JPS6258086B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for melt-applying a lubricant that is solid at room temperature to an insulated wire. Furthermore, the present invention relates to a method of manufacturing a lubricant-insulated wire with excellent windability. In recent years, electronics manufacturers that use enamelled wire have begun to use high-speed automatic wire winding machines in order to speed up the manufacturing process of devices.
However, in this case, although it appears that the processing cost of the equipment has been significantly reduced by speeding up the process, in reality, the enamelled wire is subjected to friction during winding, and the insulating layer is mechanically damaged. For this reason, after being incorporated into a device, electrical short circuits (hereinafter referred to as "rare shorts") occur between wound enameled wires that are adjacent to each other, resulting in a major problem in which the loss rate increases significantly. ing. In order to solve this problem, attempts have been made to impart lubricity to the enameled wire to reduce mechanical damage. This applies not only to automatic winding machines but also to manual winding. For example, when inserting enameled wire into a narrow slot in a motor, enamelled wire with good sliding properties is desired in order to improve the efficiency of manual winding. Since the enameled wire itself has poor lubricity, there is poor slippage between the enamelled wires, between the enameled wires and the winding machine, between the enameled wires and the equipment, and the insulating layer is damaged and work efficiency is reduced. For this reason, a method has been adopted in which a liquid lubricant such as liquid paraffin or refrigerating machine oil is applied onto the enameled wire. However, this method has the disadvantage of poor lubricity and slipperiness, resulting in poor wire handling by hand and poor alignment of transformers, coils, etc. during winding. Rare shorts are increasing due to the expansion of the application of inserter methods that improve space factor. Also, since this method uses a liquid lubricant, not only is it easy for dust to adhere to the wire, but it can also cause the wire to come loose after winding the coil, and have a negative impact on the adhesive strength of the adhesive tape used to secure the end. Another drawback is that the tape tends to peel off easily. In order to solve this problem, electrical manufacturers that wind coils sometimes use a method of passing the wire over lumps of solid paraffin and rubbing the solid paraffin onto the wire surface, but the amount of coating is uneven and is generally overused. There are drawbacks such as the electric wires quickly getting eaten into the solid paraffin, requiring replacement each time, and the need to repeat the process of melting, solidifying and regenerating frequently for regeneration, and reduced work efficiency. There is a strong demand for electric wire manufacturers to perform lubrication treatment according to the purpose and size, and to change the type and amount of lubricant depending on the purpose, size, etc. In response to this, electric wire manufacturers have no choice but to solve the problem by dissolving about 1% solid paraffin in a solvent such as benzine xylene and applying it to the surface of the electric wire, or heating and drying it after application. However, in this method, since most of the solvent is solvent, a large amount of wasted solvent is consumed, exhaust equipment is required for hygiene and safety reasons, and equipment for removing the emitted solvent by combustion etc. is required as a pollution control measure. There is a risk of fire as it uses a solvent with a low flash point. Moreover, when performing heat drying, a heating furnace is required. Next, in terms of characteristics, when the solvent comes into contact with the wire surface, depending on the wire type, crazing occurs and the wire loses its commercial value, so the applicable types are limited, and the lubricant solution has a very low concentration. Because of the viscosity, it is not possible to control the thickness of the deposited film, so the only option is to allow the wire to adhere as it passes through the solution. Furthermore, solid paraffin has poor solubility in solvents, and there are major restrictions on the type and concentration of solvents.
