JPH0721849A - Insulated wire - Google Patents

Abstract

PURPOSE:To provide an insulated wire excellent in flexibility and high temperature heat resisting softening property by applying a polyamide imide coating material containing specified amounts of polyisocyanate component and polycarboxylic acid compound followed by baking to form an insulating coat. CONSTITUTION:A polyamide coating material having isocyanate component containing at least a diisocyanate compound and acid component as starting materials is applied to a wire followed by baking to form an insulating coat, whereby an insulated wire is provided. The isocyanate component as the starting material contains a multifunctional polyisocyanate compound having three or more isocyanate groups, and the acid component contains at least one multifunctional polycarboxylic acid compound having three or more carboxylic groups. The total content ratio of the polyisocyanate compound and the polycarboxylic acid to the sum of the isocyanate component and the acid component is set to 0.5-8mol%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated wire which is wound around a core of a motor and has excellent workability.

[0002]

2. Description of the Related Art In recent years, with the trend toward smaller size and lighter weight of equipment, there has been a demand for smaller and lighter motors with higher performance. To meet this requirement, it is necessary to wind more insulated wires around the motor core, but this will forcefully pack the insulated wires into the slots of the core, and there is a risk that the insulating coating will be damaged during the winding process. is there. When the insulating coating is damaged, there is a problem that a lare defect, a ground defect, etc. occur, causing a problem in the electric characteristics of the motor.

Therefore, an insulated wire having an insulating coating excellent in mechanical strength, which is formed by coating and baking a polyamideimide-based paint, is usually used for the above-mentioned use. As the polyamide-imide, a reaction product of diphenylmethane-4,4'-diisocyanate and trimellitic anhydride is generally used (for example, JP-B-44-19274 and JP-B-45-276).
No. 11, etc.).

[0004]

However, in recent years, motors with smaller size, lighter weight and better performance are required, and in order to meet the demand, the winding amount of the insulated wire tends to further increase, and the insulation in the slot of the core is increased. The wires are stuffed forcibly. For this reason, the insulated wire in the slot comes into contact with each other under a high load, and is more likely to generate heat. Therefore, in a typical polyamide-imide insulating coating, the insulating coating is heated by heat during use. There is a problem that there is a high risk of softening and a rare short circuit in which the conductors come into contact with each other.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an insulated wire having an insulating coating film which is excellent in flexibility and heat softening resistance at high temperature. There is.

[0006]

In order to solve the above problems, the present inventors have studied the structure of polyamide-imide. As a result, when a polyfunctional group having three or more functional groups is used to introduce a polyfunctional group into the structure of the polyamide-imide and the crosslink density thereof is improved, the heat softening resistance is improved and It has been found that an insulating film that is less likely to cause a short-circuit can be formed even underneath. Then, as a result of further studying what proportion of the crosslinked structure should be introduced into the structure, the present invention has been completed.

That is, the insulated wire of the present invention is an insulated wire having an insulating coating formed by applying and baking a polyamideimide-based coating material containing an isocyanate component containing at least a diisocyanate compound and an acid component as raw materials. Component and acid component,
Polyfunctional polyisocyanate compound having three or more isocyanate groups and at least one polyfunctional polycarboxylic acid compound having three or more carboxylic acid groups, and the total amount of isocyanate component and acid component To the total content of these polyisocyanate compounds and polycarboxylic acid compounds is 0.5 to 8 mol%
Is characterized in that.

Further, another insulated wire of the present invention is a polyamide-imide prepared from an imido dicarboxylic acid which is a reaction product of an amine component containing at least a diamine compound and an acid component, and an isocyanate component containing at least a diisocyanate compound. In an insulated wire having an insulating coating formed by applying and baking a system-based paint, an amine component, an acid component, and an isocyanate component as raw materials are polyfunctional polyamine compounds having three or more amino groups, and three or more carboxyls. A polyfunctional polycarboxylic acid compound having an acid group and at least one of a polyfunctional polyisocyanate compound having three or more isocyanate groups are contained, and these are contained in the total amount of the amine component, the acid component and the isocyanate component. Polyamine compound, polycarboxylic acid compound, polyamine The total content of the cyanate compound, characterized in that 0.5 to 8 mol%.

