JPH0636616A - Insulated wire - Google Patents

Abstract

PURPOSE:To provide an insulated wire of high processability resistance having an insulation coat of high flexibility and damage resistance by using a specific aromatic diamine compound as the diamine component of a polyimide compound in a polyimide insulation paint. CONSTITUTION:Regarding an insulated wire having an insulation coat formed through the application and subsequent baking of polyimide paint, at least one of aromatic diamine compounds expressed by the formulae I, II and Ill is used by a ratio of 10 to 80mol% for a total raw material diamine component as a diamine component to constitute polyimide. R<1> in the formula I stands for a hydrogen atom, an alkyl group, an alkoxyl group or a halogen atom, and (n) for a numeral between 1 and 4. R<2> and R<3> in the formula II stand identically or differently for a hydrogen atom, an alkyl group, an alkoxyl group or a halogen atom, and (p) and (q) identically or differently for a numeral between 1 and 4. R<4> and R<5> in the formula II are the same as R<2> and R<3> in the formula II, and (r) and (s) stand identically or differently for a numeral between 1 and 4.

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, the following formula (IV)
The reaction product of diphenylmethane-4,4'-diisocyanate represented by and trimellitic anhydride is generally used (see, for example, JP-B-44-19274 and JP-B-45-27611). ).

[0004]

[Chemical 4]

[0005]

However, in recent years, motors having smaller size, lighter weight and better performance have been required, and in order to meet the demand, the winding amount of the insulated wire tends to further increase. However, the damage is increasing. Therefore, in order to reduce the damage of the insulating coating as much as possible, it has been studied to add a lubricant such as an organic or inorganic lubricant to the coating to impart lubricity to the surface of the insulating coating. However, damage to the insulating coating cannot be fundamentally resolved.

Although the occurrence of damage can be reduced by further improving the mechanical strength of the insulating coating, if the mechanical strength is simply improved, the coating becomes rigid and inferior in flexibility, and when the electric wire is bent. There is a problem that the workability of the insulated electric wire deteriorates because it is easily cracked or peeled off. The present invention is
The present invention has been made in view of the above circumstances, and an object thereof is to provide an insulated electric wire that has an insulating coating film that is excellent in flexibility and is not easily damaged, and that is excellent in work resistance.

[0007]

In order to solve the above-mentioned problems, the present inventors have replaced the conventional polyamide-imide-based paint with a polyimide having a structure of benzene, biphenyl or benzanilide introduced into the structure. It has been found that the use of a paint of the type improves the elastic modulus of the insulating coating, and that an insulating coating having excellent flexibility and being less likely to be damaged can be formed, and has completed the present invention. That is, the insulated wire of the present invention, an acid coating containing at least a tetracarboxylic dianhydride, and a polyimide coating composition containing a polyimide composed of a polyimide or a precursor of a diamine component, or a polyamic acid as a precursor thereof, an insulating coating formed by baking. In the insulated wire having a diamine component as a raw material, the following general formula (I):

[0008]

[Chemical 5]

[In the above formula, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. n is 1
The number of 4 is shown. ], The following general formula (II):

[0010]

[Chemical 6]

[In the above formula, R ² and R ³ 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 the following general formula (III):

[0012]

[Chemical 7]

[In the above formula, R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. r and s are the same or different and each represents a number of 1 to 4. ] It contains at least 1 sort (s) of the aromatic diamine compound represented by these, and the total content rate of these aromatic diamine compounds in the diamine component as a raw material is 10-80 mol%, It is characterized by the above-mentioned. .

Among the diamine components which are one of the raw materials for polyimide coatings, the aromatic diamine compound represented by the general formula (I) is represented by the following general formula (Ia):

[0015]

[Chemical 8]

[Wherein R ¹ represents the same group as described above, and n
Is 1 to 4. ] The p-phenylenediamine derivative represented by the following is preferably used. Specific examples of the p-phenylenediamine derivative include, for example, p-phenylenediamine, 2-methyl-p-phenylenediamine, 2-ethyl-p-phenylenediamine, 2-methoxy-p-phenylenediamine, 2-ethoxy-p-. Examples thereof include phenylenediamine, 2-chloro-p-phenylenediamine and 2-bromo-p-phenylenediamine. These may be used alone or in combination of two or more.