Looking at solid organic lubricants other than solid paraffin, most of them are poorly soluble or insoluble in solvents, and even if they do dissolve, the concentration is low. Therefore, even if a desired solid organic lubricant is used, there are restrictions in that it cannot be used because it does not dissolve in the solvent, or even if it is dissolved, it can only be used at a low concentration. As mentioned above, the solution method has many disadvantages in terms of resource saving, pollution control, environmental health, and safety, and currently there are many restrictions in terms of the range of applicable properties and the range of applicable lubricants. However, the current situation is that we have no choice but to manufacture products while addressing contradictory points in order to meet the demands of consumers. As a result of intensive research into solving these problems, the inventors of the present invention discovered that they could heat-melt an organic lubricant that is solid at room temperature and apply it onto the enameled wire without using a solvent, then homogenize the lubricant under heat and insulate it. They found a way to obtain electric wire. In other words, a fixed amount of molten lubricant is supplied to the enamelled wire using a roller, etc., and then the lubricant is passed through a heated homogenizing section to distribute the lubricant around the outer circumference of the enameled wire when hot, thereby improving the slipperiness. We have successfully succeeded in providing enamelled wire with good quality over a long period of time without any change in characteristics, and economically, under resource-saving, energy-saving, and low-pollution conditions. In the present invention, since an organic lubricant that is solid at room temperature is used, it has better slipperiness than when using a liquid lubricant, and there is no adhesion of dust to the electric wire, and there is no adverse effect on the adhesive strength of the adhesive tape. Problems with liquid lubricants can be solved. In addition, in the present invention, an insulated wire with lubricity equivalent to or better than the solution method can be obtained, and since no solvent is used, no solvent is consumed and resources are saved, and there is no need for exhaust equipment for environmental health and safety.
There is no need for removal equipment such as combustion of discharged solvents as a pollution control measure, and there is no need to worry about fires caused by low flash point solvents.
Also, of course, a heating furnace for drying the solvent is not required. Furthermore, since there is no need to worry about crazing caused by solvents, there are no restrictions on the types of products to which it can be applied. Also, since it is a 100% lubricant, the thickness of the deposited film can be changed freely by controlling viscosity, temperature, amount of application, amount of squeezing, etc. Furthermore, since it is heated and melted, it has the advantage that lubricants that are poorly soluble or insoluble in solvents that cannot be used in the solution method can be used. When applying a lubricant that is solid at room temperature to an enameled wire, etc., the enameled wire or the like is directly immersed in the lubricant that is in a molten state. A so-called dobu-zuke method is also considered, but in this dobu-zuke method, a line with a temperature lower than the melting point of the lubricant passes through the melt, so the temperature of the melt near the line decreases, the viscosity increases, and the coating amount decreases. If the lubricant becomes excessive or excessive, the lubricant may solidify on the wire. in this case,
The amount of lubricant applied is not constant (the amount applied and adhered changes as the temperature of the wire changes), and it is impossible to spread the applied lubricant thinly and evenly around the outer circumference of the wire. If the wire is curly or thin, the lubricant applied unevenly will solidify, causing uneven tension when passing through the guide rollers, making it difficult to wind onto the reel, and causing wire elongation. ,
A disconnection may occur. In this sense, the dobu-zuke method cannot be said to be completely unusable, but its applicability is limited, and it cannot be said to be a good method. If the lubricant applied by the above-mentioned dripping method is homogenized using felt, etc. in the heated homogenizing section,
Although the problem is improved, if the application continues for a long time, the excessively supplied lubricant will gradually accumulate on the equalizing part (felt, etc.), and although it is better than the case without the equalizing part, the above-mentioned However, it is not possible to completely eliminate the problems such as poor winding and wire breakage. In order to solve the above-mentioned problems, the inventors conducted intensive studies and found that when applying a solid lubricant, it is a molten liquid with a temperature higher than the melting point, and the amount of application is arbitrarily controlled using a rotating roller. A lubricant consisting of a heating plate (Fig. 1, 5 and 5') and felt, etc. (Fig. 1, 6 and 6') in which the temperature can be set arbitrarily by embedding a (solid) lubricant immediately after application. By providing a part (hereinafter abbreviated as a heating uniform part) in which the lubricant is uniformly distributed around the entire circumference of the enameled wire, a useful method for applying a room-temperature solid lubricant has been achieved. The heating equalization section is designed so that the wire temperature of the enameled wire is
