Environment-friendly degradable gear lubricant as well as preparation method and application thereof

Abstract

The invention relates to an environment-friendly degradable gear lubricant as well as a preparation method and application thereof, in particular to an environment-friendly degradable gear lubricant which is prepared from the following components in percentage by weight: 50-60% of base oil, 15-25% of an additive, 23-38% of modified castor oil, 5-10% of an antioxidant and 5-8% of a tackifier, the base oil is prepared from pentaerythritol ester, butylene adipate, butylene terephthalate and a catalyst, and the mass ratio of the pentaerythritol ester to the butylene adipate to the butylene terephthalate is (1.2 to 2.5) to (3.1 to 4.5) to (2 to 3). The vegetable oil biological lubricant can ensure environmental friendliness and degradability while realizing lubrication, and has all characteristics required by lubricating oil, including high viscosity index, low volatility and good lubricity.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricants, and more particularly to an environmentally friendly and degradable gear lubricant and a preparation method and application thereof. Background Art

[0002] At present, the main structure of lubricating oil is still mineral oil, and the amount of mineral oil leaked or discharged into the environment is still huge. Mineral oil lubricants have poor biodegradability. When they are scattered on the ground or enter the water, they will gradually accumulate to form hydrocarbons that are not easy to degrade, directly polluting the soil and water. In addition, waste mineral oil contains volatile benzene series, polycyclic aromatic hydrocarbons and other organic pollutants and a small amount of heavy metals, and is classified as HW08 hazardous waste with toxicity and flammability. Therefore, the leakage of lubricating grease and the informal disposal or disorderly discharge of waste lubricating grease will bring great harm to the ecological environment and people's health.

[0003] At present, the definition of biodegradable lubricants that are widely recognized in the industry is: "According to the OECD 301 or ASTM D5864 test standards, after mixing the test lubricant sample with the test solution, after a 28-day decomposition process, more than 60% of the lubricant sample is degraded, and the residues are harmless substances such as water, carbon dioxide, and microorganisms." Since the base oil accounts for 80% to 90% or even higher in lubricants, the biodegradability of lubricants is basically determined by the biodegradability of the base oil used.

[0004] Additives will affect the biodegradability of lubricants to a certain extent, but as long as they are non-carcinogenic, do not contain chlorine, nitrites and heavy metals, and have low toxicity, their impact on biodegradability is much less than that of base oil. Therefore, biodegradable base oil is a key factor in the development of biodegradable lubricants. Summary of the invention

[0005] The present invention provides an environmentally friendly and degradable gear lubricant, a preparation method and application thereof. The vegetable oil biolubricant can achieve lubrication while ensuring environmental friendliness and degradability. It has all the properties required as a lubricant, including a high viscosity index, low volatility and good lubricity.

[0006] In a first aspect, the present invention provides an environmentally friendly and biodegradable gear lubricant, which is prepared from the following components in weight percentage: Base oil 50-60%, additives 15-25%, modified castor oil 23-38%, antioxidant 5-10%, tackifier 5-8%; The base oil comprises pentaerythritol ester, butylene adipate, butylene terephthalate and a catalyst, and the mass ratio of the pentaerythritol ester, butylene adipate and butylene terephthalate is 1.2-2.5:3.1-4.5:2-3.

[0007] Preferably, it is prepared from the following components in weight percentage: Base oil 55-60%, additives 18-25%, modified castor oil 31-38%, antioxidant 8-10%, tackifier 5-8%; The base oil comprises pentaerythritol ester, butylene adipate, butylene terephthalate and a catalyst, and the mass ratio of the pentaerythritol ester, butylene adipate and butylene terephthalate is 1.5-2.5:3.5-4.5:2-3.

[0008] Preferably, the catalyst is one or both of ammonium molybdate tetrahydrate and ethyl orthosilicate.

