阅读说明：本技术 一种复合钙基润滑脂及其制备方法 (Composite calcium-based lubricating grease and preparation method thereof ) 是由 廖顺知 阎君 喻波 于 2020-06-23 设计创作，主要内容包括：本发明涉及一种新型复合钙基润滑脂及其制备方法,该新型复合钙基润滑脂由下列含量按重量百分比计的原料组成：基础液50%~80%、新型复合钙基复合钙皂稠化剂20%~40%、功能改进添加剂0.1%~5%。该新型复合钙基润滑脂的特点是采用新型复合钙基稠化剂,通过引入苯硼酸钙-磷酸钙组分,提高复合钙基稠化剂的抗摩擦磨损能力和抗氧化安定性能力,且改善复合钙基润滑脂的储存硬化问题,同时充分利用复合钙基稠化剂优异的极压抗磨性、机械安定性和抗水性等特点,使所制备的一种新型复合钙基润滑脂可满足重载车辆轮毂轴承高温高速、高可靠性和长寿命的使用需求。(The invention relates to a novel composite calcium-based lubricating grease and a preparation method thereof, wherein the novel composite calcium-based lubricating grease is prepared from the following raw materials in percentage by weight: 50-80% of base liquid, 20-40% of novel composite calcium-based composite calcium soap thickening agent and 0.1-5% of function improvement additive. The novel composite calcium-based lubricating grease is characterized in that a novel composite calcium-based thickening agent is adopted, the friction wear resistance and the oxidation stability resistance of the composite calcium-based thickening agent are improved by introducing a calcium phenylboronate-calcium phosphate component, the storage hardening problem of the composite calcium-based lubricating grease is improved, and meanwhile, the excellent extreme pressure wear resistance, mechanical stability, water resistance and other characteristics of the composite calcium-based thickening agent are fully utilized, so that the prepared novel composite calcium-based lubricating grease can meet the use requirements of high temperature, high speed, high reliability and long service life of hub bearings of heavy-duty vehicles.)

1. The composite calcium-based lubricating grease comprises base oil, a composite calcium soap thickening agent and an additive, and is characterized in that the base oil is a composition of paraffin-based mineral oil and synthetic oil; the composite calcium soap thickening agent is generated by the common reaction of calcium hydroxide, high molecular acid, medium molecular acid and low molecular acid; the low molecular acid is a mixture of phosphoric acid and acetic acid; the medium molecular acid is phenylboronic acid; the polymer acid is one or more of sebacic acid, stearic acid and dodecahydroxystearic acid; the additives include antioxidant additives and preservative additives.

2. The grease of claim 1, wherein the base oil comprises 60% to 80% by weight of the total weight of the grease; the composite calcium soap thickener accounts for 20-40% of the total weight of the lubricating grease; the additive accounts for 0.5-5% of the total weight of the lubricating grease.

3. The grease of claim 1, wherein the base oil has a mass ratio of paraffin-based mineral oil to synthetic oil of (55-65) to (8-12); the paraffin-based mineral oil is a combination of 150BS base oil and 500SN base oil; the mass ratio of the 150BS base oil to the 500SN base oil is (5-7) to 6; the synthetic oil is a combination of ester type synthetic oil and hydrocarbon type synthetic oil; the mass ratio of the ester type synthetic oil to the hydrocarbon type synthetic oil is (1-2) to (1-2).

4. A grease according to claim 3, wherein the ester-type synthetic oil is a polyol ester; the hydrocarbon-based synthetic oil is polyisobutylene; preferably, the molecular weight of the polyisobutylene is 2400.

5. The grease of claim 1, wherein the complex calcium soap thickener comprises the following components in percentage by weight: 6-12% of calcium hydroxide, 3-6% of high molecular acid, 2-4% of medium molecular acid and 8-16% of low molecular acid.

6. The grease of claim 1, wherein the additive consists of 0.5-3% of an antioxidant additive and 0.5-3% of a corrosion protection additive; the antioxidant additive is one or a mixture of phenolic antioxidant additive, amine antioxidant additive or phenolic amine antioxidant additive; the anticorrosion and protective additive is one or a mixture of benzotriazole derivatives, thiadiazole derivatives or other metal passivators.

