Hot coating type enameled wire lubricant

Abstract

The invention belongs to the technical field of lubricants, and discloses a hot coating type enameled wire lubricant, which is composed of the following components by weight: 40-60 parts of high flash point solvent oil; 5 to 15 parts of polyester wax; 5 to 15 parts of an organosilicon compound; 1-5 parts of mineral oil; 1 to 5 parts of a surfactant; wherein the closed-cup flash point of the lubricant is greater than or equal to 40 DEG C, and the solid content is greater than or equal to 20wt%; the solvent with the closed-cup flash point larger than or equal to 40 DEG C is adopted, so that the lubricant is separated from the category of class A dangerous goods, and the combustion explosion risk is fundamentally eliminated; the solid content is increased to be greater than or equal to 18.8% from the traditional 1.5%, and the solvent volatilization amount is actually measured to be only 8.2-9.1 g / h in combination with a thermal coating process and is reduced by 95% or above compared with a traditional process.

Description

Technical Field

[0001] This invention relates to the field of lubricant technology, and in particular to a heat-coating type enameled wire lubricant. Background Technology

[0002] Currently, the common method for lubricating enameled wires is felt coating, which requires diluting the concentrated lubricant to a concentration of 1%~2% with 120# solvent oil (flash point -8°C) or cyclohexane. These solvents are classified as Class A flammable materials under GB 50058-2014, and industry statistics over the past three years show that solvent-related fires account for 17% of all fire accidents (China Electrical Equipment Industry Association Cable Branch 2024 Annual Report).

[0003] The defects are as follows: ① Severe solvent evaporation: During the production process, >98% of the solvent evaporates into the air (measured VOC emissions >200g / h·100m³). 3 This pollutes the environment and wastes raw materials. ② High safety risk: Low flash point solvents are prone to forming explosive gas mixtures in the coating area, which can explode upon contact with equipment sparks; ③ Cumbersome operation: Switching to different line gauges requires re-preparing the diluent, and downtime accounts for 15% of the production cycle.

[0004] The core problem solved by this invention is to completely eliminate the use of Class A solvents while ensuring lubrication performance, thereby achieving a safe, environmentally friendly, and efficient direct coating process. Summary of the Invention

[0005] The main objective of this invention is to provide a hot-coating type enameled wire lubricant, which aims to solve the technical problems of >98% solvent evaporation into the air during the production process, which pollutes the environment and wastes raw materials; low flash point solvents easily form explosive mixed gases in the coating area, which will explode upon contact with equipment sparks; and the need to re-prepare the diluent when switching to different wire gauges, resulting in downtime accounting for 15% of the production cycle.

[0006] To achieve the above-mentioned objective, the first aspect of this invention provides a heat-coating type enameled wire lubricant, comprising the following components in parts by weight: High flash point solvent oil: 40-60 parts; Polyester wax: 5-15 parts; Organosilicon compounds: 5–15 parts; Mineral oil: 1-5 parts; Surfactant: 1-5 parts; The lubricant has a closed-cup flash point ≥40°C and a solid content ≥20wt%.

[0007] Furthermore, the high flash point solvent oil is an alkane solvent with a flash point ≥40°C, preferably D40 solvent oil or D60 solvent oil.

[0008] Furthermore, the polyester wax has a molecular weight of 1000–5000 g / mol and a melting point of 50–90°C.

[0009] Furthermore, the organosilicon compound is selected from at least one of amino-modified polysiloxane, polyether-modified polysiloxane, or methylphenyl silicone oil.

[0010] Furthermore, the surfactant is an anionic surfactant, preferably a sulfonate or phosphate salt surfactant.

[0011] This invention also protects a method for preparing a heat-coated enameled wire lubricant, comprising the following steps: (a) Add high flash point solvent oil to a stirred reactor equipped with a heating device; (b) Add polyester wax and heat it to 60±2°C while stirring to melt and disperse it; (c) Add organosilicon compounds, mineral oil and surfactants, and maintain stirring for 30 ± 5 minutes; (d) Cool down to below 40°C, and then filter through a 100-200 mesh sieve while continuously stirring before packaging.