In the summer, the temperature is 30-50℃, which is relatively close to the melting point of the lubricant, but in the winter, when it is cooled by the outside air, the temperature drops to 10-30℃, much lower than the melting point of solid lubricants, so it is a molten lubricant applied with a roller. However, this is important because there is a concern that it will harden and localize at the lower part of the enameled wire (ie, on the surface where the wire and roller contact). Therefore, it is necessary to provide the heating uniformity section immediately after the application roller. It is also desirable to use a flexible felt that can adhere well to the wire in order to distribute the lubricant uniformly around the wire. Describing this in detail in the drawings, a molten liquid 2 is held in a container 1 having a heating function, and a roller 3 with or without a heating function is installed in this container. This roller is rotated to bring the required amount of melt onto the roller surface, directing the line 4 to be applied in close contact onto the roller and applying the required amount of melt. The coated wire 4 is continuously guided to a homogenizing section 6, 6' sandwiched between heating plates 5, 5', and the melt is spread around the outer circumference under heating. According to this method, the amount of coating can be maintained at the required constant level by appropriately changing the number of rotations of the roller according to the size of the line and the speed of the line. By passing through the coating section, it is possible to effectively achieve uniform throwing power. The amount of application is determined by the roller section, and only uniformization is performed in the equalizing section, so even if it is operated for a long time, excess lubricant will not accumulate in the equalizing section, causing poor winding, wire breakage, etc. Methods for supplying the molten lubricant of the present invention include a groove roller method, a wiper roller method, and a method of sucking up the heated and melted lubricant with felt, etc.; Although it is possible to supply a fixed amount by appropriately combining sizes, etc., there are concerns about stable fixed supply over a long period of time. This is because the amount of coating varies due to variations in the contact pressure of the line to the felt, and the felt deteriorates due to heating, resulting in variations in the amount of wicking. This is also because the size and shape of the felt must be changed in response to changes in line size and line speed. Considering the above, the roller method is preferable in order to stably supply a fixed amount. This is because the amount of coating can be controlled arbitrarily by changing the rotation speed according to the size and speed of the line. Further, there is virtually no possibility of changes in the material of the rollers, and stable supply is possible for a long period of time. There are grooved and non-grooved rollers, and either can be used, but grooved rollers are preferred when the line size is large. If the line size is small, a roller without grooves can also be used. When using a grooved roller, the shape of the grooved roller is V-shaped, U-shaped semicircular, etc., but in order to fit into the line, it is U-shaped,
A semicircular shape is preferred, particularly a semicircular shape. If the wire is 0.1mm or less, such as from a thin wire to an extra-fine wire,
In terms of surface tension and coverage, it is possible to apply a fixed amount even without grooves. When using grooved rollers, the outer diameter of the electric wire and the diameter between the grooved rollers are preferably as close as possible if the diameter is larger than the wire diameter, but it is preferable that the diameter is about 1.2 to 3 times the wire diameter. The applicator is preferably installed in a heating tank for the lubricant melt, and in the case of grooved rollers, it is preferable that the part below the contact part (applying part) with the line of the roller is immersed in the melt. The roller itself may be heated, but if it is maintained at a constant temperature by heat from the heated melt, no special heating is required. The lubricant applied by the roller continues,
It is preferable to homogenize in a homogenizing section. The reason for uniformization is to make the coating thickness of the lubricant uniform and constant along the outer periphery of the wire. Any method may be used for the homogenization. For example, die drawing,
