Preparation method of rolling oil additive

Abstract

The invention discloses a preparation method of a rolling oil additive, which comprises the following steps: fatty acid methyl ester is added into a reactor, and is heated to a preset temperature, the content of methyl oleate in the fatty acid methyl ester is more than 70.0%, and the content of methyl linoleate is more than 10.0% and less than 20.0%; sulfur is added into the reactor in three times, the reactor is heated to a preset temperature, heat preservation is carried out, a vulcanization reaction is carried out, and the mass of sulfur accounts for 25.0%-27.0% of the mass of fatty acid methyl ester; oleylamine is added into the reactor, heat preservation is carried out, a neutralization reaction is carried out, and the mass of the oleylamine accounts for 3.0%-5.0% of the mass of the fatty acid methyl ester; and carrying out vacuum operation on the reactor to remove residual hydrogen sulfide, and filtering to obtain the rolling oil additive. By means of the technical scheme, the extreme pressure property and stability of the product are guaranteed, the free sulfur content and smell of the product can be reduced, generation of by-products is reduced, and the product applied to rolling oil is high in extreme pressure, corrosion resistance and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating compositions, and in particular to a method for preparing a rolling oil additive. Background Art

[0002] Rolling is a metalworking process that involves the plastic deformation of a metal workpiece by means of rotating rollers. During rolling, the rollers and workpiece squeeze and slide against each other, generating friction and wear. Rolling oil improves the lubrication between the rollers and the workpiece, reducing friction and increasing rolling efficiency. Extreme pressure properties are a key indicator of rolling oil quality. Furthermore, rolling oils should possess good corrosion resistance and thermal stability under high temperatures and pressures.

[0003] Sulfurized fatty acid methyl esters are a commonly used extreme pressure additive in rolling oils, exhibiting excellent extreme pressure properties. Their synthesis routes primarily include the sulfur-chloride route, the sulfur route, and the hydrogen sulfide route. The sulfur-chloride route has a complex production process, and due to the formation of hydrogen chloride, the resulting product has poor corrosion resistance. The hydrogen sulfide route produces products with a lighter color and better extreme pressure properties, but places extremely high demands on production equipment and reduces production safety. The commonly used sulfur route, on the other hand, has a simpler production process, but existing processes are prone to side reactions, resulting in poor extreme pressure properties, making it difficult to meet the extreme pressure requirements of rolling oils. Furthermore, the product has a high acid value, making its use in rolling oils prone to corrosion of workpieces and machine tools.

[0004] Currently, existing technologies mostly update the synthesis process of sulfided fatty acid methyl esters from the technical route, and rarely disclose innovations in the commonly used sulfur route process, especially sulfided fatty acid methyl esters with excellent extreme pressure performance and suitable for use in rolling oils. Summary of the Invention

[0005] To address the above issues, the present invention provides a method for preparing a rolling oil additive. By balancing the contents of methyl linoleate and methyl oleate in fatty acid methyl esters, the extreme pressure and stability of the product are ensured. The extreme pressure properties of the product are also maintained by post-treating the reaction process with oleylamine, which can reduce the free sulfur content and odor of the product. Furthermore, by rationally designing the neutralization reaction temperature, the acid value of the product is neutralized without affecting the extreme pressure performance. Furthermore, by batch feeding, i.e., controlling process parameters, the formation of byproducts is reduced. These multiple factors result in a special rolling oil additive product with high extreme pressure, corrosion resistance, and stability.

[0006] To achieve the above object, the present invention provides a method for preparing a rolling oil additive, comprising:

[0007] Adding a preset amount of fatty acid methyl ester to a reactor and heating it to a preset temperature, wherein the fatty acid methyl ester has an oleate methyl ester content greater than 70.0% and a linoleate methyl ester content less than 10.0% and less than 20.0%;

[0008] Adding sulfur into the reactor in three portions, heating the reactor to a preset temperature and keeping the temperature for a preset time to perform a sulfurization reaction, wherein the mass of the sulfur is 25.0% to 27.0% of the fatty acid methyl ester;

[0009] Adding oleylamine to the reactor and keeping it warm for a preset time to carry out a neutralization reaction, wherein the mass of the oleylamine is 3.0%-5.0% of the fatty acid methyl ester;

[0010] The reactor is vacuum operated to remove residual hydrogen sulfide, and the rolling oil additive is obtained by filtration.