[0009] Preferably, the modified castor oil comprises castor oil and NiMo / Al2O3-SiO2, and the mass ratio of the castor oil to NiMo / Al2O3-SiO2 is 3-5:1-2.

[0010] Preferably, the modified castor oil comprises castor oil and NiMo / Al2O3-SiO2, and the mass ratio of the castor oil to NiMo / Al2O3-SiO2 is 3:1.

[0011] Preferably, the method for preparing modified castor oil comprises the following steps: hydrogenating unsaturated hydrocarbons in castor oil using a NiMo / Al2O3-SiO2 catalyst, and then modifying the castor oil by transesterification using sodium methoxide to obtain modified castor oil.

[0012] Preferably, the additive is one or more of ZrO2, MoS2 and a surfactant.

[0013] Preferably, the surfactant is one or more of alkylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, polyvinyl pyrrolidone, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium oleate, gum arabic, dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, lecithin, and hydroxysulfobetaine.

[0014] Preferably, the tackifier is one or both of polyacrylamide and polyisobutylene.

[0015] Preferably, the antioxidant is one or more of antioxidant 1010, antioxidant 1076, and antioxidant 168.

[0016] In a second aspect, the present invention provides a method for preparing an environmentally friendly and degradable gear lubricant, comprising the following steps: mixing the components uniformly and obtaining the lubricant after grinding.

[0017] In a third aspect, the present invention provides an application of an environmentally friendly and degradable gear lubricant, and the application of the prepared lubricant in various spur gears, helical gears and bevel gear equipment in environmentally sensitive areas.

[0018] In summary, the present invention has the following beneficial effects: 1. In the present invention, castor oil is a high-grade lubricant with more -OH groups than general vegetable oils, which makes castor oil more polar than other vegetable oils. Its metal adsorption and lubrication capabilities are very outstanding, so it is easy to adsorb on the metal friction surface to form a lubricating film. The base oil of the oil-based nano bio-lubricant should first consider environmentally friendly and renewable plant lubricants. The preparation of mixed plant oils with combined characteristics is an idea to improve the physical properties of bio-lubricants; 2. The polar groups in the molecular structure of the vegetable oil of the present invention can form an adsorption film on the metal surface during the lubrication process, which has a good lubrication effect. However, since the vegetable oil is easily oxidized, an antioxidant needs to be added to improve the physical properties of the vegetable oil. The main component of most vegetable oils is fatty acid glycerides. The presence of unsaturated double bonds in the carbon chain of fatty acids leads to poor oxidation stability. Adding antioxidants is undoubtedly the most direct way to improve the oxidation stability of vegetable oils. 2. Although the hydrogenation modification and epoxidation modification of the vegetable oil of the present invention can effectively improve its oxidation stability, they also affect the low-temperature fluidity of the vegetable oil, resulting in a loss of one thing while gaining another. The viscosity of the vegetable oil can be effectively reduced by the ester exchange reaction, thereby improving its low-temperature fluidity. After adding the thickener, the viscosity of the lubricant is enhanced. The selection of antioxidants is very important for vegetable oil lubricants, especially green lubricants. Vegetable oils often contain a high degree of unsaturation, which makes their antioxidant performance poor. Therefore, it is often necessary to add some antioxidants to improve the antioxidant capacity of the lubricant and delay its aging process.

[0019] 4. In the present invention, the modified castor oil is hydrogenated by a catalyst, and then sodium methoxide is used to perform transesterification modification on the castor oil, so that the modified castor oil reacts with pentaerythritol ester, butylene adipate ester, and butylene terephthalate ester in the base oil to generate TMP ester and PE ester respectively. The lubrication ability and viscosity of the TMP ester and PE ester formed by the reaction are significantly improved. Under high load-bearing pressure, the oil film formed by the two esters is still stable and does not break. The transesterification reaction is the replacement of triglycerides in vegetable oil by alcohols, and mainly has two steps: (1) triglycerides and low-carbon alcohols undergo esterification reaction to prepare fatty acid methyl esters; (2) methyl esters and long-chain alcohols continue to undergo esterification under the action of a catalyst to generate another ester; the vegetable oil modified by transesterification not only retains its good low-temperature fluidity and viscosity, but also improves its oxidation stability and load-bearing capacity.

