Drawing lubricant as well as preparation method and application thereof

Abstract

The invention provides a wire drawing lubricant as well as a preparation method and application thereof. The wire drawing lubricant comprises the following components in percentage by mass: 15%-20% of graphite fluoride, 1%-5% of a surfactant, 5%-8% of a binder, 2%-10% of a thickening agent, 2%-10% of ammonia water and 47%-75% of water. According to the invention, a specific content of graphite fluoride is added into the wire drawing lubricant, so that the lubricating property of the wire drawing lubricant is improved, and the wire drawing lubricant can meet the requirements of tungsten wire drawing on the lubricant. Specifically, the graphite fluoride has the advantages of low surface energy, small interlayer bond energy, stable chemical performance, stable thermal performance and the like, and can be mutually matched with other components, so that the lubricating performance of the wire drawing lubricant is improved.

Description

Technical Field

[0001] The present application relates to the technical field of metal processing lubricants, and in particular to a wire drawing lubricant and a preparation method and application thereof. Background Art

[0002] With the increasing development of the photovoltaic industry, the demand for diamond wire saws for cutting silicon wafers is also increasing. The development trend of silicon wafer size is to become larger and thinner. Correspondingly, diamond wire saws usually need to meet the requirements of high tensile strength, high breaking force, long length, large loop diameter, and small wire diameter.

[0003] Currently, the commonly used diamond wire saws include rare earth doped tungsten wire. Rare earth doped tungsten wire has excellent properties such as tensile strength, breaking force, wear resistance and corrosion resistance, and can meet the cutting requirements of high-performance silicon wafers, but it has disadvantages such as high processing difficulty. In the preparation process of rare earth doped tungsten wire, in addition to the quality of rare earth doped tungsten raw materials, wire drawing equipment, processes, dies, and wire drawing lubricants used in the dies during the wire drawing process will affect the yield rate of tungsten wire busbars. Usually, the wire drawing speed of tungsten wire exceeds 100 meters / minute, and the temperature of the wire drawing die can be as high as 400℃~500℃, so there are also high requirements for the lubricant added to the wire drawing die. Graphite emulsion is often used as a tungsten wire drawing lubricant in traditional technology, but graphite emulsion has the disadvantages of being expensive and having poor lubrication performance.

[0004] Therefore, it is necessary to improve the traditional wire drawing lubricants. Summary of the invention

[0005] Based on this, one or more embodiments of the present application provide a wire drawing lubricant with good lubrication performance and a preparation method and application thereof.

[0006] According to a first aspect of an embodiment of the present application, a wire drawing lubricant is provided, which includes the following components, calculated by mass percentage: 15% to 20% graphite fluoride, 1% to 5% surfactant, 5% to 8% binder, 2% to 10% thickener, 2% to 10% ammonia water and 47% to 75% water.

[0007] In one embodiment, the surfactant is selected from one or more of polyethylene glycol 2000 and sodium petroleum sulfonate.

[0008] In one embodiment, the binder is selected from polyvinyl alcohol, polyethylene glycol or cellulose ether.

[0009] In one embodiment, the thickener is selected from methylcellulose, hydroxypropyl methylcellulose or sodium methylcellulose.

[0010] In one embodiment, the D50 particle size of the fluorinated graphite is 0.6 μm to 1.0 μm.

[0011] In one embodiment, the particle size range of the fluorinated graphite is 1.0 μm to 1.5 μm.

[0012] According to a second aspect of an embodiment of the present application, a method for preparing the above-mentioned wire drawing lubricant is provided, comprising the following steps:

[0013] Mixing graphite fluoride, a surfactant, a binder, a thickener, ammonia water and water, and dispersing them uniformly to obtain a mixture;

[0014] The mixture is ball-milled to prepare the wire drawing lubricant.

[0015] In one embodiment, the fluorinated graphite is prepared by the following steps:

[0016] The ultrafine particle graphite is subjected to graphitization treatment and fluorination treatment in sequence to obtain the fluorinated graphite;

[0017] Optionally, the particle size of the ultrafine graphite particles is less than or equal to 1 μm.

