JPH0680911A - Insulation paint for electric wire and insulated electric wire formed using the same - Google Patents

Abstract

(57) [Summary] [Object] The present invention maintains the characteristics of an insulating coating by mixing a specific aromatic compound that imparts self-lubricating properties to a coating for electric wires with a coating-forming resin group. At the same time, it is an object of the present invention to provide an insulating coating material for electric wires, which is particularly excellent in self-lubricating property and wear resistance, and an insulated electric wire formed using the same. According to the present invention, there is provided an insulating coating material for electric wires, characterized in that an aromatic compound represented by the following general formula is mixed with a coating resin group capable of forming a film. [Chemical 1] (However, the total carbon number of R ₁ , R ₃ , R _4, and R ₅ is 20 or more, and the carbon number of any of these organic groups is 1
It is 0 or more. )

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating coating material for electric wires, which is capable of forming a film having excellent self-lubricating property, and an insulated electric wire formed using the same.

[0002]

2. Description of the Related Art In recent years, high-speed automatic winding machines have been used for coil winding work of motors, transformers, etc. However, since the insulation strength of ordinary insulated wires is weak, the coating is easily damaged by friction during high-speed operation.

As an insulated wire that can withstand this high-speed operation, a self-lubricated insulated wire having various types of wax or the like added to improve the lubricity is used. For example, liquid lubricant such as liquid paraffin or solid lubricant such as solid paraffin may be applied on the outermost insulating coating film, or insulating paint that contains resin powder with excellent lubricity such as polyethylene and polypropylene, Coating and baking on a conductor are mentioned.

[0004]

However, the conventional self-lubricating insulated wire has the following problems.

That is, the conventional self-lubricating insulated wire has an excellent surface friction coefficient, but depending on the application, wax or the like may be extracted by a solvent or the like to cause contamination around the coil.

Further, although the conventional self-lubricating insulated wire has an excellent surface friction coefficient, it has extremely poor wear resistance. In the case of multi-layer coating, the abrasion resistance of the lower insulating film layer may be impaired.

The present invention has been completed in view of the above technical problems, and by mixing a specific aromatic compound which imparts a self-lubricating property to a film for electric wires, to a film forming resin group capable of forming a film. It is an object of the present invention to provide an insulating coating material for electric wires, which is particularly excellent in self-lubricating property and abrasion resistance while maintaining the characteristics of the insulating coating material, and an insulated electric wire formed using the same.

[0008]

In order to achieve the above-mentioned object, the insulating coating material for electric wire of the present invention is characterized in that a compound represented by the following general formula is mixed with a coating-forming resin group for coating material. It is what

[0009]

[Chemical 21]

(However, the total carbon number of R ₁ , R ₃ , R ₄ and R ₅ is 20 or more, and the organic group of any of these is 10 or more.)

The present invention will be described in detail below. The coating-forming resin group capable of forming a film in the present invention is not particularly limited as long as it is a resin used for coating an electric wire, and specifically, for example, polyvinyl formal, polyurethane, polyester, polyester imide. , Those containing polyamide imide or polyimide as the film component.

Among the coating resin group, particularly, heat resistance,
Considering abrasion resistance and surface lubricity, a polyamide-imide resin coating is most suitable. Polyamideimide is generally obtained by heating and condensing an aromatic tricarboxylic acid anhydride and an aromatic isocyanate in a synthetic solvent.Polyamideimide varnish has excellent heat resistance and high mechanical strength. The varnish is also used as an overcoat varnish in a double coat, but the drawback is that the lubricity is poor and the workability is poor. Particularly preferably used.

The insulating coating material for electric wires of the present invention is most characterized in that it is formed by mixing the above-mentioned coating resin group capable of forming a film with an aromatic component imparting self-lubricating property, which will be described later. is there.

The aromatic component imparting self-lubricating property used in the present invention is not particularly limited as long as it contains an aromatic ring represented by the following general formula.

[0015]

[Chemical formula 22]

(However, the total carbon number of R ₁ , R ₃ , R ₄ and R ₅ is 20 or more, and the organic group of any of these is 10 or more.)

That is, in the present invention, in the above general formula, the total carbon number of R ₁ , R ₃ , R ₄ and R ₅ is 20 or more, and the carbon number of any of these organic groups is 10
Due to the above, excellent self-lubricating property is imparted to the coating resin group.

