Environmentally friendly boron nitride lubricating rod and preparation method thereof

Abstract

The present invention discloses an environmentally friendly boron nitride lubricating rod and a preparation method thereof, which is made of the following raw materials in weight ratio: 50-80% paraffin, 20-50% hexagonal boron nitride, 0.5-3% anti-shrinkage agent, 1-5% organic borate, and 0.2-1.5% hardness enhancer. The main body of the present invention adopts smokeless fully refined paraffin, and the auxiliary agent also adopts environmentally friendly auxiliary agent. No harmful substances are volatilized during use, and it is clean and environmentally friendly. Fully refined paraffin and high-crystalline hexagonal boron nitride are used as main components. While ensuring good high-temperature lubrication performance during use, it also reduces pollution, is clean and environmentally friendly, and is particularly suitable for the field of aluminum extrusion. In addition, the lubricating rod can maintain a long service life in a harsh environment, reduce the number of times the coating is applied, save labor, improve production efficiency, and reduce production costs.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum processing lubrication, and in particular to an environmentally friendly boron nitride lubricating rod and a preparation method thereof. Background Art

[0002] Aluminum profiles are obtained by heating aluminum rods and extruding them through molds to obtain aluminum profiles of different cross-sections and specifications. The process is to first heat the aluminum rods, the raw material of the aluminum profile, to a certain temperature, put them into the extruder, and fix the mold on the machine tool. Then put the heated aluminum rods into the aluminum profile mold, heat the aluminum rods, and obtain the desired shape. In the extrusion process of aluminum profiles, lubricants are needed to reduce the friction between the profiles and the extrusion head, the wall of the extrusion barrel, the piercing needles and the surface of the mold, reduce the adhesion between them and the wear between the molds; however, due to the use of lubricants, the surface of the aluminum profiles is often contaminated, and the lubricants may flow into the center of the profiles, forming a more obvious extrusion tail; therefore, in the extrusion of aluminum profiles, non-lubricated extrusion has been used for many years; in the extrusion of pipes and hollow aluminum profiles, only the surface of the mold and the surface of the piercing needle are lubricated; in recent years, in order to extrude large and complex hard aluminum alloy profiles on extruders with limited tonnage, and also to increase the extrusion speed and obtain extruded profiles with more uniform organizational properties, countries around the world have conducted extensive research on lubricated extrusion methods. Studies have shown that lubricated extrusion can significantly reduce the extrusion pressure, increase the extrusion speed and improve the organizational properties of aluminum profiles.

[0003] Researchers believe that aluminum sticking to the machine surface is due to the reaction of the ferric oxide particle layer on the surface with high-temperature aluminum to form aluminum oxide, which then effectively adheres to more aluminum oxide in the metal flow. Therefore, ferric oxide is the cause of aluminum sticking to the tool and die. From this perspective, it can also be fully explained that during lubrication extrusion, the lubricating coating has the function of preventing the tool from directly contacting aluminum and reducing the oxidation of the contact surface with aluminum, thereby preventing aluminum sticking, reducing friction, and improving the surface quality of aluminum profiles.

[0004] Boron nitride lubricating rods are white solids used in the hot extrusion process of non-ferrous metals. They have excellent high-temperature stability and lubrication properties. They can be applied to extrusion pads, ingot barrels, shears, etc. to effectively prevent aluminum alloys from sticking to the mold. They extend the life of the extrusion pads, are easy to use, shorten maintenance time, improve production efficiency, and save costs. They emit less smoke, do not contain dangerous ingredients, and are harmless to human health. However, due to technical confidentiality and other reasons, the public patents related to boron nitride lubricating rods and their preparation methods have not been retrieved so far. Summary of the invention

[0005] In view of the current status of aluminum extrusion lubricating coating and the problems existing in the prior art, the present invention provides an environmentally friendly boron nitride lubricating rod and a preparation method thereof.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] An environmentally friendly boron nitride lubricating rod is prepared from the following raw materials in weight ratio: 50-80% paraffin wax, 20-50% hexagonal boron nitride, 0.5-3% anti-cratering agent, 1-5% organic borate ester and 0.2-1.5% hardness enhancer.

