KR101708498B1 - Insulated Wire - Google Patents

Abstract

The insulated electric wire of the present invention comprises a conductor wire; And at least three insulating coating layers formed on the outside of the conductor line, wherein the polyimide imide resin layer has a thickness of 20 to 40% of the total insulating coating layer and is the outermost layer of the insulating coating layer; A polyamide imide resin layer having a film thickness of 30 to 50% of the total insulating coating layer and containing inorganic particles which are in contact with the outermost layer and are a lower layer; And a polyamide imide resin layer having a film thickness of 20 to 30% of the total insulating coating layer and including an adhesion promoting agent as a lowermost layer of the insulating coating layer. The insulating coating layer of such an insulated wire is excellent in heat resistance and excellent in film adhesion.

Description

Insulated Wire

The present invention relates to an insulated wire for a wire having excellent heat resistance.

Recently, as the size and weight reduction tendency of electrical or electronic devices has increased, a smaller and lighter motor with higher performance has been required. In order to satisfy such a requirement, it has been necessary to increase the number of windings for winding the circumference of the motor core with an insulated wire. The demand for a motor using a divided core using a concentrated winding type winding method in a distributed winding type has been increased in order to wind the winding more in a narrow space. For this purpose, a greater amount of insulated wires must be forced into the core slot. As a result, excessive current flowed through the motor, and excessive current required heat resistance of the motor. Excessive current also caused the insulation coating to be destroyed. In particular, the use environment may be more serious when exposed to a high temperature environment such as an automobile engine room.

Generally, such a motor has usually used an insulated wire having good thermal properties formed by coating and baking a coating material for coating a polyamide imide having good mechanical strength on a conductor. Today, however, there is a demand for more powerful, yet smaller, and lighter-weight motors. In order to satisfy these requirements, it is necessary to further increase the number of windings of the insulated wire, so that the insulating coating of the polyamide-imide base having good heat resistance may be damaged. In order to further increase the heat resistance of the insulating coating, there is a case where polyimide insulated wires are used. In this case, since the imidization proceeds at the time of manufacturing the insulated wires, it is pointed out that water is generated as a by- come.

Accordingly, Korean Patent No. 0483712 discloses a polyimide insulated wire which eliminates byproducts during the manufacture of windings. However, when applied to a concentric winding type motor such as the present, insufficient film adhesion and lack of lubricity cause insulator damage It is somewhat unreasonable to apply it. Although attempts have been made to increase the heat resistance by dispersing an inorganic material such as silica in an insulating material resin, the dispersibility of the inorganic material is low and it is difficult to disperse the inorganic material into the insulating material at a nano size, that is, 100 nm or less.

The present invention aims to provide an insulated electric wire suitable for winding.

The insulated electric wire of the present invention comprises a conductor wire; And at least three insulating coating layers formed on the outside of the conductor line, wherein the polyimide imide resin layer has a thickness of 20 to 40% of the total insulating coating layer and is the outermost layer of the insulating coating layer; A polyamide imide resin layer having a film thickness of 30 to 50% of the total insulating coating layer and containing inorganic particles which are in contact with the outermost layer and are a lower layer; And a polyamide imide resin layer having a film thickness of 20 to 30% of the total insulating coating layer and including an adhesion promoting agent as a lowermost layer of the insulating coating layer.

Such an inorganic particle may be an inorganic particle selected from the group consisting of an inorganic particle having a core-shell type having an amino group or a carboxyl group and a metal oxide surface-modified with a coupling agent, or a mixture thereof. Particularly, the core-shell type inorganic particles having an amino group or a carboxyl group are preferably core-shell type silica having an amino group or a carboxyl group. The metal oxide is preferably magnesium oxide, calcium oxide, scandium oxide, barium oxide, titanium dioxide and zirconium dioxide.

The inorganic particles may be used in an amount of 5 to 25% by weight based on the polyamide imide resin layer containing the inorganic particles.