7. A method of preparing the complex calcium-based grease according to claim 1, comprising the steps of:

firstly, mixing part of base oil and part of calcium hydroxide according to the weight ratio; then sequentially adding low molecular acid, medium molecular acid, high molecular acid, the rest calcium hydroxide and the rest base oil; then heating, dehydrating and heating for refining for a certain time;

step two, after the reaction is finished, cooling, adding an additive, uniformly mixing, homogenizing, heating to a specified temperature, and shearing;

and step three, degassing, filtering and filling the product obtained in the step two to obtain the composite calcium-based lubricating grease.

8. The method of claim 7, wherein the portion of base oil and the portion of calcium hydroxide in step one are 90% base oil and 90% calcium hydroxide.

9. The method according to claim 7, wherein the reaction temperature of the acid added in the step one is 20 to 120 ℃, and the reaction time is 10 to 60 minutes for each acid added; preferably, the temperature of adding the low molecular acid in the first step is 30-70 ℃; preferably, the medium molecular acid is added in the first step at 70-90 ℃; preferably, the polymeric acid is added in the first step at 90-120 ℃.

10. The production method according to claim 7, wherein the remaining calcium hydroxide is previously prepared as an aqueous solution and then added to the system in the form of an aqueous solution; adding the rest calcium hydroxide to react at the temperature of 120-140 ℃; the dehydration reaction in the first step is carried out at 130-180 ℃; the reheating refining reaction temperature in the first step is 200-250 ℃, and the reaction time is 5-20 minutes; the temperature of the cooling in the second step is 80-120 ℃; the designated temperature in the second step is 80-120 ℃; and the operation of the third step is carried out at 80-120 ℃.

Technical Field

The invention relates to lubricating grease and a preparation method thereof, in particular to novel composite calcium-based lubricating grease and a preparation method thereof.

Background

The most demanding part of the heavy-duty vehicle is the hub bearing, and the classification of the grease for the vehicle hub according to the american grease society (NLGI) is adopted, and the GC type of the hub bearing grease is generally selected for the heavy-duty vehicle in the market at present. Because of the important role that grease plays in hub bearings, mainly for anti-wear, anti-friction and sealing purposes, it is often referred to as the "fifth component" of the hub bearing. Therefore, the lubricating grease has very important function for ensuring the normal operation of the vehicle hub bearing^[1]。

In China, four and fifty years in the 20 th century, the composite calcium-based composite calcium soap thickening agent is used as the lubricating grease for the wheel hub bearing of the vehicle^[3]. The calcium-based composite calcium soap thickener has good water resistance, but because the performance of the thickener is insufficient, an additive needs to be added to improve the antirust property, the thickener cannot resist high temperature, the structure of the calcium soap composite calcium soap thickener above 79 ℃ is unstable, and the thickener can be hardened at high temperature. The reason why the quality of the calcium complex grease is poor and the quality of the lithium complex grease is that the soap fiber structure of the calcium complex grease is not complex and stable as that of the lithium complex grease. The traditional composite calcium-based lubricating grease is formed by attaching calcium acetate molecules on organic acid calcium soap fibers, and the structure has better quality and performance than the common calcium-based lubricating grease. However, the soap fibers of the lithium complex grease are of an organic integral network structure, and the soap fibers are connected with each other, so that the structure of the lithium complex grease is more complex and stable. Therefore, the traditional complex calcium-based lubricating grease is gradually replaced by complex lithium-based lubricating grease with better performance. The lithium-based lubricating grease has a high dropping point and a use temperature range: the temperature is-20 to 120 ℃, and the water resistance, the mechanical stability, the rust resistance and the oxidation stability are good; however, the lithium-based composite calcium soap thickener has the defect of poor wear resistance for a long time, is not suitable for being mixed with other lubricating grease, is easy to separate oil when being stored, has a small use temperature range and poor water resistance compared with the non-metallic soap lubricating grease, and cannot meet the increasingly rigorous requirements of modern industry. And the price of lithium hydroxide in the current market rises by about 5 times, and the cost of the lithium-based lubricating grease is greatly improved. Reason for the market, lithiumThe market price of the base grease cannot rise synchronously with the price of the lithium hydroxide, and the profit margin of production enterprises is squeezed.