In the former case of the present invention, in the case of producing a polyamideimide by a one-step reaction from an isocyanate component and an acid component, the polyfunctional polyisocyanate compound contained in the isocyanate component as a raw material is
Polyisocyanate, which is a trimer of triphenylmethane triisocyanate, diphenyl ether triisocyanate, and diisocyanate compound (Desmodur L and Desmodur AP, trade names of Sumitomo Bayer Urethane Co., Ltd.
Etc.), polymethylene polyphenyl isocyanate and the like. These can be used alone or in combination of two or more.

The polyfunctional polycarboxylic acid compound contained in the acid component as a raw material is trimellitic acid,
Pyromellitic acid, butanetetracarboxylic acid, biphenyltetracarboxylic acid, benzophenonetetracarboxylic acid,
Examples include diphenyl sulfone tetracarboxylic acid. These can be used alone or in combination of two or more.

Of these polycarboxylic acid compounds, the following formula (3):

[0012]

[Chemical 3]

The trimellitic acid represented by the following formula is preferably used in the present invention. In the present invention, the isocyanate component and the acid component as raw materials contain at least one of the polyisocyanate compound and the polycarboxylic acid compound, and with respect to the total amount of the isocyanate component and the acid component, the polyisocyanate compound and / Alternatively, the total content of the polycarboxylic acid compounds is 0.
It is limited to 5 to 8 mol%.

More specifically, in the present invention, an isocyanate component as a raw material contains a polyisocyanate compound, an acid component as a raw material contains a polycarboxylic acid compound, and an isocyanate component as a raw material contains a polyisocyanate compound In addition, there are three cases of containing a polycarboxylic acid compound in the acid component. In the case of, the content ratio of the polyisocyanate compound to the total amount of the isocyanate component and the acid component is limited to 0.5 to 8 mol%. In the case of, the content ratio of the polycarboxylic acid compound with respect to the total amount of the isocyanate component and the acid component is limited to 0.5 to 8 mol%, and in the case of, with respect to the total amount of the isocyanate component and the acid component, the polyisocyanate compound, the polyisocyanate compound The total content of carboxylic acid compounds is 0.5 to It is limited to mol%.

If the above content ratio is less than 0.5 mol%,
Since a sufficient crosslinked structure cannot be obtained and the crosslink density is low, the insulating coating tends to be softened by heat. On the other hand, when the content ratio exceeds 8 mol%, the cross-linking density is too high, so that the insulating coating is rigid and inferior in flexibility, and easily cracks or peels off. The above content ratio is preferably within the range of 0.5 to 3 mol% in the above range.

As the other isocyanate contained in the isocyanate component together with the polyisocyanate compound, at least a diisocyanate compound is an essential component for obtaining polyamideimide. As the diisocyanate compound, an aromatic diisocyanate having an aromatic ring in its structure is preferably used. Examples of aromatic diisocyanates include diphenylmethane-
4,4'-diisocyanate, diphenylmethane-3,
3'-diisocyanate, diphenylmethane-3,4 '
-Diisocyanate, diphenyl ether-4,4'-
Diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, naphthylene-1,5
-Diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate and the like may be mentioned various conventionally known compounds. These may be used alone or in combination of two or more.

Further, the following general formula (1):

[0018]

[Chemical 4]

[Wherein R ¹ and R ² are the same or different,
A hydrogen atom, an alkyl group, an alkoxy group or a halogen atom is shown. m and n are the same or different and represent a number of 1 to 4. ] A system containing an aromatic diisocyanate compound represented by the following in the isocyanate component in a proportion of 10 to 80 mol% is suitable from the viewpoint of increasing the strength of the insulating coating, but on the other hand, it causes a large decrease in heat softening resistance. The configuration of the present invention is actively adopted. Incidentally, the aromatic isocyanate compound,
In a system containing more than 80 mol% in the isocyanate component, the heat softening resistance is remarkably reduced, and therefore, even if a polyfunctional component is blended, a sufficient effect cannot be obtained.

