JP2002056720A - Insulating covering material for winding wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulating covering material of winding wire, which has low dielectric property, high heat resistance and high moisture resistance. SOLUTION: This insulating covering material for the winding wire, contains polyimide resin having repeated units shown in formula (1). Here in the formula (1), R1 expresses a tetra-valent aromatic organic group; R2 expresses a divalent aromatic organic group; R1 and/or R2 express aromatic organic group which does not have C-H bond.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating coating material for a winding. More specifically, the present invention relates to an insulating coating material for a winding used in a motor, a transformer, a coil, and the like, which has excellent resistance to deterioration against application of a high-frequency voltage.

[0002]

2. Description of the Related Art A winding is an electric wire that is used by winding it into a coil inside an electric device. For example, a motor, a transformer (transformer), a high-frequency circuit, a coil for an electronic device, a generator, and the like are widely used. Used in various fields.

[0003] Windings are broadly classified into baked wires in which synthetic enamel is applied on a conductor and baked, and horizontal windings in which an insulator is wound around the conductor in a horizontal direction. Used in In particular, with recent advances in electronics, applications of windings to electric energy consuming devices have been remarkably expanded. However, the importance of heat-resistant enameled wires has been increasing as electric devices have become smaller and lighter. Conventionally, windings excellent in heat resistance, such as a polyimide wire and a polyamideimide wire, have been developed.

[0004] However, the materials used for coating conventional windings, when used under conditions where a high-frequency voltage is applied, causes the insulating coating to be easily degraded, thus shortening the life of electrical products and components. Problem. For example, in a television component, a high-frequency voltage is applied to a deflection yoke coil for scanning electrons of a cathode ray tube by electromagnetic deflection, a flyback transformer used for obtaining a high voltage power supply for an anode of the cathode ray tube, and the like. In an electromagnetic cooker (microwave oven), high-frequency voltage is applied to a work coil in order to cook food using high-frequency dielectric heating.

[0005] When such a high-frequency voltage is applied to the winding, the entire winding is heated, and the insulating coating is deteriorated by heat. Therefore, in consideration of such a problem, conventionally, measures such as coating the winding with a heat-resistant material or forming the winding into a stranded wire have been taken. However, measures to increase the heat resistance of the insulating material of the windings or to make the windings twisted lead to problems such as an increase in cost and a failure to satisfy the required characteristics of the coil, and the conventional winding. The coating material described above still has a problem that the deterioration resistance to application of a high-frequency voltage is not sufficient.

In recent years, in the field of television and CRT display devices, higher frequency voltages have been applied in order to perform high-precision display. In addition, electromagnetic cookers such as high frequency sewing machines and high frequency welders have been used. Similarly, equipment for heating by electromagnetic induction is increasing. Therefore, in order to increase the frequency of various devices, windings that are not only excellent in heat resistance but also resistant to deterioration against the application of high-frequency voltage are required, but conventional windings can sufficiently meet such required characteristics. Can not do it.

In order to overcome such a problem, a winding having excellent resistance to deterioration even when used under conditions where a high-frequency voltage is applied, has the following structural formula [I]:

[0008]

Embedded image

Wherein X represents a tetravalent organic group, and m is an integer of 1 to 4, and a polyimide containing a fluorine group or a paint containing a precursor of the polyimide is applied to the conductor. JP-A-6-44
No. 827.

However, the paint disclosed in the above publication has a problem that if the relative permittivity of the insulating film is still high at about 3.0, the entire winding is heated and the insulating film is deteriorated by heat. there were.

[0011]

SUMMARY OF THE INVENTION Therefore, an object of the present invention has been made in view of the above-mentioned circumstances, and has an excellent deterioration resistance even when used under conditions where a high-frequency voltage is applied. The present invention provides an insulating coating material for the winding shown.

[0012]

Means for Solving the Problems As a result of extensive studies to achieve the above objects, the present inventors have found that a polyimide resin having a specific structure has a relative dielectric constant of 2.8 to 2.3, which is a conventional insulating property. Paying attention to the fact that it is lower than the polyimide resin and other materials that have been used for the layer, the winding obtained by applying a paint containing this polyimide resin on the conductor under the conditions where high frequency voltage is applied It was also found that such an insulating coating material containing a polyimide resin can be used favorably for coating a winding.

The present inventors have also found that by introducing a fluorine atom into the molecule of this polyimide resin, the relative dielectric constant can be further reduced, that is, the deterioration resistance against application of a high-frequency voltage can be improved, Heat resistance has also been improved,
It has also been discovered that such a polyimide resin can be more suitably used as an insulating coating material for windings.

Based on the above findings, the present invention has been completed.

That is, the above-mentioned objects are as follows:
This is achieved by (8).

(1) The following formula (1):

[0017]

Embedded image

In the formula (1), R ¹ represents a tetravalent aromatic organic group; R ² represents a divalent aromatic organic group;
And R ¹ and / or R ² represent an aromatic organic group having no C—H bond. Insulating coating material for a winding comprising a polyimide resin having a repeating unit represented by

(2) In the formula (1), R ¹ and / or R ² represent an aromatic organic group having a halogen atom or a perhalogenoalkyl group at all residues. Wire insulation coating material.

(3) In the above formula (1), R ¹ and R ² represent C
(1) represents an aromatic organic group having no -H bond;
3. An insulating coating material for a winding according to claim 1.

