A sulfuramide-containing organic molybdenum compound and its preparation method and application

Abstract

The present invention discloses a sulfur-containing amide type organic molybdenum compound and its preparation method and application, which belongs to the technical field of lubricating additives. The structural formula is as follows: #imgabs0# wherein R1 is a C2-C3 straight chain or branched alkyl group, R2 is a C8-C 26 Straight-chain or branched alkyl; a sulfur-amide-type organic molybdenum compound prepared by the present invention can be used as a lubricating grease additive, has good tribological properties, and can significantly improve the friction-reducing and anti-wear properties of lubricating grease.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating additives and relates to a sulfuramide-containing organic molybdenum compound and a preparation method and application thereof. Background Art

[0002] Friction and wear are among the main factors that lead to energy loss, reduced energy utilization, increased material loss, or even damage. During the operation of mechanical equipment, adding appropriate friction reducers can reduce friction and wear on the friction pair, thereby improving energy utilization and equipment life.

[0003] Molybdenum compounds have a long history as friction modifiers. Molybdenum disulfide was the earliest molybdenum compound used, but its insolubility in lubricating oils significantly limited its application. Subsequently, oil-soluble organic molybdenum compounds, represented by molybdenum dialkyl dithiophosphates (Mo DDP), were developed and primarily used in the field of internal combustion engines. However, while the presence of phosphorus effectively reduces metal friction, it can poison the three-way catalyst in automobile exhaust treatment systems. Therefore, the development of environmentally friendly organic molybdenum friction reducers has become a major research focus.

[0004] Chinese patent CN1 01029265A uses p-hydroxyphenyl alkyl acid polyol ester, inorganic molybdenum compound, and fatty amine, aromatic amine, mixed amine, amide or a mixture of any two or more thereof to react to obtain a sulfur- and phosphorus-free organic molybdenum lubricating additive.

[0005] US Patent No. 6,645,921 B2 uses oil, diamine and molybdenum compound to react in the absence of a volatile organic solvent to form a product with a high molybdenum content, and the reaction product can be used to remove unreacted molybdenum compound without filtering.

[0006] In summary, the currently disclosed nitrogen-containing organic molybdenum additives meet the need for green and environmentally friendly lubricant additives, but their friction-reducing effect needs to be further improved. Therefore, the invention of a green and environmentally friendly, highly effective friction-reducing lubricant additive would have a positive impact on the field of lubricant grease technology. Summary of the Invention

[0007] In view of the defects in the prior art, the first aspect of the present invention is to provide a sulfuramide-containing organic molybdenum compound.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] The present invention provides a sulfuramide-containing organic molybdenum compound having the following structure:

[0010]

[0011] Wherein R1 is a C2-C3 straight chain or branched alkyl group, R2 is a C8-C 26 Straight-chain or branched-chain alkyl.

[0012] The second aspect of the present invention is to provide a method for preparing a sulfuramide-containing organic molybdenum compound, comprising the following steps:

[0013] (1) reacting a mercaptocarboxylic acid, an organic solvent, and an amine compound at 60 to 150° C. for 1 to 10 hours to obtain a sulfuramide-containing organic ligand;

[0014] (2) reacting the sulfuramide-containing organic ligand and the molybdenum compound at 100-180° C. for 6-20 hours to obtain a sulfuramide-containing organic molybdenum compound.

[0015] The preparation method involves the following chemical equation:

[0016]

[0017] As a preferred option:

[0018] In step (1):

[0019] The amine compound is selected from aliphatic amine, aromatic amine or a mixed amine thereof.

[0020] The solvent is selected from any one of ethanol, methanol, propanol, tetrahydrofuran, dioxane, ethylene glycol, glycerol, acetone, N,N-dimethylformamide, benzene, toluene, xylene, petroleum ether, kerosene, etc., preferably petroleum ether or toluene.

[0021] The reaction temperature is preferably 80° C., and the reaction time is 4 hours.

[0022] In step (2):

[0023] The molybdenum compound is selected from an organic or inorganic molybdenum source, and is preferably any one of molybdenum trioxide, molybdenum acetylacetonate, ammonium molybdate, sodium molybdate, and the like.

[0024] The molar ratio of the oil-soluble organic carboxylate to the molybdenum source compound is 1:0.25-1, preferably 1:1.

[0025] The reaction temperature is preferably 130° C., and the reaction time is 10 hours.

[0026] A third aspect of the present invention is to provide a use of a sulfuramide-containing organic molybdenum compound as a lubricating grease additive.