There are rubber apertures, felt apertures, and granular apertures in which a container is filled with granules (glass balls, sand, iron balls, etc.) and a wire is passed through the container. Of course, the above aperture methods can also be used in combination. Since the lubricant is solid at room temperature, it may solidify when it is applied to the enamelled wire or before it is squeezed after being applied. If the lubricant solidifies at this point, it will not be applied uniformly or squeezed properly, making it impossible to maintain a constant coating thickness. Therefore, it is preferable to heat the constriction section. In order to ensure uniformity, it is preferable that the temperature of the heating section is higher than the temperature of the application section. This prevents the lubricant from solidifying, so uniform application and squeezing can be achieved. More preferably, the homogenizing portion is heated felt. This is because felt drawing is an excellent method for applying thin and uniform coatings, and the felt itself is softer than the surface of the enameled wire and has the advantage of not damaging the surface of the wire. When heating felt, it is also preferable to soak a molten lubricant into the felt in advance, since felt has poor thermal conductivity. In this way,
By supplying lubricant to the felt, it can be used for both application and squeezing. If the lubricant is applied using another method and squeezed using a heated felt soaked with lubricant, even if the lubricant applied to the enameled wire is only on one side, it should be applied to the entire wire. I can do it. It is also preferable to heat the enameled wire itself beforehand. This is because if the enameled wire is heated, it is possible to prevent the molten lubricant from solidifying. Felt includes wool felt, needle felt, and a felt made by depositing nonwoven fabric, which can be used as required. When the melt is brought into contact with the coated insulated wire and the heating temperature is 70°C or higher, preferably 100°C or higher, the temperature will be quite high, 120°C or higher, so heat-resistant materials, It is necessary to have a material whose mechanical properties do not change when heat is applied (sufficient uniformity cannot be expected if it wears out). Furthermore, the painting and baking work of enameled wire is generally continuous production that lasts for a long time from days to weeks, and the lubricant application (uniformity) is melted and applied at high temperatures such as 120℃. (It can reach temperatures as high as 150℃ where the heating plate and felt come into contact), and the properties of the finished lubricated wire (good appearance, good wire handling, and sufficiently low coefficient of static friction) are good. Taking into consideration the fact that this is required over the entire length, wool felt is acceptable as a felt, but heat-resistant ones, such as polytetrafluoroethylene, such as Dupont America's Teflon felt or the like is preferred. The thickness of the felt is preferably as thin as possible in order to improve heat transfer. Preferred thickness for actual use is about 0.5 mm to 3.0 mm. The organic lubricant that is solid at room temperature used in the present invention may be any organic lubricant that melts when heated and that solidifies and exhibits lubricity after being applied to the enameled wire. Preferably, the lubricant is a compound having a long chain aliphatic group. This is because aliphatic groups have low polarity and good slipperiness. There are saturated and unsaturated aliphatic groups, but saturated is preferred because it has less polarity. The longer the alkyl group is, the more effective it can be, and it is particularly preferable that the alkyl group has 21 or more carbon atoms. It is preferable that the alkyl group has a straight chain shape as it has better slippage than a branched one. In particular, it is preferable that a part of the skeleton of the alkyl group consists of -( _CH2 ) _-o , and n≧20. Next, examples of lubricants used in the present invention will be given. Examples include hydrocarbons, fatty acids or derivatives thereof,
Examples include alcohols or derivatives thereof, fatty acid amides or derivatives thereof, polyoxyalkylenes, waxes, and greases. Of course, a mixture of these lubricants can also be used. More specific examples of lubricants are given below. It goes without saying that hydrocarbons with a large number of carbon atoms are preferred. There are saturated and unsaturated hydrocarbons, as well as linear and branched hydrocarbons, but the saturated and linear ones represented by the general formula CH ₃ (CH ₂ ) _o CH ₃ are preferable. Examples include heneicosane, docosane, tricosane, tetracosane, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, triacontane, hentriacontane, dotriacontane, tritriacontane, tetratriacontane, pentatriacontane, hexatriacontane, heptatria Contane, octatriacontane, nonatriacontane, tetracontane, low molecular weight polyethylene wax, etc. Also preferred are hydrocarbons whose main component is saturated, straight-chain hydrocarbons, which are commercially available as so-called solid paraffin. Next, we will give examples of fatty acids or their derivatives. The fatty acid preferably has an alkyl group with a large number of carbon atoms, that is, a higher fatty acid. Higher fatty acids include saturated acids and unsaturated acids, and those with straight chain alkyl groups and those with branched alkyl groups. Also, depending on the number of functional groups, monocarboxylic acid, dicarboxylic acid,
Examples include tetracarboxylic acids. Among these, the general formula
Most preferred is a linear saturated monocarboxylic acid represented by CH ₃ (CH ₂ ) _o COOH. The reason for this is that in order to exhibit a lubricating effect, it is better to have fewer polar groups. Examples of the most preferred linear saturated monocarboxylic acids among higher fatty acids include dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid,