(4) In the above formula (1), R ¹ and R ² each represent an aromatic organic group having a halogen atom or a perhalogenoalkyl group at all residues.
An insulating coating material for a winding according to any one of the above.

(5) In the above formula (1), R ¹ is the following formula:

[0023]

Embedded image

However, in the above formula, R ³ , R ⁴ and R ⁵ are
Each independently represents a halogen atom, a perhalogenoalkyl group, a perhalogenoalkoxyl group, a perhalogenoalkenoxy group, a perhalogenoalkynoxy group, a perhalogenophenoxy group, a perhalogenonaphthoxy group or a perhalogenoanthroxy group. And X is of the following formula:

[0025]

Embedded image

Wherein R ⁷ and R ⁸ each independently represent a halogen atom or a perfluoroalkyl group; R ⁹ represents a perfluoroalkylene group; and m is an integer of 1 to 10. The insulating coating material for a winding according to (1) or (3), wherein

(6) In the above formula (1), R ² is the following formula:

[0028]

Embedded image

In the above formula, R ¹⁰ , R ¹¹ and R
¹² is each independently a halogen atom, a perhalogenoalkyl group, a perhalogenoalkoxyl group, a perhalogenoalkenoxy group, a perhalogenoalkynoxy group, a perhalogenophenoxy group, a perhalogenonaphthoxy group or a perhalogenoanthratoxy group. And Y
Is the following formula:

[0030]

Embedded image

Wherein, in the above formula, R ¹³ and R ¹⁴ each independently represent a halogen atom or a perfluoroalkyl group; R ¹⁵ represents a perfluoroalkylene group; and n is an integer of 1 to 10. The insulating coating material of the winding according to (1), (3) or (5), wherein

(7) In the above formula (1), R ¹ is the following formula:

[0033]

Embedded image

The insulating coating material for a winding according to any one of the above (1) to (6),

(8) In the above formula (1), R ² is the following formula:

[0036]

Embedded image

The insulating coating material for a winding according to any one of the above (1) to (7),

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides the following formula (1):

[0039]

Embedded image

However, in the formula (1), R ¹ represents a tetravalent aromatic organic group; R ² represents a divalent aromatic organic group;
And R ¹ and / or R ² represent an aromatic organic group having no C—H bond. The present invention provides an insulating coating material for a winding comprising a polyimide resin having a repeating unit represented by the following formula:

Hereinafter, the present invention will be described in detail.

The insulating coating material of the winding of the present invention essentially contains a polyimide resin having a repeating unit represented by the above formula (1), and is preferably used for coating on a conductor. is there.

In the present invention, the polyimide resin constituting the insulating coating material of the winding is, as apparent from the description of the present invention, the following formula (1):

[0044]

Embedded image

Having a repeating unit represented by the formula:

In the above formula (1), R ¹ represents a tetravalent aromatic organic group, preferably a tetravalent aromatic organic group having no C—H bond, more preferably It represents a tetravalent aromatic organic group having a halogen atom or a perhalogenoalkyl group. Specific examples of R ^{1 that} can be used in the present invention include the following formula:

[0047]

Embedded image

And a tetravalent aromatic organic group represented by the formula: Of these, the following formula:

[0049]

Embedded image

A tetravalent aromatic organic group represented by the following formula is preferred as R ¹ . In the above formula, unless otherwise specified, the bonding positions of the substituents “X”, “R ³ ”, “R ⁴ ”, “R ⁵ ”, and “R ⁶ ” are not particularly limited, and the substituent “X” , "R ^3",
“R ⁴ ”, “R ⁵ ”, and “R ⁶ ” mean that they can be independently bonded to any of the residues within each benzene ring.