[0027] As a preferred embodiment, the amount of the sulfuramide-type organic molybdenum compound added to the lubricating grease is 1 to 10 wt.%, preferably 1 to 4 wt.%, based on the weight of the lubricating grease.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The present invention uses mercaptocarboxylic acid and aliphatic amine, aromatic amine, and mixed amine to react, which has a simple process, is easy to operate, and is environmentally friendly.

[0030] (2) The product has good tribological properties and can significantly improve the anti-friction and anti-wear properties as a lubricating grease additive. The present invention is further described below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0032] Figure 1 Schematic diagram of infrared spectrum analysis of the friction reducer 4n-MoTMP prepared in Example 1;

[0033] Figure 2 The friction reducing properties of the friction reducer 4n-MoTMP prepared in Example 1 with different addition amounts to urea-based grease are shown;

[0034] Figure 3 The anti-wear properties of the friction reducer 4n-MoTMP prepared in Example 1 with different addition amounts in urea-based grease are shown;

[0035] Figure 4 The friction reducing properties of the friction reducer 4n-MoTMP prepared in Example 1 are different when loaded in urea-based grease;

[0036] Figure 5 The anti-wear properties of the friction reducer 4nMoTMP prepared in Example 1 loaded with different amounts of urea-based grease are shown. DETAILED DESCRIPTION

[0037] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0038] Example 1

[0039] 2.12 g of mercaptopropionic acid and 50 ml of petroleum ether solution were added to a 100 ml three-necked flask, 5.35 g of oleylamine (the molar ratio of mercaptopropionic acid and oleylamine was 1:1) was added, and the mixture was heated at 80 ° C. with stirring and reflux for 4 h. 0.72 g of molybdenum trioxide (the molar ratio of mercaptopropionic acid and molybdenum trioxide was 4:1) was continued to be added, and the mixture was heated at 130 ° C. with stirring and reflux for 10 h. There was no solid powder in the reaction solution, and the reaction was terminated. After cooling to room temperature, the petroleum ether solvent was removed by distillation under reduced pressure to obtain 6.51 g of a dark yellow paste liquid, which was a sulfuramide-type organic molybdenum compound, marked as 4n-MoTMP, with a yield of 84.04%.

[0040] The above reaction equation:

[0041]

[0042] Product Confirmation:

[0043] FT-IR spectrum of the product (see Figure 1 )as follows:

[0044] 3312cm-1, NH stretching vibration absorption peak; 2921cm -1 , CH stretching vibration absorption peak; 1652cm-1, C=O stretching vibration absorption peak; 1458cm -1 , CN stretching vibration absorption peak; 714cm -1 , Mo-SC stretching vibration absorption peak.

[0045] Table 1. ICP test results of molybdenum and sulfur contents of the product of Example 1

[0046] element Mo S Measured value (%) 6.20 6.02 .

[0047] Replacement Example

[0048] The preparation method is the same as that of Example 1, except that the reaction temperature of the sulfuramide-containing organic ligand and the molybdenum compound is adjusted, and its effect on the yield of the product of Example 1 is tested.

[0049] Table 2. Effect of reaction temperature on product yield of Example 1

[0050] Serial number Reaction temperature (℃) Yield (%) Example 1-1 100 60.41 Example 1-2 110 68.56 Examples 1-3 120 79.13 Examples 1-4 140 82.97 Examples 1-3 150 82.56 .

[0051] As shown in Table 2, at lower temperatures, the reactants are less active, making it difficult for water molecules to escape from the system, resulting in lower yields of the target product. Increasing the reaction temperature promotes the forward progress of the amidation reaction, increasing the conversion rate of the reactants. However, at higher temperatures, the yield of the product in Example 1 does not change significantly, so the optimal temperature is 130°C.

[0052] Example 2

[0053] 1.06 g of mercaptopropionic acid and 40 ml of petroleum ether solution were added to a 100 ml three-necked flask, 2.68 g of oleylamine (the molar ratio of mercaptopropionic acid and oleylamine was 1:1) was added, and the mixture was heated under reflux with stirring at 80° C. for 4 h. 0.72 g of molybdenum trioxide (the molar ratio of mercaptopropionic acid and molybdenum trioxide was 2:1) was continued to be added, and the mixture was heated under reflux with stirring at 130° C. for 10 h. When there was no solid powder in the reaction solution, the reaction was terminated. After cooling to room temperature, the petroleum ether solvent was removed by distillation under reduced pressure to obtain 3.65 g of a dark yellow paste liquid, which was a sulfuramide-type organic molybdenum compound, marked as 2n-MoTMP, with a yield of 85.68%.

[0054] The above reaction equation:

[0055]

[0056] Table 3. ICP test results of molybdenum and sulfur contents of the product of Example 2

[0057] element Mo S Measured value (%) 11.25 5.56 .

