JP2758092B2 - Self-lubricating insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-lubricating insulated wire in which an insulating layer itself formed on a conductor has good lubricity.

[0002]

2. Description of the Related Art Generally, insulated wires are liable to damage or break the insulation layer due to a load applied during manufacturing and processing. However, in order to reduce the load, the slip resistance of the surface of the insulated wire is increased to reduce the frictional resistance. It is effective to do so. For this reason, as a means for improving the slipperiness, a method of applying a lubricating oil, a paraffin, a wax or the like to the surface of the insulating layer, or providing an overcoat layer made of a resin having a low coefficient of friction such as nylon or polyethylene is conventionally used as a means for improving the slipperiness. A method, a method of including the lubricating component in the insulating layer, and the like have been adopted.

However, in recent years, there has been a tendency to increase the winding speed and occupancy, that is, the amount of electric wires to be arranged in a certain space, for the purpose of speeding up the entire manufacturing and processing steps and improving space efficiency. Accordingly, the load applied to the insulated wire is inevitably increased, and the above-mentioned method can no longer cope with severe conditions in recent years.

Therefore, as an alternative to the above method, polyethylene powder having an average particle diameter of 10 μm or less in the insulating layer,
Means for blending fine lubricating resin powder such as polypropylene powder and ethylene tetrafluoride powder (Japanese Patent Publication No. 2-199710, Japanese Patent Publication No. 63-59482, etc.), and adding a linear alkyl group to the terminal of the molecular chain Means for providing an insulating layer mainly composed of a modified polyamideimide containing a polyamideimide resin (Japanese Patent Publication No. Sho 63-51193) and the like have been proposed.

[0005]

However, in the above-mentioned means of blending the lubricating resin fine powder into the insulating layer, the fine powder is difficult to be uniformly dispersed in the insulating paint used for forming the insulating layer, and the There is a problem that the stability is deteriorated, the mechanical and physical properties of the insulating layer are reduced, and the appearance is easily reduced due to the uneven dispersion of the fine powder.
Further, in the means for providing an insulating layer containing a polyamide-imide resin as a main component, the degree of polymerization of the modified polyamide-imide cannot be increased, so that the flexibility of the insulating layer becomes insufficient and the structure of the modified polyamide-imide is reduced. Therefore, the effect of improving the smoothness of the surface of the insulating layer is naturally limited, and it is difficult to sufficiently cope with a case where the winding speed and the occupancy are further increased.

In view of the above situation, the present invention, provided with a polyamide-imide insulating layer, has extremely high slipperiness of the insulating layer itself. Hardly cause disconnection, and can sufficiently cope with recent demands for speeding up the entire manufacturing and processing steps and improving space efficiency. In addition, heat resistance and flexibility of the insulating layer, stability, processing resistance, It is an object of the present invention to provide a self-lubricating insulated wire having excellent appearance and good stability of an insulating paint used for forming the insulating layer.

[0007]

The self-lubricating insulated wire according to the present invention comprises, as a means for achieving the above object, an insulating layer mainly composed of a polyamideimide resin on a conductor directly or via a base insulating layer. The polyamideimide resin formed is a trivalent or more carboxylic anhydride, a reactive slip compound containing at least two reactive groups capable of reacting with an isocyanate group and a linear alkyl group having 17 or more carbon atoms. And a polymer molecule in the form of a graft polymer comprising a reaction product with a diisocyanate compound and having a plurality of lubricating groups consisting of the above-mentioned straight-chain alkyl group bonded to a plurality of positions of the main chain of the polyamideimide as side chains at the terminal side. Is adopted.

According to a second aspect of the present invention, there is provided the self-lubricating insulated wire according to the first aspect, wherein the polyamideimide resin comprises a trivalent or more polyvalent carboxylic acid anhydride and a polyvalent carboxylic acid anhydride. A reaction product of 0.03 to 0.6 moles of the reactive slip compound with respect to the mole, and a diisocyanate compound substantially equimolar to both the polycarboxylic anhydride and the reactive slip compound. Is adopted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyamide-imide resin, which is the main component of the insulating layer in the insulated wire of the present invention, has a linear alkyl group on the terminal side as a side chain at a plurality of positions in the main chain of the polyamide-imide as described above. It is in the form of a graft polymer with lubricating groups attached, and these side chains provide the insulating layer with excellent self-lubricating properties. However, in such a polyamide-imide resin, it is possible to introduce a large number of such side chains having a straight-chain alkyl group into one molecule during the synthesis thereof in one molecule, so that the surface lubricity of the formed insulating layer is reduced. Can be significantly increased, and there is no restriction on the degree of polymerization due to the introduction of a lubricating component due to the mechanism of the synthesis reaction, so that an insulating film having a high degree of polymerization and excellent flexibility can be formed. In addition, since it is not necessary to mix special solid fine particles and the like in the insulating paint mainly composed of the polyamide-imide resin, the stability is naturally good, and the formed insulating layer is uniform and the polyamide-imide resin has an inherent property. It has excellent heat resistance and processing resistance.

