阅读说明：本技术 一种低摩擦系数复合磺酸钙润滑脂组合物及制备方法 (Low-friction-coefficient composite calcium sulfonate lubricating grease composition and preparation method thereof ) 是由 周钰 储友双 施鸣峻 吴宝杰 于 2020-06-19 设计创作，主要内容包括：本发明涉及一种低摩擦系数复合磺酸钙润滑脂组合物及其制备方法,按组合物的总重量计,包括以下组分：磺酸钙20～45％；转化促进剂1～2％；小分子酸0.5～4％；脂肪酸1～4％；氢氧化钙1～3％；碳酸氢盐0.5～1.5％；硝酸盐0.15～1.5％；添加剂0.2～1.5％；基础油余量；所述硝酸盐为0.05～0.5％的三价金属硝酸盐和0.1～1％的二价金属硝酸盐,所述三价金属硝酸盐为硝酸铝,所述基础油选自高粘度聚a烯烃油、高粘度酯类油和高粘度聚丁烯中的一种或多种,所述磺酸钙为高碱值合成磺酸钙,所述添加剂包括抗氧剂。本发明提供的润滑脂组合物能有效提升耐磨性能,适用于冶金、汽车及电动工具等行业中需要重载荷、抗磨损、长寿命的润滑部位,具有很大的实际应用价值和市场前景。(The invention relates to a low-friction coefficient composite calcium sulfonate lubricating grease composition and a preparation method thereof, wherein the low-friction coefficient composite calcium sulfonate lubricating grease composition comprises the following components in parts by weight: 20-45% of calcium sulfonate; 1-2% of a transformation promoter; 0.5-4% of small molecular acid; 1-4% of fatty acid; 1-3% of calcium hydroxide; 0.5-1.5% of bicarbonate; 0.15 to 1.5 percent of nitrate; 0.2-1.5% of an additive; the balance of base oil; the nitrate is 0.05-0.5% of trivalent metal nitrate and 0.1-1% of divalent metal nitrate, the trivalent metal nitrate is aluminum nitrate, the base oil is selected from one or more of high-viscosity polyalpha olefin oil, high-viscosity ester oil and high-viscosity polybutene, the calcium sulfonate is high-base-number synthetic calcium sulfonate, and the additive comprises an antioxidant. The lubricating grease composition provided by the invention can effectively improve the wear resistance, is suitable for lubricating parts needing heavy load, wear resistance and long service life in the industries of metallurgy, automobiles, electric tools and the like, and has great practical application value and market prospect.)

1. The low-friction-coefficient composite calcium sulfonate lubricating grease composition is characterized by comprising the following components in percentage by weight of the total weight of the composition:

the nitrate is 0.05-0.5% of trivalent metal nitrate and 0.1-1% of divalent metal nitrate, the trivalent metal nitrate is aluminum nitrate, the base oil is selected from one or more of high-viscosity polyalpha olefin oil, high-viscosity ester oil and high-viscosity polybutene, the calcium sulfonate is high-base-number synthetic calcium sulfonate, and the additive comprises an antioxidant.

2. The composition of claim 1, wherein the divalent metal nitrate is selected from one or two of zinc nitrate hexahydrate, magnesium nitrate, cobalt nitrate, nickel nitrate, and copper nitrate; preferably, the mass ratio of the divalent metal nitrate to the aluminum nitrate is 2: 1.

3. a grease composition according to claim 1 or 2, characterised in that the bicarbonate is calcium, sodium or ammonium bicarbonate, preferably calcium bicarbonate.

4. The composition of claim 3, wherein the total base number of the overbased synthetic calcium sulfonate is from 360 to 425 mgKOH/g; and/or the carbon number distribution C of alkyl benzene sulfonic acid in the high-base number synthetic calcium sulfonate₁₃-C₄₀The mixture of (1), required to have a carbon number of C₁₅-C₃₀Alkyl benzene sulfonic acid content ofThe total content of the benzenesulfonic acid is 60-80%.

5. A grease composition according to any one of claims 1-4, characterized in that the high viscosity polyalphaolefin oil is selected from one or more of PAO40, PAO60 and PAO 100; and/or the high-viscosity ester oil is selected from one or more of trimellitate, phthalate and complex ester; and/or the base oil is obtained by compounding and blending the high-viscosity poly-a olefin oil and the high-viscosity ester oil or the high-viscosity polybutene, wherein the mass fraction of the high-viscosity poly-a olefin oil is 50-80%; and/or the pour point of the base oil is not higher than-25 ℃.