[0058] Application Example: Application of Sulfamide-Containing Organic Molybdenum Compounds as Friction Reducers

[0059] In accordance with NB / SH / T 0189-2017 and GB / T 3142-2019 standards, the sulfuramide-containing organic molybdenum compound prepared in Example 1 was added to the base grease (urea-based grease) at different contents (the added amounts were the mass percentages of urea-based grease: 1%, 2%, 3%, and 4%). After stirring evenly, the average coefficient of friction (ACOF) and wear spot diameter (WSD) were measured.

[0060] The test method is as follows: Using an MS-10J four-ball testing machine from Xiamen Tianji Automation Co., Ltd., the steel balls used were Grade 2 GCr15 standard steel balls (AISI-52100), with a diameter of 12.7 mm and a hardness of 59-61 HRC. The test was conducted under a load of 392 N, a temperature of 75°C, a test time of 60 minutes, and a rotation speed of 1200 rpm. The test results are shown in Table 4:

[0061] Table 4. Tribological properties of Example 1 at different addition amounts in urea-based grease

[0062] Concentration of Example 1 (%) Average friction coefficient Wear spot diameter (mm) 0.0 0.0980 0.673 1.0 0.0786 0.505 2.0 0.0621 0.425 3.0 0.0787 0.413 4.0 0.0620 0.428 .

[0063] An MS-10J four-ball testing machine from Xiamen Tianji Automation Co., Ltd. was used, using Grade 2 GCr15 standard steel balls (AISI-52100). A sulfuramide-containing organic molybdenum compound prepared in Example 1 was added to a base grease (urea-based grease) at a concentration of 2% by weight. Tests were conducted at various loads at a temperature of 75°C, a test time of 60 minutes, and a rotational speed of 1200 rpm. The test results are shown in Table 5.

[0064] Table 5. Tribological properties of Example 1 with 2% addition under different loads

[0065] Load (N) Average friction coefficient Wear spot diameter (mm) 196 0.0992 0.392 294 0.0805 0.386 392 0.0621 0.425 490 0.0816 0.568 .

[0066] The results show that the sulfuramide-type organic molybdenum compound synthesized in the embodiment of the present invention can effectively reduce the coefficient of friction (COF) and the wear spot diameter (WSD). The technical solution of the present invention has the following advantages: green and environmentally friendly process, simple and efficient separation, excellent friction reduction and anti-wear performance, and broad application prospects.

[0067] The present invention has many specific application paths, and the above is only a preferred embodiment of the present invention. It should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention. For those skilled in the art, several improvements can be made without departing from the principles of the present invention, and these improvements should also be considered as the scope of protection of the present invention.

Claims

1. A sulfuramide-type organic molybdenum compound having the following structural formula: ， Wherein: R1 is a C2~C3 straight chain or branched alkyl group, R2 is a C8~C 26 A straight chain or branched chain alkyl group.

2. A method for preparing the sulfuramide-containing organic molybdenum compound according to claim 1, characterized in that: The following steps are involved: (1) reacting mercaptocarboxylic acid, an organic solvent, and an amine compound at 60 to 150° C. for 1 to 10 hours to obtain a sulfuramide-containing organic ligand; (2) reacting the sulfuramide-containing organic ligand and the molybdenum compound at 100-180° C. for 6-20 hours to obtain a sulfuramide-containing organic molybdenum compound; The preparation method involves the following chemical equation: ， Wherein: R1 is a C2~C3 straight chain or branched alkyl group, R2 is a C8~C 26 A straight chain or branched chain alkyl group.

3. The method for preparing a sulfuramide-containing organic molybdenum compound according to claim 2, wherein: In step (1), the organic solvent is selected from any one of ethanol, methanol, propanol, tetrahydrofuran, dioxane, ethylene glycol, glycerol, acetone, N,N-dimethylformamide, benzene, toluene, xylene, and petroleum ether.

4. The method for preparing a sulfuramide-containing organic molybdenum compound according to claim 2, wherein: In step (1): the reaction temperature is 80°C and the reaction time is 4 hours.

5. The method for preparing a sulfuramide-containing organic molybdenum compound according to claim 2, wherein: In step (2): the molybdenum compound is selected from any one of molybdenum trioxide, ammonium molybdate, and sodium molybdate.

6. The method for preparing a sulfuramide-containing organic molybdenum compound according to claim 2, wherein: In step (2): the molar ratio of the sulfur amide organic ligand to the molybdenum compound is 1:0.25-1.

7. The method for preparing a sulfuramide-containing organic molybdenum compound according to claim 2, wherein: In step (2): the reaction temperature is 130°C and the reaction time is 10 hours.

8. Use of the sulfuramide-containing organic molybdenum compound according to claim 1 as a lubricating grease additive.

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