In the above formula, R^Three, R^Four, R^FiveAnd R⁶Is it
Each independently, such as fluorine, chlorine, bromine and iodine atoms
Halogen atom, preferably fluorine atom and chlorine atom,
Preferably a fluorine atom; or perhalogenoalkyl
Group, perhalogenoalkoxyl group, perhalogenoalk
Nonoxy group, perhalogenoalkynoxy group, perhalogeno
Phenoxy (-OC₆F_Five) Group, perhalogenonaphthoxy
(-OC_TenF₇) Group or perhalogeno anthractomy
Si (-OC₁₄F₉) Represents a group. At this time, perhalogeno
The alkyl group is not particularly limited, but has the number of carbon atoms.
But usually 1 to 5, preferably 1 to 3 perhalogeno
Alkyl groups, preferably perfluoroalkyl groups and
-Chloroalkyl group, particularly preferably perfluoroalkyl
Kill group (-C_pF_{2p + 1}At this time, p is an integer of 1 to 5
). Particularly preferably used in the present invention
Perfluoroalkyl groups include trifluoromethyl
Chill, pentafluoroethyl, heptafluoropropyl
, Heptafluoroisopropyl, perfluoro-n-
Butyl, perfluoro-sec-butyl, perfluoro
-Tert-butyl, perfluoropentyl, perful
Oroneopentyl, perfluoroisopentyl, etc.
Is mentioned. Of these, trifluoromethyl, pe
N-fluoroethyl, heptafluoropropyl and hept
Tafluoroisopropyl is a perfluoroalkyl group
Preferred. Also, as a perhalogenoalkoxyl group
Is also not particularly limited, but usually has 6 to 1 carbon atoms.
2, preferably 6 to 9 perhalogenoalkoxyl
Groups, preferably perfluoroalkoxyl groups and parks
Loroalkoxyl group, particularly preferably perfluoroalkyl
Coxyl group (-OC_qF_{2q + 1}At this time, q is 6 to 12.
Which is an integer). Particularly preferred in the present invention
Commonly used perfluoroalkoxyl groups include-
OC₆F₁₃, -OC₇F_Fifteen, -OC₈F₁₇, -OC₉F₁₉,
-OC_TenF_{twenty one}, -OC ₁₁F_{twenty three}, And -OC₁₂F_{twenty five}Indicated by
Perfluoroalkoxyl group. This
Of these, -OC₆F₁₃, -OC₇F_Fifteen, -OC₈F₁₇
And -OC₉F₁₉Is a perfluoroalkoxyl group
preferable. Furthermore, as a perhalogenoalkenoxy group
Is also not particularly limited, but usually has 6 to 1 carbon atoms.
2, preferably 6 to 9 perhalogenoalkenoxy
Groups, preferably perfluoroalkenoxy groups and parks
Loloalkenoxy group, particularly preferably perfluoroal
Kenoxy group (-OC_qF_2q-1Q is an integer of 6-12
). Particularly preferably used in the present invention
The perfluoroalkenoxy group is -OC₆F_1
1, -OC₇F₁₃, -OC₈F_Fifteen, -OC₉F₁₇, -OC_Ten
F₁₉, -OC₁₁F_{twenty one}And -OC₁₂F_{twenty three}Etc.
-Fluoroalkenoxy group and the like. these
Of which, -OC₆F₁₁, -OC₇F₁₃, -OC₈F_FifteenAnd-
OC₉F₁₇Is preferred as a perfluoroalkenoxy group
No. Furthermore, as a perhalogenoalkynoxy group
Is also not particularly limited, but usually has 6 to 1 carbon atoms.
2, preferably 6 to 9 perhalogenoalkynoxy
Groups, preferably perfluoroalkynoxy groups and parks
Loloalkynoxy group, particularly preferably perfluoroalky
Quinoxy group (-OC_qF_2q-3Q is an integer of 6-12
). Particularly preferably used in the present invention
Perfluoroalkynoxy groups include -OC
₆F₉, -OC₇F₁₁, -OC₈F₁₃, -OC₉F_Fifteen, -O
C_TenF₁₇, -OC₁₁F₁₉, And -OC₁₂F_{twenty one}Indicated by
And perfluoroalkynoxy groups. these
Of which, -OC₆F₉, -OC₇F₁₁, -OC₈F₁₃And-
OC₉F_FifteenIs preferred as a perfluoroalkynoxy group
No.

At this time, the perhalogenoalkyl group, perhalogenoalkoxyl group, perhalogenoalkenoxy group and perhalogenoalkynoxy group according to the present invention are, needless to say, the corresponding perfluoroalkyl groups described above.
The perfluoroalkoxy group, perfluoroalkenoxy group, and the above-mentioned perfluoroalkane except that the monovalent element bonded to the carbon of the perfluoroalkynoxy group is not limited to fluorine and other halogen atoms may be used. It is the same as that enumerated for the alkyl group and the like, and the monovalent halogen atom bonded to one carbon may be the same or different. In the present invention, when a plurality of substituents “R ³ ”, “R ⁴ ”, “R ⁵ ” and “R ⁶ ” are present in a single aromatic ring such as a benzene ring, these R ³ , R ⁴ , R ⁵ and R ⁶ may be the same or different.

Further, in the above formula, X is the following formula:

[0054]

Embedded image

Wherein R ⁷ and R ⁸
Each independently represents a halogen atom such as a fluorine, chlorine, bromine and iodine atom, preferably a fluorine atom and a chlorine atom, particularly preferably a fluorine atom; or a perfluoroalkyl group. At this time, the perfluoroalkyl group is not particularly limited, but usually has 1 carbon atom.
To 5, preferably 1 to 3 perfluoroalkyl groups. Specifically, as the perfluoroalkyl group, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl,
Examples include perfluoro-n-butyl, perfluoro-sec-butyl, perfluoro-tert-butyl, perfluoropentyl, perfluoroneopentyl, and perfluoroisopentyl. Of these, trifluoromethyl, pentafluoroethyl, heptafluoropropyl and heptafluoroisopropyl are preferred as perfluoroalkyl groups. R ⁹ is a perfluoroalkylene group, usually having 1 to 4 carbon atoms.
6, preferably 1 to 3 perfluoroalkylene groups,
For example, difluoromethylene, tetrafluoroethylene and hexafluoropentylene. Furthermore, m
Has the formula:-(OR ⁹ )-,-(R ⁹ O)-, or-
(OR ⁹ O) — represents the number of each repeating unit when represented by —, and is 1 to 10, preferably 1 to 6, more preferably 1
-3.

Among them, R ¹ is represented by the following formula:

[0057]

Embedded image

It is preferred to represent, in particular, the following formula:

[0059]

Embedded image

It is preferred to represent

In the above formula (1), R ² is 2
A divalent aromatic organic group having no C—H bond, more preferably a divalent aromatic organic group having a halogen atom or a perhalogenoalkyl group in all residues Represents a group. At this time, when R ² represents a divalent aromatic organic group having a halogen atom or a perhalogenoalkyl group at all residues, specific examples of R ² include the following formulas:

[0062]

Embedded image

A divalent aromatic organic group represented by Of these, the following formula:

[0064]

Embedded image

A divalent aromatic organic group represented by the following formula is preferred as R ² . In the above formula, unless otherwise specified, the bonding positions of the substituents “Y”, “R ¹⁰ ”, “R ¹¹ ”, and “R ¹² ” are not particularly limited, and the substituents “Y”, “R ¹⁰ ” ,
It means that “R ¹¹ ” and “R ¹² ” can be mutually independently bonded to any of the residues within each benzene ring.