[0018] In one embodiment, the preparation method satisfies at least one of the following characteristics:

[0019] (1) The temperature of graphitization treatment is 2900℃~3100℃, and the holding time is 3h~5h;

[0020] (2) The temperature of fluorination treatment is 600℃~650℃;

[0021] (3) the fluorinating agent for fluorination treatment is selected from one or more of fluorine gas or Freon;

[0022] (4) During the fluorination treatment, the gas flow rate of the fluorinating agent is 0.8m 3 / h~1.2m 3 / h;

[0023] (5) The fluorination treatment time is 3h~5h.

[0024] According to a third aspect of an embodiment of the present application, there is provided an application of the above-mentioned wire drawing lubricant or the wire drawing lubricant prepared by the above-mentioned preparation method in the preparation of cutting wire drawing.

[0025] Compared with the traditional technology, this application has the following beneficial effects:

[0026] The present application improves the lubricating performance of the wire drawing lubricant by adding a specific amount of fluorinated graphite to the wire drawing lubricant, thereby enabling it to meet the lubricant requirements of tungsten wire drawing. Specifically, fluorinated graphite has the advantages of low surface energy, small interlayer bond energy, stable chemical properties and stable thermal properties, and can cooperate with other components to improve the lubricating performance of wire drawing lubrication.

[0027] In addition, applying the wire drawing lubricant of the present application to the preparation of tungsten wire drawing can increase the wire drawing speed and improve production efficiency; and the prepared tungsten wire has excellent mechanical properties. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. Unless otherwise specifically stated, various raw materials, reagents, instruments and equipment used in the present application, etc. can be purchased from the market or can be prepared by existing methods.

[0030] In the present application, "plurality", "multiple", "multiple times", "multiples", etc., unless otherwise specified, refer to a number greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0031] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0032] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0033] In a first aspect of the present application, a wire drawing lubricant is provided, which comprises the following components, calculated by mass percentage: 15% to 20% graphite fluoride, 1% to 5% surfactant, 5% to 8% binder, 2% to 10% thickener, 2% to 10% ammonia water and 47% to 75% water.

[0034] In the process of tungsten wire drawing, the wire drawing speed usually reaches 100 m / min or even 200 m / min, and the temperature of the wire drawing die can be as high as 400℃~500℃. Ordinary lubricating materials are difficult to match the tungsten wire drawing process. Traditional metal wire drawing lubricants have problems such as easy decomposition and failure, and the lubrication performance cannot meet the requirements during the wire drawing process, which seriously affects the efficient production of tungsten-based steel wire saw busbars (i.e. tungsten wires). The graphite emulsion lubricants commonly used in tungsten wire drawing have the disadvantages of high price, poor procurement channels, uneven particle size, large particle size, high impurity content, poor dispersibility, poor adhesion performance and suspension stability.

[0035] The components of traditional metal wire drawing lubricants mainly include animal fats as base oils, preservatives, brighteners, lubricants, rust inhibitors and coolants. The raw materials of metal wire drawing lubricants are cheap and widely available, and have good lubricity, rust resistance and biodegradability. At the same time, they can increase the drawing speed and reduce the wear of the drawing die. The lubricants are petroleum acids, silicones or nitrides, which are easily decomposed and become ineffective in the tungsten wire drawing process. The above-mentioned metal wire drawing lubricants can be applied to metal wires such as copper, aluminum, and iron, but their high-temperature lubrication performance, impurity content and other properties cannot meet the requirements of tungsten wire drawing for lubricants.

[0036] The ingredients of traditional high-efficiency wire drawing lubricants include talcum powder, rust-proof additives, boron trioxide, boric acid, acrylic resin emulsion, triethanolamine, ethylene glycol oleate, anti-settling agent, thickener, vegetable mixed oil and; the main lubricating ingredients are talcum powder and boron trioxide. This high-efficiency wire drawing lubricant can be used for the wire drawing process of metal wires such as copper, aluminum, and iron, but the friction coefficient cannot meet the requirements of tungsten wire drawing for lubricants.

[0037] Graphite and molybdenum disulfide are more common solid lubricants with better performance. Compared with the above two, graphite fluoride has better high lubricity and is suitable for harsh atmosphere, high speed, high pressure and high temperature conditions, and will not corrode metals and other materials. At the same time, under different temperature conditions, the friction coefficient of graphite fluoride is only half of that of graphite or even lower.