Specific examples of the aromatic diisocyanate compound represented by the general formula (1) include biphenyl-4,4'-diisocyanate and biphenyl-3,3 '.
-Diisocyanate, biphenyl-3,4'-diisocyanate, 3,3'-dichlorobiphenyl-4,4'-
Diisocyanate, 2,2'-dichlorobiphenyl-
4,4'-diisocyanate, 3,3'-dibromobiphenyl-4,4'-diisocyanate, 2,2'-dibromobiphenyl-4,4'-diisocyanate, 3,
3'-dimethylbiphenyl-4,4'-diisocyanate, 2,2'-dimethylbiphenyl-4,4'-diisocyanate, 2,3'-dimethylbiphenyl-4,4 '
-Diisocyanate, 3,3'-diethylbiphenyl-
4,4'-diisocyanate, 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 2,
2'-dimethoxybiphenyl-4,4'-diisocyanate, 2,3'-dimethoxybiphenyl-4,4'-diisocyanate, 3,3'-diethoxybiphenyl-
4,4'-diisocyanate, 2,2'-diethoxybiphenyl-4,4'-diisocyanate, 2,3'-diethoxybiphenyl-4,4'-diisocyanate and the like can be mentioned. These may be used alone or in combination of two or more.

Among the above-mentioned aromatic diisocyanate compounds, 3,3'-dimethylbiphenyl-4,4'-diisocyanate represented by the following formula (1a) is preferable in view of availability and cost. used.

[0022]

[Chemical 5]

Other acid components contained in the acid component together with the polycarboxylic acid compound include trimellitic anhydride,
Examples thereof include trimellitic acid chloride, and tribasic acid among trimellitic acid derivatives. In particular, trimellitic anhydride represented by the following formula (4) is preferably used in terms of availability and cost.

[0024]

[Chemical 6]

In the acid component, tetracarboxylic acid anhydride or dibasic acid such as pyromellitic acid dianhydride, biphenyltetracarboxylic acid dianhydride, benzophenonetetracarboxylic acid dianhydride, diphenylsulfonetetracarboxylic acid is used. Dianhydride, terephthalic acid, isophthalic acid, sulfoterephthalic acid, dicitric acid, 2,5-thiophenedicarboxylic acid, 4,5-phenanthrenedicarboxylic acid, benzophenone-4,4'-dicarboxylic acid, phthaldiimidedicarboxylic acid, biphenyldicarboxylic acid Acid, 2,6-naphthalenedicarboxylic acid, diphenyl sulfone-4,4'-
A part of dicarboxylic acid, adipic acid, etc. may be added.

From the above isocyanate component and acid component,
In order to produce the polyamide-imide-based coating used in the present invention, for example, a substantially stoichiometric amount of an isocyanate component and an acid component are copolymerized in a suitable organic solvent. A manufacturing method can be adopted. More specifically, the isocyanate component and the acid component, which contain the polyisocyanate compound and / or the polycarboxylic acid compound in the above-described proportions and are approximately equimolar, are mixed in a suitable organic solvent at a temperature of 0 to 180 ° C. 24
When the reaction is allowed to proceed for a period of time, a polyamide-imide-based paint in which polyamide-imide, which is a copolymer of an isocyanate component and an acid component, is dissolved or dispersed in an organic solvent is obtained.

In the latter case of the present invention, in the case of a two-step reaction in which an amine component and an acid component are reacted to obtain imidedicarboxylic acid and the imidedicarboxylic acid is reacted with an isocyanate component to produce polyamideimide. Examples of the polyfunctional polyamine compound contained in the amine component as a raw material include diphenylmethanetetraamine, phenylenetriamine, diethylenetriamine and triethylenetetraamine. These can be used alone or in combination of two or more.

Of these polyamine compounds, the following formula (5):

[0029]

[Chemical 7]

3,4,3 ', 4'-biphenyltetramine represented by the formula: is preferably used in the present invention. Examples of the polycarboxylic acid compound and the polyisocyanate compound include the various compounds exemplified above. In the present invention, the amine component, the acid component and the isocyanate component as raw materials contain at least one of the polyamine compound, the polycarboxylic acid compound and the polyisocyanate compound, and the amine component, the acid component and the isocyanate component These polyamine compounds relative to the total amount,
The total content of the polycarboxylic acid compound and the polyisocyanate compound is limited to 0.5 to 8 mol%.