In the above formula, R^Ten, R¹¹And R¹²Each
Independently of fluorine, chlorine, bromine and iodine atoms.
A halogen atom, preferably a fluorine atom and a chlorine atom,
Preferably a fluorine atom; or perhalogenoalkyl
Group, perhalogenoalkoxyl group, perhalogenoalk
Nonoxy group, perhalogenoalkynoxy group, perhalogeno
Phenoxy (-OC₆F_Five) Group, perhalogenonaphthoxy
(-OC_TenF₇) Group or perhalogeno anthractomy
Si (-OC₁₄F₉) Represents a group. At this time, perhalogeno
The alkyl group is not particularly limited, but has the number of carbon atoms.
But usually 1 to 5, preferably 1 to 3 perhalogeno
Alkyl groups, preferably perfluoroalkyl groups and
-Chloroalkyl group, particularly preferably perfluoroalkyl
Kill group (-C_pF_{2p + 1}At this time, p is an integer of 1 to 5
). Particularly preferably used in the present invention
Perfluoroalkyl groups include trifluoromethyl
Chill, pentafluoroethyl, heptafluoropropyl
, Heptafluoroisopropyl, perfluoro-n-
Butyl, perfluoro-sec-butyl, perfluoro
-Tert-butyl, perfluoropentyl, perful
Oroneopentyl, perfluoroisopentyl, etc.
Is mentioned. Of these, trifluoromethyl, pe
N-fluoroethyl, heptafluoropropyl and hept
Tafluoroisopropyl is a perfluoroalkyl group
Preferred. Also, as a perhalogenoalkoxyl group
Is also not particularly limited, but usually has 6 to 1 carbon atoms.
2, preferably 6 to 9 perhalogenoalkoxyl
Groups, preferably perfluoroalkoxyl groups and parks
Loroalkoxyl group, particularly preferably perfluoroalkyl
Coxyl group (-OC_qF_{2q + 1}At this time, q is 6 to 12.
Which is an integer). Particularly preferred in the present invention
Commonly used perfluoroalkoxyl groups include-
OC₆F₁₃, -OC₇F_Fifteen, -OC₈F₁₇, -OC₉F₁₉,
-OC_TenF_{twenty one}, -OC ₁₁F_{twenty three}, And -OC₁₂F_{twenty five}Indicated by
Perfluoroalkoxyl group. This
Of these, -OC₆F₁₃, -OC₇F_Fifteen, -OC₈F₁₇
And -OC₉F₁₉Is a perfluoroalkoxyl group
preferable. Furthermore, as a perhalogenoalkenoxy group
Is also not particularly limited, but usually has 6 to 1 carbon atoms.
2, preferably 6 to 9 perhalogenoalkenoxy
Groups, preferably perfluoroalkenoxy groups and parks
Loloalkenoxy group, particularly preferably perfluoroal
Kenoxy group (-OC_qF_2q-1Q is an integer of 6-12
). Particularly preferably used in the present invention
The perfluoroalkenoxy group is -OC₆F_1
1, -OC₇F₁₃, -OC₈F_Fifteen, -OC₉F₁₇, -OC_Ten
F₁₉, -OC₁₁F_{twenty one}And -OC₁₂F_{twenty three}Etc.
-Fluoroalkenoxy group and the like. these
Of which, -OC₆F₁₁, -OC₇F₁₃, -OC₈F_FifteenAnd-
OC₉F₁₇Is preferred as a perfluoroalkenoxy group
No. Furthermore, as a perhalogenoalkynoxy group
Is also not particularly limited, but usually has 6 to 1 carbon atoms.
2, preferably 6 to 9 perhalogenoalkynoxy
Groups, preferably perfluoroalkynoxy groups and parks
Loloalkynoxy group, particularly preferably perfluoroalky
Quinoxy group (-OC_qF_2q-3Q is an integer of 6-12
). Particularly preferably used in the present invention
Perfluoroalkynoxy groups include -OC
₆F₉, -OC₇F₁₁, -OC₈F₁₃, -OC₉F_Fifteen, -O
C_TenF₁₇, -OC₁₁F₁₉, And -OC₁₂F_{twenty one}Indicated by
And perfluoroalkynoxy groups. these
Of which, -OC₆F₉, -OC₇F₁₁, -OC₈F₁₃And-
OC₉F_FifteenIs preferred as a perfluoroalkynoxy group
No.

At this time, the perhalogenoalkyl according to the present invention
Group, perhalogenoalkoxyl group, perhalogenoal
Kenoxy and perhalogenoalkynoxy groups are
But also the corresponding perfluoroalkyl group described above,
Perfluoroalkoxyl group, perfluoroalkenoki
Binds to carbons of di- and perfluoroalkynoxy groups
The monovalent element is not limited to fluorine, and other halogen atoms may be used.
Except that it may be used, the above perfluoroalkyl group
Etc. are the same as those listed for
Even if the monovalent halogen atoms bonded to the carbon
Alternatively, they may be different. In addition, the present invention
And the substituent "R^Ten”,“ R¹¹"And" R¹²Is one
When two or more exist in an aromatic ring such as a benzene ring,
Those R ^Ten, R¹¹And R¹²May be the same
Or different.