[0038] The molecular formula of fluorinated graphite is CH4F2, and its molecular weight is 54.0393. Graphite fluoride has a low surface energy, and fluorine atoms enter the graphite interlayer and form covalent bonds with π electrons, which significantly reduces the interlayer bond energy of graphite fluoride to only 2Kcal / mol, which is much lower than the interlayer bond energy of raw graphite 9Kcal / mol, making graphite fluoride have excellent lubrication properties. In addition, since the upper and lower surfaces of the hexagonal mesh plane layer of graphite are densely bound with fluorine atoms, there is a repulsive force between the fluorine atoms between the layers, which can offset the pressure from the outside, so graphite fluoride can fully demonstrate excellent lubrication properties. For example, under the condition of 320°C, the friction coefficient of graphite is 0.53, while the friction coefficient of graphite fluoride is only 0.10.

[0039] In some specific embodiments, the wire drawing lubricant includes the following components, measured by mass percentage: 17% to 19% graphite fluoride, 2% to 4% surfactant, 5% to 7% binder, 2% to 5% thickener, 6% to 10% ammonia water and 47% to 65% water.

[0040] In an optional example, the wire drawing lubricant includes the following components, measured by mass percentage: 18% graphite fluoride, 3% surfactant, 6% binder, 2% thickener, 8% ammonia water and 63% water.

[0041] In some embodiments, the D50 particle size of the fluorinated graphite is 0.6 μm to 1.0 μm. As an example, the D50 particle size of the fluorinated graphite can be 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1.0 μm, or a range consisting of any two of these values, such as 0.7 μm to 0.9 μm.

[0042] In some embodiments, the particle size range of the fluorinated graphite is 1.0 μm to 1.5 μm. As an example, the particle size range of the fluorinated graphite may be 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm or 1.5 μm, or a range consisting of any two of these values, such as 1.1 μm to 1.4 μm.

[0043] It can be understood that "particle size range" refers to the difference between the maximum particle size and the minimum particle size in a particle group. That is: particle size range = maximum particle size - minimum particle size.

[0044] In some embodiments, the surfactant is selected from one or more of polyethylene glycol 2000 (PEG2000) and sodium petroleum sulfonate.

[0045] In some embodiments, the binder is selected from polyvinyl alcohol, polyethylene glycol or cellulose ether.

[0046] Optionally, the polyvinyl alcohol is selected from polyvinyl alcohol emulsions.

[0047] In some embodiments, the thickener is selected from methylcellulose, hydroxypropyl methylcellulose or sodium methylcellulose.

[0048] It can be understood that the types of surfactants, binders and thickeners are not limited to the above, and may also be other types commonly used in the art.

[0049] The wire drawing lubricant of the present application has the advantages of low ash content, small friction coefficient, etc., and has good comprehensive lubrication performance, and can be applied to the production process of tungsten wire.

[0050] The second aspect of the present application provides a method for preparing the above-mentioned wire drawing lubricant, comprising steps S10 to S20:

[0051] Step S10: mixing graphite fluoride, a surfactant, a binder, a thickener, ammonia water and water, and dispersing them uniformly to obtain a mixture;

[0052] Step S20: ball-milling the mixture to prepare a wire drawing lubricant.

[0053] It can be understood that the types, usage ratios, etc. of the raw materials in step S10 can refer to the description of the first aspect of the present application.

[0054] In some embodiments, in step S10, graphite fluoride is prepared by the following steps:

[0055] The ultrafine particle graphite is subjected to graphitization treatment and fluorination treatment in sequence to obtain fluorinated graphite.

[0056] In some specific embodiments, the ultrafine particle graphite has a particle size less than or equal to 1 μm.

[0057] In some specific embodiments, the ultrafine graphite particles can be selected from graphite particles with a particle size of less than or equal to 1 μm in the production process of lithium battery graphite negative electrode materials.

[0058] Understandably, ultrafine graphite particles cannot be used in the production process of lithium battery graphite negative electrode materials and are usually only sold at extremely low prices; the particle size of these ultrafine graphite particles meets the requirements of lubricating graphite emulsions, but due to the spherical shape of the particles, the lubrication performance is poor. The present application obtains fluorinated graphite with good lubrication performance by graphitizing, removing impurities, and fluorinating ultrafine graphite particles. The above method for preparing fluorinated graphite has the advantages of abundant material sources, low cost, and stable particle size range.

