JPH0831285B2 - Insulated wire that can be soldered - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-resistant insulated wire that can be subjected to a solder stripping treatment, and more specifically, a novel solder stripping property, a softening temperature, a heat resistance and a workability which are excellent. Polyester imide resin /
The present invention relates to a heat resistant insulated electric wire coated with a linear polyester amide imide resin.

(Prior art and its problems) In recent years, there has been a remarkable reduction in size and weight of electric devices such as motors and transformers. This plays a part in miniaturization and weight reduction not only of home appliances but also of automobiles and aircraft.

Further, it is strongly desired to improve the reliability of electric equipment, and a material having excellent heat resistance is required for an insulated wire used for electric equipment such as a motor and a transformer.

Also, in order to reduce the size and weight of the equipment, it is necessary to make the wires thinner, and the thinner insulated wires are subjected to a higher load than in the past, so naturally higher performance is required for the insulated wires. It came to be.

As a result, the insulating material has improved heat resistance, and is a thermally stable material, and is a class H (180 ° C) tris- (2-hydroxyethyl) isocyanurate (hereinafter abbreviated as THEIC) -containing polyesterimide insulated wire, H Type (180 ° C) THEIC-containing polyesteramide imide insulated wire, type K (200 ° C)
Of aromatic polyamide-imide insulated wire and M type (220
℃) polyimide insulated wire was developed.

Since these insulated wires are used in a harsh environment, chemical resistance, solvent resistance, hydrolysis resistance and alkali resistance are required. The insulated wire described above is generally excellent in chemical resistance.

In summary, insulated wires are desired to have improved heat resistance, chemical resistance, and thinning, and insulating paint manufacturers have responded to these demands.

In addition to improving the heat resistance of insulated wires, electrical equipment manufacturers are working to streamline processes by promoting labor saving, production lines and thin lines for the purpose of cost reduction.
We are demanding higher performance than ever before. As an example of labor saving and line-up, there is line-up of the terminal stripping process of the insulated wire.

Currently, this terminal stripping treatment is (1) mechanical stripping, (2)
There are various methods such as thermal decomposition stripping, (3) chemical stripping, (4) solder stripping, etc., but considering the working time, making the conductors of fine wires intact and continuous processing, etc., the solder stripping method of (4) above Is said to be the most preferable.

For this reason, it is possible to perform solder peeling treatment from electrical equipment manufacturers, so-called solder peeling is possible, and heat resistance is F
There is a strong demand for insulated wires of type (155 ° C) to type H (180 ° C).

To this end, multi-structured lines consisting of a solder-releasable polyesterimide / linear polyesteramideimide coating have been developed.

It is a known fact that an insulating film that can be subjected to a solder peeling treatment can be formed on a conductor. In this field, the expression that solder peeling treatment is possible means that when the insulated wire is immersed in a heated solder bath, the insulating film is decomposed and removed at the immersed portion, and at this point, the conductor is soldered. Therefore, the soldering is easy, not the direct soldering.

In addition, when soldering a number of insulated wires, such as a litz wire used in the deflection yoke of high-definition television, such as a litz wire, as well as several insulated wires, There has been an increase in the number of terminal treatments in which the insulation coating is peeled off and soldered all at once by immersing the as-coated wire in a solder bath.

For this purpose, the insulating coating must be removed as soon as possible, i.e. instantaneously, following immersion in the solder bath.
It goes without saying that the shorter the immersion in the solder bath, the better. An alloy of lead and tin is used as a solder bath for this purpose.

Decoating and soldering are carried out in essentially the same manner as in the connection of printed circuits to conductors.

On the other hand, as an insulated wire having solderability, a polyurethane insulated wire containing a compound having at least two hydroxyl groups and a diisocyanate or a higher functional blocked isocyanate is used.

Polyurethane insulated wires with a main chain containing thermally depolymerizable groups such as urethane bonds and urea bonds, which have low binding energy, can be directly soldered in the low temperature range of 320 ℃ to the high temperature range of 400 ℃.

However, the heat resistance of the polyurethane insulated wire was at most E class (120 ° C). On the contrary,
Recently, a polyesterimide / polyisocyanate-coated electric wire has been developed that has a heat resistance of 130 to 155 ° C and a soldering temperature of 370 ° C.

When removing the insulated wire from the solder, the higher the heat resistance, the higher the decomposition temperature of the film in the molten solder bath must be, and in order to completely decompose the film and not leave the carbonized film on the conductor, It has become necessary to prolong the immersion treatment time in the molten solder bath.

As a processing condition for solder peeling in a certain line, a high temperature short time immersion method is adopted, and it is performed at 520 ° C. and 1 to 2 seconds. However, when the temperature of the molten solder bath exceeds 400 ° C., the oxidative deterioration of the solder bath further progresses, and the rate at which copper dissolves in the solder increases, which causes a problem of thinning of the insulated wire.

Therefore, the temperature of the solder bath is at least around 450 ° C,
The immersion treatment time is preferably within 10 seconds.

However, although the heat resistance of the above-mentioned THEIC-containing polyesterimide insulated wire, THEIC-containing polyesteramide-imide insulated wire, aromatic polyamide-imide insulated wire, and polyimide-insulated wire is H type (180 ° C) or higher, its solderability is high. In addition, there is no solder peeling property.

On the other hand, the demands on the winding characteristics for insulated wires are becoming more and more stringent, and it is required to withstand the mechanical load during high-speed winding. Thermal shock resistance, crazing resistance, etc. are also required.

