阅读说明：本技术 一种重载轴承润滑脂组合物及其制备方法 (Heavy-duty bearing lubricating grease composition and preparation method thereof ) 是由 王兆坤 李英姿 刘青山 张晓凯 刘亚春 于 2020-07-23 设计创作，主要内容包括：本发明涉及一种重载轴承润滑脂组合物及其制备方法。以组合物总重量为基准,该组合物包含以下组分：脂肪酸3.0～9.0％；二元酸1.5～3.5％；氢氧化锂1.2～2.3％；结构改进剂10.0～30.0％；抗氧剂1.0～4.0％；防锈剂1.0～4.0％；极压抗磨剂1.5～6.0％；固体剂1.5～6.0％；基础油余量；所述基础油为矿物油、聚α烯烃合成油和GTL的混合物；所述结构改进剂选自苯乙烯-丁二烯、苯乙烯-异戊二烯、丙烯丁烯共聚物和小粘度基础油中的一种或多种。本发明提供的重载润滑脂组合物克服了润滑脂在使用中启动转矩大、使用寿命不足的缺陷,在各项性能稳定的前提下,具有优良的低温性能和承载能力。(The invention relates to a heavy-duty bearing lubricating grease composition and a preparation method thereof. The composition comprises the following components by taking the total weight of the composition as a reference: 3.0-9.0% of fatty acid; 1.5-3.5% of dibasic acid; 1.2-2.3% of lithium hydroxide; 10.0-30.0% of a structure improver; 1.0-4.0% of an antioxidant; 1.0-4.0% of an antirust agent; 1.5-6.0% of an extreme pressure antiwear agent; 1.5-6.0% of a solid agent; the balance of base oil; the base oil is a mixture of mineral oil, polyalphaolefin synthetic oil and GTL; the structure improver is selected from one or more of styrene-butadiene, styrene-isoprene, propylene butylene copolymer and low-viscosity base oil. The heavy-duty lubricating grease composition provided by the invention overcomes the defects of large starting torque and short service life of lubricating grease in use, and has excellent low-temperature performance and bearing capacity on the premise of stable performance.)

1. The heavy-duty bearing grease composition is characterized by comprising the following components by weight:

the base oil is a mixture of mineral oil, polyalphaolefin synthetic oil and GTL;

the structure improver is selected from one or more of styrene-butadiene, styrene-isoprene, propylene butylene copolymer and low-viscosity base oil.

2. The grease composition for heavy-duty bearings according to claim 1, wherein the mass ratio of the mineral oil, the polyalphaolefin synthetic oil and the GTL in the base oil is (7-4): 1-3): 3-1, preferably (7-5): 2-3): 2-1; the kinematic viscosity of the base oil at 40 ℃ is 200-400 mm²(ii)/s, pour point not higher than-20 ℃.

3. The grease composition for heavy-duty bearings according to claim 1 or 2, wherein the fatty acid is a mixture of dodecahydroxystearic acid and hydrogenated castor oil, preferably, the mass ratio of the dodecahydroxystearic acid to the hydrogenated castor oil is (8.5-9.5): (1.5-0.5).

4. A heavy duty bearing grease composition according to any one of claims 1 to 3, said dibasic acid being a mixture of azelaic acid, adipic acid and dodecanedioic acid, preferably the mass ratio of said azelaic acid, said adipic acid and said dodecanedioic acid is (7.0-8.0): (1.5-1.0).

5. The heavy duty bearing grease composition according to any one of claims 1 to 4 wherein the texturing agent comprises texturing agent 1 and texturing agent 2; the structure improver 1 is selected from one or more of styrene-butadiene, styrene-isoprene and propylene-butylene copolymers; the structure improver 2 is low-viscosity base oil, and the kinematic viscosity at 40 ℃ is 5-20 mm²/s。

6. The grease composition for heavy-duty bearings according to claim 5, wherein the composition contains 5.0 to 15.0% by weight of the structure-improving agent 1 and 5.0 to 15.0% by weight of the structure-improving agent 2.