[0059] Furthermore, the above method for preparing fluorinated graphite can be directly prepared using graphitization equipment for lithium battery graphite negative electrode materials with only slight adjustments; it has the advantages of high production efficiency and low process production cost.

[0060] The fluorinated graphite prepared by the above method has a density of 2.3 g / cm 3 ~2.6g / cm 3 The ash content is less than 0.05%, which is much better than the ash content of 1.5% of domestic graphite milk. The lower ash content can improve the surface quality of the wire and increase the service life of the wire drawing die. The D50 particle size is 0.6μm~1.0μm, and the particle size range is 1.0μm~1.5μm. The fine particle size of fluorinated graphite enables it to have good film-forming performance on the surface of tungsten wire and is easy to coat evenly, which can reduce the use of lubricants and reduce the probability of wire breakage.

[0061] In some of the embodiments, graphite fluoride, pure water, a surfactant and part of ammonia water are first mixed, stirred evenly until the microparticles are dispersed and debonded, and then the remaining part of ammonia water, adhesive and thickener are added, and the mixture is evenly dispersed and mixed by high-speed dispersion, and then the mixture is ball-milled to obtain a wire drawing lubricant.

[0062] In some embodiments, in step S20, after ball-milling the mixture, the following step is further included: screening the ball-milled mixture.

[0063] In some specific embodiments, the temperature of the graphitization treatment is 2900° C. to 3100° C. As an example, the temperature of the graphitization treatment can be 2900° C., 2910° C., 2920° C., 2930° C., 2940° C., 2950° C., 2960° C., 2970° C., 2980° C., 2990° C., 3000° C., 3010° C., 3020° C., 3030° C., 3040° C., 3050° C., 3060° C., 3070° C., 3080° C., 3090° C. or 3100° C.

[0064] In some specific embodiments, the graphitization treatment time is 3 hours to 5 hours. As an example, the graphitization treatment time can be 3 hours, 3.1 hours, 3.2 hours, 3.3 hours, 3.4 hours, 3.5 hours, 3.6 hours, 3.7 hours, 3.8 hours, 3.9 hours, 4 hours, 4.1 hours, 4.2 hours, 4.3 hours, 4.4 hours, 4.5 hours, 4.6 hours, 4.7 hours, 4.8 hours, 4.9 hours or 5 hours.

[0065] In some specific embodiments, the temperature of the fluorination treatment is 600° C. to 650° C. As an example, the temperature of the fluorination treatment can be 600° C., 605° C., 610° C., 615° C., 620° C., 625° C., 630° C., 635° C., 640° C., 645° C., or 650° C.

[0066] In some specific embodiments, the fluorination agent of the fluorination treatment is selected from one or more of fluorine gas or Freon.

[0067] In some specific embodiments, during the fluorination treatment, the gas flow rate of the fluorinating agent is 0.8 m 3 / h~1.2m 3 As an example, the gas flow rate of the fluorinating agent can be 0.8m 3 / h、0.9m 3 / h、1m 3 / h、1.1m 3 / h or 1.2m 3 / h.

[0068] In some specific embodiments, the fluorination treatment time is 3 hours to 5 hours. As an example, the fluorination treatment time can be 3 hours, 3.1 hours, 3.2 hours, 3.3 hours, 3.4 hours, 3.5 hours, 3.6 hours, 3.7 hours, 3.8 hours, 3.9 hours, 4 hours, 4.1 hours, 4.2 hours, 4.3 hours, 4.4 hours, 4.5 hours, 4.6 hours, 4.7 hours, 4.8 hours, 4.9 hours or 5 hours.

[0069] The preparation method of the wire drawing lubricant of the present application has at least the advantages of simple process, low cost and high efficiency.

[0070] The third aspect of the present application provides the use of the wire drawing lubricant of the first aspect or the wire drawing lubricant prepared in the second aspect in the preparation of cutting wire drawing.

[0071] In some embodiments, the cutting wire comprises tungsten wire.

[0072] By using the above-mentioned wire drawing lubricant for tungsten wire drawing preparation, the final tungsten wire has higher breaking force and tensile strength, and larger free circle diameter and length; at the same time, the above-mentioned wire drawing lubricant can increase the wire drawing speed and improve production efficiency.

