing can be improved. That is, in high-speed electrodeposition treatment, etc., the varnish that has not been electrodeposited on the electrodeposition layer may cause foaming in the baking process and hinder high-speed work. The foaming phenomenon can be prevented, and high-speed work can be stably performed. By the way, it is possible to stably prevent the foaming phenomenon even at a high speed work of about 50 m / min or more.

The baking treatment of the electrodeposition layer is carried out by placing the rectangular conductor provided with the electrodeposition layer in a drying process and a baking process. The drying and baking steps can be carried out via a series of heating devices or via separate heating procedures. In the example shown in FIG. 1, the latter method is adopted.
Is a drying device, and 9 is a baking oven.

The drying process is intended to remove water and treatment liquid in the electrodeposition layer by evaporation. The drying conditions may be appropriately determined depending on the presence or absence of treatment with the treatment liquid, the type of organic solvent in the treatment liquid, and the like. Generally, 60-300 ° C,
Especially, it is dried at a temperature of 100 to 250 ° C.

In the above-mentioned drying process or in the previous stage thereof, steam or steam mixed with air is used for the purpose of promoting evaporation of the liquid or making the resin component forming the electrodeposition layer into a semi-cured state or a completely cured state. It is also possible to add a high temperature treatment therein, for example a treatment at a temperature of 200 to 500 ° C. In the case of the high temperature treatment process, the treatment with the organic solvent can be omitted.

The baking process is intended to cure the resin component forming the electrodeposition layer. The baking temperature may be appropriately determined and is generally 200 to 700 ° C, especially 250 to 60 ° C.
It is 0 ° C.

From the above, as shown in FIG. 2, the flat portion of the rectangular conductor 1 has a flat portion of 3.0 μm or less, preferably 0.5 to 3.
Rectangular ultrathin film insulated wire having an insulation layer 13 having a thickness (11) of 0 μm, particularly 0.8 to 2.0 μm, and 1.1 times or more (12) that at the corner portion in a flat portion. Are continuously formed and wound by the winder 10.

The rectangular ultra-thin film insulated wire of the present invention can be used for various purposes as a coil winding in electric equipment and the like. In that case, in the flat ultra-thin film insulated electric wire of the present invention, a self-fusion layer may be provided on the insulating layer for the purpose of facilitating coil winding work and the like. The self-bonding layer is not required to have an insulating function or a high degree of uniformity in layer thickness. The self-fusion layer can be formed by an appropriate method such as a method of dip-coating the varnish and then squeezing the varnish with a felt or the like.

[0042]

【Example】

Example 1 A copper rectangular conductor having a width of 600 μm and a thickness of 30 μm was introduced on the anode side at a linear velocity of 30 m / min into an electrodeposition apparatus consisting of a vertical furnace to form an electrodeposition layer. Electrodeposition conditions are diameter 6 cm, length 3
A copper cylinder of 0 cm was used as the cathode, the distance between the electrodes was 3 cm, and the electrodeposition voltage D.I. C15V and the varnish temperature were 20 degreeC.

The epoxy-acrylic water-dispersed varnish contains
5 mol of acrylonitrile, 1 mol of acrylic acid, 0.3 mol of glycidyl methacrylate, 760 g of ion-exchanged water,
7.5 g of sodium lauryl sulfate and 0.13 g of sodium persulfate were placed in a flask at room temperature under a nitrogen stream.
After stirring for 5 to 30 minutes, the mixture is heated to 50 to 60 ° C.
The emulsion polymerization liquid obtained by reacting at the temperature of 3 hours was used. The turbidity was 1.0 based on the tan θ value.

Next, the rectangular conductor provided with the electrodeposition layer was replaced with N, N
-Length 1 filled with saturated vapor of dimethylformamide
m, and then treated at 200 ° C., and then baked at 400 ° C. to have an insulating layer thickness of 2 μm at a flat portion and an insulating layer thickness of 2.2 at a corner portion.
A rectangular ultra-thin film insulated wire having a thickness of μm was continuously obtained for 50 hours.

Comparative Example 1 According to the same manner as in Example 1, except that a water-dispersed varnish made of an epoxy-acrylic resin obtained with a reaction time of 4 hours and having a turbidity of 6.0 based on a tan θ value was used. An ultra-thin insulated wire was obtained.

Evaluation Test The number of pinholes per 1 m in the insulating layer of the flat rectangular ultrathin film insulated electric wires obtained in Example 1 and Comparative Example was measured according to JIS C 30.
It measured based on 03. The measurement targets were the production start portion (0 hour), and 10 hours, 20 hours, and 50 hours (production end portion) from the start of production.

The above results are shown in Table 1. The number is 5
It means the range of the number of pinholes that appeared in the test results of one time.

[Table 1]

[0048]

According to the present invention, a rectangular ultra-thin film insulated wire can be continuously and stably produced for a long time while maintaining the initial production state in which the number of pinholes in the ultra-thin insulating layer is small. it can.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an example of a manufacturing process.

FIG. 2 is an enlarged cross-sectional view of an example of a rectangular ultra-thin film insulated wire.

[Explanation of Codes] 1: Rectangular conductor 13: Insulating layer 11: Flat part 12: Corner part 4: Electrodeposition bath 3: Epoxy / acrylic water dispersion varnish 5: Cathode 8: Drying device 9: Baking furnace

Claims (1)

[Claims] 1. The rectangular conductor is formed by electrodepositing an epoxy-acrylic water-dispersed varnish having a turbidity of 3.0 or less based on a tan θ value on the rectangular conductor and baking the electrodeposited layer. Flat thin film insulated wire characterized by continuously forming an insulating layer having a thickness of 3.0 μm or less in the flat portion and 1.1 times or more of that in the flat portion at the corner portion Manufacturing method.