As the aromatic diamine compound represented by the above general formula (I), m-phenylenediamine and its derivative, o-phenylenediamine and its derivative and the like can be used. Among the above aromatic diamine compounds, in terms of availability and cost, the following formula
The p-phenylenediamine represented by (1) is most preferably used in the present invention.

[0018]

[Chemical 9]

Specific examples of the aromatic diamine compound represented by the general formula (II) 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 (2) is the present invention in view of availability and cost. Most preferably used.

[0021]

[Chemical 10]

Specific examples of the aromatic diamine compound represented by the general formula (III) include, for example, 4,4'-diaminobenzanilide, 3,4'-diaminobenzanilide and 3,3'-diaminobenzanilide. 2'-methyl-4,4'-diaminobenzanilide, 3'-methyl-
4,4'-diaminobenzanilide, 2,2'-dimethyl-4,4'-diaminobenzanilide, 3,2'-dimethyl-4,4'-diaminobenzanilide, 3,3 '
-Dimethyl-4,4'-diaminobenzanilide, 2 '
-Ethyl-4,4'-diaminobenzanilide, 3'-
Ethyl-4,4'-diaminobenzanilide, 2'-methoxy-4,4'-diaminobenzanilide, 3'-methoxy-4,4'-diaminobenzanilide, 2,2 '
-Dimethoxy-4,4'-diaminobenzanilide,
3,2'-dimethoxy-4,4'-diaminobenzanilide, 3,3'-dimethoxy-4,4'-diaminobenzanilide, 2'-ethoxy-4,4'-diaminobenzanilide, 3'-ethoxy -4,4'-Diaminobenzanilide, 2'-chloro-4,4'-diaminobenzanilide, 2,2'-dichloro-4,4'-diaminobenzanilide, 2'-bromo-4,4'- Examples include diaminobenzanilide and 2,2′-dibromo-4,4′-diaminobenzanilide. These may be used alone or in combination of two or more.

Among the above aromatic diamine compounds, 4,4'-diaminobenzanilide represented by the following formula (3) is most preferably used in the present invention in view of availability and cost. It

[0024]

[Chemical 11]

As the other diamine contained in the diamine component together with the aromatic diamine compound represented by the general formula (I), (II) or (III), 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'-
Examples thereof include various conventionally known diamine compounds such as [bis (4-aminophenoxy)] diphenylhexafluoropropane. These may be used alone or in combination of two or more.

Among the above diamine compounds, 4,4'-diaminodiphenyl ether is preferably used from the viewpoint of enhancing the strength of the insulating coating. In the present invention, the general formula
The ratio of the aromatic diamine compound represented by (I), (II) or (III) in the diamine component is limited to 10 to 80 mol%. More specifically, when any one of the above aromatic diamine compounds is contained alone in the diamine component, the proportion of the diamine component in the diamine component is limited to 10 to 80 mol%. Moreover, when using 2 or more types of said each aromatic diamine compound together, the total ratio is limited to 10-80 mol%.

The ratio of the aromatic diamine compound is 10 mol%
If it is less than the above range, the effect of adding the aromatic diamine compound cannot be obtained, and the insulating coating tends to be damaged. On the other hand, when the proportion of the aromatic diamine compound exceeds 80 mol%, the insulating coating is rigid and inferior in flexibility, and is likely to be cracked or peeled. The ratio of the aromatic diamine compound in the diamine component is preferably in the range of 30 to 70 mol%, especially in the above range.

Tetracarboxylic acid dianhydride is mainly used as an acid component which constitutes the polyimide coating material together with the diamine component. Specific examples of the tetracarboxylic dianhydride include, for example, pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, diphenylsulfonetetracarboxylic dianhydride, diphenylmethanetetracarboxylic acid. Examples thereof include dianhydride, diphenylpropanetetracarboxylic acid dianhydride, diphenylhexafluoropropanetetracarboxylic acid dianhydride, benzenetetracarboxylic acid dianhydride and naphthalenetetracarboxylic acid dianhydride. These may be used alone or in combination of two or more.