[0012] Furthermore, a method for applying lubricating coating to enameled wire is achieved through the following steps: (a) Place the lubricant in the heated roller device and control the temperature at 40–60°C; (b) The surface of the enameled wire comes into direct contact with the rotating lubricant-coated roller; (c) The amount of lubricant applied to the surface of the enameled wire is controlled by adjusting the speed of the roller.

[0013] Furthermore, the coating amount is controlled at 0.2–1.0 g / m by the roller rotation speed. 2 The range is wide, and there is no need to adjust the concentration using dilution solvents.

[0014] Furthermore, the coefficient of static friction of the coating formed by the lubricant on the surface of the enameled wire is 0.03 to 0.07.

[0015] Furthermore, the application of hot-applied lubricants in enameled wire manufacturing replaces the felt coating method containing flammable solvents, enabling a production process free of Class A hazardous solvents.

[0016] Beneficial effects: The beneficial effects of the hot-coating type enameled wire lubricant of the present invention are derived based on the content of claim 1.

[0017] 1. This invention uses a solvent with a closed-cup flash point of ≥40°C, which removes the lubricant from the category of Class A hazardous materials and fundamentally eliminates the risk of combustion and explosion. The solid content is increased from the traditional 1.5% to ≥18.8%. Combined with the hot coating process, the measured solvent evaporation is only 8.2-9.1g / h, which is more than 95% lower than the traditional process.

[0018] 2. This invention eliminates the solvent preparation process and allows direct application of the original solution, reducing production line changeover time by 70%. The coating amount is linearly adjusted by the roller speed, overcoming the uneven coating caused by concentration fluctuations in the traditional felt method. A single concentration of lubricant can cover wire gauges of Φ0.3-1.0mm, eliminating the need to formulate multiple concentrations of lubricant for different wire diameters.

[0019] 3. The static friction coefficient of the present invention is stable at 0.036-0.048, which is comparable to that of the traditional solvent method and meets the lubrication requirements of GB / T6109.1-2018 enameled wire; moreover, the raw material cost and environmental protection cost are reduced, saving solvent oil and VOC treatment costs. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for preparing a heat-coated enameled wire lubricant according to an embodiment of the present invention.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] See Figure 1 An embodiment of the present invention provides a heat-coating type enameled wire lubricant, which is composed of the following components in parts by weight: High flash point solvent oil: 40-60 parts; Polyester wax: 5-15 parts; Organosilicon compounds: 5–15 parts; Mineral oil: 1-5 parts; Surfactant: 1-5 parts; The lubricant has a closed-cup flash point ≥40°C and a solid content ≥20wt%.

[0027] The high flash point solvent oil is an alkane solvent with a flash point ≥40°C, preferably D40 or D60 solvent oil. The polyester wax has a molecular weight of 1000–5000 g / mol and a melting point of 50–90°C. The organosilicon compound is selected from at least one of amino-modified polysiloxanes, polyether-modified polysiloxanes, or methylphenyl silicone oil. The surfactant is an anionic surfactant, preferably a sulfonate or phosphate salt surfactant.

[0028] Note: High flash point solvent oil (40-60 parts), as the continuous phase of the system, must meet the following requirements: Distillation range 230-280℃ (ASTM D86); Aromatic hydrocarbon content <1% (GB / T 11132-2008); Kinematic viscosity (40℃) 2.5-4.0 mm2 / s (GB / T 265-2021); D40 / D60 solvent oils are preferred due to their narrow fractionation characteristics, which can avoid component imbalance caused by high-temperature volatilization. Experiments show that when the solvent oil content is <40 parts, the system viscosity is >300 mPa·s, resulting in uneven coating; when it is >60 parts, the solid content is <18%, and the wear resistance of the coating decreases by more than 30%.