[0020] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to limit the scope of protection of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions are carried out according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources. Example

[0022] Example 1

[0023] An environmentally friendly and biodegradable gear lubricant is prepared from the following components by weight: Base oil 100g, additive 25g, modified castor oil 38g, antioxidant 10g, tackifier 8g; The base oil includes pentaerythritol ester, butylene adipate, butylene terephthalate and a catalyst, wherein the mass ratio of pentaerythritol ester, butylene adipate and butylene terephthalate is 1.2:3.1:2; the catalyst is prepared by a simple and efficient solid phase grinding method using ammonium molybdate tetrahydrate and tetraethyl orthosilicate as molybdenum source and silicon source, and the catalyst is used to synthesize pentaerythritol isooctanoate; The preparation method of modified castor oil comprises the following steps: hydrogenating unsaturated hydrocarbons in castor oil with NiMo / Al2O3-SiO2 catalyst, and then performing transesterification modification on castor oil with sodium methoxide to obtain modified castor oil; The additives are ZrO2, MoS2 and surfactant; the surfactant is alkylphenol polyoxyethylene ether; The thickener is polyacrylamide; the antioxidant is antioxidant 1010; The preparation method of the environmentally friendly and degradable gear lubricant comprises the following steps: mixing the components uniformly and obtaining the lubricant after grinding.

[0024] Example 2

[0025] An environmentally friendly and biodegradable gear lubricant is prepared from the following components by weight: Base oil 120g, additive 28g, modified castor oil 32g, antioxidant 12g, tackifier 8g; The base oil includes pentaerythritol ester, butylene adipate, butylene terephthalate and a catalyst, wherein the mass ratio of pentaerythritol ester, butylene adipate and butylene terephthalate is 1.5:3.5:2; the catalyst is prepared by a simple and efficient solid phase grinding method using ammonium molybdate tetrahydrate and tetraethyl orthosilicate as molybdenum source and silicon source, and the catalyst is used for synthesizing pentaerythritol isooctanoate; The preparation method of modified castor oil comprises the following steps: hydrogenating unsaturated hydrocarbons in castor oil with NiMo / Al2O3-SiO2 catalyst, and then performing transesterification modification on castor oil with sodium methoxide to obtain modified castor oil; The additives are ZrO2, MoS2 and surfactant; the surfactant is alkylphenol polyoxyethylene ether; The thickener is polyacrylamide; the antioxidant is antioxidant 1010; The preparation method of the environmentally friendly and degradable gear lubricant comprises the following steps: mixing the components uniformly and obtaining the lubricant after grinding.

[0026] Example 3

[0027] An environmentally friendly and biodegradable gear lubricant is prepared from the following components by weight: Base oil 150g, additive 40g, modified castor oil 42g, antioxidant 15g, tackifier 8g; The base oil includes pentaerythritol ester, butylene adipate, butylene terephthalate and a catalyst, wherein the mass ratio of pentaerythritol ester, butylene adipate and butylene terephthalate is 1.8:4.2:2.2; the catalyst is prepared by a simple and efficient solid phase grinding method using ammonium molybdate tetrahydrate and tetraethyl orthosilicate as molybdenum source and silicon source, and the catalyst is used to synthesize pentaerythritol isooctanoate; The preparation method of modified castor oil comprises the following steps: hydrogenating unsaturated hydrocarbons in castor oil with NiMo / Al2O3-SiO2 catalyst, and then performing transesterification modification on castor oil with sodium methoxide to obtain modified castor oil; The additives are ZrO2, MoS2 and surfactant; the surfactant is dodecyltrimethylammonium bromide; The thickener is polyacrylamide; the antioxidant is antioxidant 1076; The preparation method of the environmentally friendly and degradable gear lubricant comprises the following steps: mixing the components uniformly and obtaining the lubricant after grinding.