For these requirements, it is known that the aromatic polyamide-imide insulated electric wire is the most excellent, but these aromatic polyamide-imide insulated electric wires have excessive characteristics to meet the above-mentioned required characteristics, and It is extremely expensive and does not have solder releasability. Therefore, as an insulated wire having these required characteristics and an appropriate price, a multi-structure insulated wire combining the respective features has been developed.

The insulated wire most commonly used as a multi-structure insulated wire with heat resistance of class F (155 ° C) or higher is F
Glycerin-containing polyester imide insulating paint, F to H-type THEIC-containing polyester insulating paint, or H-type T
A double-structure insulated wire in which an insulating layer coated and baked with a HEIC-containing polyesterimide insulating coating is used as a lower layer, and an aromatic polyamideimide insulating coating is coated and baked as an upper layer.

However, since this multi-structure insulated wire uses an aromatic polyamide-imide insulating material, the terminal stripping process becomes difficult. In particular, aromatic polyamide-imide insulating materials have excellent chemical resistance, and since it is difficult for the lower layer itself to separate the solder, it is common for multi-layer insulated wires that combine these to have solder peelability. It does not have

As a result of intensive research to meet the above-mentioned demand, the present inventors have shown that, in an insulated wire having a multiple structure using an inexpensive cresol-soluble aromatic polyester amide imide insulating coating as an upper layer as an alternative to an aromatic polyamide imide insulating material,
The inventors have found a new excellent insulated wire having improved heat resistance (TI 200 ° C. or higher) of types F to H and high softening temperature (330 ° C. or higher) while improving the solder peeling property.

(Means for Solving Problems) That is, the present invention provides (A) a divalent carboxylic acid containing a five-membered ring imide group or a derivative thereof or a mixture thereof, and (B) a trivalent carboxylic acid or a mixture thereof. A derivative or a mixture thereof, (C) a dihydric alcohol, and (D) a trihydric aliphatic alcohol, wherein (A) is 5 to 20 equivalent%,
(B) 10 to 30 equivalent%, (C) 25 to 60 equivalent%, and (D) 10 to 40 equivalent% in the ratio of polyesterimide resin obtained by reacting in the presence of an organic solvent. A heat-resistant insulated wire capable of soldering, characterized in that an insulating paint is applied onto a conductor and baked, and then an insulating paint containing a cresol-soluble linear polyesteramideimide resin is applied and baked onto the conductor.

(Function) The insulated wire of the present invention is an insulated wire having a multiple structure in which a specific polyesterimide-based insulating material and a cresol-soluble linear polyesteramideimide insulating material are combined, and has excellent thermal, mechanical and electrical properties. It also has good solder releasability while having chemical properties.

The present inventor has a high softening temperature of about 330 ° C. or higher and a critical temperature of TI 200 ° C. or higher, although the solder peeling property and the heat resistance of the insulated wire are completely contradictory properties.
The inventors have found a novel polyesterimide / linear polyesteramideimide insulated wire having a solder releasability of not higher than ° C. The solder releasability at 450 ° C. or lower in the present invention is imparted by the polyesterimide insulating layer having a predetermined structure, and an insulated wire having both excellent solder releasability and excellent heat resistance is provided.

(Preferred Embodiment) Next, the present invention will be described in more detail with reference to preferred embodiments.

The polyesterimide resin, which is the main component for producing the polyesterimide insulating coating used in the present invention, uses the above-mentioned components (A) and (B) as the acid component and the above-mentioned (C) component as the alcohol component. And component (D), which are obtained by esterification of these according to a conventional method. Generally, the above raw materials are almost used as they are, but their precursors can also be used.

(A) as a constituent factor of the polyesterimide resin,
In (B), (C) and (D), (A) is 5 to 20 equivalent%, (B) is 10 to 30 equivalent%, and (C) is 25 to 60 equivalent%.
It is preferable that the main components are those obtained by reacting (D) with 10 to 40 equivalent%.

When (A) is less than 5 equivalent% in the above-mentioned use amount, the resulting insulated wire has insufficient solder releasability and thermal shock resistance. On the other hand, when it exceeds 20 equivalent%, it is costly in view of raw materials. This is not preferable because it becomes high and the flexibility of the coating is also reduced. If (B) is less than 10 equivalent%, the resulting insulated wire has insufficient solder releasability,
On the other hand, when it exceeds 30 equivalent%, it is not preferable because the resin is difficult to synthesize and the flexibility is lowered. or,
If the content of (C) is less than 25 equivalent%, the flexibility of the coating of the obtained insulated electric wire is remarkably reduced, while if it is more than 60 equivalent%, the solder releasability is deteriorated. On the other hand, if the content of (D) is less than 10 equivalent%, the softening temperature of the coating of the obtained insulated wire is lowered, whereas if it exceeds 40 equivalent%, the peeling property of solder is deteriorated, which is not preferable.

Therefore, in order to satisfy the solder releasability and the softening temperature of the polyesterimide resin and the heat resistance of the F type in a well-balanced manner, the total content of (A) and (B) is most preferably 30 to 40 equivalent%, and (C) And the total of (D) is 60 to 70
A resin obtained by reacting so as to be equivalent% is preferable.

The divalent carboxylic acid containing a five-membered imide group or a derivative thereof or a mixture (A) thereof used in the present invention can be prepared by the following method (a) by a conventionally known method.
And those obtained by reacting (b) with (b) or (a) with (c).

(A) An aromatic carboxylic anhydride containing at least one other reactive group in addition to the 5-membered carboxylic anhydride group. This latter reactive group is, for example, a carboxyl group, a carboxylic anhydride group or a hydroxyl group.

In place of the five-membered carboxylic acid anhydride group, two carboxyl groups bonded to adjacent carbon atoms or their esters and half-esters and imide groups can be formed, as long as they can form the following (b). Half amides with the primary amines obtained can also be used.

