KR20210131637A - Insulation wire - Google Patents

Abstract

The present invention relates to an electrical insulating varnish comprising a polyimide precursor, which is a reaction product of a diamine compound and tetracarboxylic acid or an anhydride of tetracarboxylic acid, wherein a surface tension of the electrical insulating varnish is greater than or equal to 30 dyne/cm and less than or equal to 40 dyne/cm, and a winding manufactured using the same. More specifically, the present invention relates to an electrical insulating wire, an electrical insulating varnish capable of forming an insulating layer having a uniform thickness, and a winding manufactured using the same.

Description

Insulated Wire {INSULATION WIRE}

The present invention relates to an insulated wire, and more particularly, to an insulated varnish having excellent applicability of a flat wire, and a winding manufactured using the same.

Energy efficiency improvement, miniaturization, and long-term reliability improvement of electric devices and parts have been continuously progressed since the use of electricity, and the prismaticization of conductors is inevitable for miniaturization and high efficiency.

As a conductor (core wire) of an insulated wire, a conductor (round wire) having a substantially circular cross section has been used in the past. have.

However, when a conductor to which a voltage is applied becomes square, an electric field is concentrated in the corner portion, the thickness of the insulating film becomes non-uniform, an unnecessary space is formed in the winding state, and a decrease in the space factor occurs, which causes insulation reliability to become a problem.

In the flat winding, the uniformity of the insulating film is important for this reason as well, but it is a difficult problem to make the film thickness uniform compared to the round wire having a round cross section.

Windings are generally manufactured as follows. After the insulating varnish is applied to the conductor surface, an insulating film is formed on the conductor by adjusting the amount of application on the conductor surface with an application die and equalizing the applied insulating varnish surface, and then curing the applied varnish through an oven. Then, the process is repeated several times until the insulating film reaches a predetermined thickness.

The coating die has an opening, and the core wire to which the insulating varnish is applied passes through this opening to remove the excess insulating varnish, thereby adjusting the application amount.

In an insulated wire, since the electrical insulation of an insulated wire is determined by the thin part of an insulated film when the thickness of an insulation film is non-uniform|heterogenous, insulation may become inadequate. Therefore, it is important to make the film thickness uniform. As a coating die, the thing of the shape of the opening part at the time of planar view is substantially similar to the cross-sectional shape of a conductor is used generally.

As shown in Fig. 1, in a flat wire, after passing through the die, the insulation varnish tends to flow to the edge of the flat conductor due to the surface tension of the insulation varnish until it hardens, and the edge is swollen, so-called dogbone shape. of insulating film tends to be formed.

In order to make the thickness of the insulating film uniform, a coating die having a shape different from that of the conductor is sometimes used, but as the type of varnish is changed, a dog-bone phenomenon occurs, making it difficult to use in general.

In addition, in order to make the thickness of the insulating film uniform, the viscosity of the varnish is 20,000 cPs or more. However, if the varnish viscosity is increased, the flow of varnish is not good when supplying and recovering varnish to the varnish coating part, so the varnish overflows in the coating part or a high-viscosity motor has to be used. There is a problem with change.

Therefore, there is a need for research on an insulating varnish that can easily form an insulating coating having a uniform thickness without changing equipment.

Patent Document 1: Korean Patent Publication No. 10-2005-0070290

The technical problem to be solved by the present invention is to provide an insulating varnish that is easy to form an insulating coating of a uniform thickness without changing equipment, and an insulating wire manufactured using the same, and a winding having a uniform thickness of the insulating film.

As a means for solving the above technical problem, the present invention provides an insulated wire.

More specifically, the present invention provides an insulating varnish comprising a polyimide precursor, which is a reaction product of a diamine compound and tetracarboxylic acid or anhydride of tetracarboxylic acid, wherein the surface tension of the insulating varnish is 30 dyne/cm or more to 40 dyne/cm cm or less.

In addition, the present invention provides an insulating varnish that has a viscosity of 10 poise or more to 100 poise or less of the insulating varnish.

