JPH0821268B2 - Insulated wire that can be soldered - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an insulated wire that can be treated with solder, and more particularly to an insulated wire coated with a polyester resin having excellent solder releasability.

(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 devices.

From these viewpoints, a material with excellent heat resistance is required as a coating material for insulated electric wires used in electric devices such as motors and transformers, and polyester insulated electric wires using an insulating coating containing polyester resin as a main component are required. B type (130
It is widely used as insulated wire from (° C) to F type (155 ° C).

Also, in order to reduce the size and weight of the equipment, it is necessary to make the wire thinner, and the thin polyester insulated wire is loaded with more load than before. Naturally, a higher performance polyester insulated wire is required. It came to be requested.

Also, because these polyester insulated wires are used in harsh environments, in addition to heat resistance, chemical resistance, solvent resistance,
It goes without saying that hydrolysis resistance and alkali resistance are required.

On the other hand, electrical equipment manufacturers are seeking rationalization of processes for cost reduction and demanding higher performance than conventional insulating paints.

As part of this, there are labor-saving and line-up processes for terminal stripping of insulated wires.

At present, there are various methods such as (1) mechanical peeling, (2) thermal decomposition peeling, (3) chemical peeling, and (4) solder peeling as the processing methods of the terminal peeling. Considering intactness and continuous processing, the above-mentioned solder peeling method (4) is most preferable.

However, although a polyester insulated electric wire made of a conventional polyester insulating coating has already been made into a line by peeling a chemical, it requires a certain period of time for immersion in the chemical and must be washed. Also, since it is dangerous in handling, we tried to make a line by peeling solder,
None of the conventional polyester insulated wires have solder releasability.

Insulated wires that can be subjected to solder peeling treatment include polyurethane insulated wires containing polyurethane resin as the main component and polyester imide insulated wires containing polyester imide resin as the main component. It has low E type (120 ° C) and the latter is F type (155
Although it has heat resistance of (° C.) to H type (180 ° C.), it is expensive because it contains a large amount of imide groups and is used only in a specific field.

Therefore, it is possible to perform solder stripping treatment from electrical equipment manufacturers, so-called solder stripping is possible, and heat resistance is B
There is a strong demand for insulated wires of types (130 ° C) to F (155 ° C).

In this field, the expression "possible for solder peeling treatment" means that when the insulated wire is immersed in a heated solder bath, the insulating coating is decomposed and removed at the immersed portion, and at this point the conductor is soldered. It means that soldering is easy because it is marked with, and it does not mean that soldering can be done directly.

In addition, recently, when soldering a large number of twisted insulated wires, it is possible to remove the insulating coating and solder it all at once by directly immersing the insulated wire covered with the insulating coating in a solder bath. It has increased. To do this,
Following immersion in the solder bath, the insulating coating should be removed as quickly or instantaneously as possible. It goes without saying that the shorter the immersion in the solder bath, the better.

When removing solder, the temperature of the molten solder bath is 450 ℃
When the temperature exceeds the above range, the oxidative deterioration of the solder bath further progresses, and the speed at which copper as a conductor dissolves in the solder increases, which causes a problem of thinning of the insulated wire.

As a result of earnest research to meet the above-mentioned demand, the present inventor has found that an insulated electric wire satisfying the above-mentioned demand can be obtained by using a specific polyester resin.

(Means for Solving Problems) That is, the present invention provides (A) at least one divalent carboxylic acid selected from terephthalic acid, isophthalic acid, lower alkyl esters thereof, phthalic acid and anhydrides thereof.
10 to 47 equivalent% and (B) trimellitic acid and / or its trivalent carboxylic acid 3 to 30 equivalent%,
(C) ethylene glycol, propylene glycol and
20 to 50 equivalent% of at least one dihydric alcohol selected from 1,6-hexanediol, and (D) glycerol and / or trihydric aliphatic alcohol of 1,1,1-trimethylolpropane 5 to 5 40 equivalent% [However, (A) ~
(D) is 100 equivalent%] and (A) and (B) are 30 to 50 equivalent% in total, and (C) and (D) are 50 to 70 equivalent% in total. It is an insulated wire capable of being soldered, characterized in that a polyester insulating coating material containing a polyester resin and an alkyl titanate obtained by reacting as described above is applied and baked on a conductor.

(Operation) The insulated wire of the present invention has excellent thermal, mechanical, electrical, and chemical properties and excellent solder peeling property by using an insulating coating material containing a specific polyester resin.