6. A grease composition according to any one of claims 1-5, wherein the small molecule acid is selected from one or more of glacial acetic acid, propionic acid, succinic acid and boric acid, and the boric acid is 50-80% of the small molecule acid.

7. A grease composition according to any one of claims 1-6, characterised in that the fatty acid is hydrogenated castor oil, dodecahydroxystearic acid or stearic acid.

8. A grease composition according to any one of claims 1-7, characterized in that the conversion promoter is selected from one or more of methanol, ethanol, isopropanol, propylene glycol, n-butanol, hexanol and hexylene glycol.

9. A method for preparing a grease composition according to any one of claims 1 to 8, comprising the steps of:

step 1), mixing and stirring high-base-number synthetic calcium sulfonate, high-viscosity polyalpha olefin oil and a proper amount of water, and heating to 75-95 ℃;

step 2), adding small molecular acid, stirring for 3-10 min, adding a conversion promoter, stirring, and keeping the temperature at 75-95 ℃ for 1-2 h;

step 3), heating to 90-100 ℃, adding calcium hydroxide, nitrate and bicarbonate, and stirring for 30-60 min;

step 4), controlling the temperature to be 95-105 ℃, adding fatty acid and stirring, and keeping for 30-90 min;

step 5), heating to 120-140 ℃, keeping the temperature for 20-30 min, continuously heating to 150-200 ℃, keeping the temperature for 10-15 min, and adding the rest base oil;

and 6), cooling to below 150 ℃, adding the additive, stirring, thickening, and rolling to obtain the product.

10. A production method according to claim 9, wherein the grease composition is produced according to claim 1,

in the step 1), 20-30% of the total base number of the composition is 360-420 mgKOH/g of high-base number synthetic calcium sulfonate, 20-40% of the total weight of the composition is high-viscosity polyalpha olefin oil, and 10-20% of the total weight of the composition is water; and/or the presence of a gas in the gas,

in step 3), the order of adding the calcium hydroxide, the bicarbonate and the nitrate is as follows: adding calcium hydroxide, adding nitrate after 10-15 min, and adding bicarbonate after 5-10 min.

Technical Field

The invention relates to the technical field of lubricating grease, and particularly relates to a low-friction-coefficient composite calcium sulfonate lubricating grease composition and a preparation method thereof.

Background

Calcium sulfonates were originally used as detergents and rust inhibitors in lubricating oils. The research in the 50 s of the 20 th century and abroad shows that oil-soluble Newtonian calcium sulfonate can be used as a thickening agent to prepare calcium sulfonate-based lubricating grease, and the dropping point of the calcium sulfonate-based lubricating grease is higher than that of common calcium-based lubricating grease. In the next decade, researchers discovered a conversion method between newtonian calcium sulfonate and non-newtonian calcium sulfonate, and used high base number calcium petroleum sulfonate as a raw material, which resulted in the generation of high base number composite calcium sulfonate-based grease, but the grease had the disadvantages of viscous appearance and poor pumpability, and the application range was affected. Until Ron Muir (U.S. patent 4560489, Dec24,1985) and the like, high-alkalinity composite calcium sulfonate-based lubricating grease prepared by compounding high-base-number non-Newtonian calcium sulfonate with borate and fatty acid calcium soap reduces soap content, improves low-temperature pumping performance, shows the characteristics of excellent extreme pressure wear resistance, mechanical stability, colloid stability, rust resistance, water resistance, high temperature resistance and the like, is known as 'new generation high-efficiency lubricating grease', and leads the large-scale industrial production of the composite calcium sulfonate-based lubricating grease.

