JP3497525B2 - Insulated wire - Google Patents

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.

Namely insulated wire of the present invention, in the insulated wire having a polyamide coating of imide coatings, insulating coatings formed by baking to the isocyanate component and an acid component as a raw material comprising at least a diisocyanate compound, the polyamideimide As the coating material, at least one of a polyfunctional polyisocyanate compound having three or more isocyanate groups and a polyfunctional polycarboxylic acid compound having three or more carboxylic acid groups is added in total.
And 0.5 in the total amount of the isocyanate component and the acid component.
In a proportion of up to 8 mol% and containing 3,3'-dimes
Cylbiphenyl-4,4'-diisocyanate
10 to 80 mol% of cyanate component
Isocyanate component and acid component together with solvent 140
After heating at a temperature below ℃ for a certain time, raise the temperature and
It is characterized in that it was synthesized by heating for a certain period of time .

Another insulated wire according to the present invention is a polyamide-imide based coating material containing imidedicarboxylic acid which is a reaction product of an amine component which is a diamine compound and an acid component, and an isocyanate component which contains at least a diisocyanate compound. In an insulated wire having an insulating coating formed by coating and baking, the acid component and the isocyanate component as raw materials contain a polyfunctional polycarboxylic acid compound having three or more carboxylic acid groups and three or more isocyanate groups. An amine component containing at least one of the polyfunctional polyisocyanate compounds having
The total content of the polycarboxylic acid compound and the polyisocyanate compound is 0.5 to 8 mol% with respect to the total amount of the acid component and the isocyanate component.

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%.

Specifically, in the present invention, (a) an isocyanate component as a raw material contains a polyisocyanate compound, (a) an acid component as a raw material contains a polycarboxylic acid compound, and (c) a raw material There are three cases in which the polyisocyanate compound is contained in the isocyanate component and the polycarboxylic acid compound is contained in the acid component. In the case of (a) , the polyisocyanate compound is contained with respect to the total amount of the isocyanate component and the acid component. The ratio is limited to 0.5 to 8 mol%, (a)
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 (c) , the polyisocyanate compound is contained with respect to the total amount of the isocyanate component and the acid component. , The total content of polycarboxylic acid compounds is 0.5 to
Limited to 8 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.

In the invention according to claim 1 , the polyisocylate is
Included in the isocyanate component along with the anate compound
Other isocyanates include the formula (1a) :

[0017]

[Chemical 4]

3,3'-dimethylbiphenyl represented by
Diiso containing at least 4,4'-diisocyanate
Cyanate compounds are essential for obtaining polyamideimide.
It is an ingredient of broth. The above 3,3'-dimethylbiphenyl-
For the isocyanate component of 4,4'-diisocyanate
The content ratio with respect to
Considering to prevent deterioration of heat resistance of edge coating
And 10 to 80 mol%. That is, including the above
If the proportion is less than 10 mol%, 3,3'-dimethylbiph
Containing phenyl-4,4'-diisocyanate
Therefore, the effect of increasing the strength of the insulating coating cannot be obtained. Well
If it exceeds 80 mol%, the polyfunctional component
Even if it is contained in the above content ratio,
The chemical conversion decreases.

The above 3,3'-dimethylbiphenyl-4,
As the diisocyanate compound other than 4'-diisocyanate , an aromatic diisocyanate having an aromatic ring in its structure is particularly preferably used. Examples of aromatic diisocyanates include diphenylmethane-4,
4'-diisocyanate, diphenylmethane-3,3 '
-Diisocyanate, diphenylmethane-3,4'-diisocyanate, diphenylether-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
-Various conventionally known compounds such as xylylene diisocyanate can be used. These may be used alone or in combination of two or more.

The invention according to claim 3 is also used.
The following general formula (1):

[0021]

[Chemical 5]

[ Wherein R ¹ and R ² are the same or different,
Hydrogen atom, alkyl group, alkoxy group or halogen source
Indicates a child. m and n are the same or different and represent a number of 1 to 4.
You ] Specific examples of the aromatic diisocyanate compound represented by the above include 3,3'-dimethylbiphenyl-4,
Most preferred is 4'-diisocyanate, but others such as biphenyl-4,4'-diisocyanate, 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,
Examples thereof include 2'-diethoxybiphenyl-4,4'-diisocyanate and 2,3'-diethoxybiphenyl-4,4'-diisocyanate. These may be used alone or in combination of two or more.

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
Time , more specifically, constant at a temperature below 140 ° C
After heating for a period of time, the temperature is raised and further heated for a certain period of time to cause a reaction, whereby polyamideimide, which is a copolymer of an isocyanate component and an acid component, is dissolved or dispersed in an organic solvent. An imide-based paint 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. As the polyfunctional polycarboxylic acid compound and the polyisocyanate compound contained in the acid component and the isocyanate component as the raw materials, the above-exemplified various compounds can be mentioned. In the present invention, the amine component as a raw material, the acid component and the isocyanate component contain at least one of the polycarboxylic acid compound and the polyisocyanate compound, and to the total amount of the amine component, the acid component, the isocyanate component, The total content of these polycarboxylic acid compounds and polyisocyanate compounds is limited to 0.5 to 8 mol%.

More specifically, in the present invention, (a) an acid component as a raw material contains a polycarboxylic acid compound, (a) an isocyanate component as a raw material contains a polyisocyanate compound, (c) as a raw material There are three cases in which the polycarboxylic acid compound is contained in the acid component and the polyisocyanate compound is contained in the isocyanate component. In the case of (a) , the polycarboxylic acid relative to the total amount of the amine component, the acid component and the isocyanate component is included. The content ratio of the acid compound is limited to 0.5 to 8 mol%, and in the case of (a) , the content ratio of the polyisocyanate compound is limited to 0.5 to 8 mol% with respect to the total amount of the above three components.