Among the above-mentioned tetracarboxylic dianhydrides, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride is preferably used from the viewpoint of enhancing the strength of the insulating coating. Further, in the acid component, among the derivatives of tetracarboxylic dianhydride, trimellitic acid, trimellitic anhydride, trimellitic acid chloride, and trimellitic acid derivatives, as long as the characteristics of the insulating coating are not impaired. Tribasic acid, terephthalic acid, isophthalic acid, sulfoterephthalic acid, dicitric acid, 2,5-thiophenedicarboxylic acid, 4,5-phenanthrenedicarboxylic acid, benzophenone-4,4'-dicarboxylic acid, phthaldiimidedicarboxylic acid, biphenyl A part of dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, adipic acid or the like may be added.

In order to produce the polyimide coating used in the present invention from the above diamine component and acid component, for example, a substantially stoichiometric amount of diamine component and acid component are copolymerized in a suitable organic solvent. The same manufacturing method as that of the conventional polyimide-based paint can be adopted. More specifically,
The diamine component prepared by blending the aromatic diamine compound represented by the general formula (I), (II) or (III) in the above-mentioned proportion, together with an approximately equimolar amount of the acid component, in a suitable organic solvent at 0 to 60 ° C.
When the reaction is performed at the temperature of 1 to 24 hours, a polyamic acid as a polyimide precursor, which is a reaction product of a diamine component and an acid component, is dissolved or dispersed in an organic solvent to obtain a polyimide-based coating material.

A paint containing this polyamic acid is used in an amount of 0 to
When the reaction is carried out at a temperature of 200 ° C. for 1 to 24 hours, a polyimide-based coating material in which polyimide, which is a dehydration reaction product of polyamic acid, is dissolved or dispersed in an organic solvent is obtained. The insulating coating of the insulated wire of the present invention, the latter polyimide-based coating applied to the surface of the wire, other than formed by baking, the former, the coating containing a polyamic acid as a precursor is applied to the surface of the wire, It can also be formed by baking. In this case, the dehydration ring closure reaction of the polyamic acid is also carried out at the time of baking.

The polyimide-based paint used in the present invention includes a diamine component containing an aromatic diamine compound represented by the general formula (I) (II) or (III) in an amount exceeding the above range, A polyimide-based coating material produced using an acid component as a raw material (as described above, any of those containing polyimide, or one containing polyamic acid as a precursor thereof) and an aromatic diamine compound are not contained, or A mixture of a polyimide-based coating produced from a raw material containing a diamine component and an acid component contained in a very small amount less than the range (also, one containing a polyimide or one containing a polyamic acid as a precursor thereof) It can be used. In this case, the blending ratio of both paints may be adjusted so that the ratio of the aromatic diamine compound in the total diamine component as the raw material falls within the above range.

If necessary, various additives such as pigments, dyes, inorganic or organic fillers and lubricants may be added to the polyimide coating used in the present invention. The insulated wire of the present invention is manufactured by applying the above-mentioned polyimide-based paint to the surface of the wire 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.

A base layer made of a material having good adhesion to the insulating coating and the electric wire may be provided as a lower layer of the insulating coating. Examples of the underlayer 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. Among them, from the viewpoint of adhesion to electric wires and insulating coatings, mechanical strength of coatings, etc., it is formed by coating and baking a polyamideimide-based coating material containing diphenylmethane-4,4'-diisocyanate and trimellitic anhydride. The underlying layer is preferably used.

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 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. A surface lubricating layer may be provided on the upper layer 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 used as binder resins. A bound surface lubricating layer is more preferred.

[0037]

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, while flowing 150 ml of nitrogen gas per minute from the nitrogen blowing tube, 0.5
Mol of pyromellitic dianhydride (hereinafter referred to as "PMDA"), 0.1 mol of p-phenylenediamine (hereinafter referred to as "p-PDA"), and 0.4 mol of 4,4'-diaminodiphenyl ether ( Hereinafter referred to as "DDE"). The ratio of p-PDA in all diamines was 20 mol%.