[0073] The present application will be further described below in conjunction with specific examples and comparative examples, but they should not be construed as limiting the scope of protection of the present application. The raw materials involved in the following specific examples, unless otherwise specified, can all be sourced from commercial sources, the instruments used, unless otherwise specified, can all be sourced from commercial sources, and the processes involved, unless otherwise specified, are all conventionally selected by those skilled in the art.

[0074] Some of the raw materials used in the examples and comparative examples of the present application can be selected from the following:

[0075] PEG2000 was purchased from Henan Wanshan New Materials Technology Co., Ltd., product model 2000;

[0076] Sodium petroleum sulfonate was purchased from Jinan Jinyu Chemical Co., Ltd., product model T702;

[0077] Polyvinyl alcohol was purchased from Shanxi Sanwei Shengtai New Material Technology Co., Ltd., product model 24-88;

[0078] Methyl cellulose was purchased from Shanxi Sanwei Shengtai New Materials Technology Co., Ltd., product model number 200,000;

[0079] Ammonia water was purchased from Hunan Wuchuang Recycling Technology Co., Ltd. with a product model of 25%.

[0080] Embodiment 1:

[0081] (1) The ultrafine graphite particles with a particle size of less than 1 μm left over from the production process of lithium-ion graphite negative electrode materials were heated to 3000°C in an Acheson furnace and graphitized for 4 hours to remove impurities in the ultrafine graphite particles. The temperature in the furnace was then lowered to 635°C and Freon was introduced for fluorination treatment at a gas flow rate of 1 m 3 / h, and react at high temperature for 5h to obtain white powdery graphite fluoride.

[0082] The density of the fluorinated graphite prepared based on the above steps is 2.4 g / cm 3 The ash content is 0.04%, the D50 particle size is 0.8μm, and the particle size range is 1.2μm.

[0083] (2) The raw materials of the wire drawing lubricant are provided according to the following formula: 18 wt % of the fluorinated graphite prepared in step (1), 1 wt % of PEG2000, 2 wt % of sodium petroleum sulfonate, 6 wt % of polyvinyl alcohol emulsion, 2 wt % of methyl cellulose, 8 wt % of ammonia water, and the balance of water.

[0084] According to the above formula, graphite fluoride, surfactant, part of pure water and part of ammonia water are added to a stirring kettle, the pH value is adjusted with ammonia water, and the mixture is stirred and dispersed evenly; after the microparticles are dispersed and the gelatinization requirements are met, the remaining pure water and ammonia water, binder and thickener are added, and after high-speed dispersion for 1 hour in a high-speed disperser, the mixture is added to a vibration ball mill and ball-milled for 10 hours, and then tested and sieved to obtain a wire drawing lubricant.

[0085] The final prepared wire drawing lubricant has a graphite fluoride content of 18%, an ash content of 0.04%, a viscosity of 16 mPa.s, a pH value of 10, and a specific gravity of 1.15 g / cm 3 , D50 particle size is 0.85μm, the particle size range is 1.25μm, and the friction coefficient is 0.26.

[0086] (3) Using the wire drawing lubricant prepared in step (2) to prepare tungsten wire, specifically comprising: using an 8-die wire drawing machine for wire drawing, the diameter of the raw tungsten wire is 80 μm, and the material is tungsten lanthanum alloy; the wire drawing die temperature is 450° C., the temperature of the wire drawing lubricant baking furnace is 400° C., the wire drawing speed is 150 m / h, and the wire drawing die core material is diamond polycrystalline.

[0087] The obtained tungsten wire has an outer diameter of 35 μm, a diameter tolerance of ±0.3 μm, an ellipticity of ≤0.5 μm, a breaking force of 6.15 N, a tensile strength of 6025 MPa, a free circle diameter of 80 mm, and a length of 150 km.

[0088] Embodiment 2:

[0089] (1) The ultrafine graphite particles with a particle size of less than 1 μm left over from the production of lithium-ion graphite negative electrode materials were heated to 3100°C in an Acheson furnace and graphitized for 5 hours to remove impurities in the ultrafine graphite particles. The temperature in the furnace was then lowered to 650°C and Freon was introduced for fluorination treatment at a gas flow rate of 1 m 3 / h, and react at high temperature for 5h to obtain white powdery graphite fluoride.

[0090] The density of the fluorinated graphite prepared based on the above steps is 2.6 g / cm 3 , the ash content is 0.02%, the D50 particle size is 0.8μm, and the particle size range is 1.2μm.