In addition, the present invention provides an insulating varnish wherein the polyimide precursor has a weight average molecular weight of 20,000 g/mol or more to 500,000 g/mol or less.

In addition, the present invention provides an insulating varnish comprising a polyimide precursor such that the insulating varnish has a solid content concentration of 10 wt% or more to 50 wt% or less in the insulating varnish.

In the present invention, the diamine compound is 2,2-di(p-aminophenyl)-6,6'-bisbenzooxazole, m-phenylenediamine, 4,4'-diaminodiphenylpropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl ether, benzidine, 4,4"-diamino p-terphenyl, p-bis(2-methyl-4-aminopentyl)benzene, 1,5-diaminonaphthalene, 2,4-diaminotoluene, m-xylene-2,5-diamine, m-xylene It provides an insulating varnish that is one or more selected from the group consisting of diamine, piperazine, methylenediamine, ethylenediamine and tetramethylenediamine.

In the present invention, the tetracarboxylic acid or anhydride of tetracarboxylic acid is pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, benzene-1,2 ,3,4-tetracarboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 2, 2",3,3"-p-terpenirtetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride water, bis(2,3-dicarboxyphenyl) methane dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl) sulfone dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride. Phenanthrene-1,2,7,8-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride and pyrazine-2,3,5,6-tetracarboxylic acid It provides an insulating varnish that is one or more selected from the group consisting of dianhydrides.

In addition, the present invention provides an insulating varnish that further includes an additive capable of reducing the surface tension of the insulating varnish.

In addition, the present invention is a conductor; and an insulating layer provided to surround the outer periphery of the conductor, wherein the insulating layer is formed using the above-described insulating varnish.

In addition, the present invention provides a winding that the winding is a flat winding.

The insulating varnish included in the insulated wire according to the present invention can form a uniform insulating layer thickness without equipment change.

The accompanying drawings are intended to explain the contents of the present invention in more detail to those skilled in the art, but the technical spirit of the present invention is not limited thereto.
1 is a view showing a winding in which a dogbone shape is formed.
2 is a view showing a winding according to an embodiment.
3 is a view showing a winding for measuring the uniformity of the film.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description below is only for specifying the embodiments, and is not intended to limit or limit the scope of rights according to the present invention. What a person of ordinary skill in the art related to the present invention can easily infer from the detailed description and embodiments of the invention should be construed as belonging to the scope of the present invention.

Although the terms used in the present invention have been described as general terms widely used in the technical field related to the present invention, the meaning of the terms used in the present invention is the intention of a technician in the relevant field, the emergence of new technology, examination standards or precedents. It may vary depending on Some terms may be arbitrarily selected by the applicant, and in this case, the meaning of the arbitrarily selected terms will be described in detail. Terms used in the present invention should be interpreted as meanings reflecting the overall context of the specification, not just dictionary meanings.

Terms such as 'consisting of' or 'comprising' used in the present invention should not be construed as necessarily including all of the components or steps described in the specification, and if some components or steps are not included, And when additional components or steps are further included, it should also be construed as intended from the term.

Hereinafter, the present invention will be described in detail.

One embodiment of the present invention provides an insulated wire.

More specifically, the present invention provides an insulating varnish containing a polyimide precursor, which is a reaction product of a diamine compound and tetracarboxylic acid or an anhydride of tetracarboxylic acid, contained in the insulated wire, wherein the surface tension of the insulating varnish is It provides an insulating varnish of 30 dyne / cm or more to 40 dyne / cm or less.

In an exemplary embodiment of the present invention, the insulating varnish includes a polyimide precursor, which is a reaction product of a diamine compound and tetracarboxylic acid or an anhydride of tetracarboxylic acid. Specifically, a diamine compound and tetracarboxylic acid or an anhydride of tetracarboxylic acid are synthesized through a ring-opening polyaddition-dehydration cyclization reaction, and the polyimide precursor may also be defined as polyamic acid (PAA). have.

