JPH05247374A - Lubricating paint and self-lubricating insulated wire produced therewith - Google Patents

Abstract

PURPOSE:To provide a paint compounded with fine powder of a fluororesin, resistant to the agglomeration or flotation of the fluororesin powder and having excellent dispersibility and storage stability. CONSTITUTION:Fine powder of a fluororesin is dispersed in an alcohol such as ethanol and the dispersion is compounded to a paint composed of e.g. polyester, polyamide imide and polyester imide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating paint having excellent lubricity and storage stability, and a self-lubricating insulated wire using this lubricating paint.

[0002]

2. Description of the Related Art Heretofore, as a self-lubricating insulated wire of this type, a fine powder of fluororesin such as polytetrafluoroethylene has been added to and dispersed in an insulating coating such as polyester or polyamide-imide to directly or directly apply a lubricating coating on the conductor. A self-lubricating insulated electric wire is known in which a lubricating coating is formed by coating and baking the outermost layer through another insulating material.

This self-lubricating insulated wire exhibits excellent surface lubricity, but the storage stability of the lubricating paint in which the fluororesin fine powder is dispersed is poor, and the fluororesin fine powder aggregates in the paint or sometimes floats and separates. There was something to do.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to obtain a fluororesin fine powder-dispersed lubricating paint having good storage stability, without the fluororesin fine powder being aggregated or floating-separated. is there.

[0005]

This problem can be solved by dispersing fine particles of fluororesin in alcohol to form a dispersion, and blending the dispersion with a coating material.

The present invention will be described in detail below. The fluororesin fine powder used in the present invention includes polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkylvinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene.・
Fluorine resin such as ethylene copolymer, chlorotrifluoroethylene / ethylene copolymer, polyvinylidene fluoride, polyvinyl fluoride, etc. has an average particle size of 10 μm.
The following fine powders are used. If the average particle size exceeds 10 μm, the fine powder tends to be clogged in the coating die during coating, the workability deteriorates, and the finished surface becomes defective.

As the alcohol used in the present invention, all alcohols containing an OH group in the molecule are used, but those having a boiling point in the range of 70 to 210 ° C. are preferably used, for example, ethanol, 2- Propanol,
2-butanol, isobutyl alcohol, tetrabutyl alcohol, 1-pentanol, 2-pentanol, 3
-Pentanol, 2-methyl-1-butanol, isopentyl alcohol, tetrapentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-
Hexanol, 2-methyl-1-pentanol, 4-
Methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, 1-nonanol, garbitol , Furfuryl alcohol, benzyl alcohol, cyclopentanol, cyclohexanol, allyl alcohol, propalpagyl alcohol and the like.

In the present invention, the alcohol is used as a dispersion medium, and the fluororesin fine powder is dispersed in the alcohol to form a dispersion. This dispersion is prepared so that the amount of the fluororesin fine powder is 10 to 80% by weight of the total amount. If the amount of alcohol exceeds 90% by weight, the compatibility with the solvent in the paint becomes poor and the paint becomes unstable,
If it is less than 20% by weight, the fluororesin fine powder tends to agglomerate. For producing the dispersion, a method of adding a required amount of fluororesin fine powder to alcohol and stirring with a high speed stirrer such as a homogenizer for about 2 to 30 minutes can be employed. In such a dispersion, the fluororesin fine powder is uniformly and stably dispersed in alcohol. When an organic solvent other than alcohol is used as the dispersion medium, a uniform dispersed state cannot be obtained.

The fluororesin fine powder dispersion thus obtained is blended with a paint to form the lubricating paint of the present invention. As the paint used here, the usual insulating paint for insulated wires is used as it is, and for example, polyamide imide, polyester, polyester imide, polyimide,
Polyurethane, polyvinyl formal, polyhydantoin, polyester amide imide, polyester amide,
Insulating paints made of polyamide, polyvinyl butyral, epoxy, etc. can be mentioned.

The amount of the fluororesin fine powder dispersion added to the coating composition is such that the solid content (fluororesin fine powder) of the dispersion is 0.1 to 30 parts by weight based on 100 parts by weight of the resin content of the coating composition. Stipulated in. If the solid content is less than 0.1 parts by weight, the lubricity of the resulting lubricous electric wire will be insufficient, and if it exceeds 30 parts by weight, the dispersion in the paint will not be carried out well and precipitation or aggregation will occur.

The fluororesin fine powder dispersion is compounded into the coating material by adding a predetermined amount of the above dispersion to the coating material and stirring with a conventional stirrer for about 0.5 to 24 hours.

In such a lubricating paint, the dispersibility of the fluororesin fine powder in the paint is improved, and the fluororesin fine powder may agglomerate or separate and float even after being left for a long time. The storage stability is good.

The self-lubricating insulated wire of the present invention can be obtained by applying such a lubricating paint directly on the conductor or through the other insulating coating to the outermost layer thereof and baking it to form a lubricating layer. Other insulating coatings include polyamide imide,
Polyester, polyester imide, polyimide, polyurethane, polyvinyl formal, polyhydantoin,
A known insulating coating such as polyester amide imide, polyester amide, polyamide, polyvinyl butyral, epoxy, etc. is applied and baked.

If the thickness of the lubricating layer is sufficiently thick, the other insulating coating can be omitted. When a lubricating layer made of the above-mentioned lubricating paint is formed on the outermost layer via an insulating film, the thickness of the lubricating layer is set to about 1 to 10 μm. In addition, the film thickness of the lubricating layer when the other insulating film is omitted is 10
Approximately 100 μm.