Nonadecanoic acid, eicosanoic acid, heneicosanoic acid, docosanoic acid, tricosanoic acid, tetracosanoic acid, pentacosanoic acid, hexacosanoic acid, heptacosanoic acid, octacosanoic acid, nonacosanoic acid, triacontanoic acid, hentriacontanoic acid, dotriacontanoic acid, tetratriacontane acids, hexatriacontanoic acid, octatriacontanoic acid, etc. Acid anhydrides, esters, and fatty acid derivatives
There is salt, etc. Methyl alcohol for ester,
There are esters with various alcohols such as monohydric alcohols such as ethyl alcohol, dihydric alcohols such as ethylene glycol and diethylene glycol, trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol. For imparting lubricity, it is preferable for the aliphatic group to be long, so esters with dihydric or higher alcohols are preferable. For the same reason, esters with higher alcohols are preferable to lower alcohols. Next, examples of alcohols or their derivatives will be shown. The alcohol is preferably one having an alkyl group with a large number of carbon atoms, that is, a higher alcohol. Higher alcohols include saturated alcohols and unsaturated alcohols, and those with straight-chain alkyl groups and those with branched alkyl groups. Furthermore, there are primary alcohols, secondary alcohols, and tertiary alcohols depending on the position of the functional group, and monohydric alcohols, dihydric alcohols, trihydric alcohols, etc. depending on the number of functional groups. Among these, the linear saturated primary monohydric alcohol represented by the general formula CH ₃ (CH ₂ ) _o OH is most preferred for the reasons mentioned above. Examples include pentadecane 1-ol, hexadecane 1-ol,
All, heptadecan 1-ol, octadecane 1-ol, nonadecane 1-ol, eicosan 1-ol, heneicosanol-1, docosanol-1, tetracosanol-1, pentacosanol-1, hexacosanol-1 , heptacosanol-1, octacosanol-1, nonacosanol-1, triacontanol-1, hentriacontanol-1, dotriacontanol-1, tritriacontanol-1, tetratriacontanol-1, pentatriacontanol-1 1, heptatriacontanol-1, etc. Examples of alcohol derivatives include esters with carboxylic acids, but particularly preferred are esters with the above-mentioned higher fatty acids. Next, examples of fatty acid amides or derivatives thereof will be given.
The fatty acid amide is preferably one having an alkyl group with a large number of carbon atoms, that is, a higher fatty acid amide. Hydrocarbon groups in the skeleton of fatty acid amide include those described above for fatty acids. Preferred among fatty acid amides are those represented by the general formula CH ₃ (CH ₂ ) _o CONH ₂ . Examples include palmitylamide, stearylamide, eicosylamide, docosylamide, hexacosylamide, octacosylamide, and the like. Derivatives of fatty acid amides include those in which the hydrogen of the amide group is replaced by an alkyl group,
General formula RCONH−CH ₂ −NHCOR, RCONH−CH ₂
There is a bis fatty acid amide represented by _-CH2 -NHCOR. Next, examples will be given regarding polyoxyalkylenes. As polyoxyalkylenes, polyethylene glycol, polypropylene glycol, polyoxymethylene, etc. are known, but they have a structure with no branches in the main chain and have the general formula HO[-(CH ₂ ) _n -
O] _-oH is preferred. Examples include polyethylene glycol with various molecular weights, and among these, the preferred one is
600 or more, and particularly preferred are those with a molecular weight of 3000 or more, which have low hygroscopicity and a relatively high melting point. Next, we will give an example of waxes. Examples of waxes include microcrystalline wax, carnauba wax, beeswax, and montan wax. Hoechstwax OP (chain length
C28-32 partially saponified ester wax from montanic acid), Hoechstwax E (ester wax from montanic acid), Hoechstwax S
(Montan acid wax) is also suitable. Among the lubricants mentioned above, solid paraffin is most preferred. Solid paraffin can be easily obtained at low cost, and since it is usually commercially available in different melting point ranges, one with a desired melting point can be selected. In addition, it is chemically stable, non-toxic, and suitable for handling. The above lubricants may be used alone or in combination of two or more. In particular, it is preferable to use a mixture of two or more organic lubricants having different melting points or softening points (hereinafter referred to as melting points). When using a lubricant alone, the heating temperature must be higher than the melting point of the lubricant, but if a lubricant with a high melting point and a lubricant with a low melting point are used in combination, it can be melted at a temperature between the melting points of the two. Therefore, the heating temperature range is wide and the temperature control range of the heating device is wide.
Furthermore, the melt viscosity can be freely selected. This will be explained using solid paraffin as an example. Solid paraffin is generally commercially available in different melting point ranges, but using a mixture of paraffins with different melting points has the following advantages. For example, solid paraffin with a melting point of 54 to 56°C (hereinafter referred to as (a)) and solid paraffin with a melting point of 68 to 70°C (hereinafter referred to as (b)) are mixed in a weight ratio of 1:
When mixed with 1, this mixed paraffin (hereinafter (c)
) is because (a) acts like a solvent.