Of these, in particular, in the above general formula, R ₁ and R ₃ are monovalent organic groups or H, and R ₂ is a single bond or a divalent organic group. , R ₄ and R ₅ are monovalent organic groups, saturated or unsaturated alkyl groups having 10 to 40 carbon atoms or 10 carbon atoms.
A fluorine-containing alkyl group of 40 or a monovalent organic group having a repeating number of CH ₂ and / or CF ₂ of 10 to 40 imparts more excellent self-lubricating properties to the coating resin group. Be beneficial.

In the present invention, in the following general formula,

[0020]

[Chemical formula 23]

R ₁ and R ₃ are --NH ₂ , RNHCONH--
(R is a saturated or an alkyl group or a fluorine-containing unsaturated alkyl group), a reactive group or -NO _2, such as isocyanate groups, blocked isocyanate groups, 2 wherein R ₂ is selected from a single bond or the following structural formula A valent organic group, R ₄
And R ₅ is a monovalent organic group selected from an alkyl ester group or a fluorine-containing alkyl ester group, or a monovalent organic group having a cyclic structure, has an extremely excellent self-lubricating property for a coating resin group. It is useful because it can be given.

[0022]

[Chemical formula 24]

[0023]

[Chemical 25]

[0024]

[Chemical formula 26]

[0025]

[Chemical 27]

[0026]

[Chemical 28]

[0027]

[Chemical 29]

[0028]

[Chemical 30]

[0029]

[Chemical 31]

[0030]

[Chemical 32]

[0031]

[Chemical 33]

[0032]

[Chemical 34]

[0033]

[Chemical 35]

[0034]

[Chemical 36]

[0035]

[Chemical 37]

[0036]

[Chemical 38]

[0037]

[Chemical Formula 39]

Or

[0039]

[Chemical 40]

In the present invention, in the above general formula,
The total carbon number of R ₁ , R ₃ , R ₄ and R ₅ is 20 or more,
Moreover, it is necessary that any one of these organic groups has 10 or more carbon atoms, but when the organic group is eliminated during coating or baking like a reactive group such as a blocked isocyanate group. Does not add the carbon number of this organic group.

In the present invention, in the following general formula,

[0042]

[Chemical 41]

R ₁ and R ₃ are monovalent organic groups or H,
R ₂ is a single bond or a divalent organic group, and further R ₄
It is advantageous that R ₅ and R ₅ are monovalent organic groups having a saturated or unsaturated cyclic structure having 10 to 40 carbon atoms because they can impart extremely excellent self-lubricating property to the coating resin group.

R ₄ and R ₅ are not particularly limited as long as they are monovalent organic groups having a saturated or unsaturated cyclic structure having 10 to 40 carbon atoms.

As a concrete representative example of this, for example,

[0046]

[Chemical 42]

Or

[0048]

[Chemical 43]

And the like.

In the insulating coating for electric wires of the present invention, the following general formula is used.

[0051]

[Chemical 44]

In, R ₂ is

[0053]

[Chemical formula 45]

Or

[0055]

[Chemical formula 46]

The following is advantageous because it exhibits excellent self-lubricating property.

In the present invention, when the above-mentioned aromatic compound is mixed with a coating-forming resin group capable of forming a film and applied to an electric wire and baked to form a film, when forming a domain, that is, a sea-island structure, By forming the island portion, the frictional resistance is remarkably reduced, and thus the abrasion resistance is remarkably improved.

In the present invention, the mixing ratio of the coating resin group (A) and the specific aromatic component (B) varies depending on the combination of (A) and (B), but in general,
0.5 to 2 of (B) with respect to 100 parts by weight of the solid content of (A).
It is desirable that the amount is 0, particularly 1 to 10 parts by weight.

If the blending ratio of (B) is less than 0.5, the required lubricity and wear resistance may not be obtained, while if it exceeds 20, the properties of the coating resin are adversely affected. In some cases, adverse effects such as an increase in cost may occur. Therefore, from these viewpoints, about 1 to 10 parts by weight is desirable.

In the present invention, the self-lubricating property is further improved by using the specific aromatic component (B) for imparting self-lubricating property together with the conventional self-lubricating component (C). It is also possible to do so.