The adhesion-promoting agent used in the insulated wire of the present invention may be used in an amount of 0.05 to 2% by weight based on the polyamide-imide resin layer containing the adhesion-promoting agent.

The insulating coating layer of the insulated electric wire of the present invention is excellent in heat resistance and excellent in film adhesion.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. No.
1 is a cross-sectional view of an insulated wire having three layers of insulating layers according to one embodiment.

Hereinafter, the present invention will be described in detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

The insulated electric wire of the present invention comprises a conductor wire; And at least three insulating coating layers formed on the outside of the conductor line, wherein the polyimide imide resin layer has a thickness of 20 to 40% of the total insulating coating layer and is the outermost layer of the insulating coating layer; A polyamide imide resin layer having a film thickness of 30 to 50% of the total insulating coating layer and containing inorganic particles which are in contact with the outermost layer and are a lower layer; And a polyamide imide resin layer having a film thickness of 20 to 30% of the total insulating coating layer and including an adhesion promoting agent as a lowermost layer of the insulating coating layer.

Referring to FIG. 1, the insulated electric wire of the present invention includes at least three insulated coating layers. According to a temporary example, the insulated electric wire 10 having three insulated coating layers is a layer of the lowest layer A polyamideimide resin layer 12 containing an adhesion promoting agent, a polyamide imide resin layer 13 containing an inorganic particle as a layer thereon, and a polyamideimide resin layer 14 as an outermost layer.

The polyamide imide resin used in the insulating coating layer of the present invention may be an aromatic diisocyanate, a polyamide imide resin prepared by solution thermal polymerization method of diamines and polybasic acid anhydrides in an organic solvent. At this time, the content of the acid anhydride used is preferably 0.7 to 1.3, more preferably 0.8 to 1.2, based on the diisocyanate. When the content of the acid anhydride relative to the diisocyanate is less than 0.7 or more than 1.3, the physical properties of the general polyamide imide do not appear.

Specific examples of the aromatic diisocyanate include diphenylmethane-4,4'-diisocyanate, diphenylmethane-3,3'-diisocyanate, diphenylmethane-3,4'-diisocyanate, diphenylether- , 4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene- m-xylylene diisocyanate, p-xylylene diisocyanate, and the like, but are not limited thereto, and they may be used alone or as a mixture thereof. Of the diisocyanate compounds, diphenylmethane-4, 4'-diisocyanate is preferable from the viewpoints of ease of purchase and cost.

As the acid component of the polyamideimide, any acid conventionally used can be used. Examples of preferred acids include, but are not limited to, trimellitic acid such as tribasic acid and the like, trimellitic acid anhydride, derivatives of trimellitic chloride or trimellitic acid, and the like. Of these, trimellitic anhydride is preferred from the viewpoints of ease of purchase and cost. Examples of the organic solvent include N-methyl-2-pyrrolidone, dimethylacetamide and N, N-dimethylformamide, and N-methyl-2-pyrrolidone is mainly used.

The polyamide-imide resin layer 14 as the outermost layer preferably has a film thickness of 20 to 40% of the total insulating coating layer.

The polyamide-imide resin layer 13 containing the inorganic particles, which is a lower layer in contact with the outermost layer of the present invention, preferably has a film thickness of 30 to 50% of the total insulating coating layer. The increase effect can not be observed, and when it is more than 50%, the film insufficiency of the insulating film is lowered.

There may arise a problem of dispersibility which occurs when an inorganic material is dispersed in a polyamide imide resin. To this end, a core-shell type inorganic particle having a functional group capable of reacting with a polyamideimide polymer main chain and a surface modification The metal oxide in the polyamide imide can be controlled to have a nano size of 100 nm or less by dispersing the mixed metal oxide in the polyamide imide. As the core-shell type inorganic particles having a functional group capable of reacting with the polyamideimide polymer main chain, core-shell type inorganic particles having an amino group or a carboxyl group can be used. Particularly, the core-shell type inorganic particles having an amino group or a carboxyl group are not particularly limited, but a core-shell type silica having an amino group or a carboxyl group is preferably used. The metal oxide is preferably magnesium oxide, calcium oxide, scandium oxide, barium oxide, titanium dioxide and zirconium dioxide.