(B) A primary amine containing at least one other reactive group in addition to the primary amino group. This latter reactive group is a carboxyl group, a hydroxyl group or even a primary amino group.

Instead of a primary amine, as long as the attached primary amino group can form an imide group,
The amine salts, amides, lactams or polyamides may also be used.

(C) Polyisocyanate Examples of the compound (a) having a five-membered carboxylic acid anhydride group and other functional groups include tricarboxylic acid anhydrides, for example, trimellitic acid anhydride, hemimellitic acid anhydride, 1,2,5-naphthalene tricarboxylic acid anhydride, 2,3,6-naphthalene tricarboxylic acid anhydride, 1,8,4-naphthalene tricarboxylic acid anhydride, 3,4,4'-diphenyl tricarboxylic acid anhydride, Examples include 3,4,4'-diphenylmethane tricarboxylic acid anhydride, 3,4,4'-diphenyl ether tricarboxylic acid anhydride, and 3,4,4'-benzophenone tricarboxylic acid anhydride.

Examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, merofaniic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,8,4,5-naphthalene tetraanhydride Carboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyltetracarboxylic dianhydride, 3,3', 4,4 ' -Diphenyl ether tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyl methane tetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, etc. Among them, particularly useful are trimellitic anhydrides.

Examples of the compound (b) having a primary amino group and other functional groups include ethylenediami, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, and fatty acid having octamethylenediamine degree. Group diamines, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,3 ' -Diaminodiphenyl, 3,3'-diaminodiphenyl sulfone, 3,3'-dimethyl-4,4'-bisphenyldiamine, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, m-phenylenediamine, p- Phenylenediamine, m-xylylenediamine, p-xylylene Aromatic diamines such as amines and 1-isopropyl-2,4-metaphenylenediamine (particularly preferred are aromatic diamines), and further, for example, 3- (p-aminocyclohexyl) methanediaminopropyl, 3-methyl- Branched aliphatic diamites such as heptanemethinediamine, 4,4'-dimethylheptamethinediamine, 2,5-dimethylhexamethylenediamine, 2,5-dimethylheptamethinediamine, and further, for example, 1,4-diaminocyclohexane. Alicyclic diamines such as 1,10-diamino-1,10-dimethyldecane, and further amino alcohols such as monoethanolamine, monopropanolamine and dimethylethanolamine, and, for example, glycochol, aminopropionic acid, Aminocarboxylic acids such as aminocaproic acid and aminobenzoic acid It may be used.

Examples of the compound of polyisocyanate (C) include mononuclear polyisocyanates such as m-phenylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6-tolylene diisocyanate, which have a large number of nuclei. Examples of the aromatic polyisocyanate compound having, diphenyl ether-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, diphenylmethane-2,2'-diisocyanate, diphenylsulfone- There are 4,4'-diisocyanate, diphenylthioether-4,4'-diisocyanate, naphthalene diisocyanate and the like, and further hexamethylene diisocyanate, xylene diisocyanate and the like.

Further, so-called stabilized isocyanates obtained by stabilizing the isocyanate groups of these polyisocyanates with phenolic hydroxyl groups can also be used.

As the divalent carboxylic acid containing a 5-membered imide group, 2 mol of trimellitic anhydride and 1 mol of 4,4'-diaminodiphenylmethane, 1 mol of 4,4'-diaminodiphenyl ether and diphenylmethane-4, are preferred. It is a divalent carboxylic acid obtained from 1 mol of 4'-diisocyanate or 1 mol of diphenyl ether-4,4'-diisocyanate. The divalent carboxylic acid containing these five-membered imide groups is usually obtained by reacting (a) with (b) or (a) with (c) in a solvent.

As a solvent used when a divalent carboxylic acid containing a 5-membered imide group is obtained in a solvent, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N, N -Diethylformamide, N, N-diethylacetamide, cresylic acid, phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,
6-xylenol, 3,4-xylenol, 3,5-xylenol, aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, ethers, ketones and esters can also be used. , Benzene, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, petroleum naphtha, coal tar naphtha, solvent naphtha, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate and the like. These can be used not only alone but also as a mixed solvent.

Derivatives of a divalent carboxylic acid containing a five-membered imide group include esters and halides.

Examples of the trivalent carboxylic acid or its derivative (B) include, for example, trimellitic acid, trimemic acid, and further trimellitic acid anhydride, hemimellitic acid anhydride, 1,2,5-naphthalenetricarboxylic acid. Anhydride, 2,3,6-naphthalene tricarboxylic anhydride, 1,8,4-naphthalene tricarboxylic anhydride, 3,4,4'-diphenyl tricarboxylic anhydride, 3,4,4'-diphenyl Examples thereof include methanetricarboxylic acid anhydride, 3,4,4'-diphenyl ether tricarboxylic acid anhydride, and 3,4,4'-benzophenone tricarboxylic acid anhydride.

Derivatives of these trivalent carboxylic acids include their esters, but particularly useful ones are trimellitic anhydride and trimellitic acid.

Examples of the dihydric alcohol (C) include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propanediol, various butanes, pentanes, and Or hexanediol,
For example, 1,3- or 1,4-butanediol 1,5-pentanediol 1,6-hexanediol, butene-2-diol-1,4, 2,2-dimethylpropanediol-1,3, 2- Ethyl-2-butyl-propanediol-1,3,1,4-dimethylolcyclohexane, 1,4-butenediol, water-added bisphenols (for example, water-added P, P'-dihydroxydiphenylpropane or its homologues) ), Cyclic glycols such as 2,2,4,4-tetramethyl-1,3-cyclobutanediol, hydroquinone-di-β-hydroxyethyl-ether, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol. , Trimethylene glycol, hexylene glycol, octylene glycol and the like.