According to the development trend of hub bearings: unitization, high-temperature and high-speed, integral sealing and low micro-dynamic abrasion^[2]And combines the development current situations of the lubricating grease industry and the automobile industry. In order to prolong the grease replacement period of the hub bearing, solve the high-temperature and high-speed loss and maintain the good lubrication requirement of the bearing, the development of the composite calcium-based lubricating grease with more excellent performance is necessary.

The traditional composite calcium-based lubricating grease is acetic acid composite calcium-based lubricating grease, and acetic acid has active chemical property, can quickly react with calcium hydroxide and then is crystallized and separated out. In order to control the crystallization rate of calcium acetate, the operator must carefully handle it, otherwise it is prone to failure. In order to facilitate production and improve the quality of the composite calcium, the invention produces the composite calcium-based lubricating grease by introducing the calcium phenylboronate and the calcium phosphate, improves the friction and wear resistance and the oxidation stability resistance of the composite calcium-based lubricating grease, improves the storage hardening problem of the composite calcium-based lubricating grease, and fully utilizes the characteristics of excellent extreme pressure wear resistance, mechanical stability, water resistance and the like of the composite calcium-based lubricating grease, so that the prepared novel composite calcium-based lubricating grease can meet the use requirements of high temperature, high speed, high reliability and long service life of a hub bearing of a heavy-duty vehicle.

[1] Xixiaocang blue and its governing yellow Bo, the grease lubrication test research of automobile parts [ M ]. Qinghua university Press, 2014.

[2] Jutingbin. lubricating grease technical grand [ M ] chinese petrochemical press, 2015.

[3] Liu shows the Limb Liangsen Wang Lei Chunmei Sunhua Wei. automobile hub bearing grease reviews [ J ] oil use omnibearing 2006(4).

Disclosure of Invention

The invention aims to provide composite calcium-based lubricating grease prepared by adopting a novel composite calcium-based thickening agent and a preparation process thereof.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a composite calcium-based lubricating grease comprises base oil, a composite calcium soap thickening agent and an additive, wherein the base oil is a composition of paraffin-based mineral oil and synthetic oil; the composite calcium soap thickening agent is generated by the common reaction of calcium hydroxide, high molecular acid, medium molecular acid and low molecular acid; the low molecular acid is a mixture of phosphoric acid and acetic acid; the medium molecular acid is phenylboronic acid; the polymer acid is one or more of sebacic acid, stearic acid and dodecahydroxystearic acid; the additives include antioxidant additives and preservative additives.

Preferably, the base oil in the grease accounts for 60-80% of the total weight of the grease; the composite calcium soap thickener accounts for 20-40% of the total weight of the lubricating grease; the additive accounts for 0.5-5% of the total weight of the lubricating grease.

Preferably, the mass ratio of the paraffin-based mineral oil to the synthetic oil in the base oil is (55-65): (8-12).

Preferably, the paraffinic mineral oil is a combination of 150BS base oil, 500SN base oil.

Preferably, the mass ratio of the 150BS base oil to the 500SN base oil is (5-7): 6.

Preferably, the synthetic oil is a combination of both an ester-type synthetic oil and a hydrocarbon-type synthetic oil.

Preferably, the mass ratio of the ester-type synthetic oil to the hydrocarbon-type synthetic oil is (1-2): (1-2).

Preferably, the mass ratio of the ester-type synthetic oil to the hydrocarbon-type synthetic oil is 1: 1.

Preferably, the ester-type synthetic oil is a polyol ester.

Compared with other ester synthetic oils, the polyol ester has particularly outstanding oxidation stability. In this compatibility, the high temperature performance of the grease can be improved.

Preferably, the hydrocarbon-based synthetic oil is polyethylene.

Further preferably, the hydrocarbon-based synthetic oil is PIB 2400.

PIB (polyisobutylene) has excellent adhesiveness, can be applied to a lubricating grease system to enable the lubricating grease to be better adhered to a part needing lubrication, and has excellent shear stability. And the molecular weight of the PIB2400 is larger than that of the common PIB, so that the adhesion performance is better, and meanwhile, the required dosage is correspondingly low due to the fact that the molecular weight reaches 2400, and the synthesis of other performances of a system is facilitated.