The inorganic particles may be used in an amount of 5 to 25% by weight based on the polyamide imide resin layer containing the inorganic particles. When the amount is less than 5% by weight, the effect of the inorganic material is not exhibited. The acidity deteriorates and the effect of the inorganic material deteriorates, and the film becomes brittle, so that the film scratch resistance of the insulating film is deteriorated.

The lowest layer (12) of the insulating coating layer of the present invention has a thickness of 20 to 30% of the total thickness of the polyamide imide resin layer including the adhesion promoting agent as compared with the entire insulating coating layer.

Examples of the adhesion promoter used in the insulated electric wire of the present invention include melamine resins such as butoxy melamine resins, amines such as trialkylamine, mercaptans such as mercaptobenzimidazole, and polycarbodiimide resins. It is not limited. Such an adhesion promoting agent may be used in an amount of 0.05 to 2% by weight based on the polyamide imide resin layer containing the adhesion promoting agent. When the amount of the adhesion-promoting agent is less than 0.05 wt%, the effect of improving the adhesion can not be obtained. When the amount of the adhesion-improving agent is more than 2 wt%, the adhesion is decreased due to excessive adhesion-improving agent.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention may be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

Example

Preparation Example 1. Synthesis of polyamideimide (PAI 1)

510.0 parts by weight of N-methyl pyrrolidone was added to a four-necked flask equipped with a stirrer and a condenser, which had been well dried at room temperature, and 201 parts by weight of trimellitic dianhydride was added thereto to start stirring . Thereafter, 250 parts by weight of diphenylmethane-4, 4'-diisocyanate (MDI) was added and the temperature was gradually raised from 80 ° C to 140 ° C to synthesize a polyamideimide resin.

Production Example 2. Inorganic material dispersion Polyamideimide synthesis (PAI 2)

510.0 parts by weight of N-methyl pyrrolidone was added to a four-necked flask equipped with a stirrer and a condenser, which had been well dried at room temperature, and 201 parts by weight of trimellitic dianhydride was added thereto to start stirring . Thereafter, 250 parts by weight of diphenylmethane-4, 4'-diisocyanate (MDI) was added and the temperature was gradually raised from 80 ° C to 140 ° C to synthesize a polyamideimide resin. The core-shell type silica having an amino group was dissolved in NMP, mixed with a metal oxide having a surface size of about 70 nm modified with a silane coupling agent, and sonicated to prepare a nanosilica-metal oxide solution Were prepared. A nanosilica-metal oxide solution was added to the polyamideimide solution thus synthesized so that 10 parts by weight of silica and a metal oxide were added to 100 parts by weight of the polyamide imide resin.

Production Example 3. Inorganic material dispersion Polyamideimide synthesis (PAI 3)

510.0 parts by weight of N-methyl pyrrolidone was added to a four-necked flask equipped with a stirrer and a condenser, which had been well dried at room temperature, and 201 parts by weight of trimellitic dianhydride was added thereto to start stirring . Thereafter, 250 parts by weight of diphenylmethane-4, 4'-diisocyanate (MDI) was added and the temperature was gradually raised from 80 ° C to 140 ° C to synthesize a polyamideimide resin. The core-shell type silica having an amino group is dissolved in NMP and mixed with a metal oxide having a surface size of about 70 nm modified with a silane coupling agent and subjected to sonication to prepare a nanosilica- Prepared. A nanosilica-metal oxide solution was added to the polyamideimide solution thus synthesized so that 20 parts by weight of silica and a metal oxide were added to 100 parts by weight of the polyamide imide resin.