Particularly preferred are ethylene glycol and 1,6-
Hexanediol.

The trihydric aliphatic alcohol used in the present invention does not contain an aromatic or heterocyclic ring at any position in the molecule. If a trihydric alcohol or a tetrahydric or higher alcohol containing an aromatic or a heterocyclic ring is used, it is not preferable to add the trivalent alcohol because the releasability of the solder is significantly impaired.

Examples of these trihydric aliphatic alcohols (D) include, for example, glycerin, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, etc., and particularly preferred is glycerin. is there.

In the present invention, the following method can be mentioned as an embodiment in the case of synthesizing a polyesterimide resin using these raw material compounds.

(1) The divalent carboxylic acid (A) containing a five-membered imide group is used as the raw material (a) described in the section of the divalent carboxylic acid (A) containing a five-membered imide group (A). (B) or (a) and (c) are reacted in a solvent to form.

Other raw materials (B), (C) and (D) are added to this system, and the esterification reaction is advanced at 200 to 210 ° C. for 3 to 7 hours to synthesize a polyesterimide resin solution. Method.

(2) The divalent carboxylic acid (A) containing a five-membered imide group is combined with the raw materials (a) and (b) described in the section of the divalent carboxylic acid (A) containing a five-membered imide group. ) Or (a) and (c) are formed by reacting in a solvent.

To this system, the polyester intermediates synthesized from the other raw materials (B), (C) and (D) were added, and 200
A method of synthesizing a polyesterimide resin solution by performing an esterification reaction at a temperature of from about 210 ° C. to about 210 ° C. for from 3 to 5 hours.

(3) The system of the polyester intermediate obtained by the method of (2) above contains a five-membered ring imide group synthesized from the above-mentioned raw materials (a) and (b) or (a) and (c). A method for synthesizing a polyesterimide resin solution by adding the divalent carboxylic acid (A) mentioned above and advancing the esterification reaction at 200 to 210 ° C. for 3 to 5 hours.

(4) The polyester intermediate solution obtained by the method of (2) is cooled to 100 ° C. or lower, and the starting raw material of the divalent carboxylic acid (A) containing a five-membered imide group (A) is used. And (ii) are added to form a divalent carboxylic acid (A) containing an imide group at 120 to 160 ° C.,
A method for synthesizing a polyesterimide resin solution by heating to 200 ° C and advancing the esterification reaction at 200 to 210 ° C for 3 to 5 hours.

(5) The above-mentioned raw materials (a) and (b) which are starting raw materials for the divalent carboxylic acid (A) containing a five-membered ring imide group
And (B), (C) and (D) which are the other raw materials are mixed together, and an imidization reaction is carried out at 120 to 160 ° C in this system, and the temperature is raised to 200 ° C. There is a simultaneous reaction method in which a polyesterimide resin solution is synthesized by directly performing an esterification reaction at 210 to 210 ° C. for 3 to 5 hours.

The polyesterimide resin obtained by the reaction of the raw materials (A), (B), (C) and (D) is dissolved in a solvent or adjusted to an appropriate concentration to obtain the insulating coating used in the present invention.

Examples of the solvent include a solvent having a phenolic hydroxyl group,
For example, phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4
-Xylenol, 3,5-xylenol, on-propylphenol, 2,4,6-trimethylphenol, 2,3,5-
Trimethylphenol, 2,4,5-trimethylphenol, 4-ethyl-2-methylphenol, 5-ethyl-
It is preferable to use 2-methylphenol and cresylic acid which is a mixture thereof. In addition, N-methyl-
Polar solvents such as 2-pyrrolidone and N, N-dimethylacetamide can be used. As the diluting solvent, for example, aliphatic hydrocarbons, aromatic hydrocarbons, ethers, acetals, ketones, esters and the like can be used.

Examples of aliphatic hydrocarbons and aromatic hydrocarbons include n-heptane, n-octane, cyclohexane, decalin, dipentene, pinene, p-menthane, decane,
Dodecane, tetradecane, benzene, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, amylbenzene, p-cymene, tetralin or a mixture thereof, petroleum naphtha, coal tar naphtha, solvent naphtha and the like can be mentioned.

The most useful solvent for the polyesterimide resin insulating coating used in the present invention is cresylic acid. Cresylic acid
It has a boiling range of 180 to 230 ° C., which contains phenol, o-cresol, m-cresol, p-cresol, xylenols.

Part of this cresylic acid is converted to an aromatic hydrocarbon, for example,
By diluting with petroleum naphtha, coal tar naphtha, solvent naphtha, or the like, the workability in manufacturing an insulated wire by applying and baking an insulating paint on a conductor can be improved.

Examples of these diluting solvents include xylene, Solvent Naphtha No. 2, Solvesso # 100 and Solvesso # 1.
50 and the like, and the amount of these used is 0 to
It is 30%, but preferably 10 to 20%.

When manufacturing the insulated wire by applying and baking the insulating paint thus obtained on the conductor, use of a small amount of metal desiccant improves the surface smoothness of the insulated wire and increases the take-up speed. This is preferable because the workability can be improved and the workability can be further improved.

As these metal desiccants, zinc, calcium or lead octoate, linoleate and the like are useful, for example,
Examples thereof include zinc octoate, calcium naphthenate, zinc naphthenate, lead naphthenate, lead linonate, calcium linoleate, and zinc resinate. Other examples include manganese naphthenate and cobalt naphthenate.

However, a further advantage is to use compounds of titanic acid and zirconic acid instead of these metal desiccants.