Chinese patent CN101993767A discloses a calcium carbonate-containing composite calcium sulfonate grease and a production method thereof, the method takes high-base number synthetic calcium sulfonate, base oil, boric acid and C12-C22 saturated stearic acid as basic components, and then nano calcium carbonate with the particle size of 5-300 nm is added into the calcium sulfonate grease, so as to obtain the novel composite calcium sulfonate-based grease. The extreme pressure wear resistance and the colloid stability of the lubricating grease produced by the method are improved, but the problems of high temperature resistance and hardening prevention of the lubricating grease are not improved. Chinese patent CN106497641A discloses a modified complex calcium sulfonate grease composition and a preparation method thereof, which improves the mechanical stability of grease and reduces the consistency change of grease during storage by improving the types and contents of transforming agent and complexing agent required in the preparation process, thereby achieving the purpose of reducing the loss at high temperature, but the problem of surface hardening is still not improved. The United states patent CN102703185A discloses a composite calcium sulfonate grease and a preparation method thereof, and the method is characterized in that an arylamine antioxidant is added in the thickening process, so that the operation can not only reduce the cost, but also improve the water resistance, heat resistance and lubricity of the product and reduce the loss of the product at high temperature. US5439602 focuses on the preparation of overbased sulfonates by reacting overbased calcium sulfonates with acids and adding antioxidants to provide rust protection, but not corrosion protection, to metals.

With the development of industrial modernization and the progress of the technological level, the requirements for lubricating grease are increasingly strict, such as universal joints, cross shafts, gears of electric tools and the like on automobiles, the reduction of friction coefficient is proposed to reduce the running resistance and control the temperature rise to prolong the service life of parts, and many high-end products and important parts even require life-long maintenance-free. The structural skeleton of the composite calcium sulfonate-based lubricating grease is different from other types of thickening agents, and calcium carbonate crystals and calcium sulfonate are mutually adsorbed to form colloidal particles or micelles with larger particle sizes, the colloidal particles or micelles form an interlaced gel structure by virtue of molecular force and ionic force, and the structural specificity of the colloidal particles or micelles causes the soap content to be higher than that of calcium-based, lithium-based and urea-based lubricating greases. The higher soap content makes the friction coefficient of the composite calcium sulfonate-based lubricating grease higher than that of other types of lubricating grease, and the conventional antifriction additive has no obvious effect and is difficult to meet the actual use effect. Therefore, it is very necessary to develop a complex calcium sulfonate grease with a low friction coefficient.

Disclosure of Invention

Aiming at the defects and shortcomings of poor wear resistance and the like in the prior art, the invention provides a low-friction-coefficient composite calcium sulfonate-based lubricating grease composition and a preparation method thereof.

One aspect of the present invention provides a low-friction coefficient calcium sulfonate complex grease composition, comprising the following components, by weight:

the nitrate is 0.05-0.5% of trivalent metal nitrate and 0.1-1% of divalent metal nitrate, the trivalent metal nitrate is aluminum nitrate, the base oil is selected from one or more of high-viscosity polyalpha olefin oil, high-viscosity ester oil and high-viscosity polybutene, the calcium sulfonate is high-base-number synthetic calcium sulfonate, and the additive comprises an antioxidant.

According to some preferred embodiments of the present invention, the divalent metal nitrate is selected from one or two of zinc nitrate hexahydrate, magnesium nitrate, cobalt nitrate, nickel nitrate and copper nitrate; preferably, the mass ratio of the divalent metal nitrate to the aluminum nitrate is 2: 1. in the present invention, when the divalent metal nitrate is selected from the above two, the two can be used simultaneously, and can be blended in an arbitrary ratio, and the effect is most excellent in the above preferable mass ratio. According to the invention, by introducing the metal nitrate, a component with an antifriction effect is formed in the preparation process, and a synergistic effect is formed with the lubricating grease, so that the original performance is not influenced, the friction coefficient of a lubricating part is reduced, and the wear resistance is improved.

According to some preferred embodiments of the present invention, the bicarbonate is calcium bicarbonate, sodium bicarbonate or ammonium bicarbonate, preferably calcium bicarbonate, which is more excellent.

According to some preferred embodiments of the present invention, the total base number of the overbased synthetic calcium sulfonate is from 360 to 425 mgKOH/g; and/or the carbon number distribution C of alkyl benzene sulfonic acid in the high-base number synthetic calcium sulfonate₁₃-C₄₀The mixture of (1), required to have a carbon number of C₁₅-C₃₀The content of the alkylbenzene sulfonic acid accounts for 60-80% of the total content of the alkylbenzene sulfonic acid.

According to some preferred embodiments of the present invention, the high viscosity polyalphaolefin oil is selected from one or more of PAO40, PAO60, and PAO 100; and/or the high-viscosity ester oil is selected from one or more of trimellitate, phthalate and complex ester; and/or the base oil is obtained by compounding and blending the high-viscosity poly-a olefin oil and the high-viscosity ester oil or the high-viscosity polybutene, wherein the mass fraction of the high-viscosity poly-a olefin oil is 50-80%; and/or the pour point of the base oil is not higher than-25 ℃.