On the other hand, in a polyamideimide resin having a lubricating group such as a linear alkyl group introduced at a molecular terminal,
Since the number of parts that contribute to lubrication is limited to two per molecule, the surface lubricity of the insulating layer cannot be increased to a certain degree or more, and the polymer molecule ends when a lubricating group is added to the molecular end in polymer synthesis. Since the polymerization reaction is stopped, the degree of polymerization does not increase, and the flexibility of the insulating layer formed using the polymerization becomes insufficient as described above.

[0011] The polyamideimide resin in the form of a graft polymer used in the present invention is a carboxylic anhydride having a valency of 3 or more, at least two reactive groups capable of reacting with an isocyanate group, and a linear alkyl having 17 or more carbon atoms. And a reactive product of a reactive lubricating compound containing a group and a diisocyanate compound. That is, since the above-mentioned reactive lubricating compound has at least two reactive groups capable of reacting with an isocyanate group, a general polyamideimide obtained by a reaction between a trivalent or higher polycarboxylic acid anhydride and a diisocyanate compound is used. By the presence of the reactive slip compound in the synthesis, the reactive group reacts with the isocyanate group of the diisocyanate compound, and the moiety having the reactive group of the reactive slip compound is incorporated into the main chain of the polyamideimide. The portion containing the lubricating group constitutes a side chain branched from the main chain, and a polyamideimide polymer in the form of a graft polymer in which a lubricating group is bonded as a side chain to a plurality of positions of the main chain of the polyamideimide. Generate molecules.

Here, as the reactive lubricating compound, at least two reactive groups capable of reacting with an isocyanate group are one or both of a carboxyl group and a hydroxyl group in order to maintain the properties of the polyamideimide. Those are preferred. That is, in the synthesis of polyamideimide,
The carboxyl group forms an amide bond and the hydroxyl group forms a urethane bond by the reaction of the diisocyanate compound with the isocyanate group. The linear alkyl group in the reactive lubricating compound needs to have 17 or more carbon atoms in order to impart sufficient lubrication to the polyamideimide resin finally synthesized.

The reactive lubricating compound is not particularly limited, but may be a polyvalent compound having three or more reactive groups capable of reacting with an isocyanate group, and a linear alkyl group having 17 or more carbon atoms. And a compound having an isocyanate group (hereinafter, referred to as a linear alkyl group-containing isocyanate compound) are more preferable because of their ease of synthesis. That is, the linear alkyl group-containing isocyanate compound and the polyvalent compound may be reacted at a molar ratio such that at least two reactive groups remain.

Examples of the polyvalent compound having three or more reactive groups capable of reacting with an isocyanate group, which is one of the raw material components used in the synthesis of the reactive lubricating compound, include:
Glycerin, trimethylolpropane, pentaerythritol, trimellitic acid, pyromellitic acid, 3.3 '
Compounds having three or more carboxyl groups and / or hydroxyl groups in the molecule, such as 4,4′-diphenylethertetracarboxylic acid and naphthalenetetracarboxylic acid, may be mentioned.

The linear alkyl group-containing isocyanate compound, which is the other raw material component used in the synthesis of the reactive lubricating compound, is not particularly limited, but has an isocyanate group at one end and a carbon atom at the other end. Those composed of linear alkyl groups having the number of 17 or more are preferred. Thus, in order to obtain such a linear alkyl group-containing isocyanate compound, for example, stearic acid, montanic acid, higher fatty acids such as docosanoic acid, aliphatic acids having a carboxyl group or a hydroxyl group at one end such as higher aliphatic alcohols, etc. What is necessary is just to make an equimolar reaction of a compound and a diisocyanate compound.

The synthesis of the reactive lubricating compound is as described above,
A polyvalent compound having three or more reactive groups capable of reacting with an isocyanate group is reacted with a linear alkyl group-containing isocyanate compound so as to leave at least two of the former reactive groups. For example, when the latter compound is a reaction product of an aliphatic monocarboxylic acid and a diisocyanate compound, the reaction product has an isocyanate group at one of both ends by combining both raw material components via one amide bond. Since it has a structure having a straight-chain alkyl group on the other side,
When the former compound has three reactive groups, it is reacted with 2 moles per mole of the former compound, and when it has four reactive groups, it is reacted with an equimolar amount. A reactive lubricating compound having a structure having a linear alkyl group at both terminals or at one terminal with two reactive groups remaining is obtained.