Representative titanic acid compounds include, for example, tetraalkyl titanates such as tetraisopropyl titanate, tetrabutyl titanate, tetrahexyl titanate, tetramethyl titanate, tetrapropyl titanate, and tetraoctyl titanate.

Also useful are tetraalkyltitanium chelates obtained by reacting tetraalkyltitanate with octyleneglycol, triethanolamine, 2,4-pentadiene, acetoacetic acid ester and the like.

Further, tetraalkyl titanium acylate obtained by reacting tetraalkyl titanate with stearic acid and the like is also useful.

Examples of the zirconic acid compound include tetraalkyl zirconates, zirconium chelates, and zirconium acylates corresponding to the above titanic acid compounds.

The addition amount of these metal compounds is 0.1 to 6.0% by weight, preferably 1 to 3% by weight, based on the solid content of the insulating paint.

Further, a stabilized polyisocyanate obtained by blocking the isocyanate group of polyisocyanate with phenol, cresol or the like can be used as a curing agent. Examples of these include cyclic trimers of 2,4-tolylene diisocyanate, cyclic trimers of 2,6-tolylene diisocyanate, dimers of diphenylmethane-4,4'-diisocyanate, 3 moles of Reaction product of diphenylmethane-4,4'-diisocyanate with 1 mol of trimethylolpropane, reaction product of 3 mol of 2,4-tolylene diisocyanate with 1 mol of trimethylolpropane, 3 mol of 2 , 6-
Reaction product of tolylene diisocyanate with 1 mol of trimethylol propane, 3 mol of 2,4-tolylene diisocyanate with 1 mol of trimethylol ethane, 3 mol of 2,6-tolylene diisocyanate Reaction product with 1 mole of trimethylolethane, mixed 3
A reaction product of 2,4- and 2,6-tolylene diisocyanate in moles with 1 mole of trimethylolpropane, a cyclic trimer in which 2,4- and 2,6-tolylene diisocyanate is mixed with phenol or Examples include stabilized polyisocyanates blocked with cresol. Further, stabilized isocyanates obtained by blocking diphenylmethane-4,4'-diisocyanate with xylenol are also useful.

In addition, the appearance workability of the insulated wire can be further improved by adding 1 to 5% by weight of a phenol-formaldehyde resin, a melamine-formaldehyde resin, a cresol-formaldehyde resin, a xylene-formaldehyde resin, an epoxy resin and a silicone resin. . If the content of these resins is less than 1% by weight, there is no effect in improving workability. Addition of 5% by weight or more is not preferable because carbides are remarkably formed at the time of solder peeling. Particularly preferred resins are a phenol-formaldehyde resin and a xylene-formaldehyde resin. By adding these resins in an amount of 1 to 2% by weight, the appearance workability can be improved without impairing the solder peelability of the insulated wire.

The linear polyester amide imide insulating coating material in the present invention is an insulating coating material containing a linear polyester amide imide resin or a linear polyester amide imide precursor resin as a main component.

Regarding the method for producing a linear polyesteramide imide resin or its precursor resin which is a main component of a cresol-soluble linear polyester amide imide insulating coating, for example, JP-B-42-11624, JP-B-45-13597, JP-B-45-18316, JP-B-45-18678, JP-B-46-05089, JP-B-47-23920, JP-B-47-26116, JP-B-47-40717, JP-B-47407 47-46480, JP-B-48-03717, JP-B-49-04709, JP-B-50-21676, JP-B-50-21677, JP-B-50-23409, JP-B-50- 23410, Japanese Patent Publication No. 50-35555, Japanese Patent Publication No. 51-07689, Japanese Patent Publication No. 51-15859, Japanese Patent Publication No. 51-23999, Japanese Patent Publication No. 51-46155, Japanese Patent Publication No. 51-46156. Gazette, Japanese Patent Publication No. 52-07032, Japanese Patent Publication No. 52-31543, Japanese Patent Publication No. 52-39718, Japanese Patent Publication JP 54-20661 B and JP 54-38296 B.

The most typical production method is trimellitic anhydride, a dibasic acid is reacted with diphenylmethane-4,4'-diisocyanate, and the terminal group of the dicarboxylic acid containing an amide group and an imide group is diphenyl carbonate. A cresol-soluble linear polyester amide imide resin insulating coating, which is a reaction product of the intermediate masked with 1. and the linear polyester composition, is useful.

The above is the content of the polyesterimide insulating paint and the cresol-soluble polyesteramideimide insulating paint used in the present invention, and the solderable heat-resistant insulated wire of the present invention is obtained by applying and baking the above polyesterimide insulating paint on a conductor. To a predetermined coating thickness, and the above polyester amide imide resin coating material is similarly applied and baked thereon to provide a predetermined coating thickness.

The conductor used at this time is, for example, copper, silver or stainless steel wire, and the applicable conductor diameter may be any diameter from an ultrafine wire to a thick wire, and is limited to a specific conductor diameter. Not a thing. Generally, the diameter is about 0.050 or more
It is mainly applied to copper wire of about 2.0 mm.

The method of forming a different type of insulating film on the conductor may be based on a conventionally known method, for example, by applying an insulating coating by a method such as a felt drawing method or a die drawing method,
The desired insulating film is formed by continuously passing it in a plurality of baking ovens at a temperature of about 350 to 550 ° C. or several times. The thickness of the insulating film is the coating thickness specified in JIS, NEMA or IEC standards, and the inner and lower layers occupy about 60 to 90% by weight of the whole, but preferably about 70 to 80% by weight. Is the amount occupying. When such a film thickness cannot be formed by one application and baking,
The coating and baking may be repeated as many times as necessary.