Production example 4. Synthesis of polyamideimide with adhesion promoter (PAI 4)

510.0 parts by weight of N-methyl pyrrolidone was added to a four-necked flask equipped with a stirrer and a condenser, which had been well dried at room temperature, and 201 parts by weight of trimellitic dianhydride was added thereto to start stirring . Thereafter, 250 parts by weight of diphenylmethane-4, 4'-diisocyanate (MDI) was added and the temperature was gradually raised from 80 ° C to 140 ° C to synthesize a polyamideimide resin. To 100 parts by weight of the synthesized polyamide-imide resin, 0.1 part by weight of butylated melamine resin was stirred.

Production example 5. Synthesis of polyamideimide including adhesion promoter (PAI 5)

510.0 parts by weight of N-methyl pyrrolidone was added to a four-necked flask equipped with a stirrer and a condenser, which had been well dried at room temperature, and 201 parts by weight of trimellitic dianhydride was added thereto to start stirring . Thereafter, 250 parts by weight of diphenylmethane-4, 4'-diisocyanate (MDI) was added, and the temperature was gradually raised from 80 ° C to 140 ° C to synthesize a polyamideimide resin. To 100 parts by weight of the synthesized polyamide-imide resin, 0.5 part by weight of butylated melamine resin was stirred.

Production example 6. Synthesis of polyamideimide with adhesion promoter (PAI 6)

510.0 parts by weight of N-methyl pyrrolidone was added to a four-necked flask equipped with a stirrer and a condenser, which had been well dried at room temperature, and 201 parts by weight of trimellitic dianhydride was added thereto to start stirring . Thereafter, 250 parts by weight of diphenylmethane-4, 4'-diisocyanate (MDI) was added and the temperature was gradually raised from 80 ° C to 140 ° C to synthesize a polyamideimide resin. One part by weight of butylated melamine resin was stirred with respect to 100 parts by weight of the synthesized polyamide-imide resin.

Example 1

A polyamide-imide resin obtained from PAI 5 was coated on a flat oxygen-free copper having a corner radius R of 0.5 mm (thickness x width) and dried by heating to form an 8 mu m insulating film. A polyamide imide resin dispersed with an inorganic material obtained from PAI 2 was coated on the mid resin and heated and dried to form an insulating film having a thickness of 16 탆. Polyimide imide resin obtained from PAI 1 was further coated thereon and dried to form an insulating film having a thickness of 16 mu m to obtain a rectangular insulating wire having an insulating film thickness of 40 mu m.

Examples 2-10

Each of Examples 2-10 was prepared in the same manner as in Example 1, except for the components and ratios shown in Table 1 below.

Comparative Example 1-2

Comparative Example 1-2 was prepared in the same manner as in Example 1, except that the components and ratios shown in Table 1 were used.

Example Comparative Example One 2 3 4 5 6 7 8 9 10 One 2 substratum
(탆) 8
PAI 5 12
PAI 5 16
PAI 5 12
PAI 5 12
PAI 5 16
PAI 5 8
PAI 5 12
PAI 5 12
PAI 4 12
PAI 6 4
PAI 5 12
PAI 5 Middle layer
(탆) 16
PAI 2 16
PAI 2 16
PAI 2 12
PAI 2 20
PAI 2 12
PAI 2 20
PAI 2 16
PAI 2 16
PAI 2 16
PAI 2 16
PAI 2 8
PAI 2 Upper layer
(탆) 16
PAI 1 12
PAI 1 8
PAI 1 16
PAI 1 8
PAI 1 12
PAI 1 12
PAI 1 12
PAI 1 12
PAI 1 12
PAI 1 20
PAI 1 20
PAI 1

Test example. Property measurement

Thinning test layer

A specimen of about 50 cm in length of the insulated electric wire prepared in Examples 1-10 and Comparative Example 1-2 was fixed to the end of the thinning tester and then a load of 800 g was applied to one end. After removing the film above and below the specimen, the tester was operated. The number of revolutions when the film was cut was measured and shown in Table 2 below.