Further, in the above formula, Y is the following formula:

[0069]

Embedded image

Wherein R ¹³ and R ^13
14 each independently represents a halogen atom such as a fluorine, chlorine, bromine and iodine atom, preferably a fluorine atom and a chlorine atom, particularly preferably a fluorine atom; or a perfluoroalkyl group. At this time, the perfluoroalkyl group is not particularly limited, and examples thereof include a perfluoroalkyl group having usually 1 to 5, preferably 1 to 3, carbon atoms. Specifically, examples of the perfluoroalkyl group include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl, perfluoro-n-butyl, and perfluoro-se.
Examples include c-butyl, perfluoro-tert-butyl, perfluoropentyl, perfluoroneopentyl, and perfluoroisopentyl. Of these, trifluoromethyl, pentafluoroethyl, heptafluoropropyl and heptafluoroisopropyl are preferred as perfluoroalkyl groups. Also, R
¹⁵ represents a perfluoroalkylene group, usually having 1 to 6, preferably 1 to 3, carbon atoms, such as difluoromethylene, tetrafluoroethylene and hexafluoropentylene. Further, n is such that Y is represented by the formula:-(OR ¹⁵ )-,-(R ¹⁵
O) -, or - (OR ¹⁵ O) - represents the number of repeating units of time represented by 1 to 10, preferably 1 to 6,
More preferably, it is an integer of 1 to 3.

Among them, R ² is represented by the following formula:

[0072]

Embedded image

It is preferred to represent, in particular, the following formula:

[0074]

Embedded image

It is preferred to represent

In the present invention, in the formula (1), at least one of R ¹ and R ² is an aromatic organic group having no C—H bond, preferably a halogen atom or perhalogeno group at all residues. It is essential to represent an aromatic organic group having an alkyl group. More preferably, R
^{Both 1} and R ² represent an aromatic organic group having no C—H bond, most preferably an aromatic organic group having a halogen atom or a perhalogenoalkyl group at all residues. It is as follows.

In the present invention, it is essential that the polyimide resin has a repeating unit represented by the formula (1), but the polyimide resin may have a repeating unit other than the repeating unit represented by the formula (1). Good. Other repeating units that can be used at this time include amide acids, aminocarboxylic acids, and aminocarboxylic acid amides into which a crosslinkable reactive group has been introduced for the purpose of facilitating the coating of the polyimide film. Further, the polyimide resin may be composed of the same repeating unit among these repeating units or may be composed of different repeating units,
In the latter case, the repeating unit may be block-shaped or random. Further, when the polyimide resin contains other repeating units described above,
The content of the repeating unit of the formula (1) with respect to all the repeating units constituting the polyimide resin is not particularly limited, but is usually 30 to 100%, preferably 50 to 10%.
0%.

In the present invention, the polyimide resin having a repeating unit of the formula (1) can be produced by a method similar to the publicly known method, and the production method is not particularly limited. 580 and JP-A-2-208,324. One example is briefly described below. First, a tetracarboxylic acid or a derivative thereof is reacted with a diamine in approximately equimolar amounts to obtain a polyamic acid, and the thus obtained polyamic acid is chemically or heated to be polyimide to obtain a compound of the formula (1) A polyimide resin having the repeating unit of (1) is obtained. As the tetracarboxylic acid or its derivative used in the above method,
Any alkyl group in the molecule, and any monovalent element bonded to carbon such as a phenyl ring may be a halogen atom, preferably fluorine, or a perhalogenoalkyl group, preferably a perfluoroalkyl group. Good, for example, 1,4-difluoropyromellitic acid, 1-
Trifluoromethyl-4-fluoropyromellitic acid,
1,4-di (trifluoromethyl) pyromellitic acid,
1,4-di (pentafluoroethyl) pyromellitic acid,
Hexafluoro-3,3 ', 4,4'-biphenyltetracarboxylic acid, hexafluoro-3,3', 4,4'-
Benzophenonetetracarboxylic acid, 2,2-bis (3,
4-dicarboxytrifluorophenyl) hexafluoropropane, 1,3-bis (3,4-dicarboxytrifluorophenyl) hexafluoropropane, 1,4-
Bis (3,4-dicarboxytrifluorophenoxy)
Tetracarboxylic acids such as tetrafluorobenzene, 1,4-bis (3,4-dicarboxytrifluorophenoxy) tetrachlorobenzene, and hexafluoro-3,3 ′, 4,4′-oxybisphthalic acid; and tetracarboxylic acids Examples of the acid derivatives include acid dianhydrides, acid halides, monoesters and diesters of these tetracarboxylic acids. Among these, 1,4-di (trifluoromethyl) pyromellitic dianhydride, which is a fluorinated dianhydride having a fluoroalkyl group introduced into the benzene ring of pyromellitic dianhydride, and 1,4- As a method for producing di (pentafluoroethyl) pyromellitic dianhydride or the like, a method described in JP-A-2-15,084 can be used.