It remains liquid even at 60℃. That is, (b), which could only be used at temperatures above 70°C, can now be used at temperatures below 70°C by mixing it with (a). On the other hand (A) is 56℃
Although the above can be used, the molecular weight is lower than that of (b), and its melt viscosity is low. Therefore, if a material with a high melt viscosity is required, (b) must be used and heated to 70°C or higher. However, if (c) is used, the temperature is 60℃ or higher, and (b) is mixed with (b), which has a higher molecular weight than (b) and has the effect of increasing the melt viscosity, so it can be used at a lower temperature than (b). (stomach)
Higher viscosities can be achieved. Also, in order to increase the effect like (c), if the melting point is
Even if solid paraffin (hereinafter referred to as (d)) at about 60℃ is brought, (d) has a narrower molecular weight distribution than (c), and the viscosity decreases significantly with a slight temperature rise after melting.
It is clear that the excellent effect shown in (c) is not shown. It may be possible to do so if the temperature is slightly higher than the melting point, but this would require a very narrow temperature control range of the heating device, making it virtually impossible. The above-mentioned lubricants are just examples, and by selecting the melting points and mixing ratio of two or more lubricants having different melting points, a desired melt viscosity can be obtained in a desired temperature range. When two or more organic lubricants having different melting points are used, the heating temperature of the lubricants is preferably below the highest melting point and above the lowest melting point. Needless to say, the temperature is above the lowest melting point for heating and melting, but it is also below the highest melting point in order to increase the melt viscosity as described above, and because it is preferable to lower the heating temperature as described below. is preferred. In the present invention, the temperature at which the lubricant is applied by heating and melting is determined by the melting point of the lubricant and its melt viscosity. To lower the melt viscosity of a molten lubricant, a temperature considerably higher than the melting point is required, and to increase the melt viscosity, a temperature higher than the melting point but close to the melting point is required. If the heating temperature exceeds 150°C, the lubricant may decompose and even generate smoke, so it is preferably 150°C or lower. If heating is continued for a long time, the lubricant will gradually undergo oxidation and deterioration, so a temperature of 120°C or lower is more preferable. In addition, in consideration of safety such as burns during work, the temperature is preferably 100°C or lower, more preferably 80°C or lower. The preferred melting point range of the lubricant is therefore also determined by this. As mentioned here, due to various restrictions, it is preferable that the heating melting temperature is low, and when using a mixture of two or more lubricants with different melting points as mentioned above, it is recommended that the lubricant with a high melting point is lower than the melting point of the lubricant with a higher melting point. This is preferable because it can be used in In particular, when an appropriate amount of polyethylene glycol, etc., which has a relatively high molecular weight and a relatively low melting point, is mixed, the melting point of the mixed system is relatively low, and it is possible to give an appropriate viscosity, and it is possible to form crystals from application to homogenization. Since it is possible to delay the process, it gives favorable results. As mentioned earlier, solid paraffin is the most preferable among lubricants, but since it is available in various melting points, there is a wide range of choices when you want to lower the heating temperature or when mixing substances with different melting points. Considering these meanings, it can be said to be a preferable lubricant. There are no restrictions on the enamelled wire used in the present invention. That is, the size of the conductor, the type and structure of the insulating layer, the presence or absence of a self-bonding layer, etc. do not matter. To put it bluntly, it is used as a winding wire, especially in fields where high-speed winding is required, or where slippage is required even when done manually. Also, as mentioned earlier, unlike the solvent method, there is no worry about crazing, so it can be applied to any variety. In the present invention, there are no particular limitations on the coating state, thickness, etc. of the lubricant applied to the enameled wire. For example, even if lubricant is applied discontinuously or only on one side of the enameled wire, the lubricant applied to the enamelled wire will adhere to pass lines, guide rollers, etc. where the enameled wire is damaged during winding, and may slip. This is because the condition is improved and damage can be reduced. However, the fact that it is not applied evenly means that there are some areas that are slippery.