[0091] (2) The raw materials of the wire drawing lubricant are provided according to the following formula: 18 wt % of the fluorinated graphite prepared in step (1), 1 wt % of PEG2000, 2 wt % of sodium petroleum sulfonate, 6 wt % of polyvinyl alcohol emulsion, 2 wt % of methyl cellulose, 8 wt % of ammonia water, and the balance of water.

[0092] According to the above formula, graphite fluoride, surfactant, part of pure water and part of ammonia water are added to a stirring kettle, the pH value is adjusted with ammonia water, and the mixture is stirred and dispersed evenly; after the microparticles are dispersed and the gelatinization requirements are met, the remaining pure water and ammonia water, binder and thickener are added, and after high-speed dispersion for 1 hour in a high-speed disperser, the mixture is added to a vibration ball mill and ball-milled for 10 hours, and then tested and sieved to obtain a wire drawing lubricant.

[0093] The final prepared wire drawing lubricant has a graphite fluoride content of 18%, an ash content of 0.02%, a viscosity of 16 mPa.s, a pH value of 10, and a specific gravity of 1.2 g / cm 3 , D50 particle size is 0.85μm, the particle size range is 1.25μm, and the friction coefficient is 0.21.

[0094] (3) Using the wire drawing lubricant prepared in step (2) to prepare tungsten wire, specifically comprising: using an 8-die wire drawing machine for wire drawing, the diameter of the raw tungsten wire is 80 μm, and the material is tungsten lanthanum alloy; the wire drawing die temperature is 450° C., the temperature of the wire drawing lubricant baking furnace is 400° C., the wire drawing speed is 180 m / h, and the wire drawing die core material is diamond polycrystalline.

[0095] The obtained tungsten wire has an outer diameter of 35 μm, a diameter tolerance of ±0.3 μm, an ellipticity of ≤0.4 μm, a breaking force of 6.25 N, a tensile strength of 6135 MPa, a free circle diameter of 90 mm, and a length of 180 km.

[0096] Embodiment 3:

[0097] The same as Example 1, except that the raw material formula of the wire drawing lubricant is different:

[0098] (2) The raw materials of the wire drawing lubricant are provided according to the following formula: 15 wt % of the fluorinated graphite prepared in step (1), 1 wt % of PEG2000, 1 wt % of sodium petroleum sulfonate, 5 wt % of polyvinyl alcohol emulsion, 2 wt % of methyl cellulose, 2 wt % of ammonia water, and the balance of water.

[0099] The final prepared wire drawing lubricant has a graphite fluoride content of 15%, an ash content of 0.04%, a viscosity of 10 mPa.s, a pH value of 8, and a specific gravity of 1.08 g / cm 3 , D50 particle size is 0.85μm, the particle size range is 1.25μm, and the friction coefficient is 0.35.

[0100] (3) The same as step (3) in Example 1, the tungsten wire finally prepared has an outer diameter of 35 μm, a diameter tolerance of ±0.35 μm, an ellipticity of ≤0.6 μm, a breaking force of 6.07 N, a tensile strength of 6055 MPa, a free circle diameter of 50 mm, and a length of 120 km.

[0101] Embodiment 4:

[0102] The same as Example 1, except that the raw material formula of the wire drawing lubricant is different:

[0103] (2) The raw materials of the wire drawing lubricant are provided according to the following formula: 20 wt % of the fluorinated graphite prepared in step (1), 5 wt % of PEG2000, 5 wt % of sodium petroleum sulfonate, 8 wt % of polyvinyl alcohol emulsion, 10 wt % of methyl cellulose, 10 wt % of ammonia water, and the balance of water.

[0104] The final prepared wire drawing lubricant has a graphite fluoride content of 20%, an ash content of 0.04%, a viscosity of 20 mPa.s, a pH value of 10.5, and a specific gravity of 1.26 g / cm3 , D50 particle size is 0.85μm, the particle size range is 1.25μm, and the friction coefficient is 0.22.

[0105] (3) The same as step (3) in Example 1, the tungsten wire finally prepared has an outer diameter of 35 μm, a diameter tolerance of ±0.3 μm, an ellipticity of ≤0.5 μm, a breaking force of 6.12 N, a tensile strength of 6035 MPa, a free circle diameter of 60 mm, and a length of 135 km.