More specifically, in the present invention, the amine component as a raw material contains a polyamine compound, the acid component as a raw material contains a polycarboxylic acid compound, and the isocyanate component as a raw material contains a polyisocyanate compound. , Containing a polyamine compound in the amine component as a raw material and a polycarboxylic acid compound in the acid component, including a polyamine compound in the amine component as a raw material, and a polyisocyanate compound in the isocyanate component as a raw material In addition to containing the polycarboxylic acid compound in the acid component of, the polyisocyanate compound in the isocyanate component, the polyamine compound in the amine component as a raw material, the polycarboxylic acid compound in the acid component There are seven cases of containing a polyisocyanate compound in the isocyanate component. In the case of, the content ratio of the polyamine compound to the total amount of the amine component, the acid component and the isocyanate component is limited to 0.5 to 8 mol%, In the case of, the content ratio of the polycarboxylic acid compound with respect to the total amount of the above three components is limited to 0.5 to 8 mol%, and in the case of, the content ratio of the polyisocyanate compound with respect to the total amount of the above three components is 0.5 to Limited to 8 mol%.

In the other case, the total content of the polyamine compound and the polycarboxylic acid compound is limited to 0.5 to 8 mol% with respect to the total amount of the above three components.
The content ratio of the total of the polyamine compound and the polyisocyanate compound is limited to 0.5 to 8 mol% with respect to the total amount of the three components. In the case of, the content of the polycarboxylic acid compound and the polyisocyanate compound relative to the total amount of the three components is The total content is limited to 0.5 to 8 mol%.

In the above case, the total content of the polyamine compound, the polycarboxylic acid compound and the polyisocyanate compound is 0.5 with respect to the total amount of the above three components.
Limited to ~ 8 mol%. If the content ratio is less than 0.5 mol%, a sufficient crosslinked structure cannot be obtained and the crosslink density is low, so that the insulating coating tends to be softened by heat. On the other hand, when the content ratio exceeds 8 mol%, the cross-linking density is too high, so the insulating coating is rigid and inferior in flexibility,
It becomes easy to crack and peel.

The above content ratio is preferably within the range of 0.5 to 3 mol%, among the above range.
As the other amine contained in the amine component together with the polyamine compound, at least a diamine compound is an essential component for obtaining polyamideimide. As the diamine compound, an aromatic diamine having an aromatic ring in its structure is preferably used.

As the aromatic diamine, for example, 4,
4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,
4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodibenzophenone, 4,4'-diaminodiphenylpropane,
4,4'-diaminodiphenylhexafluoropropane, 4,4 '-[bis (4-aminophenoxy)] biphenyl, 4,4'-[bis (4-aminophenoxy)]
Diphenyl ether, 4,4 '-[bis (4-aminophenoxy)] diphenyl sulfone, 4,4'-[bis (4-aminophenoxy)] diphenylmethane, 4,
4 '-[bis (4-aminophenoxy)] diphenylpropane, 4,4'-[bis (4-aminophenoxy)]
Examples include various conventionally known diamine compounds such as diphenylhexafluoropropane. These may be used alone or in combination of two or more.

In particular, the following general formula (2):

[0037]

[Chemical 8]

[Wherein R ³ and R ⁴ are the same or different,
A hydrogen atom, an alkyl group, an alkoxy group or a halogen atom is shown. p and q are the same or different and represent a number of 1 to 4. ] A system containing an aromatic diamine compound represented by and / or an aromatic diisocyanate compound represented by the general formula (1) at a ratio of 10 to 80 mol% in the total amount of the amine component and the isocyanate component is Although it is preferable in terms of increasing the strength of the insulating coating, it has a large decrease in heat softening resistance, so that the constitution of the present invention is positively adopted. In the system containing the aromatic diamine compound and the aromatic isocyanate compound in a total amount of more than 80 mol% in the total amount of the amine component and the isocyanate component, the heat softening resistance is remarkably lowered, so that a polyfunctional component should be added. But not enough effect.

Specific examples of the aromatic diamine compound represented by the above general formula (2) include, for example, benzidine, 3-methyl-4,4'-diaminobiphenyl and 3,3'-dimethyl-4,4'-. Diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-3,4'-diaminobiphenyl, 3, 3'-dimethyl-3,3'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-diethoxy- 4,4'-diaminobiphenyl, 3,3'-
Dichloro-4,4'-diaminobiphenyl, 3,3'-
Examples include dibromo-4,4'-diaminobiphenyl and the like. These may be used alone or in combination of two or more.

Among the above aromatic diamine compounds, 3,3'-dimethyl-4,4'-diaminobiphenyl represented by the following formula (2a) is the present invention in view of availability and cost. Most preferably used.