[0008] Furthermore, the paraffin wax is fully refined smokeless paraffin wax, and its brand is 58#, 60#, 62# or 64#.

[0009] Furthermore, the hexagonal boron nitride is highly crystalline hexagonal boron nitride, with a particle size between 20.0 μm and 150.0 μm and a purity of more than 95%.

[0010] Furthermore, the anti-cratering agent is any one of BYK-363, JH-3667 or JSA-BO.

[0011] Furthermore, the hardness enhancer is any one of stearic acid, oleic acid or palmitic acid.

[0012] Furthermore, the preparation method of the environmentally friendly boron nitride lubricating rod comprises the following steps: firstly, heating the paraffin wax to make it completely melted, then adding hexagonal boron nitride, organic borate and hardness enhancer and stirring evenly (rotating speed 2000r / min), finally adding anti-shrinkage agent, continuing to stir evenly and then injecting into the mold, cooling at room temperature for 24 hours and then opening the mold to obtain the environmentally friendly boron nitride lubricating rod.

[0013] Paraffin products are classified by type, including semi-refined paraffin, fully refined paraffin, paraffin for food processing, microcrystalline wax and various special waxes. Fully refined paraffin refers to the product obtained by using oil-containing wax as raw material, deoiling by sweating or solvent, and then refining by white clay. Fully refined paraffin has the appearance of white solid, divided into two forms: block and granular products. Its product characteristics are high melting point, low oil content, no adhesion at room temperature, no greasy feeling, good waterproof, moisture-proof and electrical insulation properties. At the same time, due to the deep degree of refining, the content of polycyclic aromatic hydrocarbons is relatively low. Therefore, it has good chemical stability, light and thermal stability, strong toughness, good plasticity, white color, no mechanical impurities and moisture, no odor, and is an ideal matrix material, widely used in various fields of production and life.

[0014] Hexagonal boron nitride, especially high-crystallinity hexagonal boron nitride, has good high-temperature lubrication properties. The layered structure of BN is easy to move, so this material can be used as a solid lubricant. When the temperature is less than 600°C, the friction coefficient of graphite is smaller than that of BN. During the period of 600-800°C, due to the oxidation of graphite, its friction coefficient increases sharply; while in this temperature range, the friction coefficient of BN does not increase much, which reflects the advantages of BN. These characteristics determine that it is an ideal lubricating material in the metal processing process, which helps to minimize the surface defects of metal products, make it easier to demold, increase the service life of molds / dies, and reduce the time required for mold cleaning.

[0015] However, in the actual application process, a large number of pores will be generated during the combination of molten paraffin and boron nitride powder, which will cause the strength of paraffin to weaken after solidification, and then cause the lubricating rod to be unevenly applied during subsequent use, and defects will be generated on the coating surface, affecting the lubrication effect and service life. In the present invention, any one of BYK-363, JH-3667 or JSA-BO is used as an anti-shrinkage crater agent, which are all organic siloxane compounds, have good compatibility with the paraffin matrix, are not separated by cooling, are non-toxic and harmless, and do not decompose at 200°C, and do not produce toxic and harmful gases, and belong to an environmentally friendly anti-shrinkage crater agent. At the same time, stearic acid, soft ester acid or oleic acid are used as reinforcing agents for paraffin in the present invention, and they all belong to long-chain fatty acids, which are a commonly used tackifier and hardness enhancer, which can increase the viscosity of paraffin, making paraffin more suitable for some specific industrial applications. When long-chain fatty acids are mixed with paraffin, they will form intermolecular forces between the paraffin molecules, forming a network structure, thereby increasing the intermolecular distance and intermolecular friction of the entire mixed system. The amount of long-chain fatty acids added is related to factors such as the type and quality of paraffin. The compatibility between different paraffins and long-chain fatty acids may also be different, and needs to be adjusted and selected according to specific circumstances. In addition, organic borate has good anti-friction and anti-wear properties, good corrosion resistance, antioxidant properties, and oil solubility. It is an excellent anti-friction and anti-wear promoter. It can be used not only as a lubricant additive, but also as a polymer additive, gasoline additive, bactericide, and flame retardant.