[0028] Example 4

[0029] An environmentally friendly and biodegradable gear lubricant is prepared from the following components by weight: Base oil 165g, additive 35g, modified castor oil 55g, antioxidant 12g, tackifier 8g; The base oil includes pentaerythritol ester, butylene adipate, butylene terephthalate and a catalyst, wherein the mass ratio of pentaerythritol ester, butylene adipate and butylene terephthalate is 1.5:4.2:2.2; the catalyst is prepared by a simple and efficient solid phase grinding method using ammonium molybdate tetrahydrate and tetraethyl orthosilicate as molybdenum source and silicon source, and is used to synthesize pentaerythritol isooctanoate; The preparation method of modified castor oil comprises the following steps: hydrogenating unsaturated hydrocarbons in castor oil with NiMo / Al2O3-SiO2 catalyst, and then performing transesterification modification on castor oil with sodium methoxide to obtain modified castor oil; The additives are ZrO2, MoS2 and surfactant; the surfactant is hydroxysulfobetaine; The thickener is polyacrylamide; the antioxidant is antioxidant 168; The preparation method of the environmentally friendly and degradable gear lubricant comprises the following steps: mixing the components uniformly and obtaining the lubricant after grinding.

[0030] Comparative Example Comparative Example 1 The difference between this comparative example and Example 3 is that no modified castor oil is added, and the remaining steps and raw materials are the same as those of Example 3.

[0031] Comparative Example 2 The difference between this comparative example and Example 3 is that no catalyst is added to the base oil, and the remaining steps and raw materials are the same as those of Example 3.

[0032] Comparative Example 3 The difference between this comparative example and Example 3 is that castor oil is not modified, and the remaining steps and raw materials are the same as those in Example 3.

[0033] The environmentally friendly and degradable gear lubricants prepared in Examples 1-4 and Comparative Examples 1-3 were tested for minimum operating temperature, anti-wear performance, Vicat softening temperature, biodegradation rate and flame retardancy, wherein the minimum operating temperature (°C) was measured according to the SH / T0048 method, the test shear rate was 10s-1, and at a certain temperature, when the test result (similar viscosity) of the lubricant was 1500±50Pa•s, this temperature was the minimum operating temperature that the lubricant could meet for use; anti-wear performance (mm): measured according to GB / T3142, the test conditions were: room temperature, 392N, 1200r / min, 60min; the Vicat softening temperature was measured according to the GB / T 1633-2000 standard; the biodegradation rate was measured according to the GB / T 19277-2011 standard was used to measure the final release of carbon dioxide after 60 days of degradation of the environmentally friendly degradable gear lubricants prepared in Examples 1-4 and Comparative Examples 1-3. The biodegradability rate (%) of the material was expressed by the ratio of the actual carbon dioxide release to its theoretical maximum release; the flame retardancy was measured using the UL 94 standard. The test results are shown in Table 1: Table 1 Performance parameters of environmentally friendly degradable gear lubricants prepared in Examples 1-4 and Comparative Examples 1-3 project Minimum operating temperature / ℃ Wear resistance / mm Vicat softening temperature / ℃ Biodegradation rate / % Flame retardant Example 1 -35 0.42 97.5 99 ⅴ-0 Example 2 -35 0.41 98.5 98 ⅴ-0 Example 3 -45 0.45 99.5 100 ⅴ-0 Example 4 -38 0.43 98.0 97 ⅴ-0 Comparative Example 1 -25 0.32 95.2 85 ⅴ-1 Comparative Example 2 -30 0.35 96.3 91 ⅴ-1 Comparative Example 3 -32 0.37 96.6 88 ⅴ-2 As can be seen from Table 1 above, compared with Comparative Examples 1-3, the environmentally friendly and degradable gear lubricants prepared in Examples 1-4 are hydrogenated by modified castor oil using a catalyst, and then the castor oil is transesterified using sodium methoxide, so that the modified castor oil reacts with pentaerythritol ester, butylene adipate, and butylene terephthalate in the base oil to generate TMP ester and PE ester, respectively. The vegetable oil modified by transesterification not only retains its good low-temperature fluidity and viscosity, but also improves its oxidation stability and load capacity. The selection of antioxidants has great significance for vegetable oil lubricants, especially green lubricants. The antioxidant is very important. Most vegetable oils contain a high degree of unsaturation, which makes their antioxidant performance poor. Therefore, it is often necessary to add some antioxidants to improve the antioxidant capacity of the lubricant and delay its aging process. The environmentally friendly and degradable gear lubricants prepared in Comparative Examples 1-3 did not meet the performance requirements, indicating that the polar groups in the molecular structure of the vegetable oil in the environmentally friendly and degradable gear lubricant prepared by the present invention can form an adsorption film on the metal surface during the lubrication process, and have a good lubrication effect. However, due to the easy oxidation characteristics of vegetable oil, antioxidants need to be added to improve the physical properties of vegetable oil. The main component of most vegetable oils is fatty acid glyceride. The presence of unsaturated double bonds in the carbon chain of fatty acids leads to poor oxidation stability. Adding antioxidants is undoubtedly the most direct way to improve the oxidation stability of vegetable oils.