It goes without saying that it is preferable that the coating be applied evenly, since the possibility of damage is high, and when the wire is used manually, the wire is difficult to separate and slip. If the coating thickness is too thick, the lubricant will adhere to the pass lines, guide rollers, etc. of the winding machine, contaminating the machine or even impairing the slipperiness. Furthermore, it is not economical to use too much lubricant. Not. Also, if there is too much, the wire may become sticky or the lubricant may peel off and fall off. Therefore, it is preferable to apply it evenly and thinly. For this reason, it is preferable that the average thickness of the lubricant applied to the enameled wire is 1 micron or less. The lubricated insulated wire thus obtained has better sliding properties than an uncoated enamelled wire that is not coated with a lubricant, thus achieving the objective. However, in order to be effectively used without damage in a high-speed winding machine or the like, the coefficient of static friction of the obtained lubricant insulated wire is preferably 0.1 or less. The following examples illustrate the invention. In addition, among the characteristics of the examples, the static friction coefficient is measured by the line-to-line friction coefficient, and the measurement method is to attach two sample electric wires in parallel to a metal block, and connect them to two parallel wires placed on a flat surface. Each wire is placed at right angles to the sample electric wire, and a load is placed on the tip of the former. The wire handling property was determined by a sensory test in which the wire was picked up from a cigarette, the wire was handled by the touch, and the slipperiness was checked. The thickness of the lubricant is too thin to measure directly, so the lubricant-coated wire is immersed in toluene heated with hot water, the lubricant is washed off, the toluene is blown off, and the weight of the remaining lubricant is measured. The thickness was calculated from this. The reciprocating abrasion test was conducted using a JIS C 3003 reciprocating abrasion tester with a load of 290 g. The insulating paints used in the examples are shown below. Varnish A: Delacoat E220G (polyester insulating paint sold by Nitto Electric Industry Co., Ltd.) Varnish B: Isomitsudo LV (polyester imide insulating paint sold by Nippon Schenectaday Co., Ltd.) Varnish C: Phenoxy resin dissolved in m-cresol Self-fusing paint. Varnish D: TPU-F ₂ (Polyurethane paint made by Tokyo Tokushu Electric Wire Paint) Varnish E: Delacoat UM-303 (Polyurethane paint sold by Nitto Electric Industry Co., Ltd.) Reference example 1 Varnish A is applied to a copper wire with a diameter of 0.65 mm. An insulated wire was obtained by repeating coating and baking. Reference Example 2 Refrigerating machine oil (Suniso 4G, manufactured by Sun Petroleum Products Company, USA) was applied as a lubricant to an insulated wire baked under the same conditions as above to obtain an insulated wire. Reference Example 3 An insulated wire was obtained in exactly the same manner as in Reference Example 1, and it was placed in a melt (temperature 70°C) of solid paraffin (a mixture of 400g of melting point 54-56°C and 200g of melting point 68-70°C). I soaked it in Nidobu and let it pass. Reference Example 4 An insulated wire was obtained in the same manner as in Reference Example 1, and the insulated wire was passed through the groove of a rotating rotating roller with a U-shaped groove in a container holding a melted solid paraffin mixture, and brought into contact with the roller. Then, the melt was applied. The roller is immersed in the melt for 70% of its diameter.