[0041]

[Chemical 9]

As the acid component, the isocyanate component, the polycarboxylic acid compound contained in the acid component, and the polyisocyanate compound contained in the isocyanate component, the ones exemplified in the above invention are used. it can. In order to produce the polyamideimide-based coating used in the present invention from the amine component, the acid component and the isocyanate component, for example, a substantially stoichiometric amount of the amine component and the acid component are reacted in a suitable organic solvent. It is possible to employ the same production method as that for a conventional polyamide-imide-based coating composition in which imide dicarboxylic acid is produced and is copolymerized with a substantially stoichiometric amount of an isocyanate component.

More specifically, the acid component and its approximately 1/2
A molar amount of amine component of 0 to 15 in a suitable organic solvent.
When the reaction is carried out at a temperature of 0 ° C. for 1 to 24 hours, imidodicarboxylic acid which is a reaction product of an amine component and an acid component is produced in the reaction solution. Next, to this reaction solution, an isocyanate component in an approximately equimolar amount with imidodicarboxylic acid was added,
By reacting at a temperature of 0 to 150 ° C. for 1 to 24 hours, a polyamideimide-based coating material in which polyamideimide is dissolved or dispersed in an organic solvent is obtained.

If necessary, various additives such as pigments, dyes, inorganic or organic fillers and lubricants may be added to the polyamide-imide type coating material used in the present invention. The insulated wire of the present invention is manufactured by applying the above-mentioned polyamide-imide-based coating material directly to the surface of the wire or through an underlying layer made of another insulating material and baking it to form an insulating coating.

The film thickness of the insulating coating is not particularly limited in the present invention, and it can be formed to the same film thickness as the conventional one, depending on the size of the electric wire and the like. When the above-mentioned polyamide-imide-based coating material is applied and baked on a base layer made of another insulating material, the base layer is preferably made of a material having good adhesion to the insulating coating and the electric wire.

The base layer is an insulating film formed by coating and baking various conventionally known insulating coating materials such as polyurethane, polyester, polyesterimide, polyesteramideimide, polyamideimide and polyimide. Can be given. Of these, a base layer formed by applying or baking a polyamideimide-based paint, a polyesterimide-based paint or a polyester-based paint is preferable.

The film thickness of the underlayer is not particularly limited in the present invention either, but considering the mechanical strength of the film and the like, the ratio of the film thickness between the insulating film and the underlayer is in the range of 1/10 to 10/1. It is preferably within. When the insulating coating is formed directly on the surface of the electric wire, an overcoat layer may be provided on the surface. Examples of the overcoat layer include insulating films formed by coating and baking various conventionally known insulating coating materials such as polyurethane-based, polyester-based, polyesterimide-based, polyesteramideimide-based, polyamideimide-based, and polyimide-based. .

A surface lubrication layer may be provided on the upper surface of the insulating coating in order to impart lubricity to the surface of the insulating coating. As the surface lubricating layer, a coating film of paraffin such as liquid paraffin or solid paraffin can be used, but in consideration of durability etc., various waxes, lubricants such as polyethylene, fluororesin and silicone resin are bound with a binder resin. A surface lubricating layer is more preferred.

[0049]

EXAMPLES The insulated wire of the present invention will be described below based on Examples and Comparative Examples. Example 1 In a flask equipped with a thermometer, a cooling tube, a calcium chloride filling tube, a stirrer, and a nitrogen blowing tube, trimellitic acid anhydride (hereinafter referred to as "TMA" while flowing 150 ml of nitrogen gas per minute from the nitrogen blowing tube. 2) and trimellitic acid (hereinafter referred to as “ETM”)
An approximately equimolar amount of the seed acid component and diphenylmethane-4,4'-diisocyanate (hereinafter referred to as "MDI") as an isocyanate component were added. The content ratio of ETM, which is a polycarboxylic acid compound, with respect to the total amount of the acid component and the isocyanate component was 1.7 mol%.

Next, N as a solvent was placed in the flask.
-Methyl-2-pyrrolidone was added and heated at 80 ° C for 3 hours while stirring with a stirrer, and then 140 ° C over 3 hours.
After heating up to 140 ° C., it was heated at 140 ° C. for 1 hour. And
When 1 hour has passed, stop heating and allow to cool to a concentration of 25
% Polyamide imide-based paint was obtained. This polyamide-imide-based coating material was applied onto a surface of a copper wire having a diameter of 1.0 mm and baked by a conventional method to prepare an insulated electric wire having an insulating coating film having a film thickness of 35 μm.