The amount of the reactive lubricating compound to be used in the synthesis of the polyamideimide is preferably in the range of 0.03 to 0.6 mol per mol of the trivalent or higher polycarboxylic acid anhydride. If the amount is too large, a sufficient effect of improving lubricity cannot be obtained, and if the amount is too large, the heat resistance of the insulated wire decreases. Then
In order to synthesize polyamideimide, 110-140 ° C in a suitable solvent such as N-methyl-2-pyrrolidone.
Under a certain degree of heating, both the polycarboxylic acid anhydride and the reactive lubricating compound may be reacted with a substantially equimolar diisocyanate compound.

Examples of the trivalent or higher polycarboxylic anhydride used in the synthesis of polyamideimide include trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride and the like. In particular, trimellitic anhydride Is preferred.

Examples of the diisocyanate compound include ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, diphenylmethane-2.4'-diisocyanate, and diphenylmethane-4.4 '. -Diisocyanate, diphenyl ether-4.4'-diisocyanate, naphthalene-1.4
-Diisocyanate, naphthalene-1.5-diisocyanate, etc., and other than these, any of various diisocyanate compounds known as raw materials for synthesizing polyamideimide can be used.

In order to manufacture an insulated wire, a solution containing the polyamideimide after the above-described synthesis reaction itself, or various additives such as a resin component, a coloring agent, and a filler, if necessary, are added to the solution. As a coating that does not impair the performance as a coating used as an insulating paint, this paint is applied directly on a conductor such as soft copper wire or through a base insulating layer formed in advance on the conductor, and applied and baked. What is necessary is just to form the slippery insulating layer of required thickness. Further, as the base insulating layer, an insulating layer made of various heat-resistant resins such as polyester, polyesterimide, polyamideimide, and polyimide can be employed.

[0021]

EXAMPLES Examples of the present invention will be described in detail below in comparison with comparative examples, but the present invention is not limited to these examples.

Example 1 Diphenylmethane-4 was placed in a four-liter four-necked flask.
-250 g of 4'-diisocyanate and 480 montanic acid
g and 2,500 g of N-methyl-2-pyrrolidone, reacted at 100 ° C. for 2 hours, cooled to 60 ° C., and gradually added with 130 g of pyromellitic acid, and the temperature was raised to 100 ° C. Then, the mixture was allowed to react for 5 hours. After the temperature was lowered until the liquid temperature reached room temperature, crystallization was performed with dimethylformamide, and the crystals were collected by filtration to obtain two carboxyl groups in the middle of the molecule. There was obtained a reactive lubricating compound A in which both terminal sides were composed of a linear alkyl group having 28 carbon atoms.

Next, 3.2 moles of trimellitic anhydride and diphenylmethane-4.
It contains 3.4 mol of 4'-diisocyanate, 0.096 mol of reactive lubricating compound A and 1,760 g of N-methyl-2-pyrrolidone, and is heated at 100 ° C. for 2 hours and then at 1 ° C.
The reaction was carried out at 25 ° C. for 1.5 hours and further at 150 ° C. for 1 hour to synthesize polyamideimide. Then, the self-lubricating insulated wire was manufactured by using the reaction solution after the synthesis as an insulating coating material, and repeatedly applying and baking it to a 1.0 mm soft copper wire to form a lubricating insulating layer.

Example 2 Diphenylmethane-4 in the synthesis of polyamideimide
-A self-lubricating insulated wire was manufactured in the same manner as in Example 1, except that the amount of 4'-diisocyanate used was changed to 3.9 mol and the amount of reactive lubricating compound A was changed to 0.64 mol. .

Example 3 Diphenylmethane-4 in the synthesis of polyamideimide
-A self-lubricating insulated wire was manufactured in the same manner as in Example 1, except that the amount of 4'-diisocyanate used was changed to 4.5 mol and the amount of the reactive slip compound A was changed to 1.28 mol. .

Example 4 The procedure of Example 1 was repeated, except that 284 g of stearic acid was used instead of montanic acid. The reactive lubricating compound B constituted by was obtained. And
0.64 mol of the reactive lubricating compound B was used in place of the reactive lubricating compound A, and diphenylmethane-4 ·
A self-lubricating insulated wire was manufactured in the same manner as in Example 1, except that the amount of 4′-diisocyanate was changed to 3.9 mol to synthesize a polyamideimide.

Example 5 In the same manner as in Example 1 except that 70 g of trimellitic acid was used instead of pyromellitic acid, the molecule had two carboxyl groups at one terminal and the other terminal had 28 carbon atoms. A reactive lubricating compound C comprising a linear alkyl group was obtained. Then, 0.64 mol of the reactive lubricating compound C was used instead of the reactive lubricating compound A, and the amount of diphenylmethane-4,4'-diisocyanate used was 3.9.
A self-lubricating insulated wire was manufactured in the same manner as in Example 1, except that the mole was changed to a polyamideimide.