[0029] The polyester wax (5-15 parts) uses hydroxyl-terminated polyester wax (acid value < 5 mg KOH / g) with a molecular weight distribution index (PDI) ≤ 1.8 (GPC determination). When the molecular weight is < 1000, the melting point is low (< 50℃), and it is prone to clumping during storage; when the molecular weight is > 5000, the melt viscosity increases dramatically, with a viscosity > 500 mPa·s at 65℃. C28-C36 fatty acid polyesters with an esterification degree of 92-95% are preferred, as they exhibit a significant viscosity abrupt change at 60±5℃, enabling rapid curing after coating.

[0030] Organosilicon compounds (5-15 parts), amino-modified polysiloxanes must meet the following requirements: amine value 0.6-1.2 meq / g (ASTM D2074), viscosity (25℃) 800-1500 mPa·s.

[0031] In polyether-modified polysiloxanes, an EO / PO molar ratio of 3:1 is preferred, with a hydrophilic-lipophilic balance (HLB) value of 4-6. The phenyl content of methylphenyl silicone oil should be controlled at 10-20%; for every 5% increase in phenyl content, the coefficient of friction decreases by 0.008-0.012.

[0032] This invention also protects a method for preparing a heat-coated enameled wire lubricant, comprising the following steps: (a) Add high flash point solvent oil to a stirred reactor equipped with a heating device; (b) Add polyester wax and heat it to 60±2°C while stirring to melt and disperse it; (c) Add organosilicon compounds, mineral oil and surfactants, and maintain stirring for 30 ± 5 minutes; (d) Cool down to below 40°C, and then filter through a 100-200 mesh sieve while continuously stirring before packaging.

[0033] (a) Solvent oil pretreatment: The high flash point solvent oil is dehydrated by molecular sieve to a water content of <200ppm (Karl Fischer process GB / T 6283-2008) and injected into an anchor-type stirred tank with frequency conversion control (diameter-to-height ratio 1:1.5-2.0). (b) Melt dispersion: The temperature is gradually increased to 60±2℃ at a rate of 5℃ / min, and polyester wax particles (particle size ≤2mm) are added, maintaining a shear rate of 300-500s. -1The heat preservation time t (min) = 0.15 × molecular weight / 1000 (e.g., 52.5 min for a molecular weight of 3500, and 15 minutes is the minimum critical value in Example 1). (c) Blending modification: Keeping the stirring Reynolds number Re > 10000, add organosilicon compound, mineral oil and surfactant preheated to 50°C in sequence, and use a cross-flow mixer to enhance dispersion; (d) Filtration and packaging: Slowly cool to below 40℃ at 0.5℃ / min, filter through a 150-200 mesh multi-layer vibrating screen (316L stainless steel), and then seal in nitrogen-filled packaging.

[0034] A method for applying lubricating coating to enameled wire is achieved through the following steps: (a) Place the lubricant in the heated roller device and control the temperature at 40–60°C; (b) The surface of the enameled wire comes into direct contact with the rotating lubricant-coated roller; (c) The amount of lubricant applied to the surface of the enameled wire is controlled by adjusting the speed of the roller.

[0035] The coating amount is controlled at 0.2–1.0 g / m by the roller rotation speed. 2 The lubricant has a range of properties that can be adjusted without the need for dilution solvents. The static friction coefficient of the coating formed by the lubricant on the enameled wire surface is 0.03 to 0.07.

[0036] Example 1 A heat-coating type enameled wire lubricant, comprising the following components in parts by weight: D40 solvent oil (closed-cup flash point 42℃): 45 parts; Polyester wax (molecular weight 3500, melting point 80℃): 10 parts; Amino-modified polysiloxane: 8 parts; 150SN mineral oil: 3 parts; Sodium dodecylbenzenesulfonate: 2 parts.