7. The heavy-duty bearing grease composition according to any one of claims 1 to 6, wherein the antioxidant is a mixture of an amine compound and a phenol compound, and the mass ratio of the amine compound to the phenol compound is (1-2): 2-1, preferably 1: 1; preferably, the amine compound is aniline or naphthylamine, and the phenol compound is alkyl monophenol, bisphenol or high molecular polyphenol;

and/or the antirust agent is a mixture of dicarboxylic acids, acylamino acids and sulfonate, and the mass ratio of the dicarboxylic acids, the acylamino acids and the sulfonate is (1-2): 2-4, preferably 1:2: 2; preferably, the dicarboxylic acids include alkenyl succinic acid, imidazolinyl succinic acid salt or other long-chain alkyl dicarboxylic acids, the acyl amino acids are N-oleoyl sarcosine octadecylamine salt or other acyl amino acid salts, and the sulfonate includes barium sulfonate or zinc sulfonate;

and/or the extreme pressure antiwear agent is a mixture of sulfurized olefin, phosphate and antimony phosphate, the mass ratio of the sulfurized olefin to the phosphate to the antimony phosphate is (1-3) to (2-1) to (1-3), and the preferred mass ratio is 2:1: 2; preferably, the sulfurized olefin comprises sulfurized isobutylene or sulfurized tributylene, and the phosphate ester comprises tricresyl phosphate or triethyl phosphate;

and/or the solid agent is a mixture of zinc sulfide, expanded graphite, hydrotalcite and molybdenum disulfide, and the mass ratio of the zinc sulfide, the expanded graphite, the hydrotalcite and the molybdenum disulfide is (1-2): 1-2, preferably 1:2:2: 2.

8. The heavy duty bearing grease composition according to claim 1, comprising the following components, based on the total weight of the composition:

9. the method for preparing a grease composition for heavy-duty bearings according to any one of claims 1 to 8, wherein 30 to 60% of base oil, fatty acid, dibasic acid, lithium hydroxide and a structure-improving agent 1 are mixed, and the mixture is heated and pressurized, and is kept under a constant pressure for 40 to 60min when the pressure reaches 0.50 to 0.70 MPa; then the pressure is released to zero; and continuously heating to 190-220 ℃, keeping the temperature for 5-10min, adding 10-30% of base oil for cooling, adding an antioxidant and a structure improver 2 when the temperature is reduced to 160-185 ℃, simultaneously adding the rest of base oil, adding a solid agent, an antirust agent and an extreme pressure antiwear agent when the temperature is reduced to 80-120 ℃, stirring for 30-60 min, and carrying out aftertreatment to obtain the lubricant.

10. The preparation method of claim 9, wherein 40-50% of base oil, fatty acid, dibasic acid, lithium hydroxide and the structure improver 1 are mixed, the temperature and the pressure are raised, when the pressure reaches 0.50-0.70 MPa, the pressure is kept constant for 40-50 min, then the pressure is relieved to zero, the temperature is continuously raised to 200-210 ℃, the temperature is kept constant for 5-10min, 10-20% of base oil is added for cooling, when the temperature is lowered to 170-185 ℃, the antioxidant and the structure improver 2 are added, meanwhile, the rest of the base oil is added for thickening, when the temperature is lowered to 90-110 ℃, the solid agent, the antirust agent and the extreme pressure antiwear agent are sequentially added, the mixture is stirred for 50-60 min, and the mixture is subjected to post-treatment to obtain the catalyst.

Technical Field

The invention relates to the technical field of lubricating grease, and particularly relates to a heavy-duty bearing lubricating grease composition and a preparation method thereof.

Background

With the development of modern engineering construction and modern industry, large-scale mechanical equipment and construction equipment are emerging continuously, and develop towards the direction of heavy load, and the application range of heavy-duty bearing is wider and wider. The heavy-duty bearing is mostly arranged at a key part of large-scale equipment, the using effect of the heavy-duty bearing is directly related to the service life and the economic life of the equipment, and if the bearing breaks down, the equipment has long maintenance period and high cost, not only can influence normal production operation, but also can bring huge economic loss. Analysis of the cause of bearing failure indicates that about 40% of bearing failure is associated with poor lubrication. For most equipment, the primary means of addressing friction and wear is to enhance lubrication. Therefore, the lubrication of the heavy-duty bearing is important, and the running quality of equipment is directly influenced if the selection of a lubricating material is reasonable. The grease used for the bearing is calcium-based grease, sodium-based grease, calcium-sodium-based grease, lithium-based grease, aluminum-based grease, molybdenum disulfide grease, etc. For heavy duty bearings, soap-based greases based on high viscosity base oils with solid fillers added are generally preferred.