[0034] The above is only an exemplary embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An environmentally friendly and degradable gear lubricant, characterized in that: It is prepared from the following components in weight percentage: Base oil 50-60%, additives 15-25%, modified castor oil 23-38%, antioxidant 5-10%, tackifier 5-8%; The base oil comprises pentaerythritol ester, butylene adipate, butylene terephthalate and a catalyst, and the mass ratio of the pentaerythritol ester, butylene adipate and butylene terephthalate is 1.2-2.5:3.1-4.5:2-3.

2. The environmentally friendly and degradable gear lubricant according to claim 1, characterized in that: The catalyst is one or both of ammonium molybdate tetrahydrate and ethyl orthosilicate.

3. The environmentally friendly and degradable gear lubricant according to claim 1, characterized in that: Modified castor oil includes castor oil and NiMo / A l2 O3-SiO 2， The mass ratio of the castor oil to NiMo / Al2O3-SiO2 is 3-5:1-2.

4. The environmentally friendly and degradable gear lubricant according to claim 1, characterized in that: Preparation method of modified castor oil, The method comprises the following steps: using a NiMo / Al2O3-SiO2 catalyst to hydrogenate unsaturated hydrocarbons in castor oil, and then using sodium methoxide to perform ester exchange modification on the castor oil to obtain modified castor oil.

5. The environmentally friendly and degradable gear lubricant according to claim 1, characterized in that: The additive is one or more of ZrO2, MoS2 and a surfactant.

6. The environmentally friendly and degradable gear lubricant according to claim 5, characterized in that: The surfactant is one or more of alkylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, polyvinyl pyrrolidone, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium oleate, gum arabic, dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, lecithin, and hydroxysulfobetaine.

7. The environmentally friendly and degradable gear lubricant according to claim 1, characterized in that: The tackifier is one or both of polyacrylamide and polyisobutylene.

8. The environmentally friendly and degradable gear lubricant according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 1010, antioxidant 1076, and antioxidant 168.

9. The method for preparing the environmentally friendly and degradable gear lubricant according to any one of claims 1 to 8, characterized in that: The following steps are involved: The components are mixed evenly and grinded to obtain a lubricant.

10. Use of the lubricant according to any one of claims 1 to 8 or the lubricant prepared by the method according to claim 9 in various spur gears, helical gears and bevel gears in environmentally sensitive areas.