Examples of the diamine used in the above method include all monovalent elements bonded to carbon such as an alkyl group and a phenyl group are halogen atoms, preferably fluorine,
Alternatively, any perhalogenoalkyl group, preferably a perfluoroalkyl group, may be used. For example, 3,4,5,6-tetrafluoro-1,2
-Phenylenediamine, 3,4,5,6-tetrachloro-1,2-phenylenediamine, 2,4,5,6-tetrafluoro-1,3-phenylenediamine, 2,4
5,6-tetrachloro-1,3-phenylenediamine,
2,3,5,6-tetrafluoro-1,4-phenylenediamine, 2,3,5,6-tetrachloro-1,4-phenylenediamine, 2,4,6-tetrafluoro-5
Chloro-1,3-phenylenediamine, 4,4′-diaminooctafluorobiphenyl, bis (2,3,5,6
-Tetrafluoro-4-aminophenyl) ether, bis (2,3,5,6-tetrafluoro-4-aminophenyl) sulfone, hexafluoro-2,2 '-(bistrifluoromethyl) -4,4'- Diaminobiphenyl,
1,4-bis (3-aminotetrafluorophenoxy)
Examples include tetrafluorobenzene, 1,4-bis (3-aminotetrafluorophenoxy) tetrachlorobenzene, and 2,2-bis (3-aminotetrafluorophenyl) hexafluoropropane.

When the polyimide is soluble, the corresponding diisocyanate can be used in place of the diamine.

In the above method, the reaction between the tetracarboxylic acid or a derivative thereof and the diamine is carried out in the same manner as in a known method for producing a polyamic acid, whether in a solvent or without a solvent. The reaction is preferably performed in a solvent, particularly preferably in a polar organic solvent as exemplified below to obtain a polyamic acid solution. The solvent used at this time is not particularly limited, but for example, N-methyl-2-pyrrolidone, N, N
Polar organic solvents such as -dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, methylcellosolve, benzonitrile, acetone and acetonitrile; and low-polarity organic solvents such as tetrahydrofuran and chloroform. In the above reaction, in the present invention, the tetracarboxylic acid such as tetracarboxylic dianhydride or the derivative thereof and the diamine may be used as a single compound or two or more kinds of diamine and / or tetracarboxylic acid, respectively. It may be used in the form of a mixture of acid dianhydrides. In the latter case, it is preferred that the sum of the moles of the plural or single diamine used is equal to or approximately equal to the sum of the moles of the plural or single tetracarboxylic dianhydride. Also, when producing perfluorinated polyamic acid,
By using a non-perfluorinated acid anhydride component and a diamine component, a partially non-fluorinated polyamic acid is produced.In this case, if the ratio is not excessively large, a purification step is particularly required. Without accompanying, it may be directly supplied to the next step, imidation step, in a form containing a partially fluorinated polyamic acid.

The reaction conditions of the tetracarboxylic acid or the derivative thereof with the diamine are not particularly limited as long as the reaction proceeds efficiently. For example, the reaction between the tetracarboxylic acid or the derivative thereof and the diamine is not limited. Stirring of the contained solution may or may not be performed if the reaction system is uniform, but it is desirable to perform stirring if the reaction system is non-uniform. The stirring speed at the time of stirring is not particularly limited as long as these reactions proceed promptly, but it is desirable that the stirring liquid does not contain bubbles. The reaction temperature is usually -20 to 200C, preferably 0 to 100C.
The reaction time is generally 1 to 72 hours, preferably 2 to 48 hours. In addition, the reaction may be performed under any of the pressures, normal pressures and reduced pressures, but is preferably performed under normal pressures.

Next, as a method for producing a desired polyimide from the polyamic acid obtained by the above reaction, a known method for preparing a polyimide can be used. For example, the polyamic acid is converted into a polyimide by a chemical treatment or a heat treatment. Method. Among them, examples of the former chemical treatment method of polyamic acid include a treatment method using an imidizing agent (for example, acetic anhydride and pyridine). In addition, as an example of the latter heat treatment method of polyamic acid, for example, polyamic acid is preferably added under an inert gas atmosphere such as argon gas, helium gas, and nitrogen gas, usually at 20 to 500 ° C., preferably 50 ° C. ~
A method of heating at a reaction temperature of 400 ° C. for usually 1 to 48 hours, preferably 2 to 24 hours is mentioned.

More specifically, after the polyamic acid solution obtained by the above reaction is applied on a conductor by casting or the like, for example, by adding an imidizing agent such as acetic anhydride or pyridine or at 20 to 500 ° C., preferably 50
The polyamide acid is imidized by heating at ４００400 ° C. for 1 to 48 hours, preferably 2 to 24 hours, whereby a winding insulated with a polyimide resin is obtained. At this time, the concentration of the polyamic acid in the solution is
The concentration is not particularly limited as long as it is easy to cast on a conductor and imidization can be sufficiently achieved, but it is usually 10 to 60% by mass, preferably 20 to 50% by mass based on the weight of the whole solution. Further, the viscosity of the polyimide resin solution after the reaction gradually increases due to the reaction between the tetracarboxylic acid or its derivative and the diamine, and the viscosity of the polyamic acid solution at this time is 0.5 to 100 at 25 ° C.
It is preferably in the range of about Pa · s, more preferably about 10 to 50 Pa · s.