[0011] In the above technical solution, preferably, the fatty acid methyl ester is added to the reactor and then heated to 140°C.

[0012] In the above technical solution, preferably, the interval between the addition of the sulfur is 1 hour, and the temperature in the system is ensured not to exceed 145° C. during the addition of the sulfur.

[0013] In the above technical solution, preferably, after the sulfur is added to the reactor, the temperature is raised to 170° C. and kept warm for 5 hours to carry out the sulfurization reaction.

[0014] In the above technical solution, preferably, the temperature of the oleylamine is lowered to 140° C. before being added to the reactor, and the temperature is kept constant for 2 hours after the addition of the oleylamine.

[0015] In the above technical solution, preferably, the vacuum operation includes air vacuum operation and nitrogen protection vacuum operation, and the gas flow rate of the vacuum operation is 1m 3 / h, and the vacuum degree is maintained at -0.05Mpa.

[0016] In the above technical solution, preferably, after the reactor is subjected to vacuum operation for 2 hours, the material in the reactor is filtered to obtain the rolling oil additive.

[0017] Compared with existing technologies, the present invention offers the following advantages: By balancing the contents of methyl linoleate and methyl oleate in fatty acid methyl esters, the extreme pressure and stability of the product are ensured; by post-treating the reaction process with oleylamine, the extreme pressure of the product is enhanced, reducing the free sulfur content and odor of the product; and by rationally designing the neutralization reaction temperature, the acid value of the product is neutralized without affecting its extreme pressure performance. Furthermore, by batching, i.e., controlling process parameters, the formation of byproducts is reduced. These multiple factors result in a rolling oil additive product with high extreme pressure, corrosion resistance, and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1The present invention is a schematic flow chart of a method for preparing a rolling oil additive disclosed in one embodiment of the present invention. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0020] The present invention is described in further detail below with reference to the accompanying drawings:

[0021] like Figure 1 As shown, a method for preparing a rolling oil additive according to the present invention comprises:

[0022] Adding a preset amount of fatty acid methyl ester to the reactor and heating it to a preset temperature, wherein the oleic acid methyl ester content of the fatty acid methyl ester is greater than 70.0%, and the linoleic acid methyl ester content is less than 10.0% and less than 20.0%;

[0023] Adding sulfur to the reactor in three portions, heating the reactor to a preset temperature and maintaining the temperature for a preset time to carry out a sulfurization reaction, wherein the mass of the sulfur is 25.0% to 27.0% of the fatty acid methyl ester;

[0024] Adding oleylamine to the reactor and keeping it warm for a preset time for neutralization reaction, wherein the mass of oleylamine is 3.0%-5.0% of the fatty acid methyl ester;

[0025] The reactor is vacuum operated to remove residual hydrogen sulfide, and the rolling oil additive is obtained by filtration.

[0026] In this embodiment, the extreme pressure and stability of the product are ensured by balancing the contents of linoleic acid methyl ester and oleic acid methyl ester in fatty acid methyl ester. The extreme pressure of the product is ensured by post-treating the reaction process with oleylamine, and the free sulfur content and odor of the product can be reduced. At the same time, by rationally designing the neutralization reaction temperature, the acid value of the product is ensured to be neutralized without affecting the extreme pressure performance of the product. By batch feeding, that is, process parameter control, the generation of by-products is reduced, and the product is applied to a special additive product for rolling oil with high extreme pressure, corrosion resistance and stability.