[0037] The D40 solvent oil (alkane content ≥98%) serves as the base carrier, and its narrow distillation range (230-260℃) ensures that the solvent evaporation rate matches the coating process. Polyester wax (hydroxyl value 35mgKOH / g) forms a spatial network structure in the molten state, imparting shear resistance to the coating. Amino-modified polysiloxane (amine value 0.8mmol / g) undergoes directional adsorption through hydrogen bonding between amino groups and carboxyl groups in the paint film, reducing interfacial energy. 150SN mineral oil (VI index ≥95) acts as a plasticizer to improve low-temperature fluidity. Sodium dodecylbenzenesulfonate enhances wetting and spreading properties by reducing the liquid / solid interfacial tension (≤28mN / m). The synergistic effect of each component satisfies: ① a rheological window of 80-90 mPa·s dynamic viscosity at 40℃; ② a coating surface energy ≤25mN / m.

[0038] A method for preparing a heat-coated enameled wire lubricant includes the following steps: (a) Add D40 solvent oil to a 200L jacketed stirred tank (anchor impeller, 200rpm); (b) Add polyester wax particles, heat to 60±2℃ with steam, keep warm and stir for 15 minutes until completely melted; use an anchor-type stirring paddle (blade-to-vessel wall gap ≤5mm) with a rotation speed of 200rpm to form an axial-radial composite flow field (Reynolds number Re=3200) so that the polyester wax melt particle size is ≤10μm.

[0039] (c) Add amino silicone oil, mineral oil, and surfactant sequentially, and maintain a constant temperature of 60°C while stirring for 30 minutes. First, add preheated mineral oil (60°C) to reduce the viscosity of the system, and then add surfactant dropwise (addition rate ≤200g / min) to prevent local micelle aggregation. Temperature sensitivity verification: When the temperature is <55°C, wax crystal precipitation causes D50 >25μm detected by laser particle size analyzer (GB / T19077-2016); when the temperature is >70°C, TG-DSC detects the breaking of organosilanes oxygen bonds (the point of sudden increase in weight loss is 72°C).

[0040] (d) Stop heating, cool down to 35°C with cooling water, filter through a 150-mesh stainless steel screen and then pack into barrels.

[0041] Results: Closed-cup flash point (GB / T 261-2021): 43℃; Solid content (dried at 150℃ for 1h): 20.2%; Viscosity (40℃, GB / T 265-2021): 85 mPa·s.

[0042] Furthermore, the product application based on Example 1 is as follows: Application conditions: Enamelled wire specifications: Φ0.3mm polyesterimide enameled copper wire; Coating equipment: Horizontal stainless steel roller (diameter 200mm, effective length 500mm); Lubricant temperature: 50±1℃ (temperature controlled by constant temperature water bath); Drum speed: 30 rpm; Cable routing speed: 100 m / min.

[0043] The application results are shown in the table below:

[0044] After 1000 bending tests (GB / T 4074.3-2008), the coefficient of friction increment Δμ ≤ 0.005; high temperature stability: after 100 hours of heat aging at 150℃, no coating migration was observed (FTIR test at 1720cm). -1The intensity decay rate of the characteristic peak of the ester group is ≤3%; compatibility verification: after contact with polyesterimide paint film for 168 hours, the adhesion retention rate of the paint film is ≥95% (cross-cut test GB / T 9286-1998). Economic comparison: compared with solvent-based lubricant (solid content 8%), the unit coating cost is reduced by 42% (based on a coating amount of 0.45g / m). 2 count).

[0045] Example 2 A heat-coating type enameled wire lubricant, comprising the following components in parts by weight: D60 solvent oil (closed-cup flash point 62℃): 55 parts; Polyester wax (molecular weight 4200, melting point 85℃): 8 parts; Polyether-modified polysiloxane: 12 parts; 120BS gloss varnish: 2 parts; Nonylphenol polyoxyethylene ether phosphate: 3 parts.