[0106] Embodiment 5:

[0107] The method is basically the same as Example 1, except that the D50 particle size of the fluorinated graphite prepared in step (1) is 5 μm, and the particle size range is 1.2 μm.

[0108] The final prepared wire drawing lubricant has a graphite fluoride content of 18%, an ash content of 0.05%, a viscosity of 15 mPa.s, a pH value of 10, and a specific gravity of 1.32 g / cm 3 , D50 particle size is 5μm, the particle size range is 1.2μm, and the friction coefficient is 0.39.

[0109] (3) The same as step (3) in Example 1, the tungsten wire finally prepared has an outer diameter of 35 μm, a diameter tolerance of ±0.3 μm, an ellipticity of ≤0.5 μm, a breaking force of 5.95 N, a tensile strength of 5825 MPa, a free circle diameter of 45 mm, and a length of 79 km.

[0110] Comparative Example 1:

[0111] The tungsten wire was drawn using commercially available graphite emulsion (purchased from Japan Black Lead Co., Ltd., product model 4B). The graphite emulsion had a graphite content of 22%, an ash content of 0.5%, a viscosity of 18 mPa.s, a pH value of 10, a specific gravity of 1.12 g / cm3, a D50 particle size of 1.1 μm, a particle size range of 2.55 μm, and a friction coefficient of 0.68.

[0112] The steps of drawing tungsten wire specifically include: using an 8-die wire drawing machine for wire drawing, the diameter of the raw tungsten wire is 80μm, and the material is tungsten lanthanum alloy; the temperature of the wire drawing die is 450℃, the temperature of the wire drawing lubricant baking furnace is 400℃, the wire drawing speed is 120m / h, and the core material of the wire drawing die is diamond polycrystalline.

[0113] The obtained tungsten wire has an outer diameter of 35 μm, a diameter tolerance of ±0.35 μm, an ellipticity of ≤0.5 μm, a breaking force of 6.05 N, a tensile strength of 5985 MPa, a free circle diameter of 60 mm, and a length of 120 km.

[0114] Comparative Example 2:

[0115] (1) Commercially available flake graphite (purchased from Qingdao Hongrunda Graphite Technology Co., Ltd., model 2000 mesh) was purified at 2400°C to prepare flake graphite; the density of the flake graphite was 1.8 g / cm 3 The ash content is 0.05%, the particle size is 0.9μm, and the extreme value of particle size is 1.5μm.

[0116] (2) The raw materials of the wire drawing lubricant are provided according to the following formula: 18 wt % of the flake graphite prepared in step (1), 1 wt % of PEG2000, 2 wt % of sodium petroleum sulfonate, 6 wt % of polyvinyl alcohol emulsion, 2 wt % of methyl cellulose, 8 wt % of ammonia water, and the balance of water.

[0117] According to the above formula, flake graphite, surfactant, part of pure water and part of ammonia water are added to a stirring kettle, the pH value is adjusted with ammonia water, and the mixture is stirred and dispersed evenly; after the microparticle dispersion and degumming requirements are met, the remaining pure water and ammonia water, binder and thickener are added, and after high-speed dispersion for 1 hour in a high-speed disperser, the mixture is added to a vibration ball mill and ball-milled for 10 hours, and then tested and sieved to obtain a wire drawing lubricant.

[0118] The final prepared wire drawing lubricant has a flake graphite content of 18%, an ash content of 0.09%, a viscosity of 16 mPa.s, a pH value of 10, and a specific gravity of 1.15 g / cm 3 , D50 particle size is 0.85μm, the particle size range is 1.25μm, and the friction coefficient is 0.79.

[0119] (3) Using the wire drawing lubricant prepared in step (2) to prepare tungsten wire, specifically comprising: using an 8-die wire drawing machine for wire drawing, the diameter of the raw tungsten wire is 80 μm, and the material is tungsten lanthanum alloy; the wire drawing die temperature is 450° C., the temperature of the wire drawing lubricant baking furnace is 400° C., the wire drawing speed is 150 m / h, and the wire drawing die core material is diamond polycrystalline.

[0120] The obtained tungsten wire has an outer diameter of 35 μm, a diameter tolerance of ±0.3 μm, an ellipticity of ≤0.5 μm, a breaking force of 6.02 N, a tensile strength of 5925 MPa, a free circle diameter of 50 mm, and a length of 100 km.