[0016] Therefore, in the preparation process of the above-mentioned boron nitride lubricating rod, we use fully refined paraffin wax as the base material of the lubricating rod, highly crystalline hexagonal boron nitride as the main material for high-temperature lubrication, and with the help of appropriate types and amounts of additives, we have prepared a boron nitride lubricating rod with excellent performance. Among them, organic siloxanes (BYK-363, JH-3667 or JSA-BO) are used as anti-shrinkage agents, organic borate esters are used as anti-friction and anti-wear promoters, and long-chain fatty acids (stearic acid, soft ester acid or oleic acid) are used as hardness enhancers. They have good compatibility with the matrix, strong operability, and no phase separation occurs during the cooling process. In addition, the chain segments will be entangled between the additives and the matrix and between the additives. The synergistic effect between them makes the hexagonal boron nitride firmly fixed in the paraffin wax, greatly enhancing the bonding strength between the paraffin wax and the hexagonal boron nitride, so that the prepared boron nitride lubricating rod has the advantages of high density, good lubrication performance, good strength, and long service life.

[0017] Beneficial effects of the present invention: Compared with the existing lubricating coating, the present invention uses fully refined paraffin wax and highly crystalline hexagonal boron nitride as the main materials, which not only ensures good high-temperature lubrication performance during use, but also reduces pollution, is clean and environmentally friendly, and is particularly suitable for the field of aluminum processing. In addition, the lubricating rod can also maintain a long service life in a harsh environment, reduce the number of times the coating is applied, save labor, improve production efficiency, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a physical picture of the boron nitride lubricating rod prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention, and those skilled in the art in this field can make some non-essential improvements and adjustments based on the content of the above invention.

[0020] Example 1

[0021] The environmentally friendly boron nitride lubricating stick of this embodiment is made of the following raw materials in the following weight ratio: 61% paraffin wax, 30% hexagonal boron nitride, 3% BYK-363, 5% organic borate and 1% stearic acid.

[0022] The preparation method of the environmentally friendly boron nitride lubricating stick of this embodiment is as follows:

[0023] First, heat the paraffin (58#) to make it completely melted, then add hexagonal boron nitride (20μm), BYK-363, and stearic acid and stir evenly (speed 2000r / min), finally add organic borate, continue to stir evenly and inject into the mold, cool at room temperature for 24 hours and then open the mold to obtain the environmentally friendly boron nitride lubricating rod.

[0024] Example 2

[0025] The environmentally friendly boron nitride lubricating stick of this embodiment is made of the following raw materials in the following weight ratio: 70% paraffin, 25% hexagonal boron nitride, 2% JH-3667, 2% organic borate and 1% soft acid.

[0026] The preparation method of the environmentally friendly boron nitride lubricating stick of this embodiment is as follows:

[0027] First, heat the paraffin (62#) to make it completely melted, then add hexagonal boron nitride (100μm), JH-3667, and palmitic acid and stir evenly (speed 2000r / min), finally add organic borate, continue to stir evenly and inject into the mold, cool at room temperature for 24 hours and then open the mold to obtain the environmentally friendly boron nitride lubricating rod.

[0028] Example 3

[0029] The environmentally friendly boron nitride lubricating stick of this embodiment is made of the following raw materials in the following weight ratio: 80% paraffin wax, 15% hexagonal boron nitride, 2% JSA-BO, 1% organic borate and 2% oleic acid.

[0030] The preparation method of the environmentally friendly boron nitride lubricating stick of this embodiment is as follows:

[0031] First, heat the paraffin (64#) to make it completely melted, then add hexagonal boron nitride (150μm), JSA-BO, and oleic acid and stir evenly (speed 2000r / min), finally add organic borate, continue to stir evenly and inject into the mold, cool at room temperature for 24 hours and then open the mold to obtain the environmentally friendly boron nitride lubricating rod.