Example 2 Same as Example 1 except that the charged amounts of TMA and ETM at the time of preparing the polyamide-imide coating composition were changed so that the ratio of ETM to the total amount of the acid component and the isocyanate component was 3.45 mol%. Then, an insulated electric wire was produced. Example 3 Insulation was performed in the same manner as in Example 1 except that the amounts of TMA and ETM prepared during the preparation of the polyamide-imide-based coating material were changed so that the ratio of ETM to the total amount of the acid component and the isocyanate component was 6.45 mol%. An electric wire was produced.

COMPARATIVE EXAMPLE 1 EDM was not charged at the time of preparing a polyamide-imide type coating material, but T
The amount of MA charged is MDI as the isocyanate component.
An insulated electric wire was produced in the same manner as in Example 1 except that the molar amount was substantially equal to. Comparative Example 2 Insulation was performed in the same manner as in Example 1 except that the amounts of TMA and ETM charged during the preparation of the polyamide-imide-based coating material were changed so that the ratio of ETM to the total amount of the acid component and the isocyanate component was 8.7 mol%. An electric wire was produced.

Example 4 EDM was not charged at the time of preparing a polyamide-imide-based coating, and T
The amount of MA charged was approximately equal to that of the isocyanate component, and MDI was used as the isocyanate component and polymeric-4,4'-diphenylmethane diisocyanate (trade name Sumidule 4 manufactured by Sumitomo Bayer Urethane Co., Ltd.).
4V10, hereinafter referred to as “C-MDI”) was used to produce an insulated wire in the same manner as in Example 1.
The content ratio of C-MDI, which is a polyisocyanate compound, to the total amount of the acid component and the isocyanate component was 1.7 mol%.

The following tests were conducted on the insulated wires of the above Examples and Comparative Examples. Flexibility test Insulated wires of Examples and Comparative Examples, from 1 mm in diameter to 1 mm
No damage was observed in the insulation coating when the wires were bent in accordance with the outer shape of the round rod by sequentially applying multiple round rods whose diameters gradually increased. The smallest round bar diameter d (mm) was recorded.

Measurement of Softening Point The softening point (° C.) of the insulating coating was measured by a method according to the method described in JIS C3003 “Test method for enamel copper wire and enamel aluminum wire”. The above results are shown in Table 1.
Shown in.

[0056]

[Table 1]

From the results of Examples 1 to 3 and Comparative Examples 1 and 2 in Table 1 above, the higher the content ratio of ETM as the polycarboxylic acid compound, the higher the softening point and the higher the heat softening resistance of the insulating coating. However, if the content ratio of ETM exceeds 8 mol%, the flexibility of the insulating coating is significantly deteriorated.
It has been found that the content ratio of must be 8 mol% or less. It was also confirmed that, considering the flexibility of the insulating coating, the content ratio of ETM is more preferably 3 mol% or less. From the results of Examples 1 and 4 and Comparative Example 1,
Even if C-MDI is used as the polyisocyanate compound instead of ETM as the polycarboxylic acid compound,
Similarly, it was found that the heat resistance and softening resistance of the insulating coating are improved.

Example 5 In a flask equipped with a thermometer, a cooling tube, a calcium chloride filling tube, a stirrer, and a nitrogen blowing tube, while flowing 150 ml of nitrogen gas per minute from the nitrogen blowing tube, TMA,
Two acid components of ETM and 4,4'-diaminodiphenylmethane (hereinafter referred to as "DDM") as an amine component in an amount of about 1/2 times the total amount of the two acid components were charged.

Next, N-methyl-2 was added to the flask.
-Pyrrolidone was added and heated at 80 ° C for 2 hours while stirring with a stirrer to generate imidodicarboxylic acid. Next, in the above reaction solution, an approximately equimolar amount of M with imidodicarboxylic acid was added.
Add DI and stir with a stirrer at 80 ° C for 2 hours, 1
It was heated at 40 ° C. for 2 hours and further at 180 ° C. for 2 hours, and then allowed to cool to obtain a polyamideimide-based coating material having a solid content concentration of 25%.