In the present invention, the blending ratio of the specific aromatic component (B) and the conventional self-lubricating component (C) varies depending on the combination of (B) and (C), but generally (B). (C) is 10 per 100 parts by weight of solid content of
It is desirable that the amount be in the range of 300 to 300, especially 50 to 150 parts by weight.

When the compounding ratio of the above (C) is less than 10, it is meaningless to compound the compounded amount too much, while 30
If it exceeds 0, on the contrary, there are cases in which the properties of the coating resin are impaired and the intended purpose cannot be achieved, resulting in adverse effects. Therefore, from these viewpoints, 50 to 150
About parts by weight is desirable.

It is not necessary to use a special technique or apparatus for mixing the coating resin group (A) with the components (B) and (C), and it can be carried out by a conventional method. Specifically, for example, the aromatic component (B), and in some cases,
After dissolving this component (B) and the conventional self-lubricating component (C) in a solvent, the mixture is stirred and mixed with the coating resin group, or directly in the coating composition such as the aromatic component (B). May be added and sufficiently mixed with stirring to dissolve, or sufficiently mixed with stirring to disperse uniformly.

In order to achieve the above-mentioned object, the insulated wire of the present invention is characterized in that the above-mentioned insulating coating material for the wire is applied to a conductor directly or through another insulating layer and baked. Is.

As the other insulating layer used here, a usual varnish film, for example, a polyester film, a polyesterimide film, a polyamideimide film, a polyurethane film and the like can be mentioned.

[0066]

The insulating coating material for electric wire of the present invention has the above-mentioned constitution,
By mixing a specific aromatic compound that imparts self-lubricating properties to the paint-forming resin group that can form a film, the paint containing this aromatic component is applied to the wire and baked, It has the effect of improving the self-lubricating property while maintaining the characteristics of the film of the resin group.

Further, in this case, when the domain of the aromatic component is formed in the coating resin, the self-lubricating property and the abrasion resistance are both improved by the formation of the domain, and the surface is also improved. The presence of the micro domain has the effect of expressing the surface self-lubricating property.

Therefore, using this insulating paint,
Even if a coil such as a transformer is wound at high speed, it will not be damaged by friction, and the insulated wire thus obtained has a uniform and stable insulating film, so it has excellent electrical characteristics. It has an action to have.

[0069]

EXAMPLES The present invention will now be described in detail based on examples, but the present invention is not limited thereto.

Example 1 4-Chloro-5-nitro-benzoic acid (40.3 g), octadecyl alcohol (54.1 g) and 4,4-dimethylaminopyridine (2.7 g) were dissolved in ethyl acetate (410 ml). Carbodiimide was added. Two
After about 3 hours, insoluble matter was deposited and the reaction solution could not be stirred. However, after leaving it as it was overnight, ethyl acetate was removed under reduced pressure. Chloroform 1 in this reaction system
000 ml was added to remove insoluble matter, and the filtrate was directly concentrated under reduced pressure. The obtained residue was purified using a chromatographic column to obtain an ester form.

On the other hand, 20.4 g of bisphenol A was dissolved in 180 ml of dimethyl sulfoxide, 20 g of potassium t-butoxide was added, and the mixture was stirred for 2 hours. This solution was added dropwise to a solution of 80.9 g of the ester compound synthesized above in dimethyl sulfoxide at 80 to 90 ° C. After reacting for 2 hours, the reaction solution was added to 5000 ml of cold water, and the desired product was extracted with about 3000 ml of chloroform. The obtained chloroform layer was washed with diluted hydrochloric acid and water, dried over anhydrous magnesium sulfate, the desiccant was removed, and then the solvent was removed under reduced pressure. The obtained concentrated residue was recrystallized from ethyl acetate / ethanol (10/1) to obtain a dinitro compound having the following structural formula.

[0072]

[Chemical 47]

The obtained dinitro body was coated with 30% by weight of polyamideimide (resin for paint) (manufactured by Nitto Denko Corp., DAI).
-500) was added and mixed in an amount of 3 parts by weight with respect to 100 parts by weight of the resin content to obtain an insulating coating material for electric wire of the present invention.