[0046] Among them, D60 solvent oil (aromatic content ≤0.5%) ensures a safe production environment with a flash point >55℃; polyester wax with a molecular weight of 4200 (acid value ≤3mgKOH / g) is selected to improve the coating hardness (pencil hardness H grade); polyether-modified polysiloxane (EO / PO=3:1) associates with water molecules through ether bonds, giving it moisture resistance (friction coefficient fluctuation ≤0.005 at 90%RH); 120BS bright oil (pour point -15℃) inhibits low-temperature crystallization; nonylphenol polyoxyethylene ether phosphate has both wetting and antistatic functions (surface resistivity ≤10). 9 Ω·cm). Particularly suitable for motor windings in high humidity environments (such as enameled wire for compressors).

[0047] A method for preparing a heat-coated enameled wire lubricant includes the following steps: (a) Using the same equipment as in Example 1, add D60 solvent oil; (b) Add polyester wax and heat to 65±2℃ (due to its high melting point) and stir for 20 minutes; (c) Add polyether silicone oil, bright oil, and phosphate surfactant, and stir at 65°C for 30 minutes; (d) Cool down to 38°C and filter through a 180-mesh sieve.

[0048] Furthermore, due to the system viscosity reaching 110 mPa·s (40℃), a shear rate of ≥500 s must be maintained when filtering with an 180-mesh sieve. -1 (Achieved via an inline high-shear pump); gradient cooling (65℃→50℃ rate 2℃ / min, 50℃→40℃ rate 1℃ / min) is used to prevent wax phase separation. In a 2000L reactor, the stirring power is increased (power input per unit volume from 0.8kW / m³). 3Increased to 1.2kW / m 3 Ensure consistent dispersion (viscosity RSD ≤ 3% for three batches of products).

[0049] Results: Closed-cup flash point: 58℃; Solid content: 22.5%; Viscosity: 110 mPa·s.

[0050] The product application based on Example 2 is as follows: Application conditions: Enameled wire specifications: Φ0.5mm polyurethane enameled wire; Drum speed: 25 rpm (due to high viscosity); Lubricant temperature: 52±1℃; Cable routing speed: 80 m / min.

[0051] The application results are shown in the table below:

[0052] After immersion in refrigerant R134a for 240 hours, the coating mass loss rate is ≤0.3%; the increase in the dielectric loss factor tanδ (1kHz) is ≤5×10. -4 The coating showed no cracks after 500 cold start tests at -40℃ (SEM observation at 1000x magnification). It passed EU RoHS 2.0 testing (Cd < 5 ppm, Pb < 15 ppm).

[0053] Example 3 A heat-coating type enameled wire lubricant, comprising the following components in parts by weight: D60 solvent oil: 60 parts; Polyester wax (molecular weight 2800, melting point 75℃): 12 parts; Methylphenyl silicone oil (phenyl content 15%): 10 parts; Naphthenic mineral oil: 4 parts; Alkyl naphthalene sulfonate: 1 part.

[0054] The system employs a high-phenyl-content silicone oil (phenyl molar fraction 15%) to enhance thermal stability (TGA test showed a 5% weight loss temperature of 280℃); a cycloalkyl mineral oil (cycloalkane content ≥40%) to provide excellent compatibility; and an alkyl naphthalene sulfonate (sulfonation degree ≥95%) to form a chemisorption film on the metal surface. Rheological design: By adjusting the polyester wax / mineral oil ratio (12:4), the system exhibits pseudoplastic fluid characteristics (shear thinning index n=0.82), ensuring uniform coating at high linear speeds (50m / min).

[0055] A method for preparing a heat-coated enameled wire lubricant includes the following steps: (a) The solvent oil is added to the reactor and then heated to 60°C; (b) Add polyester wax and stir for 15 minutes until a clear solution is obtained; (c) Add methylphenyl silicone oil, mineral oil, and surfactant, and stir at 60°C for 30 minutes; (d) Cool to 40°C and filter through a 100-mesh sieve (due to high viscosity).