Then, an insulated wire was prepared in the same manner as in Example 1 using this polyamide-imide type coating material. The content ratio of ETM with respect to the total amount of the amine component, the acid component and the isocyanate component in the raw material stage was 3.6 mol%. Example 6 EDM was not charged at the time of preparing a polyamide-imide-based coating, and T
The amount of MA charged was approximately twice the molar amount of the amine component, and DDM, 3, 4, 3 ', and
4'-biphenyltetramine (hereinafter referred to as "TAB")
An insulated wire was produced in the same manner as in Example 5 except that and were used. The content ratio of TAB, which is a polyamine compound, with respect to the total amount of the amine component, the acid component and the isocyanate component was 0.85 mol%.

Example 7 EDM was not charged at the time of preparing a polyamide-imide type coating material, and T
The amount of MA charged was approximately twice the molar amount of the amine component, and MDI and C-MDI were used as isocyanate components.
An insulated wire was produced in the same manner as in Example 5 except that and were used. CM which is a polyisocyanate compound
The content ratio of DI to the total amount of the amine component, the acid component and the isocyanate component was 0.85 mol%.

Example 8 TMA, which is an acid component in the preparation of a polyamide-imide type coating material
And the amount of ETM charged, and the amounts of amine components DDM and TAB changed, respectively, and the ratio of ETM to the total amount of amine component, acid component and isocyanate component is 0.85 mol% and the ratio of TAB is 0.425 mol%. An insulated wire was produced in the same manner as in Example 5, except that the total ratio of both was set to 1.275 mol%.

Both the flexibility test and the softening point measurement were conducted on the insulated wires of the above Examples and Comparative Examples. The results are shown in Table 2.

[0064]

[Table 2]

From the results shown in Table 2 above, it is possible to improve the heat resistance and softening resistance of the insulating coating by including the polyfunctional component in the insulated wire using the polyamide-imide type coating produced by the two-step reaction. I understood. Example 9 In a flask equipped with a thermometer, a cooling tube, a calcium chloride filling tube, a stirrer, and a nitrogen blowing tube, while flowing 150 ml of nitrogen gas per minute from the nitrogen blowing tube, TMA,
The two acid components of ETM and MDI and 3,3′-dimethylbiphenyl-in approximately equimolar amounts to the two acid components.
Two isocyanate components of 4,4'-diisocyanate (hereinafter referred to as "TODI") were added. The content ratio of ETM, which is a polycarboxylic acid compound, with respect to the total amount of the acid component and the isocyanate component was 1.7 mol%. The proportion of TODI in the isocyanate component was 20 mol%.

Then, a polyamide-imide type coating material was prepared in the same manner as in Example 1 and was used to prepare Example 1
An insulated electric wire was produced in the same manner as. Example 10 MDI and TODI at the time of producing a polyamideimide-based coating material
An insulated wire was produced in the same manner as in Example 9 except that the proportion of TODI in the isocyanate component was changed to 40 mol%.

Example 11 MDI and TODI at the time of preparing a polyamide-imide type coating material
An insulated wire was produced in the same manner as in Example 9 except that the proportion of TODI in the isocyanate component was changed to 50 mol%. Example 12 MDI and TODI at the time of preparing a polyamide-imide-based coating material
An insulated wire was produced in the same manner as in Example 9 except that the charged amount of was changed to 75 mol% of TODI in the isocyanate component.

Comparative Example 3 ETM was not charged during preparation of the polyamide-imide type coating material, and T
An insulated wire was produced in the same manner as in Example 11 except that the amount of MA charged was substantially equimolar to the amount of the isocyanate component. Comparative Example 4 Do not charge MDI when preparing a polyamide-imide-based coating,
An insulated wire was produced in the same manner as in Example 9 except that the amount of ODI charged was substantially equimolar to the acid component.

Both the flexibility test and the softening point measurement were conducted on the insulated wires of the above Examples and Comparative Examples. The results are shown in Table 3.

[0070]

[Table 3]

From the results shown in Table 3 above, in the system in which the aromatic diisocyanate compound TODI is contained in the isocyanate component in a proportion of 10 to 80 mol%, the constitution of the present invention is employed, whereby the heat softening resistance is improved. It turned out that the decrease can be prevented. It was also found that in a system containing TODI in an isocyanate component in an amount of more than 80 mol%, even if the constitution of the present invention is adopted, it is not possible to prevent a decrease in heat softening resistance.