In one embodiment of the present invention, the insulating varnish includes a polyimide precursor, which is a reaction product of a diamine compound and tetracarboxylic acid or an anhydride of tetracarboxylic acid, and the surface tension of the insulating varnish is 30 dyne/cm or more It is sufficient if it is 40 dyne/cm or less, and the polyimide precursor which is a reaction product of a diamine compound and tetracarboxylic acid or an anhydride of tetracarboxylic acid is not limited.

Specifically, the diamine compound is, 2,2-di(p-aminophenyl)-6,6'-bisbenzoxazole, m-phenylenediamine, 4,4'-diaminodiphenylpropane, 2,2 -bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl ether, benzidine, 4,4"-diamino p-ter Phenyl, p-bis (2-methyl-4-aminopentyl) benzene, 1,5-diaminonaphthalene, 2,4-diaminotoluene, m-xylene-2,5-diamine, m-xylene diamine, pipette It may be one or two or more selected from the group consisting of razine, methylenediamine, ethylenediamine, and tetramethylenediamine.

In addition, the tetracarboxylic acid or anhydride of tetracarboxylic acid is pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, benzene-1,2,3,4 -tetracarboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 2,2",3 ,3"-p-terpenirtetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, bis( 2,3-dicarboxyphenyl) methane dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl) sulfone dianhydride, 1,1- Bis(2,3-dicarboxyphenyl)ethane dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride. Phenanthrene-1,2,7,8-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride and pyrazine-2,3,5,6-tetracarboxylic acid It may be one or two or more selected from the group consisting of dianhydrides.

In one embodiment of the present invention, in the insulating varnish, the tetracarboxylic acid or anhydride of tetracarboxylic acid and the diamine compound are in a molar ratio of 1.05:0.95 to 0.95:1.05, more preferably 1.02:0.98 to 0.98:1.02 It may include a polyimide precursor, which is a reactant formulated in a molar ratio of .

In one embodiment of the present invention, the insulating varnish may further include an additive capable of reducing the surface tension of the insulating varnish.

Specifically, an additive capable of lowering the surface tension may be further included in order to control the surface tension, and for the control of the surface tension, a method for controlling the surface tension other than the additive is not limited.

In one embodiment of the present invention, the additive capable of lowering the surface tension may be a fluidity modifier, and specifically, BYK 300, BYK 301, BYK 335, BYK 302, BYK 331, BYK 332, BYK 306, BYK 307, BYK 333, BYK 337, BYK 341, BYK 330, BYK 344, BYK 320, BYK 325, BYK 370, BYK 371, BYK 373, BYK 377, BYK 301, BYK 315, BYK 322, BYK 323, BYK 401, etc. It may be an additive that can control the surface tension of other modified polydimethylsiloxane-based, silanes, fluororesin, and the like, but is not limited thereto.

In one embodiment of the present invention, the additive may be BYK 410.

In an exemplary embodiment of the present invention, when the additive is BYK 410, the content of the additive is 0.4 wt% or more to 1 wt% or less, based on the total weight of the solid content in the insulating varnish.

In one embodiment of the present invention, the degree of decrease in surface tension may be different depending on the type of additive, and the type and content of the additive in the range of 30 dyne/cm or more to 40 dyne/cm or less of the surface tension of the insulating varnish can be adjusted

In an exemplary embodiment of the present invention, the reaction of the diamine compound and tetracarboxylic acid or anhydride of tetracarboxylic acid may be performed in a solvent. Specifically, the reaction of the diamine compound and tetracarboxylic acid or anhydride of tetracarboxylic acid may be synthesized by polycondensation under anhydrous conditions in a solvent at a temperature of 0°C or higher to 100°C or lower.

In one embodiment, the solvent is N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetramethyl urea, hexaethyl phosphate triamide, Polar organic solvents, such as (gamma)-butyrolactone; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cycloxanone; esters such as methyl acetate, ethyl acetate, butyl acetate, and diethyl oxalate; ethers such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, and tetrahydrofuran; halogenated hydrocarbons such as dichloromethane and chlorobenzene; hydrocarbons such as hexane, heptane, benzene, toluene, and xylene; phenols such as cresol and crolephenol; tertiary amines such as pyridine; and the like, but are not limited thereto, and each of the solvents may be used alone or in combination of two or more. In one embodiment of the present invention, the amount of the solvent used is an amount necessary to uniformly dissolve or disperse at least each component such as a polyimide-based resin, and is not limited thereto.