[0027] Specifically, if the methyl linoleate content is too low, the unsaturation level is low, and it cannot fully react with sulfur, resulting in a product with high free sulfur and poor stability. If the methyl linoleate content is too high, cross-linked sulfides and active sulfur compounds such as trisulfides and tetrasulfides will convert into monosulfides and disulfides, impairing the extreme pressure properties of the product. Therefore, by limiting the content of methyl linoleate and methyl oleate in fatty acid methyl esters, the extreme pressure properties and stability of the product can be guaranteed.

[0028] The post-treatment with oleylamine not only neutralizes the acidic substances in the system and reduces the acid value of the product, but also allows the unsaturated double bonds in the oleylamine to continue reacting with free sulfur, controlling the free sulfur content and odor of the product and improving product stability. Furthermore, the low neutralization temperature prevents the conversion of cross-linking substances and polysulfides into monosulfides and disulfides, ensuring the extreme pressure properties of the product.

[0029] In the above embodiment, preferably, the fatty acid methyl ester is added to the reactor and then heated to 140° C., and sulfur is added at 140° C. to carry out a sulfurization reaction.

[0030] In the above embodiment, preferably, the interval between the additions of sulfur is 1 hour, and the temperature in the system is ensured not to exceed 145° C. during the addition of sulfur.

[0031] Specifically, the process condition of adding sulfur in batches can control the occurrence of side reactions and reduce the generation of by-products such as mercaptans.

[0032] In the above embodiment, preferably, after sulfur is added to the reactor, the temperature is raised to 170° C. and kept at this temperature for 5 hours to carry out the sulfurization reaction.

[0033] In the above embodiment, preferably, the temperature is lowered to 140° C. before oleylamine is added to the reactor, and the temperature is kept to react for 2 hours after the addition of oleylamine.

[0034] Specifically, if oleylamine is added under the reaction condition of 170°C, the cross-linking substances and polysulfides in the system are converted into monosulfides and disulfides under the high temperature and catalytic action, and the extreme pressure performance of the product is poor. Therefore, the organic amine temperature is graded to react, and the reactor is cooled to 140°C before adding oleylamine. Adding organic amine at an appropriate temperature can prevent the cross-linking substances in the system from breaking and generate macromolecular substances, which can improve the extreme pressure of the product, reduce the acid value of the product, and control the free sulfur content and odor of the product.

[0035] In the above embodiment, preferably, the vacuum operation includes air vacuum operation and nitrogen protection vacuum operation, and the gas flow rate of the vacuum operation is 1m 3 / h, and the vacuum degree is maintained at -0.05Mpa.

[0036] In the above embodiment, preferably, after the reactor is subjected to vacuum operation for 2 hours, the material in the reactor is filtered to obtain the rolling oil additive.

[0037] Specifically, during the vacuum operation, the residual hydrogen sulfide in the reactor can be discharged. Continuing the vacuum operation for 2 hours can ensure that all hydrogen sulfide is discharged before the reaction is completed, thereby ensuring the stability of the product.

[0038] According to the preparation method of the rolling oil additive disclosed in the above embodiment, the preparation method and the characteristics of the product are described below through examples.

[0039] Example 1:

[0040] 160 g of fatty acid methyl ester (specific composition: 75.0% methyl oleate; 15.0% methyl linoleate, and the rest are mainly saturated fatty acid methyl esters such as methyl hexadecanoate and methyl octadecanoate, and a small amount of methyl linolenate) was added to a 500 mL flask, and the temperature was raised to 140°C. 42 g of raw sulfur was added to the fatty acid methyl ester three times, each time interval was 1 hour, and the system temperature was ensured not to exceed 145°C. After the addition of sulfur, the system was heated to 170°C and kept warm for 5 hours. After the reaction was completed, the temperature was lowered to 140°C, 6.5 g of oleylamine was added, and the reaction was kept warm for 2 hours. After the reaction was completed, air and vacuum were turned on (air flow rate 1m 3 / h, vacuum degree -0.05MPa), and treated for 2h to remove hydrogen sulfide, and then filtered to obtain the finished product.