With the continuous expansion of the application field of the lubricating grease, the heavy-load extreme pressure type lubricating grease in the prior art cannot meet the lubricating requirements of heavy-load friction parts such as engineering machinery, heavy-load automobiles, mining equipment, oil field machinery, conveying equipment and the like in a field low-temperature environment due to poor low-temperature performance and insufficient bearing capacity. Therefore, on the premise of ensuring the stability of various properties of the grease, how to further improve the low-temperature performance and the bearing capacity of the grease becomes a technical problem to be solved urgently by those skilled in the art. The prior art has higher requirements on production equipment in actual industrial production and is not beneficial to large-scale production, for example, the original material in patent CN107502405A contains ethanol, and is flammable and explosive; part of the technology is special products, which do not have a universal type, and the patent CN103450978A is specially used for heavy-duty automobile hub bearings; some technologies only pay attention to and improve individual properties of the lubricating grease, for example, patent CN109294713A highlights low temperature, and high-speed heavy load is highlighted in "development of high-speed heavy-load rolling bearing lubricating grease" in 2018, 2 nd, however, the above technologies still have problems of small oil distribution, large starting torque and the like, and comprehensive properties such as starting performance, service life and the like of the lubricating grease need to be improved.

Disclosure of Invention

In order to solve the technical problems, embodiments of the present invention provide a grease composition for heavy duty bearings and a preparation method thereof. The heavy-duty lubricating grease composition provided by the invention overcomes the defects of large starting torque and short service life of lubricating grease in use, and has excellent low-temperature performance and bearing capacity on the premise of stable performance.

The invention provides a heavy-duty bearing lubricating grease composition, which comprises the following components by taking the total weight of the composition as a reference:

the base oil is a mixture of mineral oil, polyalphaolefin synthetic oil and GTL;

the structure improver is selected from one or more of styrene-butadiene, styrene-isoprene, propylene butylene copolymer and low-viscosity base oil.

According to some preferred embodiments of the present invention, the mass ratio of the mineral oil, the polyalphaolefin synthetic oil and the GTL in the base oil is (7-4): 1-3): 3-1, preferably (7-5): 2-3): 2-1; the kinematic viscosity of the base oil at 40 ℃ is 200-400 mm²(ii)/s, pour point not higher than-20 ℃. The three-component base oil adopted by the invention is compounded, so that the low-temperature resistance is good, and meanwhile, the optimized base oil effectively solves the problem of large starting torque through the interaction of the structure improver, andimprove the adhesion, the water resistance and the bearing capacity.

According to some preferred embodiments of the present invention, the fatty acid is a mixture of dodecahydroxystearic acid and hydrogenated castor oil, and preferably, the mass ratio of the dodecahydroxystearic acid to the hydrogenated castor oil is (8.5-9.5): (1.5-0.5).

According to some preferred embodiments of the present invention, the dibasic acid is a mixture of azelaic acid, adipic acid and dodecanedioic acid, and preferably, the mass ratio of azelaic acid, adipic acid and dodecanedioic acid is (7.0-8.0): (1.5-1.0). The thickening agent in the formula is compounded by fatty acid and mixed dibasic acid, and has more excellent high temperature resistance and colloid stability.

According to some preferred embodiments of the invention, the texturing agent comprises a texturing agent 1 and a texturing agent 2; the structure improver 1 is selected from one or more of styrene-butadiene, styrene-isoprene and propylene-butylene copolymers; the structure improver 2 is low-viscosity base oil, and the kinematic viscosity at 40 ℃ is 5-20 mm²/s。

According to some preferred embodiments of the present invention, the composition comprises 5.0 to 15.0% of the structure-improving agent 1 and 5.0 to 15.0% of the structure-improving agent 2. In the invention, the preferable structure improver 1 and the preferable structure improver 2 are compounded with the specific base oil to further improve the oil distribution performance and improve the problem of large starting torque, and simultaneously, the formula plays a synergistic effect to further improve the comprehensive performance of the composition.

According to some preferred embodiments of the present invention, the antioxidant is a mixture of an amine compound and a phenol compound, and the mass ratio of the amine compound to the phenol compound is (1-2): 2-1, preferably 1: 1; preferably, the amine compound is aniline or naphthylamine, and the phenol compound is alkyl monophenol, bisphenol or high molecular polyphenol.

According to some preferred embodiments of the invention, the antirust agent is a mixture of dicarboxylic acids, acylamino acids and sulfonate, and the mass ratio of the dicarboxylic acids, the acylamino acids and the sulfonate is (1-2): 2-4, preferably 1:2: 2; the dicarboxylic acids comprise alkenyl succinic acid, imidazoline succinate or other long-chain alkyl dicarboxylic acids, the acyl amino acids are N-oleoyl sarcosine octadecylamine salt or other acyl amino acid salts, and the sulfonate comprises barium sulfonate or zinc sulfonate.