Furthermore, the melt was supplied by rotating at a constant speed in the running direction of the wire and applied to the wire. The liquid temperature was 70°C, and the groove diameter of the roller was 0.80 mm. Table 1 shows the characteristics of the electric wires obtained in Reference Examples 1 to 4. Example 1 Varnish A was repeatedly applied and baked on a copper wire with a diameter of 0.65 mm, and then the inside of a roller with a U-shaped groove (groove diameter: 0.8 mm, groove depth: 0.8 mm) was coated in the same manner as in Reference Example 4. The wire was passed through the wire, and the solid lubricant melt was applied by bringing the wire into close contact with the roller, and then the wire was passed through a heating equalization section equipped with felt between the heating plates provided immediately after the roller to obtain lubricity and insulated wire. . Felt is top and bottom 2
The material used was white wool felt, and the thickness of each sheet was 3 mm. The temperature immediately before the felt line passed was 100°C. Example 2 A lubricious insulated wire was obtained in exactly the same manner as above except that the groove diameter was 1.6 mm. Example 3 A lubricious insulated wire was obtained in exactly the same manner as in Example 1 except that Teflon felt (thickness 1.5 mm, temperature between felts 100° C.) was used instead of wool felt. The characteristics of the electric wires of Examples 1 to 3 are also shown in Table 1. Reference Example 5 Varnish B was repeatedly coated and baked on a copper wire with a diameter of 0.35 mm several times to obtain an insulated wire. Example 4 An insulated wire obtained in the same manner as Reference Example 5 had a melting point of 68~
A paraffin melt at 70° C. was applied uniformly in the same manner as in Example 1. The groove of the rotating roller was U-shaped and had a groove diameter of 0.65 mm. Wool felt (thickness: 3 mm) was used for uniformity. The temperature of the application area is 80℃,
The temperature of the homogenized felt was 110°C. Example 5 Varnish A was repeatedly applied and baked several times onto a copper wire having a diameter of 1.2 mm, and then solid paraffin was melted and applied uniformly in the same manner as in Example 1. The rotating roller was U-shaped and had a diameter of 1.5 mm, the temperature at the application area was 100°C, the uniform heating felt was made of Teflon and had a thickness of 1.5 mm, and the temperature near the line where the wire ran was 120°C. Example 6 A solid lubricant was uniformly melted and applied in exactly the same manner as in Example 5. This was continued and continuous production was carried out for 5 days to obtain a lubricated electric wire. The characteristics of this long-term produced wire and the characteristics of the electric wire of Example 5 were substantially the same. The characteristics of the electric wires of Reference Example 5 and Examples 4 to 6 are shown in Table 2. Example 7 Polyurethane varnish (Varnish D) was applied and baked several times on a copper wire with a diameter of 0.10 mm, and then the wire was brought into contact with a grooveless rotating roller rotating at a constant speed to form a melt of solid paraffin (melting point 54). ℃) was applied in a required amount, and then passed through a heating equalization section to obtain a lubricating insulated wire. The temperature of the roller was 100°C, and the temperature of the felt in the equalization section was 120°C. Example 8 Polyurethane (varnish E) was applied and baked several times on a copper wire with a diameter of 0.05 mm, then the wire was brought into contact with a grooveless roller rotating at a constant speed, a solid paraffin melt was applied, and then heated. A lubricious insulated wire was obtained by passing through a homogenizing section. After continuing baking and lubricating for 3 days in the same manner, a sample was taken and the properties of this sample were also evaluated, and the properties were essentially the same as those of the initially coated product. Example 9 Varnish B was repeatedly applied and baked on a copper wire with a diameter of 0.2 mm, and varnish C was further baked on top of this, after which solid paraffin (mp 54-56°C) and polyethylene glycol-6000 were mixed in a ratio of 500 g and 100 g. The solution was applied with a groove roller having a groove diameter of 0.5 (mm) at a liquid temperature of 60°C. Immediately thereafter, it was passed through Teflon felt between heating plates to make it uniform. The temperature of the Teflon felt was 85°C. Table 3 shows the characteristics of the obtained electric wire.

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【table】 [Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an apparatus for implementing the melt coating method of the present invention, in which 1 is a container having a heating function, 2 is a melt, 3 is a roller, 4 is an insulated wire, 5, 5' is a heating plate, and 6 and 6' are equalization parts.

Claims (1)

[Scope of Claims] 1. When applying a lubricant that is solid at room temperature in a molten state to an insulated wire, the required amount is applied and supplied by a rotating roller, and then the lubricant is immediately applied to the heating uniform part 5,
A method for melt-applying a room-temperature solid lubricant onto an insulated wire, characterized by passing the lubricant through 5', 6, and 6'. 2. The method of melting and applying a room temperature solid lubricant to an insulated wire according to claim 1, wherein the roller is a grooved roller. 3. The method of melting and applying a room temperature solid lubricant to an insulated wire according to claim 2, wherein the groove shape of the roller is semicircular or U-shaped. 4. The method for melt-coating a room-temperature solid lubricant onto an insulated wire according to claim 1, wherein the temperature of the heating equalization section is higher than the temperature of the coating supply section. 5. The method of melting and applying a room temperature solid lubricant to an insulated wire according to claim 1, wherein the homogenizing material in the heating homogenizing section is felt or granules.