Coating imperfection

In order to make the specimens of about 40 cm in length of the insulated wires prepared in Examples 1-10 and 1-2, into an elongated S-shape, the mandrel was bent 180 ° in both directions using a mandrel hoisting test equipment, Cracks and / or peeling were observed. The minimum mandrel diameter d (mm), which was not cracked nor peeled, proceeding three times for thickness and width, respectively, are reported in Table 2 below.

Softening

One specimen having a length of about 20 cm of the insulated wire prepared in Examples 1-10 and Comparative Example 1-2 was taken and a smooth steel ball having a surface of 1.6 mm in diameter was placed on the surface of the butterfly and a load of 1000 g was applied thereon This was placed in a constant-temperature bath and the results are shown in Table 2 below.

Dielectric breakdown voltage

Specimens of the insulated wires prepared in Examples 1-10 and Comparative Examples 1-2 were prepared and subjected to the metal foil method according to JIS C 3003. Table 2 shows the average of five specimens.

Residual deterioration rate

Specimens of the insulated wires prepared in Examples 1-10 and 1-2 were prepared and kept in an oven at 220 캜 for 7 days and then subjected to a metal foil method according to JIS C 3003. Table 2 shows the average of five specimens. The percentage value in Table 2 below means a comparison value with an insulation breakdown voltage.

Example Comparative Example One 2 3 4 5 6 7 8 9 10 One 2 Chloride (times) 74 79 83 78 79 84 73 71 73 77 59 80 Coating imperfection 1d 1d 1d 1d 1d 1d 1d 1d 1d 1d 1d 2d Softening (℃) 414 411 409 410 415 407 417 423 416 407 410 381 Dielectric breakdown voltage
(V) 6700 6850 6900 6540 7120 6670 7090 7160 6790 6910 5920 5860 Residual deterioration rate
(V) 5540
82.7% 5690
83.1% 5750
83.3% 5330
81.5% 6070
85.3% 5500
82.5% 6000
84.6% 6170
86.2% 5660
83.4% 5720
82.8% 3690
62.3% 3330
56.8%

Example 1-10 showed good test results. In particular, it exhibited excellent heat resistance with an internal softening temperature of 400 ° C or higher and a deterioration residual rate of 80% or higher. On the other hand, in Comparative Example 1, the ratio of PAI 5, which is a polyamide imide resin layer containing an adhesion promoting agent, is low and thus does not have proper adhesion. Comparative Example 2 shows a low ratio of PAI 2, Heat resistance is poor.

10: insulated wire 11: conductor wire
12: Polyamideimide resin layer including adhesion promoter
13: Polyamide imide resin layer containing inorganic particles
14: Polyamideimide resin layer

Claims (6)

Conductor wire; And at least three insulating coating layers formed on the outside of the conductor line,
A polyamide imide resin layer having a film thickness of 20 to 40% of the total insulation coating layer and being the outermost layer of the insulation coating layer;
A polyamide imide resin layer having a film thickness of 30 to 50% of the total insulating coating layer and containing inorganic particles which are in contact with the outermost layer and are a lower layer; And
A polyamide imide resin layer having a film thickness of 20 to 30% of the total insulation coating layer and including an adhesion promoting agent as a lowermost layer of the insulating coating layer,
Wherein the inorganic particles are a mixture of a core-shell type inorganic particle having an amino group or a carboxyl group and a metal oxide surface-modified with a coupling agent, based on the total weight of the polyamide imide resin layer containing the inorganic particles, ≪ / RTI > by weight. delete The method according to claim 1,
Wherein the core-shell type inorganic particle having an amino group or a carboxyl group is a core-shell type silica having an amino group or a carboxyl group. The method according to claim 1,
Wherein the metal oxide is at least one compound selected from the group consisting of magnesium oxide, calcium oxide, scandium oxide, barium oxide, titanium dioxide and zirconium dioxide, or a mixture of two or more thereof. delete The method according to claim 1,
Wherein the adhesion-promoting agent is 0.05 to 2% by weight based on the polyamide-imide resin layer containing the adhesion-promoting agent.

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