According to some preferred embodiments of the present invention, the small molecule acid is selected from one or more of glacial acetic acid, propionic acid, succinic acid and boric acid, and the boric acid is 50-80% of the small molecule acid. Researches show that when the micromolecular acid is formed by compounding boric acid, one or more of glacial acetic acid, propionic acid and succinic acid and boric acid, and the boric acid accounts for 50-80%, the effect is better.

According to some preferred embodiments of the invention, the fatty acid is hydrogenated castor oil, dodecahydroxystearic acid or stearic acid.

According to some preferred embodiments of the present invention, the conversion promoter is selected from one or more of methanol, ethanol, isopropanol, propylene glycol, n-butanol, hexanol, and hexylene glycol; the antioxidant in the invention can be selected from the conventional types in the field, preferably one or two of diisooctyl diphenylamine, dioctyl diphenylamine, 2, 6-di-tert-butylphenol or 2, 6-di-tert-butyl-p-cresol, and the two can be used simultaneously and can be mixed according to any proportion.

Another aspect of the present invention is to provide a method for preparing the grease composition, comprising the steps of:

step 1), mixing and stirring high-base-number synthetic calcium sulfonate, high-viscosity polyalpha olefin oil and a proper amount of water, and heating to 75-95 ℃;

step 2), adding small molecular acid, stirring for 3-10 min, preferably 5min, adding a conversion promoter, stirring, and keeping the temperature at 75-95 ℃ for 1-2 h;

step 3), heating to 90-100 ℃, adding calcium hydroxide, nitrate and bicarbonate, and stirring for 30-60 min;

step 4), controlling the temperature to be 95-105 ℃, adding fatty acid and stirring, and keeping for 30-90 min;

step 5), heating to 120-140 ℃, keeping the temperature for 20-30 min, continuously heating to 150-200 ℃, keeping the temperature for 10-15 min, and adding the rest base oil;

and 6), cooling to below 150 ℃, adding the additive, stirring for preferably 0.5h, thickening, and rolling to obtain the oil.

According to some preferred embodiments of the present invention, in step 1), 20 to 30% by weight of the total base number of the composition is 360 to 420mgKOH/g of the high base number synthetic calcium sulfonate, 20 to 40% by weight of the total weight of the composition is high viscosity polyalpha olefin oil, and 10 to 20% by weight of the total weight of the composition is water.

According to some preferred embodiments of the invention, in step 3), the order of adding calcium hydroxide, bicarbonate and nitrate is: adding calcium hydroxide, adding nitrate after 10-15 min, and adding bicarbonate after 5-10 min.

According to the invention, the small molecule acid is preferably diluted 2 to 3 times with water in advance, the calcium hydroxide is diluted 1 to 3 times with water in advance, the nitrate is diluted 1 time with water in advance, and the bicarbonate is diluted 1 to 2 times with water in advance.

According to the invention, the lubricating grease product forms a component with an antifriction effect in the preparation process, so that the friction coefficient of a lubricating part can be effectively reduced, and the wear resistance is improved.

In the invention, the alkaline condition in the preparation process of the composite calcium sulfonate is utilized, the metal salt which is easy to dissolve in water is introduced, and the reaction forms the antifriction component with synergistic effect to reduce the friction coefficient of the lubricating grease, so that the lubricating grease is very suitable for lubricating parts which need heavy load, abrasion resistance and long service life in industries such as metallurgy, automobile and electric tools, and has great practical application value and market prospect.

The invention has the beneficial effects that: the lubricating grease prepared by adopting the preparation process and the raw materials with special requirements has better water resistance, shearing resistance and extreme pressure abrasion resistance than the conventional composite calcium sulfonate lubricating grease; through an SRV test, the friction coefficient of the lubricating grease is reduced by 15-35% after a new component is introduced; due to the synergistic effect of the new component and the lubricating grease structure, the soap content of the lubricating grease can be reduced by 10-20%.

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. In the analysis and test of the embodiment of the invention, the friction coefficient is measured by adopting an SRV-4 type high-frequency linear vibration testing machine produced by OPTIMOL company in Germany, and the test standard method is NB/SH/T0721-. The test conditions of the SH/T0338 method are as follows: the temperature is 50 ℃, the frequency is 50Hz, the load is 200N, and the test time is 2 h.