[0032] Comparative Example 1 (without adding anti-cratering agent on the basis of Example 1)

[0033] The environmentally friendly boron nitride lubricating stick of this comparative example is made of the following raw materials in the following weight ratio: 64% paraffin wax, 30% hexagonal boron nitride, 5% organic borate and 1% stearic acid.

[0034] The preparation method of the environmentally friendly boron nitride lubricating stick of this embodiment is as follows:

[0035] First, heat paraffin (58#) to make it completely melted, then add hexagonal boron nitride (20μm), organic borate and stearic acid, stir evenly (speed 2000r / min), and then inject into the mold. After cooling at room temperature for 24 hours, open the mold to obtain the environmentally friendly boron nitride lubricating rod.

[0036] Comparative Example 2 (without adding hardness enhancer based on Example 1)

[0037] The environmentally friendly boron nitride lubricating stick of this embodiment is made of the following raw materials in the following weight ratio: 62% paraffin wax, 30% hexagonal boron nitride, 3% BYK-363 and 5% organic borate.

[0038] The preparation method of the environmentally friendly boron nitride lubricating stick of this embodiment is as follows:

[0039] First, heat the paraffin (58#) to make it completely melted, then add hexagonal boron nitride (20μm) and BYK-363 and stir evenly (speed 2000r / min), finally add organic borate, continue to stir evenly and inject into the mold, cool at room temperature for 24 hours and then open the mold to obtain the environmentally friendly boron nitride lubricating rod.

[0040] Comparative Example 3 (Based on Example 1, without adding organic borate)

[0041] The environmentally friendly boron nitride lubricating stick of this embodiment is made of the following raw materials in the following weight ratio: 66% paraffin, 30% hexagonal boron nitride, 3% BYK-363 and 1% stearic acid.

[0042] The preparation method of the environmentally friendly boron nitride lubricating stick of this embodiment is as follows:

[0043] First, heat the paraffin (58#) to make it completely melted, then add hexagonal boron nitride (20μm) and BYK-363 and stir evenly (speed 2000r / min), finally add stearic acid, continue to stir evenly and inject into the mold, cool at room temperature for 24h and then open the mold to obtain the environmentally friendly boron nitride lubricating rod.

[0044] The wax sticks obtained from the above three embodiments and three comparative examples were subjected to comparative tests on the extrusion head of an aluminum extrusion workshop, and comparative tests were conducted on the coating friction coefficient, number of uses, surface finish of aluminum profiles, etc. The specific experimental comparison results are shown in the following table.

[0045]

[0046] The above comparative tests show that under the same experimental conditions, the boron nitride lubricating rod obtained in the embodiment has a smaller needle penetration, a lower friction coefficient, a longer service life and better surface finish.

[0047] The basic principles and main features of the present invention as well as the advantages of the present invention are shown and described above.

[0048] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An environmentally friendly boron nitride lubricating stick, characterized in that: The raw materials include the following weight percentages: paraffin wax 50% to 80%, hexagonal boron nitride 20% to 50%, anti-shrinkage agent 0.5% to 3%, organic borate 1% to 5% and hardness enhancer 0.2% to 1.5%; The paraffin wax is any one of 58#, 60#, 62# or 64# fully refined smokeless paraffin wax; The hexagonal boron nitride is highly crystalline hexagonal boron nitride, with a particle size between 20.0 μm and 150.0 μm and a purity of more than 95%; The anti-cratering agent is any one of BYK-363, JH-3667 or JSA-BO.

2. The environmentally friendly boron nitride lubricating stick according to claim 1, characterized in that: The hardness enhancer is any one of stearic acid, oleic acid or stearic acid.

3. The method for preparing the environmentally friendly boron nitride lubricating stick according to claim 1 or 2, characterized in that The steps are as follows: first, heat the paraffin to make it completely melted, then add hexagonal boron nitride, organic borate and hardness enhancer and stir evenly, finally add anti-shrinkage agent, stir evenly and inject it into the mold while hot, cool to room temperature and completely solidify it before opening the mold to obtain an environmentally friendly boron nitride lubricating rod.

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