Example 6 Trimethylolpropane 121 in place of pyromellitic acid
g, and without using diphenylmethane-4,4'-diisocyanate, except that montanic acid and trimethylolpropane were directly transesterified to give one end of the molecule in the same manner as in Example 1. A reactive lubricating compound D having two carboxyl groups and having the opposite terminal side constituted by a linear alkyl group having 28 carbon atoms was obtained. Then, 0.64 mol of the reactive lubricating compound D was used instead of the reactive lubricating compound A, and diphenylmethane-4 ·
A self-lubricating insulated wire was manufactured in the same manner as in Example 1, except that the amount of 4′-diisocyanate was changed to 3.9 mol to synthesize a polyamideimide.

Example 7 A commercially available polyesterimide insulating paint (ISOMID manufactured by Schenectady Co., Ltd.) was previously applied to a 0.20 mm soft copper wire.
40ST) is repeatedly applied and baked a plurality of times to form a base insulating layer, and the synthesized polyamideimide insulating paint is repeatedly applied and baked on the base insulating layer a plurality of times to form a slip insulating layer. A self-lubricating insulated wire was manufactured in the same manner as in Example 1.

Comparative Example 1 Diphenylmethane-4 was used without using the reactive lubricating compound A.
-An insulated wire was manufactured in the same manner as in Example 1 except that the amount of 4'-diisocyanate was changed to 3.2 mol to synthesize a polyamideimide.

Comparative Example 2 3.2 mol of trimellitic anhydride, 3.9 mol of diphenylmethane-4,4'-diisocyanate, 6.3 mol of montanic acid, and N-
80 ℃ containing 1,760 g of methyl-2-pyrrolidone
After heating for 2 hours at 170 ° C., the temperature was raised to 170 ° C. over 5 hours, and the reaction was carried out at this temperature for 2 hours to synthesize a polyamideimide having a lubricating group consisting of a linear alkyl group at a molecular terminal. Then, an insulated wire was manufactured in the same manner as in Example 1 using the reaction solution after the synthesis as an insulating paint.

Table 1 shows the characteristics of the insulated wires obtained in the above Examples and Comparative Examples. The softening resistance in the table is based on JI
It was measured under the conditions of SC 3003 12 (2).

[0033]

[Table 1]

[0034]

According to the first aspect of the present invention, as a material of the insulating layer, a slip group having a linear alkyl group having 17 or more carbon atoms at the terminal side is bonded as a side chain to a plurality of positions of the main chain of the polyamideimide polymer. The use of a polyamide-imide resin in the form of a specific graft polymer, the insulating layer itself has extremely high lubricity, and even if the winding speed and the occupancy are very large, the insulating layer is unlikely to be damaged or disconnected. In addition to being able to sufficiently cope with the demand for speeding up the entire manufacturing and processing steps and improving space efficiency, the insulating layer is excellent in heat resistance, flexibility, stability, processing resistance, appearance, and the insulating layer A self-lubricating insulated wire can be provided which also has good stability of the insulating paint used for forming the wire.

According to the second aspect of the present invention, as the above-mentioned self-lubricating insulated wire, there is provided a wire having particularly excellent surface smoothness of the insulating layer and good heat resistance.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Tai 2-9-1-1, Inaji, Amagasaki-shi, Hyogo Pref. Technical Department, No. 1 Electric Works Co., Ltd. (72) Inventor Junichiro Watanabe 2-9-1-1, Inaji, Amagasaki-shi, Hyogo Technical Department, Daiichi Denko Co., Ltd. (56) References JP-A-56-106308 (JP, A) JP-A-58-26409 (JP, A) JP-A-3-115478 (JP, A)

Claims (2)

(57) [Claims] 1. A dielectric layer mainly composed of polyamide-imide resin directly or via an underlying insulating layer on the conductor is formed, the polyamide-imide resin, a trivalent or higher carboxylic anhydride
An acid and at least two of the
Has a reactive group and a linear alkyl group having 17 or more carbon atoms
Reaction of reactive lubricating compound with diisocyanate compound
And side chains at several places in the main chain of polyamideimide
As a plurality of lubricating ends comprising the linear alkyl group
A self-lubricating insulated wire, characterized in that it is a polymer molecule in the form of a graft polymer having attached groups . 2. The polyamide-imide resin has a valence of 3 or more.
A polycarboxylic anhydride and a polycarboxylic anhydride
0.03-0.6 mole of reactive slip compound per mole
And these polyvalent carboxylic anhydrides and reactive lubricating compounds
A substantially equimolar amount of diisocyanate compound to both
2. The self-lubricating insulated wire according to claim 1, comprising a reaction product with a product .