[0056] For a high-viscosity system of 205 mPa·s, a three-stage filtration system was used: ① 100-mesh coarse filter (pressure difference ≤ 0.1 MPa) ② 20 μm bag filter ③ online centrifugation (3000 rpm, removing particles ≥ 5 μm). No precipitation was observed after 6 months of storage at 40℃ (precipitation amount ≤ 0.1% when measured in centrifuge tubes at 4000 rpm × 15 min).

[0057] Results: Closed-cup flash point: 61℃; Solid content: 18.8%; Viscosity: 205 mPa·s.

[0058] Furthermore, the product application based on Example 3 is as follows: Application conditions: Enamelled wire specifications: Φ1.0mm corona-resistant enamelled wire; Drum speed: 35 rpm (compensation for high viscosity); Lubricant temperature: 55±1℃; Cable routing speed: 50 m / min.

[0059] The application results are shown in the table below:

[0060] Compared to traditional solvent-based processes, eliminating the drying step (80-120℃) reduces energy consumption by 65 kWh / t of product; by eliminating solvent evaporation waiting time, the production line changeover interval is shortened from 45 minutes to 8 minutes; traditional processes use xylene diluent (addition amount 30-50%), while this technology achieves zero solvent addition. Life cycle assessment: From raw material production to coating application, the carbon footprint is reduced by 52% (calculated according to ISO 14040 standard).

[0061] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A heat-coating type enameled wire lubricant, characterized in that, It consists of the following components in parts by weight: High flash point solvent oil: 40-60 parts; Polyester wax: 5-15 parts; Organosilicon compounds: 5–15 parts; Mineral oil: 1-5 parts; Surfactant: 1-5 parts; The lubricant has a closed-cup flash point ≥40°C and a solid content ≥20wt%.

2. The heat-coating type enameled wire lubricant according to claim 1, characterized in that, The high flash point solvent oil is an alkane solvent with a flash point ≥ 40°C, preferably D40 or D60 solvent oil.

3. The heat-coating type enameled wire lubricant according to claim 1, characterized in that, The polyester wax has a molecular weight of 1000–5000 g / mol and a melting point of 50–90°C.

4. The heat-coating type enameled wire lubricant according to claim 1, characterized in that, The organosilicon compound is selected from at least one of amino-modified polysiloxane, polyether-modified polysiloxane, or methylphenyl silicone oil.

5. The heat-coating type enameled wire lubricant according to claim 1, characterized in that, The surfactant is an anionic surfactant, preferably a sulfonate or phosphate salt surfactant.

6. A method for preparing a heat-coating type enameled wire lubricant according to any one of claims 1-5, characterized in that, Includes the following steps: (a) Add high flash point solvent oil to a stirred reactor equipped with a heating device; (b) Add polyester wax and heat it to 60±2°C while stirring to melt and disperse it; (c) Add organosilicon compounds, mineral oil and surfactants, and maintain stirring for 30 ± 5 minutes; (d) Cool down to below 40°C, and then filter through a 100-200 mesh sieve while continuously stirring before packaging.

7. A method for applying lubricating coating to enameled wire, characterized in that, The lubricant described in any one of claims 1-5 is used to achieve the following steps: (a) Place the lubricant in the heated roller device and control the temperature at 40–60°C; (b) The surface of the enameled wire comes into direct contact with the rotating lubricant-coated roller; (c) The amount of lubricant applied to the surface of the enameled wire is controlled by adjusting the speed of the roller.

8. The method for applying lubricating coating to enameled wire according to claim 7, characterized in that, The coating amount is controlled at 0.2–1.0 g / m by the roller rotation speed. 2 The range is wide, and there is no need to adjust the concentration using dilution solvents.

9. The method for applying lubricating coating to enameled wire according to claim 7, characterized in that, The coefficient of static friction of the coating formed by the lubricant on the surface of the enameled wire is 0.03 to 0.

07.

10. The application of a heat-coating lubricant as described in any one of claims 1-5 in the manufacture of enameled wire, characterized in that, An alternative to felt coating methods containing flammable solvents, enabling a production process free of Class A hazardous solvents.

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