The application and baking conditions of the above-mentioned lubricating paint may be the same as those of ordinary insulating paint.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. (Comparative Example 1) Polyamide-imide coating (Hitachi Kasei "HI
-4062-34 ") 100 g of polytetrafluoroethylene powder (Daikin Industries" L-2 ") 1.36
After adding g, the mixture was stirred with a three-one motor for 24 hours to obtain a lubricating polyamideimide coating. When this paint was left at room temperature for 3 days, polytetrafluoroethylene powder floated and separated on the upper layer of the paint.

(Comparative Example 2) 1.36 g of polytetrafluoroethylene powder (same as above) was dispersed in 6.8 g of xylene and then stirred with a homogenizer for 10 minutes, then added to 100 g of polyamide-imide coating (same as above), and three-one was added. After stirring with a motor for 24 hours, a lubricating polyamideimide coating was obtained. When this paint was left at room temperature for 3 days, the polytetrafluoroethylene powder aggregated and precipitated in the lower layer of the paint.

(Comparative Examples 3 and 4) Comparative examples 3 and 4 were carried out in the same manner as in Comparative Example 2 except that xylene was replaced by cresol and N-methyl-2-pyrrolidone. When the paint using cresol as a dispersant was left at room temperature for 3 days as in Comparative Example 2, the polytetrafluoroethylene powder aggregated and precipitated in the lower layer of the paint. Also, in the case of using N-methyl-2-pyrrolidone as the dispersant, the polytetrafluoroethylene powder floated and separated at the stage of the dispersion, but when it was blended in the paint as it was, the polytetrafluoroethylene powder was also found in the paint. It was floating and separated.

Example 1 1.36 g of polytetrafluoroethylene powder (same as above) was added to 6.8 of ethyl alcohol.
After being dispersed in 100 g, the mixture was stirred with a homogenizer for 10 minutes, added to 100 g of polyamideimide coating (same as above), and stirred with a three-one motor for 24 hours to obtain a lubricating polyamideimide coating. Even when this paint was allowed to stand at room temperature for 3 days, the polytetrafluoroethylene powder was well dispersed and was not precipitated in the lower layer of the paint.

(Examples 2 to 5) The same procedure as in Example 1 was repeated except that isopropyl alcohol, isobutyl alcohol, 1-hexanol and carbitol were used instead of ethyl alcohol. Even when these paints were allowed to stand at room temperature for 3 days, the polytetrafluoroethylene powder was well dispersed and no precipitate was formed in the lower layer of the paint.

(Examples 6 to 7) In Example 2, instead of the polyamide-imide coating (described above), a polyester coating ("Televec E-1150-43" manufactured by Dainichi Seika) and an ester-imide coating (Nippon Schenectady Chemical Co., Ltd.) were used. "ISOMI
A lubricating paint was obtained in the same manner except that D40SH ") was used. Even when the above coating composition was allowed to stand at room temperature for 3 days, the tetrafluoroethylene powder was well dispersed and was not precipitated in the lower layer of the coating composition.

(Comparative use examples 1 to 4, practical use examples 1 to 5)
Isomid, which is a polyester imide paint of Solar Schenecta Day Chemical Co., was applied onto a copper wire having an outer diameter of 1.0 mm, and baking was repeated 6 times.
Application and baking of the coating materials of Example 4 and Examples 1 to 5 were repeated twice to obtain a self-lubricating polyamideimide overcoated polyesterimide insulated wire.

(Examples of Use 6 to 7) ISOMID 40SH, which is a polyester imide paint manufactured by Nippon Schenecta Day Chemical Co., was applied onto a copper wire having an outer diameter of 1.0 mm, and baking was repeated 6 times. The coatings 6 to 7 were applied and baked twice to obtain a self-lubricating polyamideimide overcoated polyesterimide insulated electric wire.

The characteristics of the paint and the self-lubricating insulated wire obtained as described above are shown in Tables 1 and 2. Further, the coating and baking of the paint were carried out at a furnace temperature of 400 ° C. and a linear velocity of 20 m / min using a furnace of a furnace length of 8 m. Further, the characteristics of the obtained self-lubricating insulated electric wire are JIS C 3003 or NEMA MW-10 except static friction coefficient.
00 was measured. The static friction coefficient is a measurement of the static friction coefficient between self-lubricating insulated wires. The method of measurement is to install two self-lubricating insulated wires in parallel to a metal block and place them on a flat surface. The minimum load required to move the former metal block along two self-lubricating electric wires on a plane is placed on the parallel self-lubricating insulated electric wires so that each wire makes a right angle. It is divided by the load of the block.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

As described above, the lubricating coating composition of the present invention comprises a dispersion of fluororesin fine powder dispersed in alcohol, and therefore the fluororesin fine powder aggregates in the coating composition. It has excellent storage stability and exhibits excellent lubricity without being subjected to freezing or floating separation. In addition, the self-lubricating insulated wire of the present invention,
Since the above lubricant coating is applied and baked, the fluororesin fine powder is uniformly dispersed in the lubricating layer,
It exhibits excellent surface lubricity.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruo Yamazawa 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Line Co., Ltd.

Claims (2)

[Claims] 1. A lubricating paint prepared by blending a dispersion obtained by dispersing fine particles of a fluororesin in alcohol with a paint. 2. A self-lubricating insulated wire obtained by applying the lubricating coating composition according to claim 1 to the outermost layer and baking it.