Example 2 An insulated wire (having a diameter of 0.95 mm) having a thickness of 30 μm and a polyamide-imide insulating film (thickness 30 μm) provided in advance according to a conventional method using the insulating coating material for electric wire obtained in Example 1 The coated wire was applied and baked on the outside of the copper wire to form a coating layer having a thickness of 4 μm to obtain an insulated wire of the present invention.

Example 3 4-Chloro-5-nitro-benzoic acid (40.3 g), octadecyl alcohol (54.1 g) and 4,4-dimethylaminopyridine (2.7 g) were dissolved in ethyl acetate (410 ml). Carbodiimide was added. Two
After about 3 hours, insoluble matter was deposited and the reaction solution could not be stirred. However, after leaving it as it was overnight, ethyl acetate was removed under reduced pressure. Chloroform 1 in this reaction system
000 ml was added to remove insoluble matter, and the filtrate was directly concentrated under reduced pressure. The obtained residue was purified using a chromatographic column to obtain an ester form.

On the other hand, 20.4 g of bisphenol A was dissolved in 180 ml of dimethyl sulfoxide, 20 g of potassium t-butoxide was added, and the mixture was stirred for 2 hours. This solution was added dropwise to a solution of 80.9 g of the ester compound synthesized above in dimethyl sulfoxide at 80 to 90 ° C. After reacting for 2 hours, the reaction solution was added to 5000 ml of cold water, and the desired product was extracted with about 3000 ml of chloroform. The obtained chloroform layer was washed with diluted hydrochloric acid and water, dried over anhydrous magnesium sulfate, the desiccant was removed, and then the solvent was removed under reduced pressure. The concentrated residue obtained was recrystallized from ethyl acetate / ethanol (10/1). Suspend this dinitro form in ethyl acetate,
After adding 1 g of platinum oxide, hydrogen gas was introduced at room temperature.
After confirming that the reaction was completed after 10 hours, the catalyst was removed, the solvent was further removed under reduced pressure, and the residue was crystallized. The structural formula of the crystal thus obtained is

[0077]

[Chemical 48]

It was

The diamine obtained here was used as a coating material for polyamide imide (resin for paint) 30% by weight (manufactured by Nitto Denko Corporation, D
3 parts by weight of AI-500) was added and mixed with 100 parts by weight of the resin content to obtain an insulating coating material for electric wire of the present invention.

Example 4 The insulating coating material for electric wire obtained in Example 3 was used, and the insulating coating material for electric wire was applied to the insulated electric wire (diameter: 0 μm) having a thickness of 30 μm of polyamide-imide insulating coating (thickness: 30 μm). .9
5 mm copper wire) is coated by a conventional method on the outside of the furnace temperature 410 ° C., middle part 370 ° C., lower part 210 ° C., linear speed 5.5.
Baking was performed under the condition of m / min to form a coating layer having a thickness of 4 μm to obtain an insulated wire of the present invention.

Example 5 6 parts by weight of the diamine obtained in Example 3 was added to 30% by weight of polyamide-imide (resin for coating material) coating material and mixed with 6 parts by weight of the resin component, and the insulating coating material for electric wire of the present invention was obtained. Got

Example 6 The insulating coating material for electric wires obtained in Example 5 was used, and the insulating coating material for electric wires was previously coated with a polyamide-imide insulating coating having a thickness of 30 μm (copper wire having a diameter of 0.95 mm). ) Was coated and baked on the outside in the same manner as in Example 4 to form a coating layer having a thickness of 4 μm to obtain an insulated wire of the present invention.

Example 7 In Example 3, instead of octadecyl alcohol,
Synthesis was performed in the same manner as in Example 1 except that 1-docosanol was used to obtain a diamine having the following structural formula.

[0084]

[Chemical 49]

The resulting diamine was added to and mixed with 30% by weight of polyamide-imide (resin for coating material) coating material in an amount of 3 parts by weight based on 100 parts by weight of the resin content to obtain an insulating coating material for electric wires of the present invention.

Example 8 Using the insulating coating material for electric wire obtained in Example 7, the insulating coating material for electric wire was previously provided with a polyamide-imide insulating coating having a thickness of 30 μm (copper wire having a diameter of 0.95 mm). ) Was coated and baked on the outside in the same manner as in Example 4 to form a coating layer having a thickness of 4 μm to obtain an insulated wire of the present invention.