(Effect) According to the present invention as described above, by forming the lower layer of the double-layered insulating film from a specific polyesterimide resin, it is possible to perform soldering treatment in which the softening temperature, the solder peeling property and the critical temperature are remarkably improved. A heat resistant insulated wire is economically provided.

The contents of the present invention will be specifically described in the following reference examples, comparative examples and examples, but the present invention is not limited to these examples.

Reference Example 1 192 g (1.0 mol) of trimellitic anhydride was added to cresol 6
Then, 99 g (0.5 mol) of 4,4'-diaminodiphenylmethane was added, and the mixture was reacted at 140 ° C. for 6 hours. After cooling, a pale yellow precipitate of fine crystals was obtained. This was washed several times with alcohol and filtered to obtain a 5-membered ring diimidedicarboxylic acid.

Reference Example 2 192 g (1.0 mol) of trimellitic anhydride was added to cresol 6
Then, 100 g (0.5 mol) of 4,4'-diaminodiphenyl ether was added, and the mixture was reacted at 180 ° C. for 4 hours. After cooling, a brown crystalline precipitate was obtained. This was washed several times with alcohol and filtered to obtain a 5-membered ring diimidedicarboxylic acid.

Reference Example 3 192 g (1.0 mol) of trimellitic anhydride was added to cresol 6
After addition of 124 g (0.5 mol) of 4,4'-diaminodiphenylsulfone, the mixture was added to 160 g.
The reaction was carried out at ℃ for 4 hours. After cooling, a white crystalline precipitate was obtained. This was washed several times with alcohol and filtered to obtain a 5-membered ring diimidedicarboxylic acid.

Reference Example 4 192 g (1.0 mol) of trimellitic anhydride was added to cresol 6
00 g, then 108 g of p-phenylenediamine
(0.5 mol) was added and the mixture was reacted at 180 ° C. for 4 hours. After cooling, a greenish brown crystalline precipitate was obtained. This was washed several times with alcohol and filtered to obtain a 5-membered ring diimidedicarboxylic acid.

Reference Example 5 192 g (1.0 mol) of trimellitic anhydride was added to cresol 6
Add to 00g, then add 58g of hexamethylenediamine (0.
5 mol) was added. This mixture was reacted at 180 ° C. for 4 hours. After cooling, a white crystalline precipitate was obtained. This was washed several times with alcohol and filtered to obtain a 5-membered ring diimidedicarboxylic acid.

Reference Example 6 192 g (1.0 mol) of trimellitic anhydride and 137 g (1.0 mol) of p-aminobenzoic acid were added and dispersed in 600 g of cresol. This mixture was reacted at 150 ° C. for 4 hours. After cooling, a fine-grained precipitate of a white powder was obtained. This was washed several times with alcohol and filtered to obtain a 5-membered ring diimidedicarboxylic acid.

Reference Example 7 192 g (1.0 mol) of trimellitic anhydride and 125 g (0.5 mol) of diphenylmethane-4,4'-diisocyanate were used in 150 g of solvent naphtha (Nisseki Chemical Hisol # 100).
And the mixture was reacted at 150 ° C. for 4 hours. Significant foaming occurred as the reaction proceeded and then solidified. The solidified product was pulverized to obtain a 5-membered ring diimidedicarboxylic acid.

Reference Example 8 192 g (1.0 mol) of trimellitic anhydride and 126 g (0.5 mol) of diphenyl ether-4,4'-diisocyanate
And Solvent Naphtha (Nisseki Chemical Hisol # 100) 150
g, and the mixture was reacted at 150 ° C. for 4 hours. Significant foaming occurred as the reaction proceeded and then solidified. The solidified product was pulverized to obtain a 5-membered ring diimidedicarboxylic acid.

Reference Example 9 125 g (0.65 mol) of trimellitic anhydride, 42 g (0.25 mol) of isophthalic acid and 130 g of cresol were put and heated to 100 ° C., and 200 g (0.8 mol) of diphenylmethane-4,4′-diisocyanate was added with stirring. Added. Then at 240 ℃ 3
React on time. Diphenyl carbonate 20g,
1 g of tetrabutyl titanate was added and reacted for 2 hours. After the reaction, 480 g of cresol was added. Separately, polyethylene terephthalate (200 g), diphenyl carbonate (100 g) and tetrabutyl titanate (2 g) were added and reacted at 240 ° C. for 2 hours. 80g of this oligomer was added to the above reaction product.
The reaction was carried out at 80 ° C for 1 hour. Next, 8 g of tetrabutyl titanate was added, and a linear polyester amide imide insulating coating having a nonvolatile content of 30% was obtained with a mixed solvent of cresol / xylene 7/3.

Example 1 equipped with a stirrer, nitrogen gas introduction tube, thermometer and cooling tube
In a 2,000 cc four-necked flask, as in Reference Example 1,
192 g (1.0 mol) of trimellitic anhydride in cresol 600
It was added to and dispersed in g. Next, 99 g (0.5 mol) of 4,4'-diaminodiphenylmethane was added to obtain 273 g (1.0 equivalent) of a five-membered ring diimidedicarboxylic acid. This mixture was reacted at 150 ° C. for 3 hours. After cooling this system to 100 ° C or lower, 96 g of trimellitic anhydride (1.5 equivalents), 105 g of ethylene glycol (3.4 equivalents) and 26 g of glycerin (0.85 equivalents)
(Equivalent amount) was added, and the mixture was stirred with heating to 200 ° C. over 6 hours and allowed to react at this temperature for 5 hours.