In the case of (c) , the total content of the polycarboxylic acid compound and the polyisocyanate compound is limited to 0.5 to 8 mol% with respect to the total amount of the above three components.

When 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 in the range of 0.5 to 3 mol%, especially in the above range.
As the amine component, 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):

[0034]

[Chemical 7]

[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) in a proportion of 10 to 80 mol% in the total amount of the amine component and the isocyanate component, While it is suitable 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 addition, in the system containing the aromatic diamine compound and the aromatic diisocyanate 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 is 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.

[0038]

[Chemical 8]

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, those 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 in consideration of the mechanical strength of the film, 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. .

Further, a surface lubricating 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.

[0046]

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”)
Species acid component and approximately equimolar amounts, diphenylmethane -4,
4'-diisocyanate (hereinafter referred to as "MDI") and
And 3,3'-dimethylbiphenyl-4,4'-diisocyanate
Two types of isocyanate, anate (hereinafter referred to as "TODI")
And nate ingredients . 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%. Also of TODI
The proportion in the isocyanate component is 20 mol%
It was

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 MDI and TODI at the time of preparing a polyamide-imide type coating material
Changing the charged amount, in the isocyanate component of TODI
Except that the proportion of 40 mol% was prepared insulated wire in the same manner as in Example 1. Example 3 MDI and TODI at the time of producing a polyamide-imide-based coating material
Changing the charged amount, in the isocyanate component of TODI
An insulated wire was produced in the same manner as in Example 1 except that the proportion occupied was 50 mol%. Example 4 MDI and TODI at the time of preparing a polyamide-imide-based paint
Change the charge amount of
Example 1 except that the proportion occupied was 75 mol%.
An insulated wire was produced in the same manner.

Comparative Example 1 ETM was not charged during preparation of the polyamide-imide type coating, and T
The charge of MA, except that a substantially equimolar amount min isocyanate formed, to prepare an insulated wire in the same manner as in Example 3. Comparative Example 2 When preparing a polyamide-imide-based paint, do not charge MDI
An insulated wire was produced in the same manner as in Example 1 except that the amount of ODI charged was substantially equimolar to the acid component .

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.

[0052]

[Table 1]

From the results shown in Table 1 above , the aromatic diisocyanate was obtained.
Of TODI, which is a salt compound, in the isocyanate component
In a system containing 10 to 80 mol%, the composition of the present invention is
By adopting the composition, it is possible to prevent the deterioration of heat softening resistance.
I understood. In addition, TODI in the isocyanate component
In a system containing more than 80 mol% of
Even if it is adopted, it may not be possible to prevent deterioration in heat softening resistance.
It was

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, using this polyamide-imide type coating material, an insulated wire was prepared in the same manner as in Example 1. 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 ETM 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 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%.

Both the flexibility test and the softening point measurement were conducted on the insulated wire of each of the above examples. The results are shown in Table 2.

[0059]

[Table 2]

From the results shown in Table 2 above, it is possible to improve the heat resistance and softening property 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 7 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 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, using this polyamide-imide type coating material, an insulated wire was prepared in the same manner as in Example 1. 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 3.
Shown in.

[0065]

[Table 3]

From the results shown in Table 3 above, 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, the constitution of the present invention was adopted. It was found that the deterioration of heat softening resistance can be prevented.

[0067]

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.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01B 3/16-3/56 H01B ^7/ 00-7/02 H01B ^7/ 30-7/36

Claims (3)

(57) [Claims] 1. A least diisocyanate compound coating of polyamideimide paint an isocyanate component and an acid component as a raw material containing, in insulated wire having an insulating coating formed by baking, the polyamideimide paint
As the material, at least one of a polyfunctional polyisocyanate compound having three or more isocyanate groups and a polyfunctional polycarboxylic acid compound having three or more carboxylic acid groups is added in total to form an isocyanate component and an acid component. Total amount of
In addition to the content of 0.5 to 8 mol% in the
3'-Dimethylbiphenyl-4,4'-diisocyanate
Of the isocyanate component in the proportion of 10 to 80 mol%
With the isocyanate component and the acid component contained in, with a solvent
After heating at a temperature below 140 ° C for a certain period of time, then raising the temperature
Then , an insulated electric wire characterized in that it is obtained by heating and synthesizing for a certain period of time . 2. Formed by coating and baking a polyamideimide-based coating material containing imidedicarboxylic acid which is a reaction product of an amine component which is a diamine compound and an acid component, and an isocyanate component which contains at least a diisocyanate compound. In an insulated wire having an insulating coating, an acid component and an isocyanate component as raw materials are a polyfunctional polycarboxylic acid compound having three or more carboxylic acid groups and a polyfunctional polyisocyanate compound having three or more isocyanate groups. The content ratio of the total of these polycarboxylic acid compounds and polyisocyanate compounds is 0.5 to 8 mol% based on the total amount of the amine component, the acid component, and the isocyanate component containing at least one of them.
Insulated wire characterized by being. 3. 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. ] And an aromatic diamine compound represented by the general formula (1) : [Wherein R ¹ and R ² are the same or different and each represents a hydrogen atom,
It represents a 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. ] At least one of the aromatic diisocyanate compounds represented by, and the total content ratio of these aromatic diamine compounds and aromatic diisocyanate compounds with respect to the total amount of amine components and isocyanate components as raw materials is 10-80 3. The composition according to claim 2, wherein the content is mol%.
Placing insulated wire.