According to some preferred embodiments of the invention, the extreme pressure anti-wear agent is a mixture of sulfurized olefin, phosphate and antimony phosphate, and the mass ratio of the sulfurized olefin, the phosphate and the antimony phosphate is (1-3): 2-1): 1-3, preferably 2:1: 2; preferably, the sulfurized olefin comprises sulfurized isobutylene or sulfurized tributylene, and the phosphate ester comprises tricresyl phosphate or triethyl phosphate;

according to some preferred embodiments of the present invention, the solid agent is a mixture of zinc sulfide, expanded graphite, hydrotalcite and molybdenum disulfide, and the mass ratio of the zinc sulfide, the expanded graphite, the hydrotalcite and the molybdenum disulfide is (1-2): 1-2 (1-2), preferably 1:2:2: 2. In the invention, the extreme pressure property, the abrasion resistance and the service life of the product are effectively improved by adopting the preferable additive formula, and various comprehensive properties of the formula system are further improved.

According to some preferred embodiments of the present invention, the composition comprises the following components, based on the total weight of the composition:

the invention also provides a preparation method of the heavy-duty bearing lubricating grease composition, which comprises the steps of mixing 30-60% of base oil, fatty acid, dibasic acid, lithium hydroxide and a structure improver 1, raising the temperature and the pressure, and keeping the pressure constant for 40-60 min when the pressure reaches 0.50-0.70 MPa; then the pressure is released to zero (namely normal pressure); and continuously heating to 190-220 ℃, keeping the temperature for 5-10min, adding 10-30% of base oil for cooling, adding an antioxidant and a structure improver 2 when the temperature is reduced to 160-185 ℃, simultaneously adding the rest of base oil, adding a solid agent, an antirust agent and an extreme pressure antiwear agent when the temperature is reduced to 80-120 ℃, stirring for 30-60 min, and carrying out aftertreatment to obtain the lubricant.

According to some preferred embodiments of the invention, 40-50% of base oil, fatty acid, dibasic acid, lithium hydroxide and a structure improver 1 are mixed, the temperature and the pressure are raised, when the pressure reaches 0.50-0.70 MPa, the pressure is constant for 40-50 min, then the pressure is released to zero, the temperature is continuously raised to 200-210 ℃, the temperature is kept for 5-10min, 10-20% of base oil is added for cooling, when the temperature is lowered to 170-185 ℃, an antioxidant and a structure improver 2 are added, meanwhile, the rest of base oil is added for thickening, when the temperature is lowered to 90-110 ℃, a solid agent, an antirust agent and an extreme pressure antiwear agent are sequentially added, the mixture is stirred for 50-60 min, and the mixture is subjected to post-treatment to obtain the composite. In the invention, the rapid production process of the pressure kettle is optimized through the process, the production efficiency is high, and the product consistency is good.

The heavy-duty bearing grease provided by the invention at least has the following advantages:

1) the lubricating grease has excellent starting performance, and is tested by adopting an NB/SH/T0839 standard method, and the starting torque is less than or equal to 7.0 N.m at the temperature of minus 30 ℃.

2) The lubricating grease has good colloid stability, and the oil content is 0.5-3.0% (m/m) at 100 ℃ for 30h by adopting an NB/SH/T0324 method.

3) The lubricating grease prepared by the invention has good seawater-resistant antirust performance, and all bearings are rust-free by adopting NB/SH/T0823 test.

4) The lubricating grease has excellent extreme pressure antiwear performance, and the extreme pressure performance (four-ball method) P is tested by adopting SH/T0202_DThe value is more than or equal to 6080N.

5) The lubricating grease prepared by the invention has excellent water resistance, and the water spray loss is less than or equal to 2% and the spray weight loss is less than or equal to 20% by adopting SH/T0109 and SH/T0643 tests.

6) The lubricating grease prepared by the invention has excellent service life, and is tested by DIN 51821 and FE9 tester F₅₀The service life is more than or equal to 200 h.

7) The production process of the invention can save working hours, improve the production efficiency by 20-30%, and the produced product has stable performance and good consistency.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. The examples do not show the specific techniques or conditions, according to the technical or conditions described in the literature in the field, or according to the product specifications.

In the present invention, the instruments and the like used are conventional products which are purchased from regular vendors, not indicated by manufacturers. The raw materials used in the invention can be conveniently bought in domestic product markets.