[0041] Comparative Example 1:

[0042] 160 g of fatty acid methyl ester (specific composition: 35.0% methyl oleate; 45.0% methyl linoleate, and the rest are mainly saturated fatty acid methyl esters such as methyl hexadecanoate and methyl octadecanoate, and a small amount of methyl linolenate) was added to a 500 mL flask, and the temperature was raised to 140°C. 42 g of raw sulfur was added to the fatty acid methyl ester three times, each time interval was 1 hour, and the system temperature was ensured not to exceed 145°C. After the addition of sulfur, the system was heated to 170°C and kept warm for 5 hours. After the reaction was completed, the temperature was lowered to 140°C, 6.5 g of oleylamine was added, and the reaction was kept warm for 2 hours. After the reaction was completed, air and vacuum were turned on (air flow rate 1m 3 / h, vacuum degree -0.05MPa), and treated for 2h to remove hydrogen sulfide, and then filtered to obtain the finished product.

[0043] Comparative Example 2:

[0044] 160 g of fatty acid methyl ester (specific composition: 60.0% methyl oleate; 10.0% methyl linoleate, and the rest are mainly saturated fatty acid methyl esters such as methyl hexadecanoate and methyl octadecanoate, and a small amount of methyl linolenate) was added to a 500 mL flask, and the temperature was raised to 140°C. 42 g of raw sulfur was added to the fatty acid methyl ester three times, each time interval was 1 hour, and the system temperature was ensured not to exceed 145°C. After the addition of sulfur, the system was heated to 170°C and kept warm for 5 hours. After the reaction was completed, the temperature was lowered to 140°C, 6.5 g of oleylamine was added, and the reaction was kept warm for 2 hours. After the reaction was completed, air and vacuum were turned on (air flow rate 1m 3 / h, vacuum degree -0.05MPa), and treated for 2h to remove hydrogen sulfide, and then filtered to obtain the finished product.

[0045] Comparative Example 3:

[0046] 160 g of fatty acid methyl ester (specific composition: 75.0% methyl oleate; 15.0% methyl linoleate, the rest mainly saturated fatty acid methyl esters such as methyl hexadecanoate and methyl octadecanoate and a small amount of methyl linolenate) was added to a 500 mL flask, and the temperature was raised to 140°C. 42 g of raw sulfur was added to the fatty acid methyl ester in three times, each time interval was 1 hour, and the system temperature was ensured not to exceed 145°C. After the sulfur was added, the system was heated to 170°C and kept incubated for 5 hours. After the reaction was completed, the temperature was lowered to 140°C, and air and vacuum were turned on (air flow rate 1m 3 / h, vacuum degree -0.05MPa), and treated for 2h to remove hydrogen sulfide, and then filtered to obtain the finished product.

[0047] Comparative Example 4:

[0048] In a 500mL flask, 160g of fatty acid methyl ester (specific composition: 75.0% methyl oleate; 15.0% methyl linoleate, and the rest are mainly saturated fatty acid methyl esters such as methyl hexadecanoate and methyl octadecanoate, and a small amount of methyl linolenate) was added, 6.5g of oleylamine was added, and the temperature was raised to 140°C. 42g of raw sulfur was added to the fatty acid methyl ester three times, each time interval was 1h, and the system temperature was ensured not to exceed 145°C. After the sulfur was added, the system was heated to 170°C and kept in reaction for 5h. After the reaction was completed, the temperature was lowered to 140°C, and nitrogen and vacuum were turned on (nitrogen flow rate 1m 3 / h, vacuum degree -0.05MPa), and treated for 2h to remove hydrogen sulfide, and then filtered to obtain the finished product.

[0049] Comparative Example 5:

[0050] 160 g of fatty acid methyl ester (specific composition: 75.0% methyl oleate; 15.0% methyl linoleate, and the rest are mainly saturated fatty acid methyl esters such as methyl hexadecanoate and methyl octadecanoate, and a small amount of methyl linolenate) was added to a 500 mL flask, and the temperature was raised to 140°C. 30 g of raw sulfur was added to the fatty acid methyl ester three times, each time interval was 1 hour, and the system temperature was ensured not to exceed 145°C. After the addition of sulfur, the system was heated to 170°C and kept warm for 5 hours. After the reaction was completed, the temperature was lowered to 140°C, 6.5 g of oleylamine was added, and the reaction was kept warm for 2 hours. After the insulation reaction was completed, nitrogen and vacuum were turned on (nitrogen flow rate 1m 3 / h, vacuum degree -0.05MPa), and treated for 2h to remove hydrogen sulfide, and then filtered to obtain the finished product.