Next, N-methyl-2-pyrrolidone was placed in the flask so that the solid content concentration was 16%, and the mixture was heated with stirring at 60 ° C. for 5 hours and then left to cool. A polyimide coating material containing polyamic acid as a polyimide precursor was obtained. This polyimide paint,
A copper wire having a diameter of 1.0 mm was coated and baked by a conventional method to prepare an insulated electric wire having an insulating coating having a film thickness of 35 μm.

Example 2 The amounts of p-PDA and DDE charged during the preparation of the polyimide coating were p-PDA = 0.25 mol and DDE = 0.2.
5 mol, the ratio of p-PDA in all diamines is 50
An insulated wire was produced in the same manner as in Example 1 except that the content was mol%.

Example 3 The amounts of p-PDA and DDE charged during the preparation of a polyimide coating were p-PDA = 0.35 mol and DDE = 0.1.
5 mol, the ratio of p-PDA in the total diamine is 70
An insulated wire was produced in the same manner as in Example 1 except that the content was mol%.

Comparative Example 1 p-PDA was not charged at the time of preparing a polyimide-based paint, and DD was used.
An insulated wire was produced in the same manner as in Example 1 except that 0.5 mol of E was charged. Comparative Example 2 p-PD
An insulated wire was produced in the same manner as in Example 1 except that 0.5 mol of A was charged.

Example 4 An insulated wire was prepared in the same manner as in Example 2 except that 0.5 mol of biphenyltetracarboxylic dianhydride (hereinafter referred to as "s-BPDA") was used instead of PMDA. It was made. Example 5 An insulated wire was produced in the same manner as in Example 2 except that 0.25 mol of 4,4′-diaminodiphenylmethane (hereinafter referred to as “DDM”) was used instead of DDE.

Example 6 On a surface of a copper wire having a diameter of 1.0 mm, diphenylmethane-4,
Commercially available polyamide-imide-based coating containing 4'-diisocyanate and TMA (Hitachi Chemical Co., Ltd., product number HI-400)
Was applied and baked by a conventional method to form an underlayer having a film thickness of 8 μm. Next, the same polyimide-based coating material used in Example 2 was applied onto this underlayer by a conventional method and baked to form an insulating coating film having a film thickness of 27 μm, thereby producing an insulated wire.

Example 7 The polyimide-based coating composition containing only DDE as the diamine component prepared in Comparative Example 1 and the polyimide-based coating composition containing only p-PDA as the diamine component prepared in Comparative Example 2 were prepared at the raw material stage. The molar ratio of p-PDA to DDE is p-
It was blended so that PDA / DDE = 50/50 and sufficiently stirred and mixed to prepare a polyimide-based coating material. And
An insulated electric wire was produced in the same manner as in Example 2 using this polyimide coating material.

Example 8 A baking type water-soluble lubricating coating (manufactured by Toshiba Chemical Co., product number TEC-960) was formed on the insulating coating of the insulated wire prepared in Example 2.
An insulated wire was produced in the same manner as in Example 2 except that 1) was applied and baked by a conventional method to form a surface lubricating layer. 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, 0.5
Mol s-BPDA, 0.1 mol p-PDA,
0.4 mol of DDE was added. The ratio of p-PDA in all diamines was 20 mol%.

Next, 4-chlorophenol was added to the above flask so that the solid content concentration became 16%, and the mixture was heated at 60 ° C. for 2 hours while stirring with a stirrer, and further 170 ° C.
After heating for 2 hours at room temperature, it was allowed to cool to obtain a polyimide-based coating in which polyamic acid was imidized. Then, using this polyimide-based coating material, an insulated electric wire was produced in the same manner as in Example 1.

The following tests were carried out on the insulated wires of the above Examples and Comparative Examples. Elastic Modulus Measurement Copper wires were removed by etching from the insulated electric wires of Examples and Comparative Examples, and the remaining insulating coating (length 6 cm) was pulled using a tensile tester under the conditions of a chuck spacing of 3 cm and a pulling speed of 1 mm / min. Elastic modulus (kg / mm ² ) from the SS curve obtained by testing
I asked.

Flexibility test Insulated electric wires of Examples and Comparative Examples were manufactured with a diameter of 1 mm 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.

Rapid extension cutting test The insulated electric wires of Examples and Comparative Examples were rapidly pulled from both ends,
After being rapidly stretched and cut, the floating amount (mm) of the coating film from the copper wire at the cut portion was measured. Piano wire damage load measurement The wires are stacked orthogonally to the insulated wires of the examples and comparative examples, the piano wires are pulled out with various weights applied to the piano wires, and the load that damages the insulation coating is recorded. did.

The above results are shown in Table 1.

[0051]

[Table 1]

From the results in Table 1 above, in the insulated wire of Comparative Example 1 containing no p-PDA as the diamine component, the elastic modulus of the insulation coating was low, and the results of measurement of piano wire damage load revealed that the insulation coating was damaged. I found it easy to do. On the other hand, in the insulated wire of Comparative Example 2 in which the diamine component was 100% p-PDA, the coating film was peeled off from the wire during the baking step, and the insulating coating could not be formed.

On the other hand, all of the insulated wires of Examples 1 to 3 are not easily damaged and have excellent flexibility, and
It was found to have an insulating coating that was difficult to peel off from the copper wire. Further, from the results of each of the above examples, the higher the proportion of p-PDA, the higher the elastic modulus of the insulating coating and the less likely the insulating coating is damaged, but the flexibility and adhesion of the insulating coating , P-
It was found that the lower the proportion of PDA, the better.

Comparing the results of Example 2 and Example 4 in which the proportion of p-PDA is the same, both show almost the same characteristics. From this, PMDA and s
It has been found that -BPDA gives the insulating coating substantially similar properties. Similarly, when the results of Example 2 and Example 5 in which the proportion of p-PDA is the same are compared, both show almost the same characteristics, and from this, as another diamine component used in combination with p-PDA. DDE and DDM of
It has been found that it gives almost the same characteristics to the insulating coating.

Further, comparing the results of Example 2 and Example 6 in which the proportion of p-PDA is the same, since Example 6 has a smaller floating amount of the insulating coating by the rapid elongation cutting test than Example 2, It was found that by forming the underlayer, the adhesiveness of the coating can be further improved while maintaining other properties as they are. In addition, when the results of Example 2 and Example 7 in which the proportion of p-PDA is the same are compared, both exhibit almost the same characteristics, and from this, it is clear that the polyimide-based coating is a mixture of those containing p-PDA and those not containing p-PDA. It was found that the same result as that of the coating material produced by the copolymerization can be obtained even when it is produced by.

Comparing the results of Example 2 and Example 8 in which the proportion of p-PDA is the same, the formation of the surface lubrication layer on the insulating coating allows the insulating coating to be formed while maintaining other characteristics. It turns out that it can be made more difficult to damage.
Furthermore, from the results of Example 9, even when using a polyamic acid as a polyimide precursor, further using an imidized coating, it is less likely to be damaged, and is excellent in flexibility,
It has been found that it is possible to form an insulating coating that is difficult to peel from the copper wire.

Example 10 Example 1 was repeated except that 0.1 mol of 3,3'-dimethyl-4,4'-diaminobiphenyl (hereinafter referred to as "DBRB") was used instead of p-PDA. An insulated electric wire was produced in the same manner as. Example 11 Charge amounts of DBRB and DDE at the time of preparing a polyimide-based coating material were DBRB = 0.25 mol, DDE = 0.25 mol, and the ratio of DBRB in all diamines was 50 mol%.
An insulated wire was produced in the same manner as in Example 10 except that the above was adopted.

Example 12 The amounts of DBRB and DDE charged during the preparation of a polyimide coating were DBRB = 0.35 mol, DDE = 0.15 mol, and the ratio of DBRB to all diamines was 70 mol%.
An insulated wire was produced in the same manner as in Example 10 except that the above was adopted. Comparative Example 3 Do not charge DDE when preparing a polyimide-based coating, and use DBRB
An insulated wire was produced in the same manner as in Example 10 except that 0.5 mol of was added.