[0121] Comparative Example 3:

[0122] The same as Example 1, except that the raw material formula of the wire drawing lubricant is different:

[0123] (1) The raw materials of the wire drawing lubricant are provided according to the following formula: 18 wt % of molybdenum disulfide, 1 wt % of PEG2000, 2 wt % of sodium petroleum sulfonate, 6 wt % of polyvinyl alcohol emulsion, 2 wt % of methyl cellulose, 8 wt % of ammonia water, and the balance of water.

[0124] The final prepared wire drawing lubricant has an ash content of 0.15%, a viscosity of 15 mPa.s, a pH value of 10, and a specific gravity of 1.26 g / cm 3 , the friction coefficient is 0.66.

[0125] (2) The same as step (3) in Example 1, the tungsten wire finally prepared has an outer diameter of 35 μm, a diameter tolerance of ±0.3 μm, an ellipticity of ≤0.5 μm, a breaking force of 5.98 N, a tensile strength of 5896 MPa, a free circle diameter of 45 mm, and a length of 80 km.

[0126] The properties of the wire drawing lubricants and tungsten wires prepared in Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 1.

[0127] Table 1

[0128]

[0129] It can be seen from Examples 1-2 in Table 1 that increasing the temperature of the fluorination reaction and prolonging the reaction time can increase the density of the fluorinated graphite and reduce the impurity content.

[0130] It can be seen from Examples 1 to 5 and Comparative Examples 1 to 3 in Table 1 that the tungsten wire prepared by the wire drawing lubricant of the present application has higher breaking force and tensile strength, larger free circle diameter and length, and its comprehensive performance is significantly better than that of traditional flake graphite emulsion and imported graphite emulsion. In addition, the wire drawing lubricant of the present application can significantly increase the wire drawing speed, thereby improving the production efficiency of tungsten wire.

[0131] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0132] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A wire drawing lubricant, characterized in that: Calculated by mass percentage, the composition includes: 15% to 20% of graphite fluoride, 1% to 5% of surfactant, 5% to 8% of binder, 2% to 10% of thickener, 2% to 10% of ammonia water and 47% to 75% of water.

2. The wire drawing lubricant according to claim 1, characterized in that: The surfactant is selected from one or more of polyethylene glycol 2000 and sodium petroleum sulfonate.

3. The wire drawing lubricant according to claim 1, characterized in that: The binder is selected from polyvinyl alcohol, polyethylene glycol or cellulose ether.

4. The wire drawing lubricant according to claim 1, characterized in that: The thickener is selected from methylcellulose, hydroxypropyl methylcellulose or sodium methylcellulose.

5. The wire drawing lubricant according to any one of claims 1 to 4, characterized in that: The D50 particle size of the fluorinated graphite is 0.6 μm to 1.0 μm.

6. The wire drawing lubricant according to claim 5, characterized in that: The extreme difference of the particle size of the fluorinated graphite is 1.0 μm to 1.5 μm.

7. A method for preparing a wire drawing lubricant according to any one of claims 1 to 6, characterized in that: The steps include: Mixing graphite fluoride, a surfactant, a binder, a thickener, ammonia water and water, and dispersing them uniformly to obtain a mixture; The mixture is ball-milled to prepare the wire drawing lubricant.

8. The method for preparing a wire drawing lubricant according to claim 7, characterized in that: The fluorinated graphite is prepared by the following steps: The ultrafine particle graphite is subjected to graphitization treatment and fluorination treatment in sequence to obtain the fluorinated graphite; Optionally, the particle size of the ultrafine graphite particles is less than or equal to 1 μm.

9. The method for preparing a wire drawing lubricant according to claim 8, characterized in that: The preparation method meets at least one of the following characteristics: (1) The temperature of graphitization treatment is 2900℃~3100℃, and the holding time is 3h~5h; (2) The temperature of fluorination treatment is 600℃~650℃; (3) the fluorinating agent for fluorination treatment is selected from one or more of fluorine gas or Freon; (4) During the fluorination treatment, the gas flow rate of the fluorinating agent is 0.8m 3 / h~1.2m 3 / h; (5) The fluorination treatment time is 3h~5h.

10. Use of the wire drawing lubricant according to any one of claims 1 to 6 or the wire drawing lubricant prepared by the preparation method according to any one of claims 7 to 9 in the preparation of cutting wire drawing.

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