Alternatively, the polyamic acid solution can be prepared by adding an imidizing agent such as acetic anhydride or pyridine or at a high temperature (for example, 20 to 500 ° C., preferably 50 to 400 ° C.).
~ 48 hours, preferably 2 to 24 hours, imidation by heating to obtain a polyimide solution, after which
This polyimide solution may be applied on a conductor by casting or the like, and then dried to obtain a winding insulated with a polyimide resin. At this time, the concentration of the polyimide in the solution is not particularly limited as long as the concentration is such that it can be easily cast on the conductor.However, in consideration of the ease of application by casting or the like and the mechanical strength of the polyimide as an insulating film, the total concentration is not limited. It is usually from 10 to 60% by mass, preferably from 20 to 50% by mass, based on the weight of the solution.

Alternatively, a tetracarboxylic acid or a derivative thereof and a diamine are vapor-deposited on a conductor using a vacuum vapor-deposition apparatus to obtain a polyamic acid.
Heat treatment may be performed at 500 ° C., preferably 50 to 400 ° C., for 1 to 48 hours, preferably 2 to 24 hours to imidize to obtain a winding insulated with a polyimide resin. Although the above method has the disadvantage of requiring a large-scale reaction facility, it is preferable in that a high-purity polyimide film with very few impurities is obtained because no solvent is required.

In the present invention, the polyamic acid solution contains 2
May be used as a mixture of more than one kind of polyamic acid,
Also, as long as desired properties (for example, heat resistance and low dielectric properties) are acceptable, as a mixture with another polyamic acid solution, a polyimide solution, or a resin solution other than polyimide as described in detail below. May be used.

The conductor used in the present invention is not particularly limited, and any known conductor may be used. For example, high-purity to ultra-high-purity copper wire, gold wire, light wire, etc. Metals such as hard aluminum wires twisted with galvanized steel wires, and conductive polymers such as conjugated polymers such as polyacetylene, polypyrrole, and polyparaphenylene are exemplified. Also, the diameter of the conductor is not particularly limited, and can be appropriately selected depending on the use.

The polyimide resin thus manufactured has a sufficiently low dielectric constant of 2.8 to 2.3, for example, a polyimide having no fluorine atom has a dielectric constant of 3. Considering that it is about 5, by using the polyimide resin according to the present invention, it is possible to give a significantly lower relative dielectric constant than an ordinary insulating coating of a winding. Therefore, by using the polyimide resin according to the present invention for the insulating coating material of the winding, a high-frequency voltage is applied to the winding, and the entire winding is heated. Since the dielectric constant of the insulating film made of the polyimide resin according to the present invention is sufficiently low, the calorific value is significantly suppressed, and the deterioration rate of the insulating film is slowed down. Because it is harder to deteriorate than the wire,
As a result, it is possible to prolong the life of the winding for high-frequency voltages. Further, the polyimide resin used in the present invention is preferable because it has excellent moisture resistance and weather resistance and also has sufficient flexibility.

The polyimide resin thus produced has both excellent insulating properties and mechanical strength. However, when the desired properties such as the above-mentioned properties and solvent resistance are not sufficient, And other components such as amines and diamines having a polymerizable unsaturated carbon bond, dicarboxylic acid, tricarboxylic acid, tetracarboxylic acid, maleic acid, nadic acid, 3-ethylphthalic acid, anhydrides thereof, ethynylaniline, cyano By adding aniline or the like, the polymerizable component is modified or crosslinked, or an aromatic diamine having a phenolic hydroxyl group or a carboxylic acid, for example, diaminophenol, 3,3′-dihydroxybenzidine,
2,2-bis (3-amino-4-hydroxyphenyl)
Hexafluoropropane, diaminobenzoic acid, modified and cross-linked polyimide resin with carboxybenzidine, etc.,
Various properties such as solvent resistance may be improved.

In the present invention, the insulating coating material of the winding is
Although it is essential to include a polyimide resin having a specific structure as described above, in addition to this polyimide resin,
Other components may be further contained within a range that does not adversely affect the desired low relative dielectric constant, deterioration resistance, heat resistance, and the like and does not depart from the scope of the present invention. As further components, for example, polyamide, polyamide imide, epoxy resin, phenol resin, melamine resin, urea resin, diallyl phthalate resin, unsaturated polyester resin, urethane resin, addition-type polyimide resin, silicone resin, polyparavinylphenol resin, Polyphenylene sulfide, polyether, polyether ether ketone, polypropylene and polyazomethine; polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE),
Fluororesins such as tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA) and polychlorotrifluoroethylene (PCTFE); calcium carbonate, silica, alumina, titania, aluminum hydroxide, aluminum silicate, zirconium silicate, zircon , Glass, talc, mica, graphite, aluminum, copper, iron and other powders and short-fiber inorganic fillers; release agents such as fatty acids and waxes; epoxy silanes, vinyl silanes, borane compounds and alkyl titanate compounds Coupling agents; flame retardants such as antimony and phosphorus compounds and halogen-containing compounds; and various additives such as dispersants and solvents. The content of the additional component when the additional component is included in addition to the polyimide resin is 1 to 49% by mass based on the whole raw materials.

The method of coating the conductor with the coating agent of the present invention is not particularly limited, and a known method can be used. Specifically, casting (casting method), spin coating (rotation coating method), roll coating, spray coating, bar coating, flexographic printing,
And methods such as dip coating.
Of these methods, dip coating is preferably used in view of easy coating. In the case where other components as described above are contained in addition to the polyimide resin, for example, methods such as casting, spin coating, roll coating, spray coating, bar coating, flexographic printing, and dip coating are exemplified. The thickness of the insulating coating made of the insulating coating material of the present invention can be appropriately selected in accordance with the desired properties and applications, the material thereof, and the like.