Example 13 An insulated wire was prepared in the same manner as in Example 11 except that 0.5 mol of biphenyltetracarboxylic dianhydride (hereinafter referred to as "s-BPDA") was used instead of PMDA. It was made. Example 14 An insulated wire was produced in the same manner as in Example 11 except that 0.25 mol of 4,4′-diaminodiphenylmethane (hereinafter referred to as “DDM”) was used instead of DDE.

Example 15 On the surface of a copper wire having a diameter of 1.0 mm, the same polyamideimide coating as used in Example 6 was applied by a conventional method and baked to form an underlayer having a thickness of 8 μm. Next, the same polyimide-based coating material used in Example 11 was applied onto this underlayer by a conventional method and baked to give a film thickness of 27 μm.
The insulating coating of was formed to produce an insulated wire.

With respect to the insulated wires of the above Examples and Comparative Examples, the elastic modulus measurement, the flexibility test, the rapid extension cutting test and the piano wire damage load measurement were conducted. The above results are shown in Table 2 together with the result of Comparative Example 1 corresponding to the case where DBRB was not mixed as the diamine component.

[0062]

[Table 2]

From the results shown in Table 2 above, the diamine component was 10
In the insulated wire of Comparative Example 3 having 0% DBRB, the flexibility of the insulation coating was poor according to the results of the flexibility test, and the insulation coating was likely to be easily peeled off from the copper wire according to the results of the rapid elongation cutting test. understood. On the other hand, all of the insulated wires of Examples 10 to 12 are hard to be damaged and have excellent flexibility, and
It was found to have an insulating coating that was difficult to peel off from the copper wire. Further, from the results of each of the above examples, the higher the ratio of DBRB, the higher the elastic modulus of the insulating coating and the more difficult the insulating coating is to be damaged.
It was found that the lower the ratio of B, the more preferable.

Comparing the results of Example 11 and Example 13 in which the proportion of DBRB is the same, the two show almost the same characteristics. From this, PMDA and s-BPDA as acid components are It has been found that they give almost the same characteristics to. Similarly, when the results of Example 11 and Example 14 in which the proportion of DBRB is the same are compared, both show almost the same characteristics, which indicates that DDE and DDM as other diamine components used in combination with DBRB are obtained.
Has been found to give the insulating coating almost the same characteristics.

Furthermore, Example 11 in which the ratio of DBRB is the same.
Comparing the results of Example 15 with Example 15, since Example 15 has a smaller floating amount of the insulating coating in the rapid elongation cutting test than Example 11, by forming the underlayer, other characteristics are maintained as they are. However, it was found that the adhesion of the coating can be further improved. Example 16 An insulated wire was produced in the same manner as in Example 1 except that 0.1 mol of 4,4′-diaminobenzanilide (hereinafter referred to as “DABAN”) was used instead of p-PDA. .

Example 17 DABAN = 0.25 mol and DDE = 0.2 were set as the charging amounts of DABAN and DDE at the time of preparation of the polyimide coating material.
5 mol, the ratio of DABAN in the total diamine is 50
An insulated wire was produced in the same manner as in Example 16 except that the mol% was set.

Example 18 DABAN and DDE were charged at the time of preparing a polyimide-based coating material so that DABAN = 0.35 mol and DDE = 0.1.
5 mol, the ratio of DABAN in the total diamine is 70
An insulated wire was produced in the same manner as in Example 16 except that the mol% was set.

Comparative Example 4 DABA was not charged at the time of preparing a polyimide-based coating, and DABA was used.
An insulated wire was produced in the same manner as in Example 16 except that 0.5 mol of N was charged. Example 19 An insulated wire was produced in the same manner as in Example 17 except that 0.5 mol of biphenyltetracarboxylic dianhydride (hereinafter referred to as “s-BPDA”) was used instead of PMDA.

Example 20 An insulated wire was prepared in the same manner as in Example 17 except that 0.25 mol of 4,4'-diaminodiphenylmethane (hereinafter referred to as "DDM") was used instead of DDE. . Example 21 A copper wire having a diameter of 1.0 mm was coated with the same polyamideimide-based coating material as used in Example 6 by a conventional method and baked to form an underlayer having a thickness of 8 μm.