In one embodiment of the present invention, the viscosity of the insulating varnish is 10 poise or more to 100 poise or less. When it has a viscosity in the above range, it is possible to form an insulating layer of a uniform thickness without changing the coating equipment in order to use the high-viscosity varnish.

In an exemplary embodiment of the present invention, the weight average molecular weight of the polyimide precursor is 20,000 g/mol or more to 500,000 g/mol or less. If the weight average molecular weight of the polyimide precursor is less than 20,000 g / mol, cracks may occur after film coating, resulting in deterioration of electrical and mechanical properties of the product, and the weight average molecular weight of the polyimide precursor exceeding 500,000 g / mol In this case, the viscosity of PAA rises to more than 100 Poise, and structural change of the facility is required.

In one embodiment, the insulating varnish includes a polyimide precursor such that the concentration of solids in the insulating varnish is 10 wt% or more to 50 wt% or less. When the concentration of the solid content is less than 10% by weight, it is difficult to secure the insulation thickness of the product.

In addition, one embodiment of the present invention is a conductor; and an insulating layer provided to surround the outer periphery of the conductor, wherein the insulating layer is formed using the insulating varnish.

In the present invention, the conductor may be made of a conductive metal such as copper or aluminum having high electrical conductivity. In addition, the thickness and shape of the conductor can be manufactured in various ways according to the use of the insulated wire including the same and the KS standard (KS C3107).

2 is a view showing a winding according to an embodiment. Specifically, the winding 100 according to an exemplary embodiment of the present invention includes a conductor 101 having a flat shape; and an insulating layer 102 provided to surround the outer periphery of the conductor.

In the present invention, the insulating layer provided to surround the outer periphery of the conductor is formed using the above-described insulating varnish.

In one embodiment of the present invention, the winding is a flat winding. The insulating varnish according to an exemplary embodiment of the present invention may provide an insulating layer having a uniform thickness in which a dogbone phenomenon does not occur even in a flat winding.

In the present invention, the insulating varnish may be equally applied as long as it does not contradict the matters mentioned in the above-mentioned varnish.

In the present invention, the winding may be manufactured by a generally used manufacturing method, except for using the above-described varnish for the varnish. For example, it can be prepared by coating on a conductor.

Hereinafter, examples will be given to describe the present invention in detail. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention is not to be construed as being limited to the embodiments described below. The embodiments of the present specification are provided to more completely explain the present invention to those of ordinary skill in the art.

[Example 1]

Quantitative mixing of pyromellitic dianhydride (PMDA) and 4,4'-diaminodiphenyl ether (ODA) in a flask equipped with a stirrer, reflux cooling tube, nitrogen inlet tube and thermometer (molar ratio 1.02:0.98 to 0.98:1.02) ), N-methyl-2-pyrrolidone (NMP) was compounded so that the solid content concentration was 15 wt%, and then reacted at room temperature for 12 hours to prepare an insulating varnish.

The surface tension was adjusted to 30 dyne/cm (1 wt% relative to the solid content) by using an additive (BYK 410) in the insulating varnish.

[Examples 2 and 3]

The insulating varnish was applied in the same manner as in Example 1, except that in Example 1, the surface tension was prepared at 35 dyne/cm (0.5 wt% relative to solid content) and 40 dyne/cm (0.4 wt% relative to solid content), respectively, using additives. prepared.

[Comparative Examples 1 to 3]

Using the additive in Example 1, the surface tension was 28 dyne / cm (1.3 wt % relative to solid content), 42 dyne / cm (0.2 wt % relative to solid content) and 46 dyne / cm (0.1 wt % relative to solid content), respectively, except for those prepared and an insulating varnish was prepared in the same manner as in Example 1.