Example 9 The diamine obtained in Example 3 and a long-chain alkyl isocyanate (octadecyl isocyanate) were reacted in toluene at a molar ratio of 1: 1 to have a urea bond and having the following structural formula 4. An alkyl chain was obtained.

[0088]

[Chemical 50]

The obtained 4-alkyl chain was added to and mixed with 30% by weight of polyamide-imide coating material in an amount of 3 parts by weight based on 100 parts by weight of the resin content, to obtain an insulating coating material for electric wire of the present invention.

Example 10 The insulating coating material for electric wires obtained in Example 9 was used, and the insulating coating material for electric wires was previously provided with a polyamide-imide insulating coating having a thickness of 30 μm (copper wire having a diameter of 0.95 mm). ) Was coated and baked on the outside in the same manner as in Example 4 to form a coating layer having a thickness of 4 μm to obtain an insulated wire of the present invention.

Example 11 In Example 3, instead of octadecyl alcohol,
Synthesis was performed in the same manner as in Example 1 except that cholesterol was used to obtain a diamine having the following structural formula.

[0092]

[Chemical 51]

However, R ₇ is

[0094]

[Chemical 52]

It is

The resulting diamine was added to and mixed with 30% by weight of polyamideimide (resin for paint), 3 parts by weight based on 100 parts by weight of the resin content, to obtain an insulating coating for electric wires of the present invention.

Example 12 Using the insulating coating material for electric wire obtained in Example 11, the insulating coating material for electric wire was previously provided with a polyamide-imide insulating coating having a thickness of 30 μm (copper wire having a diameter of 0.95 mm). ) Was coated and baked on the outside in the same manner as in Example 4 to form a coating layer having a thickness of 4 μm to obtain an insulated wire of the present invention.

Comparative Example 1 The comparative insulated wire formed with the polyamide-imide insulating film used in Example 2 was used. In this case, the film thickness was 34 μm in order to make the total film thickness uniform.

Comparative Example 2 Polyamide-imide-coated polyamide-imide coating was applied and baked on the polyamide-imide film-formed insulated wire (film thickness 30 μm) used in Example 2 by a conventional method to give a comparative insulated wire. .

Comparative Example 3 4-Chloro-5-nitro-benzoic acid (40.3 g), octadecyl alcohol (54.1 g) and 4,4-dimethylaminopyridine (2.7 g) were dissolved in ethyl acetate (410 ml), and dicyclohexyl was added thereto while cooling with ice. Carbodiimide was added. Two
After about 3 hours, insoluble matter was deposited and the reaction solution could not be stirred. However, after leaving it as it was overnight, ethyl acetate was removed under reduced pressure. Chloroform 1 in this reaction system
000 ml was added to remove insoluble matter, and the filtrate was directly concentrated under reduced pressure. The obtained residue was purified using a chromatographic column to obtain an ester form. 10 g of this ester compound was suspended in ethyl acetate, 0.15 g of platinum oxide was added, and then hydrogen gas was introduced at room temperature. After 10 hours, it was confirmed that the reaction was completed, and the catalyst was removed. After removing the solvent under reduced pressure, the residue was crystallized. The structural formula of the obtained crystal is shown below.

[0101]

[Chemical 53]

The obtained mono-long-chain-containing alkylamine was added to a coating of 30% by weight of polyamideimide in an amount of 3 parts by weight with respect to 100 parts by weight of the resin content to obtain an insulating coating.

This insulating coating was applied and baked on the outside of an insulated wire provided with a polyamideimide insulating coating having a thickness of 30 μm by a conventional method to form a coating layer having a thickness of 4 μm to obtain a comparative insulated wire.

Table 1 shows the results of measurement of lubricity (static friction coefficient) and wear resistance (number of reciprocating frictions) using the insulated wire of each example and the insulated wire of each comparative example.

[0105]

[Table 1]

In Table 1, the coefficient of static friction was measured by the coefficient of friction between lines. That is, two sample electric wires are attached in parallel to a metal block (200 g), and four parallel sample electric wires are placed on the flat plate so that each of them makes a right angle. Is raised at a constant speed,
It is obtained from the angle when the metal block starts to move.

In Table 1, the abrasion resistance is JIS-C3.
It was measured by a 003 reciprocating abrasion tester (load 600 g).