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

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

(A) as a constituent factor of the polyester resin,
In (B), (C) and (D), (A) is 10 to 47 equivalent%, (B) is 3 to 30 equivalent%, and (C) is 20 to 50 equivalent%.
And (D) are mainly reacted with 5 to 40 equivalent%. The total of (A) to (D) is 100 equivalent%.

When (A) is less than 10 equivalent% in the above-mentioned amount used, flexibility of the insulated wire of the present invention obtained by the above-mentioned insulating coating becomes insufficient, while when it exceeds 47 equivalent%, heat resistance becomes high. Is insufficient, which is not preferable. or,
If the content of (B) is less than 3 equivalent%, the resulting insulated wire has insufficient solder releasability. On the other hand, if it exceeds 30 equivalent%, it is difficult to synthesize the resin and the coating film is easily formed. Flexibility is reduced, which is not preferable. On the other hand, if the content of (C) is less than 20 equivalent%, the flexibility of the coating of the obtained insulated wire is remarkably reduced, while if it exceeds 50 equivalent%, the heat resistance is deteriorated. On the other hand, if the content of (D) is less than 5 equivalent%, the softening temperature of the coating of the obtained insulated electric wire is lowered, while if it exceeds 40 equivalent%, the solder releasability is poor, which is not preferable.

Therefore, in order to balance the solder releasability and other properties of the insulated wire with the above polyester insulating paint in a well-balanced manner, the total content of (A) and (B) is most preferably 30 to 50 equivalent%, and (C) And the sum of (D) is 50 to 70
It is preferable to use a resin obtained by reacting so as to be equivalent%.

The divalent carboxylic acid (A) used in the present invention is at least one divalent carboxylic acid selected from isophthalic acid, terephthalic acid, lower alkyl esters thereof, phthalic acid and anhydrides thereof and derivatives thereof.

Examples of the lower alkyl ester of the above acid include a lower dialkyl ester of the above carboxylic acid, for example, in the case of terephthalic acid, dimethyl terephthalate, diethyl terephthalate, dipropyl terephthalate, dibutyl terephthalate, diamyl terephthalate, dihexyl terephthalate, dioctyl terephthalate or a dioctyl terephthalate thereof. Half-esters such as monomethyl terephthalate may be mentioned.

Further, the above-mentioned carboxylic acid and its derivative can be used not only alone but also as a mixture thereof.

Particularly preferred as (A) is a case where isophthalic acid, terephthalic acid or a lower alkyl ester thereof, or a part of these is replaced with another carboxylic acid or a derivative thereof.

The trivalent carboxylic acid (B) is trimellitic acid and / or trimellitic anhydride.

The dihydric alcohol (C) is at least one selected from ethylene glycol, propylene glycol (for example, 1,2-propylene glycol, dipropylene glycol, etc.) 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.

These trihydric aliphatic alcohols (D) are glycerin and / or 1,1,1-trimethylolpropane,
Especially preferred is glycerin.

In the present invention, the following method can be mentioned as an embodiment for synthesizing a polyester resin using these raw material compounds.

(1) The raw materials (A), (C) and (D) are reacted at 180 to 230 ° C for 2 to 10 hours, then (B) is added and further esterified at 200 to 260 ° C. A method of synthesizing a polyester resin by advancing the reaction.

(2) The raw materials (B), (C) and (D) are reacted at 180 to 230 ° C for 2 to 10 hours, after which (A) is added and further esterified at 200 to 260 ° C. A method of synthesizing a polyester resin by advancing the reaction.

(3) Raw materials (A), (B), (C) and (D)
A method of synthesizing a polyester resin by mixing together and advancing the esterification reaction at 180 to 260 ° C. for 3 to 15 hours.

The polyester resin obtained by the reaction of the raw materials (A), (B), (C) and (D) is dissolved or adjusted to an appropriate concentration with a solvent 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-
Preference is given to using 2-methylphenol and the mixture thereof gresylic acid. Others, N-methyl-2
A polar solvent such as -pyrrolidone or 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 polyester resin insulating coating used in the present invention is cresylic acid. Cresolic acid 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 the insulating coating material thus obtained is applied onto a conductor and baked to produce an insulated wire of the present invention, the use of a small amount of a metal desiccant improves the surface smoothness of the insulated wire and improves the take-up speed. It is preferable because it can be speeded up and the workability is 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 8.0% by weight, preferably 1 to 3% by weight, based on the solid content of the insulating coating.