[Experimental example]

The baking temperature and time of the insulating varnish was performed by passing the inside of an oven at about 120° C. to 500° C. for 5 seconds to 20 seconds. The coating was repeated 10 to 15 times.

Using the insulating varnish prepared in Examples 1 to 3 and Comparative Examples 1 to 3, windings were manufactured as shown in Table 1 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Surface tension of insulating varnish
(dyne/cm) 30 35 40 28 42 46 thickness
(μm) 50 49 49 48 50 49 filmization O O O O O O Coating film uniformity 0.98 1.01 1.01 0.78 0.76 0.63

In Table 1 above, the surface tension of the insulating varnish was measured using a surface tension meter of SEO Corporation.

In Table 1, the filming test was performed in a vacuum oven at 200°C after heat treatment at 80°C for 10 minutes, 150°C for 10 minutes, 200°C for 10 minutes, and 250°C for 10 minutes to check whether the insulating varnish can be filmed. After drying time, it was visually confirmed. When the film was normally formed, "O" was indicated, and when the film was not formed normally, "NG" was indicated.

In Table 1, the film uniformity was measured based on the following formula by measuring the thickness of the region shown in FIG. 3 .

Referring to Table 1, in the case of Examples 1 to 3, wherein the surface tension of the insulating varnish containing the polyimide precursor is in the range of 30 dyne/cm or more to 40 dyne/cm or less, the surface tension of the insulating varnish is less than 30 dyne/cm to 40 dyne Compared to Comparative Examples 1 to 3 exceeding /cm, the uniformity of the film was close to 1, and it was confirmed that a uniform insulating layer was formed.

The above description of the present application is for illustration, and those of ordinary skill in the art to which the present application pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present application is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present application.

100: winding
101: conductor
102: insulating layer

Claims (9)

An insulating varnish comprising a polyimide precursor, which is a reaction product of a diamine compound and tetracarboxylic acid or anhydride of tetracarboxylic acid, the insulating varnish comprising:
The surface tension of the insulating varnish is an insulating varnish of 30 dyne / cm or more to 40 dyne / cm or less.
The method of claim 1,
The insulating varnish has a viscosity of 10 poise or more to 100 poise or less of the insulating varnish.
The method of claim 1,
The polyimide precursor has a weight average molecular weight of 20,000 g/mol or more to 500,000 g/mol or less of an insulating varnish.
The method of claim 1,
The insulation varnish, the insulation varnish comprising a polyimide precursor such that the solid content concentration in the insulation varnish is 10% by weight or more and 50% by weight or less.
The method of claim 1,
The diamine compound is 2,2-di(p-aminophenyl)-6,6'-bisbenzoxazole, m-phenylenediamine, 4,4'-diaminodiphenylpropane, 2,2-bis[ 4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl ether, benzidine, 4,4"-diamino p-terphenyl, p -bis(2-methyl-4-aminopentyl)benzene, 1,5-diaminonaphthalene, 2,4-diaminotoluene, m-xylene-2,5-diamine, m-xylene diamine, piperazine, methylene An insulating varnish that is one or more selected from the group consisting of diamine, ethylenediamine and tetramethylenediamine.
The method of claim 1,
The tetracarboxylic acid or anhydride of tetracarboxylic acid is pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, benzene-1,2,3,4-tetra Carboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 2,2",3,3 "-p-terpenirtetracarboxylic dianhydride, 2,2-bis (2,3-dicarboxyphenyl) -propane dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, bis (2, 3-dicarboxyphenyl) methane dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl) sulfone dianhydride, 1,1-bis( 2,3-dicarboxyphenyl) ethane dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride. Phenanthrene-1,2,7,8-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride and pyrazine-2,3,5,6-tetracarboxylic acid An insulating varnish that is one or two or more selected from the group consisting of dianhydrides.
The method of claim 1,
The insulating varnish further comprises an additive capable of lowering the surface tension of the insulating varnish.
conductor; and
Including an insulating layer provided to surround the outer periphery of the conductor,
The insulating layer is a winding formed using the insulating varnish according to any one of claims 1 to 7.
9. The method of claim 8,
The winding is a flat winding.

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