Table 2 shows the results of measuring the solvent resistance of the insulated wire of each example and the insulated wire of each comparative example.

[0109]

[Table 2]

In Table 2, as a solvent resistance evaluation, the coefficient of static friction after dipping and wiping with ethanol for 40 minutes was measured in the same manner as in the above case. The same procedure was performed using chloroform instead of ethanol.

From the results shown in Tables 1 and 2, it is recognized that each of the examples is significantly superior in self-lubricating property, abrasion resistance and solvent resistance to each of the comparative examples.

[0112]

EFFECTS OF THE INVENTION The insulating coating material for electric wire of the present invention has the above-mentioned constitution, and by mixing a specific aromatic compound which imparts self-lubricating property to the coating film-forming resin group,
When the paint mixed with this aromatic component is applied to an electric wire and baked, the self-lubrication property is improved while maintaining the film characteristics of the paint resin group. Even so, the film is not damaged, and the electrical characteristics are stabilized.

Further, in this case, when the domain of the aromatic component is formed in the coating resin, the self-lubricating property and the wear resistance are both improved by the formation of the domain, and the surface is also improved. Since the self-lubricating property of the surface is exhibited due to the presence of the microdomains, a more excellent resin film can be obtained.

By the way, in the electric wire insulating coating composition of the present invention, a specific aromatic compound which imparts self-lubricating property to the film is used, and since this composition has a relatively high molecular weight and good solvent resistance, As a result, wax or the like is not extracted, and as a result, it is possible to prevent contamination of the coil peripheral portion.

Therefore, using this insulating paint,
Since the damage due to friction does not occur even when the coil winding of a transformer or the like is performed at high speed, productivity is significantly improved and it is extremely economical, and the insulated wire thus obtained has a uniform insulating film and Since it is stable, it has excellent electrical characteristics and is extremely useful.

Claims (7)

[Claims] 1. An insulating coating material for electric wires, comprising an aromatic compound represented by the following general formula mixed with a coating-forming resin group capable of forming a film. [Chemical 1] (However, the total carbon number of R ₁ , R ₃ , R _4, and R ₅ is 20 or more, and the carbon number of any of these organic groups is 1
It is 0 or more. ) 2. R ₁ and R ₃ are monovalent organic groups or H, R ₂ is a single bond or a divalent organic group, and R ₄ and R ₅ are monovalent organic groups, Alternatively, a saturated or unsaturated alkyl group having 10 to 40 carbon atoms or 10 carbon atoms
The insulating paint for electric wires according to claim 1, wherein the fluorine-containing alkyl group is 40 or a monovalent organic group having a repeating number of CH ₂ and / or CF ₂ of 10 to 40. 3. R ₁ and R ₃ are —NH ₂ , RNHCONH—
(R is a saturated or an alkyl group or a fluorine-containing unsaturated alkyl group), a reactive group or -NO _2, such as isocyanate groups, blocked isocyanate groups, 2 wherein R ₂ is selected from a single bond or the following structural formula A valent organic group, R ₄
And R ₅ is a monovalent organic group selected from an alkyl ester group or a fluorine-containing alkyl ester group, or a monovalent organic group having a cyclic structure. [Chemical 2] [Chemical 3] [Chemical 4] [Chemical 5] [Chemical 6] [Chemical 7] [Chemical 8] [Chemical 9] [Chemical 10] [Chemical 11] [Chemical 12] [Chemical 13] [Chemical 14] [Chemical 15] [Chemical 16] [Chemical 17] Or 4. R ₁ and R ₃ are monovalent organic groups or H, R ₂ is a single bond or a divalent organic group, and R ₄ and R ₅ are saturated or unsaturated carbons. Number 10-4
The insulating coating material for electric wire according to any one of claims 1 to 3, which is a monovalent organic group having a ring structure of 0. 5. The insulating coating material for electric wires according to claim 1, wherein the coating resin group is polyamideimide. 6. The insulating coating material for electric wire according to claim 1, wherein R ₂ in the general formula is Or Insulation paint for electric wires. 7. An insulated electric wire, characterized in that the insulating coating material for electric wire according to any one of claims 1 to 6 is applied and baked on a conductor directly or through another insulating layer.