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 reaction product of 2,4-tolylene diisocyanate with 1 mol of trimethylol ethane, 3 mol of 2,6-tolylene diisocyanate Reaction product with 1 mol of trimethylolethane, reaction product of mixed 3 mol of 2,4- and 2,6-tolylene diisocyanate with 1 mol of trimethylolpropane, mixed 2,4- and 2 Examples thereof include stabilized polyisocyanates obtained by blocking a cyclic trimer of 6,6-tolylene diisocyanate with phenol or cresol. Further, stabilized isocyanates obtained by blocking diphenylmethane-4,4'-diisocyanate with xylenol are also useful.

In addition, 0.1 to 5% by weight of phenol-formaldehyde resin, melamine-formaldehyde resin, cresol-formaldehyde resin, xylene-formaldehyde resin, epoxy resin and silicone resin can be added to further improve the appearance workability of the insulated wire. . If these resins are less than 0.1% by weight,
It is not effective 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 above is the content of the polyester insulating coating used in the present invention, and the insulated electric wire of the present invention by the insulating coating is provided by applying the above polyester insulating coating on a conductor and baking to give 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 for forming an insulating coating on the conductor may be based on a conventionally known method, for example, applying an insulating coating by a method such as a felt drawing method or a die drawing method, and continuously applying a temperature of about 350 to 550 ° C. The desired insulating film is formed by passing it through the baking furnace several times or a dozen times. The thickness of the insulating film is the film thickness specified in the standards such as JIS, NEMA or IEC.

(Effect) According to the present invention as described above, a polyester-insulated electric wire that can be soldered is economically provided.

Next, the contents of the present invention will be described more specifically with reference to Reference Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples. In the text,% is based on weight unless otherwise specified.

Reference Example 1 equipped with a stirrer, nitrogen gas introduction pipe, thermometer and cooling pipe
To a 3,000 cc four-necked flask, terephthalic acid 581 g (7.0 equivalents) ethylene glycol 279 g (9.0 equivalents) glycerin 186 g (6.0 equivalents) tetrabutyl titanate 2 g were added, mixed and stirred, and heated to 200 ° C over 8 hours. After warming, 192 g (3.0 equivalents) of trimellitic anhydride is added to this system, and the esterification reaction proceeds at 220 ° C for 3 hours. The degree of reaction was measured by the increase in viscosity, and samples were taken over time.

The end point of the reaction is that the viscosity of the resin sample is 40% in cresol.
Cresol 1614 when Z ₃ (Gardner viscometer)
Add g to make the nonvolatile content 40%, and add Nisseki Chemical Hysol # 100 to this to make a resin solution having a nonvolatile content of 35%.

Furthermore, 5% of tetrabutyl titanate was added to the resin content to obtain an insulating coating.

Reference Example 2 Dimethyl terephthalate 679g (7.0 equivalents) Trimellitic anhydride 192g (3.0 equivalents) Ethylene glycol 279g (9.0 equivalents) Glycerin 186g (6.0 equivalents) Lissajous 0.7g Other than the above components, Reference Example An insulating paint was obtained in the same manner as in 1.

Reference Example 3 Dimethyl terephthalate 679g (7.0 equivalents) Trimellitic anhydride 192g (3.0 equivalents) Propylene glycol 342g (9.0 equivalents) Glycerin 186g (6.0 equivalents) Lisage 0.7g Other than the above components, other reference examples An insulating paint was obtained in the same manner as in 1.

Reference Example 4 Dimethyl terephthalate 679g (7.0 equivalents) Trimellitic anhydride 192g (3.0 equivalents) 1,6-hexanediol 531g (9.0 equivalents) Glycerin 186g (6.0 equivalents) Lisage 0.7g Except that the above components were used, An insulating coating material was obtained in the same manner as in Reference Example 1 except for the above.

Reference Example 5 Dimethyl terephthalate 388g (4.0 equivalents) Isophthalic acid 249g (3.0 equivalents) Trimellitic anhydride 192g (3.0 equivalents) Ethylene glycol 279g (9.0 equivalents) Glycerin 184g (6.0 equivalents) Lisage 0.6g Using the above components Except for this, an insulating coating material was obtained in the same manner as in Reference Example 1.

Reference Example 6 Dimethyl terephthalate 388g (4.0 equivalents) Phthalic anhydride 222g (3.0 equivalents) Trimellitic anhydride 192g (3.0 equivalents) Ethylene glycol 279g (9.0 equivalents) Glycerin 186g (6.0 equivalents) Lisage 0.4g Using the above components Except for the above, an insulating coating material was obtained in the same manner as in Reference Example 1.