Preferably, the composite calcium soap thickening agent comprises the following components in percentage by weight: 6-12% of calcium hydroxide, 3-6% of high molecular acid, 2-4% of medium molecular acid and 8-16% of low molecular acid.

The low molecular acid is phosphoric acid and acetic acid; the invention adopts calcium phosphate generated by the reaction of phosphoric acid and calcium hydroxide as one of the components of the novel composite calcium soap thickening agent, and partially replaces the low molecular acid component of the original calcium acetate, so that the lubricating grease has more excellent wear-resistant and friction-reducing properties. Meanwhile, as part of the calcium acetate component is replaced by the calcium phosphate component, the defect of water absorption of acetic acid is greatly reduced. The problem of water absorption hardening of the composite calcium-based thickening agent is effectively improved.

The medium molecular acid is phenylboronic acid; the invention adopts calcium phenylboronate generated by the reaction of phenylboronic acid and calcium hydroxide as one of the components of the novel composite calcium soap thickening agent, so that the lubricating grease has more excellent extreme pressure wear resistance. Meanwhile, due to the existence of benzene rings, the lubricating grease has better anti-oxidation stability.

Preferably, the additive consists of 0.5 to 3 percent of antioxidant additive and 0.5 to 3 percent of anticorrosion protective additive.

Preferably, the antioxidant additive is one or more of a phenolic, an amine, or a mixture of phenolic and amine antioxidant additives.

Preferably, the corrosion protection additive is a mixture of one or more of a benzotriazole derivative, a thiadiazole derivative or other metal deactivator.

The method for preparing the composite calcium-based lubricating grease comprises the following steps:

firstly, mixing part of base oil and part of calcium hydroxide according to the weight ratio; then sequentially adding low molecular acid, medium molecular acid, high molecular acid, the rest calcium hydroxide and the rest base oil; then heating, dehydrating and heating for refining for a certain time;

step two, after the reaction is finished, cooling, adding an additive, uniformly mixing, homogenizing, heating to a specified temperature, and shearing;

and step three, degassing, filtering and filling the product obtained in the step two to obtain the composite calcium-based lubricating grease.

Preferably, the part of the base oil and the part of the calcium hydroxide in the first step are 90% of the base oil and 90% of the calcium hydroxide.

The calcium hydroxide is added in two parts, and the front part is only added by 90 percent, so that the calcium hydroxide is in an acid atmosphere when the salt generated by the high molecular acid and the salt generated by other low molecular acid are subjected to a composite reaction to form a large space structure, and thus the composite product has higher hardness and better composite effect.

Preferably, the reaction temperature of the acid added in the step one is 20-120 ℃, and the reaction time is 10-60 minutes for each acid added.

Preferably, the temperature of adding the low molecular acid in the first step is 30-70 ℃; the low molecular acid volatilizes when the temperature is too high.

Preferably, the medium molecular acid is added in the first step at 70-90 ℃.

Preferably, the polymer acid is added in the step one at 90-120 ℃, is solid at normal temperature and can be melted into liquid at high temperature.

Each acid addition results in a low molecular weight salt, so the other components are added at intervals of 10-60 minutes. And finally the low molecular weight salts will agglomerate by physical intermolecular forces into high molecular weight stable polymers with large steric structure.

Preferably, the remaining calcium hydroxide is prepared in advance as an aqueous solution and then added to the system in the form of an aqueous solution.

Preferably, the reaction temperature of the residual calcium hydroxide added in the step one is 120-140 ℃.

The higher the temperature at which the remaining calcium hydroxide is added, the more complete the reaction. And after the reaction is finished, water is redundant in the system, the high temperature is favorable for volatilizing the water, primary dehydration is finished, and system impurities are reduced. However, when the temperature is higher than 140 ℃, side reactions are too much, and the reaction is not easy to control.

Preferably, the dehydration reaction in the first step is carried out at 130-180 ℃.

At the moment, secondary dehydration is carried out, and no water residue is ensured in the lubricating grease. In this system, moisture affects not only the lubricity of the grease but also causes rusting easily.

Preferably, the reheating refining reaction temperature in the first step is 200-250 ℃, and the reaction time is 5-20 minutes.

The space structure can be effectively fixed by the refined high temperature.

Preferably, the temperature reduction temperature in the second step is 80-120 ℃.