Next, the same polyimide-based coating material used in Example 17 was applied onto this underlayer by a conventional method and baked to form an insulating coating film having a thickness of 27 μm, to produce an insulated wire. With respect to the insulated wires of the above Examples and Comparative Examples, the elastic modulus measurement, the flexibility test, the rapid extension cutting test and the piano wire damage load measurement were performed. The above results are shown in Table 3 together with the results of Comparative Example 1 corresponding to the case where DABAN was not blended as the diamine component.

[0071]

[Table 3]

From the results shown in Table 3 above, the diamine component was 10
The insulated wire of Comparative Example 4 containing 0% DABAN had poor flexibility of the insulating coating according to the result of the flexibility test, and the insulating coating was likely to be easily separated from the copper wire according to the result of the rapid elongation cutting test. understood. On the other hand, it was found that the insulated wires of Examples 16 to 18 each had an insulating coating that was not easily damaged, was excellent in flexibility, and was not easily peeled off from the copper wire. Further, from the results of the above-mentioned respective examples, the higher the proportion of DABAN, the higher the elastic modulus of the insulating coating and the less likely it is to damage the insulating coating. It was found that the lower the ratio, the better.

Comparing the results of Example 17 and Example 19 in which the ratio of DABAN is the same, both show almost the same characteristics, which indicates that PMDA as an acid component is obtained.
It was found that and s-BPDA give almost the same characteristics to the insulating coating. Similarly, when the results of Example 17 and Example 20 in which the proportion of DABAN is the same are compared, both show almost the same characteristics, which indicates that DAB
DDE and D as other diamine components used in combination with AN
It has been found that DM imparts almost the same characteristics to the insulating coating.

Furthermore, Example 1 in which the ratio of DABAN is the same
Comparing the results of Example 7 and Example 21, since Example 21 has a smaller floating amount of the insulating film in the rapid elongation cutting test than Example 17, other characteristics are maintained as they are by forming the underlayer. However, it was found that the adhesion of the coating can be further improved. Example 22 The amount of the diamine component charged during the preparation of the polyimide-based coating material was
DBRB = 0.1 mol, DABAN = 0.2 mol, DD
E = 0.2 mol, DBRB and D in all diamines
Except that the total proportion of ABAN was 50 mol%,
An insulated wire was produced in the same manner as in Example 2.

With respect to the insulated wire of the above example, the elastic modulus measurement, the flexibility test, the rapid cutting test and the piano wire damage load measurement were carried out. The above results are shown in Table 4 together with the results of Examples 2, 11, and 17 in which the proportion of the aromatic diamine compound in the diamine component is the same.

[0076]

[Table 4]

From the results in Table 4 above, when two kinds of aromatic diamine compounds are used in combination, the total ratio is the same as when the aromatic diamine compounds are used alone,
It has been found that it is possible to form an insulating film having almost the same characteristics.

[0078]

According to the insulated wire of the present invention, by introducing the structure of benzene, biphenyl or benzanilide into the structure of polyimide to improve the elastic modulus of the insulating coating, it is excellent in flexibility and moreover, An insulating coating that is not easily damaged can be formed. Therefore, the insulated wire of the present invention has excellent workability, and when it is used for winding a motor, for example, the insulating coating may be damaged in the winding process even if the winding amount to the core is increased more than ever before. Without
It is possible to meet the demand for smaller and lighter motors with better performance.

Claims (1)

[Claims] 1. An insulation having an insulating coating formed by applying and baking a polyimide coating composition containing a polyimide composed of an acid component containing at least tetracarboxylic dianhydride and a diamine component or polyamic acid as a precursor thereof. In the electric wire, the diamine component as a raw material has the following general formula (I): [In the above formula, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. n shows the number of 1-4. ], The following general formula (II): [In the above formula, R ² and R ³ 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 the following general formula (III): [In the above formula, R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. r and s are the same or different and each represents a number of 1 to 4. ]
At least one of the aromatic diamine compounds represented by
In the diamine component as a raw material containing a seed,
The total content ratio of these aromatic diamine compounds is 10 to
An insulated wire characterized by being 80 mol%.