Reference Example 7 Dimethyl terephthalate 679g (7.0 equivalents) Trimellitic anhydride 192g (3.0 equivalents) Ethylene glycol 140g (4.5 equivalents) Propylene glycol 171g (4.5 equivalents) Glycerin 186g (6.0 equivalents) Resurge 0.7g Using the above ingredients Except for this, an insulating coating material was obtained in the same manner as in Reference Example 1.

Reference Example 8 Dimethyl terephthalate 679g (7.0 equivalents) Trimellitic anhydride 192g (3.0 equivalents) Ethylene glycol 140g (4.5 equivalents) 1,6-hexanediol 171g (4.5 equivalents) Glycerin 186g (6.0 equivalents) Resurge 0.7g An insulating coating material was obtained in the same manner as in Reference Example 1 except that it was used.

Reference Example 9 Dimethyl terephthalate 679g (7.0 equivalents) Trimellitic anhydride 192g (3.0 equivalents) Ethylene glycol 279g (9.0 equivalents) Trimethylolpropane 270g (6.0 equivalents) Lisage 0.7g Other than using the above components, An insulating coating material was obtained in the same manner as in Reference Example 1.

Comparative Reference Example 1 To the same apparatus as Reference Example 1, dimethyl terephthalate 776g (8.0 equivalents) isophthalic acid 166g (2.0 equivalents) ethylene glycol 251g (8.0 equivalents) glycerin 171g (5.5 equivalents) litharge 0.8g were added and mixed with stirring. The temperature is raised to 200 ° C. over 8 hours, and the condensation reaction is further advanced at 220 to 240 ° C. for 3 hours. The degree of reaction was measured by the increase in viscosity, and samples were taken over time.

At the end of the reaction, the viscosity of the resin sample was 40% Z _{2 in} cresol.
-Z ₃ (Gardner viscometer) when cresol 160
Add 2 g to make the nonvolatile content 40%, and add Nisseki Chemical Hisol # 100 to this to make a resin solution having a nonvolatile content of 35%.

Further, 5% of tetrabutyl titanate and 0.3% of zinc octenoate (zinc content 8%) was added as Zn to the resin content to obtain an insulating coating material of Comparative Reference Example.

Comparative Reference Example 2 Dimethyl terephthalate 970 g (10.0 equivalents) Ethylene glycol 186 g (6.0 equivalents) Glycerin 279 g (9.0 equivalents) Lissajous 1.0 g Comparative Reference Example 1 except that the above components were used. Got insulation paint.

Examples 1 to 11 and Comparative Examples 1 and 2 The polyester insulating coatings of Reference Examples 1 to 11 and Comparative Reference Examples 1 and 2 were applied and baked under the following conditions,
Corresponding insulated wires of the present invention and a comparative example were manufactured.

Conductor diameter: 1.00 m / m Baking furnace; Vertical baking furnace with an effective furnace length of 2.5 m Baking temperature: 500 ° C (maximum temperature) Drawing method: Die method Coating frequency: 6 times Coating thickness: 0.035 to 0.04 m / m test The method was performed according to the JIS C 3003-1984 enamel copper wire and enamel aluminum wire test method. The test results are shown in Table 1 below.

As is clear from the results shown in Table 1 below, the insulated wire of the present invention has characteristics equivalent to or higher than those of conventional polyester insulated wires, and
It is clear that it has excellent solder releasability.

Continuation of front page (56) Reference JP-A-52-110736 (JP, A) JP-A-61-254674 (JP, A) JP-B 37-4078 (JP, B1) JP-B 59-17486 (JP) , B2) JP-B-57-4044 (JP, B2)

Claims (2)

[Claims] 1. At least one divalent carboxylic acid selected from the group consisting of (A) terephthalic acid, isophthalic acid, lower alkyl esters thereof, phthalic acid and anhydrides thereof.
Equivalent%, (B) trimellitic acid and / or its trihydric carboxylic acid 3 to 30 equivalent%, and (C) at least one selected from ethylene glycol, propylene glycol and 1,6-hexanediol. 20 to 50 equivalent% of the seed dihydric alcohol, and (D) glycerin and / or 1,
Trivalent aliphatic alcohol which is 1,1-trimethylolpropane 5 to 40 equivalent% [however, the total of (A) to (D) is
100 equivalent%] and (A) and (B) are 30 in total.
To 50 equivalent%, and the sum of (C) and (D) is 50 to
An insulated wire capable of being soldered, characterized in that a polyester insulating coating containing a polyester resin and an alkyl titanate obtained by reacting so as to be 70 equivalent% is applied and baked on a conductor. 2. The solderable insulated wire according to claim 1, wherein the insulating paint further contains a phenol-formaldehyde resin and / or a xylene-formaldehyde resin.