The five-membered diimidedicarboxylic acid reacts with the produced polyester component to obtain a transparent resin solution. The degree of the reaction was measured by increasing the viscosity, and samples were taken over time. At the end of the reaction, when the viscosity of the resin sample reached Z ₃ (Gardner viscometer) in 40% cresol, cresol was added to bring the nonvolatile content to 40%. % Resin solution.
Furthermore, 2% of tetrabutyl titanate and te
2% of a phenol-formaldehyde resin containing rt-butylphenol as a main component was added to obtain an insulating paint.

Example 2 equipped with a stirrer, nitrogen gas introduction tube, thermometer and cooling tube
In a 1,000 cc four-necked flask, trimellitic anhydride 192
g (1.0 mol) was added and dispersed in 600 g of cresol. Next, 99 g of 4,4'-diaminodiphenylmethane (0.5
Mol), and the five-membered ring diimidedicarboxylic acid 273 g
(1.0 equivalent). The mixture is reacted at 150 ° C. for 3 hours and then cooled to 100 ° C. or lower. Separately, the same as above 500
In a cc reaction vessel, 96 g of trimellitic anhydride (1.5 equivalents), 105 g of ethylene glycol (3.4 equivalents), 26 g of glycerin (0.85 equivalents) and 30 g of xylene were mixed and stirred to obtain 200
The temperature was raised to 0 ° C over 6 hours, and the reaction was carried out at this temperature for 5 hours. After this polyester component is cooled to 80 ° C., it is added to the dispersion solution of the above-mentioned five-membered diimidedicarboxylic acid and the reaction is started again. The reaction is carried out at 200 ° C. for 5 to 7 hours. The five-membered diimidedicarboxylic acid reacts with the polyester component to obtain a transparent resin solution. The degree of the reaction was measured by increasing the viscosity, and samples were taken over time. At the end of the reaction, the viscosity of the resin sample is 40
% When cresol becomes Z ₃ + (Gardner viscometer), cresol is added to make a nonvolatile content of 40%, and Nisseki Chemical Hisol # 100 is added to this to make a resin solution of a nonvolatile content of 35%.

The resin solution thus obtained was treated as in Example 1 to give an insulating coating.

Example 3 equipped with a stirrer, a nitrogen gas introduction tube, a thermometer and a cooling tube
96 g of trimellitic anhydride in a 2,000 cc four-necked flask
(1.5 equivalents), 105 g (3.4 equivalents) of ethylene glycol, 26 g (0.85 equivalents) of glycerin, and 30 g of xylene were mixed and stirred and reacted at 200 ° C. for 6 hours to synthesize a polyester component. While adding 300 g of cresol to this,
After cooling to 80 ℃, trimellitic anhydride 192g (1.0
Mol) and 96 g of 4,4'-diaminodiphenylmethane (0.
5 mol) and the reaction temperature is raised to 200 ° C. During this period, a five-membered diimidedicarboxylic acid (1.
This system becomes cloudy and highly viscous due to the generation and precipitation of (0 equivalent), but as the temperature rises, it is absorbed by the polyester component and becomes a solution, and then a transparent resin solution is formed. The reaction temperature is kept at 200 ° C. for 1-2 hours. The degree of the reaction was measured by increasing the viscosity, and samples were taken over time. At the end of the reaction, when the viscosity of the resin sample reached Z ₂ (Gardner viscometer) in 40% cresol, cresol was added to make the nonvolatile content 40%.
Add 0 to make a resin solution with a nonvolatile content of 35%.

The resin solution thus obtained was treated as in Example 1 to give an insulating coating.

Example 4 equipped with a stirrer, a nitrogen gas introduction tube, a thermometer and a cooling tube
In a 2,000 cc four-necked flask, trimellitic anhydride 288
g (2.5 equivalents), 99 g of 4,4'-diaminodiphenylmethane
(0.5 mol), 105 g (3.4 equivalents) of ethylene glycol, 26 g (0.85 equivalents) of glycerin and 300 g of cresol are added, mixed and stirred, and heated to 200 ° C. over 6 hours. During this time, a five-membered ring diimidedicarboxylic acid is formed at 140 ° C.,
When deposited, it becomes cloudy and exhibits high viscosity. As the temperature rises, the five-membered ring diimidedicarboxylic acid deposited is gradually absorbed by the polyester component. The reaction is continued at 200 ° C. for 5 hours. The degree of the reaction was measured by increasing the viscosity, and samples were taken over time. At the end of the reaction, the viscosity of the resin sample is 40
% When cresol becomes Z ₂ + (Gardner viscometer), cresol is added to make a non-volatile component 40%, and the above-mentioned Nisseki Chemical Hysol # 100 is added to make a resin solution having a non-volatile content of 35%.

The resin solution thus obtained was treated as in Example 1 to give an insulating coating.

Example 5 105 g of ethylene glycol in the formulation of Example 3
(3.4 equivalents) instead of 1,6-hexanediol 200g
An insulating coating material was obtained in the same manner as in Example 3 by using (3.4 equivalents).

Example 6 105 g of ethylene glycol in the formulation example of Example 3
Instead of (3.4 equivalents) 200 g of 1,6-hexanediol (3.
4 equivalents) is replaced by 1,1, instead of 26 g (0.85 equivalents) of glycerin.
An insulating paint was obtained in the same manner as in Example 3 using 38 g (0.85 equivalent) of 1-trimethylolpropane.

Example 7 58 g of trimellitic anhydride (0.9 equivalent), 93 g of ethylene glycol (3.0 equivalent), 92 g of glycerin (3.0 equivalent), 20 g of xylene, 900 g of cresol, 384 of trimellitic anhydride
g (2.0 mol) and 4,4'-diaminodiphenylmethane 1
98 g (1.0 mol) [that is, diimidedicarboxylic acid (2.0 equivalent)] was reacted in the same manner as in Example 3 and an insulating coating material was similarly obtained.