[0051] Comparative Example 6:

[0052] Add 160g of fatty acid methyl ester (specific composition: 75.0% methyl oleate; 15.0% methyl linoleate, the rest are mainly saturated fatty acid methyl esters such as methyl hexadecanoate and methyl octadecanoate, and a small amount of methyl linolenate) into a 500mL flask and heat it to 170°C. Add 42g of raw sulfur to the fatty acid methyl ester at once. After adding sulfur, keep the system warm for 5h. After the reaction is completed, cool to 140°C, add 6.5g of oleylamine, and keep the temperature for 2h. After the insulation reaction is completed, turn on nitrogen and vacuum (nitrogen flow rate 1m 3 / h, vacuum degree -0.05MPa), and treated for 2h to remove hydrogen sulfide, and then filtered to obtain the finished product.

[0053] Comparative Example 7:

[0054] Add 160g of fatty acid methyl ester (specific composition: 75.0% methyl oleate; 15.0% methyl linoleate, and the rest are mainly saturated fatty acid methyl esters such as methyl hexadecanoate and methyl octadecanoate, and a small amount of methyl linolenate) into a 500mL flask, heat it to 140°C, add 42g of raw sulfur to the fatty acid methyl ester three times, each time interval is 1h, and ensure that the system temperature does not exceed 145°C. After adding sulfur, heat the system to 200°C and keep it warm for 5h. After the reaction is completed, cool it to 140°C, add 6.5g of oleylamine, and keep it warm for 2h. After the insulation reaction is completed, open air and vacuum (air flow rate 1m 3 / h, vacuum degree -0.05MPa), and treated for 2h to remove hydrogen sulfide, and then filtered to obtain the finished product.

[0055] The products in the examples were tested for physical and chemical properties, including sulfur content, free sulfur content, and acid value. The samples were also mixed with rolling oil at a 5.0% dosage and evaluated for extreme pressure, thermal stability, and oxidation resistance. The specific testing methods were as follows: extreme pressure was measured according to the "Determination of Anti-Wear Properties of Lubricating Oils (Four-Ball Method)" SH / T 0189-92; thermal stability was tested according to the "Determination of the Initial Thermal Decomposition Temperature of Lubricants (Thermogravimetric Analysis)." The experimental data are summarized in the following table:

[0056] Table 1. Test results of physical and chemical indicators of samples

[0057]

[0058] Compared with Comparative Example 1, the content of linoleic acid methyl ester in the raw fatty acid methyl ester of Comparative Example 1 is increased, and the unsaturated double bonds that can react with sulfur are increased, so the free sulfur content is reduced. However, with the increase of unsaturation, the trisulfide and tetrasulfide in the product are gradually converted into monosulfide and disulfide. In addition, linoleic acid methyl ester contains two unsaturated double bonds, both of which can undergo sulfurization reaction. Due to the steric effect, the content of cross-linked products is reduced, which also causes the PB value of the product to decrease and the extreme pressure properties to deteriorate.

[0059] Compared with Comparative Example 2, Example 1 shows that the content of linoleic acid methyl ester in the raw fatty acid methyl ester of Comparative Example 2 is reduced, and its free sulfur content is increased. The product is prone to the risk of sulfur precipitation during storage. In addition, the reduced sulfur content of the product also affects the extreme pressure properties of the product.