[0093]

The present invention will be described more specifically below with reference to examples.

Example 1 A solution prepared by dissolving a fluorine-containing polyimide represented by the following formula in dimethylacetamide at a concentration of 40% by mass was processed into a film by a solution casting method, and baked at 350 ° C. for 5 hours to obtain a film having a thickness. A 10 μm film was obtained. The relative permittivity of the obtained film was measured using an impedance analyzer (HP4, HP4).
294A) at a frequency of 1 MHz, the relative dielectric constant was 2.6.

[0095]

Embedded image

Comparative Example 1 A commercially available polyimide varnish (manufactured by DuPont) was processed into a film by a solution casting method and baked at 350 ° C. for 1 hour to obtain a film having a thickness of 25 μm. The relative permittivity of the obtained film was measured in the same manner as in the example, and was 3.5.

(Result) From Example 1 and Comparative Example 1, the insulating layer of the multilayer wiring board of the present invention has a significantly lower dielectric constant than the insulating layer made of polyimide which has been conventionally used for the insulating layer. It was shown to have.

[0098]

As described above, the insulating coating material of the winding according to the present invention is characterized by containing a polyimide resin having a repeating unit represented by the above formula (1). Therefore, the polyimide resin according to the present invention has a sufficiently low relative dielectric constant, and its deterioration resistance is greatly improved even when a higher high-frequency voltage is applied. Useful for In addition to the advantages described above, the polyimide resin according to the present invention also has high moisture resistance and high weather resistance. Therefore, an insulating coating material for a winding including the polyimide resin also has the above-described characteristics, and thus is preferable.

When a polyimide resin having a fluorine atom introduced into the molecule is used, the insulating coating material of the winding can further reduce the relative dielectric constant and improve heat resistance and solubility. You.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 5/06 H01F 5/06 Q 27/32 27/32 Z (72) Inventor Yasunori Okumura Tsukuba, Ibaraki 1-25-25 Kannondai F-term (reference) in Nippon Shokubai Co., Ltd. 4J038 DJ021 DJ031 GA12 KA06 MA09 NA14 NA21 PA19 PB09 PC02 4J043 PA02 PC136 PC146 PC156 QB15 QB31 RA35 SA06 SA47 SA52 SA54 SA55 SB01 TA14 TA22 TA42 TA43 TA47 TA47 TB01 UA121 UA122 UA131 UA132 UA141 UA142 UB121 UB122 UB131 UB132 UB151 UB152 UB161 UB162 UB171 UB172 UB301 UB302 VA011 VA012 VA021 VA022 VA031 VA032 VA041 VA042 VA051 VA052 VA061 VA061 VA071 ZA072 VA071 VA071 VA071 VA071 VA071 VA071 VA071 VA071 VA071 VA071 VA071 VA071 AB10 AB24 AB26 BA09 CA21 CA38 5G309 MA02

Claims (6)

[Claims] 1. The following formula (1): Wherein, in the formula (1), R ¹ represents a tetravalent aromatic organic group; R ² represents a divalent aromatic organic group; and R ¹ and / or R ² have a CH bond. An insulating coating material for a winding, comprising a polyimide resin having a repeating unit represented by the following formula: 2. The winding according to claim 1, wherein in the formula (1), R ¹ and / or R ² represent an aromatic organic group having a halogen atom or a perhalogenoalkyl group at all residues. Insulation coating material. 3. The insulating coating material for a winding according to claim 1, wherein in the formula (1), R ¹ and R ² represent an aromatic organic group having no C—H bond. 4. The compound according to claim 1, wherein in the formula (1), R ¹ and R ² represent an aromatic organic group having a halogen atom or a perhalogenoalkyl group at all residues.
Item 7. Insulation coating material for windings according to item 6. 5. In the formula (1), R ¹ is a compound represented by the following formula: However, in the above formula, R ³ , R ⁴ and R ⁵ are each independently a halogen atom, a perhalogenoalkyl group, a perhalogenoalkoxyl group, a perhalogenoalkenoxy group,
X represents a perhalogenoalkynoxy group, a perhalogenophenoxy group, a perhalogenonaphthoxy group or a perhalogenoanthratoxy group; and X represents the following formula: However, in the above formula, R ⁷ and R ⁸ are each independently
Represents a halogen atom or a perfluoroalkyl group;
R ⁹ is perfluoroalkylene group to represent; and m represents an integer of 1 to 10, insulating coating material of windings of claim 1 or 3. 6. In the formula (1), R ² is a compound represented by the following formula: However, in the above formula, R ¹⁰ , R ¹¹ and R ¹² are each independently a halogen atom, a perhalogenoalkyl group, a perhalogenoalkoxyl group, a perhalogenoalkenoxy group, a perhalogenoalkynoxy group, a perhalogeno group. Represents a phenoxy group, a perhalogenonaphthoxy group or a perhalogenoanthratoxy group; and Y is a compound represented by the following formula: Wherein, in the above formula, R ¹³ and R ¹⁴ each independently represent a halogen atom or a perfluoroalkyl group; R ¹⁵ represents a perfluoroalkylene group; and n is an integer of 1 to 10. The insulation coating material of a winding according to claim 1, 3 or 5, wherein: