JPS623527B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a lubricious 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 equipment, there is a serious problem in that rare shots occur and the loss rate increases significantly. 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. The number of layered seats is increasing due to the expansion of the application of the inserter method that improves the 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 deal with the problem by dissolving approximately 1% solid paraffin in a solvent such as benzine or xylene and applying it to the wire surface, 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. The present inventors have arrived at the method of the present invention as a result of intensive studies to solve these problems. The present invention provides an insulated wire with excellent lubricity by heating and melting a solid organic lubricant at room temperature and applying it onto an enameled wire without using a solvent. 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. 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, a part of the skeleton of the alkyl group consists of -( _CH2- ) _o , and n20 is preferable. The average molecular weight of the lubricant is preferably 100 or less. This is because if the molecular weight is too large, the melt viscosity will be high, making coating difficult, or the melting point or softening point will be too high, leading to thermal decomposition, which is undesirable. Next, examples of lubricants used in the present invention will be given. Among the various lubricants, those having the above-mentioned carbon number of the alkyl group, skeleton of the alkyl group,
Needless to say, it satisfies the average molecular weight, etc. Examples include hydrocarbons, fatty acids or derivatives thereof,
Examples include alcohol or its derivatives, fatty acid amide or its derivatives, waxes, greases, and the like. 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, 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, heptacanoic 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 derivatives thereof 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, nonadecan 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 with the hydrogen of the amino group replaced by an alkyl group, those with the general formula RCONH-CH ₂ -NHCOR, RCONH
There is a bis fatty acid amide represented by _-CH2 - _CH2 -NHCOR. 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. A feature of the present invention is that two or more organic lubricants having a melting point of 56°C or lower and an organic lubricant having a melting point of 60°C or higher are used as a mixture. 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. 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. Heating temperature is 150℃
If the temperature exceeds 150°C, the lubricant may decompose and even generate smoke, so a temperature of 150°C or lower is preferable. 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 high melting point. This is preferable because it can be used in As mentioned earlier, solid paraffin is the most preferred 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. It can be said that it is a preferable lubricant considering these meanings. There are no restrictions on the enamelled wire used in the present invention. That is, the wire may be a round wire or a rectangular wire, and 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 manual work is performed. 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, any method may be used to apply the heated and melted lubricant. Of course, it goes without saying that a method in which the coating is applied uniformly is preferable. Coating methods include a dipping method in which an enameled wire is directly passed through heated and molten lubricant, a groove roller method, and a wiper roller method. Alternatively, there is a method of impregnating heated and molten lubricant into felt and passing the lubricant over or between the felt to apply the lubricant. Felt can also be used for both coating and drawing. Of course, the above coating methods can also be combined. The enameled wire coated with lubricant can be used as is, or it can be squeezed. The reason for squeezing is to make the coating thickness of the lubricant uniform and constant. Any method may be used for the aperture. For example, die drawing, rubber drawing,
There is a felt diaphragm. 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 application section and/or the squeezing section. This prevents the lubricant from solidifying, making it possible to achieve uniform application and squeezing. It is more preferable that the application part and/or the squeeze part be heated felt. Felt application and/or squeezing is an excellent method for applying thinly and uniformly, and heating the felt is preferred because it prevents solidification of the lubricant. 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 coated enameled wire itself in advance. This is because if the enameled wire is heated, it is possible to prevent the molten lubricant from solidifying. 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.
This is because it improves slippage and reduces damage. However, the fact that it is not applied evenly means that there are areas with poor slippage, which increases the possibility of damage.Also, in places where the wire is used by hand, the line is not well distributed and slippery, so it is not evenly coated. Needless to say, it is preferable that the coating be applied to 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 actual series, 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 then 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. Wire handling properties were determined through a sensory test in which a wire was picked up from a cigarette and the wire was handled to the touch to determine the quality. 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 C3003 reciprocating abrasion tester with a load of 290 g. Note that the original in Table 1 is an enameled wire without lubricant applied thereto. The insulating paints used in the examples are shown below. Varnish A: Delacote E 220G (polyester insulating paint sold by Nitto Electric Industries, Ltd.) Varnish B: Isomyd LV (polyester imide insulating paint sold by Nippon Schenectaday Co., Ltd.) Varnish C: HI-400 (Hitachi Chemical Co., Ltd.) Varnish D: An insulating paint made by dissolving 6.6-nylon in m-cresol. Varnish E: Self-fusing paint made by dissolving phenoxy resin in m-cresol. Example 1 Varnish A was repeatedly coated and baked on a copper wire with a diameter of 0.65 mm several times. Varnish C was repeatedly coated and baked on top of that several times, and then 400 g of solid paraffin with a melting point of 54-56°C and a melting point of 68-70 200g solid paraffin at ℃
A lubricious insulated wire was obtained by heating and melting a solid paraffin mixture at 65°C. The solid paraffin was applied with a groove roller, and then the electric wire immediately after the application was squeezed with a felt impregnated with molten paraffin, and further squeezed with a rubber. In addition, felt is 100
A block heated to ℃ was placed on it, and the rubber was kept in close contact with the felt. Table 1 shows the properties of the obtained lubricious insulated wire. Example 2 Varnish A was repeatedly coated and baked on a copper wire with a diameter of 0.2 mm several times. Varnish D was coated and baked on top of that, and then 400 g of solid paraffin with a melting point of 54 to 56°C and solid paraffin with a melting point of 68 to 70°C were added on top of that. A lubricious insulated wire was obtained by heating and melting 200 g of solid paraffin mixed at 70°C, applying it with a groove roller, and squeezing it with felt impregnated with the melted paraffin.
A block heated to 100°C was placed on the felt. Table 1 shows the properties of the obtained lubricious insulated wire. Example 3 Varnish B was repeatedly coated and baked several times on a copper wire with a diameter of 1.0 mm. Varnish C was repeatedly coated and baked on top of that several times, and then 400 g of solid paraffin with a melting point of 54 to 56°C and a melting point of 68 to 70°C were added on top of that. Solid paraffin mixed with solid paraffin was heated and melted at 65°C, applied with a groove roller, and further squeezed with felt impregnated with molten paraffin to obtain a lubricating insulated wire.
A block heated to 100°C was placed on the felt. 【table】

Claims (1)

[Claims] 1. A method of heating and melting an organic lubricant that is solid at room temperature and applying it to an enameled wire, which comprises two types of organic lubricants: one with a melting point of 56°C or lower and one with a melting point of 60°C or higher. A method for manufacturing a lubricating insulated wire, characterized by using a mixture of the above. 2 below the highest melting point of two or more organic lubricants,
2. The method for producing a lubricating insulated wire according to claim 1, wherein the organic lubricant is heated and melted at a temperature equal to or higher than the lowest melting point. 3. The method for manufacturing a lubricious insulated wire according to claim 1, wherein the lubricious insulated wire has a static friction coefficient of 0.1 or less. 4. A lubricious insulated wire according to claim 1, wherein the main component is at least one organic lubricant having an alkyl group of 21 or more carbon atoms among two or more organic lubricants that are solid at room temperature. Production method. 5. The method for producing a lubricious insulated wire according to claim 4, wherein a part of the skeleton of the alkyl group consists of -( _CH2- ) _o and is n20. 6. The method for producing a lubricating insulated wire according to claim 1, wherein the lubricant has an average molecular weight of 1000 or less. 7. The method for producing a lubricating insulated wire according to claim 1, wherein the average thickness of the lubricant applied to the enameled wire is 1 micron or less.