Preferably, the homogenization mode in the step two is three-roll milling, and the milling times are required to be 2-4 times.

Preferably, the specified temperature in the second step is 80-120 ℃.

Preferably, the operation of the third step is carried out at 80-120 ℃.

The preparation of the complex calcium grease of the present application is further explained below:

the method for preparing the novel composite calcium-based lubricating grease comprises the following steps:

(1) feeding: adding 50-60% of base oil and 5.4-10.8% of calcium hydroxide into a reaction kettle, and uniformly mixing;

(2) acid-base reaction: after being mixed evenly, 8 to 16 percent of low molecular acid, 2 to 4 percent of medium molecular acid and 3 to 6 percent of high molecular acid are added in sequence; the temperature of the acid-base reaction is 20-120 ℃, and the reaction time is 10-60 minutes for each acid added;

(3) and carrying out composite reaction: after the step (2) is finished, adding 0.6-1.2% of calcium hydroxide; carrying out a composite reaction at 90-150 ℃;

(4) and (3) dehydration reaction: after the step (3) is finished, adding 5-15% of base oil, heating and dehydrating; the dehydration reaction is carried out at 130-180 ℃;

(5) and refining reaction: after the step (4) is finished, heating to the refining temperature, and reacting for a certain time; the refining temperature is 200-250 ℃, and the reaction time is 5-20 minutes;

(6) adding an agent: after the step (5) is finished, cooling to a specified temperature, wherein the specified temperature is 80-120 ℃; adding a function improvement additive;

(7) homogenizing: after the step (6) is finished, uniformly mixing, and grinding and homogenizing by a three-roller machine, wherein the grinding times are required to be 2-4;

(8) and shearing: after the step (7) is finished, pouring the homogenized material into a blending kettle, and heating to a specified temperature, wherein the specified temperature is 80-120 ℃; shearing by a static shearer;

(9) and degassing: after the step (8) is finished, performing product degassing treatment;

(10) and filling: and (5) after the step (9) is finished, filtering and filling the product.

The operation in the step (9) and the operation in the step (10) are both carried out at the temperature of 80-120 ℃.

The invention relates to novel composite calcium-based lubricating grease prepared by adopting a novel composite calcium soap thickening agent. On the basis of ZL 201010502273.8 composite calcium-based lubricating grease and a production process thereof, the invention improves the friction and wear resistance and oxidation stability resistance of the composite calcium soap thickener by introducing calcium phenylborate and calcium phosphate components, improves the storage hardening problem of the composite calcium soap thickener, and makes full use of the excellent extreme pressure wear resistance, mechanical stability, water resistance and other characteristics of the composite calcium soap thickener, so that the prepared novel composite calcium-based lubricating grease can meet the use requirements of heavy-duty vehicle hub bearings on high temperature, high speed, high reliability and long service life.

Compared with the prior art, the invention has the following beneficial effects:

1. the phosphoric acid-phenylboronic acid composite calcium-based lubricating grease prepared by the invention utilizes phosphoric acid and phenylboronic acid to partially replace a low molecular acid component of the original calcium acetate, so that the lubricating grease has more excellent wear-resistant and friction-reducing properties and extreme pressure wear-resistant properties. And because part of the calcium acetate component is replaced by the calcium phosphate component, the problem of water absorption hardening of the composite calcium soap thickening agent is effectively improved; meanwhile, due to the existence of benzene rings, the lubricating grease has better anti-oxidation stability; meanwhile, the calcium phosphate and the calcium phenylboronate supplement each other in the invention, and the calcium phosphate and the calcium phenylboronate mutually promote the addition of performances, thereby having obvious synergistic effect.

2. The PIB2400 adopted by the invention can effectively improve the adhesion of the lubricating grease and improve the high-speed resistance of the product.

In a word, the phosphoric acid-phenylboronic acid composite calcium-based lubricating grease prepared by the invention has excellent extreme pressure abrasion resistance, shear stability, water resistance and oxidation resistance stability, further improves the storage hardening problem of the composite calcium-based lubricating grease, and can meet the use requirements of high temperature, high speed, high reliability and long service life of a hub bearing of a heavy-duty vehicle.

Detailed Description

The present invention will be described in detail with reference to examples. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.