[0060] Comparing Example 1 with Comparative Example 3, which did not use oleylamine treatment, it can be seen that the free sulfur content and acid value of Example 1 are significantly increased. This is because oleylamine can react with acidic substances to reduce the acid value of the product, and the unsaturated double bond in oleylamine can react with free sulfur to reduce the free sulfur content of the product. During this process, the double bond of oleylamine breaks, connecting with the fatty acid methyl ester through the sulfur. The amino group at the other end connects with the acidic group to form a macromolecular substance, which improves the extreme pressure properties of the product.

[0061] Compared with Comparative Example 4, Example 1 shows that oleylamine in Comparative Example 4 is added in advance during the high-temperature reaction stage. Under the action of high temperature and oleylamine catalyst, the cross-linking substances and polysulfides in the system are converted into monosulfides and disulfides, and the extreme pressure of the product is greatly reduced. During the chain scission process, the system releases more hydrogen sulfide, resulting in a low sulfur content in the product.

[0062] Compared with Comparative Example 5, Example 1 has a lower sulfur feed rate in Comparative Example 5, which leads to a lower sulfur content in the product and a lower polysulfide content, which will inevitably cause the extreme pressure properties of the product to deteriorate.

[0063] Compared with Comparative Example 6, Example 1 shows that the sulfur in Comparative Example 6 is added all at once and directly reacted at high temperature, which increases the side reactions of the product and generates more by-products such as mercaptans, resulting in poor thermal stability of the product.

[0064] Compared with Comparative Example 7, Example 1 shows that the vulcanization reaction temperature of Comparative Example 7 is increased to 200° C., and chain scission occurs due to excessively high temperature. Sulfur is released from the system in the form of hydrogen sulfide, etc., and the sulfur content of the product is low. After the reaction is completed, structural analysis is performed, and no cross-linked substances are left in the system. The extreme pressure properties of the product are poor.

[0065] From the above comparison, it can be seen that the present invention selects appropriate raw materials and is equipped with the best production process to prepare sulfurized methyl oleate products with excellent properties, which are suitable for rolling oils with high requirements for extreme pressure, corrosion resistance and thermal stability.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a rolling oil additive, characterized in that: include: Adding a preset amount of fatty acid methyl ester to a reactor and heating it to a preset temperature, wherein the fatty acid methyl ester has an oleate methyl ester content greater than 70.0% and a linoleate methyl ester content less than 10.0% and less than 20.0%; Adding sulfur into the reactor in three portions, heating the reactor to a preset temperature and keeping the temperature for a preset time to perform a sulfurization reaction, wherein the mass of the sulfur is 25.0%-27.0% of the fatty acid methyl ester; Adding oleylamine to the reactor and keeping it warm for a preset time to carry out a neutralization reaction, wherein the mass of the oleylamine is 3.0%-5.0% of the fatty acid methyl ester; The reactor is vacuum operated to remove residual hydrogen sulfide, and the rolling oil additive is obtained by filtration.

2. The method for preparing the rolling oil additive according to claim 1, characterized in that: The fatty acid methyl ester was added into the reactor and then heated to 140°C.

3. The method for preparing the rolling oil additive according to claim 2, characterized in that: The interval between the addition of the sulfur is 1 hour, and the temperature in the system is ensured not to exceed 145° C. during the addition of the sulfur.

4. The method for preparing the rolling oil additive according to claim 3, characterized in that: After the sulfur is added to the reactor, the temperature is raised to 170° C. and kept at this temperature for 5 hours to carry out a sulfurization reaction.

5. The method for preparing the rolling oil additive according to claim 4, characterized in that: The temperature of the reactor was lowered to 140° C. before the oleylamine was added, and the reactor was kept warm for 2 hours after the oleylamine was added.

6. The method for preparing the rolling oil additive according to claim 5, characterized in that: The vacuum operation includes air vacuum operation and nitrogen protection vacuum operation, and the gas flow rate of the vacuum operation is 1m 3 / h, and the vacuum degree is maintained at -0.05MPa.

7. The method for preparing the rolling oil additive according to claim 6, characterized in that: After the reactor was subjected to vacuum operation for 2 hours, the material in the reactor was filtered to obtain the rolling oil additive.

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