Example 13 In a flask equipped with a thermometer, a cooling tube, a calcium chloride filling tube, a stirrer, and a nitrogen blowing tube, while flowing 150 ml of nitrogen gas per minute from the nitrogen blowing tube, TMA,
The two acid components of ETM and a molar amount of DDM and 3,3′-dimethyl-about 1/2 times the total amount of the two acid components.
Two kinds of amine components of 4,4'-diaminobiphenyl (hereinafter referred to as "DBRB") were added.

Next, N-methyl-2 was added to the flask.
-Pyrrolidone was added and heated at 80 ° C for 2 hours while stirring with a stirrer to generate imidodicarboxylic acid. Next, in the above reaction liquid, an approximately equimolar amount of M with imidodicarboxylic acid
Add DI and stir with a stirrer at 80 ° C for 2 hours, 1
It was heated at 40 ° C. for 2 hours and further at 180 ° C. for 2 hours, and then allowed to cool to obtain a polyamideimide-based coating material having a solid content concentration of 25%.

Then, an insulated wire was produced in the same manner as in Example 1 using this polyamide-imide type coating material. The content ratio of ETM with respect to the total amount of the amine component, the acid component and the isocyanate component in the raw material stage was 3.6 mol%. The ratio of the DBRB amine component and isocyanate component in the total amount was 50 mol%.

Both the flexibility test and the softening point measurement were conducted on the insulated wire of the above example. The results are shown in Table 4.
Shown in.

[0076]

[Table 4]

From the results of Table 4 above, it is possible to adopt the constitution of the present invention in the system containing DBRB which is an aromatic diamine compound in a proportion of 10 to 80 mol% in the total amount of the amine component and the isocyanate component. It was found that the deterioration of heat softening resistance can be prevented.

[0078]

EFFECTS OF THE INVENTION According to the insulated wire of the present invention, by introducing a polyfunctional group into the structure of polyamide-imide to improve the crosslink density, it is excellent in flexibility and has heat-softening resistance at high temperature. An excellent insulating film can be formed. Therefore, the insulated wire of the present invention is particularly excellent in heat resistance, and when it is used, for example, in winding of a motor, even if the winding amount to the core is increased more than before, there is no risk of a rare short even at high temperature, It is possible to meet the demand for smaller and lighter motors with better performance.

Claims (4)

[Claims] 1. In an insulated wire having an insulating coating formed by applying and baking a polyamideimide-based coating material containing an isocyanate component containing at least a diisocyanate compound and an acid component as raw materials, the isocyanate component and the acid component as the raw materials are Polyfunctional polyisocyanate compound having three or more isocyanate groups and at least one polyfunctional polycarboxylic acid compound having three or more carboxylic acid groups, and the total amount of isocyanate component and acid component The total content of these polyisocyanate compounds and polycarboxylic acid compounds is 0.5 to 8 mol%. 2. An isocyanate component is represented by the following general formula (1): [In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom.
m and n are the same or different and represent a number of 1 to 4. ] The insulated electric wire of Claim 1 containing the aromatic diisocyanate compound represented by these in the ratio of 10-80 mol%. 3. An imidodicarboxylic acid which is a reaction product of an amine component containing at least a diamine compound and an acid component,
Application of a polyamide-imide-based coating material having an isocyanate component containing at least a diisocyanate compound as a raw material,
In an insulated wire having an insulating coating formed by baking, an amine component, an acid component and an isocyanate component as raw materials are polyfunctional polyamine compounds having 3 or more amino groups and polyfunctional polyamine compounds having 3 or more carboxylic acid groups. Functional polycarboxylic acid compound and at least one kind of polyfunctional polyisocyanate compound having three or more isocyanate groups, and these polyamine compound, polycarboxylic acid based on the total amount of amine component, acid component and isocyanate component An insulated wire, wherein the total content of the acid compound and the polyisocyanate compound is 0.5 to 8 mol%. 4. An amine component and an isocyanate component,
The following general formula (2): [In the formula, R ³ and R ⁴ are the same or different and each represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom.
p and q are the same or different and represent a number of 1 to 4. ] An aromatic diamine compound represented by, and at least one of the aromatic diisocyanate compound represented by the general formula (1), and an amine component as a raw material, relative to the total amount of the isocyanate component, these aromatic An insulated wire, wherein the total content of the diamine compound and the aromatic diisocyanate compound is 10 to 80 mol%.