Example 8 250 g (3.9 equivalents) of trimellitic anhydride, 310 g (10.0 equivalents) of ethylene glycol, 92 g (3.0 equivalents) of glycerin, 20 g of xylene, 1100 g of cresol, 192 g (1.0 mol) of trimellitic anhydride and 4,4 99 g (0.5 mol) of'-diaminodiphenylmethane [that is, diimidedicarboxylic acid (1.0 equivalent)] was reacted in the same manner as in Example 3 and an insulating coating material was similarly obtained.

Examples 9 to 13 192 g of trimellitic anhydride in the formulation of Example 2
(1.0 mol) and 99 g of 4,4'-diaminodiphenylmethane
An insulating coating material was obtained in the same manner as in Example 2 except that the five-membered diimidedicarboxylic acid of Reference Examples 2 to 6 was used instead of (0.5 mol).

Example 14 192 g of trimellitic anhydride in the formulation of Example 3
(1.0 mol) and 99 g of 4,4'-diaminodiphenylmethane
An insulating coating material was obtained in the same manner as in Example 3 except that the five-membered diimidedicarboxylic acid of Reference Example 8 was used instead of (0.5 mol).

Comparative Example 1 equipped with a stirrer, a nitrogen gas introduction pipe, a thermometer and a cooling pipe
Add 340 g (3.5 equivalents) of dimethyl terephthalate, 155 g (5.0 equivalents) of ethylene glycol, 154 g (5.0 equivalents) of glycerin, 0.4 g of litharge and 300 g of xylene to a 2,000 cc four-necked flask and mix and stir until 180 ° C. The temperature was raised and the reaction was carried out at this temperature for 5 hours. 410 g (1.5 equivalents) of the five-membered diimidedicarboxylic acid obtained in Reference Example 7
Is gradually added, and the reaction temperature is raised to 200 ° C. During this time, the five-membered diimide dicarboxylic acid reacts with the polyester component to obtain a transparent resin solution. Then raise the reaction temperature
After raising the temperature to 240 ° C and keeping it for 1 to 2 hours,
Vacuum distillation was performed, and when the mixture became sufficiently viscous, cresol was added to make the nonvolatile content 40%.
To obtain a resin solution having a nonvolatile content of 35%.

Furthermore, tetrabutyl titanate (3% of resin content) was added to obtain an insulating paint.

Comparative Example 2 A stirrer, a nitrogen gas inlet tube, a thermometer, and a cooling tube were provided.
Add 340 g (3.5 equivalents) of dimethyl terephthalate, 155 g (5.0 equivalents) of ethylene glycol, 154 g (5.0 equivalents) of glycerin, 0.4 g of litharge and 300 g of xylene to a 2,000 cc four-necked flask and mix and stir until 180 ° C. The temperature was raised and the reaction was carried out at this temperature for 5 hours. After cooling this to 80 ℃, 288 g (1.5 mol) of trimellitic anhydride and 4,4 '
149 g (0.75 mol) of diaminodiphenylmethane are added and the reaction temperature is raised to 200.degree. 140 ~
The five-membered diimide dicarboxylic acid formed at 150 ° C. reacts with the polyester component to obtain a transparent resin solution. Then, the reaction temperature was raised to 240 ° C. and kept for 1 to 2 hours, and distilled under reduced pressure. When the mixture became sufficiently viscous, cresol was added to make the nonvolatile content 40%. Comparative Example 1
The same treatment was performed to obtain an insulating paint.

Comparative Example 3 An insulating coating material was obtained in the same manner as in Comparative Example 2 except that 295 g (5.0 equivalents) of 1,6-hexanediol was used instead of 155 g (5.0 equivalents) of ethylene glycol in Comparative Example 2.

In conducting the performance test of these insulating paints, coating and baking were performed under the following conditions to manufacture the insulated wires of the present invention and the comparative example.

Conductor diameter: 0.32 m / m Baking furnace; Horizontal baking furnace with an effective furnace length of 2.5 m Baking temperature: 500 ° C (high temperature) Drawing method: Die method Number of coatings: Lower layer 6 times + Upper layer 3 times Lower layer: Polyesterimide insulating paint Upper layer : Linear polyester amide imide insulating coating prepared in Reference Example 9 Film thickness: 0.025 to 0.03 m / m The test method was according to JIS C 3003-1984 enamel copper wire and enamel aluminum wire test method. The test results are as shown in Table 1. As is clear from the above test results, when the polyesterimide insulating coating according to the present invention is used, the softening temperature, the solder peeling property, and the critical temperature (TI) are remarkably higher than those using the conventional polyesterimide insulating coating. It is clear that it is improving.

The TI (Temperature Index) is IEC 251-1978 Met.
hods of test for winding wires Part 1: Enamelled ro
Compliant with und wires.

Continuation of the front page (56) References JP-A-57-65606 (JP, A) JP-B 52-50386 (JP, B2) JP-B 50-35555 (JP, B2)

Claims (1)

[Claims] (A) a divalent carboxylic acid having a five-membered imide group, a derivative thereof, or a mixture thereof;
(B) trivalent carboxylic acid or its derivative or a mixture thereof, (C) dihydric alcohol, and (D) trihydric aliphatic alcohol, wherein (A) is 5 to 20 equivalent%,
(B) 10 to 30 equivalent%, (C) 25 to 60 equivalent%, and (D) 10 to 40 equivalent% in the ratio of polyesterimide resin obtained by reacting in the presence of an organic solvent. A heat-resistant insulated wire capable of soldering, characterized in that an insulating paint is applied onto a conductor and baked, and then an insulating paint containing a cresol-soluble linear polyesteramide imide resin is applied and baked onto the conductor.